Binding behavior of receptor binding domain of the SARS-CoV-2 virus and ivermectin.

The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), sparked an international debate on effective ways to prevent and treat the virus. Specifically, there were many varying opinions on the use of ivermectin (IVM) throughout the world, with minimal research to support either side. IVM is an FDA-approved antiparasitic drug that was discovered in the 1970s and was found to show antiviral activity. The objective of this study is to examine the binding behavior and rates of association and dissociation between SARS-CoV-2 receptor binding domain (RBD), IVM, and their combination using aminopropylsilane (APS) biosensors as surrogates for the hydrophobic interaction between the viral protein and human angiotensin-converting enzyme 2 (ACE2) receptors to determine the potential of IVM as a repurposed drug for SARS-CoV-2 prevention and treatment. The IVM, RBD, and combination binding kinetics were analyzed using biolayer interferometry (BLI) and validated with multiple in silico techniques including protein-ligand docking, molecular dynamics simulation, molecular mechanics-generalized Born surface area (MM-GBSA), and principal component analysis (PCA). Our results suggest that with increasing IVM concentrations the association rate with the hydrophobic biosensor increases with a simultaneous decrease in dissociation. Significant kinetic changes to RBD, when combined with IVM, were found only at a concentration a thousand times the approved dosage with minimal changes found over a 35-min time period. Our study suggests that IVM is not an effective preventative or treatment method at the currently approved dosage.

Effects of Chalcogen Atoms on Excited-State Double-Proton Transfer Behavior for 3,6-bis(4,5-Dihydroxyoxazo-2-yl)benzene-1,2-diol Derivatives: A Computational Investigation.

The impact of the chalcogen atomic electronegativity (O, S, and Se atoms) of new organic molecules on excited-state dynamical reactions is self-evident. Inspired by this kind of distinguished photochemical characteristic, in this work, we performed a computational investigation of chalcogen-substituted 3,6-bis(4,5-dihydroxyoxazo-2-yl)benzene-1,2-diol (BDYBD) derivatives (i.e., BDYBD-O, BDYBD-S, and BDYBD-Se). In this paper, we pay close attention to characteristic BDYBD derivatives that contain intramolecular double hydrogen bonds (O1-H2···N3 and O4-H5···N6). The main goal of this study was to explore how changes in atomic electronegativity affect the way hydrogen bonds interact and how excited molecules affect transfer protons. We go into further detail in the main text of the paper. By fixing our attention to geometrical variations and infrared (IR) vibrational spectra between the S0 and S1 states, exploring hydrogen bonding behaviors using the core-valence bifurcation (CVB) index, and simulating hydrogen bonding energy (EHB) via the atom in molecule (AIM) method, we clarified the photo-induced strengthened dual hydrogen bonding interactions that facilitate the excited-state dual-proton transfer (ESDPT) behavior of BDYBD derivatives. The reorganization of charge stemming from photoexcitation further verifies the tendencies of ESDPT reactions. We relied on constructing potential energy surfaces (PESs) by adopting a restrictive optimization approach, and herein, we finally clarify the gradual ESDPT mechanism of BDYBD derivatives. Particularly, we confirm that the variation in chalcogen atomic electronegativity has a regulatory effect on the ESDPT behavior of BDYBD derivatives; that is, the lower the atomic electronegativity, the more favorable it is for the gradual ESDPT reaction.

Incorporation of Selenium Derived from Nanoparticles into Plant Proteins in Vivo.

Diets comprising selenium-deficient crops have been linked to immune disorders and cardiomyopathy. Selenium nanoparticles (SeNPs) have emerged as a promising nanoplatform for selenium-biofortified agriculture. However, SeNPs fail to reach field-scale applications due to a poor understanding of the fundamental principles of its behavior. Here, we describe the transport, transformation, and bioavailability of SeNPs through a combination of in vivo and in vitro experiments. We show synthesized amorphous SeNPs, when sprayed onto the leaves of Arabidopsis thaliana, are rapidly biotransformed into selenium(IV), nonspecifically incorporated as selenomethionine (SeMet), and specifically incorporated into two selenium-binding proteins (SBPs). The SBPs identified were linked to stress and reactive oxygen species (mainly H2O2 and O2-) reduction, processes that enhance plant growth and primary root elongation. Selenium is transported both upwards and downwards in the plant when SeNPs are sprayed onto the leaves. With the application of Silwet L-77 (a common agrochemical surfactant), selenium distributed throughout the whole plant including the roots, where pristine SeNPs cannot reach. Our results demonstrate that foliar application of SeNPs promotes plant growth without causing nanomaterial accumulation, offering an efficient way to obtain selenium-fortified agriculture.

Temporal Variation of SARS-CoV-2 Levels in Wastewater from a Meat Processing Plant.

Wastewater-based surveillance (WBS) on SARS-CoV-2 has been proved to be an effective approach to estimate the prevalence of COVID-19 in communities and cities. However, its application was overlooked at smaller scale, such as a single facility. Meat processing plants are hotspots for COVID-19 outbreaks due to their unique environment that are favorable for the survival and persistence of SARS-CoV-2. This is the first known WBS study in meat processing plants. The goal was to understand the temporal variation of the SARS-CoV-2 levels in wastewater from a meat processing plant in Canada during a three-month campaign and to find any correlation with clinically confirmed cases in the surrounding city area. Higher SARS-CoV-2 concentrations and detection frequencies were observed in the solid fraction compared to the liquid fraction of the wastewater. The viruses can be preserved in the solid fraction of wastewater for up to 12 days. The wastewater virus level did not correlate to the city-wide COVID-19 cases due to the unmatching scales. WBS on SARS-CoV-2 in meat processing plants can be useful for identifying COVID-19 outbreaks in the facility and serve as an effective alternative when resources for routine individual testing are not available.

Occurrence and influencing factors of antibiotics and antibiotic resistance genes in sediments of the largest multi-habitat lakes in Northern China.

Baiyangdian Lake is a typical and largest multi-habitat lake in the North plain of China. To understand the generation and transmission of antibiotics resistance genes (ARGs) in multi-habitat lakes, the contents of nutrients (TC, TOC, TN, TP and TS), heavy metals (Zn, Cr, Ni, Cu, Pb, As, Cd and Hg), 22 antibiotics, 16S-rRNA(16S), Class I integron (intI1) and 20 ARGs were determined. Samples were taken from the Fuhe river, river estuaries, reed marshes, living area, fish ponds and open water of Baiyangdian Lake. The results showed that quinolones were the main pollutants in six habitats, and the content range was ND-104.94 ng/g. Thereinto, aac (6') -IB, blaTEM-1, ermF, qnrA, qnrD, tetG, sul1, sul2 and tetM were detected in all the analyzed samples. The absolute abundance of sul1 was the highest (5.25 × 105 copies/g-6.21 × 107 copies/g) in most of the samples. In these different habitats, the abundance of antibiotics and ARGs in river estuary was the highest, and that in reed marshes was the lowest. There was a significant positive correlation between the abundance of heavy metals (Cu, Pb, Zn, Ni, Cd, Hg) and the absolute abundance of 11 ARGs (P < 0.01). Redundancy analysis showed that Cu, Zn, intI1, TP and macrolides were the important factors affecting the distribution of ARGs. Our finding provides a more likely driving and influencing factor for the transmission of ARGs in lakes with complex and diverse habitats.

Evaluation of the Potential Protective Effects of Lactobacillus Strains against Helicobacter pylori Infection: A Randomized, Double-Blinded, Placebo-Controlled Trial.

Background: The beneficial effects of probiotic supplementation standard antibiotic therapies for Helicobacter pylori infection have been verified, but the ability of probiotic monotherapy to eradicate H. pylori remains unclear. Aim: To evaluate the accuracy and efficacy of specific Lactobacillus strains against H. pylori infection. Methods: Seventy-eight patients with H. pylori infection were treated with strain L. crispatus G14-5M (L. crispatus CCFM1118) or L. helveticus M2-09-R02-S146 (L. helveticus CCFM1121) or L. plantarum CCFM8610 at a dose of 2 g twice daily for one month. 14C-urea breath test, the gastrointestinal symptom rating scale, serum pepsinogen concentrations, and serum cytokine concentrations of patients were measured at baseline and end-of-trial to analyze the effect of the Lactobacillus strains in eradicating H. pylori infection and reducing gastrointestinal discomfort in patients. In addition, the composition and abundance of the intestinal microbiota of patients were also measured at end-of-trial. Results: The 14C-urea breath test value of the three Lactobacillus treatment groups had decreased significantly, and the eradication rate of H. pylori had increased by the end of the trial. In particular, the eradication rate in the G14-5M treatment group was significantly higher than the placebo group (70.59% vs. 15.38%, P=0.0039), indicating that one-month administration of the G14-5M regimen was sufficient to eradicate H. pylori infection. The ingestion of Lactobacillus strains also ameliorated the gastrointestinal symptom rating scale scores, and the serum interleukin-8 concentrations of H. pylori-infected patients appeared to modulate the gut microbiota of patients. However, none of the Lactobacillus strains had a significant effect on general blood physiological characteristics, serum tumor necrosis factor α concentrations, or serum pepsinogen concentrations in the patients. Conclusion: Three Lactobacillus strains significantly alleviate the gastrointestinal discomfort and the gastric inflammatory response of H. pylori-infected patients. The activity of probiotics in eradicating H. pyloriinfection may be species/strain specific.

Effect of Multimedia Health Education on Psychological Burden, Quality of Life Ability, and Self-Efficacy of Congenital Microtia.

Aims: To investigate the effects of multimedia health education on psychological burden, quality of life, and self-efficacy of patients with congenital microtia. Materials and Methods: Eighty cases of patients with congenital microtia treated and cared for in our hospital from June 2018 to June 2022 were selected according to the numerical table method as retrospective study subjects and divided into 40 cases each in the comparison group and the observation group. The comparison group implemented conventional health education and discharge instruction, and the observation group implemented multimedia health education care to compare the effects of self-efficacy, self-care ability and psychological burden of patients in the two groups. Results: Before care, the two groups had no statistically significant difference in the quality of life scores (P > 0.05). Aftercare, the mental vitality scores, social interaction scores, emotional limitation scores, and mental status of patients in the observation group were significantly higher than those in the comparison group (P < 0.05). Before nursing care, there was no statistically significant difference in the nursing ability and anxiety-depression scores between the two groups (P > 0.05). After nursing care, the health knowledge level, self-care skills, self-care responsibility, and self-concept of the observation group were higher than the comparison group, while the depression-emotional disorder scores were significantly lower than the comparison group (P < 0.05). Conclusion: Routine health education and discharge instruction combined with multimedia health education care can effectively improve the quality of life of patients with congenital microtia, reduce adverse emotions, and improve patients' sense of self-efficacy.

Environmental Effects on Viable Virus Transport and Resuspension in Ventilation Airflow.

To understand how SARS-CoV-2 spreads indoors, in this study bovine coronavirus was aerosolized as simulant into a plexiglass chamber with coupons of metal, wood and plastic surfaces. After aerosolization, chamber and coupon surfaces were swiped to quantify the virus concentrations using quantitative polymerase chain reaction (qPCR). Bio-layer interferometry showed stronger virus association on plastic and metal surfaces, however, higher dissociation from wood in 80% relative humidity. Virus aerosols were collected with the 100 L/min wetted wall cyclone and the 50 L/min MD8 air sampler and quantitated by qPCR. To monitor the effect of the ventilation on the virus movement, PRD1 bacteriophages as virus simulants were disseminated in a ¾ scale air-conditioned hospital test room with twelve PM2.5 samplers at 15 L/min. Higher virus concentrations were detected above the patient's head and near the foot of the bed with the air inlet on the ceiling above, exhaust bottom left on the wall. Based on room layout, air measurements and bioaerosol collections computational flow models were created to visualize the movement of the virus in the room airflow. The addition of air curtain at the door minimized virus concentration while having the inlet and exhaust on the ceiling decreased overall aerosol concentration. Controlled laboratory experiments were conducted in a plexiglass chamber to gain more insight into the fundamental behavior of aerosolized SARS-CoV-2 and understand its fate and transport in the ambient environment of the hospital room.

[Pollution Characteristics and Risk Assessment of Nutrients and Heavy Metals in Sediments of the Fuhe River Influenced Area, Baiyangdian Lake].

Based on the flow direction of the Fuhe River into Baiyangdian Lake, the impacted area of the Fuhe River was divided into 6 subareas, and sediments from 48 sites were collected in November 2020. The characteristics and risks of sediment nutrients and heavy metal pollution in these six subareas were investigated. The results showed that the average ω(TN), ω(TP), and ω(TOC) were 1841 mg·kg-1, 769 mg·kg-1, and 1.77%, respectively. The major heavy metals were Cd, Cu, Zn, Hg, and Pb, which were 3.73, 1.50, 1.42, 1.31, and 1.31 times the soil background values for Hebei Province, respectively. The TP and heavy metal (Cd, Cu, Zn, Hg, and Pb) content showed a decreasing trend from the Fuhe River estuary to the downstream Zaolinzhuang, whereas the TN and TOC content showed no marked trends. TN, TP, TOC, and heavy metals (Cd, Cu, Zn, Hg, and Pb) were enriched in surface sediments (0-10 cm). The TP content in the surface sediments (0-10 cm) of the Fuhe River estuary, Fuhe River estuary-Nanliuzhuang, and Nanliuzhuang subareas were heavily polluted; the Wangjiazhai and Guangdian subareas were moderately polluted; and the Zaolinzhuang subarea was slightly polluted. Cd and Hg were the major contributors to heavy metal pollution, which were at considerable risk and moderate risk levels, respectively. The heavy metals in surface sediments (0-10 cm) of the Fuhe River estuary, Fuhe River estuary-Nanliuzhuang, and Nanliuzhuang subareas were at a considerable risk level, and the sediments below 30 cm presented a low risk level. The leaching concentrations of heavy metals in sediments from the subarea of severe ecological risk level were far less than the identification standard values of leaching toxicity, suggesting that the sediments can be treated as general waste after dredging.

Binding behavior of spike protein and receptor binding domain of the SARS-CoV-2 virus at different environmental conditions.

A novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified as the cause of the COVID-19 pandemic that originated in China in December 2019. Although extensive research has been performed on SARS-CoV-2, the binding behavior of spike (S) protein and receptor binding domain (RBD) of SARS-CoV-2 at different environmental conditions have yet to be studied. The objective of this study is to investigate the effect of temperature, fatty acids, ions, and protein concentration on the binding behavior and rates of association and dissociation between the S protein and RBD of SARS-CoV-2 and the hydrophobic aminopropylsilane (APS) biosensors using biolayer interferometry (BLI) validated with molecular dynamics simulation. Our results suggest three conditions-high ionic concentration, presence of hydrophobic fatty acids, and low temperature-favor the attachment of S protein and RBD to hydrophobic surfaces. Increasing the temperature within an hour from 0 to 25 °C results in S protein detachment, suggesting that freezing can cause structural changes in the S protein, affecting its binding kinetics at higher temperature. At all the conditions, RBD exhibits lower dissociation capabilities than the full-length S trimer protein, indicating that the separated RBD formed stronger attachment to hydrophobic surfaces compared to when it was included in the S protein.

The spatial variations of water quality and effects of water landscape in Baiyangdian Lake, North China.

Baiyangdian Lake (BYD), a large shallow lake in North China, has complex water landscape patterns that are underlies spatial variations in water quality. In this study, we collected 61 water samples from three water landscapes (reed littoral zones, fish ponds, and open water) and analyzed them for water quality parameters, such as dissolved organic carbon (DOC), total nitrogen (TN), and total phosphorus (TP). Water landscape distribution (determined using remote sensing imagery) was then used to assess correlations between water quality parameters and water landscape proportion in differently scaled buffer zones. There was substantial variation across all subareas, with TN and TP concentrations ranging from 0.90 to 4.10 mg/L and 0.06 to 0.18 mg/L, respectively, in class IV of water quality as a whole. Spatial variations in water quality were mainly caused by water landscape distribution and external nutrient inputs. There were negative correlations between DOC, TN, and TP concentrations and the area proportion of reed littoral zones in the 300 and 500 m buffers. In contrast, DOC, TN, and TP concentrations were significantly positively correlated with the area proportion of fish ponds in the 100 m buffer. Furthermore, compared with reed littoral zones, a lower ratio of nitrogen to phosphorus and a higher proportion of dissolved organic nitrogen and tyrosine-like proteins were found in fish ponds. These effects were mainly attributed to the development of internal sediment loadings due to nutrient exchange across the sediment-water interface. Therefore, dredging-based sediment removal from fish ponds should be considered to suppress internal phosphorus loading and accelerate recovery of the BYD ecosystem.

Utilization of coal fly ash waste for effective recapture of phosphorus from waters.

Reutilization of the waste by-products from industrial and agricultural activities is crucially important towards attainment of environmental sustainability and the 'circular economy'. In this study, we have developed and evaluated a sustainably-sourced adsorbent from coal fly ash, which was modified by a small amount of lanthanum (La-FA), for the recapture of phosphorous (P) from both synthetic and real natural waters. The prepared La-FA adsorbent possessed typical characteristic diffraction peaks similar to zeolite type Na-P1, and the BET surface area of La-FA was measured to be 10.9 times higher than that of the original FA. Investigation of P adsorption capability indicated that the maximum adsorption (10.8 mg P g-1) was 6.14 times higher than that (1.8 mg P g-1) of the original fly ash material. The ζ potentials measurement and P K-edge X-ray Absorption Near Edge Structure (XANES) spectra demonstrated that P was bonded on La-FA surfaces via an adsorption mechanism. After applying the proposed adsorbent to real lake water with La/P molar ratios in the range from 0.5:1 to 3:1, the La-FA adsorbent showed the highest phosphate removal ability with a La/P molar ratio 1:1, and the P adsorption was similar to that performance with the synthetic solution. Moreover, the La-FA absorbent produced a negligible effect on the concentrations of total dissolved nitrogen (TDN), NH4+-N and NO3--N in water. This study thus provides a potential material for effective P recapture and details of its operation.

[Distribution Characteristics and Risk Assessment of Antibiotics and Polycyclic Aromatic Hydrocarbons in the Sediments of Desilting Demonstration Area in Baiyangdian Lake].

A total of 22 antibiotics and 16 polycyclic aromatic hydrocarbons(PAHs) in sediments before and after desilting in typical areas(fish ponds and open water) of Baiyangdian Lake were analyzed using HPLC-MS/MS and GC/MS(high performance liquid chromatography and gas chromatography coupled with mass spectrometry), to evaluate their potentially risks to the ecological environment. The results showed that the contents of 22 antibiotics in Baiyangdian Lake sediments ranged from 0 to 52.89 ng·g-1, in which the quinolones content was the highest. After dredging treatment, the average content of antibiotics in Nanliuzhuang open water area decreased from 46.25 ng·g-1 to 9 ng·g-1(80.54% reduction), while the average content of antibiotic(19.07 ng·g-1) in Caiputai remained relatively stable. Therefore, the dredging treatment performed better in removing antibiotics from Naliuzhuang area. The total contents of 16 PAHs in sediments ranged from 23.79 ng·g-1 to 329.40 ng·g-1, in which Naphthalene was the highest(242.02 ng·g-1), while Fluoranthene was the lowest. The average content of PAHs in sediments in Nanliuzhuang decreased from 117.45 ng·g-1 to 50.49 ng·g-1 after dredging, while PAHs in Caiputai(57.98 ng·g-1) remained stable; the 57.01% reduction in PAHs in Nanliuzhuang open water indicated that dredging treatment exhibited stronger effects on PAHs variations in Nanliuzhuang compared to that of Caiputai. In addition, the ecological risk assessment showed that the risk of Enrofloxacin and Norfloxacin was high in area S2 of Nanliuzhuang open water, while PAHs exhibited relatively low ecological risk, in which the Naphthalene in area S1 of Fuhe river posed medium ecological risk while the remaining produced low ecological risks. The results indicated that quinolone antibiotics in sediments of the un-dredged area of Baiyangdian Lake should be monitored due to its higher ecological risk.

[Identification of Dredging Depths Based on Sediment Vertical Distribution Profiles of Total Nitrogen and Total Phosphorus and Their Adsorption-desorption Equilibria].

A dredging demonstration project in the Baiyangdian Lake included open waters and fishing ponds to reduce the internal release of nitrogen and phosphorus from bottom sediments. The dredging depth design was determined by both the sediment vertical distribution profile of total nitrogen and phosphorus, and the sediment adsorption-desorption equilibrium method. The determined dredging depths were very similar and coincident. The dredging depth for the demonstration area of open waters in Nanliuzhuang was identified as(50±10) cm; and the dredging depths for fishing ponds were(30±10) cm in both the Nanliuzhuang and Caiputai demonstration areas. The equilibrium nitrogen(NH4+-N) and phosphorus(SRP) concentrations at zero net sorption or desorption(ENC0 and EPC0) were significantly positively correlated with both exchangeable and total nitrogen and phosphorus in the sediments. The total nitrogen and phosphorus in the sediments were also used to predict the risk of their release from the bottom sediments to the overlying water column. The sediment layers with ENC0 and EPC0 values greater than the NH4+-N and SRP in the overlying water column indicated the sediments act as a source of dissolved nitrogen and phosphorus to the overlying water column in the Nanliuzhuang and Caiputai demonstration areas. Accordingly, the sediment layers with both total nitrogen concentrations greater than 750 mg·kg-1 and total phosphorus concentrations greater than 500 mg·kg-1 should be identified as dredging layers.

Reducing arsenic toxicity using the interfacial oxygen nanobubble technology for sediment remediation.

The arsenic (As)-bearing eutrophic waters may suffer from the dual conditions of harmful algal blooms and release of As, driven by algal-induced hypoxia/anoxia. Here, we investigate the use of interfacial oxygen (O2) nanobubble technology to combat the hypoxia and control As exposure in simulated mesocosm experiments. It was observed that remediation of algal-induced hypoxia at the sediment-water interfaces (SWI) by application of O2 nanobubbles reduced the level of dissolved As from 23.2 µg L-1 to <10 µg L-1 and stimulated the conversion of As(III) to the less toxic As(V) (65-75%) and methylated As (10-15%) species. More than half of the oxidation and all the methylation of As(III) resulted from the manipulation by O2 nanobubbles of microbes responsible for As(III) oxidation and methylation. Hydroxyl radicals were generated during the oxidation of reductive substances at the SWI in darkness, and should be dominant contributors to As(III) abiotic oxidation. X-ray absorption near-edge structure (XANES) spectroscopic analysis demonstrated that surface sediments changed from being sources to acting as sinks of As, due to the formation of Fe-(hydr)oxide. Overall, this study suggests that interfacial O2 nanobubble technology could be a potential method for remediation of sediment As pollution through the manipulation of O2-related microbial and geochemical reactions.

Molecular level study of cadmium adsorption on dithiocarbamate modified chitosan.

It has been shown that chemical modification of chitosan with sulfur (S) functional groups could significantly enhance its chelating capability with heavy metals included Cd(II). However, a molecular level understanding has been lacking. Here, we carried out X-ray absorption fine structure (XAFS) and Fourier transformed infrared (FTIR) spectra studies to bridge this knowledge gap. The results indicate that both Cd-O/N and Cd-S bonds exist in the complex of Cd(II) with dithiocarbamate chitosan (DTC-CTS). S functional groups (dithiocarbamate) in DTC-CTS play the major role in complexation with Cd(II) and S content affects the adsorption mechanism. At low S content, Cd(II) is mainly adsorbed on DTC-CTS as an outer-sphere complex with two monodentate amino groups and two water molecules in tetrahedral configuration. At high S content, Cd adsorption dominantly occurs by formation of an inner-sphere complex with two bidentate mononuclear S ligands in tetrahedral configuration. This investigation provides information on the effectiveness and mechanisms of Cd(II) removal that is critical for evaluating modified chitosan applications for stabilization of Cd(II) in surface water, groundwater, soils and sediments.

Meta-analysis of the efficacy of probiotic-supplemented therapy on the eradication of H. pylori and incidence of therapy-associated side effects.

Traditional therapies for Helicobacter pylori (H. pylori) infection remain hindered by the antibiotic resistance of the pathogen and the poor therapeutic compliance of patients. To address these issues, probiotics have been added as an adjunctive therapy. This meta-analysis aimed to evaluate the efficacy of probiotic supplementation during standard therapy on the eradication rate of H. pylori infection and incidence of therapy-related side effects. Four online databases were searched for eligible studies without language restriction. Review Manager (REVMAN, Version 5.3) was used to perform all data analyses. Forty articles including 5792 patients met our criteria and were included in the analysis. Notably, probiotic supplementation improved the eradication rate by approximately 10% relative to the control group [odds ratio (OR), 1.94, 95% confidence interval (CI): 1.70-2.22, P < 0.00001]. The incidence of total side effects (OR, 0.56, 95% CI: 0.45-0.70, P < 0.00001) and individual symptoms (e.g., diarrhea, vomiting and nausea, constipation, epigastric pain, taste disturbance) also decreased significantly with probiotic supplementation. No other differences in side effects were observed between the experimental and control groups. Moreover, a longer duration (≥10 days) of probiotic treatment had positive effects on both eradication rate of H. pylori and incidence of overall side effects.

Molecular-level investigations of effective biogenic phosphorus adsorption by a lanthanum/aluminum-hydroxide composite.

Biogenic phosphorus (P), such as organic P and inorganic pyrophosphates, could substantially contribute towards eutrophication in aquatic systems by internal loading of P from sediment through P species transformation. Previous eutrophication management studies mainly focus on the removal of orthophosphate (Ortho-P), however, an effective approach for biogenic P control from water sources, prior to incorporation in sediment, is still lacking. In this study, a lanthanum/aluminum-hydroxide (LAH) composite was demonstrated to provide both superior removal of Ortho-P and biogenic P, employing myo-inositol hexakisphosphate (IHP) and pyrophosphate (Pyro-P) as model compounds. The maximum IHP and Pyro-P adsorption capacities by LAH attained 36.4 and 21.8 mg P g-1, respectively. In order to understand the mechanisms of adsorption, zeta potential, 31P solid-state nuclear magnetic resonance (NMR) spectroscopy and P K-edge X-ray absorption near edge structure (XANES) techniques were used to characterize the LAH after adsorption. The results supported the hypothesis that the interaction between LAH and P species was through surface adsorption, by the formation of inner-sphere complexes. Linear combination fitting results of XANES data indicated that IHP and Pyro-P preferentially bonded with La-hydroxide in LAH. This study elucidates the adsorption properties and binding mechanisms of IHP and Pyro-P on lanthanum-bearing compounds at the molecular level, indicating that LAH is a promising material for the control of eutrophication.

Mitigation of methylmercury production in eutrophic waters by interfacial oxygen nanobubbles.

In mercury (Hg)-polluted eutrophic waters, algal blooms are likely to aggravate methylmercury (MeHg) production by causing intensified hypoxia and enriching organic matter at the sediment-water interface. The technology of interfacial oxygen (O2) nanobubbles is proven to alleviate hypoxia and may have potential to mitigate the risks of MeHg formation. In this study, incubation column experiments were performed using sediment and overlying water samples collected from the Baihua Reservoir (China), which is currently suffering from co-contamination of Hg and eutrophication. The results indicated that after the application of O2 nanobubbles, the %MeHg (ratio of MeHg to total Hg) in the overlying water and surface sediment decreased by up to 76% and 56% respectively. In addition, the MeHg concentrations decreased from 0.54 ± 0.15 to 0.17 ± 0.01 ng L-1 in the overlying water and from 56.61 ± 9.23 to 25.48 ± 4.08 ng g-1 in the surface sediment. The decline could be attributed to the alleviation of anoxia and the decrease of labile organic matter and bioavailable Hg. In addition, hgcA gene abundances in the overlying water and surface sediment decreased by up to 69% and 44% after the addition of O2 nanobubbles, as is consistent with MeHg occurrence in such areas. Accordingly, this work proposed a promising strategy of using interfacial oxygen nanobubbles to alleviate the potentially enhanced MeHg production during algal bloom outbreaks in Hg-polluted eutrophic waters.

Highly efficient and irreversible removal of cadmium through the formation of a solid solution.

Sulfur-containing materials are very attractive for the efficient decontamination of some heavy metals. However, the effective and irreversible removal of Cd2+, coupled with a high uptake efficiency, remains a great challenge due to the relatively low bond dissociation energy of CdS. Herein, we propose a new strategy to overcome this challenge, by the incorporation of Cd2+ into a stable ZnxCd1-xS solid solution, rather than into CdS. This can be realised through the adsorption of Cd2+ by ZnS nanoparticles, which have exhibited a Cd2+ uptake capacity of approximate 400 mg g-1. Through this adsorption mechanism, the Cd2+ concentration in a contaminated solution could effectively be reduced from 50 ppb to <3 ppb, a WHO limit acceptable for drinking water. In addition, ZnS continued to exhibit this noteworthy uptake capacity even in the presence of Cu2+, Pb2+, and Hg2+. ZnS displayed high chemical stability. Particles aged in air for 3 months still retained a> 80% uptake capacity for Cd2+, compared with only 9% uptake capacity for similarly-aged FeS particles. This work reveals a new mechanism for Cd2+ removal with ZnS and establishes a valuable starting point for further studies into the formation of solid solutions for hazardous heavy metal removal applications.