Use of the Disposcope endoscope for awake orotracheal intubation in an elderly patient with a large vocal cord polyp -a case report.

BACKGROUND: Vocal cord polyps are commonly encountered in the otorhinolaryngology department. The risk of anesthesia is high in patients with large vocal cord polyps. Awake intubation with appropriate airway tools provides a favorable safety profile. CASE: We present the case of a 60-year-old male patient who had been suffering from a large vocal cord polyp for 16 years. Electronic laryngoscopy revealed that the vocal cord polyp was approximately 1.5 cm in diameter. The polyp had a pedicle and demonstrated synchronous motion with respiratory excursion. It covered almost the entire glottic area during inspiration and moved away from the glottis during expiration. A Disposcope endoscope was used for awake tracheal intubation, and the surgery was completed successfully. CONCLUSIONS: The Disposcope endoscope can be a useful option for awake orotracheal intubation in cases of anticipated difficult intubation and difficult facemask ventilation.

Composition Design of Ni-Nano-Cu-BTC@Ag Coatings with Low Friction and Their Intelligent Electrical Control Behavior.

At present, Ni-based coatings are rarely used in the field of voltage control friction because of their poor antifriction, wear resistance, and conductive properties. Therefore, in this paper, Cu-BTC@Ag nanocrystals were used to enhance the nickel coatings, and the effect of voltage on their tribological properties was also investigated. It was found that the grains of coating were refined via the addition of Cu-BTC@Ag nanocrystals, leading to an improvement in the hardness and corrosion resistance of this composite coating. The tribological performance of nickel composite coating could be controlled under different electrical fields. With the comparison of the pure Ni-based coating, the average friction coefficient and wear volume of its composite coating with 5 wt % Cu-BTC@Ag were reduced by 7.0 and 91.8%, respectively, which showed excellent wear resistance without an applied voltage. Under the condition of 20 V, the 5 wt % Cu-BTC@Ag/Ni-based composite coating owned outstanding antifriction performance. Therefore, Cu-BTC@Ag played an intelligent role in regulating the friction of Ni-based coatings under an external voltage. It is due to the accumulation of Cu-BTC@Ag nanocrystals on the surface of the coating under the action of voltage, which played the role of supporting load and effectively reducing wear.

Detecting horizontal gene transfer with metagenomics co-barcoding sequencing.

Horizontal gene transfer (HGT) is the process through which genetic information is transferred between different genomes and that played a crucial role in bacterial evolution. HGT can enable bacteria to rapidly acquire antibiotic resistance and bacteria that have acquired resistance is spreading within the microbiome. Conventional methods of characterizing HGT patterns include short-read metagenomic sequencing (short-reads mNGS), long-read sequencing, and single-cell sequencing. These approaches present several limitations, such as short-read fragments, high amounts of input DNA, and sequencing costs, respectively. Here, we attempt to circumvent present limitations to detect HGT by developing a metagenomics co-barcode sequencing workflow (MECOS) and applying it to the human and mouse gut microbiomes. In addition to that, we have over 10-fold increased contig length compared to short-reads mNGS; we also obtained exceeding 30 million paired reads with co-barcode information. Applying the novel bioinformatic pipeline, we integrated this co-barcoding information and the context information from long reads, and observed over 50-fold HGT events after we corrected the potential wrong HGT events. Specifically, we detected approximately 3,000 HGT blocks in individual samples, encompassing ~6,000 genes and ~100 taxonomic groups, including loci conferring tetracycline resistance through ribosomal protection. MECOS provides a valuable tool for investigating HGT and advance our understanding on the evolution of natural microbial communities within hosts.IMPORTANCEIn this study, to better identify horizontal gene transfer (HGT) in individual samples, we introduce a new co-barcoding sequencing system called metagenomics co-barcoding sequencing (MECOS), which has three significant improvements: (i) long DNA fragment extraction, (ii) a special transposome insertion, (iii) hybridization of DNA to barcode beads, and (4) an integrated bioinformatic pipeline. Using our approach, we have over 10-fold increased contig length compared to short-reads mNGS, and observed over 50-fold HGT events after we corrected the potential wrong HGT events. Our results indicate the presence of approximately 3,000 HGT blocks, involving roughly 6,000 genes and 100 taxonomic groups in individual samples. Notably, these HGT events are predominantly enriched in genes that confer tetracycline resistance via ribosomal protection. MECOS is a useful tool for investigating HGT and the evolution of natural microbial communities within hosts, thereby advancing our understanding of microbial ecology and evolution.

Prevention of high-fat-diet-induced obesity in mice by soluble dietary fiber from fermented and unfermented millet bran.

Obesity-related diabetes, cardiovascular disease, and hypertension pose many risks to human health. Thus, mice on a high-fat diet were gavaged with millet bran (unfermented/fermented) soluble dietary fiber (RSDF/FSDF, 500 mg·kg-1) for 10 weeks in current research, and then evaluated the various biological indicators. These findings revealed that RSDF and FSDF supplements could prevent fat synthesis by inhibiting sterol regulatory element-binding protein-1c gene expression. The RSDF supplements can also accelerate fat catabolism through enhanced the mRNA expression levels of adipose triglyceride lipase and peroxisome proliferator-activated receptor α. FSDF supplements can prevent obesity by decreasing 3-hydroxy-3-methyl-glutaryl-CoA reductase expression and increasing cholesterol 7α-hydroxylase expression. Moreover, FSDF also controls obesity development by lowering total cholesterol and low-density lipoprotein cholesterol levels in the blood, triglyceride, total cholesterol, and bile acid levels in the liver. Notably, FSDF supplements can promote Bacteroides and Prevotella propagation; excretive propionic acid binds to free fatty acid receptor 2/3 and then stimulates intestinal epithelial cells to generate glucagon-like-peptide-1 and peptide YY, which can reduce food and energy intake and ultimately prevent obesity. All evidence suggests that FSDF supplements play a crucial role in preventing obesity.

Non-targeted Metabolomics Analysis Reveals Distinct Metabolic Profiles Between Positive and Negative Emotional Tears of Humans: A Preliminary Study.

Background Basal, reflex, and emotional tears differ in chemical components. It is not yet known whether chemical differences exist in tears of different emotions. We investigated the biochemical basis of emotional tears by performing non-targeted metabolomics analyses of positive and negative emotional tears of humans. Methods Samples of reflex, negative, and positive emotional tears were obtained from 12 healthy college participants (11 females and one male). Untargeted metabolomics was performed to identify metabolites in different types of tears. The differentially altered metabolites were screened and assessed using univariate and multivariate analyses. Results The orthogonal partial least squares discriminant analysis model showed that reflex, negative, and positive emotional tears were clearly separated. A total of 133 significantly differentially expressed metabolites of electrospray ionization source (ESI-) mode were identified between negative and positive emotional tears. The top 50 differentially expressed metabolites between negative and positive emotional tears were highly correlated. Pathway analysis revealed that secretion of negative emotional tears was associated with some synapses in the brain, regulation of a series of endocrine hormones, including the estrogen signaling pathway, and inflammation activities, while secretion of positive emotional tears was correlated with biotin and caffeine metabolism. Conclusions It is indicated that metabolic profiles of reflex, positive, and negative emotional tears of humans are distinct, and secretion of the tears involves distinct biological activities. Therefore, we present a chemical method for detecting human emotions, which may become a powerful tool for the diagnosis of mental diseases and the identification of fake tears.

Feasibility and safety of Post-Urgent PCI Same-DaY discharge (PUSDY Trial) in China: protocol for a multicentre randomised controlled trial.

INTRODUCTION: In the Chinese healthcare system, where there is overcrowding in hospitals, especially in tertiary care centres, adoption of same-day discharge (SDD) post-percutaneous coronary intervention (PCI) could potentially lead to significant savings of healthcare resources and costs. This study is a non-inferiority trial examining whether post-PCI SDD is feasible in China. The primary hypothesis is that patient outcomes in post-urgent PCI SDD patients are non-inferior to regular discharge patients. METHODS AND ANALYSIS: Post-Urgent PCI Same-DaY is an investigator-initiated multicentre randomised unblinded clinical non-inferiority trial, with 1:1 centralised randomisation to the SDD or usual care (UC) group. Based on sample size calculations, 1296 patients from at least three hospitals, with mild to moderate myocardial infarction, will be included, and acute coronary syndrome patients will be excluded. All patients will receive UC while patients assigned to the SDD group will be discharged on the same day or within 12 hours post-PCI. The primary outcome is major adverse cardiovascular and cerebrovascular events 30 days after discharge. The secondary outcomes are all-cause mortality, bleeding and access site complications. The outcome rates will be compared between groups with the absolute risk difference with a 95% CI. ETHICS AND DISSEMINATION: The study protocol V.2.0 has been approved on 21 January 2022 by the Ethics Committee of Beijing Anzhen Hospital, Capital Medical University (approval number: 2021 KLSD No. 23). The outcomes of this study will be disseminated through a peer-reviewed journal and presented at international conferences. TRIAL REGISTRATION NUMBER: ChiCTR 2200057065; China Clinical Trial Registration.

Hemoglobin-to-Red Cell Distribution Width Ratio is Associated with All-Cause Mortality in Critically Ill Patients with Traumatic Brain Injury.

BACKGROUND: Hemoglobin-to-red cell distribution width ratio (HRR) has shown good prognostic value in various cancers. However, the relationship between HRR and outcomes in critically ill patients with traumatic brain injury (TBI) remains unclear. This study aimed to investigate the association between HRR and mortality among critically ill patients with TBI. METHODS: The Medical Information Mart for Intensive Care-IV (MIMIC-IV) database was utilized to conduct this retrospective cohort study. TBI patients were divided into four quartiles according to their HRR values. The primary outcome was 30-day mortality, whereas the secondary outcomes were 60-day and 120-day mortality. Univariable and multivariable Cox proportional risk models were performed to evaluate the hazard ratio (HR) and 95% confidence interval (CI) for the relationship between HRR and mortality. Receiver operating characteristic (ROC) curves were conducted to assess the prognostic value of HRR. RESULTS: For 30-day mortality, after adjustment for all potential covariates, the relationship remained significant with HRR treated as a continuous variable (HR, 95% CI: 0.87 [0.81, 0.92]; p < 0.001). In the fully adjusted model, the HR with 95% CI for the second, third, and fourth quartile groups were 0.67 (0.5, 0.9), 0.65 (0.46, 0.94), and 0.5 (0.32, 0.79), respectively, compared to the first quartile group. A similar relationship was also observed for 60-day mortality and 120-day mortality. HRR had a better predictive value than hemoglobin and red cell distribution width (RDW). CONCLUSIONS: A lower level of HRR is significantly associated with higher all-cause mortality among critically ill patients with TBI.

Electronic-Control Friction Behavior of Porous Metal-Organic Framework@Ag Nanocrystals as Self-Repairing Lubricant Additive.

The low conductivity and poor antifriction performance of lubricants are the main causes of wear failure in mechanical equipment under electronic-control friction. Metal-organic framework (MOF) nanocomposites can be used to fabricate a new kind of lubricant additive. Herein, porous Cu-BTC@Ag MOF nanocrystals were successfully synthesized via an in situ generation method. Transmission electron microscopy results showed that the nano-Ag element was evenly dispersed throughout the Cu-BTC matrix. Cu-BTC@Ag nanocrystals can significantly improve the electrical conductivity of the EMI-BF4 ionic liquid, which increased by 38.8%. The average coefficients of friction (COF) and wear volume of EMI-BF4 ionic liquid with 0.5 wt % Cu-BTC@Ag decreased by 8.3 and 16% without applied voltage, respectively. This finding was due to the continuous extrusion of the EMI-BF4 stored in the Cu-BTC@Ag pores under external load. It entered the contact zone, thereby maintaining the continuous supply of lubricant. At 20 V applied voltage in the friction process, the COF of the EMI-BF4/2.0wt %Cu-BTC@Ag lubricant decreased by 18.8%, and its wear volume decreased by 32.7%. The Cu-BTC@ Ag nanocrystals adsorbed onto the metal surface to form a friction reaction film by the action of electric fields, which can repair the wear defects on the friction interface. Therefore, Cu-BTC@Ag nanocrystals acting as an additive in lubricant have remarkable prospects in the area of electronic-control friction.

An Evidential Multi-Target Domain Adaptation Method Based on Weighted Fusion for Cross-Domain Pattern Classification.

For cross-domain pattern classification, the supervised information (i.e., labeled patterns) in the source domain is often employed to help classify the unlabeled target domain patterns. In practice, multiple target domains are usually available. The unlabeled patterns (in different target domains) which have high-confidence predictions, can also provide some pseudo-supervised information for the downstream classification task. The performance in each target domain would be further improved if the pseudo-supervised information in different target domains can be effectively used. To this end, we propose an evidential multi-target domain adaptation (EMDA) method to take full advantage of the useful information in the single-source and multiple target domains. In EMDA, we first align distributions of the source and target domains by reducing maximum mean discrepancy (MMD) and covariance difference across domains. After that, we use the classifier learned by the labeled source domain data to classify query patterns in the target domains. The query patterns with high-confidence predictions are then selected to train a new classifier for yielding an extra piece of soft classification results of query patterns. The two pieces of soft classification results are then combined by evidence theory. In practice, their reliabilities/weights are usually diverse, and an equal treatment of them often yields the unreliable combination result. Thus, we propose to use the distribution discrepancy across domains to estimate their weighting factors, and discount them before fusing. The evidential combination of the two pieces of discounted soft classification results is employed to make the final class decision. The effectiveness of EMDA was verified by comparing with many advanced domain adaptation methods on several cross-domain pattern classification benchmark datasets.

Association between obesity and short- and medium-term mortality in critically ill patients with atrial fibrillation: a retrospective cohort study.

BACKGROUND: There has been controversy about how obesity affects the clinical prognosis for patients with atrial fibrillation (AF), and the relationship between obesity and outcomes in critically ill patients with AF remains unclear. The purpose of this study was to explore the association between obesity and short- and medium-term mortality in critically ill patients with AF. METHODS: The Medical Information Mart for Intensive Care-IV (MIMIC-IV) database was used to conduct a retrospective cohort analysis on 9282 critically ill patients with AF. Patients were categorized into four groups based on their body mass index (BMI) values: underweight, normal-weight, overweight, and obese. The outcomes of this study were 30-day, 90-day, and 1-year all-cause mortality. Cox proportional-hazards models and restricted cubic spline analyses were performed to investigate the association between BMI and mortality. RESULTS: For 30-day mortality, after adjustment for all confounding factors, the hazard ratio (HR) with 95% confidence interval (CI) for the underweight, overweight, and obese categories were 1.58 (1.21, 2.07), 0.82 (0.72, 0.93), and 0.79 (0.68, 0.91), respectively, compared to the normal-weight category. Using multivariable-adjusted restricted cubic spline analysis, an "L-shaped" correlation was observed between BMI and 30-day mortality. For each 1 kg/m2 increase in BMI when BMI was less than 30 kg/m2, the risk of 30-day mortality decreased by 6.4% (HR, 95% CI: 0.936 [0.918, 0.954]; P < 0.001); however, this relationship was not present when BMI was greater than or equal to 30 kg/m2. Similar results were observed for 90-day and 1-year mortality. CONCLUSIONS: There was a nonlinear relationship between BMI and all-cause mortality among critically ill patients with AF. All-cause mortality and the BMI were negatively correlated when the BMI was less than 30 kg/m2.

Novel Mutations of PAX6 and WFS1 Associated With Congenital Cataract in a Chinese Family.

BACKGROUND: Congenital cataract is a common cause of blindness in childhood. About half of the cases have a genetic etiology, and more than 100 genes have been associated with congenital cataracts. This study reports the clinical and genetic findings of a two-generation Chinese family affected by congenital cataract. METHODS: Ophthalmologic examinations were performed for clinical evaluation of the cataract patients. Whole exome sequencing (WES) and Sanger sequencing were used to identify potentially relevant mutations. The online programsProtein Variation Effect Analyzer (PROVEAN) and Sorting Intolerant from Tolerant (SIFT) were employed to predict the impact of variation on protein function. RESULTS: Both the proband and her mother were blind because of bilateral nuclear cataracts, and the elder brother of the proband also manifested obvious bilateral cataracts. Sanger sequencing confirmed the mutations in the proband as well as in her mother. The elder brother simply carried the PAX6 c.221G>A variation. The WFS1 c.2070_2079del variation potentially generates a loss-of-function mutant. CONCLUSION: The novel PAX6mutation (c.221G>A) is associated with congenital cataract, and the WFS1 mutation (c.2070_2079del) may interactively aggravates this process. These findings may increase our understanding of the genetic etiology of congenital cataract.

Research on the main methods of core strength training in sprinters / Pesquisa sobre os principais métodos de treino de força do core em velocistas / Investigación sobre los principales métodos de entrenamiento de fuerza del core en velocistas

ABSTRACT Introduction With the development of increasingly competitive sports, coaches began experimenting with new methods for training athletes. Although among the most explored training methods is core strength training, a set of muscle groups that stabilize the trunk and hips, there are few studies on the effectiveness of this training dedicated to sprinters. Objective This paper investigates the training method of sprinters based on core strength training, studying the method and its influence on athletes' performance. Methods Sixteen athletes with similar technical levels and physical fitness were selected, and professional coaches were invited to test the training samples. The athletes were randomly assigned to the experimental and control group (8 in each). The experimental group received core strength training for eight weeks, while the control group received general training. Results Off-core training affected the ankle joint angle of the support leg and the ankle joint angle of the swing leg (P < 0.01). After eight weeks of training, the performance of both groups improved without considerable differences. The high jump results of the athletes in the experimental group also improved compared to the previous training. Conclusion The physical function of athletes can be improved through core strength training to improve the sprinters' competitive level and technical ability. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução Com o desenvolvimento de esportes cada vez mais competitivos, os treinadores começaram a experimentar novos métodos para a formação de atletas. Embora entre os métodos de treinamento mais explorados encontra-se o treino do core, conjunto de grupos musculares estabilizadores do tronco e quadril, há poucos estudos sobre a efetividade desse treino dedicado a atletas velocistas. Objetivo Este artigo investiga o método de treino de velocistas baseado no treinamento de força do core, estudando o método e a influência no desempenho do atleta. Métodos Foram selecionados 16 atletas com nível técnico e aptidão física similares, treinadores profissionais foram convidados a testar as amostras de treino. Os atletas foram aleatoriamente designados para o grupo experimental e controle (8 em cada). O grupo experimental recebeu treinamento de força do core por 8 semanas, enquanto o grupo controle recebeu treinamento geral. Resultados O treinamento de fora do core teve um efeito no ângulo da articulação do tornozelo da perna de apoio e no ângulo da articulação do tornozelo da perna de balanço (P < 0,01). Após oito semanas de treinamento, o desempenho de ambos grupos melhoraram sem diferenças consideráveis. Os resultados do salto em altura dos atletas do grupo experimental também melhoraram em relação ao treinamento anterior. Conclusão A função física dos atletas pode ser aprimorada através do treinamento de força do core, de modo a melhorar ainda mais o nível competitivo e a capacidade técnica dos velocistas. Nível de evidência II; Estudos terapêuticos - investigação dos desfechos do tratamento.

RESUMEN Introducción Con el desarrollo de deportes cada vez más competitivos, los entrenadores comenzaron a experimentar nuevos métodos para el entrenamiento de los atletas. Aunque entre los métodos de entrenamiento más explorados se encuentra el entrenamiento del core, un conjunto de grupos musculares que estabilizan el tronco y las caderas, hay pocos estudios sobre la eficacia de este entrenamiento dedicado a los atletas velocistas. Objetivo Este artículo investiga el método de entrenamiento de los velocistas basado en el entrenamiento de la fuerza del core, estudiando el método y la influencia en el rendimiento del atleta. Métodos Se seleccionaron dieciséis atletas con un nivel técnico y una aptitud física similares, y se invitó a entrenadores profesionales a probar las muestras de entrenamiento. Los atletas fueron asignados aleatoriamente al grupo experimental y al de control (8 en cada uno). El grupo experimental recibió un entrenamiento del core durante 8 semanas, mientras que el grupo de control recibió un entrenamiento general. Resultados El entrenamiento fuera del core tuvo un efecto sobre el ángulo de la articulación del tobillo de la pierna de apoyo y el ángulo de la articulación del tobillo de la pierna de impulso (P < 0,01). Tras ocho semanas de entrenamiento, el rendimiento de ambos grupos mejoró sin diferencias considerables. Los resultados del salto de altura de los atletas del grupo experimental también mejoraron en relación con el entrenamiento anterior. Conclusión La función física de los atletas velocistas puede mejorarse mediante el entrenamiento del core, con el fin de mejorar aún más su nivel competitivo y su capacidad técnica. Nivel de evidencia II; Estudios terapéuticos: investigación de los resultados del tratamiento.

Relationship between red blood cell distribution width-to-albumin ratio and outcome of septic patients with atrial fibrillation: a retrospective cohort study.

BACKGROUND: This retrospective cohort study aimed to investigate the association between red blood cell distribution width-to-albumin ratio (RAR) and in-hospital mortality in patients with sepsis and atrial fibrillation (AF). METHODS: Data were obtained from the Medical Information Mart for the Intensive Care Database IV database version 1.0. Multivariate Cox regression models, curve-fitting, and Kaplan-Meier analyses were performed to determine the correlation between RAR and in-hospital mortality in patients with sepsis and AF. RESULTS: This study included 3042 patients with sepsis and AF. Confounding variables were adjusted for in the Multivariable Cox regression analysis models. RAR was independently associated with in-hospital mortality (hazard ratio 1.06; 95% confidence interval 1.03-1.08; p < 0.001). A linear relationship was found between the RAR and in-hospital mortality in patients with sepsis and AF. CONCLUSION: Elevated RAR levels are associated with increased in-hospital mortality in patients with sepsis and AF. Further research is required to confirm this association.

Role of the fsr Quorum-Sensing System in Enterococcus faecalis Bloodstream Infection.

Enterococcus faecalis is an important intestinal colonizing bacteria and can cause various tissue infections, including invasive blood infection (BI). The annual incidence of E. faecalis BI has been estimated to be ~4.5 per 100,000, with a fatality rate that can reach 20%. However, whether bacterial colonization or invasive infections are tissue based has not been thoroughly studied. In this study, we analyzed 537 clinical isolates from 7 different tissues to identify the key genomic elements that facilitate the colonization and invasive infection of E. faecalis. Comparative genomic analysis revealed that the BI E. faecalis isolates had the largest genome size but the lowest GC content, fsr quorum-sensing system genes were enriched in the BI E. faecalis, and the fsr gene cluster could enhance biofilm formation and serum resistance ability. Our findings also provide deep insight into the genomic differences between different tissue isolates, and the fsr quorum-sensing systems could be a key factor promoting E. faecalis invasion into the blood. IMPORTANCE First, we conducted an advanced study on the genomic differences between colonizing and infecting E. faecalis, which provides support and evidence for early and accurate diagnoses. Second, we discovered that fsr was significantly associated with blood infections, which also provides additional information for studies exploring the invasiveness of E. faecalis. Most importantly, we found that fsr played an important role in both biofilm formation and serum resistance ability in E. faecalis.

Tree-based, two-stage risk factor analysis for postoperative sepsis based on Sepsis-3 criteria in elderly patients: A retrospective cohort study.

Background: Sepsis remains the leading cause of postoperative death in elderly patients and is defined as organ dysfunction with proven or suspected infection according to Sepsis-3 criteria. To better avoid potential non-linear associations between the risk factors, we firstly used a tree-based analytic methods to explore the putative risk factors of geriatric sepsis based on the criteria in the study. Methods: Data of 7,302 surgical patients aged ≥ 65 years at the Third Affiliated Hospital of Sun Yat-sen University from January 2015 to September 2020 were collected. An analytic method that combined tree-based analysis with the method of Mantel-Haenszel and logistic regression was adopted to assess the association between 17 putative risk factors and postoperative sepsis defined by the Sepsis-3 guideline by controlling 16 potential confounding factors. Results: Among the 16 potential covariates, six major confounders were statistically identified by the tree-based model, including cerebrovascular diseases, preoperative infusion of red blood cells, pneumonia, age ≥ 75, malignant tumor and diabetes. Our analysis indicated that emergency surgery increases the risk of postoperative sepsis in elderly patients by more than six times. The type of surgery is also a crucial risk factor for sepsis, particularly transplantation and neurosurgery. Other risk factors were duration of surgery > 120 min, administration of steroids, hypoalbuminemia, elevated creatinine, blood urea nitrogen, hematocrit, platelets, glucose, white blood cell count, abnormal neutrophil-to-lymphocyte ratio and elevated hsCRP-to-albumin ratio. Conclusions: Our study uses an effective method to explore some risk factors for postoperative sepsis in elderly by adjusting many potential confounders and it can provide information for intervention design.

Multi-omics provide mechanistic insight into the Pb-induced changes in tadpole fitness-related traits and environmental water quality.

Water pollution from lead/Pb2+ poses a significant threat to aquatic ecosystems, and its repercussions on aquatic animals have received considerable attention. Although Pb2+ has been found to affect numerous aspects of animals, including individual fitness, metabolic status, and symbiotic microbiota, few studies have focused on the associations between Pb2+-induced variations in fitness, metabolome, symbiotic microbiome, and environmental parameters in the same system, limiting a comprehensive understanding of ecotoxicological mechanisms from a holistic perspective. Moreover, most ecotoxicological studies neglected the potential contributions of anions to the consequences generated by inorganic lead compounds. We investigated the effects of Pb(NO3)2 at environmentally relevant concentrations on the Rana omeimontis tadpoles and the water quality around them, using blank and NaNO3-treated groups as control. Results showed that Pb(NO3)2 not only induced a rise in water nitrite level, but exposure to this chemical also impaired tadpole fitness-related traits (e.g., growth and development). The impacts on tadpoles were most likely a combination of Pb2+ and NO3-. Tissue metabolomics revealed that Pb(NO3)2 exposure influenced animal substrate (i.e., carbohydrate, lipid, and amino acid) and prostaglandin metabolism. Pb(NO3)2 produced profound shifts in gut microbiota, with increased Proteobacteria impairing Firmicutes, resulting in higher aerobic and possibly pathogenic bacteria. NaNO3 also influenced tadpole metabolome and gut microbiome, in a manner different to that of Pb(NO3)2. The presence of NO3- seemed to counteract some changes caused by Pb2+, particularly on the microbiota. Piecewise structural equation model and correlation analyses demonstrated connections between tissue metabolome and gut microbiome, and the variations in tadpole phenotypic traits and water quality were linked to changes in tissue metabolome and gut microbiome. These findings emphasized the important roles of gut microbiome in mediating the effects of toxin on aquatic ecosystem. Moreover, it is suggested to consider the influences of anions in the risk assessment of heavy metal pollutions.

The Characteristic and Distribution of Shale Micro-Brittleness Based on Nanoindentation.

Shale is a special kind of rock mass and it is particularly important to evaluate its brittleness for the extraction of gas and oil from nanoporous shale. The current brittleness studies are mostly macro-evaluation methods, and there is a lack of a micro-brittleness index that is based on nanoindentation tests. In this paper, nanoindentation tests are carried out on the surface of shale to obtain mechanical property, and then a novel micro-brittleness index is proposed. Drawing a heat map by meshing indentation, the distribution characteristics of the brittleness index for the surface of shale and the variation laws between the mineral and brittleness index are explored. The results showed that the dimensionless brittleness index involved parameters including indentation irreversible deformation, elastic modulus, hardness and fracture toughness. The micro-brittleness index of the shale ranged from 7.46 to 65.69, and the average brittleness index was 25.837. The brittleness index exhibited an obvious bimodal distribution and there was great heterogeneity on the surface of shale. The crack propagation channels were formed by connecting many indentation points on the shale surface with high brittleness. The total brittleness index of quartz minerals was high, but the cementation effect with different minerals was various. Although the general brittleness of clay was low, the high brittleness index phenomenon was also exhibited. Studying the micro-brittleness of shale provides a more detailed evaluation for the shale friability, which is used to determine the optimal shale oil and gas recovery regime.