Purification Method Research Articles

Getting Hold of the Tobamovirus Particle-Why and How? Purification Routes over Time and a New Customizable Approach.

This article develops a multi-perspective view on motivations and methods for tobamovirus purification through the ages and presents a novel, efficient, easy-to-use approach that can be well-adapted to different species of native and functionalized virions. We survey the various driving forces prompting researchers to enrich tobamoviruses, from the search for the causative agents of mosaic diseases in plants to their increasing recognition as versatile nanocarriers in biomedical and engineering applications. The best practices and rarely applied options for the serial processing steps required for successful isolation of tobamoviruses are then reviewed. Adaptations for distinct particle species, pitfalls, and 'forgotten' or underrepresented technologies are considered as well. The article is topped off with our own development of a method for virion preparation, rooted in historical protocols. It combines selective re-solubilization of polyethylene glycol (PEG) virion raw precipitates with density step gradient centrifugation in biocompatible iodixanol formulations, yielding ready-to-use particle suspensions. This newly established protocol and some considerations for perhaps worthwhile further developments could serve as putative stepping stones towards preparation procedures appropriate for routine practical uses of these multivalent soft-matter nanorods.

Analyzing and modeling of CO purging for high-temperature proton exchange membrane fuel cells

Purging offers a straightforward and cost-effective means of eliminating inert gases that accumulate in high-temperature proton exchange membrane fuel cells (HT-PEMFC) operating in dead-end anode (DEA) mode. Nevertheless, earlier studies primarily concentrated on inert gases, overlooking the significant challenge posed by the strong adsorption of CO within HT-PEMFC, complicating the use of inert gas methods for CO purification. This paper presents an analytical model that was validated experimentally. Leveraging this model, the paper analyzes the crucial parameter of CO concentration within the anode and deduces theoretical extreme values. Subsequently, it proposes purging strategies tailored to different operational conditions. The findings indicate that the minimum CO concentration within HT-PEMFC is influenced by current, feed gas flow rate, and feed gas CO concentration. Additionally, the maximum CO concentration is affected by the off-duration of the purge valve in addition to these factors. Specifically, under the operating condition of 473.15 K, adopting a CO concentration threshold purge strategy is recommended, whereas under the operating condition of 448.15 K, voltage drop and CO concentration threshold purge strategies should be respectively implemented above and below the cutoff line based on the current. This research contributes to mitigating the issue of CO accumulation in DEA mode.

A spectrometric analysis of variedly purified cinnabar in a siddha drug- linga chendhooram.

A siddha drug, linga chendhooram was prepared from cinnabar (lingam) and Citrullus colocynthis L. The transition of heavy metals concentration throughout theprocess were analysed to comprehend the significance ofdrug preparatory methods. In addition to that the main constituent cinnabar was purified from two different methods to comparatively analyse the significance of purification methods. Atomic absorption spectrometric studies were employed to obtain the concentration of class I heavy metals (lead, arsenic, cadmium and mercury) in all five samples- raw cinnabar (R), cinnabar purified (P1 and P2) from purification method 1 and 2, linga chendhooram (D1 and D2) prepared from P1 and P2. Based on the permissible limits given by The Ayurvedic Pharmacopoeia of India, except cadmium the concentrations of all other three heavy metals were found to be above the limit in P1, P2, D1 and D2. According to the oral Permitted Daily Exposure values for elemental impurities given in ICH Q3D(R1) Guidelines, D1 was within the permissible limits for both single and double oral doses whereas D2 showed a slight increase in the concentration of lead in a single oral dose itself. The drug preparatory method showed a reduction of the heavy metals concentration and comparative analysis of the purification methods revealed a substantial reduction of heavy metals concentration in the end drug D1 when compared with D2 showing that the methods of purification and drug preparation in siddha system plays a vital role in reducing the concentrations of heavy metals accordingly.

Identification of Phorbol Ester and its Degradation by Traditional Purification Method in the Root of Baliospermum montanum (Willd.) Muell. Arg

Identification of Phorbol Ester and its Degradation by Traditional Purification Method in the Root of Baliospermum montanum (Willd.) Muell. Arg

Sterilization potential of Gas-Water Mixed Ion (GWMI) technology and its device for microorganisms in the built environment

As human societies progress, novel infectious diseases and extensive health challenges continuously emerge. There is a growing demand for low-cost, safe, and broad-spectrum microbial sterilization technologies within architectural environments. This study introduces a Gas-Water Mixed Ion (GWMI) technology combining negative ions and electrostatic atomization. Due to the strong oxidizing properties of the hydroxyl radicals (·OHs) produced, it demonstrates excellent bactericidal effects and has been widely applied in water treatment. However, its potential for air sterilization has not been fully explored. Using Escherichia coli (E. coli) as a target strain, this study investigates the sterilization potential of this technology in various spatial settings and evaluates its energy consumption from an economic perspective. The results indicate that the device, designed based on the GWMI technology, achieves more than 70 % bactericidal efficiency at the maximum distance in spaces of 100 L and 200 L. In a 30 m³ experimental chamber, the natural diffusion of the microbial ions extends approximately 36 cm, with localized air supply enhancing the spread of these ions up to 90 cm, where the sterilization rate still reaches 33.33 % and over 50 % within the 70 cm range. Compared to other microbial purification methods, this technology consumes less energy. The GWMI technology efficiently eliminates environmental microbes, provides valuable data for future implementation in building environments, and offers a novel approach to fostering low-carbon, healthy architectural settings.

Extraction, Purification, and in vitro Antioxidant Activity Assessment of Total Flavonoids from the Aerial Parts of Tetrastigma hemsleyanum

Background The effective extractives of Tetrastigma hemsleyanum ( T. hemsleyanum) are useful, but this plant was not fully utilized in rural China. In this study, flavonoids from the aerial parts of T. hemsleyanum were extracted, and the purification method and the antioxidant capability were explored. Purpose This study is to explore the optimized purification method and the biological capability of the total flavonoids extracted from T. hemsleyanum. Materials and Methods The optimal extraction conditions were determined by single-factor and Box-Behnken design experiments. The antioxidant activities were assessed by analyzing their capability to scavenge 2,2-diphenyl-1-picrylhydrazyl and OH free radicals. Results and Discussion The optimal conditions for the extraction of the total flavonoids were as follows: ethanol volume fraction 60%, liquid-to-material ratios 35:1 mL/g, temperature 45℃, and time 85 min. The extraction rate of the total flavonoids was (3.59 ± 0.03)%. NKA-9 is an ideal macroporous resin for purification. The optimized purification process conditions of flavonoids were mass concentration of adsorption solution 1.50 mg/mL, pH value of adsorption solution 4.0, sample loading flow rate 2 BV/h, ethanol volume fraction in desorption process 60%, desorption flow rate 2 BV/h and elution volume 4 BV. After crude extracts were purified by NKA-9 macroporous resin, the content of the total flavonoids enhanced from (21.76 ± 0.18)% to (58.92 ± 0.22)%. The results of the experiments for antioxidant activity showed that the half maximal inhibitory concentration (IC50) values of the purified flavonoids extracted were 33.1and 42.7 µg/mL, respectively. Conclusion The results of this study indicated that the flavonoids in T. hemsleyanum have good antioxidant activity in vitro and deserve exploring in further pharmacological studies.

Precise measurement of Fe isotopes in marine and biological samples by pseudo-high-resolution multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS).

This paper introduces an enhanced technique for analyzing iron isotopes in complex marine and biological samples. A dedicated iron purification method for biological marine matrices, utilizing three ion exchange columns, is validated. The MC-ICPMS in pseudo-high-resolution mode determines precise iron isotopic ratios, with sensitivity improved through the DSN-100 desolvating nebulizer system and Apex-IR. Only 2µg of iron on DSN versus 1µg on Apex is needed for six replicates (30-60 times improvement) while 10 to 20µg is required for a single measurement on awet system considering the resolution power (Rp) is maintained at 11,000-13,000. The Ni-doping method with a Fe/Ni ratio of 1 yields more accurate isotopic ratios than standard-sample bracketing alone. Measurement reproducibility of triplicate samples from marine biological experiments on MC-ICPMS is ± 0.03‰ (2SD) for δ56Fe and ± 0.07‰ for δ57Fe (2SD). This study introduces a novel iron purification process specifically designed for marine and biological samples, enhancing sensitivity and enabling more reliable measurements with smaller sample sizes and reduced uncertainties. It proposes iron isotopic compositions for biological reference materials, offering a valuable reference dataset in diverse scientific disciplines.

Solar Water Purifier Machine

The Solar Water Purifier Machine (SWPM) is an innovative device designed to provide clean, potable water using solar energy, particularly in remote or disaster affected areas. This paper explores the design, functionality, and effectiveness of the SWPM, highlighting its potential impact on communities lacking access to safe drinking water. The study includes a detailed analysis of the components, the working mechanism, and a comparison with traditional water purification methods. Additionally, it examines the environmental benefits and economic feasibility of deploying SWPMs in various regions . The purified water is then stored in a tank for later use. The machine is designed to be low cost, portable, and easy to operate, making it ideal for use in areas where access to clean water is limited. The solar powered operation ensures sustainability and reduce the carbon footprint, making it an environmentally friendly solution for water purification.

Determination of calcium β-hydroxy-β-methyl butyrate content in milk and dairy products by solid-phase extraction and high performance liquid chromatography

In this paper, an analytical method based on solid-phase extraction (SPE) purification and high-performance liquid chromatography method (HPLC) was developed for the first time to determine the content of calcium β-hydroxy-β-methyl butyrate (CaHMB) in milk and dairy products. The quantitative detection was performed by HPLC with diode array detector (DAD) under external standard method. The limit of quantification (LOQ), calculated as 10 times the standard deviation, was 0.10 g/100 g. The average recoveries were in the range of 92.40–103.00 %, with relative standard deviations (RSDs) of 1.25–3.77 %, measured at three concentration levels. The real sample analysis results showed that CaHMB was detected in infant formula, formulated milk powder, and milkshake samples, the contents of which were in the range of 0.60–8.66 g/100 g, respectively. The developed method features good purification effect, good separation specificity, good repeatability, accuracy and reliability, and can meet the content determination of CaHMB in milk and dairy products.

A Janus membrane with electro-induced multi-affinity interfaces for high-efficiency water purification.

Drinking water with micropollutants is a notable environmental concern worldwide. Membrane separation is one of the few methods capable of removing micropollutants from water. However, existing membranes face challenges in the simultaneous and efficient treatment of small-molecular and ionic contaminants because of their limited permselectivity. Here, we propose a high-efficiency water purification method using a low-pressure Janus membrane with electro-induced multi-affinity. By virtue of hydrophobic and electrostatic interactions between the functional interfaces and contaminants, the Janus membrane achieves simultaneous separation of diverse types of organics and heavy metals from water via single-pass filtration, with an approximately 100% removal efficiency, high water flux (>680 liters m-2 hour-1), and 98% lower energy consumption compared with commercial nanofiltration membranes. The electro-induced switching of interfacial affinity enables 100% regeneration of membrane performance; thus, our work paves a sustainable avenue for drinking water purification by regulating the interfacial affinity of membranes.

A review of the extraction and purification methods, biological activities, and applications of active compounds in Acanthopanax senticosus

Acanthopanax senticosus (AS) is a geo-authentic crude medicinal plant that grows in China, Korea, Russia, and Japan. AS contains bioactive compounds such as eleutherosides, polysaccharides, and flavonoids. It is also a key traditional herb in the Red List of Chinese Species. AS is mainly distributed in Northeast China, specifically in Heilongjiang, Jilin, and Liaoning provinces. Its active compounds contribute to significant biological activities, including neuroprotective, antioxidant, anti-fatigue, and antitumor effects. However, the extraction methods of active compounds are complex, the extraction efficiency is poor, and the structure–activity relationship is unclear. This study focused on the nutrients in AS, including protein, carbohydrates, and lipids. Particularly, the active ingredients (eleutherosides, polysaccharides, and flavonoids) in AS and their extraction and purification methods were analyzed and summarized. The biological activities of extracts have been reviewed, and the mechanisms of anti-oxidation, antitumor, anti-inflammation, and other activities are introduced in detail. The applications of AS in various domains, such as health foods, medicines, and animal dietary supplements, are then reported. Compared with other extraction methods, ultrasonic or microwave extraction improves efficiency, yet they can damage structures. Challenges arise in the recovery of solvents and in achieving extraction efficiency when using green solvents, such as deep eutectic solvents. Improvements can be made by combining extraction methods and controlling conditions (power, temperature, and time). Bioactive molecules and related activities are exposited clearly. The applications of AS have not been widely popularized, and the corresponding functions require further development.

Efficient and easily recyclable photocatalytic reduction of Se(IV) from wastewater using stable TiO2/BiOBr/cloth: Mechanism insight and machine learning modeling

Photocatalytic technology is extensively employed for the reductive removal of water contaminants; however, it contends with low catalytic efficiency and challenges in catalyst recovery. In this study, we propose integrating experimental procedures with artificial intelligence modeling to enhance the purification of Se(IV)-contaminated wastewater. We present an efficient, easily recyclable, and cost-effective strategy for photocatalyst fabrication. Specifically, we develop a novel method for Se(IV) removal by immobilizing TiO2/BiOBr onto glass fiber cloth surfaces using chitosan for Se(IV) reduction in aqueous solutions. The TiO2/BiOBr/cloth (TB-4/cloth) catalyst achieves a remarkable 99.2 % Se(IV) removal within 2 h under visible light and maintains excellent Se(IV) reduction photocatalytic activity (86.4 %) even after eight cycles, remaining easily reusable. Additionally, we develop two machine learning models, namely artificial neural network (ANN) and long short-term memory (LSTM), to validate the anticipated experimental outcomes. Both models exhibit high accuracy and predictive capability (R2 > 0.99, RMSE < 0.03). This study introduces a novel approach that combines experimentation with artificial intelligence modeling, paving the way for future advancements in Se(IV)-contaminated wastewater purification methods.

Rapid determination of 111 anti-infective drugs possibly added in cosmetics using high-performance liquid chromatography-tandem mass spectrometry with scheduled multiple reaction monitoring.

Illegal addition of anti-infective drugs to cosmetics at low concentrations has been found. The illicit addition of anti-infective drugs encompasses a wide variety of medications. The current sample purification methods are inadequate to detect all these compounds. A sensitive, wide-coverage, and weak-matrix-effect measurement method needs to be established to address this issue. Samples were extracted using acetonitrile, diluted 25 times, and then analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to detect 111 anti-infective drugs. The method was validated and assessed for matrix effect before being applied to cosmetic products. The calibration curves for the analytes exhibited a strong correlation coefficient (r > 0.995). The limit of detection ranged from 0.006 to 0.6mg/kg. Matrix effects were significantly improved after a 25-fold dilution. The method was successfully applied to various cosmetics. Two of 82 samples tested contained lincomycin and miconazole, respectively. The developed method is quick and reliable to analyze anti-infective drugs in cosmetics, with potential for both qualitative and quantitative analyses. It is a valuable tool for cosmetic research and development, contributing to safer and more effective cosmetic products.

Efficient Metal Extraction from Dilute Solutions: A Review of Novel Selective Separation Methods and Their Applications

Notable increases in metal consumption and declining ore grades in recent decades have stressed the significance of dilute solutions as secondary sources of valuable metals. Moreover, environmental considerations and the imperative of sustainable development have further emphasized their treatment. Therefore, finding an efficient solution for separating metals from dilute solutions has attracted the attention of numerous researchers. This paper reviews the purification processes of dilute solutions and highlights key achievements of published research works. Although this study focuses on evaluating the efficiency of recently developed aqueous-phase purification methods, such as immobilized ligands, ionic liquids, and air-assisted solvent extraction, the application of conventional processes to treat these solutions, such as solvent extraction, ion exchange, membranes, chemical precipitation, and adsorption are also briefly outlined. To provide a comprehensive assessment, more than 200 research articles were reviewed, and their key findings are stated in this study. This research contributes to the advancement of knowledge of metal recovery from dilute solutions and sheds light on the dynamic evolution of this field.

Extraction, Physicochemical Properties, and In Vitro Antioxidant Activities of Chondroitin Sulfate from Bovine Nose Cartilage.

Beef is an important high-nutrition livestock product, and several byproducts, such as bovine cartilage, are produced during slaughter. To effectively utilize these agricultural and pastoral byproducts, combined (trypsin-papain) enzymolysis and cetylpyridine chloride purification methods were used to obtain chondroitin sulfate (CS) from the nasal cartilage of Shaanxi Yellow cattle. The effects of pH, temperature, and time on the CS yield during enzymatic hydrolysis were investigated, and the CS extraction process was optimized using response surface methodology. The best yield of CS was 21.62% under the optimum conditions of pH 6.51, temperature of 64.53°C, and enzymolysis time of 19.86 h. The molecular weight of CS from Shaanxi cattle nasal cartilage was 89.21 kDa, glucuronic acid content was 31.76 ± 0.72%, protein content was 1.12 ± 0.03%, and sulfate group content was 23.34 ± 0.08%. The nasal cartilage CS of the Yellow cattle showed strong DPPH•, •OH, and ABTS+• radical scavenging abilities and ferrous reduction ability in the experimental concentration range. This study could contribute to "turn waste into treasure" and improve the comprehensive utilization of regional characteristic biological resources.

The Multifaceted Effects of Non-Steroidal and Non-Opioid Anti-Inflammatory and Analgesic Drugs on Platelets: Current Knowledge, Limitations, and Future Perspectives.

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most widely utilized pharmaceuticals worldwide. Besides their recognized anti-inflammatory effects, these drugs exhibit various other pleiotropic effects in several cells, including platelets. Within this article, the multifaceted properties of NSAIDs on platelet functions, activation and viability, as well as their interaction(s) with established antiplatelet medications, by hindering several platelet agonists' pathways and receptors, are thoroughly reviewed. The efficacy and safety of NSAIDs as adjunctive therapies for conditions involving inflammation and platelet activation are also discussed. Emphasis is given to the antiplatelet potential of commonly administered NSAIDs medications, such as ibuprofen, diclofenac, naproxen and ketoprofen, alongside non-opioid analgesic and antipyretic medications like paracetamol. This article delves into their mechanisms of action against different pathways of platelet activation, aggregation and overall platelet functions, highlighting additional health-promoting properties of these anti-inflammatory and analgesic agents, without neglecting the induced by these drugs' side-effects on platelets' functionality and thrombocytopenia. Environmental issues emerging from the ever-increased subscription of these drugs are also discussed, along with the need for novel water treatment methodologies for their appropriate elimination from water and wastewater samples. Despite being efficiently eliminated during wastewater treatment processes on occasion, NSAIDs remain prevalent and are found at significant concentrations in water bodies that receive effluents from wastewater treatment plants (WWTPs), since there is no one-size-fits-all solution for removing all contaminants from wastewater, depending on the specific characteristics of the wastewater. Several novel methods have been studied, with adsorption being proposed as a cost-effective and environmentally friendly method for wastewater purification from such drugs. This article also presents limitations and future prospects regarding the observed antiplatelet effects of NSAIDs, as well as the potential of novel derivatives of these compounds, with benefits in other important platelet functions.

Comparison of Synthetic Pathways for Obtaining Fluorescent Nanomaterials Based on Halloysite and Carbon Dots for Potential Biological Sensing.

Recently, fluorescent sensors have gained considerable attention due to their high sensitivity, low cost and noninvasiveness. Among the different materials that can be used for this purpose, carbon dots (CDs) represent valuable candidates for applications in sensing. These, indeed, are easily synthesized, show high quantum yield and are highly biocompatible. However, it was pointed out that the photoluminescence properties of these nanomaterials are strictly dependent on the synthetic and purification methods adopted. The presence of halloysite nanotubes (HNTs), a natural, low cost and biocompatible clay mineral, has been found to be efficient in obtaining small and highly monodispersed CDs without long and tedious purification techniques. Herein, we report the comparison of synthetic pathways for obtaining halloysite-N-doped CDs (HNTs-NCDs) that could be used in biological sensing. One was based on the synthesis of N-doped CDs by a bottom-up approach on HNTs' surface by a MW pyrolysis process; the other one was based on the post-modification of pristine N-doped CDs with halloysite derivatives. The evaluation of the best synthetic route was performed by different physico-chemical techniques. It was found that the bottom-up approach led to the formation of N-doped CDs with different functional groups onto the HNTs' surface. This evidence was also translated in the different fluorescence quantum yields and the existence of several functional groups in the obtained materials was investigated by potentiometric titrations. Furthermore, the ability of the synthesized nanomaterials as sensors for Fe3+ ions detection was assessed by spectroscopic measurements, and the cellular uptake was verified by confocal/fluorescence microscopies as well.

Pulsed radio wave as a sustainable control technology to improve indoor air quality

The need for technologies that can clean the air indoors has grown in pace with the rise in outside pollution. Maintaining interior environment adaptability requires a permanent air purification system that may be utilized to control PM2.5/10. In addition to more traditional methods of air purification, developing advanced control systems that effectively reduce PM levels sustainably is necessary. Pulsed radio waves may expedite the dry deposition of particles having aerodynamic dimensions of less than 30 µm. The charging and coagulation processes are evaluated in an indoor restricted environment. Experimental results reveal a similar pattern to the Monte Carlo models. Distribution of charge due to the nature of the charging environment increases the coagulation rate. Contained experimental testing confirms the filtering system functions as expected, corroborated by the present research. Daily average levels of PM2.5 and PM10 were lowered by between 55 and 41% according to a study done in three indoor settings using the control technology. Research conducted throughout all seasons showed that the approach was consistently efficient in reducing PM2.5/10. It was shown that PM concentrations could be lowered by around 45 percent using pulse radio wave technology, leading to this conclusion. The use of electromagnetic waves (EM waves) to eliminate air pollution has been suggested as a radical new approach. Considering the limitations of already used strategies, this is of paramount significance while considering solutions to control air pollution.

Enrichment of Total Flavonoids and Licochalcone A from Glycyrrhiza inflata Bat. Residue Based on a Combined Membrane-Macroporous Resin Process and a Quality-Control Study.

Glycyrrhiza inflata Bat. produces a lot of licorice waste after water extraction, which also retains abundant total flavonoids (TFs) and licochalcone A. However, licorice residue is often wasted due to the lack of good utilization of resources in practical applications. This study first screened the optimal membrane pore size and resin type and then explored the mechanism and conditions of the adsorption of TFs on the resin. Then, different combinations and sequences of membrane and macroporous resin (MR) methods were investigated. It was found that using the membrane method for initial purification, followed by the MR method for further purification, yielded the best purification results. Next, response surface methodology was utilized to investigate the resin's dynamic desorption conditions for TFs. Finally, the TF purity increased from 32.9% to 78.2% (2.38-fold) after purification by a combined membrane-MR process; the purity of licochalcone A increased from 11.63 mg·g-1 to 22.70 mg·g-1 (1.95-fold). This study verified the feasibility of enriching TFs and licochalcone A from licorice residue using a membrane-MR coupling method. In addition, a quality-control method was established using a fingerprinting method on the basis of ultrahigh-performance liquid chromatography (UPLC) to ensure the stability of the enrichment process.

Inorganic flocculant-based soybean urease extraction and its effect on biomineralization

Enzyme induced carbonate precipitation (EICP) based on self-extracted crude soybean urease solution (CSUS) is a promising method for soil improvement. However, the deionized water-extracted CSUS usually contains a large amount of impurities that easily lead to bioclogging during the biogrouting process, resulting in a nonuniform biomineralization effect. In this study, a purification method using inorganic flocculants is proposed to extract CSUS with relatively high purity and urease activity (UA) for EICP method. Seven commonly used inorganic flocculants were adopted in this study, including KAl(SO4)2•12H2O, AlCl3•6H2O, Al2(SO4)3•18H2O, Fe2(SO4)3, poly aluminum chloride, poly ferric sulfate, and poly aluminum ferric chloride. Three sets of tests, including CSUS extraction tests, solution tests, and sand column treatment tests, were conducted to investigate the feasibility and validity of this purification method. The test results show that inorganic flocculants could effectively reduce the turbidity of the extracted CSUS, avoid the bioclogging during biogrouting, and thus improve the biomineralization effect of the CSUS-based EICP method. Compared with deionized water-based CSUS, at least 60% of the impurities in CSUS can be removed at optimal flocculant contents when the soybean powder content is 100 g/L. On the other hand, the flocculants would also cause a reduction in the UA of the extracted CSUS. Considering the UA, turbidity, and biomineralization effect of the extracted CSUS, the optimal inorganic flocculants and their contents are recommended to be 3.0 g/L for KAl(SO4)2•12H2O, 2.0 g/L for AlCl3•6H2O, 2.5 g/L for Al2(SO4)3•18H2O under the tested conditions, respectively.