Double-Phase-Networking Polyimide Hybrid Aerogel with Exceptional Dimensional Stability for Superior Thermal Protection System.

Polyimide aerogels have been extensively used in thermal protection domain because they possess a combination of intrinsic characteristics of aerogels and unique features of polyimide. However, polyimide aerogels still suffer significant thermally induced shrinkage at temperatures above 200 °C, restricting their application at high temperature. Here, a novel "double-phase-networking" strategy is proposed for fabricating a lightweight and mechanically robust polyimide hybrid aerogel by forming silica-zirconia-phase networking skeletons, which possess exceptional dimensional stability in high-temperature environments and superior thermal insulation. The rational mechanism responsible for the formation of double-phase-networking aerogel is further explained, generally attributing to chemical crosslinking reactions and supramolecular hydrogen bond interactions derived from the main chains of polyimide and silane/zirconia precursor/sol. The as-prepared aerogels exhibit excellent high-temperature (270 °C) dimensional stability (5.09% ± 0.16%), anti-thermal-shock properties, and low thermal conductivity. Moreover, the hydrophobic treatment provides aerogels high water resistance with water contact angle of 136.9°, further suggestive of low moisture content of 3.6% after exposure to 70 °C and 85% relative humidity for 64 h. The proposed solution for significantly enhancing high-temperature dimensional stability and thermal insulation provides a great supporting foundation for fabricating high-performance organic aerogels as thermal protection materials in aerospace.

Long-term outcomes of pelvic exenterations for gynecological malignancies: a single-center retrospective cohort study.

BACKGROUND: Recently, with the advancement of medical technology, the postoperative morbidity of pelvic exenteration (PE) has gradually decreased, and it has become a curative treatment option for some patients with recurrent gynecological malignancies. However, more evidence is still needed to support its efficacy. This study aimed to explore the safety and long-term survival outcome of PE and the feasibility of umbilical single-port laparoscopic PE for gynecologic malignancies in a single medical center in China. PATIENTS AND METHODS: PE for gynecological cancers except for ovarian cancer conducted by a single surgical team in Sun Yat-sen University Cancer Center between July 2014 and December 2019 were included and the data were retrospectively analyzed. RESULTS: Forty-one cases were included and median age at diagnosis was 53 years. Cervical cancer accounted for 87.8% of all cases, and most of them received prior treatment (95.1%). Sixteen procedures were performed in 2016 and before, and 25 after 2016. Three anterior PE were performed by umbilical single-site laparoscopy. The median operation time was 460 min, and the median estimated blood loss was 600 ml. There was no perioperative death. The years of the operations was significantly associated with the length of the operation time (P = 0.0018). The overall morbidity was 52.4%, while the severe complications rate was 19.0%. The most common complication was pelvic and abdominal infection. The years of surgery was also significantly associated with the occurrence of severe complication (P = 0.040). The median follow-up time was 55.8 months. The median disease-free survival (DFS) was 17.9 months, and the median overall survival (OS) was 25.3 months. The 5-year DFS was 28.5%, and the 5-year OS was 30.8%. CONCLUSION: PE is safe for patient who is selected by a multi-disciplinary treatment, and can be a curative treatment for some patients. PE demands a high level of experience from the surgical team. Umbilical single-port laparoscopy was a technically feasible approach for APE, meriting further investigation.

RhIII-Catalyzed Direct Heteroarylation of Unactivated C(sp3)-H with N-Heteroaryl Boronates.

Disclosed herein is a rhodium(III)-catalyzed direct heteroarylation reaction between unactivated aliphatic C(sp3)-H bonds in 2-alkylpyridines and heteroaryl organoboron reagents. This catalytic protocol is compatible with various heterocyclic boronates containing ortho- and meta-pyridine, pyrazoles, furan, and quinoline with strong coordination capability. The achievement of this methodology provides an efficient route to build new C(sp3)-heteroaryl bonds.

Chondrocyte-targeted exosome-mediated delivery of Nrf2 alleviates cartilaginous endplate degeneration by modulating mitochondrial fission.

BACKGROUND: Cartilaginous endplate (CEP) degeneration, which is an important contributor to intervertebral disc degeneration (IVDD), is characterized by chondrocyte death. Accumulating evidence has revealed that dynamin-related protein 1 (Drp1)-mediated mitochondrial fission and dysfunction lead to apoptosis during CEP degeneration and IVDD. Exosomes are promising agents for the treatment of many diseases, including osteoporosis, osteosarcoma, osteoarthritis and IVDD. Despite their major success in drug delivery, the full potential of exosomes remains untapped. MATERIALS AND METHODS: In vitro and in vivo models of CEP degeneration were established by using lipopolysaccharide (LPS). We designed genetically engineered exosomes (CAP-Nrf2-Exos) expressing chondrocyte-affinity peptide (CAP) on the surface and carrying the antioxidant transcription factor nuclear factor E2-related factor 2 (Nrf2). The affinity between CAP-Nrf2-Exos and CEP was evaluated by in vitro internalization assays and in vivo imaging assays. qRT‒PCR, Western blotting and immunofluorescence assays were performed to examine the expression level of Nrf2 and the subcellular localization of Nrf2 and Drp1. Mitochondrial function was measured by the JC-1 probe and MitoSOX Red. Mitochondrial morphology was visualized by MitoTracker staining and transmission electron microscopy (TEM). After subendplate injection of the engineered exosomes, the degree of CEP degeneration and IVDD was validated radiologically and histologically. RESULTS: We found that the cargo delivery efficiency of exosomes after cargo packaging was increased by surface modification. CAP-Nrf2-Exos facilitated chondrocyte-targeted delivery of Nrf2 and activated the endogenous antioxidant defence system in CEP cells. The engineered exosomes inhibited Drp1 S616 phosphorylation and mitochondrial translocation, thereby preventing mitochondrial fragmentation and dysfunction. LPS-induced CEP cell apoptosis was alleviated by CAP-Nrf2-Exo treatment. In a rat model of CEP degeneration, the engineered exosomes successfully attenuated CEP degeneration and IVDD and exhibited better repair capacity than natural exosomes. CONCLUSION: Collectively, our findings showed that exosome-mediated chondrocyte-targeted delivery of Nrf2 was an effective strategy for treating CEP degeneration.

Evaluation of the modified MRI vertebral bone quality score for bone quality in lumbar degenerative disorders.

OBJECTIVE: The traditional VBQ scoring method may lead to overestimation due to the concentration of intravertebral fat and vascular structures in the posterior half of vertebral bodies, potentially resulting in false-positive outcomes. This study aims to modify the measurement method of VBQ score (Modified-VBQ) and evaluate its effectiveness in evaluating bone quality of lumbar degenerative diseases. METHODS: Retrospective analysis was conducted on clinical data from patients undergoing lumbar surgery for degenerative diseases between September 2022 and September 2023. Preoperative lumbar t1-weighted Magnetic resonance imaging was used for both modified and traditional VBQ scoring. Computed tomography (CT) images and dual-energy X-ray absorptiometry (DEXA) data were collected through the picture archiving and communication system. The effectiveness of the modified VBQ score was evaluated, considering P < 0.05 as statistically significant. RESULTS: The study included 212 patients, revealing a significant difference between the modified VBQ and VBQ scores (P < 0.0001). Notably, patients with a history of hyperlipidemia exhibited a significant difference between the two scores (P = 0.0037). The area under the ROC curve (AUC) for the modified VBQ was 0.86, surpassing the VBQ score (AUC = 0.74). Linear regression analysis demonstrated a moderate to strong correlation between the modified VBQ and DEXA T-score (r = - 0.49, P < 0.0001) and a high correlation with CT Hounsfield units (HU) values (r = - 0.60, P < 0.0001). CONCLUSION: The modified VBQ score provides a simple, effective, and relatively accurate means of assessing bone quality in lumbar degenerative diseases. Preoperative implementation of the modified VBQ score facilitates rapid screening for patients with abnormal bone quality.

Subsurface acoustic ducts in the Northern California current system.

This study investigates the subsurface sound channel or acoustic duct that appears seasonally along the U.S. Pacific Northwest coast below the surface mixed layer. The duct has a significant impact on sound propagation at mid-frequencies by trapping sound energy and reducing transmission loss within the channel. A survey of the sound-speed profiles obtained from archived mooring and glider observations reveals that the duct is more prevalent in summer to fall than in winter to spring and offshore of the shelf break than over the shelf. The occurrence of the subsurface duct is typically associated with the presence of a strong halocline and a reduced thermocline or temperature inversion. Furthermore, the duct observed over the shelf slope corresponds to a vertically sheared along-slope velocity profile, characterized by equatorward near-surface flow overlaying poleward subsurface flow. Two potential duct formation mechanisms are examined in this study, which are seasonal surface heat exchange and baroclinic advection of distinct water masses. The former mechanism regulates the formation of a downward-refracting sound-speed gradient that caps the duct near the sea surface, while the latter contributes to the formation of an upward-refracting sound-speed gradient that defines the duct's lower boundary.

A triphenylamine-based fluorescent probe with phenylboronic acid for highly selective detection of Hg2+ and CH3Hg+ in groundwater.

Mercury is a highly toxic heavy metal and it poses a serious threat to the natural environment and human health. Thus, selective detection of trace mercury (e.g. inorganic mercury and methylmercury) in the environment is critical yet challenging. Herein, we describe the rational design and facile synthesis of a new triphenylamine-based phenylboronic acid fluorescent probe (TPA-PBA) for selective detection of Hg2+ and CH3Hg+. Due to the inherent specificity of the displacement reaction between phenylboronic acid and mercury, this probe exhibits exceptionally high selectivity towards Hg2+/CH3Hg+ against other tested ions with ppb-level sensitivity. More importantly, the probe TPA-PBA is effective and selective in detecting Hg2+/CH3Hg+ in tap water and real-world groundwater, indicating its potential practical applications in in situ and online mercury detection in real-world scenarios. With TPA-PBA based test strips Hg2+ can be distinguished from CH3Hg+ by the naked eye. This study could accelerate the development of low-cost, highly efficient and selective fluorescent probes for rapid trace mercury detection.

Aromatics production from relay catalytic pyrolysis of cow manure using Ru/C and ZSM-5 dual catalysts synthesized from coal gasification fine slag.

Resource utilization of solid waste can aid in gradual substitution of fossil fuels while achieving waste recycling. In this study, residual carbon and ash slag from the coal gasification fine slag were separated by froth flotation, and then was used to prepare Ru/C and ZSM-5 dual catalysts with carbon-rich and ash-rich components as raw materials, respectively. The performance of two catalysts for catalytic upgrading of volatiles from pyrolysis of cow manure (CM) to produce light aromatic hydrocarbons was systematically investigated. The direct pyrolysis products of CM mainly included alcohols, ketones, ethers, and other oxygen-containing compounds. When ZSM-5 was used as the catalyst, the yield of monocyclic aromatic hydrocarbons (MAHs) increased significantly due to the better catalytic cracking and aromatization abilities of ZSM-5 catalyst. However, the yield of phenols in the pyrolysis products improved when Ru/C was used as the catalyst due to the cleavage effect of Ru/C on the C-O bond. When Ru/C and ZSM-5 were used as dual catalysts in relay catalytic pyrolysis of volatiles, the increase in MAHs yield in the pyrolysis product was higher than the total increase obtained under Ru/C and ZSM-5 single catalysis. The possible pathways for the generation of MAHs from CM under Ru/C and ZSM-5 relay catalytic pyrolysis were revealed by the pyrolysis experiment performed on model compounds.

Cell-Free Extracts from Human Fat Tissue with a Hyaluronan-Based Hydrogel Attenuate Inflammation in a Spinal Cord Injury Model through M2 Microglia/Microphage Polarization.

Treatment for spinal cord injuries (SCIs) is often ineffective because SCIs result in a loss of nerve tissue, glial scar formation, local ischemia and secondary inflammation. The current promising strategy for SCI is the combination of bioactive materials and cytokines. Bioactive materials support the injured spinal cord, stabilize the morphology, and avoid excessive inflammatory responses. Fat extract (FE) is a cell-free liquid component containing a variety of cytokines extracted from human fat tissue using mechanical methods. In this research, a biocompatible HAMC (hyaluronan and methylcellulose) loaded with FE is used to treat a model of spinal cord contusion in mice. The composite not only inhibits death of neuro- and vascular cells and leads to the preservation of neural and vascular structure, but also modulates the inflammatory phenotype of macrophages in the locally injured region. Specifically, FE promotes the polarization of macrophages from an inflammatory M1 phenotype to an anti-inflammatory M2 phenotype. During the screening of the involved pathways, it is corroborated that activation of the STAT6/Arg-1 signaling pathway is involved in macrophage M2 polarization. In summary, FE is a promising treatment for SCI, as it is easy to obtain, nonimmunogenic, and effective.

Ambient Pressure Drying to Construct Cellulose Acetate/Benzoxazine Hybrid Aerogels with Flame Retardancy, Excellent Thermal Stability, and Superior Mechanical Strength Resistance to Cryogenic Temperature.

Cellulose aerogels are highly attractive candidates in various applications, such as thermal insulation, adsorption separation, biomedical field, and as carriers, due to their intrinsic merits of low density, high porosity, biodegradability, and renewability. However, the expensive cost of the supercritical drying process and poor mechanical properties limit their practical applications. Herein, a new method was presented to fabricate cellulose acetate/benzoxazine hybrid aerogels (CBAs) with low cost, low drying shrinkage, excellent mechanical properties under cryogenic condition (-196 °C), outstanding thermal insulation, flame retardancy, and good thermal stability by ambient pressure drying. In more detail, the weighted drying shrinkage rate of CBAs-T2 can be controlled to 6.8% (the average value along the radial and axial directions), mainly due to the enhanced skeleton, by introducing polybenzoxazine networking chains. The resultant CBAs-T2 exhibit outstanding mechanical properties at room temperature because of the presence of the polybenzoxazine hybrid in the cellulose networking system. CBAs-T2 still have good mechanical properties even after subjecting them to liquid nitrogen treatment. In addition, the optimal value of thermal conductivity (0.033 W m-1 K-1) is gained easily because of the uniform cross-linking networking structure and small pore size. A superior flame retardance of CBAs-T2 is endowed to achieve self-extinguishment after ignition, which is attributed to the presence of the aromatic ring in the backbone structure. Moreover, the good thermal stability of CBAs-T2 is attributed to the fact that polybenzoxazine components could resist the decomposition of cellulose acetate and inhibit heat release during the combustion process. Our study would provide a novel method for obtaining biomass aerogels including the cellulose-based materials system with low drying shrinkage and superior mechanical properties despite bearing a cryogenic environment by the low-cost ambient pressure drying approach.

Nucleophilic functionalizations of indole derivatives using the aromatic Pummerer reaction.

Because of the electron-rich property of indoles, direct functionalization strategies towards indoles generally involve electrophilic substitutions. In this paper, an efficient protocol for nucleophilic hydroxylation, halogenation and esterification of indoles via the aromatic Pummerer process was developed. With the advantages of readily accessible starting materials, simple operation and mild conditions, this protocol should be of interest to synthetic scientists.

Toll-Like Receptor 4: A Promising Therapeutic Target for Alzheimer's Disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disease that primarily manifests as memory deficits and cognitive impairment and has created health challenges for patients and society. In AD, amyloid ß-protein (Aß) induces Toll-like receptor 4 (TLR4) activation in microglia. Activation of TLR4 induces downstream signaling pathways and promotes the generation of proinflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1ß (IL-1ß), which also trigger the activation of astrocytes and influence amyloid-dependent neuronal death. Therefore, TLR4 may be an important molecular target for treating AD by regulating neuroinflammation. Moreover, TLR4 regulates apoptosis, autophagy, and gut microbiota and is closely related to AD. This article reviews the role of TLR4 in the pathogenesis of AD and a range of potential therapies targeting TLR4 for AD. Elucidating the regulatory mechanism of TLR4 in AD may provide valuable clues for developing new therapeutic strategies for AD.

Inhibition of TGFß-activated protein kinase 1 ameliorates myocardial ischaemia/reperfusion injury via endoplasmic reticulum stress suppression.

Transforming growth factor ß-activated protein kinase 1 (TAK1) involves in various biological responses and is a key regulator of cell death. However, the role of TAK1 on acute myocardial ischaemia/reperfusion (MI/R) injury is unknown. We observed that TAK1 activation increased significantly after MI/R and hypoxia/reoxygenation (H/R), and we hypothesized that TAK1 has an important role in MI/R injury. Mice (TAK1 inhibiting by 5Z-7-oxozeaenol or silencing by AAV9 vector) were exposed to MI/R injury. Primary cardiomyocytes (TAK1 silencing by siRNA; and overexpressing TAK1 by adenovirus vector) were used to induce H/R injury model in vitro. Inhibition of TAK1 significantly decreased MI/R-induced myocardial infarction area, reduced cell death and improved cardiac function. Mechanistically, TAK1 silencing suppressed MI/R-induced myocardial oxidative stress and attenuated endoplasmic reticulum (ER) stress both in vitro and in vivo. In addition, the inhibition of ROS by NAC partially reversed the damage of TAK1 in vitro. Our study presents the first direct evidence that inhibition of TAK1 mitigated MI/R injury, and TAK1 mediated ROS/ER stress/apoptosis signal pathway is important for the pathogenesis of MI/R injury.

Correlation Analysis of Pathways and Operons of Helicobacter pylori Resistance Genes Using Bibliometrics.

BACKGROUND: Helicobacter pylori is a gram-negative bacterium infecting approximately 50% of the world's population. Antibiotic resistance in H. pylori has significantly increased due to the overuse and misuse of common antibiotics. Mutations in the 23S rRNA gene and other H. pylori genetic mutations have been identified as significant drivers in the emergence of resistance. Therefore, there is an urgent need for genetic analysis of H. pylori antibiotic resistance. METHODS: Published H. pylori resistance genes were collected from PubMed websites by bibliometrics. Pathway analysis and operon analysis were performed using the Kyoto Encyclopedia of Genes and Genomes (KEGG), the Database for Annotation, Visualization and Integrated Discovery (DAVID), and Database of prOkaryotic OpeRons (DOOR) databases to investigate pathways and biological functions of resistance genes and statistically discover novel resistance genes. RESULTS: A total of 148 genes were mined from the literature using bibliometrics, and 46 enriched pathways were identified using KEGG. Subsequently, 7 novel resistant genes of H. pylor, including HP0776, HP0192, HP0193, HP0475, HP1057, HP0632, and HP0633, were identified and predicted by functional enrichment analysis of pathways and operons. CONCLUSIONS: The discovery of these novel H. pylori resistance genes is of great significance to treat H. pylori-induced diseases and develop optimal treatment regimens. They also provide theoretical fundamentals for epidemiological prevention and strengthen our understanding of the molecular mechanism of H. pylori resistance to antibiotics.

[Decreased expression of CatSper1 in the sperm of varicocele rats and protective effect of L-carnitine].

OBJECTIVE: To investigate the expression of the sperm-specific cation channel (CatSper1) in the epididymal sperm of varicocele (VC) rats and the effect of L-carnitine (LC) on the CatSper1 level. METHODS: Seventy male rats were equally randomized into groups A (normal control), B (VC model control), C (VC treated with normal saline), D (VC treated with low-dose LC), E (VC treated with medium-dose LC), F (VC treated with high-dose LC), and G (VC treated by prolonged medication of high-dose LC). The VC model was established by partial ligation of the left renal vein. At 12 weeks after modeling, the model rats in group C were treated intragastrically with normal saline at 1 ml/kg/d, those in groups D, E and F with LC at 0.05, 0.1 and 0.2 g/kg/d respectively, all for 5 consecutive weeks, and those in group G with LC at 0.2 g/kg/d for 7 successive weeks. Then, all the animals were sacrificed and their epididymides harvested for obtainment of the semen parameters by computer-assisted semen analysis (CASA) and determination of the mRNA and protein expressions of CatSper1 in the sperm by RT-PCR and Western blot. RESULTS: Compared with the rats in group A, those in group B showed significantly decreased percentage of grade a+b sperm (P < 0.01), sperm viability (P < 0.01), sperm concentration (P < 0.01) and expressions of CatSper1 mRNA (1.44 ± 0.67 vs 0.71 ± 0.38, P < 0.01) and protein (1.87 ± 0.67 vs 0.84 ± 0.42, P < 0.01). In comparison with the animals in group C, those in the four LC intervention groups exhibited a markedly increased percentage of grade a+b sperm, sperm viability and mRNA and protein expressions of CatSper1, even more remarkably in groups F and G (P < 0.01). No statistically significant difference, however, was observed in sperm concentration between group C and the LC intervention groups (P > 0.05), nor in the mRNA and protein expressions of CatSper1 between groups F and G. CONCLUSIONS: The expression of CatSper1 is decreased in the epididymal sperm of varicocele rats, and L-carnitine can increase the sperm viability, percentage of grade a+b sperm and CatSper1 expression of the rats.

The combination of procalcitonin and C-reactive protein or presepsin alone improves the accuracy of diagnosis of neonatal sepsis: a meta-analysis and systematic review.

BACKGROUND: Sepsis is an important cause of neonatal morbidity and mortality; therefore, the early diagnosis of neonatal sepsis is essential. METHOD: Our aim was to compare the diagnostic accuracy of procalcitonin (PCT), C-reactive protein (CRP), procalcitonin combined with C-reactive protein (PCT + CRP) and presepsin in the diagnosis of neonatal sepsis. We searched seven databases to identify studies that met the inclusion criteria. Two independent reviewers performed data extraction. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), area under curve (AUC), and corresponding 95% credible interval (95% CI) were calculated by true positive (TP), false positive (FP), false negative (FN), and true negative (TN) classification using a bivariate regression model in STATA 14.0 software. The pooled sensitivity, specificity, PLR, NLR, DOR, AUC, and corresponding 95% CI were the primary outcomes. Secondary outcomes included the sensitivity and specificity in multiple subgroup analyses. RESULTS: A total of 28 studies enrolling 2661 patients were included in our meta-analysis. The pooled sensitivity of CRP (0.71 (0.63, 0.78)) was weaker than that of PCT (0.85 (0.79, 0.89)), PCT + CRP (0.91 (0.84, 0.95)) and presepsin (0.94 (0.80, 0.99)) and the pooled NLR of presepsin (0.06 (0.02, 0.23)) and PCT + CRP (0.10 (0.05, 0.19)) were less than CRP (0.33 (0.26, 0.42)), and the AUC for presepsin (0.99 (0.98, 1.00)) was greater than PCT + CRP (0.96 (0.93, 0.97)), CRP (0.85 (0.82, 0.88)) and PCT (0.91 (0.89, 0.94)). The results of the subgroup analysis showed that 0.5-2 ng/mL may be the appropriate cutoff interval for PCT. A cut-off value > 10 mg/L for CRP had high sensitivity and specificity. CONCLUSIONS: The combination of PCT and CRP or presepsin alone improves the accuracy of diagnosis of neonatal sepsis. However, further studies are required to confirm these findings.

Pathogenic Gene Screening of Mycobacterium tuberculosis by Literature Data Mining and Information Pathway Enrichment Analysis.

BACKGROUND: Recent studies have unraveled mutations which have led to changes in the original conformation of functional proteins targeted by frontline drugs against Mycobacterium tuberculosis. These mutations are likely responsible for the emergence of drug-resistant strains of M. tuberculosis. Identification of new therapeutic targets is fundamental to the development of novel anti-TB drugs. METHODS: Boost evolution analysis of interactome data with use of high-throughput biological experimental technologies provides opportunities for identification of pathogenic genes and for screening out novel therapeutic targets. RESULTS: In this study, we identified 584 proven pathogenic genes of M. tuberculosis and new pathogenic genes via bibliometrics and relevant websites such as PubMed, KEGG, and DOOR websites. We identified 13 new genes that are most likely to be pathogenic. CONCLUSIONS: This study may contribute to the discovery of new pathogenic genes and help unravel new functions of known pathogenic genes of M. tuberculosis.

High-Throughput Screening of Escherichia coli O157:H7 Pathogenic Genes via Pathway Enrichment and Operon Analysis.

BACKGROUND: About thirty thousand people globally die every day from infectious diarrhea, mostly caused by pathogenic Escherichia coli (E. coli) O157:H7. METHODS: In order to search for clinical diagnostic biomarkers and novel drug targets for infectious diarrhea, we used a bibliometric method to collect pathogenic genes of E. coli O157:H7 and performed a functional analysis of the important pathogenic genes by pathway enrichment and operon analysis. RESULTS: We found 364 pathogenic genes which may be involved in infection with E. coli O157:H7 including 50 new specific pathogenic genes. It is possible that these newly found pathogenic genes will be of great importance in the treatment of E. coli O157:H7 infected diseases and the discovery of novel diagnostic biomarkers. CONCLUSIONS: Our findings also lay a theoretical foundation for the control, diagnosis, and prognosis of pathogenic E. coli related diseases.

The relative effect of particles and turbulence on acoustic scattering from deep sea hydrothermal vent plumes revisited.

The relative importance of suspended particles and turbulence as backscattering mechanisms within a hydrothermal plume located on the Endeavour Segment of the Juan de Fuca Ridge is determined by comparing acoustic backscatter measured by the Cabled Observatory Vent Imaging Sonar (COVIS) with model calculations based on in situ samples of particles suspended within the plume. Analysis of plume samples yields estimates of the mass concentration and size distribution of particles, which are used to quantify their contribution to acoustic backscatter. The result shows negligible effects of plume particles on acoustic backscatter within the initial 10-m rise of the plume. This suggests turbulence-induced temperature fluctuations are the dominant backscattering mechanism within lower levels of the plume. Furthermore, inversion of the observed acoustic backscatter for the standard deviation of temperature within the plume yields a reasonable match with the in situ temperature measurements made by a conductivity-temperature-depth instrument. This finding shows that turbulence-induced temperature fluctuations are the dominant backscattering mechanism and demonstrates the potential of using acoustic backscatter as a remote-sensing tool to measure the temperature variability within a hydrothermal plume.

Bibliometric Screening of Helicobacter Pylori Pathogenic Genes Through Pathway Enrichment and Operon Analysis.

BACKGROUND: Helicobacter pylori is one of the most common pathogenic bacteria that causes chronic gastritis, peptic ulcers, and gastric cancer. It is very difficult to treat H. pylori bacterial infections, in part due to its polymorphisms. The objective of this study was to identify critical contributors to the pathogenicity of H. pylori bacteria through bibliometric screening of pathogenic genes. METHODS: The pathogenic genes of H. pylori strain 26695 were collected from major publication databases using the bibliometric approach. Information about the pathways, operons, and functions of these genes was obtained from the KEGG and DOOR databases. RESULTS: We inferred that HP0067, HP0069, HP1109, HP1036, and HP1037 are key pathogenic genes in H. pylori pathogenicity. These genes provided new targets for the clinical diagnosis and prognosis judgment of H. pylori. CONCLUSIONS: Finally, this study may serve as a model for other genomic level studies when more H. pylori genomes become available. These results lay a theoretical foundation for further studies on the detection of novel pathogenic genes and relevant clinical analyses.