Endoplasmic reticulum stress potentiates the immunosuppressive microenvironment in hepatocellular carcinoma by promoting the release of SNHG6-enriched small extracellular vesicles.

Endoplasmic reticulum (ER) stress leads to hepatocellular carcinoma (HCC) progression. Small extracellular vesicles (sEVs) play a crucial role in modulating the tumor microenvironment (TME) by influencing cellular communication and immune responses. However, it is unclear whether ER stress modulates the TME through sEVs. In the current study, we investigated the effects and underlying mechanisms of ER stress on the HCC TME. In vivo and in vitro experiments showed that overactivated ER stress was a salient attribute of the immunosuppressive HCC TME. This was caused by the ATF4-promoted release of SNHG6-carrying sEVs, which attenuated T cell-mediated immune responses. Overall, SNHG6 modulated the immunosuppressive TME and aggravated ER stress. Meanwhile, targeting SNHG6 facilitated M1-like macrophage and CD8+ T-cell infiltration and decreased the proportion of M2-like macrophages. In addition, SNHG6 knockdown enhanced anti-PD-1 immunotherapeutic efficacy. Moreover, in HCC patients, overexpression of SNHG6 was associated with a lack of response to anti-PD-1 therapy and poor prognosis, whereas low SNHG6 expression was associated with improved therapeutic efficacy and prognoses. These data indicate that a correlation exists among ER stress, sEVs, an immunosuppressive HCC TME, and immunotherapeutic efficacy. Hence, SNHG6-targeted therapy may represent an effective strategy for patients with HCC.

Immunogenicity and safety of boosting with a recombinant two-component SARS-CoV-2 vaccine: two randomized, parallel-controlled, phase 2 studies.

BACKGROUND: Recombinant protein vaccines are vital for broad protection against SARS-CoV-2 variants. This study assessed ReCOV as a booster in two Phase 2 trials. RESEARCH DESIGN AND METHODS: Study-1 involved subjects were randomized (1:1:1) to receive 20 µg ReCOV, 40 µg ReCOV, or an inactivated vaccine (COVILO®) in the United Arab Emirates. Study-2 participating individuals were randomized (1:1:1) to receive 20 µg ReCOV (pilot batch, ReCOV HA), 20 µg ReCOV (commercial batch, ReCOV TC), or 30 µg BNT162b2 (COMIRNATY®) in the Philippines. The primary immunogenicity objectives was to compare the geometric mean titer (GMT) and seroconversion rate (SCR) of neutralizing antibodies induced by one ReCOV booster dose with those of inactivated vaccine and BNT162b2, respectively, at 14 days post-booster. RESULTS: Heterologous ReCOV booster doses were safe and induced comparable immune responses to inactivated vaccines and BNT162b2 against Omicron variants and the prototype. They showed significant advantages in cross-neutralization against multiple SARS-CoV-2 variants, surpassing inactivated vaccines and BNT162b2, with good immune persistence. CONCLUSIONS: Heterologous ReCOV boosting was safe and effective, showing promise in combating COVID-19. The study highlights ReCOV's potential for enhanced protection, supported by strong cross-neutralization and immune persistence. CLINICAL TRIAL REGISTRATION: Study-1, www.clinicaltrials.gov, identifier is NCT05323435; Study-2, www.clinicaltrials.gov, identifier is NCT05084989.

Recent advances and applications in high-throughput continuous flow.

High-throughput continuous flow technology has emerged as a revolutionary approach in chemical synthesis, offering accelerated experimentation and improved efficiency. With the aid of process analytical technology and automation, this system not only enables rapid optimisation of reaction conditions at the millimole to the picomole scale, but also facilitates automated scale-up synthesis. It can even achieve the self-planning and self-synthesis of small drug molecules with artificial intelligence incorporated in the system. The versatility of the system is highlighted by its compatibility with both electrochemistry and photochemistry, and its significant applications in organic synthesis and drug discovery. This highlight summarises its recent developments and applications, emphasising its significant impact on advancing research across multiple disciplines.

Effects of flaxseed oil supplementation on metaphase II oocyte rates in IVF cycles with decreased ovarian reserve: a randomized controlled trial.

Background: This study was designed to explore the effects of flaxseed oil on the metaphase II (MII) oocyte rates in women with decreased ovarian reserve (DOR). Methods: The women with DOR were divided into a study group (n = 108, flaxseed oil treatment) and a control group (n = 110, no treatment). All patients were treated with assisted reproductive technology (ART). Subsequently, the ART stimulation cycle parameters, embryo transfer (ET) results, and clinical reproductive outcomes were recorded. The influencing factors affecting the MII oocyte rate were analyzed using univariate analysis and multivariate analysis. Results: Flaxseed oil reduced the recombinant human follicle-stimulating hormone (r-hFSH) dosage and stimulation time and increased the peak estradiol (E2) concentration in DOR women during ART treatment. The MII oocyte rate, fertilization rate, cleavage rate, high-quality embryo rate, and blastocyst formation rate were increased after flaxseed oil intervention. The embryo implantation rate of the study group was higher than that of the control group (p = 0.05). Additionally, the female age [odds ratio (OR): 0.609, 95% confidence interval (CI): 0.52-0.72, p < 0.01] was the hindering factor of MII oocyte rate, while anti-Müllerian hormone (AMH; OR: 100, 95% CI: 20.31-495, p < 0.01), peak E2 concentration (OR: 1.00, 95% CI: 1.00-1.00, p = 0.01), and the intake of flaxseed oil (OR: 2.51, 95% CI: 1.06-5.93, p = 0.04) were the promoting factors for MII oocyte rate. Conclusion: Flaxseed oil improved ovarian response and the quality of oocytes and embryos, thereby increasing the fertilization rate and high-quality embryo rate in DOR patients. The use of flaxseed oil was positively correlated with MII oocyte rate in women with DOR. Clinical trial number: https://www.chictr.org.cn/, identifier ChiCTR2300073785.

Safety and Immunogenicity of a Recombinant Two-Component SARS-CoV-2 Protein Vaccine: Randomized, Double-Blind, Placebo-Controlled Phase I and Phase II Studies.

INTRODUCTION: ReCOV is a recombinant protein vaccine that aims to induce cross-neutralization against SARS-CoV-2 variants. The phase I and phase II studies were conducted in New Zealand and the Philippines, respectively, for ReCOV primary series. METHODS: Both studies were randomized, double-blind, placebo-controlled designed among COVID-19 vaccine-naïve healthy adults who received two doses of study vaccination with a 21-day interval. In phase I, 100 younger (15-55 years) and older (56-80 years) subjects were 4:1 randomized to receive ReCOV (20 µg or 40 µg) or placebo. In the phase II study, 347 subjects (≥ 18 years) were 2:1 randomized to receive 40 µg ReCOV or placebo. Subjects that received ReCOV were followed up for 6 months after the second dosing. The safety outcomes included solicited and unsolicited AEs, SAEs, and AESIs. The immunogenicity outcomes were live-virus neutralizing antibody (NAb) against prototype, while pseudovirus NAbs against several SARS-CoV-2 variants were included in phase II as well. RESULTS: No related SAE, AESI, or AE leading to early discontinuation were reported. The AE incidences were higher in ReCOV groups than placebo group in phase I while they were similar between study groups in phase II. The majority of solicited AEs were mild or moderate with median duration of 1.0-4.0 days. The common (≥ 10%) solicited AEs in phase I were injection site reactions, headache, pyrexia, fatigue, and myalgia, and common reported (≥ 5%) ones in phase II included injection site pain, headache, and pyrexia. Robust neutralizing activities against the prototype were observed in ReCOV groups, peaking at 14 days post the second dosing: in phase I, the GMTs for 20 µg and 40 µg ReCOV groups were 1643.2 IU/mL (95% CI 1188.5, 2271.9) and 1289.2 IU/mL (95% CI 868.3, 1914.1) in younger adults, and 1122.3 IU/mL (95% CI 722.6, 1743.1) and 680.3 IU/mL (95% CI 440.2, 1051.4) in older adults, respectively, while in the ReCOV group of phase II, the GMTs for subjects with seronegative and seropositive status at baseline were 3741.0 IU/mL (95% CI 3113.4, 4495.0) and 6138.3 IU/mL (95% CI 5255.1, 7169.9), respectively. In phase II, substantial levels of pseudovirus NAbs against SARS-CoV-2 variants were demonstrated; the peak GMTs for prototype, Omicron BA.2, and BA.4/5 were 8857, 4441, and 2644, and 15,667.3, 7334.3, and 4478.8 among seronegative and seropositive subjects, respectively. The neutralization persisted till 6 months post the second dosing, with only 2.5- to 5.2-fold declines for Omicron variants. CONCLUSIONS: Two doses of 20 µg and 40 µg ReCOV are safe and immunogenic against SARS-CoV-2 prototype. The cross-neutralizing activities against Omicron variants support ReCOV advance to late-stage clinical trials. TRIAL REGISTRATION: Phase I study, clinicaltrials.gov NCT04818801; phase II study, clinicaltrials.gov NCT05084989.

Wound cosmesis problems and other postoperative problems of laparoscopic compared to open paediatric inguinal hernia repair: A meta-analysis.

A meta-analysis research was executed to appraise the wound cosmesis problems and other postoperative problems of laparoscopic compared to open paediatric inguinal hernia (IH) repair. Inclusive literature research until March 2023 was done and 869 interconnected researches were revised. The 11 picked researches enclosed 3718 paediatric inguinal hernia were in the utilised researches' starting point, 1948 of them were utilising laparoscopic IH repairs, and 1770 were utilising open IH repairs. Odds ratios (ORs) in addition to 95% confidence intervals (CIs) were utilised to appraise the wound cosmesis problems and other postoperative problems of laparoscopic compared to open paediatric IH repairs by dichotomous approaches and a fixed or random model. Laparoscopic IH repairs had significantly lower wound cosmesis problems (OR, 0.29; 95% CI, 0.16-0.52, P < .001), metachronous contralateral inguinal hernia (MCIH) (OR, 0.11; 95% CI, 0.03-0.49, P = .003), recurrence (OR, 0.34; 95% CI, 0.34-0.99, P = .04) and postoperative problems (OR, 0.35; 95% CI, 0.17-0.73, P = .005), and higher wound score (OR, 12.80; 95% CI, 10.09-15.51, P < .001) compared to open paediatric IH. Laparoscopic IH repairs had significantly lower wound cosmesis problems, MCIH, recurrence, and postoperative problems, and a higher wound score compared to open paediatric IH. However, when interacting with its values, caution must be taken since much of the research had low sample sizes.

Coupled Effect of Chloride Corrosion and Repeated Uniaxial Compressive Loading on Unsaturated Concrete.

Concrete structure performance continuously deteriorates during operation, and the performance is simultaneously affected by chloride corrosion and repeated traffic loading. Repeated-loading-induced cracks have an impact on the rate of chloride corrosion. Chloride-induced concrete corrosion also affect the stress level of the structure under loading. Therefore, the coupled effect of repeated loading and chloride corrosion on the structural performance needs to be investigated. An upgraded test device was developed for chloride corrosion testing of unsaturated concrete structures under repeated loading. Based on the experimental results, considering the influence of repeated loading on the moisture diffusion coefficient and the chloride diffusion coefficient, a chloride transport model for unsaturated concrete under the coupled effect of repeated uniaxial compressive loading and corrosion was established. The chloride concentration under coupled loading was determined by the Crank-Nicolson finite difference method and the Thomas algorithm, and then chloride transport under the coupled effect of repeated loading and corrosion was analyzed. The results showed that the stress level and the repeated loading cycles directly affect the relative volumetric water content and chloride concentration in unsaturated concrete. The effect of chloride corrosion is more severe in unsaturated concrete compared to saturated concrete.

High Retention Immobilization of Iodine in B-Bi-Zn Oxide Glass Using Bi2O3 as a Stabilizer under a N2 Atmosphere.

The immobilization of iodine waste suffers from serious iodine loss during heat treatment. Herein, we reported on the high iodine retention immobilization of simulated radioiodine-contaminated Bi0-SiO2 sorbent in B-Bi-Zn oxide glass using Bi2O3 as a stabilizer under a N2 atmosphere. The effects of the Bi2O3 content and sintering atmosphere on the iodine immobilization behaviors (iodine retention ratio, phase composition, microstructure, and chemical stability) were investigated. It was found that the decomposition of BiI3 was prevented by adding Bi2O3 and sintering in a N2 atmosphere. The iodine retention ratio in the obtained glass waste form was significantly enhanced with increasing Bi2O3 content and sintering in the N2 atmosphere due to the synergistic effect. The achieved record-high iodine retention (92.22 ± 2.6%) was much higher than that of conventional heat treatment route (18.01 ± 3.5%). The results demonstrated that iodine was effectively immobilized through the formation of stable BixOyI (Bi5O7I and BiOI). Furthermore, the obtained iodine waste form exhibited excellent compactness and chemical stability. Owing to its high iodine retention ratio, this route can be employed to effectively immobilize radioactive iodine.

Clinical Efficacy of Creatine Phosphate Sodium and/or Vitamin C in the Treatment of Children with Viral Myocarditis: A Meta-Analysis.

Background: This study performed a meta-analysis to explore the clinical efficacy of creatine phosphate sodium (CPS) and/or vitamin C for viral myocarditis (VMC) in children, to provide guidance for its clinical treatment. Methods: A literature search was performed on PubMed, Web of Science, Embase, China National Knowledge Infrastructure, and Wanfang databases to obtain published clinical randomized controlled trials (RCTs) on CPS and/or vitamin C for VMC in children, with a time span from 2013 to 2022. Relevant data was extracted and meta-analysis was performed using the statistical software Stata 16.0. Results: A total of 723 studies were retrieved and 19 studies were finally included for meta-analysis, with a total of 1,957 patients. The meta-analysis results showed that the observation group (conventional treatment + CPS and/or vitamin C) was superior to the control group (conventional treatment alone) in treatment effective rate (OR = 3.60, 95% CI (2.55, 5.07), and P < 0.001). Additionally, the observation group had lower levels of cardiac troponin-I (SMD = - 2.63, 95% CI (- 3.51, - 1.76), and P < 0.001), creatine kinase isoenzyme (SMD = -2.78, 95% CI (- 3.53, - 2.03), and P < 0.001), lactate dehydrogenase (SMD = -1.95, 95% CI (- 2.49, - 1.42), and P < 0.001), aspartate aminotransferase (SMD = -0.87, 95% CI (- 1.84, 0.09), and P = 0.076), tumor necrosis factor-α (SMD = -3.90, 95% CI (- 4.47, - 3.06), and P < 0.001), and higher superoxide dismutase levels (SMD = 2.48, 95% CI (1.64, 3.33), and P < 0.001). Except aspartate aminotransferase, there were significant differences between the two groups in the other parameters. Conclusion: CPS and/or vitamin C treatment could greatly improve the treatment, protect myocardial function, and relieve inflammatory response in children with VMC.

Effectiveness and Safety of Cystic Fibrosis Transmembrane Conductance Regulator Modulators in Children With Cystic Fibrosis: A Meta-Analysis.

Background and Aim: Cystic fibrosis (CF) is a genetic disease that is difficult to treat and caused by dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) protein. Small molecules have been used to treat the symptom caused by CFTR mutations by restoring CFTR protein function. However, the data on children with CF are scarce. This meta-analysis aimed to evaluate the effectiveness and safety of this therapy in children diagnosed with CF. Materials and Methods: Relevant studies were identified through searching medical databases before April 1, 2022. The primary outcomes of ppFEV1, lung clearance index2.5 (LCI2.5), sweat chloride concentration (SwCI), and Cystic Fibrosis Questionnaire-Revised (CFQ-R) score were pooled and analyzed. The secondary outcomes were nutritional status (weight, BMI, stature, and their z-score) and adverse events under therapy. Results: A total of twelve studies were included. Compared with the placebo group, the pooled outcome of the ppFEV1, LCI2.5, SwCI, and CFQ-R score were improved by 7.91 {[95% confidence interval (CI), 3.71-12.12], -1.00 (95% CI, -1.38 to -0.63), -35.22 (95% CI, -55.51 to -14.92), and 4.45 (95% CI, 2.31-6.59), respectively}. Compared with the placebo group, the pooled result of the change in weight was improved by 1.53 (95% CI, 0.42-2.63). All the aforementioned results were also improved in single-arm studies. No clear differences in adverse events were found between CFTR modulator therapy and the placebo group. Conclusion: CFTR modulators could improve multiaspect function in children with CF and result in comparable adverse events.

Fetal endoscopic tracheal occlusion for moderate and severe congenital diaphragmatic hernia: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Fetoscopic endoluminal tracheal occlusion (FETO) is considered to increase survival among fetuses with congenital diaphragmatic hernia (CDH). Data from high-quality trials had been lacking until the largest randomized controlled trials (the TOTAL trials) were completed. This study aimed to elucidate the efficacy and safety of FETO for increasing the survival of fetuses with moderate or severe CDH. METHODS: Relevant studies published before August 1st, 2021 were identified by searching PubMed, Cochrane Library and Web of Science. Only randomized controlled trials (RCTs) reporting patients who underwent FETO versus patients who received standard perinatal care were included in the analysis. The primary outcome was survival in the FETO and control groups. The secondary aim was to evaluate complications during pregnancy, such as premature rupture of membranes (PROM) and preterm delivery, and neonatal complications, including the need for supplemental oxygen at birth and discharge and pulmonary hypertension in the FETO and control groups. The Mantel-Haenszel random effects model was applied, and risk ratios (RRs) or odds ratios (ORs) were calculated. RESULTS: Four RCTs were eligible for inclusion. The quality of these studies was high. The pooled estimate of survival for fetuses with moderate or severe CDH was higher in the FETO group than in the control group [odds ratio (OR), 3.43; 95% confidence interval (CI), 1.12-10.48; P = 0.03] with relatively strong evidence of between-study heterogeneity (I2 = 66%). Subgroup analysis revealed that in the severe CDH group, the pooled estimates of neonatal survival were significantly higher in the FETO group than in the control group (OR, 6.57; 95% CI, 1.39-31.06; P = 0.02). However, in the moderate CDH group, the pooled results of neonatal survival were only slightly higher in the FETO group than in the control group (OR, 1.65; 95% CI, 0.93-2.91; P = 0.08) and the difference was not significant. The risks of PROM and preterm delivery were both higher in the FETO group. No significant difference was found for the need for supplemental oxygen at birth and discharge or in pulmonary hypertension between the FETO group and matched controls. A limitation is that we were unable to calculate the effect of the second intervention on prematurity, which would have been meaningful for evaluating the risk of FETO for PROM or preterm delivery. CONCLUSION: FETO increases the survival rate in fetuses with moderate and severe CDH, especially in fetuses with severe CDH. However, FETO is associated with a higher risk of PROM and preterm delivery, and the optimal time of FETO should be carefully chosen.

Rapid prediction method of α-Glycosidase inhibitory activity of Coreopsis tinctoria extract from different habitats by near infrared spectroscopy.

α-Glucosidase is one of the main enzymes causing elevated blood glucose, and Coreopsis tinctoria extract can be used as a natural inhibitor of α-Glucosidase. Therefore, a new method was proposed for predicting the inhibitory activity on α-Glucosidase of Coreopsis tinctoria extract based on near infrared spectroscopy. The absorbance of the inhibitory system was measured by ultraviolet spectroscopy, which was used to study the inhibitory activity on a-glucosidase of Coreopsis tinctoria extract. The near infrared spectra of the solid samples were collected. By selecting spectral preprocessing and optimizing spectral bands, a rapid prediction model of the inhibitory activity was established by partial least squares regression. The root mean square error of cross-validation (RMSECV), correlation coefficient (R) value and the ratio of prediction to deviation (RPD) value were used as indicators of the evaluation model. The near infrared spectrum model was established by combining the best spectral preprocessing of the continuous wavelet transform (CWT) and the best spectral band. The root mean square error of cross-validation (RMSECV) of this model was 0.815%, the correlation coefficient (R) value was 0.942, and the ratio of prediction to deviation (RPD) was 3.0. The root mean square error of prediction (RMSEP) of the model by prediction set was 0.819%, the correlation coefficient (R) value was 0.950, and the RPD was 3.2. The model shows that the fitting relationship between the predicted inhibition value and the reference inhibition value of the near infrared spectral model is good. The results showed that there was a good correlation between near infrared spectroscopy and the inhibitory activity of Coreopsis tinctoria extract. Thus, the established model was robust and effective and could be used for rapid quantification of α-Glucosidase inhibitory activity. The prediction method is simple and rapid, and can be extended to study the inhibition of other medicinal plants.

A proof of concept for neutralizing antibody-guided vaccine design against SARS-CoV-2.

Mutations and transient conformational movements of the receptor binding domain (RBD) that make neutralizing epitopes momentarily unavailable present immune escape routes for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To mitigate viral escape, we developed a cocktail of neutralizing antibodies (NAbs) targeting epitopes located on different domains of spike (S) protein. Screening of a library of monoclonal antibodies generated from peripheral blood mononuclear cells of COVID-19 convalescent patients yielded potent NAbs, targeting the N-terminal domain (NTD) and RBD domain of S, effective at nM concentrations. Remarkably, a combination of RBD-targeting NAbs and NTD-binding NAbs, FC05, enhanced the neutralization potency in cell-based assays and an animal model. Results of competitive surface plasmon resonance assays and cryo-electron microscopy (cryo-EM) structures of antigen-binding fragments bound to S unveil determinants of immunogenicity. Combinations of immunogens, identified in the NTD and RBD of S, when immunized in rabbits and macaques, elicited potent protective immune responses against SARS-CoV-2. More importantly, two immunizations of this combination of NTD and RBD immunogens provided complete protection in macaques against a SARS-CoV-2 challenge, without observable antibody-dependent enhancement of infection. These results provide a proof of concept for neutralization-based immunogen design targeting SARS-CoV-2 NTD and RBD.

Analysis of six preservatives in beverages using hydrophilic deep eutectic solvent as disperser in dispersive liquid-liquid microextraction based on the solidification of floating organic droplet.

In this work, a deep eutectic solvent (DES) composed of tetrabutylammonium bromide (TBABr) and acetic acid in a 1:2 M ratio was applied as the dispersive solvent for the dispersive liquid-liquid microextraction based on solidification of floating organic droplet (DLLME-SFO), using 1-decanol as extractant. Six preservatives (benzoic acid, BA; sorbic acid, SA; methyl paraben, MP; ethyl paraben, EP; propyl paraben PP; and butyl paraben, BP) in beverages were determined simultaneously through high-performance liquid chromatography with a diode array detector (HPLC-DAD). Under the optimal experimental condition that consists of 200 µL of disperser (TBABr: acetic acid, 1:2), 80 µL of extractant (1-decanol), 3 min of vortex time, 4.5 of pH, 2.5 g of NaCl, the proposed method showed satisfactory linearity in the range of 0.05-50.0 mg L-1, with a correlation coefficient (R2) higher than 0.9998. The limits of detection (LODs) varied from 0.02 to 0.05 mg L-1 and the limits of quantification (LOQs) varied from 0.05-0.1 mg L-1. The relative standard deviations (intra-day and inter-days) were below 5 %. The developed method was successfully applied to the determination of preservatives in beverages.

SERS-based lateral flow assay combined with machine learning for highly sensitive quantitative analysis of Escherichia coli O157:H7.

In the present study, surface-enhanced Raman scattering-based lateral flow assay (SERS-LFA) strips were applied to promptly and sensitively detect Escherichia coli O157:H7 (E. coli O157:H7) to ensure food safety. The SERS nanotags were prepared by connecting peculiar monoclonal antibody (McAb) against E. coli O157:H7 directly onto the surfaces of gold-silver core-shell nanostructures loaded with two-layer Raman reporter molecules of 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB). The Raman signal intensity at 1335 cm-1 on the test line (T line) of SERS-LFA strips was detected in the wide range of 101-109 colony-forming units/mL (CFU/mL), and regression models based on machine learning were combined to accurately and quantitatively analyze E. coli O157:H7. The limit of detection (LOD) of the extreme gradient boosting regression (XGBR) based on the Raman signal intensity of DTNB was 6.94 × 101 CFU/mL for E. coli O157:H7, which was approximately four orders of magnitude lower than that of visual limits. In addition, although E. coli O157:H7 was spiked into the food matrices including milk and beef at an ultra-low dose of 10 CFU/mL, the SERS-LFA combined with XGBR was able to successfully explore E. coli O157:H7 from the mixture that was incubated for only 2 h, in which the recoveries were mainly distributed between 86.41 and 128.25%. In summary, these results demonstrated that the SERS-LFA had a significant potential as a powerful tool for the point-of-care testing (POCT) of E. coli O157:H7 in the early food contamination stage.

Efficient removal of atrazine from aqueous solutions using magnetic Saccharomyces cerevisiae bionanomaterial.

A novel bionanomaterial comprising Saccharomyces cerevisiae (S. cerevisiae) and Fe3O4 nanoparticles encapsulated in a sodium alginate-polyvinyl alcohol (SA-PVA) matrix was synthesized for the efficient removal of atrazine from aqueous solutions. The effects of the operating parameters, nitrogen source, and glucose and Fe3+ contents on atrazine removal were investigated, and the intermediates were detected by gas chromatography-mass spectrometry (GC-MS). In addition, the synthesized Fe3O4 particles were characterized by XRD, EDX, HR-TEM, FTIR, and hysteresis loops, and the bionanomaterial was characterized by SEM. The results showed that the maximum removal efficiency of 100% was achieved at 28 °C, a pH of 7.0, and 150 rpm with an initial atrazine concentration of 2.0 mg L-1 and that the removal efficiency was still higher than 95.53% even when the initial atrazine concentration was 50 mg L-1. Biodegradation was demonstrated to be the dominant removal mechanism for atrazine because atrazine was consumed as the sole carbon source for S. cerevisiae. The results of GC-MS showed that dechlorination, dealkylation, deamination, isomerization, and mineralization occurred in the process of atrazine degradation, and thus, a new degradation pathway was proposed. These results indicated that this bionanomaterial has great potential for the bioremediation of atrazine-contaminated water.

Magnetic bionanoparticles of Penicillium sp. yz11-22N2 doped with Fe3O4 and encapsulated within PVA-SA gel beads for atrazine removal.

A novel magnetic bionanomaterial, Penicillium sp. yz11-22N2 doped with nano Fe3O4 entrapped in polyvinyl alcohol-sodium alginate gel beads (PFEPS), was successfully synthesized. The factors including nutrient substance, temperature, pH, initial concentrations of atrazine and rotational speeds were presented and discussed in detail. Results showed that the highest removal efficiency of atrazine by PFEPS was 91.2% at 8.00 mg/L atrazine. The maximum removal capacity for atrazine was 7.94 mg/g. Meanwhile, it has been found that most of atrazine were removed by metabolism and degradation of Penicillium sp. yz11-22N2, which could use atrazine as the sole source of either carbon or nitrogen. Degradation kinetics of atrazine conformed to first-order kinetics model. The intermediates indicated that the possible pathway for atrazine degradation by PFEPS mainly included hydrolysis dechlorination, dealkylation, side-chain oxidation and ring-opening.

Preparation, performances and mechanisms of magnetic Saccharomyces cerevisiae bionanocomposites for atrazine removal.

Saccharomyces cerevisiae and nanoparticles of iron oxide (Fe3O4) which were linked with chitosan (CS) through epichlorohydrin (ECH) were encapsulated in calcium alginate to prepare a novel type of bionanocomposites. Characterization results showed that the Fe3O4-ECH-CS nanoparticles were quasi-spherical with an average diameter of 30 nm to which chitosan was successfully attached through epichlorohydrin. The saturation magnetization value of the nanoparticles was 21.88 emu/g, and ferrous and ferric irons were simultaneously observed in the magnetic nanoparticles. Data of atrazine removal by yeasts showed that both inactivated and live yeasts could decrease the concentration of atrazine effectively. The inactivated yeasts achieved 20% removal rate, which indicated that adsorption by the yeasts also played a role in the removal. Removal efficiency of atrazine was maximized at 88% under 25 °C, pH of 7 and an initial atrazine concentration of 2 mg/L. When the magnetic bionanocomposite was recycled and reused twice, only 12% and 20% drop in removal efficiency was observed at the first time and the second time severally. So, atrazine could be used by the yeasts as the sole carbon source for growth and multiplication, and both adsorption and biodegradation by the bionanocomposite contributed to atrazine removal.

Distinct regulation patterns of the two prophenoloxidase activating enzymes corresponding to bacteria challenge and their compensatory over expression feature in white shrimp (Litopenaeus vannamei).

Prophenoloxidase activating enzyme 2 (PPAE2), which belongs to the second PPAE family of prawns, was isolated from white shrimp Litopenaeus vannamei. The currently identified lvPPAE2 and lvPPAE1 from our former report were taken as model candidates to analyze the relationship of the two shrimp PPAE families as well as the regulation mechanism of shrimp PPAEs. The tissue expression of lvPPAE2 was more ubiquitous than lvPPAE1. The mRNA abundance of lvPPAE2 was about 10 percent of lvPPAE1 in co-existed tissues. When challenged with Vibrio harveyi. LvPPAE2 showed a distinct transcriptional regulation pattern compared to lvPPAE1. Silence of lvPPAE2 significantly increased shrimp's susceptibility to V. harveyi, suggesting the lvPPAE2 plays essential role in shrimp host defense. A novel PPAE specific compensatory over expression feature was found in the two lvPPAEs. Single gene specific silence of lvPPAE1 and lvPPAE2 resulted in a significant difference in reduction of hemolymph PO activity. Double silence of the two lvPPAEs failed to cause a further reduction on PO activity or shrimp mortality to bacteria, despite that double silence sufficiently suppressed both of the two lvPPAEs. Our findings suggest both lvPPAEs contribute to shrimp melanization cascade and host defense against bacteria. Distinct regulation pattern corresponding to the same pathogen invasion suggests the two lvPPAEs are actually under different regulation ways. A novel PPAE specific compensatory over expression mechanism found in our study offered us a clue in understanding the robustness of shrimp innate immunity and network of crustacean proPO activating system.