The acclimatization to extreme environments and its physiological mechanisms

Acclimatization is a process of biological adaptation when exposed to environmental factors such as hypoxia,cold and heat for prolonged periods of time,where non-genetical variations play a role in allowing subjects to tolerate hypoxic,cold or hot environments.This review focuses on the characteristics and mechanisms of acclimatization found through major research advances by our institute.First,the mechanisms underlying the acclimatization to extreme environments are complex.In our investigations,the physiological changes of multiple systems including the nervous,circulatory,respiratory,and hemopoietic system were demonstrated when the acclimatization to hypoxia was developed,and the underlying significance of hypoxia-inducible factor-1(HIF-1) was investigated.Second,it is suggested that the development of acclimatization to extreme environments is complicated.Hypoxia and cold coexist at high altitude.Our investigations revealed the characteristics of negative cross-relationship in the acclimatization to hypoxia and cold.And third,it is interesting for us to understand that acclimatization to extreme environments is transferable among individuals,and the characteristics of heat acclimatizationinducing factor(HAIF) were presented.The above findings will provide a theoretical guidance for protective operations and help to establish a solid foundation for future research related to acclimatization.

Increased Expression of Serum Monocyte Chemoattractant Protein-1,Chemokine(C-C motif)Ligand 3,and Interleukins in Patients With Vitiligo

Objective:Vitiligo is a chronic,acquired depigmentation of the skin,which can be divided into active and stable vitiligo.The stable and active stages are not immutable and often alternate.Identification of internal markers would help to diagnose the active stage of vitiligo,and the purpose of this study was to find potential active markers in the progression of vitiligo.Methods:We compared 30 healthy controls to 60 patients with vitiligo(30 with active disease and 30 with stable disease)regarding the expression of serum monocyte chemoattractant protein(MCP)-1,chemokine(C-C motif)ligand(CCL)3,CCL5,CCL21,interleukin(IL)-6,and IL-17.Specimens were collected from May 2017 to December 2018.Serological detection was carried out by enzyme-linked immunosorbent assay.The difference between groups was compared by Kruskal-Wallis H test and Mann-Whitney U test.Results:We found that the serum levels of MCP-1,CCL3,IL-6,and IL-17 were significantly higher in patients with vitiligo than in healthy controls(P<0.01)and that IL-17 was higher in patients with active vitiligo than in those with stable vitiligo(P<0.01).After 3months of treatment,the serum IL-17 level of patients with active vitiligo was not significantly different from that before treatment(P=0.526);after 6months of treatment,however,the serum IL-17 level had significantly decreased(P<0.01).Conclusion:These findings suggest that the serum IL-17 level can be used as a marker of vitiligo disease activity giving it certain guiding significance for clinical treatment.

Effect of transient scrotal hyperthermia on sperm parameters, seminal plasma biochemical markers, and oxidative stress in men

In this experimental prospective study, we aimed to analyze the effect of transient scrotal hyperthermia on the male reproductive organs, from the perspective of sperm parameters, semen plasma biochemical markers, and oxidative stress, to evaluate whether different frequencies of heat exposure cause different degrees of damage to spermatogenesis. Two groups of volunteers （10 per group） received testicular warming in a 43~C water bath 10 times, for 30 min each time： group 1：10 consecutive days; group 2： once every 3 days. Sperm parameters, epididymis and accessory sex gland function, semen plasma oxidative stress and serum sex hormones were tested before treatment and in the 16-week recovery period after treatment. At last, we found an obvious reversible decrease in sperm concentration （P = 0.005 for Group 1 and P = 0.008 for Group 2 when the minimums were compared with baseline levels, the same below）, motility （P= 0.009 and 0.021, respectively）, the hypoosmotic swelling test score （P-- 0.007 and 0.008, respectively）, total acrosin activity （P = 0.018 and 0.009, respectively）, and an increase in the seminal plasma malondialdehyde concentration （P = 0.005 and 0.017, respectively）. The decrease of sperm concentration was greater for Group 2 than for Group 1 （P = 0.031）. We concluded that transient scrotal hyperthermia seriously, but reversibly, negatively affected the spermatogenesis, oxidative stress may be involved in this process. In addition, intermittent heat exposure more seriously suppresses the spermatogenesis compared to consecutive heat exposure. This may be indicative for clinical infertility etiology analysis and the design of contraceptive methods based on heat stress.

Comparative Transcriptional Profiling and Preliminary Study on Heterosis Mechanism of Super-Hybrid Rice

Heterosis is a biological phenomenon whereby the offspring from two parents show improved and superior performance than either inbred parental lines. Hybrid rice is one of the most successful apotheoses in crops utilizing heterosis. Transcriptional profiling of F1 super-hybrid rice Liangyou-2186 and its parents by serial analysis of gene expression （SAGE） revealed 1183 differentially expressed genes （DGs）, among which DGs were found significantly enriched in pathways such as photosynthesis and carbon-fixation, and most of the key genes involved in the carbon-fixation pathway exhibited up-regulated expression in F1 hybrid rice. Moreover, increased catabolic activity of corresponding enzymes and photosynthetic efficiency were also detected, which combined to indicate that carbon fixation is enhanced in F1 hybrid, and might probably be associated with the yield vigor and heterosis in super-hybrid rice. By correlating DGs with yield-related quantitative trait loci （QTL）, a potential relationship between differential gene expression and phenotypic changes was also found. In addition, a regulatory network involving circadian-rhythms and light signaling pathways was also found, as previously reported in Arabidopsis, which suggest that such a network might also be related with heterosis in hybrid rice. Altogether, the present study provides another view for understanding the molecular mechanism underlying heterosis in rice.

Chemical Constituents of Plants from Tribe Chelidonieae and their Bioactivities

The tribe Chelidonieae comprises 23 species of eight genera with an extensive distribution and a long medicinal usage history both in China and Western countries. A large number of chemical constituents have been isolated and identified from the species in tribe Chelidonieae, such as alkaloids, organic acids, and their derivatives, aromatics, triterpenoids, sterols, essential oils, and proteins, most of which possess a variety of bioactivities, especially for the antibacterial, anti-inflammation, antitumor, analgesia, anti-oxidation, and antiparasitic activity. Meanwhile, potential toxicities have been discovered in some constituents. Therefore, the species in tribe Chelidonieae have become a rich source for new drug discovery, biologic study, and mechanism research. This paper presents comprehensive information of the chemical constituents, pharmacological and toxicological research on the plants in tribe Chelidoieae, which is a reference for the plants in this tribe for further development.

Genus llex L.: Phytochemistry, Ethnopharmacology, and Pharmacology

The genus Ilex L. has been used as remedies in traditional Chinese medicine in Aquifoliaceae and beverages for thousands of years due to abundant pharmaceutical bioactivities. There are 600 species in genus IlexL. containing various compounds such as terpenoids, saponins, glycosides, etc. Three species, L cornuta, I. chinensis, and L rotunda have been admitted in Chinese Pharmacopoeia 2015 to treat dyspepsia, stomatitis, and hyperactivity cough and protect the liver and kidney. Recent studies showed that several species have been daily drunk to promote human health and prevent cardiovascular diseases in the folk. Here we reviewed the genus Ilex L. in phytochemistry, ethnopharmacology, and pharmacology.

Dynamic material performance of cold-formed steel hollow sections： a state-of-the-art review

This paper presents a literature review focused on the material performance of cold-formed, carbon steel, hollow structural sections under impulsive （highly dynamic） loading. Impulsive loading, represented by impact and blast, is characterized by a very rapid, time-dependent loading regime in the affected members and materials. Thus, the effect of high-strain-rate loading is initially reviewed. Next the material toughness, an important energy-absorption property and one measure of a material＇s ability to arrest fracture, is considered by means of studying the Charpy V-notch behavior. The response of hollow sections under axial and lateral impact loading is then reviewed. Studies of blast on hollow sections, most of which fall under the categories of contact/near-field loading or far-field loading are presented. Under large-scale field blast experiments, cold-formed hollow sections have shown excellent behavior. Software for modeling blast loading and structural response, the latter including single degree of freedom analysis and explicit finite element analysis, is described and discussed.