Dynamic simulation analysis of spur gear space driven system with large inertia load

The wide application of large inertia loads in space drive mechanisms is relatively rare in theoretical research. An 8-degree-of-freedom nonlinear dynamic model is established for the time-varying and nonlinear perturbation problems of a large inertia load space drive mechanism. The model is a two-stage spur gear model in which the effects of backlash and time-varying stiffness are considered. The 3D model was imported into ADAMS, and the nonlinear dynamic response of the system was studied by motion simulation. This paper sets up a large inertia experimental device to collect and process data. Comparing experimental results with Adams results, the correctness of the numerical model was verified, and the reasons for the differences between the two were explained. A comparative analysis of the load response under different inertia was performed to illustrate the importance of studying large inertia loads. The simulation results show that the output shaft has a great influence on the dynamic response. Changing the material of the gear can improve the transmission precision of the gear system. The analysis results in this paper enrich the research on the dynamic response of gear system, and provide a theoretical basis for the subsequent design of large inertia load gear system and improve vibration and noise during operation

Hepatitis B virus inhibition in mice by lentiviral vector mediated short hairpin RNA

<p>Abstract</p> <p>Background</p> <p>Chronic hepatitis B virus (HBV) infection is an important cause of cirrhosis and hepatocellular carcinoma. The major challenges for current therapies are the low efficacy of current drugs and the occurrence of drug resistant HBV mutations. RNA interference (RNAi) of virus-specific genes offers the possibility of developing a new anti-HBV therapy. Recent reports have shown that lentiviral vectors based on HIV-1 are promising gene delivery vehicles due to their ability to integrate transgenes into non-dividing cells. Herein, a lentivirus-based RNAi system was developed to drive expression and delivery of HBV-specific short hairpin RNA (shRNA) in a mouse model for HBV replication.</p> <p>Methods</p> <p>Hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) in the sera of the mice were analyzed by quantitative sandwich enzyme linked immunosorbent assay (ELISA) technique, hepatitis B core antigen (HBcAg) and HBsAg in the livers of the mice were detected by immunohistochemical assay, HBV DNA and HBV mRNA were measured by fluorogenic quantitative polymerase chain reaction (FQ-PCR) and quantitative real-time PCR respectively.</p> <p>Results</p> <p>Co-injection of HBV plasmids together with the lentivirus targeting HBV shRNA induced an RNAi response. Secreted HBsAg was reduced by 89% in mouse serum, and HBeAg was also significantly inhibited, immunohistochemical detection of HBcAg or HBsAg in the liver tissues also revealed substantial reduction. Lentiviral mediated shRNA caused a significant suppression in the levels of viral mRNA and DNA synthesis compared to the control group.</p> <p>Conclusion</p> <p>Lentivirus-based RNAi can be used to suppress HBV replication in vivo, it might become a potential therapeutic strategy for treating HBV and other viral infections.</p

Increased Risk of Cancer in relation to Gout: A Review of Three Prospective Cohort Studies with 50,358 Subjects

Gout is a common inflammatory disease characterized by acute arthritis and hyperuricemia. A number of epidemiological studies have suggested the critical role of gout in carcinogenesis. The aim of this study was to estimate the association between gout and cancer risk by meta-analysis of all relevant studies published to date. A comprehensive literature search in PubMed and Embase databases from their inception up to July 1, 2014, was performed to identify eligible studies. The strength for relationship between gout and the risk of different cancers was evaluated by calculating pooled relative risks (RRs) with 95% confidence intervals (95% CIs). All analyses were carried out by STATA 12.0 software. Gout patients were at an increased risk of cancer, particularly urological cancers, digestive system cancers, and lung cancer. No such significant association between gout and the risk of breast or brain cancers was observed. Sensitivity analysis did not materially alter the pooled results. Gout is a risk factor of cancer, particularly that of urological cancers, digestive system cancers, and lung cancer. The pooled data further support the hypothesis of a link between gout and carcinogenesis

Petal development and elaboration

Petals can be simple or elaborate, depending on whether they have complex basic structures and/or highly specialized epidermal modifications. It has been proposed that the independent origin and diversification of elaborate petals have promoted plant-animal interactions and, therefore, the evolutionary radiation of corresponding plant groups. Recent advances in floral development and evolution have greatly improved our understanding of the processes, patterns and mechanisms underlying petal elaboration. In this review, we compare the developmental processes of simple and elaborate petals, concluding that elaborate petals can be achieved through four main ways of modifications (i.e., marginal elaboration, ventral elaboration, dorsal elaboration and surface elaboration). Meanwhile, although different types of elaborate petals were made through different ways of modifications, they are all results of changes in the expression patterns of genes involved in organ polarity establishment and/or the proliferation, expansion and differentiation of cells. Deployment of existing genetic materials to a new function was also shown to be a key to the making of elaborate petals during evolution

Increased Risk of Cancer in relation to Gout: A Review of Three Prospective Cohort Studies with 50,358 Subjects

Gout is a common inflammatory disease characterized by acute arthritis and hyperuricemia. A number of epidemiological studies have suggested the critical role of gout in carcinogenesis. The aim of this study was to estimate the association between gout and cancer risk by meta-analysis of all relevant studies published to date. A comprehensive literature search in PubMed and Embase databases from their inception up to July 1, 2014, was performed to identify eligible studies. The strength for relationship between gout and the risk of different cancers was evaluated by calculating pooled relative risks (RRs) with 95% confidence intervals (95% CIs). All analyses were carried out by STATA 12.0 software. Gout patients were at an increased risk of cancer, particularly urological cancers, digestive system cancers, and lung cancer. No such significant association between gout and the risk of breast or brain cancers was observed. Sensitivity analysis did not materially alter the pooled results. Gout is a risk factor of cancer, particularly that of urological cancers, digestive system cancers, and lung cancer. The pooled data further support the hypothesis of a link between gout and carcinogenesis

Spray Cooling as a High-Efficient Thermal Management Solution: A Review

As one of the most promising thermal management solutions, spray cooling has the advantages of high heat-transfer coefficient and maintaining a low temperature of the cooling surface. By summarizing the influential factors and practical applications of spray cooling, the current challenges and bottlenecks were indicated so as to prompt its potential applications in the future. Firstly, this paper reviewed the heat-transfer mechanism of spray cooling and found that spray cooling is more advantageous for heat dissipation in high-power electronic devices by comparing it with other cooling techniques. Secondly, the latest experimental studies on spray cooling were reviewed in detail, especially the effects of spray parameters, types of working fluid, surface modification, and environmental parameters on the performance of cooling system. Afterwards, the configuration and design of the spray cooling system, as well as its applications in the actual industry (data centers, hybrid electric vehicles, and so on) were enumerated and summarized. Finally, the scientific challenges and technical bottlenecks encountered in the theoretical research and industrial application of spray cooling technology were discussed, and the direction of future efforts were reasonably speculated

Spray Cooling as a High-Efficient Thermal Management Solution: A Review

As one of the most promising thermal management solutions, spray cooling has the advantages of high heat-transfer coefficient and maintaining a low temperature of the cooling surface. By summarizing the influential factors and practical applications of spray cooling, the current challenges and bottlenecks were indicated so as to prompt its potential applications in the future. Firstly, this paper reviewed the heat-transfer mechanism of spray cooling and found that spray cooling is more advantageous for heat dissipation in high-power electronic devices by comparing it with other cooling techniques. Secondly, the latest experimental studies on spray cooling were reviewed in detail, especially the effects of spray parameters, types of working fluid, surface modification, and environmental parameters on the performance of cooling system. Afterwards, the configuration and design of the spray cooling system, as well as its applications in the actual industry (data centers, hybrid electric vehicles, and so on) were enumerated and summarized. Finally, the scientific challenges and technical bottlenecks encountered in the theoretical research and industrial application of spray cooling technology were discussed, and the direction of future efforts were reasonably speculated

Categorization and abundance of tags.

<p>About 5.0 million tags were sequenced, and clean tags and distinct tags were obtained after removal of low quality tags from each library. Some distinct tags were unambiguous tags after mapping to the reference genes, and some were unambiguous tag-mapped genes.</p