温度对剑尾鱼性逆转的影响

本文研究了剑尾鱼（Ｘｉｐｈｏｐｈｒｕｓｈｅｌｉｅｒｉ）在体型和性行为方面，雌鱼生殖后在不同温度下转变为雄性的现象．雌剑尾鱼在能生存的温度范围内，都有性逆转现象，但在生存温度的上限和下限内性逆转率较高，其余温度内性逆转率较低，甚至为零．

Single dose of intra-muscular platelet rich plasma reverses the increase in plasma iron levels in exercise-induced muscle damage:A pilot study

Background:Platelet rich plasma(PRP) therapy is widely used in enhancing the recovery of skeletal muscle from injury.However,the impact of intramuscular delivery of PRP on hematologic and biochemical responses has not been fully elucidated in exercise-induced muscle damage.The purpose of this investigation the effects of intramuscular delivery of PRP on hematologic and biochemical responses and recovery strategy muscle damage induced by high intensity muscle exercise(exercise-induced muscle damage,EIMD).Methods:Moderately active male volunteers participated in this study and were assigned to a control group(control,n = 6) and PRP administration group(PRP,n = 6).The subjects performed exercise with a load of 80% one repetition maximum(1RM) maximal voluntary contraction of the elbow flexors until point of exhaustion of the non-dominant arm was reached.The arms were treated with saline or autologous PRP post-24 h EIMD.Venous blood samples were obtained in the morning to establish a baseline value and 1–4 days post-exercise and were analyzed for serum ferritin,iron,iron binding capacity(IBC),creatinine kinase(CK),lactate dehydrogenase(LDH),aspartate aminotransferase(AST),and alanine aminotransferase(ALT).Results:The baseline levels of plasma iron,ferritin,IBC,CK,LDH,AST,and ALT were similar in both the control and PRP groups.However,24-h following exercise a significant increase in these parameters was observed in both groups between 1 and 4 days during the recovery period.Interestingly,PRP administration decreased plasma iron levels compared to the control on the second day post-exercise.Plasma IBC increased in PRP group from Days 2 to 4 post-exercise compared to the control group whilst PRP administration had no effect on plasma ferritin,CK,AST,ALT,or LDH.Conclusion:Acute exhaustive exercise increased muscle damage markers,including plasma iron,IBC,and ferritin levels,indicating muscle damage induced by exercise.PRP administration improves inflammation by reversing the increase in the iron levels post-exercise without displaying any myotoxicity and may have a role to play in the recovery of exercise-induced muscle damage.

Evaluation of Sensitivities and Specificities of SARS-CoV Detection by Real-time Quantitative Reverse Transcription-PCR Assays

The etiological agent of severe acute respiratory syndrome(SARS) was identified as a new coronavirus,termed SARS-CoV. Establishment of an efficient and sensitive diagnostic system of SARS-CoV genetic materials is crucial for SARS control. In this study,we quantified SARS-CoV mRNAs in both infected cell culture lysate and in supernatant by using Real-time quantitative revere transcription-PCR based on EvaGreenTM dye and Taqman-MGB probes. For extensive evaluation of sensitivities and specificities,13 pairs of primers and 4 probes were designed based on different genes of SARS-CoV. Glyceraldehydes-3-phosphate dehydrogenase(GAPDH) was selected as the internal control gene. Results showed that S-gene-specific PCR was the most sensitive for detection,but because of its sequence variability in the different viral strains,primers and a probe based on the N gene were suitable substitutions. Meanwhile,we found the mRNA concentrations in cell culture lysates were much higher than in cell supernatant and facilited more sensitive detection of the SARS-CoV.

Feasibility analysis of the angular momentum reversal trajectory via hodograph method for high performance solar sails

In this paper a new phase space of hodograph method is adopted to investigate and better understand the two-dimensional angular momentum reversal(H-reversal) trajectories for high performance solar sails within a fixed cone angle.As the hodograph method and the H-reversal trajectory are not very common,both of them are briefly introduced.The relationship between them are constructed and addressed with a sample trajectory.How the phase space varies according to the sail quality and the fixed sail cone angle is also studied.Through variation of the phase space,the minimum sail lightness number can be obtained by solving a set of algebraic equations instead of a parameter optimization problem.For a given sail lightness number,there are three types of the two-dimensional possible heliocentric motion,including the spiral inward trajectories towards the Sun,the H-reversal trajectories and the directly outward escape trajectories.The boundaries that separate these different groups are easily determined by using the phase space.Finally,the method and procedures to achieve the feasible region of the H-reversal trajectory with required perihelion distance are presented in detail.