Tandem amplification of a plasmid-borne tet(A) variant gene confers tigecycline resistance in Escherichia coli.

OBJECTIVES: To elucidate the mechanism of tigecycline resistance in Escherichia coli that is mediated by the tet(A) variant gene. METHODS: E. coli strain 573 carried a plasmid-borne tet(A) variant gene, tentatively designated tet(A)TIG, that conferred decreased tigecycline susceptibility (MIC 0.5 mg/L). When exposed to increasing concentrations of tigecycline (0.25-8 mg/L), mutants growing at 2, 4 and 8 mg/L were obtained and sequenced. Copies of plasmid and tet(A)TIG relative to the chromosomal DNA in the mutants were determined by WGS and quantitative PCR (qPCR). Expression of tet(A)TIG in the mutants was evaluated by RT-qPCR. The tet(A)TIG-carrying plasmids were visualized by S1-PFGE and Southern blot hybridization. PCR served for the detection of a tet(A)TIG-carrying unconventional circularizable structure (UCS). RESULTS: Tigecycline resistance with maximum MICs of 16 mg/L was seen in E. coli mutants selected in the presence of tigecycline. Compared with the parental strain, the relative copy number and transcription level of tet(A)TIG in the mutants increased significantly in the presence of 2, 4 and 8 mg/L tigecycline, respectively. With increasing tigecycline selection pressure, the tet(A)TIG-carrying plasmids in the mutants increased in size, correlating with the number of tandem amplificates of a ΔTnAs1-flanked UCS harbouring tet(A)TIG. These tandem amplificates were not stable in the absence of tigecycline. CONCLUSIONS: Tigecycline resistance is due to the tandem amplification of a ΔTnAs1-flanked tet(A)TIG-carrying plasmid-borne segment in E. coli. The gain/loss of the tandem amplificates in the presence/absence of tigecycline represents an economic way for the bacteria to survive in the presence of tigecycline.

Associations of apolipoprotein E ε4 allele, regional cerebral blood flow, and serum liver function markers in patients with cognitive impairment.

Introduction: The ε4 allele of the apolipoprotein E gene (APOE4) is expressed abundantly in both the brain and peripheral circulation as a genetic risk factor for Alzheimer's disease (AD). Cerebral blood flow (CBF) dysfunction is an essential feature of AD, and the liver plays an important role in the pathogenesis of dementia. However, the associations of APOE4 with CBF and liver function markers in patients with cognitive impairment remains unclear. We aimed to evaluate the associations of APOE4 with CBF measured by arterial spin labeling (ASL) magnetic resonance imaging (MRI) and serum liver function markers in participants who were diagnosed with cognitive impairment. Methods: Fourteen participants with AD and sixteen with amnestic mild cognitive impairment (MCI) were recruited. In addition to providing comprehensive clinical information, all patients underwent laboratory tests and MRI. All participants were divided into carriers and noncarriers of the ε4 allele, and T-tests and Mann-Whitney U tests were used to observe the differences between APOE4 carriers and noncarriers in CBF and liver function markers. Results: Regarding regional cerebral blood flow (rCBF), APOE4 carriers showed hyperperfusion in the bilateral occipital cortex, bilateral thalamus, and left precuneus and hypoperfusion in the right lateral temporal cortex when compared with noncarriers. Regarding serum liver function markers, bilirubin levels (including total, direct, and indirect) were lower in APOE4 carriers than in noncarriers. Conclusion: APOE4 exerts a strong effect on CBF dysfunction by inheritance, representing a risk factor for AD. APOE4 may be related to bilirubin metabolism, potentially providing specific neural targets for the diagnosis and treatment of AD.

Thin-Film Composite Membrane Compaction: Exploring the Interplay among Support Compressive Modulus, Structural Characteristics, and Overall Transport Efficiency.

Water scarcity has driven the demand for water production from unconventional sources and the reuse of industrial wastewater. Pressure-driven membranes, notably thin-film composite (TFC) membranes, stand as energy-efficient alternatives to the water scarcity challenge and various wastewater treatments. While pressure drives solvent movement, it concurrently triggers membrane compaction and flux deterioration. This necessitates a profound comprehension of the intricate interplay among compressive modulus, structural properties, and transport efficacy amid the compaction process. In this study, we present an all-encompassing compaction model for TFC membranes, applying authentic structural and mechanical variables, achieved by coupling viscoelasticity with Monte Carlo flux calculations based on the resistance-in-series model. Through validation against experimental data for multiple commercial membranes, we evaluated the influence of diverse physical parameters. We find that support polymers with a higher compressive modulus (lower compliance), supports with higher densities of "finger-like" pores, and "sponge-like" pores with optimum void fractions will be preferred to mitigate compaction. More importantly, we uncover a trade-off correlation between steady-state permeability and the modulus for identical support polymers displaying varying porosities. This model holds the potential as a valuable guide in shaping the design and optimization for further TFC applications and extending its utility to biological scaffolds and hydrogels with thin-film coatings in tissue engineering.

Effect of Social Support on Career Decision-Making Difficulties: The Chain Mediating Roles of Psychological Capital and Career Decision-Making Self-Efficacy.

This present study explores the effect of social support on career decision-making difficulties, with the chain mediation of psychological capital and career decision-making self-efficacy. A total of 770 college students were recruited to complete the survey, which included a social support, career decision-making self-efficacy, psychological capital scale, and career decision-making difficulties scales. Significant correlations were found between social support, career decision-making difficulties, psychological capital, and career decision making self-efficacy. Path analysis indicated that the direct effect of social support on career decision-making difficulty was non-significant; social support affected career decision-making difficulties indirectly through not only the mediating effect of psychological capital but also through the chain mediation of psychological capital and career decision-making self-efficacy. Overall, the results show that social support could exert an effect on career decision-making difficulties through the mediational chains of career decision-making self-efficacy and psychological capital; the implications of this are discussed.

Associations of Serum Liver Function with Cerebral Blood Flow in Patients with Alzheimer's Disease.

Background: Increasing evidence suggests that both amyloid-ß metabolism disorders in the liver and cerebral hypoperfusion play an important role in the pathogenesis of Alzheimer's disease (AD). However, the relevance of liver function alterations to cerebral blood flow (CBF) of patients with AD remains unclear. Objective: We aimed to investigate the associations between liver function changes and CBF of patients with AD. Methods: We recruited 17 patients with sporadic AD. In addition to physical and neurological examinations, detection of AD biomarkers in cerebrospinal fluid by enzyme-linked immunosorbent assay and CBF assessment by arterial spin labeling sequence of magnetic resonance image scans as well as measure of liver function markers in serum by routine laboratory testing were conducted. Neuropsychological tests were evaluated, including Mini-Mental State Examination and Montreal Cognitive Assessment. Linear and rank correlations were performed to test the associations of liver function alterations with regional CBF of AD. Results: We found that liver function markers, especially total protein, the ratio of albumin to globin, globin, alkaline phosphatase, and aspartate aminotransferase were significantly associated with regional CBF of AD patients. Conclusions: These findings demonstrated significant associations between perfusion in certain brain regions of AD and alterations of liver function markers, particularly proteins and liver enzymes, which might provide implications to the pathogenesis and treatment of AD.

Effects of tumor necrosis factor-alpha inhibitors on lipid profiles in patients with psoriasis: a systematic review and meta-analysis.

Background: There is no consensus on the effect of tumor necrosis factor-alpha (TNF-alpha) inhibitors on lipid profiles in patients with psoriasis. This study aimed to investigate the effects of TNF-alpha inhibitors on lipid profiles (triglycerides, total cholesterol, low-density lipoprotein, or high-density lipoprotein) in patients with psoriasis. Methods: We searched PubMed, Embase, and Cochrane Library databases for articles published before October 17, 2023. Four TNF-alpha inhibitors (infliximab, etanercept, adalimumab, and certolizumab) were included in our study. (PROSPERO ID: CRD42023469703). Results: A total of twenty trials were included. Overall results revealed that TNF-alpha inhibitors elevated high-density lipoprotein levels in patients with psoriasis (WMD = 2.31; 95% CI: 0.96, 3.67; P = 0.001), which was supported by the results of sensitivity analyses excluding the effect of lipid-lowering drugs. Subgroup analyses indicated that high-density lipoprotein levels were significantly increased in the less than or equal to 3 months group (WMD = 2.88; 95% CI: 1.37, 4.4; P < 0.001), the etanercept group (WMD = 3.4; 95% CI = 1.71, 5.09, P < 0.001), and the psoriasis group (WMD = 2.52; 95% CI = 0.57, 4.48, P = 0.011). Triglyceride levels were significantly increased in the 3 to 6-month group (WMD = 4.98; 95% CI = 1.97, 7.99, P = 0.001) and significantly decreased in the 6-month and older group (WMD = -19.84; 95% CI = -23.97, -15.7, P < 0.001). Additionally, Triglyceride levels were significantly increased in the psoriasis group (WMD = 5.22; 95% CI = 2.23, 8.21, P = 0.001). Conclusion: Our results revealed that TNF-alpha inhibitors might temporarily increase high-density lipoprotein levels in patients with psoriasis. However, changes in triglycerides were not consistent among the different durations of treatment, with significant increases after 3 to 6 months of treatment. Future prospective trials with long-term follow-up contribute to confirming and extending our findings. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023469703.

Electrolyte Optimization Strategy: Enabling Stable and Eco-Friendly Zinc Adaptive Interfacial Layer in Zinc Ion Batteries.

Aqueous zinc ion batteries (AZIBs) have emerged as a promising battery technology due to their excellent safety, high capacity, low cost, and eco-friendliness. However, the cycle life of AZIBs is limited by severe side reactions and zinc dendrite growth on the zinc electrode surface, hindering large-scale application. Here, an electrolyte optimization strategy utilizing the simplest dipeptide glycylglycine (Gly-Gly) additive is first proposed. Theoretical calculations and spectral analysis revealed that, due to the strong interaction between the amino group and Zn atoms, Gly-Gly preferentially adsorbs on zinc's surface, constructing a stable and adaptive interfacial layer that inhibits zinc side reactions and dendrite growth. Furthermore, Gly-Gly can regulate zinc ion solvation, leading to a deposition mode shift from dendritic to lamellar and limiting two-dimensional dendrite diffusion. The symmetric cell with the addition of a 20 g/L Gly-Gly additive exhibits a cycle life of up to 1100 h. Under a high current density of 10 mA cm-2, a cycle life of 750 cycles further demonstrates the reliable adaptability of the interfacial layer. This work highlights the potential of Gly-Gly as a promising solution for improving the performance of AZIBs.

Molecular detection and genetic characteristics of Giardia duodenalis in dairy cattle from large-scale breeding farms in Xinjiang, China.

Giardia duodenalis is an intestinal protozoan that can infect both humans and animals, leading to public health issues and economic losses in the livestock industry. G. duodenalis has been reported to infect dairy cattle, but there is limited information available on large-scale dairy farms in Xinjiang, China. The study collected 749 fresh faecal samples from five large-scale cattle farms in Xinjiang, China. The study used a nested PCR assay of the small subunit ribosomal RNA (SSU rRNA*) gene to determine the presence of G. duodenalis. The results showed that 24.0% (180/749) of dairy cattle were positive for G. duodenalis, with the highest infection rate observed in pre-weaned calves (45.1%, 69/153). Among the 180 G. duodenalis positive samples, three assemblages were identified: assemblage E (n = 176), assemblage A (n = 3) and assemblage B (n = 1). Sixty-nine, 67 and 49 sequences were obtained for the beta-giardin (bg*) gene, the glutamate dehydrogenase (gdh*) gene and the triose phosphate isomerase (tpi*) gene, respectively. Thirteen novel sequences of assemblage E were identified, including five sequences from the bg* gene, four sequences from the gdh* gene and four sequences from the tpi* gene. This study found that 32 G. duodenalis assemblage E isolates formed 26 MLGs, indicating genetic variation and geographic isolation-based differentiation in bovine-derived G. duodenalis assemblage E. These findings provide fundamental insights into the genetic diversity of G. duodenalis in dairy cattle and can aid in the prevention and control of its occurrence in large-scale dairy cattle farms.

Colquhounia root tablet in the treatment of idiopathic membranous nephropathy with subnephrotic proteinuria.

PURPOSE: Idiopathic membranous nephropathy (IMN) is the most frequent global cause of nephrotic syndrome in non-diabetic people. In clinical practice, An effective and mild treatment for IMN patients with subnephrotic proteinuria has been adopted. Colquhounia root tablet (CRT) is a traditional Chinese medicine that is widely used in China to treat glomerulopathies. In this study, the effectiveness and safety of CRT in the treatment of IMN with subnephrotic proteinuria have been determined by reviewing the clinical records of 44 patients with IMN. METHODS: Retrospective analysis of IMN patients with subnephrotic proteinuria treated with CRT in combination with ACEI/ARB or ACEI/ARB alone. The remission rate (complete or partial remission) was the main outcome observed, and proteinuria, estimated glomerular filtration rate (eGFR), serum albumin levels, and adverse effects were the secondary outcomes. RESULTS: This clinical trial included 44 patients, and the overall remission rates at months 6, 9, and 12 after treatment were 68.2% versus 27.3% (p = 0.016), 72.7% versus 36.4% (p = 0.015), and 77.3% versus 36.4% (p = 0.006) in the treatment and control groups, respectively. The application of CRT treatment was an independent predictor of proteinuria remission (p = 0.024). In addition, in patients who were positive for phospholipase A2 receptor (PLA2R) antibodies, the overall remission rate was higher in the treatment group than in the control group after 9 months of treatment (75% versus 23.08%, p = 0.017). CONCLUSION: This retrospective study illustrates that, based on supportive therapy, CRT could be effective in the treatment of IMN with subnephrotic proteinuria with a good safety profile at the same time.

Nomograms for the prediction of decannulation in patients with neurological injury: a study based on clinical practice.

BACKGROUND: Rational prediction of the probability of decannulation in tracheotomy patients is of great importance to clinicians and patients' families. This study aimed to develop a prediction model for decannulation in tracheotomized patients with neurological injury using routine clinical data and blood tests. METHODS: We developed a prediction model based on 186 tracheotomized patients, and data were collected from January 2018 to March 2021. The least absolute shrinkage and selection operator (LASSO) regression model was used to optimize feature selection for the decannulation risk model. The performance of the prediction model was evaluated in terms of discrimination, calibration, and clinical utility using measures such as C-index, calibration plot, and decision curve analysis (DCA). Internal validation was performed through bootstrapping validation. RESULTS: A total of 66.13% (123/186) of patients were decannulated. Predictors included in the prediction nomogram were age, gender, subtype of neurological injury, Glasgow Coma Scale (GCS) score, swallowing function, duration of tracheotomy, procalcitonin (PCT) level, white blood cell (WBC) count, and serum albumin (ALB) level. The predictive model showed good discrimination, with a C-index of 0.755 (95% confidence interval: 0.68-0.83). Internal validation also confirmed a satisfactory C-index of 0.690. The DCA indicated that the nomogram added substantial value in predicting decannulation risk for patients with threshold probabilities falling between >21% and <98% compared to the existing scheme. CONCLUSIONS: This predictive model serves as a valuable instrument for clinicians to quantitatively assess the probability of decannulation in patients with neurological injury, aiding in informed decision-making and patient management.

Ectoine Globally Hypomethylates DNA in Skin Cells and Suppresses Cancer Proliferation.

Epigenetic modifications, mainly aberrant DNA methylation, have been shown to silence the expression of genes involved in epigenetic diseases, including cancer suppression genes. Almost all conventional cancer therapeutic agents, such as the DNA hypomethylation drug 5-aza-2-deoxycytidine, have insurmountable side effects. To investigate the role of the well-known DNA protectant (ectoine) in skin cell DNA methylation and cancer cell proliferation, comprehensive methylome sequence analysis, 5-methyl cytosine (5mC) analysis, proliferation and tumorigenicity assays, and DNA epigenetic modifications-related gene analysis were performed. The results showed that extended ectoine treatment globally hypomethylated DNA in skin cells, especially in the CpG island (CGIs) element, and 5mC percentage was significantly reduced. Moreover, ectoine mildly inhibited skin cell proliferation and did not induce tumorigenicity in HaCaT cells injected into athymic nude mice. HaCaT cells treated with ectoine for 24 weeks modulated the mRNA expression levels of Dnmt1, Dnmt3a, Dnmt3b, Dnmt3l, Hdac1, Hdac2, Kdm3a, Mettl3, Mettl14, Snrpn, and Mest. Overall, ectoine mildly demethylates DNA in skin cells, modulates the expression of epigenetic modification-related genes, and reduces cell proliferation. This evidence suggests that ectoine is a potential anti-aging agent that prevents DNA hypermethylation and subsequently activates cancer-suppressing genes.

Establishment of a model for predicting preterm birth based on the machine learning algorithm.

BACKGROUND: The purpose of this study was to construct a preterm birth prediction model based on electronic health records and to provide a reference for preterm birth prediction in the future. METHODS: This was a cross-sectional design. The risk factors for the outcomes of preterm birth were assessed by multifactor logistic regression analysis. In this study, a logical regression model, decision tree, Naive Bayes, support vector machine, and AdaBoost are used to construct the prediction model. Accuracy, recall, precision, F1 value, and receiver operating characteristic curve, were used to evaluate the prediction performance of the model, and the clinical application of the model was verified. RESULTS: A total of 5411 participants were included and were used for model construction. AdaBoost model has the best prediction ability among the five models. The accuracy of the model for the prediction of "non-preterm birth" was the highest, reaching 100%, and that of "preterm birth" was 72.73%. CONCLUSIONS: By constructing a preterm birth prediction model based on electronic health records, we believe that machine algorithms have great potential for preterm birth identification. However, more relevant studies are needed before its application in the clinic.

A MXene@AgAu@PDA nanoplatform loaded with AgAu nanocages for enhancing catalytic activity and antibacterial performance.

With the rapid development of social industrialization, environmental problems seriously threaten people's health, especially water pollution. Therefore, there is an urgent need to construct a multifunctional nanoplatform for different scenarios. Two-dimensional MXene@AgAu@PDA nanosheets loaded with AgAu bimetallic nanocages have been prepared by a one-step method. First, the in situ generated MXene@Ag is used as an auxiliary template, and then HAuCl4 and dopamine are added for in situ redox-oxidizing polymerization reactions to obtain AgAu catalytic nanocages and the protective polydopamine (PDA) layer which can improve the stability and biocompatibility. MXene and PDA have excellent photothermal conversion ability while hollow AgAu nanocages have strong absorption in the near-infrared region and a local surface plasmonic resonance effect. In comparison to the catalytic reaction rates under dark and room temperature conditions, the catalytic kinetic rate of MXene@AgAu@PDA nanosheets under near-infrared irradiation increases from 0.13 to 0.69 min-1 mg-1. Density functional theory (DFT) is used to study the electron transfer behavior between AgAu nanocages and MXene nanosheets, and the mechanism of the enhanced catalytic reaction rate is analyzed. Besides, due to its Ag ions and photothermal coupling antibacterial properties, 40 µg mL-1 MXene@AgAu@PDA nanosheets inactivates nearly all E. coli and S. aureus after irradiation with near-infrared light for 6 min.

Occurrence and genetic characteristics of Giardia duodenalis in donkeys in Xinjiang, China.

Giardia duodenalis is a common enteric parasite in humans and animals. To examine the occurrence and genetic characteristics of Giardia in donkeys in Xinjiang, China, 758 fecal samples from donkeys were collected, and Giardia was screened via PCR at the SSU rRNA gene. A total of 17.0% (129/758) of samples tested positive for Giardia, with the infection rate in large-scale farm and domestic donkeys being 21.4% (124/580) and 2.8% (5/178), respectively; the infection rates in <1-year-old and ≥1-year-old donkeys were 19.3% (72/374) and 12.7% (41/323), respectively. Three Giardia assemblages were identified, with assemblage B (n = 102) as the prevalent assemblage, followed by assemblage A (n = 23) and assemblage E (n = 4). Of the 129 Giardia-positive isolates, 40, 34 and 59 sequences were obtained at the bg, gdh and tpi genes, respectively. Twenty-one isolates successfully allowed multilocus genotyping (MLG), with four novel assemblage A MLGs, named MLG-AI-1 (n = 1), MLG-AI-2 (n = 1), MLG-AI-3 (n = 1), and MLG-AI-4 (n = 1) and three novel assemblage B MLGs, named MLG-B1 (n = 1), MLG-B2 (n = 14), and MLG-B3 (n = 1). Moreover, two isolates formed two MLG-mixed sequences. The results suggest that donkeys are commonly infected with Giardia in Xinjiang, and there is genetic diversity and host adaptability among the isolates.

Title: Présence et caractéristiques génétiques de Giardia duodenalis chez les ânes du Xinjiang, Chine. Abstract: Giardia duodenalis est un parasite entérique courant chez les humains et les animaux. Pour étudier la présence et les caractéristiques génétiques de Giardia chez les ânes du Xinjiang, en Chine, 758 échantillons fécaux d'ânes ont été collectés et Giardia a été criblé par PCR du gène de l'ARNr SSU. Au total, 17,0 % (129/758) des échantillons ont été testés positifs pour Giardia. Le taux d'infection, respectivement chez les ânes des élevages à grande échelle et domestiques, étaient de 21,4 % (124/580) et 2,8 % (5/178). Les taux chez les ânes de < 1 an et ≥ 1 an étaient respectivement de 19,3 % (72/374) et 12,7 % (41/323). Trois assemblages de Giardia ont été identifiés, l'assemblage B (n = 102) étant l'assemblage prédominant, suivi de l'assemblage A (n = 23) et de l'assemblage E (n = 4). Sur les 129 isolats positifs pour Giardia, 40, 34 et 59 séquences ont été obtenues respectivement au niveau des gènes bg, gdh et tpi. Vingt et un isolats ont permis du génotypage multilocus (MLG), avec quatre nouveaux MLG de l'assemblage A, nommés MLG-AI-1 (n = 1), MLG-AI-2 (n = 1), MLG-AI-3 (n = 1) et MLG-AI-4 (n = 1) et trois nouveaux MLG de l'assemblage B, nommés MLG-B1 (n = 1), MLG-B2 (n = 14) et MLG-B3 (n = 1). De plus, deux isolats formaient deux séquences MLG mélangés. Les résultats suggèrent que les ânes sont couramment infectés par Giardia au Xinjiang, et qu'il existe une diversité génétique et une adaptabilité à l'hôte parmi les isolats.

Metagenomic investigations on antibiotic resistance and microbial virulence in oil-polluted soils from China.

Engine oil spills have been associated with a wide range of human health problems. However, little is known about the effects of petroleum hydrocarbon pollution on soil microbial communities. In this study, three samples were collected from oil-polluted soils (OPS), and one control soil (CS) from Taolin town, China, near the old engine's scrapes was used. The aims of this study were to conduct metagenomic sequencing and subsequently perform resistome and virulome analysis. We also aimed to validate anti-microbial resistance and virulence genes and anti-bacterial sensitivity profiles among the isolates from oil-polluted soils. The OPS microbial community was dominated by bacterial species compared to the control samples which were dominated by metazoans and other organisms. Secondly, the resistosome and virulome analysis showed that ARGs and virulence factors were higher among OPS microbial communities. Antibiotic susceptibility assay and qPCR analysis for ARGs and virulence factors showed that the oil-polluted soil samples had remarkably enhanced expression of these ARGs and some virulence genes. Our study suggests that oil pollution contributes to shifting microbial communities to more resilient types that could survive the toxicity of oil pollution and subsequently become more resilient in terms of higher resistance and virulence potential.

Liquid Chromatography-Tandem Mass Spectrometry Detection of Human and Veterinary Drugs and Pesticides in Surface Water.

Antibiotics and pesticides are widespread in most rivers and lakes due to the overuse of antibiotics and pesticides, but there are few methods for simultaneous analysis of antibiotics and pesticides in aquatic environments. To address this knowledge gap, a concise and sensitive analytical method is proposed in which three classes of human and veterinary drugs (sulfonamides, macrolides, and hormones) and two classes of pesticides (organophosphorus and neonicotinoids) are simultaneously extracted and determined in surface water. The solid-phase extraction column with Cleanert PEP-2 was preconditioned sequentially with 6 mL of methanol, ultrapure water, and citric acid buffer (pH 3.0) each for simultaneous extraction and further purification. The forty-seven target analytes were analysed by LC-MS/MS in positive and negative ion modes. The LC separation was performed using a Sigma-Aldrich C18 column with 0.1% formic acid in water and acetonitrile as a gradient eluting mobile phase in positive ion mode. The internal standard method was used to overcome the inevitable matrix effects in LC-MS/MS analysis. The matrix effects of most target analytes were in the range of 27-151%. The recoveries of forty analytes in the three concentrations (10, 50, and 100 ng L-1) of surface water spiked samples ranged from 41 to 127%. The method quantitative limits of the analytes were in the range of 0.40-5.49 ng L-1. Application of the method to analyze samples in the eight runoff outlets of the Pearl River Delta showed that some antibiotics and pesticides were detected, and the concentration of parathion was as high as 154 ng L-1. A powerful tool for quickly and efficiently screening for contaminants in surface water has been presented.

Traumatic brain injury and rTMS-ERPs: Case report and literature review.

Currently, there are no cases of targeted, individualized repeated transcranial magnetic stimulation (rTMS) treatment based on event-related potential (ERPs) results showing the activation of functional brain regions. The identification and treatment of mild cognitive impairment after traumatic brain injury are challenging. rTMS has shown unique advantages in previous studies, with positive effects on noninvasive modulation and neuroplasticity after brain injury. The selection of the rTMS parameters and targets remains controversial. ERPs indicate the cortical activity involved in cognitive processing in patients. Therefore, this study proposes that ERPs can be used as biomarkers of cognitive recovery. The results of this study will guide the development of rTMS protocols for patient treatment. To help clinicians better apply rTMS and ERPs in combination, we conducted a relevant literature review and discussion, detailing the therapeutic mechanisms of the combination of ERPs and rTMS. This will facilitate the precise assessment and personalized treatment of such patients, improve the abnormal processing patterns of patients, and promote their return to life and society.

Emergence of high-level tigecycline resistance due to the amplification of a tet(A) gene variant in clinical carbapenem-resistant Klebsiella pneumoniae.

OBJECTIVE: To investigate the prevalence of a tet(A) gene variant and its role in developing high-level tigecycline resistance among carbapenem-resistant Klebsiella pneumoniae (CRKP) clinical isolates. METHODS: The mechanism of high-level tigecycline resistance in CRKP mediated by a tet(A) variant was explored by induction experiments, antimicrobial susceptibility testing, whole-genome sequencing and bioinformatics analysis. The amplification and overexpression of the tet(A) variant were measured by the determination of sequencing depth, gene copy numbers, and qRT-PCR. RESULTS: A high rate (62.1%, 998/1607) of tet(A) variant carriage was observed among 1607 CRKP clinical isolates from Henan Province, China. High-level tigecycline resistance could rapidly develop by the amplification of the tet(A) variant in these isolates. The analysis of the raw sequencing data and the plasmid mapping depth revealed that the ΔtnpA homologous sequence of Tn1721 supports the amplification of the region that harbours the tet(A) variant by forming a large number of repeat arrays through translocatable units (TUs). Moreover, the epidemiological analysis of tet(A) variant-carrying structures among 1607 clinical CRKPs showed that the TU structure is widely present. CONCLUSION: The presence of a tigecycline resistance-mediating tet(A) variant in CRKP clinical isolates represents a greater health concern than initially thought and should be monitored consistently.