Efficient degradation of rice straw through a novel psychrotolerant Bacillus cereus at low temperature.

BACKGROUND: Rice straw (RS) is one of the largest sources of lignocellulosic, which is an abundant raw material for biofuels and chemicals. However, the natural degradation of RS under a low temperature environment is the biggest obstacle to returning straw to the field. RESULTS: In the present study, one bacillus strain W118 was isolated. Strain W118 was identified as Bacillus cereus through morphological and physiological characterization and 16S rDNA sequencing. The optimum growth temperature and pH of strain W118 were 20 °C and 6.5, respectively. Simultaneously, it was found that the strain W118 grew well at low temperature, even at a temperature of 4 °C (OD600  = 1.40 ± 0.01). The decrease of various compositions of RS after the fermentation process at a temperature of 20 °C and 4 °C for 14 days was 27.00 ± 0.02% and 23.70 ± 0.04%, respectively. The composition of RS decreased to 50.71 ± 0.02% after being fermented at 4 °C for 25 days. The results of scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction of RS showed that the compositions of RS were significant decreased. CONCLUSION: This test suggests that the strain W118 is efficient for degrading RS at low temperature, which has great application potential for straw degradation in a low temperature area. © 2022 Society of Chemical Industry.

Substitution mapping of QTLs controlling seed dormancy using single segment substitution lines derived from multiple cultivated rice donors in seven cropping seasons.

KEY MESSAGE: A permanent advanced population containing 388 SSSLs was used for genetic analysis of seed dormancy; 25 QTLs including eight stable, six major and five new were identified. Seed dormancy (SD) is not only a complex biological phenomenon, but also a key practical problem in agricultural production closely related with pre-harvest sprouting (PHS). However, the genetic mechanisms of SD remain elusive. Here, we report the genetic dissection of SD in rice using 388 single segment substitution lines (SSSLs) derived from 16 donor parents. Continuous variation and positive correlations in seed germination percentages were observed in seven seasons. Genetic analysis revealed the narrow sense heritability in different seasons varied from 31.4 to 82.2% with an average value of 56.8%. In addition, 49 SSSLs exhibited significant difference to recipient parent HJX74 on SD in at least two seasons, and 12 of them were stably identified with putative QTLs in all of their corresponding cropping seasons. Based on substitution mapping, a total of 25 dormancy QTLs were detected on 11 chromosomes except the chromosome 5 with an interval length of 1.1 to 31.3 cM. The additive effects of these QTLs changed from -0.31 to -0.13, and the additive effect contributions ranged from 16.7 to 41.4%. Six QTLs, qSD3-2, qSD4-1, qSD7-1, qSD7-2, qSD7-3 and qSD11-2, showed large additive effect contributions (≥30%). Five QTLs, qSD3-3, qSD7-1, qSD7-4, qSD9-1 and qSD10-1, may represent novel ones. Furthermore, linkage and recombinant analysis delimited qSD7-1 to a locus 1.5 cM away from marker Oi2 and a 355-kb fragment flanked by RM1134 and Ui159, respectively. Taken together, this work conducts a comprehensive genetic dissection of SD and will provide more selections for breeding elite PHS-resistant rice varieties.

Effects of neuro-immuno-modulation on healing of wound combined with local radiation injury in rats.

PURPOSE: To investigate effects of neuro-immuno-modulation on wound healing by observing changes of cytokines and hypothalamic-pituitary-adrenal (HPA) axis hormones in acute stress reaction in rats with wound and combined local radiation injury. METHODS: Sixty female Wistar rats (weighting 200 ± 20 g) were randomly divided into normal control group, wound group and combined wound-local radiation (CWR) group (25 Gy local radiation post wound), 20 rats in each group. Contents of IL-1ß, IL-6 and IFN-γ and IL-4 in serum were measured and changes of adrenocorticotropic hormone (ACTH) and glucocorticoid (GC) in serum were analyzed by using enzyme-linked immunosorbent assay and radioimmunologic assay, respectively at different time points post wound and radiation. RESULTS: (1) The level of IFN-γ, one of the Th1 cell cytokines increased significantly at 14 d post CWR, which was markedly higher than that in control group and wound group. However, the level of IL-4, IL-1ß and IL-6, one of the Th2 cell cytokines, did not show obvious change. (2) Ratio of Th1/Th2 (IFN-γ/IL-4) in wound group and CWR group increased significantly at 7 d after wound and radiation, which suggested that Th1/Th2 balance drifted to Th1 immune response. The ratio of Th1/Th2 in wound group returned to the normal level up to 14 d after the wound and radiation, while the Th1/Th2 ratio in CWR group increased persistently and was much higher than that in control and wound groups. (3) Level of serous ACTH and GC in CWR group increased at 3 d post wound and radiation, and among them, level of GC showed statistically significant increase, which was much higher than that in control and wound groups. CONCLUSION: Level of serous neurohormone GC in rats increased significantly immediately after wound and radiation; while the level of IFN-γ showed significant increase only up to 14 d after wound and radiation, and the Th1/Th2 imbalance sustained till 28 d post wound and radiation. In order to reduce acute damage caused by CWR, organic immune system and nerve system showed up a marked regulate effects simultaneously and mutually. Nonetheless, the excessive stress induced by CWR causes disturbance of immunoregulation, which is one of the key reasons for delayed wound healing in CWR.

Simultaneous determination of the novel tyrosine kinase inhibitor meditinib and its active metabolite demethylation meditinib in monkey plasma by liquid chromatography-tandem mass spectrometry and its application to pharmacokinetic studies.

Meditinib (ME) is a novel tyrosine kinase inhibitor used as an antichronic myeloid leukemia drug. A simple, sensitive and specific LC/MS/MS method was developed and validated for the analysis of ME and its metabolite demethylation meditinib (PI) in monkey plasma using naltrexone as the internal standard. Sample preparation involved protein precipitation with methanol. The analysis was carried out on an Agilent C8 column (3.5 µm, 2.1 × 50 mm). Elution was achieved with a mobile phase gradient varying the proportion of a water solution containing 0.1% formic acid (solvent A) and a 0.1% formic acid in methanol solution (solvent B) at a flow rate of 300 µL/min. The method had a linear calibration curve over the concentration range of 2-1000 ng/mL for ME and 2-1000 ng/mL for PI. The lower limits of quantification of ME and PI were 2 and 2 ng/mL, respectively. The intra- and inter-day precision values were <15% and accuracy values were within ±10.0%. The mean recoveries of ME and PI from plasma were >85%. The assay has been successfully used for pharmacokinetic evaluation of ME and PI using the monkey as an animal model, and those data are reported for the first time.

High-quality Chlorella vulgaris biomass harvesting through chitosan and polyacrylamid2e.

Microalgal biomass is an emerging source of renewable energy and health-related compounds. However, harvesting of microalgae is a techno-economic hinder. In this research, chitosan and polyacrylamide were optimized harvesting condition for Chlorella vulgaris. Stirring at 300 rpm for 2 min is optimum for chitosan and polyacrylamide. Low-dose (10 mg/L) chitosan (flocculation efficiency (FE), 98.10 ± 1.06%) is more efficient than high-dose (25 mg/L) polyacrylamide (FE 94.57 ± 0.55%) for harvesting C. vulgaris. Chitosan resulted flocs settled more quickly than polyacrylamide, while polyacrylamide keep > 90% FE in a wider pH range (7-10) than chitosan (7-8). Chitosan and polyacrylamide both have no negative effect on biomass composition, including protein, carbohydrate, and carotenoid. C. vulgaris in flocs could successfully regrow in fresh culture media. The residual culture media was recycled with little impact on cell growth. All the results suggested that chitosan and polyacrylamide could harvest high-quality microalgal biomass.

Camrelizumab plus famitinib for advanced or metastatic urothelial carcinoma after platinum-based therapy: data from a multicohort phase 2 study.

BACKGROUND: Dual blockade of immune checkpoint and angiogenesis is an effective strategy for multiple cancers. Camrelizumab is a monoclonal antibody against PD-1, and famitinib is a multitargeted receptor tyrosine kinase inhibitor with antiangiogenesis and antiproliferation activities against tumor cells. We conducted an open-label, multicenter phase 2 basket study of camrelizumab and famitinib in eight cohorts of genitourinary or gynecological cancers. Here, findings in cohort of advanced or metastatic urothelial carcinoma with platinum-progressive disease (cohort 2) are presented. METHODS: Patients who had progressed after platinum-based chemotherapy for advanced or metastatic disease or had progressed within 12 months after completion of platinum-based (neo)adjuvant therapy were given camrelizumab (200 mg intravenously every 3 weeks) plus famitinib (20 mg orally once daily). Primary endpoint was objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors version 1.1. RESULTS: Totally, 36 patients were recruited. With a median duration from enrollment to data cut-off of 11.9 months (range 6.1-28.5), ORR was 30.6% (95% CI 16.3% to 48.1%). Median duration of response (DoR) was 6.3 months (95% CI 2.1 to not reached). Median progression-free survival (PFS) was 4.1 months (95% CI 2.2 to 8.2), and median overall survival (OS) was 12.9 months (95% CI 8.8 to not reached). Patients with bladder cancer (n=18) had numerically better outcomes, with an ORR of 38.9% (95% CI 17.3% to 64.3%) and a median PFS of 8.3 months (95% CI 4.1 to not reached). Median DoR and OS in this subpopulation had not been reached with lower limit of 95% CI of 4.2 months for DoR and 11.3 months for OS, respectively. Of 36 patients, 22 (61.1%) had grade 3 or 4 treatment-related adverse events, mainly decreased platelet count and hypertension. CONCLUSIONS: Camrelizumab plus famitinib showed potent antitumor activity in advanced or metastatic urothelial carcinoma patients after platinum-based chemotherapy. Patients with bladder cancer seemed to have better response to this combination. TRIAL REGISTRATION NUMBER: NCT03827837.

Camrelizumab plus Famitinib in Patients with Advanced or Metastatic Renal Cell Carcinoma: Data from an Open-label, Multicenter Phase II Basket Study.

PURPOSE: Blockade of immune checkpoint and angiogenesis is an effective treatment strategy for advanced or metastatic renal cell carcinoma (RCC). We report the results of camrelizumab plus famitinib in the RCC cohort of an open-label, multicenter, phase II basket study. PATIENTS AND METHODS: Eligible patients were enrolled to receive camrelizumab (200 mg i.v. every 3 weeks) and famitinib (20 mg orally once daily). Primary endpoint was objective response rate (ORR) per RECIST version 1.1. RESULTS: Totally, 38 patients were recruited, including 13 (34.2%) treatment-naïve and 25 (65.8%) previously treated patients. With a median duration from enrollment to data cutoff of 16.5 months (range, 6.1-20.4), 23 patients achieved a confirmed objective response, and ORR was 60.5% [95% confidence interval (CI), 43.4-76.0]. Responses in 18 (78.3%) responders were still ongoing, and Kaplan-Meier estimated median duration of response had not been reached yet (range, 1.0+-14.8+ months). Median progression-free survival (PFS) was 14.6 months (95% CI, 6.2-not reached). ORR was 84.6% (95% CI, 54.6-98.1) in treatment-naïve patients and 48.0% (95% CI, 27.8-68.7) in pretreated patients; median PFS had not been reached and was 13.4 months (95% CI, 4.1-not reached), respectively. Most common grade 3 or 4 treatment-related adverse events included proteinuria (18.4%), hypertension (18.4%), decreased neutrophil count (13.2%), palmar-plantar erythrodysesthesia syndrome (10.5%), and hypertriglyceridemia (10.5%). No treatment-related deaths occurred, and no new safety signals were observed. CONCLUSIONS: Camrelizumab plus famitinib showed potent and enduring antitumor activity in patients with advanced or metastatic RCC, both in treatment-naïve and previously treated population.

EsTrx-2, the mitochondrial thioredoxin from Antarctic microcrustacean (Euphausia superba): Cloning and functional characterization.

Thioredoxin system plays an important role in antioxidative stress, thioredoxin 2 (Trx2) being one of the most important components in the thioredoxin system. The full-length cDNA sequence of thioredoxin 2 from Euphausia superba (EsTrx2) is 1276 bp and contain a 5' untranslated region (UTR) of 94 bp, a 3' UTR of 741 bp and an open reading frame (ORF) of 441 bp, encoding a putative protein of 146 amino acids. Multiple sequence alignments have indicated that EsTrx2 possesses a conserved (-Cys-Gly-Pro-Cys-) CGPC redox-active site. EsTrx2 shares 62.3% identity with the swimming crab (Portunus trituberculatus) Trx2. The predicted three-dimensional structure of EsTrx2 consists of a thioredoxin fold. The high similarity and phylogenetic analysis have indicated that EsTrx2 is a member of the mitochondrial Trx2 sub-family. The recombinant EsTrx2 (rEsTrx2) was constructed and expressed in Escherichia coli BL21 (DE3). The rEsTrx2 protein showed high redox activity and antioxidant capacity at temperature from 4 to 37 °C. All results indicated that EsTrx2 was involved in the oxidative stress response of E. superba.

Photosynthetic bacteria improved hydrogen yield of combined dark- and photo-fermentation.

Integration of dark- and photo-fermentation is a promising strategy to enhance saline wastewater treatment efficiency and biohydrogen production. In this study, dark- and photo-fermentative bacterial consortium was respectively enriched and their communities were analyzed using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Both consortia were mainly composed of hydrogen-producing strains. After the first-stage dark-fermentation, the following conditions were applied prior to the second-stage fermentation: fermentative broth pH regulation (the pH group), glucose addition (the glucose group), glucose addition and pH regulation (the glucose + pH group), photosynthetic bacteria addition (the photo group), and photosynthetic bacteria addition and pH regulation (the photo + pH group), respectively. Dark fermentative broth with no pretreatment was used as control (the control group). Then the second stage began. The results showed that pH restriction had more influence than substrate or products restriction on dark-fermentative hydrogen production. Addition of photo-fermentative bacteria after dark-fermentation increased the hydrogen yield (134%) and substrate utilization (67%). These findings indicated syntrophic interactions between dark- and photo-fermentative bacteria during the hydrogen production process.

Photo-biological hydrogen production by an acid tolerant mutant of Rhodovulum sulfidophilum P5 generated by transposon mutagenesis.

Most of the photosynthetic bacterial strains exhibit optimum hydrogen production at neutral initial pH, and lower initial pH resulted in a sharp decrease in hydrogen yield. Thus, screening of acid-tolerant hydrogen-producing photosynthetic bacteria is very important. To obtain acid tolerant mutants, a Tn7-based transposon was randomly inserted into the genomic DNA of Rhodovulum sulfidophilum P5. An acid tolerant mutant strain TH-102 exhibited increased hydrogen production in acidic environment (pH 4.5-6.5) and at higher temperatures (35 and 37°C) than the wild-type strain. At pH 5.5 and 35°C, the mutant strain TH-102 continuously produced hydrogen. The hydrogen yield and average rate were 2.16 ± 0.10 mol/mol acetate and 10.06 ± 0.47 mL/Lh, which was about 17.32 and 15.37-fold higher than that of the wild-type strain, respectively. This acid- and temperature-tolerant mutant strain TH-102 could be used in a cost-effective hydrogen production process employing both dark fermentative and photosynthetic bacteria.

Screening and hydrogen-producing characters of a highly efficient H2-producing mutant of Rhodovulum sulfidophilum P5.

In this study, transposon mutagenesis technology was utilized to enhance the hydrogen production capability of a wild marine photosynthetic bacterium Rhodovulum sulfidophilum P5. A mutant strain TH-253 that exhibited high hydrogen yield and weaker light absorption ability was screened. Under strong light conditions, the mutant produced more hydrogen than that of the WT. Under optimum light intensity (120 µmol photons/m(2)s), the mutant achieved its highest hydrogen yield (1,436 ± 44 mL H2/L, about 3.21 ± 0.10 mol H2/mol acetate), which was 40.37% higher that of the WT. In continuous operation mode, the hydrogen yield (3.59 ± 0.11 mol H2/mol acetate) and average hydrogen production rate (16.91 ± 0.46 mL H2/Lh) of the mutant were 43.40% and 45.07% higher than those of the WT, respectively. The mutant strain TH-253 may be used as an appropriate starting strain for future photosynthesis-based large scale hydrogen production.

[Kinetics and degradation efficiency of benzotriazole in water by ozonation].

Benzotriazole (BTri) is widely used in industrial processes and households as anti-icer and corrosion inhibitors. However, the removal of BTri hasn't been reported yet. The results of an experimental study are presented which provide values for the reaction rate constants between molecular ozone and BTri, and overall reaction rate constants for the degradation of BTri in the pH range of 7-8. The kinetic rate constant for BTri degradation by molecular ozone was calculated to be 20.18 L x (mol x s)(-1) according to the experimental data. The study showed that the reaction between ozone and BTri was influenced by some factors. The degradation rate of BTri increased with the increase of the solution pH value and the water temperature, but changed little in the presence of some anions, such as NO3(-), SO4(2-) and Cl(-). The hydroxyl radical inhibitor tert-Butyl alcohol affected the removal of BTri to some degree, which proved that the ozone molecule was cooperated with the hydroxyl radical to remove BTri in the oxidation process.

[Study on the epidemiology of congenital heart disease in Tibetan ethnic children aged from 4 to 18 living at different altitudes in Qinghai province].

OBJECTIVE: The epidemiological characteristics of congenital heart disease (CHD) among Tibetan children whose age ranged from 4 to 18 at different altitude were investigated in Qinghai province. METHODS: 32 578 Tibetan children living at 2535 m, 3600 m and 4200 m were surveyed with the following 3 steps: prescreened, counterchecked and diagnosed with color Doppler. The entity distribution was then analysed and the age and gender were compared respectively. RESULTS: 235 CHD cases were identified. The total morbidity was 7.21 per thousand. CHD morbidity was rising with the increase of altitude with 5.45 per thousand at 2535 m, 6.80 per thousand at 3600 m and 9.79 per thousand at 4200 m respectively. There were significant static differences between 4200 m and the others with chi2 = 7.002 (P < 0.01) to 2535 m and chi2 = 5.540 (P < 0.05) to 3600 m. However, there was no statistical difference between 2535 m altitude and 3600 m altitude. The morbidity in different age had no statistical difference at 2535 m altitude but statistically increased with the increase of age at 3600 m and 4200 m. The total ratio of 16-18 age was significantly higher than other age periods with chi2 = 10.79 (P < 0.005) to 4-7 age period and with chi2 = 5.60 (P < 0.05) to 8-12 age period. The atrial septal defect (ASD) morbidity rates in three places was 39.1% followed by ventricular septal defect (VSD) with 32.8% and patent ductus arteriosus (PDA) with 24.7%. However, the constitute of CHD was different in different altitudes that VSD with 43.5% at 2535 m, ASD with 42.8% at 3600 m and PDA with 50.8% at 4200 m which was the highest morbidity. CONCLUSION: Morbidity, constitutes and difference in gender and age were related to altitude.