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For studying the stress corrosion susceptibility of high manganese austenitic cryogenic steel HM400 in liquid ammonia medium, the slow strain rate test (SSRT) was used to investigate the stress corrosion susceptibility of high manganese austenitic cryogenic steel HM400 in four media: pure liquid ammonia (NH3), air+liquid ammonia (NH3+Air), 0.1 mg/L H2O+pure liquid ammonia (NH3+0.1 mg/L H2O) and air (Air) at room temperature. The fracture micro morphology, crack morphology, change of microstructure and mechanical properties of the samples before and after tests were characterized by scanning electron microscope (SEM), optical microscope (OM), X-ray diffractometer (XRD) and hardness tester. Results showed that strain strengthening occurred in high manganese austenitic cryogenic steel HM400 during tensile deformation. Moreover, HM400 steel possessed poor stress corrosion resistance in liquid ammonia medium, and hence it was not suitable as high parameterization and lightweight materials of liquid ammonia storage and transportation containers.

Wenzhou has improved its environmental quality because of comprehensive environmental remediation; nevertheless, the semen quality of infertile males remains unclear. This study determined whether better environmental quality improved semen quality in this region. We recorded semen quality data from 22 962 infertile males from January 2014 to November 2019 at the Center for Reproductive Health of The First Affiliated Hospital of Wenzhou Medical University (Wenzhou, China). Patients were predominantly 30–35 years old (33.1%) and workers (82.0%), with high school education or lower (77.6%); more than a half of the patients (52.6%) were Wenzhou household registration; and most patients (77.5%) had abnormal semen quality. Patients who were older than 40 years and workers, and those with Wenzhou household registration, had significantly worse semen quality (all P < 0.05). From 2014 to 2019, progressive sperm motility, total sperm motility, and semen volume showed increasing linear trends in all patients (P = 0.021, 0.030, and 0.005, respectively), yet normal sperm morphology showed a linearly decreasing trend (P = 0.046). Sensitivity analyses for subgroups yielded similar results. In conclusion, the improvement of environmental quality and better function of the accessory glands are associated with progressive sperm motility, total sperm motility, and semen volume. Normal sperm morphology is influenced by occupational exposures and personal lifestyle and does not improve with environmental quality. [ABSTRACT FROM AUTHOR]

This study analyzed the trend in semen quality of infertile male patients in Wenzhou, China, based on the data obtained from 38 905 patients during 2008–2016 in The First Affiliated Hospital of Wenzhou Medical University (Wenzhou, China). The results showed that only 24.9% of the patients had normal semen quality. For the semen quality of infertile male patients, that of the workers and 40-year-olds was significantly worse than the other occupational and age groups. For all the infertile patients, low semen volume, asthenozoospermia, and teratozoospermia accounted for 8.4%, 50.5%, and 54.1%, respectively. During 2008–2016, the annual mean percentage of fast forward motile spermatozoa, percentage of total forward motile spermatozoa, and percentage of spermatozoa with normal morphology decreased linearly with slopes of −2.11, −2.59, and −0.70, respectively. The proportion of patients with asthenozoospermia and multi-abnormal spermatozoa increased during 2008–2016 with slopes of 4.70 and 4.87, respectively, while for low semen volume, it decreased with a slope of −0.47 in the same time period. The proportion of patients with teratozoospermia increased from 2008 to 2011 and from 2011 to 2016 with slopes of 17.10 and 2.09, respectively. In general, the deteriorating trend of semen quality of infertile male patients in Wenzhou was obvious. Future efforts should be made to reveal the adverse influences on semen quality, such as occupational exposure, environmental quality, and living habits. Furthermore, more pervasive reproduction health education is necessary. [ABSTRACT FROM AUTHOR]

In yam (Dioscorea spp) species, bulbils at leaf axils are the most striking species-specific axillary structure and exhibit important ecological niches. Genetic regulation underlying bulbil growth remains largely unclear so far. Here, we characterize yam (Dioscorea alata L.) bulbil development using histological analysis, and perform full transcriptional profiling on key developmental stages together with phytohormone analyses. Using the stage-specific scoring algorithm, we have identified 3451 stage-specifically expressed genes that exhibit a tight link between major transcriptional changes and stages. Co-expressed gene clusters revealed an obvious over-representation of genes associated with cell division and expansion at the initiation stage of bulbils (T1). Transcriptional changes of hormone-related genes highly coincided with hormone levels, indicating that bulbil initiation and growth are coordinately controlled by multiple phytohormones. In particular, localized auxin is transiently required to trigger bulbil initiation, and be further depleted or exported from bulbils to promote growth by up-regulation of genes involved in auxinconjugation and efflux. The sharp increase in supply of sucrose and an enhanced trehalose-6-phophate pathway at T1 were observed, suggesting that sucrose probably functions as a key signal and promotes bulbil initiation. Analysis of the expression of transcription factors (TFs) predicated 149 TFs as stage-specifically expressed; several T1-specific TFs (from Aux/IAA, E2F, MYB, and bHLH families) have been shown to play key roles in triggering bulbil formation. Together, our work provides a crucial angle for in-depth understanding of the molecular programs underlying yam's unique bulbil development processes. Stage-specific gene sets can be queried to obtain key candidates regulating bulbil growth, serving as valuable resources for further functional research. [ABSTRACT FROM AUTHOR]