[Accumulation of Cry proteins in soil released from Bt rice after planting for multiple years]. / 多年种植Bt稻后外源蛋白在土壤中的积累.

Cry protein residue and accumulation in soil are two important components of the environmental safety assessment for the plantation of transgenic Bt crops. Several Bt rice lines with good commercial prospects have been developed in China, but it is unclear whether Cry proteins will accumulate in soils after multiple years of Bt rice cultivation. We planted the transgenic Bt rice lines cry1Ab/1Ac Minghui 63 (Huahui No. 1) and cry2A Minghui 63 for 9 years in the same field. The Cry proteins in the rhizosphere soil were estimated with enzyme linked immunosorbent assay (ELISA) at tillering stage and on the 60th day after harvest in each year. The Cry protein residues during the seedling, flowering and ripening stages were estimated in the first year (2012) and the last year (2020) of the experiment. In 2012, the concentration of Cry1Ab/1Ac in the rhizosphere soil of Huahui No. 1 was 1.25, 1.77, 1.97, 1.71 and 0.30 ng·g-1 at the seedling, tillering, flowering, ripening stages and on the 60th day after harvest, respectively. In 2020, the corresponding values were 1.30, 1.69, 2.03, 1.77, and 0.43 ng·g-1. In 2012, the concentration of Cry2A in rhizosphere soil of line cry2A Minghui 63 was 0.91, 1.52, 1.53, 1.37, and 0.12 ng·g-1 at the seedling, tillering, flowering, ripening stages and on the 60th day after harvest, respectively. The corresponding values in 2020 were 0.95, 1.43, 1.61, 1.40, and 0.15 ng·g-1. Results of multi-way ANOVA showed that the effect of year was not significant, but the effects of rice variety and growth stage were significant. Our results indicated that Cry proteins could be detected in rhizosphere soil during the growth stages of Bt rice, but would be degraded by 60 d after harvest, and that the concentrations of Cry proteins in the soil would not accumulate across multiple planting years.

Measurement of dose field distribution around mobile cone beam computed tomography (CBCT) / 中国辐射卫生

Objective To measure the peripheral dose distributions of the mobile head cone beam computed tomography (CBCT) and evaluate the impact of CBCT on the surrounding personnel and environment, and provide data support for clinical radiation protection management. Methods Combined with the structural characteristics of CBCT, AT1123 was used in the direction of 0° (counterclockwise), 45°, 90°, 135°, 180°, 225°, 270° and 315° in front of CBCT to measure the ambient dose equivalent rate of 30 cm, 80 cm and 130 cm away from the ground when the equipment was normally out of the beam, and the boundary of the temporary control area was drawn. At the same time, the dose level behind the lead screen 1 m away from the external surface of the equipment was measured and analyzed. Results The dose field around CBCT was symmetrically distributed with the dividing line of 0° and 180°, and the radiation dose level of 5.5 m in the direction of 0°, 3.5 m in the direction of 45°, 0.5 m in the direction of 90° and within 1.0 m in the direction of 180° (inside the "spoon" type) was higher than 2.5 μSv/h. The radiation dose levels of CT aperture 0° (straight forward), 45° and 315° behind the lead screen 1 m away from the equipment surface were 0.37 μSv/h, 0.22 μSv/h and 0.54 μSv/h, respectively. Conclusion The results show that the radiation dose around the mobile head cone beam CT is in a low dose level, the distribution of the dose field can provide necessary reference for the administrative and medical personnel to strengthen the radiation safety management. At the same time, it is suggested that lead screens should be set up in the clinical use of mobile CT to ensure the health and safety of the surrounding people and the environment.

In vitro release and pharmacokinetics of quercetin-loaded mixed micelles composed of Pluronic P123/Poloxamer 188 in rats / 中国药理学通报

Aim: To investigate the in vitro release behavior and pharmacokinetic characteristics of quercetinloaded mixed micelles composed of Pluronic P123/ Poloxamer 188 in rats. Methods: Polymer micelles were prepared by the thin-film hydration method. The quercetin release rate of quercetin mixed micelles was investigated by dynamic membrane dialysis technique in the physiological saline contained 1% Tween-80. The drug release curves were drawn. The results were evaluated by DD Solver. Ultra performance liquid chromatography (UPLC) method was employed to measure the plasma concentration of quercetin in rats after tail intravenous administration. The plasma concentration-time curves were drawn, and the pharmacokinetic parameters were calculated with PK Solver. Results: The entrapment efficiency (EE%) and loading efficiency (DL%) of mixed micelles was (94. 25 ± 2. 13)% and (8.61 ± 0. 18)%, respectively. The quercetin release rate of quercetin mixed micelles in the physiological saline contained 1% Tween-80 was (52.90 ± 1.08)%. The quercetin mixed micelles could be described by Higuchi model and expressed by the equation; F = 6. 735 t0.5 (Rsqr-adj = 0. 960 4, AlC = 75. 584 0). T1/2β, AUC0.4 and MRT0-inf of quercetin mixed micelles were calculated to be 1.2,1.5 and 2. 4 times of free quercetin, respectively. Conclusions: The quercetin-loaded mixed micelles have high entrapment efficiency and loading efficiency, which can improve the release behavior in vitro, prolong the time of quercetin, and significantly enhance the fraction of bioavailability of quercetin in rats.

Treatment of single one-stage posterior atlantoaxial fixation in Chiari malformation / 中华外科杂志

Objective@#To explore the effects of surgical technique of single one-stage posterior C1-2 screw rod fixation of Chiari malformation (CM) associated with occipitalization and without atlantoaxial dislocation.@*Methods@#A total of 23 patients with CM treated between January 2014 and October 2015 in Department of Neurosurgery of Chinese People′s Liberation Army General Hospital were retrospective reviewed. All of them were diagnosis with CM associated with occipitalization and without atlantoaxial dislocation, including 8 males and 15 females, aging from 11 to 57 years (mean (35.5±10.52) years). Single one-stage posterior C1-2 screw rod fixation with bone grafting fusion was performed. Operation time and intraoperative blood loss were recorded. Japanese Orthopaedic Association (JOA) scores and Odom rating were used to evaluate the clinical effects at pre- and post-operative. Regression of the cerebellar tonsillar was measured by MRI. The results were analyzed by paired samples t test.@*Results@#Twenty-three patients were implanted screws successfully, the vertebral artery injury and cerebrospinal fluid leakage were not found. The mean operation time was (172.7±19.9) minutes, the intraoperative blood loss was (153.9±49.3) ml. Compared to preoperative, the JOA score increased (13.7±1.6 vs. 11.5±1.4) and the tonsillar herniation decreased ((0.8±0.6)cm vs. (1.9±0.6) cm) in the last follow-up, there were statistical difference (t=13.386, P<0.01; t=17.995, P<0.01). The results of the postoperative Odom grading were as follows: 6 cases were perfect (26.1%), 13 cases were good (56.5%), 4 cases were moderate (17.4%) and no case was poor.No signs of instrument loosen or screw broken was noticed. 100% bony fusion rate was achieved. The follow-up time was 6 to 23 months (mean (10.5±3.2) months). One case developed internal fixator related discomfort, the symptom was relieved by internal fixator removal surgery performed 4 months after the operation when osseous fusion had already been achieved. No new neurologic symptoms were observed in other 22 patients.@*Conclusions@#The results of the study substantiates the effectiveness of single one-stage posterior fixation strategy for CM, which is associated with occipitalization and without atlantoaxial dislocation. This technique could be an alternative choice for this type of CM.

Geographical and Genetic Divergence Among Papaya ringspot virus Populations Within Hainan Province, China.

Papaya ringspot virus (PRSV) severely affects the global papaya industry. Transgenic papaya has been proven to have effective resistance to PRSV isolates from Hawaii, Thailand, Taiwan, and other countries. However, those transgenic cultivars failed to show resistance to Hainan Island isolates. Some 76 PRSV samples, representative of all traditional papaya planting areas across five cities (Wen Chang, n = 13; Cheng Mai, n = 14; Chang Jiang, n = 11; Le Dong, n = 25; and San Ya, n = 13) within Hainan Province, were investigated. Results revealed three genetic diversity groups (Hainan I, II, and III) that correlated with geographical distribution. Frequent mutations among PRSV isolates from Hainan were also observed. The high genetic divergence in PRSV isolates from Hainan is likely to be the cause of the failure of genetically modified papaya that targets sequence-specific virus.

Identification and Classification of Rhizobia by Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry.

Mass spectrometry (MS) has been widely used for specific, sensitive and rapid analysis of proteins and has shown a high potential for bacterial identification and characterization. Type strains of four species of rhizobia and Escherichia coli DH5α were employed as reference bacteria to optimize various parameters for identification and classification of species of rhizobia by matrix-assisted laser desorption/ionization time-of-flight MS (MALDI TOF MS). The parameters optimized included culture medium states (liquid or solid), bacterial growth phases, colony storage temperature and duration, and protein data processing to enhance the bacterial identification resolution, accuracy and reliability. The medium state had little effects on the mass spectra of protein profiles. A suitable sampling time was between the exponential phase and the stationary phase. Consistent protein mass spectral profiles were observed for E. coli colonies pre-grown for 14 days and rhizobia for 21 days at 4°C or 21°C. A dendrogram of 75 rhizobial strains of 4 genera was constructed based on MALDI TOF mass spectra and the topological patterns agreed well with those in the 16S rDNA phylogenetic tree. The potential of developing a mass spectral database for all rhizobia species was assessed with blind samples. The entire process from sample preparation to accurate identification and classification of species required approximately one hour.

Genome-wide analysis of potential cross-reactive endogenous allergens in rice (Oryza sativa L.).

The proteins in the food are the source of common allergic components to certain patients. Current lists of plant endogenous allergens were based on the medical/clinical reports as well as laboratory results. Plant genome sequences made it possible to predict and characterize the genome-wide of putative endogenous allergens in rice (Oryza sativa L.). In this work, we identified and characterized 122 candidate rice allergens including the 22 allergens in present databases. Conserved domain analysis also revealed 37 domains among rice allergens including one novel domain (histidine kinase-, DNA gyrase B-, and HSP90-like ATPase, PF13589) adding to the allergen protein database. Phylogenetic analysis of the allergens revealed the diversity among the Prolamin superfamily and DnaK protein family, respectively. Additionally, some allergens proteins clustered on the rice chromosome might suggest the molecular function during the evolution.

Identification of microRNAs by small RNA deep sequencing for synthetic microRNA mimics to control Spodoptera exigua.

Beet armyworm, Spodoptera exigua, is a major pest of cotton around the world. With the increase of resistance to Bacillus thuringiensis (Bt) toxin in transgenic cotton plants, there is a need to develop an alternative control approach that can be used in combination with Bt transgenic crops as part of resistance management strategies. MicroRNAs (miRNAs), a non-coding small RNA family (18-25 nt), play crucial roles in various biological processes and over-expression of miRNAs has been shown to interfere with the normal development of insects. In this study, we identified 127 conserved miRNAs in S. exigua by using small RNA deep sequencing technology. From this, we tested the effects of 11 miRNAs on larval development. We found three miRNAs, Sex-miR-10-1a, Sex-miR-4924, and Sex-miR-9, to be differentially expressed during larval stages of S. exigua. Oral feeding experiments using synthetic miRNA mimics of Sex-miR-10-1a, Sex-miR-4924, and Sex-miR-9 resulted in suppressed growth of S. exigua and mortality. Over-expression of Sex-miR-4924 caused a significant reduction in the expression level of chitinase 1 and caused abortive molting in the insects. Therefore, we demonstrated a novel approach of using miRNA mimics to control S. exigua development.

Rhizobium tibeticum sp. nov., a symbiotic bacterium isolated from Trigonella archiducis-nicolai (Sirj.) Vassilcz.

Isolated from root nodules of Trigonella archiducis-nicolai (Sirj.) Vassilcz. grown in Tibet, China, cells of the bacterial strains CCBAU 85039(T) and CCBAU 85027 were Gram-negative, aerobic, motile, non-spore-forming rods that formed colonies that were semi-translucent and opalescent on yeast extract-mannitol agar. In numerical taxonomy, SDS-PAGE analysis of whole-cell proteins and DNA-DNA hybridization, the two strains were very similar and were different from reference strains of defined Rhizobium species. In the phylogeny based on 16S rRNA gene sequences, they were most similar to Rhizobium etli CFN 42(T) (98.2 % similarity) and R. leguminosarum USDA 2370(T) (97.6 %). Sequence analyses of the housekeeping genes recA, atpD and glnII and the 16S-23S rRNA intergenic spacer, phenotypic characteristics and cellular fatty acid profiles strongly suggested that these two strains represented a novel species within Rhizobium. Cross-nodulation tests and sequencing of nifH and nodA genes showed that these two strains were symbiotic bacteria that nodulated Trigonella archiducis-nicolai, Medicago lupulina, Medicago sativa, Melilotus officinalis, Phaseolus vulgaris and Trigonella foenum-graecum. Based on the results, the novel species Rhizobium tibeticum sp. nov. is described to accommodate the two strains. The type strain is CCBAU 85039(T) (=LMG 24453(T) =CGMCC 1.7071(T)). The DNA G+C content of this strain is 59.7 mol% (T(m)).

Rhizobial resource associated with epidemic legumes in Tibet.

A total of 128 bacterial test strains originated from Astragalus, Caragana, Gueldenstaedtia, Medicago, Melilotus, Oxytropis, Trifolium, and Vicia grown in Tibet were characterized phenotypically and genomically. Based upon the consensus of grouping results, they were identified as 16 putative species. Twenty-five test strains belonging to seven putative species of Agrobacterium, Bradyrhizobium, and Rhizobium might be nonsymbiotic bacteria and the remaining 103 test strains were symbiotic bacteria belonging to Mesorhizobium, Rhizobium, and Sinorhizobium meliloti. Although no novel taxon was detected in the symbiotic bacteria, several characters including the alkaliphilic psychrotolerance revealed that the Tibetan rhizobia could be ecotypes adapted to the local conditions. The results also demonstrated that frequent lateral transfer of symbiotic genes might have happened in the Tibetan rhizobia since nodC genes similar to that of S. meliloti were found in several Rhizobium test strains and all the Mesorhizobium species had very similar nodC genes despite their genomic background. All of these findings demonstrated that the Tibetan rhizobia were an important resource for further studies on rhizobial ecology and application.

Review about structure-function relationships of anthraquinone derivatives from Radix et Rhizoma Rhei / 中国中药杂志

It review the structure-function relationship of natural anthraquinone derivatives from Radix et Rhizoma Rhei. The anthraquinone derivatives had many identical activities because they have the identical mother nucleus; but the strength of their activities were different, because they have different substitution groups. The anthraquinone derivatives shown the obvious structure-function relationship in many respects, such as antioxygenation, antibiosis, anticancer, the influence of immunity and so on.