98 results about "Oxidizing acid" patented technology

The invention relates to a preparation method of a nanofiltration membrane, the nanofiltration membrane prepared by the preparation method and application of the nanofiltration membrane. The method comprises the following steps: preparing a membrane casting solution, curing the membrane casting solution on a support material to form a base membrane, and the membrane casting solution comprises a polymer and a solvent; the base membrane is in contact with a first phase solution and a second phase solution in sequence, the first phase solution comprises a first phase monomer, an adsorbent A, an active agent B and an acid-binding agent C, and the second phase solution comprises a second phase monomer and a cross-linking agent D; and post-processing. The nanofiltration membrane disclosed by the invention has excellent tolerance to high-concentration strong oxidizing acid or mixed acid, still keeps high flux and high salt rejection rate even after being soaked in the high-concentration strong oxidizing acid or mixed acid for a long time, can stably operate for a long time under high pressure, and has high flux and high salt rejection rate at the same time; the method can be effectively applied to the fields of waste acid treatment in the titanium dioxide production process, extraction and separation of lithium battery raw materials, mineral product smelting metal ion and acid recovery and the like for filtration and / or separation.

The invention discloses a method for recovering nearly all elements in low-precious-metal zinc replacement powder, which belongs to the technical field of non-ferrous metal wet smelting, and comprises the following steps: preparing zinc replacement powder, oxidizing and leaching, extracting copper, preparing cuprous chloride, electrodepositing zinc in raffinate, extracting precious metal by using a gold extracting agent, extracting, reducing and smelting to prepare a gold ingot and a silver ingot, and dissolving by using sodium hydroxide. Preparing lead carbonate; carrying out oxidation acid leaching; replacing; and smelting bismuth. According to the technology for achieving recovery and high-value utilization of nearly all elements in the zinc replacement powder under the mild condition, the technology can be carried out at the normal temperature, the high-pressure condition does not need to be provided, the zinc replacement powder is leached through the acid solution, then various valuable metals are selectively extracted from the leaching solution, corresponding downstream products are prepared, and the method is suitable for industrial production. The method realizes value maximization, does not generate secondary pollution, does not introduce fluorine, has low requirements on equipment, is simple in process and easy to operate, and makes up for the defects of the zinc replacement powder treatment process in the prior art.

A process for preparing an olefin stream for oligomerization comprises fractionating an olefin stream to provide a light gas stream and an olefin rich stream. Oxygenates are absorbed from the olefin rich stream into a water wash stream to provide an oxygenate rich water wash stream and a washed olefin stream. The washed olefin stream can then be oligomerized.

The invention discloses a method for recovering platinum and palladium from high-cobalt nickel-containing carbonylation slag, and relates to the technical field of non-ferrous metal carbonylation metallurgy, the method comprises the following steps: S1, hydrogen reduction and activation; s2, feeding into a high-pressure carbonylation reactor; and S3, efficient carbonylation. According to the method, the carbonylation slag is subjected to hydrogen reduction activation treatment, nickel protoxide and cobalt oxide are changed into simple substance nickel, the simple substance nickel is fed into a carbonylation reactor for carbonylation under the protection of reducing gas or inert gas after activation treatment, 95% of Ni, 85% of Fe and 80% of Co are carbonylated to enter a gas phase after carbonylation, bonding of cobalt and a platinum solid solution is broken through carbonylation, and the nickel-cobalt-cobalt-cobalt-cobalt alloy is obtained. Nickel protoxide is difficult to dissolve in various strong acids and oxidizing acids, and a foundation is laid for further separation of base metals and non-metallic element sulfur from precious metals to produce high-grade platinum concentrate.

The invention discloses a method for separating and recovering selenium and mercury from acid mud containing selenium and mercury. The method comprises the following steps: mixing the acid mud containing selenium and mercury with water, performing wet ball milling, filtering and drying to obtain a ball milling material; adding a hydrogen peroxide solution into the ball-milled material, adding hydrochloric acid to adjust the acidity, carrying out oxidation acid leaching, and carrying out solid-liquid separation to obtain selenium-containing mercury liquid and selenium-removed mercury slag; adding thiourea into the selenium-containing mercury liquid for selective reduction, and performing solid-liquid separation to obtain crude selenium and reduction liquid; zinc powder is added into the reduction liquid for mercury replacement and precipitation, and crude mercury and precipitation liquid are obtained after solid-liquid separation; wherein the selenium-removed mercury slag and the precipitation solution are subjected to centralized treatment. The method is simple in process, convenient to operate and easy to process, selenium and mercury in the acid mud containing selenium and mercury can be removed at a time, efficient separation and recovery of selenium and mercury in the acid mud containing selenium and mercury are achieved, harmless treatment of hazardous waste and effective utilization of resources are achieved, and the method conforms to the concept of green sustainable development.

The invention provides a preparation method of a dication positive electrode material. The preparation method comprises the following steps: preparing a conductive polymer monomer and a heteropoly acid aqueous solution; carrying out electrolysis on the heteropolyacid aqueous solution; after electrolysis, Li2CO3 and Na2CO3 are added, and after the reaction is completed, separated-out heteropoly blue lithium sodium crystals are separated; adding the crystals into a conductive polymer monomer aqueous solution to obtain a mixture; dropwise adding an excessive strong oxidizing acid dilute solution into the mixture, and reacting at 140-180 DEG C for 16-24 hours; and repeatedly washing the separated solid substance after the hydrothermal reaction with deionized water, and drying to obtain the dicationic positive electrode material. The form of the heteropoly blue lithium sodium still keeps the skeleton structure of heteropoly acid radical anions, and the skeleton structure can ensure that lithium ions and sodium ions can be transmitted in the skeleton of the heteropoly blue lithium sodium; and the conductive polymer prepared by the method is of a porous structure, and sodium ions with large radius can be transmitted through pores of the conductive polymer, so that the ionic conductivity of the heteropoly blue lithium sodium can be improved to a certain extent.

The invention provides a preparation method and application of a cellulose-based hard carbon negative electrode material, and belongs to the technical field of sodium ion battery negative electrode material preparation. Comprising the following steps: preparing a strong oxidizing acid solution, adding a cellulose raw material into the prepared solution, carrying out ultrasonic vibration, and uniformly stirring; then adding a long-chain molecular compound into the mixture, and stirring until the mixture is uniformly mixed to obtain a mixed solution; then transferring into a hydrothermal reaction kettle for hydrothermal treatment, and after the hydrothermal reaction kettle is cooled to room temperature, centrifuging, washing and drying a hydrothermal product; and finally, transferring the hydrothermal product into a high-temperature tubular furnace, and performing high-temperature pyrolysis carbonization treatment in an inert atmosphere to obtain the cellulose-based hard carbon negative electrode material. A hard carbon precursor containing a large amount of carbonyl and nitrogen doping is constructed through a hydrolysis competition mechanism, then the hard carbon negative electrode material is prepared through high-temperature pyrolysis carbonization, and the problems of low reversible capacity of biomass derived hard carbon, poor first-week coulombic efficiency, battery performance optimization under extremely high and low temperature conditions and the like are solved.

Disclosed herein are methods for preparing fluorided solid oxides by contacting an acidic fluorine-containing compound with an inorganic base to form an aqueous mixture having a pH of at least 4, followed by contacting a solid oxide with the aqueous mixture to produce the fluorided solid oxide. Also disclosed are methods for preparing fluorided solid oxides by contacting an acidic fluorine-containing compound with a solid oxide to produce a mixture, followed by contacting the mixture with a inorganic base to produce the fluorided solid oxide at a pH of at least about 4. The fluorided solid oxide can be used as an activator component in a catalyst system for the polymerization of olefins.

The invention relates to a digestion method for lithium sulfide impurity element analysis and a content determination method thereof, the digestion method comprises the following steps: (A1) pre-digestion: weighing a lithium sulfide sample, and adding ultrapure water to obtain a sample aqueous solution; dropwise adding oxidizing acid into the sample aqueous solution, and heating to enable the lithium sulfide sample in the sample aqueous solution to fully react, so as to obtain a pre-digested sample; (A2) microwave digestion: carrying out microwave digestion on the pre-digested sample under a closed condition to obtain a microwave digested sample, and fixing the volume to obtain a to-be-detected sample solution. Compared with a conventional multi-time acid-adding digestion method, the digestion method has the advantages that oxidizing acid does not need to be added repeatedly, so that the operation steps are simple, the digestion time is short, and compared with the multi-time acid-adding digestion method, the method can meet quantitative analysis of most impurity elements in lithium sulfide.

The invention provides a method for recovering rare earth elements in neodymium iron boron waste, which comprises the following steps: S1, adding the neodymium iron boron waste into an oxidation acid solution to obtain an oxidation acid leaching solution; s2, alkali is added into the oxidized pickle liquor to adjust the pH value, then a composite extraction agent is used for extraction treatment, and liquid separation is conducted to obtain raffinate and a loaded organic phase; s3, carrying out first back extraction treatment on the loaded organic phase by using a first hydrochloric acid solution; s4, carrying out second back extraction treatment on the first back extraction raffinate by using a second hydrochloric acid solution; s5, carrying out third back extraction treatment on the second back extraction raffinate by using a third hydrochloric acid solution; wherein the concentration c1 of the first hydrochloric acid solution, the concentration c2 of the second hydrochloric acid solution and the concentration c3 of the third hydrochloric acid solution meet the following condition: c1 < c2 < c3. The rare earth element-containing strip liquor obtained by the method is low in impurity content and can be used for preparing rare earth oxide with relatively high purity.

The invention relates to a method for regulating and deacidifying in a bioleaching process of low-grade copper sulphide ore, aiming at the problem of excessive acid caused by excessive oxidation of pyrite in a dump leaching system, a thiocyanate bactericide is added into the bioleaching system of the low-grade copper sulphide ore, and the thiocyanate bactericide is dissolved in a spray liquid of the bioleaching system, and is added into the spray liquid of the bioleaching system; under the catalytic action of mineral leaching microorganisms, oxidation of ferrous ions is enhanced, so that the oxidation-reduction potential of a solution is increased, oxidation of pyrite is intensified, acid accumulation is excessive, the thiocyanate bactericide can remarkably inhibit the activity of part of sulfur-oxidizing bacteria and even kill part of sulfur-oxidizing bacteria, and therefore the activity of ferrous oxide is reduced; compared with the prior art, the method has the advantages that the sulfur oxidation activity of microorganisms is greatly influenced, but the oxidation influence on iron is relatively small, so that the acid leaching is reduced under the condition that the copper leaching of the copper sulfide ore is not influenced, the copper leaching is not influenced, the acid leaching is reduced, the production cost is reduced, the environmental influence is reduced, and the like.

The present application specifically relates to the technical field of solid waste treatment. Disclosed is a method for preparing baking soda by using desulfurized fly ash. The method comprises: dissolution, coagulation-defluorination coupled precipitation defluorination, oxidative acidification, cooling crystallization, preparation of baking soda from sodium sulfate, reverse precipitation and preparation of baking soda from sodium chloride. In the present application, the industrial desulfurized fly ash is prepared into baking soda having a high added value by using an effective process, and the baking soda is reused in a desulfurization process, thereby achieving resource recycling of the industrial desulfurized fly ash. In addition, impurity ion COD, sulfite, carbonate, bicarbonate and fluorine ions, etc., in the desulfurized fly ash are comprehensively removed; and compared with a traditional process, the recycled baking soda has a higher purity and a higher recovery rate by means of process innovation.

The invention relates to a method and a system for producing an oxidant solution, comprising an electrochemical cell having an anode and a cathode, the method comprising the steps of: (i) supplying a raw electrolyte to a reaction region between the anode and the cathode, the raw electrolyte consisting of sulfate ions (SO42-) and ferrous ions (Fe2 +); (ii) during a run cycle, electrolyzing the feedstock electrolyte to produce an oxidized acid solution comprising peroxydisulfate (S2O8 < 2->) and iron ions (Fe < 3 + >); and (iii) supplying the oxidized acid solution. The oxidant solution is preferably used to leach metals from wastes including electronic wastes and metal-containing ores.

The invention relates to the technical field of metal cleaning aids, and discloses an efficient decontamination acidic metal cleaning agent which comprises the following components in percentage by weight: 12-28% of non-oxidizing acid, 1.5-6% of a corrosion inhibitor, 4-12% of a surfactant, 0.8-3% of a complexing agent, 1.5-5% of a solubilizer, 2-8% of an organic solvent, 3-10% of a pH regulator, 0.1-0.6% of a defoaming agent, 0.2-1.2% of an antirust agent and the balance of deionized water. Through synergistic compounding of organic acid and inorganic acid and combination of a ternary corrosion inhibition system of benzotriazole, mercaptobenzothiazole and imidazoline derivatives, the decontamination efficiency and metal compatibility are remarkably improved, the synergistic effect of citric acid and sulfuric acid enables the corrosion rate of carbon steel to be reduced, meanwhile, the rust-proof time of a copper sheet is prolonged to 72 hours or above, and the rust-proof effect of the copper sheet is improved. The effect is derived from complementation of chelation of organic acid and strong solubility of inorganic acid and directional protection of the corrosion inhibition component on the multi-metal surface.

A method of processing a diamond to obtain vacancy-based defects and vacancy-based clusters includes the steps of: providing an artificial single-crystal diamond with {001} faces, the artificial single-crystal diamond having a substitutional nitrogen concentration above or equal to 100 parts per million; conditioning surfaces of the diamond by boiling under reflux of a solution comprising nitric, sulphuric, and an oxidizing acid, such as perchloric acid or hydrogen chloride; irradiating the diamond with neutrons; conditioning the surfaces of the diamond at a temperature above or at least 100° C., under a constant gas flow with a pressure above or equal to atmosphere pressure, such as at least 1 bar; annealing the diamond, thereby obtaining a diamond with vacancy-based defects and vacancy-based clusters. A system for processing a diamond utilizes the method.

To provide a microalgae growth promoter.SOLUTION: A microalgae growth promoter contains at least one compound selected from (1) oxo fatty acid or a derivative thereof or a salt thereof or (2) a hydroxylated fatty acid or a derivative thereof or a salt thereof.SELECTED DRAWING: None

The invention discloses a preparation method and application of a graphene composite lubricant, graphite, a strong oxidizing acid and a strong oxidant are mixed for oxidation reaction, after the reaction is completed, a reducing agent is added to terminate the oxidation reaction, the pH value of the solution is adjusted to be alkaline, then a metal oxide catalyst is added, oxygen-containing gas is blown in at the same time, and a composite material is obtained after the reaction. And cleaning the obtained composite material, and drying at high temperature to obtain the solid powder composite lubricant. The metal oxide catalyst is introduced in the preparation process, so that the reaction efficiency is improved, and the manganous-manganic oxide / graphene composite material with a more stable structure is formed.

This invention discloses a method for purifying single-walled carbon nanotubes (SHU). The purification method includes the following steps: mixing crude SHU with a non-oxidizing acid solution in a reaction vessel; introducing gas into the reaction vessel; heating the reaction; and separating the solid and liquid phases to obtain the final product. This invention uses a non-oxidizing acid and gas bubbles to synergistically purify SHU, ensuring effective removal of metallic impurities and amorphous carbon while protecting the SHU from structural damage.

The present invention relates to a method and system for producing an oxidant solution, comprising an electrochemical cell having an anode and a cathode. The method includes the steps of: (i) supplying a feed electrolyte to a reaction zone between the anode and the cathode, wherein the feed electrolyte contains sulfate ions (SO4 2- ) and divalent iron ions (Fe 2+ ) and (ii) in the operation cycle, the raw electrolyte is electrolyzed to produce peroxodisulfate (SO) 2- ) and trivalent iron ions (Fe 3+ and (iii) providing the oxidizing acid solution. The oxidizer solution is preferably used to leach metals from waste materials, including e-waste, and metal-bearing ores.

Methods and systems for removing an acid gas from a flue gas stream are disclosed. The flue gas stream, consisting of an acid gas and an oxidant, are injected into a water scrubber, where they react to oxidize the acid gas, combining with water to form an acidic water stream, which is passed out of the water scrubber while the stripped flue gas stream is deoxygenated to produce a carbon dioxide product stream. The carbon dioxide product stream is dehydrated and the makeup water recycled. Heat from the deoxygenation trim heats the water stream and creates steam.

The invention discloses a method and a device for pre-treating recycled acid liquor to remove oxalate, and the method comprises the following steps: adding oxalic acid and / or soluble oxalate into acid waste liquor to enable reaction liquor to generate new oxalate precipitate, and then carrying out solid-liquid separation to obtain new oxalate filter residue and acid filtrate; the method is characterized by further comprising the following steps: (1) directly carrying out oxidation reaction on the acidic filtrate or carrying out oxidation reaction after blending for at least 2 hours, so that oxalate C2O4 < 2-> or other organic impurities in the acidic filtrate are partially or completely removed through chemical reaction to obtain oxidized acidic filtrate; and (2) directly feeding the oxidized acidic filtrate or feeding the oxidized acidic filtrate into a corresponding circuit board acidic corrosion production line as a regenerated metal corrosion liquid for recycling. According to the method, the oxalate impurity content index or the oxalate impurity and organic matter impurity index in the acidic filtrate obtained through oxalic acid treatment is reduced after oxidation treatment.

The application discloses a method for reducing acid consumption in copper soot treatment and preparing electroplating-grade copper sulfate, and belongs to the technical field of comprehensive utilization of non-ferrous metal resources. The method comprises five steps of oxidizing acid leaching, cooling crystallization, redissolving and one-stage impurity removal, two-stage impurity removal and copper recovery, and refining and recrystallization. The application effectively inhibits copper arsenate precipitation by constructing a high-acid saturated leaching system, realizes the crystallization separation of copper sulfate and leaching solution, thereby avoiding the traditional neutralization and impurity removal process, and significantly reducing alkali consumption. The synergistic precipitation characteristics of arsenic, antimony and bismuth in a strong acid system are utilized to realize efficient enrichment of valuable metals. Two-stage impurity removal is adopted, and copper-containing residues are returned to leaching to reduce copper loss. Calcium impurities are removed by adding crystal seeds to improve the purity of copper sulfate products. The application has the advantages of low acid and alkali consumption, high copper recovery rate, high product added value, simple process flow, strong recycling, etc., and is suitable for resource utilization of copper smelting soot.

The invention discloses a method for efficiently reducing elemental selenium from selenium-containing leachate based on ferrous sulfate, which comprises the following steps: taking the selenium-containing leachate obtained by oxidation and acid leaching, and adjusting the acidity of the leachate to 0.5-1.1 mol / L; ferrous sulfate is added into the acid-adjusted selenium-containing leachate according to the liquid-solid ratio of 2 mL: (1.0-1.4) g for a reduction reaction, the reduction reaction temperature ranges from 70 DEG C to 90 DEG C, the reduction reaction time ranges from 40 min to 80 min, and a reaction product I is obtained; and separating the precipitate of the reaction product I, washing and drying to obtain the elemental selenium. According to the method disclosed by the invention, the elemental selenium is extracted by reducing the selenium-containing leachate by adopting ferrous sulfate, and the reduction rate of selenium can reach 91% or above under limited conditions; under optimized conditions, the selenium reduction rate can reach 95.87%, which is significantly superior to that of existing processes such as a microbiological method.

Disclosed herein are methods for leaching a material comprising one or more metals in a zero oxidation state and one or more chosen from metal oxides, metal hydroxides, and combinations thereof, wherein the method comprises contacting the material with an oxidizing acidic aqueous solution having a pH less than 6, and subsequently reducing the one or more chosen from metal oxides, metal hydroxides, and combinations thereof with a reducing agent. Also disclosed are methods comprising leaching a material to obtain an aqueous solution comprising metal ions, and separating the metal ions to obtain at least one essentially pure metal ion solution and / or at least one essentially pure solid metal ion salt. Further disclosed are methods comprising mechanically comminuting a material to obtain a black mass, and leaching the black mass.

Methods of making catalytically active metal-triazine treated carbon particles, and the resultant catalytically activated metal-triazine sorbent carbon media. The particles are formed by soaking an activated carbonaceous product in an oxidizing acid solution and exposing the oxidized activated carbon to at least one metal-triazine complex in solution for a time sufficient to form metal-triazine impregnated carbon particles. The impregnated carbon particles are heated in a non-oxidizing atmosphere to render calcined metal-triazine impregnated carbon particles, which are cooled to form catalytically active metal-triazine treated carbon particles that remove chloramines from aqueous solution. The resultant catalytically activated metal-triazine treated carbon particles are formed into filter media and / or blocks for removing at least chloramines from aqueous solution.

The invention relates to the field of waste graphite material recovery, in particular to a waste graphite repair material and a preparation method and application thereof.The preparation method of the waste graphite repair material comprises the steps that waste graphite and a modifier are subjected to thermal modification in an oxygen-containing atmosphere and then subjected to liquid-phase modification treatment in oxidizing acid liquor, and a modified material is obtained; the modifier is a raw material containing chlorine and ammonium; carrying out graphitization treatment on the modified material to obtain a graphitized material; carrying out chemical silver plating treatment on the graphitized material to obtain a silver-plated material; and mixing the silver plating material, the structure modifier and the carbon source, and roasting to obtain the composite material. The material repaired by the method can meet the application requirements of high-surface-load full battery fast charging.

Methods of making graphene oxide and reduced graphene oxide are provided. The methods can include a simple one-pot synthesis of graphene oxide from a purified coal powder using a mild oxidizing acid. The methods provide for an improved, more cost-effective, and simpler process than conventional methods such as Hummers methods. In some aspects, placing the purified coal powder in the mild oxidation atmosphere includes contacting the purified coal powder with a mild oxidizing acid such as nitric acid, nitrous acid, sulfuric acid, phosphoric acid, benzoic acid, or a combination thereof. In some aspects, the mild oxidizing acid consists essentially of nitric acid. Graphene oxides and reduced graphene oxides prepared by the methods are also provided.

The invention belongs to the field of solid waste treatment, and particularly relates to a method for selectively extracting and preparing metal thallium from a thallium-containing material, which comprises the following steps: carrying out reduction alkaline leaching on the thallium-containing material to obtain a Tl < + > alkaline leaching solution; the Tl < + > alkaline leaching solution is subjected to vulcanization precipitation, and Tl2S slag is obtained; the Tl2S slag is subjected to potential-controlled oxidation acid leaching, negative-valence sulfur in the Tl2S slag is selectively oxidized, and Tl < + > acid leaching liquid is obtained; mixing the Tl < + > pickle liquor and a compound additive, and then carrying out rotational flow electrodeposition treatment to obtain metal thallium and a liquid after rotational flow electrodeposition; the cathode material in the rotational flow electrodeposition is an aluminum plate, a copper plate or a titanium plate; the compound additive comprises a component A and a component B, and the component A comprises a Tl liquefying agent; the component B comprises at least one of gallic acid, benzalacetone, benzophenone, bone glue, polyether, FES-993 and quaternary ammonium salt; and the current density of the rotational flow electrodeposition is 50-500A / m < 2 >. According to the synergistic process, high-quality metal thallium can be efficiently recycled.

The utility model relates to the technical field of waste gas treatment equipment, in particular to a deodorization device for catalytic oxidation of acid-base waste gas, which adopts the technical scheme that the deodorization device comprises a shell, a drawer seat and a guide cylinder, an exhaust pipe is fixedly mounted at the top of the shell, and a gas inlet pipe is fixedly mounted at the bottom of the shell; a flow guide cylinder is fixedly installed in the shell, and three sets of ultraviolet lamp rings are installed in the flow guide cylinder at equal intervals. According to the utility model, the mounting seat and the ultrasonic transducer are arranged in the filter cartridge, and the catalyst or the oxidant is promoted to irregularly jump between the isolation net plates by releasing energy obliquely upwards to the catalyst or the oxidant between the isolation net plates, so that the internal gap of the catalyst or the oxidant is enlarged; the waste gas can normally flow between the catalyst or the oxidizing agent and is in contact with the catalyst or the oxidizing agent to generate catalytic oxidation reaction, so that the treatment effect of the device on the waste gas is kept constant.

This invention discloses a method, product, and application for the separation of astatine-211 in an aqueous phase based on valence state regulation. The method includes: passing a solution of astatine-211 containing a strong oxidizing acid through a sulfur-containing solid support, causing specific adsorption of positively valence astatine-211; eluting with a water-soluble reducing agent to reduce astatine-211 to astatine anions, obtaining an aqueous astatine-211 eluent. The entire process is carried out in the aqueous phase, requiring no organic solvents and avoiding radionuclide volatilization loss due to heating and evaporation. This invention also provides an eluent composition obtained by this method, sodium astatide injection, astatine-211-labeled radiotargeting drugs and their preparation methods, as well as the application of this eluent composition in the preparation of drugs for treating NIS-positive diseases. This invention achieves highly selective separation and mild, rapid elution of astatine-211, and the product exhibits excellent biocompatibility and radiation stability, and can be used directly or after simple activation to prepare targeted α-therapy drugs.