Monitoring dynamics of biocrust rehabilitation in acid-saturated desert soils.

The study explores the aftermath of a wastewater reservoir failure in a phosphate fertilizer industry, resulting in the release of acidic water containing phosphorus and sulfate compounds into the Ashalim stream's Nature Reserve in the Judean desert, which affected the soil surface biological crusts (biocrusts) layer. The study aims to examine contamination effects on biocrusts over 3 years at two research sites along the stream, compare effects between contaminated sites, assess rehabilitation treatments, and examine their impact on soil characteristics. Hypotheses suggest significant damage to biocrusts due to acidic water flow, requiring human intervention for accelerated restoration. The results indicate adverse effects on biocrust properties, risking its key role in the desert ecosystem. The biocrust layer covering the stream's ground surface suffered significant physical, chemical, and biological damage due to exposure to industrial process effluents. However, soil enrichment treatments, including biocrust components and organic material, show promising effects on biocrust recovery.

Precooling via immersion in CO2-enriched water at 25°C decreased core body temperature but did not improve 10-km cycling time trial in the heat.

This study compared the effects of precooling via whole-body immersion in 25°C CO2-enriched water (CO2WI), 25°C unenriched water (WI) or no cooling (CON) on 10-km cycling time trial (TT) performance. After 30 min of precooling (CO2WI, CON, WI) in a randomized, crossover manner, 11 male cyclists/triathletes completed 30-min submaximal cycling (65%VO2peak), followed by 10-km TT in the heat (35°C, 65% relative humidity). Average power output and performance time during TT were similar between conditions (p = 0.387 to 0.833). Decreases in core temperature (Tcore) were greater in CO2WI (-0.54 ± 0.25°C) than in CON (-0.32 ± 0.09°C) and WI (-0.29 ± 0.20°C, p = 0.011 to 0.022). Lower Tcore in CO2WI versus CON was observed at 15th min of exercise (p = 0.050). Skin temperature was lower in CO2WI and WI than in CON during the exercise (p < 0.001 to 0.031). Only CO2WI (1029 ± 305 mL) decreased whole-body sweat loss compared with CON (1304 ± 246 mL, p = 0.029). Muscle oxygenation by near-infrared spectroscopy (NIRS), thermal sensation, and thermal comfort were lower in CO2WI and WI versus CON only during precooling (p < 0.001 to 0.041). NIRS-derived blood volume was significantly lower in CO2WI and WI versus CON during exercise (p < 0.001 to 0.022). Heart rate (p = 0.998) and rating of perceived exertion (p = 0.924) did not differ between conditions throughout the experiment. These results suggested that CO2WI maybe more effective than WI for enhanced core body cooling and minimized sweat losses.

[Effects of humic acid water-soluble fertilizer on growth and physiological characteristics of Bupleurum chinense seedlings].

The effects of humic acid water-soluble fertilizer on the growth and physiological characteristics of Bupleurum chinense seedlings(Zhongchai No.1) were studied by using a single factor experiment design. When the seedling age was 60 days, the humic acid water-soluble fertilizer was diluted 1 200 times(T1), 1 500 times(T2), 1 800 times(T3), and 2 100 times(T4) for seedling treatment, respectively, and water was used as the control(CK). The effects of different treatments on growth indexes, biomass accumulation, root activity, antioxidant enzyme activity, membrane lipid peroxidation, and photosynthetic characteristics of B. chinense seedlings were analyzed after 30 days. The results showed that compared with CK, stem height, leaf number, root diameter, and root length of the B. chinense seedlings under T3 treatment were significantly increased by 36.82%, 37.03%, 42.78%, and 22.38%, respectively. Root fresh weight, leaf fresh weight, root dry weight, and leaf dry weight under T3 treatment were significantly increased by 90.36%, 98.68%, 123.84%, and 104.38%, respectively. In addition, humic acid water-soluble fertilizer also enhanced TTC reducing activity of the root of B. chinense seedlings, inhibited malonaldehyde(MDA) content, increased superoxide dismutase(SOD), peroxidase(POD), and catalase(CAT) enzyme activities, improved chlorophyll content, and enhanced P_n, G_s, T_r, and other photosynthetic parameters. In conclusion, the application of humic acid water-soluble fertilizer diluted 1 800 times can significantly promote the growth of B. chinense seedlings, enhance root vitality, improve seedling stress resistance, and enhance photosynthesis. The results of this study can provide a theoretical basis for fertilization of B. chinense seedlings.

The influence of the acid water of the Banyupait River on the community health in Bantal village, Asembagus, Indonesia.

The pH of Mount Ijen crater water is 0-2, resulting in water that is acidic and sulfurous. A fault near the Mount Ijen Crater causes seepage so that acidic water flows into the Banyupait River. Chemical elements and heavy metals originating from the river pollute groundwater and plants. As a result, people around the river consume heavy metals. This research aims to determine the quality of river water and groundwater, as well as determine community factors that are susceptible to dental fluorosis. The methodology used is field mapping and laboratory analysis. For water samples, the Atomic Absorption Spectrophotometer (AAS) method is used. The pH of river water at the research location exceeds the quality standard, namely pH 4-5.5. Meanwhile, groundwater fluorine and sulfate elements exceed quality standards, namely fluorine of 0.6171 mg/L and 0.6870 mg/L, and sulfate ranging from 325-683 mg/L. These two elements cause symptoms of dental fluorosis. Meanwhile, the community factors most susceptible to dental fluorosis are people in the adult age category, and the last level of education is elementary school. This is because the Banyupait River water and groundwater are exposed to fluorine and sulfate water originating from seepage from the Mount Ijen Crater.

Virucidal efficacy of hypochlorous acid water for aqueous phase and atomization against SARS-CoV-2.

Coronavirus disease 2019 (COVID-19) is an infectious viral disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that emerged at the end of 2019. SARS-CoV-2 can be transmitted through droplets, aerosols, and fomites. Disinfectants such as alcohol, quaternary ammonium salts, and chlorine-releasing agents, including hypochlorous acid, are used to prevent the spread of SARS-CoV-2 infection. In the present study, we investigated the efficacy of ionless hypochlorous acid water (HOCl) in suspension and by spraying to inactivate SARS-CoV-2. The virucidal efficacy of HOCl solution in tests against SARS-CoV-2 was evaluated as 50% tissue culture infectious dose. Although the presence of organic compounds influenced the virucidal efficacy, HOCl treatment for 20 s was significantly effective to inactivate Wuhan and Delta strains in the suspension test. HOCl atomization for several hours significantly reduced the SARS-CoV-2 attached to plastic plates. These results indicate that HOCl solution with elimination containing NaCl and other ions may have high virucidal efficacy against SARS-CoV-2. This study provides important information about the virucidal efficacy and use of HOCl solution.

Profiling the Gut Microbiome Unraveled Signature Bacterial Groups in Autoimmune Diabetes, which Remain Unperturbed by the Low Ionic Strength of the Drinking Water in NOD mice.

BACKGROUND: Non-obese diabetic (NOD) mice develop type 1 diabetes (T1D) spontaneously and serve as a good model for investigating the underlying pathological mechanisms and devising novel treatment procedures. Although acid water consumption has been reported to exaggerate or reduce diabetes incidence in female NOD mice by two groups, the causative bacteria responsible for these contrasting changes remain unclear. On the contrary, we and others failed to observe the effect of acid water consumption on diabetes incidence. This study aimed to determine whether the consumption of low-pH drinking water could alter the frequencies of prominent bacterial groups independent of diabetes manifestation. METHODS: Six-week-old female NOD mice maintained on acidified drinking water at the Jackson Laboratories were transferred to neutral pH water or continuously provided with low pH drinking water at our facility. Diabetes was monitored weekly using a glucometer. Using the 454-pyrosequencing methodology, we profiled the gut microbiome of mice transferred to neutral water and developed diabetes. Further, we performed quantitative real-time polymerase chain reactions (qRT-PCR) using primers specific for prominent 16S rRNA genes on the fecal DNA of mice provided with low pH or neutral water and displayed diabetes similarly. RESULTS: Consistent with our earlier report, the incidence of T1D was robust (80-100%) regardless of whether female NOD mice consumed acid (~pH 2.9) or neutral water. The 454-pyrosequencing of fecal DNA indicated no substantial influence of transferring mice to neutral pH drinking water on the gut microbiome. To validate these findings, we conducted qRT-PCR on the fecal DNA of mice longitudinally from six weeks of age to adulthood that consumed acidic or neutral pH water and developed diabetes similarly. Among the 15 selected bacterial groups examined, the frequency of Lactobacillus sp. remained consistently lower (p < 0.05) throughout the life of NOD mice compared to that found in young (6-week-old) mice, regardless of the pH of the drinking water. The relative frequencies of the Firmicutes Ruminococcaceae and the Bactereoidetes members Anaerophaga sp. and Paludibacter sp. increased significantly (p < 0.05) during the transition to the overtly diabetic stage irrespective of the ionic strength of the drinking water. Interestingly, the Firmicutes members Clostridium coccoides, C. leptum, and Lachnospiraceae and the Bacteroidetes members Bacteroides sp. and Prevottella sp. remained unchanged throughout the analysis irrespective of the pH of the drinking water. Paradoxically, the representations of Akkermansia muciniphila and the segmented filamentous bacteria implicated in diabetes protection did not differ regardless of the age or the ionic strength of the drinking water. CONCLUSIONS: The data presented herein validate the lack of influence of acidic drinking water on T1D development in female NOD mice. Diabetes was associated with the lower representation of Lactobacillus sp. throughout life, which was not influenced by the differing pH of the drinking water. Significantly, segmented filamentous bacteria and A. muciniphila, previously implicated in protection against T1D, were not perturbed by the varying pH of the water consumed. These data indicate that although acidified water consumption was reported previously to diminish specific gastrointestinal pathogens, it failed to perturb gut commensals that influence diabetes development.

Microbiological analysis concerning the antibacterial effect of atomized Ionless® hypochlorous acid water in a nursery school environment.

INTRODUCTION: In daycare centers, infants come in close contact with each other, and contact, droplet, and mouth-to-mouth infections may occur owing to sharing of toys. Additional effective disinfection methods should be considered aside from wiping with disinfectants-including alcohol or sodium hypochlorite solution-for environmental disinfection of daycare centers. We aimed to examine the usefulness of hypochlorous acid water atomization in the effective disinfection of the classroom environment and toys at a nursery school. METHODS: Environmental cultures of the nursery and toys were prepared to evaluate the species and bacterial load and to assess the contaminated areas. Staphylococcus aureus petri dishes were placed at high-frequency contact sites, and hypochlorous acid water was atomized to achieve a 0.03-ppm atmospheric chlorine concentration. After the atomization, the amount of S. aureus bacteria on the Petri dish and the changes in bacterial count isolated from the environment and toys were evaluated. RESULTS: Hypochlorous acid water atomization was performed for 5 h to avoid condensation. After a 3-h atomization, ≥99.99% of S. aureus was eliminated on petri dishes; furthermore, a significant disinfection effect was observed on environmental bacteria at least 1 h after atomization. For rubber and textile toys, the significant disinfection effect was observed 1 h after atomization, and for plastic toys, the effect was observed 3 h after atomization. CONCLUSIONS: Hypochlorous acid water atomization is a useful strategy to disinfect nursery school classrooms.

A Monte Carlo approach to study the effect of ions on the nucleation of sulfuric acid-water clusters.

The nucleation of sulfuric acid-water clusters is a significant contribution to the formation of aerosols as precursors of cloud condensation nuclei (CCN). Depending on the temperature, there is an interplay between the clustering of particles and their evaporation controlling the efficiency of cluster growth. For typical temperatures in the atmosphere, the evaporation of H2 SO4 H2 O clusters is more efficient than the clustering of the first, small clusters, and thus their growth is dampened at its early stages. Since the evaporation rates of small clusters containing an HSO 4 - ion are much smaller than for purely neutral sulfuric acid clusters, they can serve as a central body for the further attachment of H2 SO4 H2 O molecules. We here present an innovative Monte Carlo model to study the growth of aqueous sulfuric acid clusters around central ions. Unlike classical thermodynamic nucleation theory or kinetic models, this model allows to trace individual particles and thus to determine properties for each individual particle. As a benchmarking case, we have performed simulations at T = 300 K a relative humidity of 50% with dipole and ion concentrations of c dipole = 5 × 10 8 - 10 9 cm - 3 and c ion = 0 - 10 7 cm - 3 . We discuss the runtime of our simulations and present the velocity distribution of ionic clusters, the size distribution of the clusters as well as the formation rate of clusters with radii R ≥ 0.85 nm . Simulations give reasonable velocity and size distributions and there is a good agreement of the formation rates with previous results, including the relevance of ions for the initial growth of sulfuric acid-water clusters. Conclusively, we present a computational method which allows studying detailed particle properties during the growth of aerosols as a precursor of CCN.

Acid Water-ground Nano-realgar Is Superior to Crude Realgar in Promoting Apoptosis of MCF-7 Breast Cancer Cells.

OBJECTIVE: Realgar is a traditional mineral Chinese medicine with antitumor effects, but it has high toxicity and low efficacy in its crude form. The purpose of this study was to optimize realgar to increase its efficacy and therapeutic potential. METHODS: Crude realgar (CR) was mechanically ground to obtain nano-realgar (NR), and then nano-realgar processed products (NRPPs) were obtained using three different traditional Chinese medicine processing methods: grinding in water, acid water, and alkali water, respectively. RESULTS: By analyzing the size distribution of nanoparticles and the content of arsenic trioxide (As2O3; ATO), we found that acid water-ground NRPPs had the characteristics of high purity and low toxicity. The effects of CR, NR, and NRPPs on proliferation, cell cycle, and apoptosis of MCF-7 cells were detected, and the ability of NRPPs to induce apoptosis in MCF-7 cells was analyzed. The results showed that the average particle size of acid water-ground NRPPs was 137.7 nm, and the content of ATO was 2.83 mg/g. Acid water-ground NRPPs showed better effects on inhibiting proliferation, cell cycle, and apoptosis of MCF-7 cells than CR and NR. Western blot assays further confirmed that acid water-ground NRPPs upregulated the protein expression of TP53, Bax, cytochrome c, caspase-9, and caspase-3 in MCF-7 cells (P<0.05) and inhibited the expression of Bcl-2 (P<0.05). CONCLUSION: These results suggest that acid water-ground NRPPs can induce apoptosis of MCF-7 cells through regulating mitochondrial-mediated apoptosis, providing evidence for the clinical application of realgar.

Rapid in vitro virucidal activity of slightly acidic hypochlorous acid water toward aerosolized coronavirus in simulated human-dispersed droplets.

The virucidal activities were evaluated by spraying slightly acidic hypochlorous acid waters (SAHWs) containing various concentrations of free available chlorine - 100, 200, 300 and 500 ppm (SAHW-100, -200, -300 and -500, respectively) - toward aerosol of an avian coronavirus (infectious bronchitis virus: IBV). The viral solution was supplemented with 0.5% fetal bovine serum (FBS) to simulate normal human droplets generated by sneezing or coughing in a real-life scenario. The virus containing 0.5% FBS was sprayed and exposed to SAHWs for a few seconds in a closed chamber, before reaching the air sampler. The results showed that IBV exposed to SAHW-100 and -200 for a few seconds decreased by 0.21 log10 and 0.80 log10, respectively, compared to the pre-exposed samples to SAHWs as controls. On the other hand, reductions of 1.16 log10 and 1.67 log10 were achieved following the exposure to SAHW-300 and -500, respectively, within a few seconds. These results suggest that SAHWs have rapid in vitro virucidal activity toward aerosolized IBV. The findings obtained for IBV might basically be applicable in relation to SARS-CoV-2, given the resemblance between the two viruses. To prevent human-to-human transmissions by aerosols, the inactivation of viruses in the air by exposure to SAHWs for a few seconds seems to be an effective way.

Inactivation of human norovirus by chlorous acid water, a novel chlorine-based disinfectant.

INTRODUCTION: Human norovirus (HuNoV) is a leading cause of infectious gastroenteritis. Since HuNoV shows resistance to alcohol, chlorine-based sanitizers are applied to decontaminate the virus on environmental surfaces. Chlorous acid water (CA) has been recently approved as a novel chlorine-based disinfectant categorized as a Type 2 OTC medicine in Japan. In this study, we aimed to evaluate the capability of CA to inactivate HuNoV. METHODS: HuNoV (genogroups GII.2 and GII.4) was exposed to the test disinfectants including CA and sodium hypochlorite (NaClO), and the residual RNA copy was measured by reverse transcription quantitative PCR (RT-qPCR) after pretreatment with RNase. In addition, the log10 reduction of HuNoV RNA copy number by CA and NaClO was compared in the presence of bovine serum albumin (BSA), sheep red blood cells (SRBC), polypeptone, meat extract or amino acids to evaluate the stability of these disinfectants under organic-matter-rich conditions. RESULTS: In the absence of organic substances, CA with 200 ppm free available chlorine provided >3.0 log10 reduction in the HuNoV RNA copy number within 5 min. Even under high organic matter load (0.3% each of BSA and SRBC or 0.5% polypeptone), 200 ppm CA achieved >3.0 log10 reduction in HuNoV RNA copy number while less than 1.0 log10 reduction was observed with 1,000 ppm sodium hypochlorite (NaClO) in the presence of 0.5% polypeptone. CA reacted with only cysteine, histidine and glutathione while NaClO reacted with all of the amino acids tested. CONCLUSIONS: CA is an effective disinfectant to inactivate HuNoV under organic-matter-rich conditions.

Influence of soil amendment of different concentrations of amino acid water-soluble fertilizer on physiological characteristics, yield and quality of "Hangjiao No.2" Chili Pepper.

Amino acids are well known as natural stimulators of plant growth and are widely used to promote crop yield and quality. Several studies have been conducted to investigate the effects of amino acid (s) as a foliar spray on a variety of plant species. However, the effects of soil amendment of different concentrations of amino acid water-soluble fertilizer on the physiological characteristics, yield, and quality of pepper remain unclear. Following this, three experimental sets of amino acid water-soluble fertilizer in the ratio 1.8: 2.7: 3.6 kg including control (CK) were conducted in Lintao county, Gansu province. The treatments were applied through furrow method at 6 weeks after planting. The results showed that physiological characteristics of the pepper plants, such as chlorophyll a (1.35 mg g-1), and b (0.67 mg g-1), total chlorophyll (2.02 mg g-1), carotenoid (0.63 mg g-1), ETR (26.25 µmol m-2s-1), Fv/Fm (0.75), Qp (0.92) contents of the leaves were increased by the 1.8 kg treatment while NPQ (71.37%) and root activity (2185.52 µg g-1 h-1) were improved by the 3.6 kg treatment compared to the control. Fertilization with 2.7 kg of amino acid water-soluble fertilizer also had a significant influence on fruit length (25.50 cm), and yield of pepper (37.92 t ha-1) while fruit diameter (24.51 mm), firmness (5.30 kg cm-2), fresh (48.10 g) and dry (4.71 g) weights were higher in the 1.8 kg treatment compared to the control. The lowest rate of fertilizer (1.8 kg) applied again resulted in a significant increase in soluble protein (79.79%), capsaicin (5.80 mg g-1), dihydrocapsaicin (1.08 mg g-1), vitamin C (72.33%) and the essential and non-essential amino acid contents of the pepper which ranged from (235.15 to 11.16 µg g-1) and (1,605.10 to 16.63 µg g-1) respectively, while soluble sugar (9.02%) was enhanced by 3.6 kg treatment compared to the control. The findings suggest that soil amendment with low concentration of amino acid water-soluble fertilizer (1.8 kg) could be successfully used to improve the physiological characteristics and fruit quality of peppers in vegetable production.

Lignin dissolution model in formic acid-acetic acid-water systems based on lignin chemical structure.

The separation of lignin from woody biomass and subsequent conversion into useful products requires a solution to the problem of its solubility. The expanded C9 formula of lignin, along with its atomic and functional groups, was determined by elemental analysis and NMRs spectroscopy. Based on the thus-obtained expanded C9 formula, the cohesion parameters of lignin dispersion (10.8-11.1 cal1/2·cm-3/2), polarity (4.15-4.31 cal1/2·cm-3/2), hydrogen bonding (6.30-7.38 cal1/2·cm-3/2), and solubility (13.2-14.0 cal1/2·cm-3/2) were respectively calculated using atomic and functional group contributions method. We established the relationship between lignin structure and lignin solubility parameters. The dissolution characteristics of wheat straw organic acid lignin, industrial eucalyptus kraft lignin, bamboo kraft lignin, and softwood kraft lignin in formic acid-H2O, acetic acid-H2O, and formic acid-acetic acid-H2O solvent systems were analyzed. The results indicate that the dissolution behavior of lignins follows the solubility parameters theory. We have developed a lignin dissolution model according to the lignin structure. This model obeys the solubility parameter theory, overcomes the limitations of the "like dissolves like" principle in organic acid-water systems, and provides a concise method for the selection of lignin solvent systems and the quantitative determination of their solvent composition.

Virucidal activity of slightly acidic hypochlorous acid water toward influenza virus and coronavirus with tests simulating practical usage.

Slightly acidic hypochlorous acid waters (SAHWs) with pH of 5.2-5.8 containing different concentrations of free available chlorine - 62, 119, 220, 300, and 540 ppm (SAHW-62, -119, -220, -300, and -540, respectively) - were evaluated for their virucidal activity toward a low pathogenic H7N1 avian influenza virus (AIV) and an infectious bronchitis virus (IBV) in suspension, abiotic carrier, and direct spray tests, with the presence of organic materials. In the carrier test, the dropping and wiping techniques were performed toward viruses on carriers. In the suspension test, SAHW-62 could decrease the viral titer of both AIV and IBV by more than 1000 times within 30 s. With the dropping technique, IBV on carriers showed high resistance to SAHW, while AIV on plastic carrier was inactivated to an effective level (≧3 log virus reduction) within 1 min. With the wiping technique, SAHW-62 could inactivate both AIV and IBV on wiped plastic carriers to an effective level within 30 s. However, SAHW-220 could not inactivate IBV in the wiping rayon sheet to an effective level. In the direct spray test, sprayed SAHW-300 within 10 min, and SAHW-540 within 20 min, inactivated AIV and IBV on the rayon sheets to undetectable level, respectively. Our study indicates that the usage of wipes with SAHW could remove viruses from plastic carriers, while viruses remained in the wipes. Besides, a small volume of sprayed SAHW was effective against the viruses on the rayon sheets for daily cleaning in the application area. The findings we obtained concerning IBV might basically be applicable in relation to SARS-CoV-2, given the resemblance between the two viruses.

Citric Acid Water as an Alternative to Water Restriction for High-Yield Mouse Behavior.

Powerful neural measurement and perturbation tools have positioned mice as an ideal species for probing the neural circuit mechanisms of cognition. Crucial to this success is the ability to motivate animals to perform specific behaviors. One successful strategy is to restrict their water intake, rewarding them with water during a behavioral task. However, water restriction requires rigorous monitoring of animals' health and hydration status and can be challenging for some mice. We present an alternative that allows mice more control over their water intake: free home-cage access to water, made slightly sour by a small amount of citric acid (CA). In a previous study, rats with free access to CA water readily performed a behavioral task for water rewards, although completing fewer trials than under water restriction (Reinagel, 2018). We here extend this approach to mice and confirm its robustness across multiple laboratories. Mice reduced their intake of CA water while maintaining healthy weights. Continuous home-cage access to CA water only subtly impacted their willingness to perform a decision-making task, in which they were rewarded with sweetened water. When free CA water was used instead of water restriction only on weekends, learning and decision-making behavior were unaffected. CA water is thus a promising alternative to water restriction, allowing animals more control over their water intake without interfering with behavioral performance.

Synthesis of C-Plane Oriented Hexagonal Tungsten Oxide Membranes on Tubular Substrates and Their Acetic Acid/Water Separation Performances.

Hexagonal tungsten oxide (h-WO3) membrane is a novel candidate for dehydration of acetic acid (CH3COOH)/water mixtures owing to its molecular sieving property and acidic resistance. Meanwhile, c-plane orientation is an important factor for h-WO3 membranes because the pores of h-WO3 run along its c-axis. However, so far, high c-plane orientation has not been successful on tubular substrates. Here, the effect of synthesis conditions of h-WO3 membranes on tubular substrates against c-plane orientation and CH3COOH/water separation performance are investigated. The h-WO3 membranes were prepared by hydrothermal synthesis from a precursor sol containing various amounts of sodium tungstate (Na2WO4) in the presence of tubular substrates with seeds embedded on their outside surface. The seeding method and the amount of Na2WO4 in the precursor sol significantly affected both crystal orientation and densification of the membrane. A precursor sol with appropriate amounts of Na2WO4 was essential to simultaneously satisfy high c-plane orientation and densification of the membrane while excess Na2WO4 drastically decreased the degree of c-plane orientation. A highly c-plane oriented h-WO3 membrane was successfully obtained under the optimized condition, which exhibited a maximum separation factor of 40.0 and a water permeance of 1.53 × 10-7 mol·m-2·s-1·Pa-1 in a 90:10 wt % CH3COOH/water mixture. The water permeance approximately doubled compared to the previous report, possibly owing to the significantly higher degree of c-plane orientation. Furthermore, it was found that its separation ability can be maintained while stored in 90:10 wt % CH3COOH/water mixture with pH < 0 for more than 500 h.

Body cooling effects of immersion of the forearms in high-concentration artificial carbonic acid water at 25°C.

BACKGROUND: This study examined the effects of immersion in stirred, high-concentration, artificial carbonic acid water on body cooling. METHODS: Seven healthy male students (23 ± 2 years old) participated in the experiment. Signed informed consent was obtained from all subjects before the experiment. The subjects changed into shorts and T-shirts and entered an experimental room (with room temperature controlled at 30 °C and relative humidity maintained at 70%) at least 30 min before starting the experiment. After starting the experiment, the subjects were asked to rest on an exercise bike for 5 min and then pedal for 20 min. The exercise load was set to reach 50% of each subject's presumed maximum oxygen intake at 5 min after starting exercise. Subjects then continued pedaling for 1 min to cool down. After this exercise, subjects sat on a chair and immersed forearms in tap water or artificial carbonic acid water (CO2 water) at 25 °C for 20 min. During immersion, tap water or CO2 water was stirred slowly with a pump. After immersion, subjects rested for 10 min. Skin temperature and skin blood flow (left forearm), as well as heart rate and ear canal temperature, were measured continuously. Thermal sensation and thermal comfort were measured intermittently. RESULTS: Skin blood flow of the immersed forearms was higher in CO2 water than in tap water during immersion. The blood flow in the last 5 min (average at rest was 100%) was significantly higher in CO2 water (290.85 ± 84.81%) than in tap water (104.80 ± 21.99%). Thermal sensation and thermal comfort were not different between conditions. Ear canal temperature significantly declined more in CO2 water (- 0.56 ± 0.31 °C) than in tap water (- 0.48 ± 0.30 °C) during immersion. CONCLUSIONS: Our study suggests that immersion of the forearms in slowly stirred CO2 water at 25 °C reduces core temperature elevated by heat stress or exercise more effectively than does tap water at the same temperature. Immersion of the forearms in stirred CO2 water at 25 °C could be useful as a preventive measure against heat stroke from summer work or exercise.

Microbicidal effects of slightly acidic hypochlorous acid water and weakly acidified chlorous acid water on foulbrood pathogens.

Paenibacillus larvae and Melissococcus plutonius are bacterial pathogens of honey bee brood. As decontamination of beekeeping equipment, including combs, is essential to control these pathogens, we evaluated the disinfecting effects of slightly acidic hypochlorous acid water (SAHAW) and weakly acidified chlorous acid water (WACAW) on the pathogens. Both disinfectants exhibited strong disinfecting effects in suspension tests under no organic matter conditions and reduced both pathogens by >5 log10 CFU/ml. Although the microbicidal activity of SAHAW with an available chlorine concentration (ACC) of 10-30 ppm was decreased by organic matter, it reduced viable P. larvae spores in combs more efficiently than H2O when the comb was not as dirty. However, its efficacy on combs decreased at 4°C and when overused or highly contaminated combs were tested. WACAW with an ACC of ≥600 ppm had a higher disinfecting capacity than SAHAW, and efficiently removed P. larvae spores from combs even under organic matter-rich and low-temperature conditions. However, even by WACAW, the amount of viable spores in combs was not markedly reduced depending on contamination levels and P. larvae genotypes. These results suggest the usefulness of both disinfectants for decontaminating beekeeping equipment depending on the situations expected.

Study of molecular association in acetic acid-water binary solution by Raman spectroscopy.

Raman spectra of acetic acid-water binary solutions with different concentrations have been measured in order to study molecular association of acetic acid. We find that the symmetric and asymmetric OH stretching vibration of water (3242 and 3443 cm-1) have marked changes of Raman shift when the volume fraction of acetic acid (VAA) is 0.3 and 0.8, respectively, which demonstrates that the hydrogen bonding of the water is affected, causing association molecule (acetic acid-water structure) to undergo two phase transitions. Furthermore, the peak of the HCH bending vibration is blue-shifted at VAA = 0.8, which shows that the acetic acid-acetic acid structure undergoes a phase transition and the acetic acid side-on dimer is formed. These results also indicate that the CH vibration mode in CH⋯O is HCH bending vibration. Finally, the phase transition process of association molecules (hydrated monomer, linear dimer, acetic acid side-on dimer and water-separated dimer) has been obtained in acetic acid-water binary solutions through theoretical analysis.

Ion exchange at the critical point of solution.

A mixture of isobutyric acid (IBA)+water has an upper critical point of solution at 26.7°C and an IBA concentration of 4.40M. We have determined the Langmuir isotherms for the hydroxide form of Amberlite IRN-78 resin in contact with mixtures of IBA+water at temperatures, 27.0, 29.0, 31.0 and 38.0°C, respectively. The Langmuir plot at 38.0°C forms a straight line. At the three lower temperatures, however, a peak in the Langmuir plot is observed for IBA concentrations in the vicinity of 4.40M. We regard this peak to be a critical effect not only because it is located close to 4.40M, but also because its height becomes more pronounced as the temperature of the isotherm approaches the critical temperature. For concentrations in the vicinity of the peak, the data indicate that the larger isobutyrate ion is rejected by the resin in favor of the smaller hydroxide ion. This reversal of the expected ion exchange reaction might be used to separate ions according to size. Using the Donnan theory of ion exchange equilibrium, we link the swelling pressure to the osmotic pressure. We show that the peak in the Langmuir plot is associated with a maximum in the "osmotic" energy. This maximum has its origin in the concentration derivative of the osmotic pressure, which goes to zero as the critical point is approached.