Control device, system, method, and program

Abstract

The present invention provides a control device, a system, a method, and a program that make it possible to efficiently acquire data significant for identifying the structure of a macromolecule in a solution with a resolution greater than 30 Å. Provided is a control device 200 for controlling an X-ray analysis device, comprising: a data conversion unit 223 that converts, into profiles, sample solution data and reference solution data acquired from the X-ray analysis device at different points in time; a first indicator calculation unit 232 that calculates a first indicator representing fluctuation of intensity in the time axis direction on the basis of the profile of at least one of the sample solution data and the reference solution data out of the profiles obtained through the conversion; a first indicator determination unit 234 that determines whether or not the calculated first indicator is within a predetermined range; and a device control unit 268 that terminates the measurement by the X-ray analysis device if the first indicator is not within the predetermined range.

Description

Control device, system, method and program

[0001] The present invention relates to a control device, a system, a method, and a program for controlling a measuring device that irradiates X-rays onto a polymer in a solution and detects a scattering image.

[0002] X-ray solution scattering (Bio-SAXS) is a known method for observing biopolymers in solution (Non-Patent Document 1). Bio-SAXS allows for the determination of the molecular structure of biopolymers in solution by analyzing the scattering image obtained by irradiating a sample solution with X-rays or neutrons. This method does not require crystallization or freezing of the sample, as in single crystal structure analysis or cryo-electron microscopy, and allows for the observation of the intact structure of the sample in solution. Bio-SAXS is often used to identify the arrangement of subunits in relatively large molecular complexes and structural changes due to ligand binding.

[0003] Sachiko Fujima, "Practical application of Bio-SAXS for structural analysis of protein complexes," Journal of the Crystallographic Society of Japan, Vol. 61, No. 2 (2019), pp. 79-80

[0004] However, the resolution of Bio-SAXS as described in Non-Patent Document 1 is limited to the extent that it can identify the general molecular shape of biological components. Figure 14 shows the correspondence relationship between the resolution that can be identified and the scattering profile. As shown in Figure 14, the precision of the structure that can be identified by Bio-SAXS is limited to approximately 30 Å, which is equivalent to the resolution.

[0005] Meanwhile, in the field of biopharmaceuticals, for example, there is a need to identify structures of molecules and molecular complexes with a size of 30 Å or less. One example of quality control is inspecting the integrity of the connections between the constituent proteins of designed virus particles. For such structural analysis, MAXS (Middle Angle X-ray Scattering) is used, which analyzes the scattering intensity profile at wide angles. Because the intensity of such scattering intensity profiles at wide angles is low, it takes time to collect meaningful data. However, because biopolymers are prone to degradation, data quality deteriorates over long periods of measurement.

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide a control device, system, method, and program that can efficiently acquire significant data for identifying the structure of a polymer in a solution with a resolution exceeding 30 Å.

[0007] (1) In order to achieve the above object, the control device of the present invention is a control device that controls an X-ray analysis device, and is characterized by comprising: a data conversion unit that converts sample solution data and reference solution data acquired from the X-ray analysis device into profiles at each time; a first index calculation unit that calculates a first index representing intensity fluctuations in the time axis direction based on a profile of at least one of the solution data in the converted profiles; a first index determination unit that determines whether the calculated first index is within a predetermined range; and an apparatus control unit that terminates measurement by the X-ray analysis device when the first index is not within the predetermined range.

[0008] (2) The control device of the present invention is also characterized in that the first index calculation unit calculates the first index for a differential profile between a profile of the sample solution data and a profile of the reference solution.

[0009] (3) Furthermore, the control device of the present invention is characterized in that the first index calculation unit calculates the first index for a profile of the reference solution.

[0010] (4) Furthermore, the control device of the present invention further includes a second index calculation unit that calculates a second index representing the ratio of intensity data to intensity fluctuations in the scattering angle direction based on an integrated profile of at least one of the solution data obtained from the converted profile, and a second index determination unit that determines whether the calculated second index is on an increasing trend, and the device control unit is characterized in that it terminates measurement by the X-ray analysis device when the calculated second index is not on an increasing trend.

[0011] (5) Furthermore, the control device of the present invention is characterized in that the second index calculation unit calculates the second index for a differential profile between a profile of the sample solution data and a profile of the reference solution.

[0012] (6) Furthermore, the control device of the present invention is characterized in that the second index determination unit determines whether the calculated second index is greater than or equal to a threshold value, and the device control unit terminates measurement by the X-ray analysis device when the calculated second index is greater than or equal to the threshold value.

[0013] (7) Furthermore, the control device of the present invention further includes a measurement time determination unit that determines whether the measurement time exceeds a predetermined value, and the device control unit is characterized in that it terminates the measurement by the X-ray analysis device when the measurement time exceeds the predetermined value.

[0014] (8) The control device of the present invention is further characterized by including an analysis data generation unit that adjusts the scale so that the average values ​​of the sample solution data and the reference solution data match before subtraction within the wide-angle range of the scattering vector.

[0015] (9) The control device of the present invention is further characterized by including an input / output control unit that outputs a plot of the calculated first index against time to an output device during measurement.

[0016] (10) The control device of the present invention is further characterized by including an input / output control unit that outputs a plot of the calculated second index against time to an output device during measurement.

[0017] (11) Furthermore, the system of the present invention is a system for performing X-ray analysis, characterized in that it comprises an X-ray analysis device that irradiates X-rays onto a sample and detects a scattering image, and a control device described in any one of (1) to (10) above that controls the X-ray analysis device.

[0018] (12) Furthermore, a method of the present invention is a method for controlling an X-ray analysis apparatus, characterized in that it includes the steps of converting sample solution data and reference solution data acquired from the X-ray analysis apparatus into profiles at each time point, calculating a first index representing intensity fluctuations in the time axis direction based on at least one of the solution data profiles of the converted profiles, determining whether the calculated first index is within a predetermined range, and performing processing to terminate measurement by the X-ray analysis apparatus if the first index is not within the predetermined range.

[0019] (13) Furthermore, a program of the present invention is a program for controlling an X-ray analysis apparatus, and is characterized in that it causes a computer to execute the following processes at each time: converting sample solution data and reference solution data acquired from the X-ray analysis apparatus into a profile; calculating a first index representing intensity fluctuations in the time axis direction based on at least one of the converted solution data profiles; determining whether the calculated first index is within a predetermined range; and terminating measurement by the X-ray analysis apparatus if the first index is not within the predetermined range.

[0020] 1 is a schematic diagram showing a control system according to the present invention. FIG. 2 is a perspective view showing an X-ray analysis apparatus according to the present invention. FIG. 3 is a block diagram showing the configuration of a control system. FIG. 4 is a flowchart showing the operation of a control apparatus according to a first embodiment. FIG. 5 is a schematic diagram showing a process for acquiring a scattering image. (a) to (c) are a scattering image, a β-direction profile, and a q-direction profile, respectively. (a) to (c) are diagrams showing a q-direction profile for each acquisition of a scattering image, acquisition of measurement data at each time, and generation of a difference profile. FIG. 6 is a graph showing X-ray intensity at a predetermined wavenumber versus measurement time. FIG. 7 is a diagram showing a table of extracted parameters. FIG. 8 is a graph showing an example of the progression of σt(I / σ). FIG. 9 is a graph showing an example of the progression of I / σ. FIG. 10 is a flowchart showing the operation of a control apparatus according to a second embodiment. (a) to (c) are schematic diagrams showing a graph plotting σt(I / σ), a graph plotting I / σ, and a visualized structural model, respectively, for an example. FIG. 11 is a diagram showing the correspondence between an identifiable size and a scattering profile.

[0021] Next, an embodiment of the present invention will be described with reference to the drawings. To facilitate understanding of the description, the same reference numerals are used to designate the same components in the drawings, and duplicated descriptions will be omitted.

[0022] [A Situation Specific to the X-ray Field] In the field of X-rays, the process of reading developed and fixed film with a scanner has been followed for many years. As a result, the measurement time span, including not only diffraction but also imaging, is long, and the accumulated detection data is not evaluated in real time. Under this handling, even if an abnormality occurs during the measurement, it cannot be detected until the measurement or analysis is completed, and samples collected over months may be damaged before sufficient data is obtained.

[0023] In a field where measurement is typically viewed as a gamble, the idea of ​​setting a certain level of required quality for a measurement and then exposing the sample to that level represents a major shift in thinking. In particular, in solution scattering measurements, X-ray irradiation inevitably damages biopolymers, but the scattering intensity is weak, making it difficult to obtain a sufficient signal-to-noise ratio, necessitating excessive exposure times. The present invention's real-time evaluation of measurement results and the ability to flexibly decide whether to continue or terminate the measurement at the minimum necessary level are significant because they allow the same sample to be used not only for this scattering measurement but also for other biological experiments after the measurement.

[0024] [Principle] MAXS analyzes the structure of polymers in solution at 10 Å (q = 0.63 A －１ To identify the scattering intensity with a resolution of approximately 100%, it is necessary to efficiently collect measurement data from the reference solution and the sample solution and calculate data for analysis. In this invention, scattering images of the reference solution and the sample solution are acquired as measurement data, and a decision is made simultaneously based on the measurement data whether or not the measurement should continue. In this case, it is confirmed whether there is a prospect of obtaining sufficient measurement data for analysis at this stage, and whether sufficient measurement data for analysis has already been obtained. This two-stage decision makes it possible to efficiently obtain meaningful data. The configuration and operation for achieving this are described in detail below.

[0025] [First Embodiment] [Control System] Fig. 1 is a schematic diagram showing a control system 10. The control system 10 includes an X-ray analysis apparatus 100 and a control device 200. The X-ray analysis apparatus 100 irradiates a sample S0 with X-rays and detects small-angle scattered X-rays. The sample S0 is preferably a polymer in solution, particularly a biopolymer. This is particularly effective when the sample S0 is a pharmaceutical molecule, molecular complex, or structure in solution that requires structural analysis of 30 Å or less.

[0026] The target solutions include sample solutions and reference solutions. A sample solution is a solution containing a sample, for example, a solution containing a biopolymer and a special component for retaining the biopolymer. A reference solution is a solution obtained by removing the sample from the sample solution. For example, the reference solution in the above example is a solution that does not contain a biopolymer but contains a special component. Although a solution containing components similar to those of the sample solution may be prepared separately as the reference solution, it is preferable to use a solution obtained by separating the sample from the sample solution.

[0027] The control device 200 is composed of a computer 210, an input device 280, and an output device 290, and controls the operation of the X-ray analysis device 100, and also acquires and processes measurement data from the X-ray analysis device 100.

[0028] The X-ray analysis apparatus 100 includes an X-ray generation unit 110, a sample loading mechanism 120, a detector 130, and a control unit 140. The X-ray generation unit 110 has an X-ray source 111 and irradiates X-rays onto a sample S0. The target of the X-ray source 111 is preferably Cu, but Co may also be used. The sample loading mechanism 120 sends a sample solution containing a sample or a reference solution without a sample, along with the sample holding tube, to the X-ray irradiation position. The detector 130 detects X-rays scattered by the sample S0 and transmits the obtained measurement data to a computer 210.

[0029] In the above configuration, one detector 130 is provided for one X-ray beam emitted from the X-ray source 111, but other configurations may also be employed. For example, the X-ray analysis apparatus 100 may be configured to emit two equal beams in the same direction using a mirror or a slit and detect the scattered rays thereof with one detector. Alternatively, the X-ray analysis apparatus 100 may be configured to emit two equal beams in opposite directions and detect the scattered rays thereof with two detectors, respectively.

[0030] The computer 210 is, for example, a PC, and is configured with a processor that executes processing, and a memory or hard disk that stores programs and data, etc. The computer 210 receives input from the user via an input device 280 such as a keyboard or mouse.

[0031] The computer 210 may be a server device located on the cloud. In addition, in terms of processing load, the function of controlling the operation of the X-ray analysis apparatus 100 and the function of processing the measurement data may be separated, with the control being performed by a PC installed on-site and the data processing being performed by a server device.

[0032] 2 is a perspective view showing an X-ray analysis apparatus 100. The X-ray analysis apparatus 100 includes an X-ray source 111, an optical system 115, a Kratsky block 117, a sample holding tube 125, and a detector 130. The X-ray source 111 is a line radiation source or a point radiation source, and emits a diverging beam. The optical system 115 is, for example, a KB parallel type or a serial type optical system.

[0033] The pair of Kratky blocks 117 interact with the X-rays through their respective edges to define one side of the X-ray beam, thereby eliminating parasitic scattering from the irradiated X-rays. The sample holding tube 125 delivers and holds 5 to 10 μl of solution.

[0034] The detector 130 detects the X-rays scattered by the solution. The X-ray analysis device 100 transmits the detected scattered image to the control device 200. The detected scattered image is transmitted as measurement data at predetermined time intervals t.

[0035] 3 is a block diagram showing the control system. The control device 200 controls the X-ray analysis device 100 and acquires a scattering image. The functions of the control device 200 are mainly realized by a computer 210.

[0036] The computer 210 includes an input / output control unit 211, a measurement control unit 215, a measurement data storage unit 217, a data conversion unit 223, a differential profile generation unit 225, a first index calculation unit 232, a first index determination unit 234, a second index calculation unit 243, a second index determination unit 247, a measurement time determination unit 255, an apparatus control unit 268, and an analysis data generation unit 272. Each unit can send and receive information via a control bus L.

[0037] The input / output control unit 211 accepts input from the input device 280 and controls output to the output device 290. The input / output control unit 211 can accept input of measurement conditions, for example. The measurement conditions include the intensity of the generated X-rays, the position of the Kratky block, the blank position where the X-rays are irradiated, the position of the solution, the arrangement of the detector, and the measurement time t when the scattering image is obtained. The input / output control unit 211 can also output the progress of each index and the determination results.

[0038] For example, a plot of the calculated first index against the measurement time can be output to an output device during measurement, or a plot of the calculated second index against the measurement time can be output to an output device during measurement. Specifically, a graph such as that shown in Figure 10 or 11 (described later) can be displayed on the display. This allows the user to check information about the termination of the measurement from the display during measurement.

[0039] The measurement control unit 215 controls the operation of the X-ray analysis apparatus 100. The controlled operations include sending out the sample, generating X-rays, and moving the sample position and detector. Control instructions are sent to the control unit 140 in the X-ray analysis apparatus 100, which controls each part of the X-ray analysis apparatus 100.

[0040] The measurement data storage unit 217 stores, as measurement data, the scattering image detected by the X-ray analysis apparatus 100. The stored measurement data is used for conversion into a scattering profile, generation of analysis data, and the like.

[0041] The data conversion unit 223 converts the measurement data into a scattering profile. Specifically, the scattering profile is calculated by integrating the intensity along the circumferential direction (β direction) around the center of the scattering image. In this way, the data conversion unit 223 converts the sample solution data and reference solution data acquired from the X-ray analysis device into profiles at each time. The data conversion unit 223 also calculates the standard deviation of the intensity in the β direction for a certain wavenumber q.

[0042] The differential profile generator 225 generates a differential profile between the sample solution data and the reference solution data at each time point. Specifically, the differential profile is generated by subtracting the scattering profile of the reference solution from the scattering profile of the sample solution based on the measurement data of the consecutive reference and sample solutions.

[0043] The first index calculation unit 232 calculates a first index representing the intensity fluctuation in the time axis direction based on at least one solution profile of the converted profiles. That is, the calculation is based on at least one solution data of the reference solution data and the sample solution data. For example, the first index can be calculated for the difference profile between the profile of the sample solution data and the profile of the reference solution. The accuracy of the difference depends on the accuracy of the objects of each subtraction and is therefore not easily estimated. It is efficient to calculate the judgment index using the difference profile required for analysis.

[0044] The first index is preferably, for example, σt(I / σ). The calculation procedure for σt(I / σ) will be described in detail later. Alternatively, the radius of gyration Rg, the origin scattering intensity I(0), etc. may be used as the first index. By calculating a Guinier plot for the target profile, Rg can be calculated from the slope and I(0) can be calculated from the intercept. For calculating the first index, it is preferable to use a profile on the high-angle side corresponding to the MAXS region described later. This makes it possible to confirm that there are no abnormalities in the measurement and that data that can be used for analysis has been secured.

[0045] The first index determination unit 234 determines whether the calculated first index is within a predetermined range. This makes it possible to confirm that there are no changes that would make it impossible to continue the measurement, such as sample breakage. For example, as the sample breaks down, it may aggregate to form clumps. In this case, the intensity of X-rays near the origin due to solution scattering depends on the molecular weight, so the scattering intensity of the aggregates increases and I / σ increases. Terminating the measurement when such a change occurs enables efficient measurement. The predetermined range can be empirically determined, for example, from data accumulated for the target sample solution. For example, if the first index is Rg, a change in Rg of 1 can be considered a significant size change, so the predetermined range can be set to a range where the change in Rg is within ±0.5.

[0046] The second index calculation unit 243 calculates a second index representing the ratio of the intensity data to the intensity fluctuation in the scattering angle direction based on at least one of the solution data profiles obtained from the converted profiles. The second index is preferably calculated using the differential profile or the sample solution data profile. The second index is preferably, for example, I / σ. The calculation procedure for I / σ will be described in detail below.

[0047] The second index determination unit 247 determines whether the calculated second index is on an increasing trend. This makes it possible to confirm whether the second index corresponding to the S / N ratio is on an increasing trend. The determination of whether there is an increasing trend can be performed, for example, by determining whether the second index calculated each time a difference profile is generated (every 2t) is greater than the second index calculated previously. The comparison time interval may be every 4t to account for error. For example, when the second index is I / σ, whether there is an increasing trend in the second index can be determined by whether the value of the MAXS region of the initial difference profile is on an increasing trend. The MAXS region can be set to a region where q is between 0.5 and 0.6. If there is no increasing trend, further measurements will not improve the S / N ratio, so the measurement is terminated, enabling efficient measurement.

[0048] The second index determination unit 247 determines whether the calculated second index is equal to or greater than a threshold value, thereby making it possible to confirm that the S / N ratio has been improved to an extent that the objective can be achieved, thereby enabling efficient measurement.

[0049] The measurement time determination unit 255 determines whether the measurement time exceeds a predetermined value. This allows the measurement to be performed efficiently by terminating the measurement if the measurement time is abnormally long.

[0050] The device control unit 268 starts measurement in response to a start instruction. Specifically, it controls the operation of the X-ray analysis device 100, irradiating the solution with X-rays, detecting the scattered X-rays with the detector 130, and transmitting a scattered image. It also alternates between the reference solution and the sample solution to which X-rays are irradiated at predetermined time intervals. The device control unit 268 also performs termination processing for the measurement by the X-ray analysis device when the first index is not within a predetermined range, the second index is not showing an increasing trend, the second index is equal to or greater than a threshold, or the measurement time exceeds a predetermined value.

[0051] The analytical data generating unit 272 adjusts the scale so that the average values ​​of the sample solution data and the reference solution data match before subtraction within the wide-angle range of the scattering vector, thereby enabling accurate analytical data to be generated even within a wide-angle range.

[0052] [Control Method] A method for controlling an X-ray analysis apparatus using the control system 10 configured as described above will be described below. However, details of the acquisition of a scattering image and the calculation of indices will be described later. Fig. 4 is a flowchart showing the operation of the control device 200. First, the X-ray analysis apparatus 100 sets measurement conditions based on information input by the user (step S1).

[0053] Upon receiving a command to start measurement input by the user, the X-ray analysis apparatus 100 starts measurement (step S2). The X-ray analysis apparatus 100 sends the reference solution to a predetermined position, irradiates X-rays, and acquires scattering data using a detector (step S3). Next, scattering data for the sample solution is acquired in the same manner (step S4). The scattering data is handled as measurement data in units of scattering image data for each predetermined time t. The X-ray analysis apparatus transmits the acquired scattering image data to the computer 210 as measurement data.

[0054] The computer 210 stores the received measurement data and converts the measurement data into a scattering profile (step S5). Details of the data conversion will be described later. The scattering profile of the reference solution is subtracted from the obtained scattering profile of the sample solution to generate a difference profile (step S6). In generating the difference profile, the difference between the measurement data is calculated in units of a predetermined time t.

[0055] Based on the obtained subtraction profile, the computer 210 extracts parameters such as wavenumber q, intensity I, and intensity standard deviation σ (step S7). Then, σt(I / σ) is calculated as a first index representing the intensity fluctuation along the time axis (step S8). It is determined whether the calculated first index is within a predetermined range (step S9), and if not, measurement termination processing is performed (step S10). The measurement time can be divided into predetermined time intervals and expressed as tm = t1, t2, t3, ... as described below.

[0056] On the other hand, if the first index is within the predetermined range, an integrated profile is generated (step S11). The integrated profile is data obtained by integrating differential profiles from the start of measurement to the present time. Using the obtained integrated profile, I / σ is calculated as a second index representing the ratio of intensity data to intensity fluctuations in the scattering angle direction (step S12). It is determined whether the second index is increasing (step S13). If it is not increasing, the process proceeds to step S10, where measurement termination processing is performed.

[0057] If the second index is on an increasing trend, it is determined whether the second index is equal to or greater than a threshold value (step S14). If the second index is equal to or greater than the threshold value, measurement termination processing is performed (step S15), and analysis data is generated (step S16).

[0058] If the second index is not equal to or greater than the threshold, it is determined whether the measurement time exceeds a predetermined value (step S17). If the measurement time does not exceed the predetermined value, the process returns to step S3 and continues the measurement. If the measurement time exceeds the predetermined value, the process proceeds to step S10 and performs measurement termination processing. Details of each process are described below.

[0059] (Acquisition of Scattered Images) Figure 5 is a schematic diagram showing the process up to acquisition of a scattered image. The reference solution and the sample solution are alternately irradiated with X-rays, and the detected scattered images are acquired at predetermined time intervals t. The sample loading mechanism switches the sample holding tubes 125, enabling alternate irradiation of each solution.

[0060] (Data Conversion) Figures 6(a) to 6(c) show a scattering image, a β-direction profile, and a q-direction profile, respectively. When a solution is irradiated with X-rays, a scattering image such as that shown in Figure 6(a) is obtained. When the intensity I in this scattering image is plotted in the circumferential direction (β-direction) around the center at a given wave number q, a graph such as that shown in Figure 6(b) is obtained. Furthermore, when the intensity I in the β-direction of the scattering image is integrated and the integrated intensity I for each wave number q is plotted, a scattering profile such as that shown in Figure 6(c) is obtained.

[0061] (Generation of a difference profile) Figures 7(a) to (c) are diagrams showing the q-direction profile for each acquisition of a scattering image, the acquisition of measurement data at each time, and the generation of a difference profile. As shown in Figures 7(a) to (c), in the measurement, the scattering images obtained for the reference solution and the sample solution at each predetermined time t are used to convert them into scattering profiles that indicate intensity versus wavenumber q (a function of the scattering angle θ). A difference profile is then generated by subtracting consecutive scattering profiles. When subtracting, the same scale value, such as 1.0, may be used each time, or a predetermined constant adjustment may be performed.

[0062] (Calculation of Index) By accumulating the difference profiles obtained at each time, data on the intensity Xi = Ii / σ at a predetermined wave number qi can be obtained. FIG. 8 is a graph showing the X-ray intensity at a predetermined wave number versus measurement time. In this way, parameters can be extracted based on the measurement data. Then, an index can be calculated from this parameter, and it can be determined whether or not to continue the measurement.

[0063] (Determination by Index) FIG. 9 is a diagram showing a table of extracted parameters. As shown in FIG. 9, a first index can be calculated by extracting the wave number q, intensity I, and standard deviation σ. The first index is an index that represents the fluctuation of intensity in the time axis direction, and is, for example, σt(I / σ). σt(I / σ) can be calculated by the following formula (1). The parameters used for this first index are calculated using parameters extracted from the initial measurement and the most recent measurement.

[0064]

[0065] It is determined whether the calculated σt(I / σ) is within a predetermined range. FIG. 10 is a graph showing an example of the transition of σt(I / σ). As shown in FIG. 10, σt(I / σ) up to t3 is within the predetermined range, but σt(I / σ) at t4 is outside the predetermined range. In such a case, it can be considered that there is no longer any prospect of obtaining sufficient analytical data for structural analysis at the time t4, and therefore measurement is terminated.

[0066] The second index is an index representing the ratio of intensity data to intensity fluctuations in the scattering angle direction, for example, I / σ. The second index is an index equivalent to the S / N ratio. The second index can be calculated by using an integrated profile obtained by integrating differential profiles from the start of measurement to the present time. FIG. 11 is a graph showing an example of the progression of I / σ. In the example shown in FIG. 11, I / σ tends to increase up to u4, and the S / N is improved, so it is determined that the measurement should be continued. On the other hand, since I / σ exceeds the predetermined value at u4, it is determined that sufficient measurement data has been acquired for structural analysis, and the measurement is terminated.

[0067] (Generation of Analysis Data) When sufficient measurement data has been obtained, the control device 200 generates analysis data. The analysis data is obtained by subtracting an intensity profile obtained by integrating the measurement data of the reference solution from an intensity profile obtained by integrating the measurement data of the sample solution over the entire measurement time.

[0068] In this case, in order to properly process the wide-angle data used for structural analysis of 30 Å or less, it is necessary to adjust the relative scale of the sample solution data and the reference solution data before subtracting them.

[0069] When adjusting the relative scales of the sample solution data and the reference solution data, it is preferable to adjust them so that their average values ​​match, for example, in the wide-angle range of the scattering vector. However, this is not necessarily limited to the above range, and any range that is not affected by the scattering data from the sample will suffice. This allows accurate analysis data to be generated even in a wide-angle range.

[0070] The obtained analytical data can be used for structural analysis as a measured X-ray scattering profile. The volume of a cubic particle in real space is represented by cubic voxels discretized into an NxNxN grid, and an electron density map can be calculated by searching for structure factors based on the measured X-ray scattering profile.

[0071] Specifically, multiple structural models are generated from the measured X-ray scattering profile, and a calculated X-ray scattering profile is calculated from each of the multiple structural models. An index representing the degree of agreement between the calculated calculated X-ray scattering profile and the measured X-ray scattering profile is calculated, and a representative structural model is selected from the multiple structural models based on the calculated index. In this way, a structural model of a polymer in solution that has a structure with dynamic fluctuations can be accurately reproduced.

[0072] [Second Embodiment] In the above embodiment, the first index and the second index are calculated using a differential profile, but either the first index or the second index may be calculated using a profile of one of the solution data. In that case, it is preferable to first obtain a profile of the solution data using a reference solution, calculate and evaluate the first index and the second index, and then obtain a profile of the solution data using a sample solution, calculate and evaluate the first index and the second index, respectively.

[0073] Fig. 12 is a flowchart showing the operation of the control device 200. Unlike the example shown in Fig. 4, the example shown in Fig. 12 does not use a differential profile to calculate each index. First, the X-ray analysis device 100 sets measurement conditions based on information input by the user (step T1).

[0074] Upon receiving a command to start measurement input by the user, the X-ray analysis apparatus 100 starts measurement (step T2). The X-ray analysis apparatus 100 sends the reference solution to a predetermined position, irradiates X-rays, and acquires scattering data using a detector (step T3). The scattering data is handled as measurement data in units of scattering image data for each predetermined time t. The X-ray analysis apparatus transmits the acquired scattering image data to the computer 210 as measurement data. The computer 210 stores the received measurement data and converts the measurement data into a scattering profile (step T4). Details of the data conversion will be described later.

[0075] The computer 210 extracts parameters such as wavenumber q, intensity I, and intensity standard deviation σ based on the profile of the reference solution data (step T5). Then, it calculates σt(I / σ) as a first index representing the intensity fluctuation along the time axis (step T6). It determines whether the calculated first index is within a predetermined range (step T7). If it is not within the predetermined range, it performs a measurement termination process (step T8).

[0076] On the other hand, if the first index is within the predetermined range, an integrated profile of the reference solution data is generated (step T9). The integrated profile is data obtained by integrating the profiles from the start of measurement to the present time.

[0077] Using the integrated profile of the scattering data of the reference solution thus generated, I / σ is calculated as a second index representing the ratio of the intensity data to the intensity fluctuation in the scattering angle direction (step T10). It is determined whether the second index is increasing (step T11). If it is not increasing, the process proceeds to step T8, where measurement termination processing is performed.

[0078] If the second index is on an increasing trend, it is determined whether the second index is equal to or greater than a threshold value (step T12). If the second index is equal to or greater than the threshold value, measurement termination processing is performed and an integrated profile of the reference solution data is calculated (step T13).

[0079] If the second index is not equal to or greater than the threshold, it is determined whether the measurement time exceeds a predetermined value (step T14). If the measurement time does not exceed the predetermined value, the process returns to step T3 and continues the measurement. If the measurement time exceeds the predetermined value, the process proceeds to step T8 and performs measurement termination processing.

[0080] Next, the sample solution is subjected to measurement, data acquisition, and processing in the same manner as in steps T3 to T14 (step T15). If the measurement is not complete, an integrated profile of the sample solution data is calculated (step T16). Then, the integrated profile of the reference solution data is subtracted from the integrated profile of the sample solution data to generate data for analysis (step T17). If the measurement is complete, proceed to step T8.

[0081] When calculating the first and second indices, it is preferable to start with measurements using a standard solution and first use the profile of the standard solution data. X-ray irradiation of biopolymers in solution is prone to damage. Furthermore, such samples are valuable and require a long time to prepare. On the other hand, standard solutions are not so valuable and can be used that do not deteriorate even when exposed to X-rays. Efficient measurements are possible by calculating the first and second indices from sufficient standard solution data to obtain an ideal profile, and then acquiring as much sample solution data as necessary.

[0082] When generating analytical data by subtracting the integrated profile of the reference solution data from the integrated profile of the sample solution data, the second indices of both data must be at the same level, as described above. If the second indices are not equal, the quality of the generated analytical data will be reduced to the level of the second indices with the lower value.

[0083] [Various embodiments] Including the above example, there are four methods for acquiring solution data, and an appropriate method can be selected depending on the situation: (1) A method of simultaneously acquiring reference solution data and sample solution data (2) A method of acquiring reference solution data and then acquiring sample solution data (3) A method of alternately repeating the acquisition of reference solution data and sample solution data (4) A method of acquiring sample solution data and then acquiring reference solution data

[0084] Of these, simultaneous acquisition is ideal. Simultaneous acquisition allows for the calculation of differential profiles of measurement data at predetermined time intervals t. To achieve simultaneous acquisition, a special device is required to acquire data simultaneously.

[0085] A method (second embodiment) in which sample solution data is acquired after reference solution data is acquired is also preferable. In this case, if there is an abnormality in the device, it can be recognized and the measurement can be terminated without damaging the sample.

[0086] The method of alternately acquiring reference solution data and sample solution data (first embodiment) is also effective. In this case, each index is calculated using a differential profile, and it can be determined whether or not to continue the measurement.

[0087] [Example] As an example, measurements were carried out using a biopolymer sample (human serum albumin (HSA)) in solution. Figures 13(a) to 13(c) are schematic diagrams showing a graph plotting σt(I / σ), a graph plotting I / σ, and a visualized structural model of the example, respectively.

[0088] First, as shown in Figure 13(a), in this example, σt(I / σ) was calculated and plotted as a first index representing the intensity fluctuation in the time axis direction. σt(I / σ) was within the range of 0.0 + 0.1 and showed a nearly constant value up to 3600 s. Then, as shown in Figure 13(b), in this example, I / σ was calculated and plotted as a second index representing the ratio of the intensity data to the intensity fluctuation in the scattering angle direction.

[0089] Furthermore, as shown in Figure 13(c), a structural model was created based on the analytical data that passed the first and second index judgments. The arrows at the top right and bottom of the structural model indicate that the protein body protrudes. It was possible to confirm that the α-helix bundle involved in binding with the compound is located in this protruding region. It was also confirmed that significant data was obtained to identify the structure of polymers in solution at 30 Å or less.

[0090] Note that this application claims priority based on Japanese Patent Application No. 2022-039104 filed on March 14, 2022, and the entire contents of Japanese Patent Application No. 2022-039104 are incorporated by reference into this application.

[0091] 10 Control system 100 X-ray analysis apparatus 110 X-ray generation section 111 X-ray source 115 Optical system 117 Kratsky block 120 Sample loading mechanism 125 Sample holding tube 130 Detector 140 Control unit 200 Control device 210 Computer 211 Input / output control section 215 Measurement control section 217 Measurement data storage section 223 Data conversion section 225 Difference profile generation section 255 Measurement time determination section 268 Device control section 272 Analysis data generation section 280 Input device 290 Output device L Control bus S0 Sample

Claims

1. A control device for controlling an X-ray analysis device, a data conversion unit that converts the sample solution data and the reference solution data acquired from the X-ray analysis device into profiles at each time; a first index calculation unit that calculates a first index representing a fluctuation in intensity in a time axis direction based on at least one of the converted profiles of solution data; a first index determination unit that determines whether the calculated first index is within a predetermined range; and an apparatus control unit that terminates measurement by the X-ray analysis apparatus when the first index is not within a predetermined range.

2. 2. The control device according to claim 1, wherein the first index calculation unit calculates the first index for a differential profile between a profile of the sample solution and a profile of the reference solution.

3. 2. The control device according to claim 1, wherein the first index calculation unit calculates the first index for a profile of the reference solution.

4. a second index calculation unit that calculates a second index representing a ratio of intensity data to intensity fluctuation in a scattering angle direction based on an integrated profile of at least one of the solution data obtained from the converted profile; A second index determination unit that determines whether the calculated second index is on an increasing trend, 4. The control device according to claim 1, wherein the device control unit terminates the measurement by the X-ray analysis device when the calculated second index is not showing an increasing trend.

5. 5. The control device according to claim 4, wherein the second index calculation unit calculates the second index for a differential profile between a profile of the sample solution and a profile of the reference solution.

6. 5. The control device according to claim 4, wherein the second index calculation unit calculates the second index for a profile of the sample solution.

7. The second index determination unit determines whether the calculated second index is equal to or greater than a threshold value; 7. The control device according to claim 4, wherein the device control unit terminates the measurement by the X-ray analysis device when the calculated second index is equal to or greater than a threshold value.

8. A measurement time determination unit is further provided to determine whether or not the measurement time exceeds a predetermined value, 8. The control device according to claim 1, wherein the device control unit terminates the measurement by the X-ray analysis device when the measurement time exceeds the predetermined value.

9. 9. The control device according to claim 1, further comprising an analysis data generation unit that adjusts the scale so that the average values ​​of the sample solution data and the reference solution data match before subtraction in the wide-angle range of the scattering vector.

10. 10. The control device according to claim 1, further comprising an input / output control unit that outputs a plot of the calculated first index against time to an output device during measurement.

11. 11. The control device according to claim 1, further comprising an input / output control unit that outputs a plot of the calculated second index against time to an output device during measurement.

12. 1. A system for performing X-ray analysis, comprising: an X-ray analysis device that irradiates a sample with X-rays and detects a scattering image; A control device according to any one of claims 1 to 11, which controls the X-ray analysis device; A system comprising:

13. 1. A method for controlling an X-ray analysis apparatus, comprising: converting the sample solution data and the reference solution data acquired from the X-ray analysis device into a profile at each time; calculating a first index representing a fluctuation in intensity in a time axis direction based on at least one of the converted profiles of solution data; determining whether the calculated first index is within a predetermined range; and performing a process of terminating the measurement by the X-ray analysis device if the first indicator is not within a predetermined range.

14. A program for controlling an X-ray analysis apparatus, A process of converting the sample solution data and the reference solution data obtained from the X-ray analysis device into a profile at each time; A process of calculating a first index representing a fluctuation in intensity in a time axis direction based on at least one of the converted profiles of the solution data; A process of determining whether the calculated first index is within a predetermined range; and if the first index is not within a predetermined range, terminating the measurement by the X-ray analysis apparatus.