Intercultural Friendships with International Students in China: Examining the Role of Intergroup Contact, Intercultural Communication Competence, Host Country Nationals' Attitudes, and Perceived Intergroup Threats.

International students studying and living in a foreign context often complain about difficulties establishing friendships with host nationals. This study investigates host country nationals' (HCNs) willingness to develop intercultural friendships with international students who are sojourning in China by exploring the effects of face-to-face and online intergroup contact, HCNs' attitudes, intercultural communication competence (ICC), and perceived intergroup threats. Survey data from 469 HCNs indicate that (a) face-to-face and online contact are indirectly and positively related to their willingness to form intercultural friendships, (b) face-to-face contact can moderate the relationships of online contact with HCNs' intergroup attitudes and perceived intergroup threats, and (c) both ICC and intergroup attitudes can positively predict friendship formation whereas perceived intergroup threats act as a negative predictor. The implications of our findings for future research and practice are presented.

How social media usage affects psychological and subjective well-being: testing a moderated mediation model.

BACKGROUND: A growing body of literature demonstrates that social media usage has witnessed a rapid increase in higher education and is almost ubiquitous among young people. The underlying mechanisms as to how social media usage by university students affects their well-being are unclear. Moreover, current research has produced conflicting evidence concerning the potential effects of social media on individuals' overall well-being with some reporting negative outcomes while others revealing beneficial results. METHODS: To address the research gap, the present research made an attempt to investigate the crucial role of social media in affecting students' psychological (PWB) and subjective well-being (SWB) by testing the mediating role of self-esteem and online social support and the moderation effect of cyberbullying. The data in the study were obtained from a sample of 1,004 college students (483 females and 521 males, Mage = 23.78, SD = 4.06) enrolled at 135 Chinese universities. AMOS 26.0 and SPSS 26.0 as well as the Process macro were utilized for analyzing data and testing the moderated mediation model. RESULTS: Findings revealed that social media usage by university students was positively associated with their PWB and SWB through self-esteem and online social support, and cyberbullying played a moderating role in the first phase of the mediation process such that the indirect associations were weak with cyberbullying reaching high levels. CONCLUSION: These findings highlight the importance of discerning the mechanisms moderating the mediated paths linking social media usage by young adults to their PWB and SWB. The results also underline the importance of implementing measures and interventions to alleviate the detrimental impacts of cyberbullying on young adults' PWB and SWB.

Structure-based discovery of nonhallucinogenic psychedelic analogs.

Drugs that target the human serotonin 2A receptor (5-HT2AR) are used to treat neuropsychiatric diseases; however, many have hallucinogenic effects, hampering their use. Here, we present structures of 5-HT2AR complexed with the psychedelic drugs psilocin (the active metabolite of psilocybin) and d-lysergic acid diethylamide (LSD), as well as the endogenous neurotransmitter serotonin and the nonhallucinogenic psychedelic analog lisuride. Serotonin and psilocin display a second binding mode in addition to the canonical mode, which enabled the design of the psychedelic IHCH-7113 (a substructure of antipsychotic lumateperone) and several 5-HT2AR ß-arrestin-biased agonists that displayed antidepressant-like activity in mice but without hallucinogenic effects. The 5-HT2AR complex structures presented herein and the resulting insights provide a solid foundation for the structure-based design of safe and effective nonhallucinogenic psychedelic analogs with therapeutic effects.

Two new streptovaricin derivatives from mutants of Streptomyces spectabilis CCTCC M2017417.

Two new ansamycin derivatives, damavaricin H (1) and protostreptovaricin VI (2) were isolated from the Streptomyces spectabilis CCTCC M2017417 derived mutants of ΔstvP5 and ΔstvA2, respectively. The structures of 1 and 2 were established by analysis of the HRESIMS as well as 1D and 2D NMR datasets. The minimum inhibitory concentration (MIC) results showed that compounds 1 and 2 possessed the corresponding anti-MRSA bioactivities of 4 ∼ 8 µg/ml and 8 ∼ 16 µg/ml, which confirmed the structure-activity relationships of streptovaricins reported previously and also revealed that addition of the hydroxyl group at C-8 increased the anti-MRSA activity.

Evaluation of Rpf protein of Micrococcus luteus for cultivation of soil actinobacteria.

Rpf protein, a kind of resuscitation promoting factor, was first found in the culture supernatant of Micrococcus luteus. It can resuscitate the growth of M. luteus in "viable but non-culture, VBNC" state and promote the growth of Gram-positive bacteria with high G + C content. This paper investigates the resuscitating activity of M. luteus ACCC 41016T Rpf protein, which was heterologously expressed in E. coli, to cells of M. luteus ACCC 41016T and Rhodococcus marinonascens HBUM200062 in VBNC state, and examines the effect on the cultivation of actinobacteria in soil. The results showed that the recombinant Rpf protein had resuscitation effect on M. luteus ACCC 41016T and R. marinonascens HBUM200062 in VBNC state. 83 strains of actinobacteria, which were distributed in 9 families and 12 genera, were isolated from the experimental group with recombinant Rpf protein in the culture medium. A total of 41 strains of bacteria, which were distributed in 8 families and 9 genera, were isolated from the control group without Rpf protein. The experimental group showed richer species diversity than the control group. Two rare actinobacteria, namely HBUM206391T and HBUM206404T, were obtained in the experimental group supplemented with Rpf protein. Both may be potential new species of Actinomadura and Actinokineospora, indicating that the recombinant expression of M. luteus ACCC 41016T Rpf protein can effectively promote the isolation and culture of actinobacteria in soil.

The Mechanism of Dehydrating Bimodules in trans-Acyltransferase Polyketide Biosynthesis: A Showcase Study on Hepatoprotective Hangtaimycin.

A bioassay-guided fractionation led to the isolation of hangtaimycin (HTM) from Streptomyces spectabilis CCTCC M2017417 and the discovery of its hepatoprotective properties. Structure elucidation by NMR suggested the need for a structural revision. A putative HTM degradation product was also isolated and its structure was confirmed by total synthesis. The biosynthetic gene cluster was identified and resembles a hybrid trans-AT PKS/NRPS biosynthetic machinery whose first PKS enzyme contains an internal dehydrating bimodule, which is usually found split in other trans-AT PKSs. The mechanisms of such dehydrating bimodules have often been proposed, but have never been deeply investigated. Here we present in vivo mutations and in vitro enzymatic experiments that give first and detailed mechanistic insights into catalysis by dehydrating bimodules.

Antibacterial natural products lobophorin L and M from the marine-derived Streptomyces sp. 4506.

Two new spirotetronate natural products, lobophorin L (1) and lobophorin M (2), together with three known lobophorin-like spirotetronate antibiotics (3-5) and two known ansamycins (6-7), were isolated from the marine-derived Streptomyces sp. 4506. The structures of 1 and 2 were established on the basis of HRESIMS as well as 1D and 2D NMR datasets. Antibacterial assay showed that, compounds 1 and 3-5 exhibited strong to moderate antibacterial activities against Micrococcus luteus and Bacillus thuringiensis with MIC values ranging from 0.0625 to 8 µg/mL, while compounds 3 and 6 showed weak antibacterial activities against Staphylococcus aureus and MRSA. The antibacterial activities of the lobophorins in this study indicated that the more substitution number of the sugar moieties at C-9 of the lobophorin, the stronger antimicrobial properties it may deserve, and the higher the oxidation degree of substituent group at C-3D, the better antibacterial activities of its corresponding compound could be.

SHARPIN regulates cell proliferation of cutaneous basal cell carcinoma via inactivation of the transcriptional factors GLI2 and c­JUN.

SHANK­associated RH domain­interacting protein (SHARPIN) is a component of the linear ubiquitin chain assembly complex that can enhance the NF­κB and JNK signaling pathways, acting as a tumor­associated protein in a variety of cancer types. The present study investigated the role of SHARPIN in cutaneous basal cell carcinoma (BCC). Human BCC (n=26) and normal skin (n=5) tissues, and BCC (TE354.T) and normal skin (HaCaT) cell lines were used to evaluate SHARPIN expression level using immunohistochemistry and western blotting, respectively. A lentivirus carrying SHARPIN­targeting or negative control short hairpin RNA was infected into TE354.T cells, and the infected stable cells were assayed to analyze tumor cell proliferation, cell cycle, apoptosis, migration and invasion by Cell Counting Kit­8 and 5­ethynyl­2'­deoxyuridine incorporation assays, flow cytometry and Transwell assays. Western blotting was performed to assess the protein expression levels of gene signaling in SHARPIN­silenced BCC cells. SHARPIN protein expression levels were downregulated or absent in BCC cancer nests and precancerous lesions compared with normal skin samples. In addition, SHARPIN expression levels were lower in TE354.T cells compared with HaCaT cells. SHARPIN shRNA enhanced tumor cell proliferation and the S phase of the cell cycle, whereas BCC cell apoptotic rates, and migratory and invasive abilities were not significantly altered. The expression levels of cyclin D1, cyclin­dependent kinase 4, phosphorylated­c­JUN and GLI family zinc finger 2 proteins were increased, whereas Patched 1 (PTCH1) and PTCH2 were decreased in the SHARPIN­shRNA­infected BCC cells. Therefore, the present results suggested that SHARPIN may act as a tumor suppressor during BCC development.

Gynurincola endophyticus gen. nov., sp. nov., a novel bacterium of the family Chitinophagaceae.

A Gram-stain-negative, rod-shaped (0.2-0.4 µm×1.2-1.7 µm), endophytic bacterium, designated HBUM179779T, was isolated from the stem of a medicinal plant,Gynura bicolor, collected from Pixian county in Sichuan province, China. The strain did not produce endospores and its cells could secrete mucus. The predominant menaquinone was MK-7. The polar lipids were phosphatidylethanolamine, phosphatidylinositolmannosides, two unknown aminolipids, two unknown glycolipids and an unknown phospholipid. Branched fatty acids (iso-) and hydroxy fatty acids were the main fatty acids, which mainly included iso-C15 : 0, iso-C15 : 1 G and iso-C17 : 0 3-OH. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain HBUM179779T fell within the family Chitinophagaceae, and its closest neighbour was Pseudoflavitalea rhizosphaerae T16R-265T (94.46 %). However, strain HBUM179779T did not make a coherent clade with members of the recognized organisms. The average nucleotide identity value between strain HBUM179779T and Pseudoflavitalea rhizosphaerae T16R-265T was 67.1 %. On the basis of the phylogenetic and phenotypic characteristics of this bacterium, a novel genus and species, Gynurincola endophyticus gen. nov., sp. nov., is proposed. The type strain is HBUM179779T (=CGMCC 1.15525T=NBRC 112424T).

Down-regulated SHARPIN may accelerate the development of atopic dermatitis through activating interleukin-33/ST2 signalling.

SHARPIN is an important component of the linear ubiquitin chain assembly complex (LUBAC). Loss of function of SHARPIN results in eosinophilic inflammation in multiple organs including skin with Th2 -dominant cytokines and dysregulated development of lymphoid tissues in mice. The clinicopathological features are similar to atopic dermatitis (AD) in humans. In order to investigate the potential role of SHARPIN in the pathogenesis of AD, we performed genetic association study of the genotypes and haplotypes as well as SHARPIN's expression between AD cases and controls. We found three mutations (g.480G>A, g.4576A>G and g.5070C>T) in patient group, and significantly decreased expression in AD lesions, suggesting a primary role of SHARPIN during AD development. Lentivirus-mediated in vitro assays identified that knockdown of SHARPIN can induce elevated expression of IL-33 and its orphan receptor ST2, FLG and STAT3 and NF-κB inactivation in HaCaT keratinocytes, which has been widely evidenced in regulating AD development. ST2 expression was highly induced in SHARPIN-silenced HaCaT keratinocytes after the combined stimulation of IL-4 and IL-13. Our in vivo and in vitro findings implicated that SHARPIN may be a novel participant in the pathogenesis and/or new therapeutic target of AD.