The role and mechanism of hydrogen sulfide in liver fibrosis.

Hydrogen sulfide (H2S) is the third new gas signaling molecule in the human body after the discovery of NO and CO. Similar to NO, it has the functions of vasodilation, anti-inflammatory, antioxidant, and regulation of cell formation. Enzymes that can produce endogenous H2S, such as CSE, CSB, and 3-MST, are common in liver tissues and are important regulatory molecules in the liver. In the development of liver fibrosis, H2S concentration and expression of related enzymes change significantly, which makes it possible to use exogenous gases to treat liver diseases. This review summarizes the role of H2S in liver fibrosis and its complications induced by NAFLD and CCl4, and elaborates on the anti-liver fibrosis effect of H2S through the mechanism of reducing oxidative stress, inhibiting inflammation, regulating autophagy, regulating glucose and lipid metabolism, providing theoretical reference for further research on the treatment of liver fibrosis with H2S.

Immune Dysregulation in SARS-CoV-2 patients coinfected with Mycobacterium tuberculosis (Mtb) or HIV in China.

BACKGROUND: SARS-CoV-2 infections usually cause immune dysregulation in the human body. Studies of immunological changes resulting from coinfections with Mycobacterium tuberculosis (Mtb) or HIV are limited. METHODS: We conducted a retrospective study focusing on patients with COVID-19. A total of 550 patients infected with SARS-CoV-2 were enrolled in our study and categorized into four groups based on the presence of coinfections; 166 Delta-infected patients, among whom 103 patients had no coinfections, 52 who were coinfected with Mtb, 11 who were coinfected with HIV, and 384 Omicron-infected patients. By collecting data on epidemiologic information, laboratory findings, treatments, and clinical outcomes, we analyzed and compared clinical and immunological characteristics. RESULTS: Compared with those in the Delta group, the median white blood cell, CD4 + T-cell and B-cell counts were lower in the Mtb group and the HIV group. Except for those in the Omicron group, more than half of the patients in the three groups had abnormal chest CT findings. Among the three groups, there were no significant differences in any of the cytokines. Compared with those in the Delta group, the disease duration and LOS were longer in the Mtb group and the HIV group. For unvaccinated Delta-infected patients, in the Mtb and HIV groups, the number of B cells and CD4 + T cells was lower than that in the Delta group, with no significant difference in the LOS or disease duration. In the Mtb group, three (6%) patients presented with a disease duration greater than four months and had decreased lymphocyte and IL17A counts, possibly due to double infections in the lungs caused by SARS-CoV-2 and M. tuberculosis. CONCLUSIONS: We found that SARS-CoV-2 patients coinfected with Mtb or HIV exhibited a longer disease duration and longer LOS, with a decrease in B cells and CD4 + T cells, suggesting that these cells are related to immune function. Changes in cytokine levels suggest that coinfection with Mtb or HIV does not result in dysregulation of the immune response. Importantly, we discovered a chronic course of coinfection involving more than four months of Mtb and SARS-CoV-2 infection.

Tenofovir Alafenamide for Pregnant Chinese Women With Active Chronic Hepatitis B: A Multicenter Prospective Study.

BACKGROUND & AIMS: Data on long-term tenofovir alafenamide (TAF) therapy for pregnant women with active chronic hepatitis B (CHB) (immune clearance and reactivation phases, currently and previously diagnosed) and their infants are lacking. METHODS: Pregnant women with active CHB treated with TAF and tenofovir disoproxil fumarate (TDF) were enrolled in this multicenter prospective study, and infants received immunoprophylaxis. The primary outcomes were rates of adverse (safety) events in pregnant women and defects in infants and fetuses. The secondary outcomes were virologic responses in pregnant women, infants' safety, hepatitis B surface antigen (HBsAg) status, and growth conditions. RESULTS: One hundred three and 104 pregnant women were enrolled and 102 and 104 infants were born in the TAF and TDF groups, respectively. In the TAF group, the mean age, gestational age, alanine aminotransferase level, and viral loads at treatment initiation were 29.3 years, 1.3 weeks, 122.2 U/L, and 5.1 log10 IU/mL, respectively. TAF was well-tolerated, and the most common adverse event was nausea (29.1%) during a mean of 2 years of treatment. Notably, 1 (1.0%) TAF-treated pregnant woman underwent induced abortion due to noncausal fetal cleft lip and palate. No infants in either group had birth defects. In the TAF group, the hepatitis B e antigen seroconversion rate was 20.7% at postpartum month 6, infants had normal growth parameters, and no infants were positive for HBsAg at 7 months. The TDF group had comparable safety and effectiveness profiles. CONCLUSIONS: TAF administered throughout or beginning in early pregnancy is generally safe and effective for pregnant women with active CHB and their infants.

Influencing Factors of Recurrence of Nonvalvular Atrial Fibrillation after Radiofrequency Catheter Ablation and Construction of Clinical Nomogram Prediction Model.

Purpose: This study sought to investigate the predictive factors for atrial fibrillation (AF) recurrence in patients after radiofrequency ablation (RFCA) and construct a nomogram prediction model for providing precious information of ablative strategies. Methods: A total of 221 patients with AF who underwent RFCA were enrolled. Univariate and multivariate Cox regression were used to screen the predictors of recurrence. The receiver operating characteristic (ROC) curve and the Kaplan-Meier (K-M) curve were drawn to analyze the value of predictors. The nomogram model was further constructed to predict the recurrence of AF in patients after RFCA. Results: There were 59 cases of AF recurrence after RFCA. Monocyte count/high-density lipoprotein cholesterol (MHR), AF course (COURSE), coronary heart disease (CHD), and AF type (TYPE) were the independent risk factors for predicting AF recurrence after RFCA. Accordingly, a nomogram prediction model based on MHR, COURSE, CHD, and TYPE was constructed with a C-index of 0.818 (95% CI: 0.681∼0.954), while the C-index of verification was 0.802 (95% CI: 0.658∼0.946). Conclusions: Preoperative MHR, COURSE, CHD, and TYPE were independent risk factors for predicting recurrence of AF after RFCA. The nomogram model based on MHR, COURSE, CHD, and TYPE can be used to predict the recurrence of AF after RFCA accurately and individually.

Tenofovir Alafenamide to Prevent Perinatal Hepatitis B Transmission: A Multicenter, Prospective, Observational Study.

BACKGROUND: Few safety and effectiveness results have been published regarding the administration of tenofovir alafenamide fumarate (TAF) during pregnancy for the prevention of mother-to-child transmission (MTCT) of hepatitis B virus (HBV). METHODS: In this multicenter prospective observational study, pregnant women with HBV DNA levels higher than 200 000 IU/mL who received TAF or tenofovir disoproxil fumarate (TDF) from gestational weeks 24-35 to delivery were 1:1 enrolled and followed until postpartum month 6. Infants received immunoprophylaxis. The primary endpoint was the safety of mothers and infants. The secondary endpoint was the hepatitis B surface antigen (HBsAg)-positive rate at 7 months for infants. RESULTS: In total, 116 and 116 mothers were enrolled, and 117 and 116 infants were born, in the TAF and TDF groups, respectively. TAF was well tolerated during a mean treatment duration of 11.0 weeks. The most common maternal adverse event was nausea (19.0%). One (0.9%), 3 (2.6%), and 9 (7.8%) mothers had abnormal alanine aminotransferase levels at delivery and at postpartum months 3 and 6, respectively. The TDF group had safety profiles that were comparable to those of the TAF group. No infants had birth defects in either group. The infants' physical and neurological development at birth and at 7 months in the TAF group were comparable with those in the TDF group. The HBsAg positive rate was 0% at 7 months in all 233 infants. CONCLUSIONS: Antiviral prophylaxis with TAF was determined to be generally safe for both mothers and infants and reduced the MTCT rate to 0%.

Circulating tumor cells exit circulation while maintaining multicellularity, augmenting metastatic potential.

Metastasis accounts for the majority of all cancer deaths, yet the process remains poorly understood. A pivotal step in the metastasis process is the exiting of tumor cells from the circulation, a process known as extravasation. However, it is unclear how tumor cells extravasate and whether multicellular clusters of tumor cells possess the ability to exit as a whole or must first disassociate. In this study, we use in vivo zebrafish and mouse models to elucidate the mechanism tumor cells use to extravasate. We found that circulating tumor cells exit the circulation using the recently identified extravasation mechanism, angiopellosis, and do so as both clusters and individual cells. We further show that when melanoma and cervical cancer cells utilize this extravasation method to exit as clusters, they exhibit an increased ability to form tumors at distant sites through the expression of unique genetic profiles. Collectively, we present a new model for tumor cell extravasation of both individual and multicellular circulating tumor cells.This article has an associated First Person interview with the first author of the paper.

Production and characterization of surfactin-like biosurfactant produced by novel strain Bacillus nealsonii S2MT and it's potential for oil contaminated soil remediation.

BACKGROUND: Biosurfactants, being highly biodegradable, ecofriendly and multifunctional compounds have wide applications in various industrial sectors including environmental bioremediation. Surfactin, a member of lipopeptide family, which is considered as one of the most powerful biosurfactants due to its excellent emulsifying activities as well as environmental and therapeutic applications. Therefore, the aim of this study was to investigate the newly isolated bacterial strain S2MT for production of surfactin-like biosurfactants and their potential applications for oil-contaminated soil remediation. RESULTS: In this study, the strain S2MT was isolated from lake sediment and was identified as Bacillus nealsonii based on transmitted electron microscopy (TEM) and 16S rRNA ribo-typing. The strain S2MT produced biosurfactant that reduced the surface tension (34.15 ± 0.6 mN/m) and displayed excellent emulsifying potential for kerosene (55 ± 0.3%). Additionally, the maximum biosurfactant product yield of 1300 mg/L was achieved when the composition of the culture medium was optimized through response surface methodology (RSM). Results showed that 2% glycerol and 0.1% NH4NO3 were the best carbon/nitrogen substrates for biosurfactant production. The parameters such as temperature (30 °C), pH (8), agitation (100 rpm), NH4NO3 (0.1%) and NaCl (0.5%) displayed most significant contribution towards surface tension reduction that resulted in enhanced biosurfactant yield. Moreover, the extracted biosurfactants were found to be highly stable at environmental factors such as salinity, pH and temperature variations. The biosurfactants were characterized as cyclic lipopeptides relating to surfactin-like isoforms (C13-C15) using thin-layer chromatography (TLC), Ultra high performance liquid chromatography and mass spectrometry (UHPLC-MS). The crude biosurfactant product displayed up to 43.6 ± 0.08% and 46.7 ± 0.01% remediation of heavy engine-oil contaminated soil at 10 and 40 mg/L concentrations, respectively. CONCLUSION: Present study expands the paradigm of surfactin-like biosurfactants produced by novel isolate Bacillus nealsonii S2MT for achieving efficient and environmentally acceptable soil remediation as compared to synthetic surfactants.

Antibody-Armed Platelets for the Regenerative Targeting of Endogenous Stem Cells.

Stem cell therapies have shown promise in treating acute and chronic ischemic heart disease. However, current therapies are limited by the low retention and poor integration of injected cells in the injured tissue. Taking advantage of the natural infarct-homing ability of platelets, we engineered CD34 antibody-linked platelets (P-CD34) to capture circulating CD34-positive endogenous stem cells and direct them to the injured heart. In vitro, P-CD34 could bind to damaged aortas and capture endogenous stem cells in whole blood. In a mouse model of acute myocardial infarction, P-CD34 accumulated in the injured heart after intravenous administration, leading to a concentration of endogenous CD34 stem cells in the injured heart for effective heart repair. This represents a new technology for endogenous stem cell therapy.

Platelet-Inspired Nanocells for Targeted Heart Repair After Ischemia/Reperfusion Injury.

Cardiovascular disease is the leading cause of mortality worldwide. While reperfusion therapy is vital for patient survival post-heart attack, it also causes further tissue injury, known as myocardial ischemia/reperfusion (I/R) injury in clinical practice. Exploring ways to attenuate I/R injury is of clinical interest for improving post-ischemic recovery. A platelet-inspired nanocell (PINC) that incorporates both prostaglandin E2 (PGE2)-modified platelet membrane and cardiac stromal cell-secreted factors to target the heart after I/R injury is introduced. By taking advantage of the natural infarct-homing ability of platelet membrane and the overexpression of PGE2 receptors (EPs) in the pathological cardiac microenvironment after I/R injury, the PINCs can achieve targeted delivery of therapeutic payload to the injured heart. Furthermore, a synergistic treatment efficacy can be achieved by PINC, which combines the paracrine mechanism of cell therapy with the PGE2/EP receptor signaling that is involved in the repair and regeneration of multiple tissues. In a mouse model of myocardial I/R injury, intravenous injection of PINCs results in augmented cardiac function and mitigated heart remodeling, which is accompanied by the increase in cycling cardiomyocytes, activation of endogenous stem/progenitor cells, and promotion of angiogenesis. This approach represents a promising therapeutic delivery platform for treating I/R injury.

Therapeutic benefits of CD90-negative cardiac stromal cells in rats with a 30-day chronic infarct.

Cardiac stromal cells (CSCs) can be derived from explant cultures, and a subgroup of these cells is viewed as cardiac mesenchymal stem cells due to their expression of CD90. Here, we sought to determine the therapeutic potential of CD90-positive and CD90-negative CSCs in a rat model of chronic myocardial infarction. We obtain CD90-positive and CD90-negative fractions of CSCs from rat myocardial tissue explant cultures by magnetically activated cell sorting. In vitro, CD90-negative CSCs outperform CD90-positive CSCs in tube formation and cardiomyocyte functional assays. In rats with a 30-day infarct, injection of CD90-negative CSCs augments cardiac function in the infarct in a way superior to that from CD90-positive CSCs and unsorted CSCs. Histological analysis revealed that CD90-negative CSCs increase vascularization in the infarct. Our results suggest that CD90-negative CSCs could be a development candidate as a new cell therapy product for chronic myocardial infarction.

Generic ledipasvir-sofosbuvir for patients with chronic hepatitis C: A real-life observational study.

BACKGROUND & AIMS: Few patients from developing countries can afford brand name direct-acting antiviral agents for treating hepatitis C virus (HCV) infection, and controversy regarding the bioequivalence of generics exists. This study aimed to observe the safety and efficacy of 8 or 12weeks of generic ledipasvir-sofosbuvir with or without ribavirin for Chinese genotype 1b HCV-infected patients. METHODS: In this open-labelled observational study, 63 cirrhotic (group 1) and 65 non-cirrhotic (group 2) patients were administered generic ledipasvir-sofosbuvir plus 1000-1200mg of ribavirin daily for 12 and 8weeks, respectively; and 64 non-cirrhotic patients (group 3) received ledipasvir-sofosbuvir for 8weeks. The primary efficacy endpoint was undetectable HCV RNA at week 12 (SVR12) after cessation of therapy. Safety and pharmacokinetic data were collected. RESULTS: One hundred and eighty-seven patients completed treatment, and the latest undetectable HCV RNA was observed in three patients with cirrhosis at week 5 during treatment. Intention-to-treat analysis revealed 96.8% (61/63), 96.9% (63/65), and 96.9% (62/64) of SVR12 rates in groups 1, 2, and 3, respectively. One patient in group 3 relapsed at post-treatment week 4. The regimens were generally well-tolerated. The most common adverse events were fatigue (17.8%), diarrhea (10.9%), and headache (9.9%). Four patients discontinued therapy due to diarrhea and vomiting. One patient from group 2 discontinued treatment on day 29 because of drug-unaffordability; fortunately, she achieved SVR12. CONCLUSION: This study demonstrated that 8 or 12weeks of generic ledipasvir-sofosbuvir with or without ribavirin are safe and effective for patients with genotype 1b HCV infection. LAY SUMMARY: The price of Harvoni® has led to restrictions and access limitations in many developing and even developed countries with limited healthcare budgets. Gilead approved generic ledipasvir-sofosbuvir costs far less than Harvoni® and presents a similar cure rate for patients with chronic hepatitis C.

[Sodium nitrite enhanced the potentials of migration and invasion of human hepatocellular carcinoma SMMC-7721 cells through induction of mitophagy].

Nitrites play multiple characteristic functions in invasion and metastasis of hepatic cancer cells, but the exact mechanism is not yet known. Cancer cells can maintain the malignant characteristics via clearance of excess mitochondria by mitophagy. The purpose of this article was to determine the roles of nitrite, reactive oxygen species (ROS) and hypoxia inducing factor 1 alpha (HIF-1 α) in mitophagy of hepatic cancer cells. After exposure of human hepatocellular carcinoma SMMC-7721 cells to a serial concentrations of sodium nitrite for 24 h under normal oxygen, the maximal cell vitality was increased by 16 mg x (-1) sodium nitrite. In addition, the potentials of migration and invasion for SMMC-7721 cells were increased significantly at the same time. Furthermore, sodium nitrite exposure displayed an increase of stress fibers, lamellipodum and perinuclear mitochondrial distribution by cell staining with Actin-Tracker Green and Mito-Tracker Red, which was reversed by N-acetylcysteine (NAC, a reactive oxygen scavenger). DCFH-DA staining with fluorescent microscopy showed that the intracellular level of ROS concentration was increased by the sodium nitrite treatment. LC3 immunostaining and Western blot results showed that sodium nitrite enhanced cell autophagy flux. Under the transmission electron microscopy (TEM), more autolysosomes formed after sodium nitrite treatment and NAC could prevent autophagosome degradation. RT-PCR results indicated that the expression levels of COX I and COXIV mRNA were decreased significantly after sodium nitrite treatment. Meanwhile, laser scanning confocal microscopy showed that sodium nitrite significantly reduced mitochondrial mass detected by Mito-Tracker Green staining. The expression levels of HIF-1α, Beclin-1 and Bnip3 (mitophagy marker molecular) increased remarkably after sodium nitrite treatment, which were reversed by NAC. Our results demonstrated that sodium nitrite (16 mg x L(-1)) increased the potentials of invasion and migration of hepatic cancer SMMC-7721 cells through induction of ROS and HIF-1α mediated mitophagy.

[Exposure of human hepatoma cells to nitrite and ammonia promotes invasive activity through activation of ROS/ODC pathway].

Recent studies have demonstrated that nitrite and ammonia levels are higher in the tumor environment, but their effects on cancer cells remains unclear. The present study was designed to determine the effects of nitrite and ammonia on tumor invasion and the role of reactive oxygen (ROS)/ornithine decarboxylase (ODC) pathway. SMMC-7721 cells were treated with sodium nitrite, ammonium chloride, sodium nitrite and ammonium chloride mixture for 24 h, the cell viability was analyzed using the MTT assay, cell invasion was analyzed with the transwell assay, the intracellular ROS levels were detected with a reactive oxygen species (ROS) test kits, the expression of intracellular ODC was examined with immunofluorescence and Western blot, the expression of matrix metallopeptidase-2 (MMP-2) and MMP-9 were analyzed by Western blot. Compared with the control group, SMMC-7721 cells exhibited an increase in cell viability, invasion ability, ROS levels and ODC protein after exposure to 150 µmol·L(-1) sodium nitrite and ammonium chloride mixture for 24 h. The invasive activity was reduced by ROS scavenger N-acetycysteine (NAC) in SMMC-7721 cells. The specific ODC inhibitor difluoromethylornithine (DFMO) increased ROS levels and weakened the ability of sodium nitrite and ammonium chloride mixture in the regulation of invasion of SMMC-7721 cells. These data demonstrated that sodium nitrite and ammonium chloride mixture promote invasion of SMMC-7721 cells by enhancing ROS/ODC pathway.

The ERF transcription factor TaERF3 promotes tolerance to salt and drought stresses in wheat.

Salinity and drought are major limiting factors of wheat (Triticum aestivum) productivity worldwide. Here, we report the function of a wheat ERF transcription factor TaERF3 in salt and drought responses and the underlying mechanism of TaERF3 function. Upon treatment with 250 mM NaCl or 20% polyethylene glycol (PEG), transcript levels of TaERF3 were rapidly induced in wheat. Using wheat cultivar Yangmai 12 as the transformation recipient, four TaERF3-overexpressing transgenic lines were generated and functionally characterized. The seedlings of the TaERF3-overexpressing transgenic lines exhibited significantly enhanced tolerance to both salt and drought stresses as compared to untransformed wheat. In the leaves of TaERF3-overexpressing lines, accumulation levels of both proline and chlorophyll were significantly increased, whereas H2O2 content and stomatal conductance were significantly reduced. Conversely, TaERF3-silencing wheat plants that were generated through virus-induced gene silencing method displayed more sensitivity to salt and drought stresses compared with the control plants. Real-time quantitative RT-PCR analyses showed that transcript levels of ten stress-related genes were increased in TaERF3-overexpressing lines, but compromised in TaERF3-silencing wheat plants. Electrophoretic mobility shift assays showed that the TaERF3 protein could interact with the GCC-box cis-element present in the promoters of seven TaERF3-activated stress-related genes. These results indicate that TaERF3 positively regulates wheat adaptation responses to salt and drought stresses through the activation of stress-related genes and that TaERF3 is an attractive engineering target in applied efforts to improve abiotic stress tolerances in wheat and other cereals.

Serum soluble mesothelin-related peptide (SMRP): a potential diagnostic and monitoring marker for epithelial ovarian cancer.

PURPOSE: To explore the potential and diagnostic performance of soluble mesothelin-related peptide (SMRP) as a tumor marker for epithelial ovarian cancer (EOC). METHODS: Sera were obtained from 78 EOC patients, 84 benign ovarian tumor patients, 58 healthy volunteers, and 22/78 EOC patients 1 week after surgery. SMRP levels and diagnostic performance were assessed by ELISA using the MESOMARK kit. The combination of SMRP and CA125 in the diagnosis of EOC was assessed. RESULTS: SMRP concentrations were higher in EOC patients than in benign tumor patients and healthy volunteers, and SMRP levels were shown to decrease in EOC patients after surgery. Histological EOC subtypes showed significant differences in SMRP levels. Stage III-IV patients had a higher level of SMRP than stage I-II patients (P < 0.001). Elevated SMRP levels were also found in higher grade tumors (P < 0.001). The receiver operating characteristic curve for SMRP was 0.891. The best statistical cut-off for SMRP was 1.3109 nM, with 0.821 sensitivity and 0.979 specificity. When compared with CA125, SMRP performed better in specificity, omission diagnostic rate, positive predictive value, and correction rate, but worse for sensitivity and negative predictive value. The combination of SMRP and CA125 gave a sensitivity of 98.4 % and a specificity of 88.9 %. CONCLUSION: Serum SMRP is a promising marker for the diagnosis and monitoring of EOC, especially in combination with CA125.

Exploring plastic biofilm formation and Escherichia coli colonisation in marine environments.

Microorganisms, including potential pathogens, can colonise plastic surfaces in aquatic environments. This study investigates the colonisation of plastic pellets by Escherichia coli (E. coli) as a proxy for faecal pathogens in aquatic environments. Plastic pellets from a polluted beach were placed in seawater aquaria spiked with E. coli. Diverse bacteria, primarily from the Proteobacteria phylum, rapidly colonised the pellets within 24 h, with notable species known for plastic or hydrocarbon degradation. Over 26 days, biofilms formed on the plastic surfaces, reaching bacterial populations of up to 6.8·105 gene copies (gc) of the 16S rRNA mm-2. E. coli, was detected in the pellets for up to 7 days using culture methods, exhibiting varying attachment densities regardless of source or environmental factors. The study highlights plastic biofilms as reservoirs for E. coli, contributing to the survival and persistence of faecal bacteria in aquatic systems. These findings deepen our understanding of the risks associated with plastic pollution in marine settings, offering insights into the behaviour of faecal indicators and their implications for water quality assessments, while providing valuable information on potential pathogen dissemination within plastic-associated microbial communities.

OH* Chemiluminescence Characteristics of the RP-3 Fueled Dual-Swirl Direct-Mixing Combustor.

The flame structure characteristics of the RP-3 fueled dual-swirl direct-mixing combustor are studied experimentally. The flame shape is marked by the OH* radical, which is captured by a CMOS camera with an image intensifier. The flow fields and spray distributions are obtained by particle image velocimetry. The variation of pilot/main-stage flame structure with global fuel-air ratio (FAR), fuel ratio (FR), pilot/main-stage swirl numbers (Sp and Sm), and Δp/p (total pressure loss coefficient) is further investigated. The typical flame structure, consisting of two main-stage combustion zones (pilot-stage and main-stage combustion zones), is first analyzed. Then, according to the relationship between integral OH* intensity and global heat release rate, increasing swirl number will weaken the effect of strain rate on OH* chemiluminescence. The global FAR has little impact on the flame structure, while modifying the FR will alter the flame mode. The influence of the Sp on the flame structure is more significant than that of the Sm. Within the range of experimental conditions, the greater the swirl number, the smaller the Δp/p is required to obtain the maximum OH* radical intensity. The addition of non-swirl flow in the main-stage swirler can improve the stability of the pilot-stage flame. The equivalent swirl number is further evaluated by the neural network.

Detection of faecal bacteria and antibiotic resistance genes in biofilms attached to plastics from human-impacted coastal areas.

Plastics have been proposed as vectors of bacteria as they act as a substrate for biofilms. In this study, we evaluated the abundance of faecal and marine bacteria and antibiotic resistance genes (ARGs) from biofilms adhered to marine plastics. Floating plastics and plastics from sediments were collected in coastal areas impacted by human faecal pollution in the northwestern Mediterranean Sea. Culture and/or molecular methods were used to quantify faecal indicators (E. coli, Enterococci and crAssphage), and the ARGs sulI, tetW and blaTEM and the 16S rRNA were detected by qPCR assays. Pseudomonas and Vibrio species and heterotrophic marine bacteria were also analysed via culture-based methods. Results showed that, plastic particles covered by bacterial biofilms, primarily consisted of marine bacteria including Vibrio spp. Some floating plastics had a low concentration of viable E. coli and Enterococci (42% and 67% of the plastics respectively). Considering the median area of the plastics, we detected an average of 68 cfu E. coli per item, while a higher concentration of E. coli was detected on individual plastic items, when compared with 100 ml of the surrounding water. Using qPCR, we quantified higher values of faecal indicators which included inactive and dead microorganisms, detecting up to 2.6 × 102 gc mm-2. The ARGs were detected in 67-88% of the floating plastics and in 29-57% of the sediment plastics with a concentration of up to 6.7 × 102 gc mm-2. Furthermore, enrichment of these genes was observed in biofilms compared with the surrounding water. These results show that floating plastics act as a conduit for both the attachment and transport of faecal microorganisms. In contrast, low presence of faecal indicators was detected in plastic from seafloor sediments. Therefore, although in low concentrations, faecal bacteria, and potential pathogens, were identified in marine plastics, further suggesting plastics act as a reservoir of pathogens and ARGs.

Characterization of cry2-type genes of bacillus thuringiensis strains from soilisolated of sichuan basin, china.

Sichuan basin, situated in the west of China, is the fourth biggest basin in China. In order to describe a systematic study of the cry2-type genes resources from Bacillus thuringiensis strains of Sichuan basin, a total of 791 Bacillus thuringiensis strains have been screened from 2650 soil samples in different ecological regions. The method of PCR-restriction fragment length polymorphism (PCR-RFLP) was used to identify the type of cry2 genes. The results showed that 322 Bacillus thuringiensis strains harbored cry2-type genes and four different RFLP patterns were found. The combination of cry2Aa/cry2Ab genes was the most frequent (90.4%), followed by cry2Aa (6.8%) and cry2Ab alone (2.5%), and only one novel type of cry2 gene was cloned from one isolate (JF19-2). The full-length of this novel gene was obtained by the method of thermal asymmetric interlaced PCR (Tail-PCR), which was designated as cry2Ag1 (GenBank No. ACH91610) by the Bt Pesticide Crystal Protein Nomenclature Committee. In addition, the result of scanning electron microscopic (SEM) observation showed that these strains had erose, spherical, bipyramidal, and square crystal. And the results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that these strains harbored about one to three major proteins. These strains exhibited a wide range of insecticidal spectrum toxic to Aedes aegypti (Diptera) and Pieris rapae Linnaeus, 1758 (Lepidoptera). Particularly, JF19-2 contained cry2Ag gene had the highest insecticidal activity. All these researches mentioned above revealed the diversity and particularity of cry2-type gene resources from Bacillus thuringiensis strains in Sichuan basin.