Foreign Direct Investment in Electronic Industry in SouthEeast Asia

Since its independence after World War II, Southeast Asia has achieved a lot of economic development and attracted many FDI. The development of its electronics industry has also made considerable achievements, and international electronics giants currently favor it. However, although many international electronics giants are increasing investment in Southeast Asia now, the future of investment in the electronics industry in Southeast Asia may not be smooth sailing. Southeast Asian countries need to make more efforts to attract more investment from foreign electronics giants.Since its independence after World War II, Southeast Asia has achieved a lot of economic development and attracted many FDI. The development of its electronics industry has also made considerable achievements, and international electronics giants currently favor it. However, although many international electronics giants are increasing investment in Southeast Asia now, the future of investment in the electronics industry in Southeast Asia may not be smooth sailing. Southeast Asian countries need to make more efforts to attract more investment from foreign electronics giants

AvaR1, a Butenolide-Type Autoregulator Receptor in Streptomyces avermitilis, Directly Represses Avenolide and Avermectin Biosynthesis and Multiple Physiological Responses

Avermectins are commercially important anthelmintic antibiotics produced by Streptomyces avermitilis. The homologous TetR-family transcriptional regulators AvaR1 and AvaR2 in this species were identified previously as receptors of avenolide, a novel butenolide-type autoregulator signal required for triggering avermectin biosynthesis. AvaR2 was found to be an important pleiotropic regulator in repression of avermectin and avenolide production and cell growth, whereas the regulatory role of AvaR1 remains unclear. Investigation of AvaR1 function in the present study showed that it had no effect on cell growth or morphological differentiation, but inhibited avenolide and avermectin production mainly through direct repression of aco (the key enzyme gene for avenolide biosynthesis) and aveR (the cluster-situated activator gene). AvaR1 also directly repressed its own gene (avaR1) and two adjacent homologous genes (avaR2 and avaR3). Binding sites of AvaR1 on these five target promoter regions completely overlapped those of AvaR2, leading to the same consensus binding motif. However, AvaR1 and AvaR2 had both common and exclusive target genes, indicating that they cross-regulate diverse physiological processes. Ten novel identified AvaR1 targets are involved in primary metabolism, stress responses, ribosomal protein synthesis, and cyclic nucleotide degration, reflecting a pleiotropic role of AvaR1. Competitive EMSAs and GST pull-down assays showed that AvaR1 and AvaR2 competed for the same binding regions, and could form a heterodimer and homodimers, suggesting that AvaR1 and AvaR2 compete and cooperate to regulate their common target genes. These findings provide a more comprehensive picture of the cellular responses mediated by AvaR1 and AvaR2 regulatory networks in S. avermitilis

Efficient heterologous expression of an alkaline lipase and its application in hydrolytic production of free astaxanthin

Abstract Background Astaxanthin, a naturally occurring carotenoid pigment molecule, displays strong antioxidant, anti-cancer, and immunity-enhancing properties, and is often utilized in food, biomedical, cosmetic, and other industries. Free astaxanthin has better solubility than astaxanthin esters (Ast-E), and is a useful auxiliary ingredient in health foods and medicines. Our goal was to establish an improved enzymatic method for preparation of free astaxanthin from natural sources (e.g., the microalga Haematococcus pluvialis), to expand the potential applications of free astaxanthin. Results The alkaline lipase gene proalip and its propeptide were cloned and successfully fusion-expressed in Pichia pastoris X-33. The recombinant lipase was termed Lipase-YH. Through optimization of culture conditions (medium formulation, pH, added methanol concentration), cell growth (OD600) and secreted enzyme activity respectively reached to 280 and 2050 U/mL in a 50-L autofermentor. Activity of Lipase-YH enzyme powder was about 40,000 U/g. Hydrolysis of Ast-E (extracted from H. pluvialis) by Lipase-YH occurred in aqueous phase, and reaction conditions were optimized based on emulsification method and enzyme/substrate ratio. The highest enzymatic reaction rate was observed for substrate concentration 200 μg/mL, with maximal free astaxanthin yield (80%) at 1 h, and maximal Ast-E hydrolysis rate 96%, as confirmed by TLC, HPLC, and mass spectroscopy. Conclusion A novel, efficient enzymatic process was developed for production of free astaxanthin through hydrolysis of Ast-E. Lipase activity was enhanced, and production cost was greatly reduced. The unique structure of free astaxanthin allows linkage to various functional compounds, which will facilitate development of novel pharmaceutical and food products in future studies

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Additional file 4: Table S2. Effects of acetone concentration on Lipase-YH extraction

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Additional file 1: Fig. S1. Analysis of Penicillium cyclopium var. albus lipase gene. A: Signal peptide analysis of the gene by signalP-4.0 Server program. B: Signal peptide and propeptide of the gene. A 20-a.a. signal peptide and 7-a.a. propeptide were found at the start of the 258-a.a. mature lipase

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Additional file 3: Fig. S2. Culture of X33-YH in 7.5-L autofermentor. X33-YH was cultured in a 7.5-L autofermentor following optimization of culture conditions and medium formulation as described in the text. The three processing phases were glycerol batch phase, metal ion mixture fed-batch phase, and methanol induction phase. Samples were taken at 4-h intervals, and cell density (OD600) and enzyme activity were measured. Cell density reached OD600 = 251 at the end of glycerol batch phase (43 h), and methanol 0.5% was added at 44 h. Enzyme production rate increased rapidly between 45 and 60 h, although cell growth was slow. Enzyme activity was 1125.7 U/mL at 60 h. Metal ion mixture was added at 57 h. Enzyme production rate declined abruptly after 60 h, and cell density was fairly constant from 60 to 90 h. At 96 h, enzyme activity reached its maximal value (1575 U/mL), and OD600 was 311

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Additional file 5: Table S3. Comparison of cost of medium before and after using a3-YNB

Prevalence of and factors associated with unintended pregnancies among sexually active undergraduates in mainland China

Plain language summary In this study, we aimed to determine the prevalence and factors associated with UIP among sexually active undergraduates in mainland China. Between September 8, 2019 and January 17, 2020, a total of 48,660 participants were recruited from the Chinese mainland to complete the self-administered, structured, online questionnaire. This analysis was restricted to 6347 sexually experienced, never-married 15–26 year old undergraduates. Based on a social-ecological theoretical framework, we ran separate multivariate Logistic regression models for men and women to identify sociodemographic, familial and individual variables associated with UIP. Our findings indicate that the overall prevalence of UIP was 17.7%. More specifically, 19.5% of male college students reported they had unintentionally gotten a partner pregnant, while 14.9% of female college students became unintentionally pregnant. Students who experienced UIP were more likely to belong to the older age group, live with only one parent or live without parents at home, report that their family members approve of premarital sex, initiate sexual activity younger than 14 years old and have casual sex partners. Furthermore, females with multiple partners and males who came from low-income households, experienced sexual abuse, perceived difficulties in acquiring condoms and did not know how to use condoms correctly were also at higher risk of having an unintended pregnancy. In order to prevent UIP, a comprehensive intervention measure should be taken to target older students and those engaging in risky sexual behaviors, work with young male students to improve condom use skills, improve the availability of free condoms, optimize the involvement of parents and other family members in their children’s sex education