Search

Novel graphite-molybdenum carbide nanocomposites (G-Mo2C) are synthesized by a typical solid state reaction with melamine and MoO3 as precursors under inert atmosphere. The characterization results indicate that G-Mo2C composites are composed of high crystallization and purity of Mo2C and few layers of graphite carbon. Mo2C nanoparticles with sizes ranging from 5 to 50 nm are uniformly supported by surrounding graphite layers. It is believed that Mo atom resulting from the reduction of MoO3 is beneficial to the immobilization of graphite carbon. Moreover, the electrocatalytic performances of G-Mo2C for ORR in alkaline medium are investigated by cyclic voltammetry (CV), rotating disk electrode (RDE) and chronoamperometry test with 3M methanol. The results show that G-Mo2C has a considerable catalytic activity and superior methanol tolerance performance for the oxygen reduction reaction (ORR) benefiting from the chemical interaction between the carbide nanoparticles and graphite carbon. [ABSTRACT FROM AUTHOR]

Many flooding-tolerant species are clonal plants; however, the effects of physiological integration on plant responses to flooding have received limited attention. We hypothesise that flooding can trigger changes in metabolism of carbohydrates and ROS (reactive oxygen species) in clonal plants, and that physiological integration can ameliorate the adverse effects of stress, subsequently restoring the growth of flooded ramets. In the present study, we conducted a factorial experiment combining flooding to apical ramets and stolon severing (preventing physiological integration) between apical and basal ramets of Cynodon dactylon, which is a stoloniferous perennial grass with considerable flooding tolerance. Flooding-induced responses including decreased root biomass, accumulation of soluble sugar and starch, as well as increased activity of superoxide dismutase ( SOD) and ascorbate peroxidase ( APX) in apical ramets. Physiological integration relieved growth inhibition, carbohydrate accumulation and induction of antioxidant enzyme activity in stressed ramets, as expected, without any observable cost in unstressed ramets. We speculate that relief of flooding stress in clonal plants may rely on oxidising power and electron acceptors transferred between ramets through physiological integration. [ABSTRACT FROM AUTHOR]

The coal wall, gob-side backfill, and gangues in goaf, constitute the support system for Gob-side entry retaining (GER) in coal mines. Reasonably allocating and utilizing their bearing capacities are key scientific and technical issues for the safety and economic benefits of the GER technology. At first, a mechanical model of GER was established and a governing equation for coordinated bearing of the coal-backfill-gangue support system was derived to reveal the coordinated bearing mechanism. Then, considering the bearing characteristics of the coal wall, gob-side backfill and gangues in goaf, their quantitative design methods were proposed, respectively. Next, taking the No. 2201 haulage roadway serving the No. 7 coal seam in Jiangjiawan Mine, China, as an example, the design calculations showed that the strains of both the coal wall and gobside backfill were larger than their allowable strains and the rotational angle of the lateral main roof was larger than its allowable rotational angle. Finally, flexible-rigid composite supporting technology and roof cutting technology were designed and used. In situ investigations showed that the deformation and failure of surrounding rocks were well controlled and both the coal wall and gob-side backfill remained stable. Taking the coal wall, gob-side backfill and gangues in goaf as a whole system, this research takes full consideration of their bearing properties and provides a quantitative basis for design of the support system. [ABSTRACT FROM AUTHOR]

β-SiC nanoparticles (NPs) were anchored onto the surface of reduced graphene oxide (RGO) by a facile solvothermal method. The characterization results of the novel RGO-SiC composites indicate an effective chemical interaction between the RGO sheets and β-SiC NPs. Moreover, methylene blue (MB) dye was employed as a model pollutant to evaluate the adsorption and photocatalytic ability of the composites. It is found that the content of RGO sheets can significantly tune the adsorption and photocatalytic activity of various composites with an optimal value of 3 wt%. The enhancement of photocatalytic activity can be attributed to the synergistic effect of the accelerated separation of photogenerated electron-hole pairs, and the enhanced absorption ability for dyes is mainly due to the RGO sheets which work as an excellent photocatalyst supporter and offer electrons channel to accept and transfer the photogenerated carriers from excited β-SiC NPs. [ABSTRACT FROM AUTHOR]

Giant cell tumor of bone (GCTB) is a common locally aggressive junctional primary bone tumor, whose clinical treatment becomes more difficult once combined with pathological fracture. Extended curettage and en-bloc resection are common surgical procedures for treating GCTB, and drugs such as receptor activator of nuclear factor-κB ligand(RANKL) inhibitors and bisphosphonates have been successfully used. Curettage is recommended for patients with Campanaccigrade Ⅱor Campanaccigrade Ⅲ with localized soft tissue invasion only and simple fractures with intact bone structure. Resection may be considered for Campanaccigrade Ⅲ with extensive soft tissue invasion or complex fractures with incomplete bone structure. RANKL inhibitors such as denosumab may be recommended if surgery is not possible or before performing resection. This article summarizes the common treatment modalities of pathological fractures combined with giant cell tumors of extremities, including the current status of surgical and pharmacological treatments, analyzing the choice of surgical modalities in different clinical situations, in order to provide clinical inspirations for diagnosis and treatment.

Importance: Zika virus (ZIKV) infection in pregnant women during the third trimester can cause neurodevelopmental delays and cryptorchidism in children without microcephaly. However, the consequences of congenital ZIKV infection on fertility in these children remain unclear. Here, using an immunocompetent mouse model, we reveal that congenital ZIKV infection can cause hormonal disorders of the hypothalamic-pituitary-gonadal axis, leading to reduced fertility and decreased sexual preference. Our study has for the first time linked the hypothalamus to the reproductive system and social behaviors after ZIKV infection. Although the extent to which these observations in mice translate to humans remains unclear, these findings did suggest that the reproductive health and hormone levels of ZIKV-exposed children should receive more attention to improve their living quality., Competing Interests: The authors declare no conflict of interest.

Objective: To analyze the occupational health monitoring data of workers in Zhoushan City, and provide scientific basis for health monitoring and the formulation of occupational disease prevention measures. Methods: From January 2016 to November 2019, the occupational health examination data of 37826 workers in Zhoushan City were collected to analyze the change trend of the detection rate of suspected occupational diseases and occupational contraindications, and to compare the health monitoring status of workers with different social characteristics such as enterprise scale and economic type. Results: From 2016 to 2019, the detection rate of suspected occupational diseases showed a downward trend (χ(2)(trend)=21.09, P <0.05) . The occupational health examination of on-the-job workers in Zhoushan were mainly small enterprises (59.72%, 22591/37826) , private economic enterprises (65.32%, 24707/37826) , male (82.03%, 31028/37826) , 30-49 years old (59.11%, 22359/37826) , and exposed to noise (67.06%, 25365/37826) . The detection rates of occupational contraindications and suspected occupational diseases were higher in micro enterprise, male, over 60 years old, exposed to occupational hazards for more than 49 months, and exposed to chemical and physical hazards at the same time. The detection rates of occupational contraindications and suspected occupational diseases were significantly different among different enterprise scale, economic type, gender, age and occupational hazard factors ( P <0.05) . Among benzene workers with occupational contraindications and suspected occupational diseases, the detection rate of A/G abnormality in female workers was higher than that in male workers ( P =0.04) , and there was no significant difference in other genders ( P >0.05) . Conclusion: It is necessary to pay more attention to the workers working in small and private enterprises in Zhoushan City, strengthen the occupational health supervision of male workers who are over 60 years old who are exposed to benzene, noise and other occupational hazards, standardize the occupational health inspection, and effectively protect the health of the occupational population.

Objective: To examine the short-term outcomes of modified load-sharing rip-stop repair (mLSRS) and suture-bridge repair (SB) for large rotator cuff tear. Methods: The clinical data of patients who underwent shoulder arthroscopy for large rotator cuff repair at Department of Orthopedic, China Academy of Chinese Medical Sciences Wang Jing Hospital from January 2017 to December 2018 were collected. Totally 111 patients (39 in mLSRS group and 72 in SB group) were included in the study. There were 45 males and 66 females, aged (58.0±6.9)years (range: 40 to 72 years).A total of 39 pairs of patients were successfully matched by propensity score matching. The pain of shoulder joint was assessed by visual analogy score (VAS) , the shoulder function was assessed by Constant-Murley score, the abduction strength of bilateral shoulder joint was assessed by 90˚ force assessment method of upper limb on the plane of scapula, and the healing of rotator cuff on the operative side was assessed by sugaya ultrasonic classification standard. The difference of short-term outcome between the two groups were compared using t test, χ(2) test, Mann-Whitney U test, repeated measures design anova and multivariate analysis of variance. Results: At the 4th week after surgery, the VAS of mLSRS group was significantly lower than SB group(1 (2) vs . 2 (2) , F= 5.32, P= 0.02). One year after surgery, Constant-Murley score of two groups were significantly higher than those before surgery, but there was no significant difference between two groups(89.1±5.7 vs . 87.6±7.3, t= 1.00, P= 0.32). Abductor strength of affected limbs were lower than that of the opposite side, but there were no statistically significant differences between two groups(4.28±1.61 vs . 4.54±1.64, t= -0.70, P= 0.49). According to the Sugaya classification, 32 cases in mLSRS group were healed while 7 cases were not healed,30 cases in SB group were healed while 9 cases were not healed(χ(2)=0.32, P= 0.58). Conclusion: The use of mLSRS fixation construct on large rotator cuff tear can reduce pain and the short-term outcome is reliable.

Objective: To analyze the sequences of the cytochrome C oxidase subunit I ( Cox1 ) gene of various Echinococcus granulosus genotypes that are currently recorded in the GenBank database, so as to investigate the genetic variation and differentiation of the E. granulosus genotypes across the world., Methods: The sequences of the Cox1 gene of various E. granulosus genotypes that are currently recorded in the GenBank database were collected, and the same sequences of the Cox1 gene identified from a region were excluded. The mutation sites among the Cox1 gene sequences were identified and a phylogenetic tree was created based on the Cox1 gene., Results: Transversion mutation was the predominant type of mutation in the Cox1 gene of E. granulosus . The same Cox1 gene sequence was found in E. granulosus G1, G6 and G7 genotypes isolated from various geographical locations across the world, with the corresponding GenBank accession numbers of KY766891, MH300971 and MH301007, respectively. Phylogenetic analysis revealed that E. granulosus G10 genotype had a remarkable geographical aggregation., Conclusions: E. granulosus G1, G6 and G7 genotypes have primitive Cox1 gene sequences. There is a geographical aggregation of the E. granulosus G10 genotype in the phylogenetic tree, which has a tendency towards reproductive isolation.