[Determination of individual components in finished motor gasoline by dual-channel three-column gas chromatography].

A method based on a dual-channel gas chromatograph equipped with three columns and three detectors was established for the determination of individual components in finished motor gasoline. The gasoline samples were separately introduced into the two injection ports of the chromatograph using two autosamplers. The components of the sample introduced into the first injection port (channel 1) were separated on a nonpolar PONA column (50 m×0.20 mm×0.5 µm) for gasoline analysis and detected by an flame ionization detector (FID). The components of the sample introduced into the second injection port (channel 2) were separated on another PONA column. Oxygenates (e.g., ethers and alcohols), other unconventional and prohibited additives that would co-elute with the hydrocarbons (e.g., methylal, dimethyl carbonate, sec-butyl acetate, and anilines), and some difficult-to-separate hydrocarbon pairs (e.g., 2,3,3-trimethylpentane and toluene) eluted from the PONA column and entered a DM-624 column (30 m×0.25 mm×1.4 µm) to achieve further separation according to the switch timetable using the Deans switch procedure and detected by an FID. The peak of 3-methylpentane, a common component in gasoline samples, also entered the DM-624 column by the Deans switch procedure for calculation purposes. The peak areas of target components on the PONA column in channel 1 were calculated using the peak areas on the DM-624 column as well as those of 3-methylpentane on both the DM-624 and PONA columns in channel 1 with a calibration factor between the two channels. The peak areas of co-eluted components were obtained by subtracting the calculated peak areas of the target components from those of the co-eluted peaks. The mass percentages of the individual components were calculated according to the normalization method using all peak areas on the PONA column in channel 1 with relative response factors. The mass percentages of the oxygenates, anilines, and individual hydrocarbons were determined, and the group-type distribution was calculated according to the carbon number. Separation and quantitation interferences between the additives and hydrocarbons were eliminated using this procedure. Twenty oxygenates and unconventional additives, each with a mass percentage of approximately 3%, were added to a real motor gasoline-92 sample and analyzed using the proposed method. The recoveries of the target components were between 90.1% and 118.2% with relative standard deviations (RSDs) between 0.2% and 5.1% (n=6). The analysis of a real ethanol-gasoline sample showed that the RSDs of contents of most components was less than 3% (n=6). Because the heart-cut of peaks using Deans switch technique requires the precise repeatability of retention times, the retention-time repeatability of components on the PONA column in channel 2 was investigated over an extended period of time after thousands of runs of real-sample analysis. The retention times of the same component in several randomly selected motor gasoline-92 samples varied from 0.01 to 0.03 min, indicating that the proper timetable for the Deans switch remained stable for two years. The precise repeatability of retention times was achieved owing to the high precision of the electric pneumatic control of the chromatograph and the stability of the column used. Real finished motor gasoline samples with different octane numbers (gasoline-92, gasoline-95, and ethanol gasoline-95) were analyzed using the developed method, and the results acquired were consistent with those of standard methods (GB/T 30519-2016, NB/SH/T 0663-2014, and SH/T 0693-2000). If some unconventional additives (such as methylal) were added to gasoline samples, the contents of these unconventional additives could also be detected, which means one run of the proposed method could provide results corresponding to three or four runs of different standard methods. The acquisition of information on the individual components of finished motor gasoline will assist in research on precise gasoline blending.

The role of the SIRT1/NF-κB/NLRP3 pathway in the pyroptosis of lens epithelial cells under shortwave blue light radiation.

Cataracts are the world's number one blinding eye disease. Cataracts can only be effectively treated surgically, although there is a chance of surgical complications. One of the pathogenic processes of cataracts is oxidative stress, which closely correlated with pyroptosis. SIRT1 is essential for the regulation of pyroptosis. Nevertheless, the role of SIRT1 in formation of cataracts is unclear. In this work, we developed an in vitro model of shortwave blue light (SWBL)-induced scotomization in human lens epithelial cells (HLECs) and an in vivo model of SWBL-induced cataracts in rats. The study aimed to understand how the SIRT1/NF-κB/NLRP3 pathway functions. Additionally, the evaluation included cell death and the release of lactate dehydrogenase (LDH), a cytotoxicity marker, from injured cells. First, we discovered that SWBL exposure resulted in lens clouding in Sprague- Dawley (SD) rats and that the degree of clouding was positively linked to the duration of irradiation. Second, we discovered that SIRT1 exhibited antioxidant properties and was connected to the NF-κB/NLRP3 pathway. SWBL irradiation inhibited SIRT1 expression, exacerbated oxidative stress, and promoted nuclear translocation of NF-κB and the activation of the NLRP3 inflammasome, which caused LEC pyroptosis and ultimately led to cataract formation. Transient transfection to increase the expression of SIRT1 decreased the protein expression levels of NF-κB, NLRP3, caspase-1, and GSDMD, inhibited HLEC pyroptosis, and reduced the release of LDH, providing a potential method for cataract prevention and treatment.

Protection of Omicron Sub-Lineage Infection Against Reinfection with Another Omicron Sub-Lineage: Systematic Review, Meta-Analysis, and Meta-Regression - Worldwide, 2022-2023.

What is already known about this topic?: Both the decline in immunity over time and the evolution of the virus play a role in the level of protection offered by a prior infection. What is added by this report?: Point estimates indicated variations in protection levels based on the initial infecting variant and the reinfecting variant. There was a consistent correlation between real-world protection, antigenic distance, and humoral immunity levels. Specifically, shorter antigenic distances and higher humoral immunity levels corresponded to enhanced real-world protection. What are the implications for public health practice?: Our findings suggest that virological and immunological studies could help identify and assess the epidemic risk posed by new variants before they become dominant. Prompt incorporation of the latest variants into the antigen components of the coronavirus disease 2019 (COVID-19) vaccines can significantly contribute to effective epidemic prevention and control measures.

Visualizing Single-Molecule Protein Conformational Transitions and Free Energy Landscape.

Monitoring the conformational dynamics of individual proteins is essential to understand the relationship between structure and function in molecular regulatory mechanisms. However, the fast dynamics of single proteins remain poorly understood. Here, we construct a single-molecule sensing platform by introducing plasmonic imaging of single nanoparticles to sense and report the protein conformational changes at the single-molecule level. Tracking the fluctuations of individual nanoparticles with high resolution, we detect and characterize distinct conformational states of molecular chaperone heat shock protein 90 (Hsp90). We also explore the conformational changes of Hsp90 in situ under different nucleotide conditions. Analysis of the conformational fluctuations between the open and closed states of single Hsp90 provides important information on free energy profiles, effective spring constants, and multiphase behaviors. This method offers a strategy to visualize the conformational changes of single proteins in real-time and provides insights into the underlying molecular mechanisms.

Construction of Cell Membrane Chromatography Screening Materials Based on Avi-Tag Fused G Protein-Coupled Receptors.

Mas-related G protein-coupled receptor X2 (MrgprX2) plays a crucial role in anaphylactoid reactions and allergic diseases. Some antagonists with reasonable potency and selectivity have been reported. Cell membrane chromatography (CMC) is effective for discovering ligands. Protein-tag-based CMC models (e.g., SNAP tags and HALO tags) have enhanced performance but also increased nonspecific adsorption of small molecules. The Avi tag, a short peptide sequence, binds biotin specifically via BirA catalysis. Our study showed that 2-iminobiotin (IB) can be a BirA substrate, enabling the development of a new cell membrane stationary phase (CMSP) based on the chemical properties (modifying carboxyl silica gel and specifically labeling the Avi tag) of IB. First, we constructed the MrgprX2-Avi-tag HEK293T cell line. Next, we synthesized IB-modified silica gel (SiO2-IB) stepwise. Finally, we immobilized Avi-tagged MrgprX2 cell membranes on SiO2-IB under BirA catalysis. We characterized the developed CMSP and used it to establish a MrgprX2-Avi-tag/CMC-HPLC/MS two-dimensional screening platform, successfully screening vitexicarpin fromViticis Fructus extract via a 2D/CMC platform. In vitro and in vivo experiments confirmed that vitexicarpin targets the MrgprX2 receptor, demonstrating antiallergic effects. Our IB-Avi tag-based CMC approach effectively decreased nonspecific adsorption of the screening materials. The Avi-tag-based 2D/CMC platform is suitable for screening potential drug candidates.

The Effect of Acupuncture on Brain Iron Deposition and Body Iron Metabolism in Vascular Cognitive Impairment: Protocol for a Randomized Controlled Trial.

BACKGROUND: Vascular cognitive impairment (VCI) persistently impairs cognition and the ability to perform activities of daily living, seriously compromising patients' quality of life. Previous studies have reported that disorders of serum iron metabolism and iron deposition in the brain can lead to inflammation, abnormal protein aggregation and degeneration, and massive neuronal apoptosis in the central nervous system, which in turn leads to a progressive decline in cognitive processes. Our previous clinical studies have found acupuncture to be a safe and effective intervention for treating VCI, but the specific mechanisms require further exploration. OBJECTIVE: The objective of the trial is to evaluate the clinical efficacy of Tongdu Xingshen acupuncture and to investigate whether it can improve VCI by regulating brain iron deposition and body iron metabolism. METHODS: In total, 42 patients with VCI and 21 healthy individuals will participate in this clinical trial. The 42 patients with VCI will be randomized into acupuncture and control groups, while the 21 healthy individuals will be in the healthy control group. Both the control and acupuncture groups will receive conventional medical treatment and cognitive rehabilitation training. In addition, the acupuncture group will receive electroacupuncture treatment with Tongdu Xingshen for 30 minutes each time, 6 times a week for 4 weeks. Meanwhile, the healthy control group will not receive any intervention. All 3 groups will undergo baseline assessments of brain iron deposition, serum iron metabolism, and neuropsychological tests after enrollment. The acupuncture and control groups will be evaluated again at the end of 4 weeks of treatment, as described earlier. By comparing neuropsychological test scores between groups, we will examine the efficacy of Tongdu Xingshen acupuncture in treating VCI. Additionally, we will test the correlations between neuropsychological test scores, brain iron deposition, and body iron metabolism indexes to explore the possible mechanisms of Tongdu Xingshen acupuncture in treating VCI. RESULTS: Participants are currently being recruited. The first participant was enrolled in June 2023, which marked the official start of the experiment. As of the submission of the paper, there were 23 participants. The recruitment process is expected to continue until June 2025, at which point the processing and analysis of data will begin. As of May 15, 2024, up to 30 people have been enrolled in this clinical trial. CONCLUSIONS: This study will provide data on the effects of Tongdu Xingshen acupuncture on cerebral iron deposition as well as somatic iron metabolism in patients with VCI. These results will help to prove whether Tongdu Xingshen acupuncture can improve VCI by regulating brain iron deposition and body iron metabolism, which will provide the clinical and theoretical basis for the wide application of acupuncture therapy in VCI rehabilitation. TRIAL REGISTRATION: China Clinical Registration Agency ChiCTR2300072188; https://tinyurl.com/5fcydtkv. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/56484.

Venetoclax Clinical Pharmacokinetics After Administration of Crushed, Ground or Whole Tablets.

PURPOSE: Venetoclax is a potent, orally bioavailable BCL-2 inhibitor used in the treatment of some hematological malignancies. Crushing tablets may be necessary to help with the administration of venetoclax to patients with swallowing difficulties or patients requiring nasogastric tube feeding. The study was conducted to assess the bioavailability of crushed and finely ground venetoclax tablets relative to whole tablets. METHODS: An open-label, randomized, 3-way, crossover study in 15 healthy adult females was conducted. Venetoclax tablets were administered orally in a crushed, ground or intact form on Day 1 of each period with water following a high-fat breakfast. Pharmacokinetic samples were collected up to 72 hours postdosing. FINDINGS: The crushed and ground tablets met the bioequivalence criteria (0.80-1.25) relative to the intact tablets with respect to area under the concentration-time curve to time of the last measurable concentration (AUCt) and to infinite time (AUCinf) but exhibited a slightly lower maximum plasma concentration (Cmax). This was not considered clinically significant as only venetoclax overall exposure (AUC) has been shown to correlate with clinical efficacy. There was no change in the physical appearance and the evaluated physicochemical properties of crushed and ground venetoclax tablets after 72 hours of storage at 25°C/60% relative humidity. IMPLICATIONS: Crushing or grinding venetoclax tablets before administration could be considered as a viable alternative method of administration for patients who have difficulty swallowing whole venetoclax tablets or patients requiring nasogastric tube feeding. GOV IDENTIFIERS: NCT05909553, registered June 12, 2023.

Degradation and fermentation of hyaluronic acid by Bacteroides spp. from the human gut microbiota.

Bacteroides spp. are prominent members of the human gut microbiota that play critical roles in the metabolism of complex carbohydrates from the daily diet. Hyaluronic acid (HA) is a multifunctional polysaccharide which has been extensively used in the food and biomedical industry. However, how HA is degraded and fermented by Bacteroides spp. has not been fully characterized. Here, we comprehensively investigated the detailed degradation profiles and fermentation characteristics of four different HAs with discrete molecular weight (Mw) by fourteen distinctive Bacteroides spp. from the human gut microbiota. Our results indicated that high-Mw HAs were more degradable and fermentable than low-Mw HAs. Interestingly, B. salyersiae showed the best degrading capability for both high-Mw and low-Mw HAs, making it a keystone species for HA degradation among Bacteroides spp.. Specifically, HA degradation by B. salyersiae produced significant amounts of unsaturated tetrasaccharide (udp4). Co-culture experiments indicated that the produced udp4 could be further fermented and utilized by non-proficient HA-degraders, suggesting a possible cross-feeding interaction in the utilization of HA within the Bacteroides spp.. Altogether, our study provides novel insights into the metabolism of HA by the human gut microbiota, which has considerable implications for the development of new HA-based nutraceuticals and medicines.

Bacteroides salyersiae is a potent chondroitin sulfate-degrading species in the human gut microbiota.

Chondroitin sulfate (CS) has widely been used as a symptomatic slow-acting drug or a dietary supplement for the treatment and prevention of osteoarthritis. However, CS could not be absorbed after oral intake due to its polyanionic nature and large molecular weight. Gut microbiota has recently been proposed to play a pivotal role in the metabolism of drugs and nutrients. Nonetheless, how CS is degraded by the human gut microbiota has not been fully characterized. In the present study, we demonstrated that each human gut microbiota was characterized with a unique capability for CS degradation. Degradation and fermentation of CS by the human gut microbiota produced significant amounts of unsaturated CS oligosaccharides (CSOSs) and short-chain fatty acids. To uncover which microbes were responsible for CS degradation, we isolated a total of 586 bacterial strains with a potential CS-degrading capability from 23 human fecal samples. Bacteroides salyersiae was a potent species for CS degradation in the human gut microbiota and produced the highest amount of CSOSs as compared to other well-recognized CS-degraders, including Bacteroides finegoldii, Bacteroides thetaiotaomicron, Bacteroides xylanisolvens, and Bacteroides ovatus. Genomic analysis suggested that B. salyersiae was armed with multiple carbohydrate-active enzymes that could potentially degrade CS into CSOSs. By using a spent medium assay, we further demonstrated that the unsaturated tetrasaccharide (udp4) produced by the primary degrader B. salyersiae could serve as a "public goods" molecule for the growth of Bacteroides stercoris, a secondary CS-degrader that was proficient at fermenting CSOSs but not CS. Taken together, our study provides insights into the metabolism of CS by the human gut microbiota, which has promising implications for the development of medical and nutritional therapies for osteoarthritis. Video Abstract.

Polyguluronate alleviates ulcerative colitis by targeting the gut commensal Lactobacillus murinus and its anti-inflammatory metabolites.

Polyguluronate (PG) is a fermentable polysaccharide from edible algae. The present study was designed to investigate the therapeutic effect of PG on ulcerative colitis (UC) and its underlying mechanisms. Our results suggest that oral intake of PG attenuates UC and improves gut microbiota dysbiosis by promoting the growth of Lactobacillus spp. in dextran sulfate sodium-fed mice. Five different species of Lactobacillus were isolated from the feces of PG-treated mice and L. murinus was identified to have the best anti-colitis effect, suggesting a critical role for L. murinus in mediating the therapeutic effect of PG. Furthermore, PG was degraded potentially by the beta-glucuronidase from L. murinus and adding PG to the culture medium of L. murinus remarkably increased its production of anti-inflammatory metabolites, including itaconic acid, cis-11,14-eicosadienoic acid, and 3-amino-3-(2-chlorophenyl)-propionic acid. Additionally, L. salivarius, a human intestine-derived PG-utilizing species that is closely related to L. murinus, was also demonstrated to have potent anti-colitis effects, suggesting that it is a candidate target of PG in the human gut. Altogether, our study illustrates an unprecedented application of PG in the treatment of UC and establishes the basis for understanding its therapeutic effect from the perspective of L. murinus and its metabolites.

The Chinese Zodiac-in-Noise Test: An Internet-Based Speech-in-Noise Test for Large-Scale Hearing Screening.

OBJECTIVES: Motivated by the growing need for hearing screening in China, the present study has two objectives. First, to develop and validate a new test, called the Chinese Zodiac-in-noise (ZIN) test, for large-scale hearing screening in China. Second, to conduct a large-scale remote hearing screening in China, using the ZIN test developed. DESIGN: The ZIN test was developed following a similar procedure as the digits-in-noise test but emphasizes the importance of consonant recognition by employing the 12 zodiac animals in traditional Chinese culture as speech materials. It measures the speech reception threshold (SRT) using triplets of Chinese zodiac animals in speech-shaped noise with an adaptive procedure. RESULTS: Normative data of the test were obtained in a group of 140 normal-hearing listeners, and the performance of the test was validated by comparisons with pure-tone audiometry in 116 listeners with various hearing abilities. The ZIN test has a reference SRT of -11.0 ± 1.6 dB in normal-hearing listeners with a test-retest variability of 1.7 dB and can be completed in 3 minutes. The ZIN SRT is highly correlated with the better-ear pure-tone threshold ( r = 0.82). With a cutoff value of -7.7 dB, the ZIN test has a sensitivity of 0.85 and a specificity of 0.94 for detecting a hearing loss of 25 dB HL or more at the better ear.A large-scale remote hearing screening involving 30,552 participants was performed using the ZIN test. The large-scale study found a hearing loss proportion of 21.0% across the study sample, with a high proportion of 57.1% in the elderly study sample aged over 60 years. Age and gender were also observed to have associations with hearing loss, with older individuals and males being more likely to have hearing loss. CONCLUSIONS: The Chinese ZIN test is a valid and efficient solution for large-scale hearing screening in China. Its remote applications may improve access to hearing screening and enhance public awareness of hearing health.

Potential of a Miniature Spectral Analyzer for District-Scale Monitoring of Multiple Gaseous Air Pollutants.

Gas sensors that can measure multiple pollutants simultaneously are highly desirable for on-site air pollution monitoring at various scales, both indoor and outdoor. Herein, we introduce a low-cost multi-parameter gas analyzer capable of monitoring multiple gaseous pollutants simultaneously, thus allowing for true analytical measurement. It is a spectral sensor consisting of a Fourier-transform infrared (FTIR) gas analyzer based on a mid-infrared (MIR) spectrometer. The sensor is as small as 7 × 5 × 2.5 cm3. It was deployed in an open-path configuration within a district-scale climatic chamber (Sense City, Marne-la-Vallée, France) with a volume of 20 × 20 × 8 m3. The setup included a transmitter and a receiver separated by 38 m to enable representative measurements of the entire district domain. We used a car inside the climatic chamber, turning the engine on and off to create time sequences of a pollution source. The results showed that carbon dioxide (CO2) and water vapor (H2O) were accurately monitored using the spectral sensor, with agreement with the reference analyzers used to record the pollution levels near the car exhaust. Furthermore, the lower detection limits of CO, NO2 and NO were assessed, demonstrating the capability of the sensor to detect these pollutants. Additionally, a preliminary evaluation of the potential of the spectral sensor to screen multiple volatile organic compounds (VOCs) was conducted at the laboratory scale. Overall, the results demonstrated the potential of the proposed multi-parameter spectral gas sensor in on-site gaseous pollution monitoring.

Impact of Influenza and Pneumococcal Polysaccharide Vaccination on Economic Burden from Acute Exacerbations of Chronic Obstructive Pulmonary Disease - Hebei Province, China, November 2018 to November 2020.

What is already known on this topic?: Chronic obstructive pulmonary disease (COPD) exacerbations increase household economic burden, but there is limited evidence from prospective cohort studies in China about the impact of vaccination on economic burden. What is added by this report?: This study demonstrated the economic burden of COPD exacerbations, pneumonia, and hospitalization in COPD patients in China is substantial. Influenza vaccine and 23-valent pneumococcal polysaccharide vaccine (PPSV23), separately or together, were significantly associated with decreased economic burden. What are the implications for public health practice?: Our study supports evidence on recommendations that COPD patients in China are offered both influenza vaccine and PPSV23.

Survey on Immunization Services for Children with Medical Conditions - China, 2022.

What is already known about this topic?: Children with medical conditions frequently experience under-immunization. Ensuring high-quality immunization services is crucial for enhancing vaccination coverage levels; nevertheless, the state of immunization service provision for children with medical conditions in China remains unclear. What is added by this report?: Immunization support for children with medical conditions in China demonstrates considerable variability and may be inadequate. Primary obstacles to the provision of immunization services include an absence of comprehensive vaccination recommendations and assessment guidelines for specific medical conditions, as well as inconsistencies among vaccine recommendations, package inserts, and expert consensus statements pertaining to the vaccination of children with medical conditions. What are the implications for public health practice?: The examination of provincial practices in providing immunization services for children with medical conditions, as well as understanding the barriers faced by National Immunization Program providers in administering vaccinations, can contribute to the improvement of immunization services for this population in China.

Effect of type of ion and temperature on fines migration induced by mineral reactions during water injection into carbonate rocks.

Managed aquifer recharge is a water storage and recovery method. However, fines migration during water injection can significantly affect formation permeability. Several studies have analyzed fines migration in sandstone and soil samples, but few studies have investigated fines migration in carbonate rocks. In addition, the effect of neither temperature nor type of ion on fines migration has been investigated in carbonate rocks. Our experiments use filtered-deaired distilled water and pure salts to prepare the injection fluids. Rock samples are injected with 0.63 mol/L brine followed by four sequential injections of diluted brine: 0.21 mol/L, 0.1 mol/L, 0.05 mol/L, and 0 mol/L (distilled water). Pressure difference is recorded across the rock sample throughout each experimental run and used to calculate permeability. Effluent is collected to characterize produced fines and elements. pH and particle concentration measurements are collected frequently. Scanning electron microscope (SEM) images of inlet and outlet faces pre- and post-injection were taken to observe any changes. For the experimental runs performed at 25 °C, permeability decrease was 99.92% of the original permeability for seawater experimental run, 99.96% for NaCl brine experimental run, and nearly zero for CaCl2 brine experimental run. For CaCl2 brine experimental run, the only observed mineral reaction is mineral dissolution. For NaCl brine and seawater experimental runs, both mineral dissolution and cation exchange are observed, of which the latter appears to be the main mechanism for fines migration. Due to mineral dissolution, permeability increase is observed during 0.21 mol/L and 0.1 mol/L injection at high temperature. However, during distilled water injection, permeability decrease is found to be similar at both low and high temperatures.

Differentially Private Average Consensus for Networks With Positive Agents.

This research paper addresses the problem of achieving differentially private average consensus for multiagent systems (MASs) consisting of positive agents. A novel randomized mechanism is introduced that employs nondecaying positive multiplicative truncated Gaussian noises to maintain the positivity and randomness of the state information over time. A time-varying controller is developed to achieve mean-square positive average consensus, and convergence accuracy is evaluated. The proposed mechanism is shown to preserve (ϵ,δ) -differential privacy of MASs, and the privacy budget is derived. Numerical examples are provided to illustrate the effectiveness of the proposed controller and privacy mechanism.

The influence of metacognition monitoring on L2 Chinese audiovisual reading comprehension.

Metacognition monitoring is the ability to evaluate the cognitive process actively. L2 learners with high metacognition monitoring ability can better monitor reading processes and outcomes consciously, thus facilitating self-regulated learning and improving reading efficiency. Previous studies mostly used offline self-reports to examine the metacognition monitoring in static text reading by L2 learners. This study investigated the effects of different indicators of metacognition monitoring on L2 Chinese audiovisual comprehension by online confidence judgment and audiovisual comprehension tasks. Target measures of metacognition monitoring included absolute calibration accuracy based on video or test and relative calibration accuracy measured by Gamma or Spearman correlation coefficient. 38 intermediate-advanced Chinese learners participated in the study. Multiple regression analysis showed three main results. First, absolute calibration accuracy can significantly predict L2 Chinese audiovisual comprehension, while relative calibration accuracy has no significant effect. Second, the predictive effect of video-based absolute calibration accuracy is affected by the video difficulty, that is, the greater the video difficulty, the greater the impact on the performance of audiovisual comprehension. Third, the predictive effect of test-based absolute calibration accuracy is influenced by the language proficiency, specifically, the higher the L2 Chinese proficiency, the stronger the prediction on the performance of audiovisual comprehension. These results support a multidimensional view of metacognition monitoring by specifying how different indicators of metacognition monitoring may predict L2 Chinese audiovisual comprehension. The findings have important pedagogical implications for strategy training of metacognition monitoring and point to the necessity to take task difficulty and individual differences among learners into full consideration.

Isolation of Alginate-Degrading Bacteria from the Human Gut Microbiota and Discovery of Bacteroides xylanisolvens AY11-1 as a Novel Anti-Colitis Probiotic Bacterium.

Alginate has been documented to prevent the development and progression of ulcerative colitis by modulating the gut microbiota. However, the bacterium that may mediate the anti-colitis effect of alginate has not been fully characterized. We hypothesized that alginate-degrading bacteria might play a role here since these bacteria could utilize alginate as a carbon source. To test this hypothesis, we isolated 296 strains of alginate-degrading bacteria from the human gut. Bacteroides xylanisolvens AY11-1 was observed to have the best capability for alginate degradation. The degradation and fermentation of alginate by B. xylanisolvens AY11-1 produced significant amounts of oligosaccharides and short-chain fatty acids. Further studies indicated that B. xylanisolvens AY11-1 could alleviate body weight loss and contraction of colon length, reduce the incidences of bleeding and attenuate mucosal damage in dextran sulfate sodium (DSS)-fed mice. Mechanistically, B. xylanisolvens AY11-1 improved gut dysbiosis and promoted the growth of probiotic bacteria, including Blautia spp. And Prevotellaceae UCG-001, in diseased mice. Additionally, B. xylanisolvens AY11-1 showed no oral toxicity and was well-tolerated in male and female mice. Altogether, we illustrate for the first time an anti-colitis effect of the alginate-degrading bacterium B. xylanisolvens AY11-1. Our study paves the way for the development of B. xylanisolvens AY11-1 as a next-generation probiotic bacterium.

Electrochemical Oxidative Cleavage of Alkynes to Carboxylic Acids.

A sustainable method for converting terminal alkynes into their corresponding carboxylic acids is reported using synthetic electrolysis in an undivided cell at room temperature. This protocol, avoiding transition metal catalysis and stoichiometric chemical oxidants, tolerates a variety of aryl, heteroaryl, and alkyl akynes. Preliminary mechanistic studies demonstrate that sodium nitrite serves a triple role as the electrolyte, nitryl radical precursor, and a nitrosating reagent.

Construction and application of covalently bonded CD147 cell membrane chromatography model based on polystyrene microspheres.

In this study, a novel cell membrane chromatography (CMC) model was developed to investigate cluster of differentiation 147 (CD147) targeted anti-tumor drug leads for specific screening and ligand-receptor interaction analysis by SNAP-tagged CD147 fusion protein conjugation and polystyrene microspheres (PS) modification. Traditional Chinese medicines (TCMs) are widely used in the treatment of cancer. CD147 plays important roles in tumor progression and acts as an attractive target for therapeutic intervention; therapeutic drugs for CD147-related cancers are limited to date. Thus, a screening method for active components in TCMs is crucial for the further research and development of CD147 antagonists. However, improvement is still needed to perform specific and accurate drug lead screening using the CMC-based method. Recently, our group developed a covalently immobilized receptor-SNAP-tag/CMC model using silica gel as carrier. Besides the carboxyl group on multi-step modified silica particles, the amino group of benzyl-guanine (BG, substrate of SNAP-tag) also possesses reactivity towards the carboxyl group on available carboxyl-modified PS. Herein, we used PS as carrier and an extended SNAP-tag with CD147 receptor to construct the PS-BG-CD147/CMC model for active compound investigation coupled with HPLC/MS and applied this coupled PS-BG-CD147/CMC-HPLC/MS two-dimensional system to drug lead screening from Nelumbinis Plumula extract (NPE) sample. In addition, to comprehensively verify the pharmacological effects of screened ingredients, a cell proliferation inhibition assay was performed, and the interaction between the ingredients and CD147 was studied by the frontal analysis method. This study developed a high-throughput PS-based CMC screening platform, which could be widely applied and utilized in chromatographic separation and drug lead discovery.