Effects of endurance training with blood flow restriction on aerobic capacity,lower limb muscle strength,and sports performance:a Meta-analysis / 中国组织工程研究

OBJECTIVE:To systematically assess the effect of blood flow restriction combined with endurance training on aerobic capacity,lower limb muscle strength,and sports performance of athletes using Meta-analysis. METHODS:3210 studies were searched in CNKI,VIP,WanFang,PubMed,Embase,Web of Science,ScienceDirect,and Cochrane databases before March 2023.After screening,12 studies and 14 research reports were included.The traditional Meta-analysis and network Meta-analysis were performed by Review Manager 5.4 and Stata 14. RESULTS:Endurance training with blood flow restriction had a medium effect size on maximal oxygen uptake(standardized mean difference(SMD)=0.59,95%confidence interval(CI):0.28-0.90,P＜0.05)and no heterogeneity.The effect of continuous pressure was better than the other pressure types(P＜0.05).Compared with sports events by anaerobic energy supply,sports events by aerobic energy supply showed better effects(P＜0.05),which was set as follows:4-8 weeks of aerobic training,20-30 minutes once,3 or more sessions per week,for a total of 12 or more sessions.Secondly,endurance training with blood flow restriction showed a large effect on the lower limb muscle strength(SMD=0.99,95%CI:0.61-1.37,P＜0.05)and no heterogeneity.A subgroup analysis showed muscle endurance was the best improved(SMD=1.11;95%CI:0.37-1.85),followed by knee extension strength(SMD=1.02,95%CI:0.37-1.67)and knee flexion strength(SMD=0.87,95%CI:0.24-1.51).Finally,endurance training with blood flow restriction showed a medium effect on sports performance(SMD=0.59,95%CI:0.13-1.06,P＜0.05),and the subgroup analysis showed a medium effect on running performance(SMD=0.55,95%CI:0.05-1.06,P＜0.05)and no heterogeneity.There was only one item of soccer specific performance that was not analyzed. CONCLUSION:Endurance training combined with blood flow restriction can improve the aerobic capacity,lower limb muscle strength,and sports performance of the athletes.And there is a large effect on lower limb muscle strength and a medium effect on aerobic capacity and sports performance.A training schedule of progressive mixed-intensity aerobic endurance training under continuous pressure for no less than 4 weeks,3 sessions per week,20-30 minutes per session,for 12 or more sessions in total is easy to obtain better training results.

Yb3+:YAG silica fiber laser.

We demonstrate a compact, room-temperature, cw Yb(3+):Y(3)Al(5)O(12) silica (Yb(3+):YAG silica) fiber laser grown by the codrawing laser-heated pedestal growth technique. A slope efficiency of 76.3% was achieved from a 7 mm Yb(3+):YAG silica fiber, corresponding to an extracted power of nearly 1 W/cm. A laser side-mode suppression ratio of 70 dB was obtained with a 3 dB linewidth of 0.15 nm. Additionally, the propagation loss and emission cross section were determined by analyzing the lasing thresholds and slope efficiencies.

Survey on host animal and molecular epidemiology of hantavirus in Chuxiong prefecture, Yunnan province / 中华流行病学杂志

Objective To determine the hosts of hantavirus (HV) and its molecular epidemiological characteristics, to provide evidence for prevention and control on hemorrhagic fever with renal syndrome (HFRS). Methods Rodents were captured by a special trap within the residential area. The antigens of HV in lung tissues were detected by direct immuno-fluorescence assay (DFA). Nucleotide sequences of HV were amplified by RT-PCR with HV genotype-specific primer. The amplified genes were then sequenced. Phylogenetic tree were built on nucleotide sequence with Clusta1X 1.83 software. Results 1421 rodents were captured and classified into 8 species of 4 Genera in the epidemic area within 10 counties of Chuxiong prefecture, Yunnan province, between 2005 and 2006. Out of the 1421 rodents, 1056 (74.31%) of them were Rattus norvegicas and 280 (19.70%) belonged to Rattus flavipectus. The antigens of HV were detected by DFA in lung tissues and the total positive rate of HV was 5.15% (53/ 1029). After applying the sequencing nucleotide method to the 53 positive specimens, data showed that 21 specimens were positive and all of them belonged to Seoul type ( 15 samples were from Rattus norvegicus, 4 samples Rattasflavipectas, 2 samples Rattus nitidas). The partial S segments from 12 specimens were sequenced which appeared homologic with R22, L99 and HLD65 from GenBank in relatively high level (87.1%-99.7%). When compared to 76-118 strain of Hantaan type, their homologic degree was only 64.4%-69.1%. Results from Phylogenetic analysis showed that 12 specimens belonged to Seoul type. As for their homology, they were significantly similar to Seoul type and could be tentatively divided into two subtypes S1 and S3. Conclusion It was confirmed that the Seoul type virus, as HFRS' s pathogenetic agent mainly carried by rats, prevailed widely in Chuxiong prefecture. Owing to the local ecological environment, we also noticed the characteristics of different HV subtypes among Seoul type.

Cr(4+):YAG double-clad crystal fiber laser.

We report what we believe to be the first demonstration of a room-temperature, continuous-wave Cr(4+):Y(3)Al(5)O(12) (Cr(4+):YAG) double-clad crystal fiber laser grown by the codrawing laser heated pedestal growth method. The threshold is below 100 mW, which is a factor of 4 lower than previously reported Cr(4+)-doped lasers. A slope efficiency of 6.9% was obtained, and is in good agreement with the numerical simulation. In additional to small core diameter, the low-threshold lasing is made possible by the low propagation loss of 0.08 dB/cm and the high crystallinity of the core.