[Correlation of sperm nuclear maturity with the outcomes of in vitro fertilization].

Objective: To investigate the correlation between sperm nuclear maturity and the outcomes of in vitro fertilization (IVF). METHODS: We retrospectively analyzed the clinical data on 1 393 cycles of IVF in our center from September 2018 to May 2020. According to the high DNA stainability (HDS) of sperm, we divided the patients into a mature (HDS ≤ 10%) and an immature sperm nucleus group (HDS > 10%), compared the results of IVF, embryonic development and clinical outcomes between the two groups, and analyzed their correlation with HDS. RESULTS: The rates of fertilization and normal fertilization were significantly higher and that of fertilization failure remarkably lower in the mature than in the immature sperm nuclear group (P < 0.05). There were no statistically significant differences between the two groups in the rates of cleavage, high-quality embryo, blastocyst formation, clinical pregnancy, miscarriage and live birth (P > 0.05). Univariate logistic regression analysis showed that HDS was correlated negatively with the rates of fertilization, normal fertilization and blastocyst formation (P < 0.05), positively with fertilization failure (P < 0.05), but not significantly with the rates of cleavage, high-quality embryo, clinical pregnancy, miscarriage and live birth (P > 0.05). After adjusting for confounding factors by multivariate logistic regression analysis, HDS was found correlated negatively with the fertilization rate (OR = 0.945, 95% CI: 0.918 to 0.972, P < 0.05), positively with fertilization failure (OR = 1.043, 95% CI: 1.010 to －1.078, P < 0.05), but not significantly with the rates of normal fertilization, cleavage, high-quality embryo, blastocyst formation, clinical pregnancy, miscarriage and live birth (P > 0.05). CONCLUSIONS: Sperm nuclear maturity significantly affects the rates of fertilization and fertilization failure in IVF patients. Taking sperm nuclear maturity indicators in consideration in the process of IVF may contribute to comprehensive evaluation of semen and male fertility and guide clinical decision-making.

[Adaptive mechanism of photosynthetic apparatus of plants to light environment: State transition.] / æ¤ç‰©å ‰åˆæœºæž„å¯¹å ‰çŽ¯å¢ƒçš„é€‚åº”æœºåˆ¶: 状态转换.

Under natural conditions, light plants receive usually changes. Thus, the plants have formed corresponding adaptation mechanism in the evolutionary process, which could maintain the energy balance between two light reactions in the process of light changing. Through the movement of leaves and chloroplasts, as well as the accumulation of light-absorbing pigments, plants could regulate light absorption. Also, plants have a mechanism for greatly regulating the distribution of energy absorbed by light-harvesting complex. Especially at low light intensities, plants could mediate reversible phosphorylation of light-harvesting complex2 (LHC2) by regulating kinase and phosphatase in relation to the redox state of the electron transfer chain, which could thereby regulate the allocation of excitation energy between photosystem I (PSI) and photosystem 2(PS2). The state transitions are the quite significant mechanism of plants for adapting to the change of light environment. In this paper, the research progresses of state transitions during the change of light environment were summarized, especially the significance and functions of reversible phosphorylation and movement of LHC2 between PS I and PS2 were discussed. Finally, the future research direction on state transitions of plants was briefly proposed.

[Effects of mulberry/soybean intercropping on the plant growth and rhizosphere soil microbial number and enzyme activities].

A root separation experiment was conducted to investigate the plant growth and rhizosphere soil microbes and enzyme activities in a mulberry/soybean intercropping system. As compared with those in plastic barrier and nylon mesh barrier treatments, the plant height, leaf number, root length, root nodule number, and root/shoot ratio of mulberry and soybean in non-barrier treatment were significantly higher, and the soybean's effective nodule number was larger. The available phosphorous content in the rhizosphere soils of mulberry and soybean in no barrier and nylon mesh barrier treatments was increased by 10.3% and 11.1%, and 5.1% and 4.6%, respectively, as compared with that in plastic barrier treatment. The microbial number, microbial diversity, and enzyme activities in the rhizosphere soils of mulberry and soybean were higher in the treatments of no barrier and nylon mesh barrier than in the treatment of plastic barrier. All the results indicated that there was an obvious interspecific synergistic effect between mulberry and soybean in the mulberry/soybean intercropping system.

[Effects of Festuca arundinacea on the microbial community in crude oil-contaminated saline-alkaline soil].

By using the routine soil physical and chemical analysis methods and the Biolog technique, this paper studied the effects of Festuca arundinacea growth on the pH value, total salt content, and microbial community in the rhizosphere of crude dil-contaminated saline-alkaline soil in Songnen Plain of Northeast China. Crude oil contamination resulted in the increases of average well color development (AWCD), Shannon index (H), and carbon source utilization richness index (S), and altered the utilization patterns of carbon sources by the microbes. F. arundinacea had greater potential to remediate crude oil-contaminated soil. This plant could decrease the soil pH and soil total petroleum hydrocarbon (TPH) content, and increase the soil water content. The AWCD and S in F. arundinacea rhizosphere soil were obviously higher than those in the soil of naked land, providing a suitable environment for the growth and development of rhizosphere soil microbes.