Comparing the protective effects of local and remote ischemic preconditioning against ischemia-reperfusion injury in hepatectomy: a systematic review and network meta-analysis.

Background: Local ischemic preconditioning (LIPC) has been proven to be a protective strategy against hepatic ischemia-reperfusion injury (HIRI) during hepatectomy. Growing evidence suggests remote ischemic preconditioning (RIPC) has the potential to reduce liver injury in hepatectomy. Few studies have directly compared the protective effects of these two mechanical preconditioning strategies. Therefore, we performed a network meta-analysis to compare the efficacy of LIPC and RIPC for hepatic injury during liver resection. Methods: We searched Cochrane, PubMed, Embase, and China National Knowledge Infrastructure (CNKI) from the database inception to January 2023. We included studies directly comparing the effectiveness of LIPC and RIPC and those comparing LIPC or RIPC with no-preconditioning in liver resection. Postoperative liver function and surgical events were analyzed. Data were expressed as standardized mean differences (SMDs) or odds ratios (ORs) and analyzed using network meta-analysis with random effects model. Results: Following the screening of 268 citations, we identified 26 eligible randomized clinical trials (RCTs) involving 1,476 participants (LIPC arm: 789, RIPC arm: 859, no-preconditioning arm: 1,072). LIPC and RIPC were superior to no-preconditioning in reducing postoperative serum transaminase levels [aspartate aminotransferase (AST): SMD RIPC versus no-preconditioning: -2.05, 95% confidence interval (CI): -3.39, -0.71; SMD LIPC versus no-preconditioning: -1.10, 95% CI: -2.07, -0.12; alanine aminotransferase (ALT): SMD RIPC versus no-preconditioning: -2.24, 95% CI: -4.15, -0.32; SMD LIPC versus no-preconditioning: -1.32, 95% CI: -2.63, -0.01]. No significant difference was observed between RIPC and LIPC in postoperative liver function and surgical outcomes (AST: SMD RIPC versus LIPC: -0.95, 95% CI: -2.52, 0.62; ALT: SMD RIPC versus LIPC: -0.91, 95% CI: -3.11, 1.28). In addition, the subgroup analysis revealed the potential benefits of RIPC in improving liver function, especially in patients who diagnosed with cirrhosis or underwent major resection. Conclusions: RIPC and LIPC could serve as effective strategies in relieving HIRI during hepatectomy. No significant differences were observed between LIPC and RIPC, however, RIPC may be an easily applicable strategy to relieve liver injury in hepatectomy.

Mining novel gene targets for improving tolerance to furfural and acetic acid in Yarrowia lipolytica using whole-genome clustered regularly interspaced short palindromic repeats interference library.

Abundant renewable resource lignocellulosic biomass possesses tremendous potential for green biomanufacturing, while its efficient utilization by Yarrowia lipolytica, an attractive biochemical production host, is restricted since the presence of inhibitors furfural and acetic acid in lignocellulosic hydrolysate. Given deficient understanding of inherent interactions between inhibitors and cellular metabolism, sufficiently mining relevant genes is necessary. Herein, 14 novel gene targets were discovered using clustered regularly interspaced short palindromic repeats interference library in Y. lipolytica, achieving tolerance to 0.35 % (v/v) acetic acid (the highest concentration reported in Y. lipolytica), 4.8 mM furfural, or a combination of 2.4 mM furfural and 0.15 % (v/v) acetic acid. The tolerance mechanism might involve improvement of cell division and decrease of reactive oxygen species level. Transcriptional repression of effective gene targets still enabled tolerance when xylose was a carbon source. This work forms a robust foundation for improving microbial tolerance to lignocellulose-derived inhibitors and revealing underlying mechanism.

Symptom structure of posttraumatic stress disorder in workplace trauma: A "distraction-avoidance" pattern.

BACKGROUND: Individuals who experience a workplace trauma are at a high risk of developing posttraumatic stress disorder (PTSD). Most of these people return to work soon after the trauma (i.e., experience early-stage natural exposure). This study aims to explore the response pattern of workers who have experienced a workplace trauma and early-stage natural exposure through network analysis and provide insights into the potential impact of early-stage natural exposure. METHODS: Our study included 278 workers directly experiencing the workplace explosion in the Tianjin Economic and Technological Development Zone. A partial correlation network analysis was used to explore the PTSD symptoms relationship and identify central symptoms. RESULTS: The results suggest that emotional numbness, difficulty in concentration, re-experiencing symptoms, and avoidance of thoughts are the most central symptoms, reflecting a "distraction-avoidance" pattern. CONCLUSIONS: The current study found that workers who experienced workplace trauma exhibited a "distraction-avoidance" pattern, which helps deepen our understanding of the PTSD network and leads to some suggestions on intervention measures.

Gardenia Iridoid Glucosides Protect Against α-Naphthalene Isothiocya-Nate-Induced Cholestatic Rats Through Activation of the FXR-SHP Signaling Pathway.

Introduction: Cholestasis is a common liver disorder that currently has limited treatment options. Gardenia Iridoid Glucosides (GIG) have been found to possess various physiological activities, such as cholagogic, hypoglycemic, antibacterial, and anti-inflammatory effects. The objective of this study was to investigate the effects of GIG on bile acid enterohepatic circulation and explore the underlying mechanism in cholestatic rats. Methods: In order to identify key pathways associated with cholestasis, we conducted Gene Ontology (GO) Enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. In vivo experiments were then performed on alpha-naphthylisothiocyanate (ANIT)-treated rats to assess the impact of GIG. We measured bile flow and various biomarkers including total bilirubin (TB), total bile acids (TBA), total cholesterol (TC), malondialdehyde (MDA), glutamic-pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT), and total superoxide dismutase (T-SOD) in the serum. We also examined the expression levels of bile salt export pump (BSEP), ATP-binding cassette subfamily B member 4 (ABCB4), far-nesoid X receptor (FXR), small heterodimer partner (SHP), cholesterol 7α-hydroxylase (CYP7A1), and sodium taurocholate cotransporting polypeptide (NTCP) in liver tissue. In vitro experiments were conducted on primary hepatocytes to further investigate the mechanism of action of GIG on the expression of SHP, CYP7A1, NTCP, and FXR. Results: Our in vivo experiments demonstrated that GIG significantly increased bile flow and reduced the levels of TB, TBA, TC, MDA, GPT, and GOT, while increasing T-SOD levels in ANIT-treated rats. Addi-tionally, GIG ameliorated liver tissue damage induced by ANIT, upregulated the expression of BSEP and ABCB4, and modulated the protein expression of FXR, SHP, CYP7A1, and NTCP in model rats. In vitro experiments further revealed that GIG inhibited the expression of SHP, CYP7A1, and NTCP by suppressing the expression of FXR. Conclusion: This study provides new insights into the therapeutic potential of GIG for the treatment of cholestasis. GIG demonstrated beneficial effects on bile acid enterohepatic circulation and liver biomarkers in cholestatic rats. The modulation of FXR and its downstream targets may contribute to the mechanism of action of GIG. These findings highlight the potential of GIG as a therapeutic intervention for cholangitis.

Suppressed Auger recombination and enhanced emission of InP/ZnSe/ZnS quantum dots through inner shell manipulation.

Understanding the influence of the inner shell on fluorescence blinking and exciton dynamics is essential to promote the optical performances of InP-based quantum dots (QDs). Here, the fluorescence blinking, exciton dynamics, second-order correlation function g2(τ), and ultrafast carrier dynamics of InP/ZnSe/ZnS QDs regulated by the inner ZnSe shell thickness varying from 2 to 7 monolayers (MLs) were systematically investigated. With an inner ZnSe shell thickness of 5 MLs, the photoluminescence quantum yield (PL QY) can reach 98% due to the suppressed blinking and increased probability of multiphoton emission. The exciton dynamics of InP/ZnSe/ZnS QDs with different inner shells indicates that two decay components of neural excitons and charged trions are competitive to affect the photon emission behavior. The probability density distributions of the ON and OFF state duration in the blinking traces demonstrate an effective manipulation of the inner ZnSe shell in the non-radiative processes via defect passivation. Accordingly, the radiative recombination dominates the exciton deactivation and the non-radiative Auger recombination rate is remarkably reduced, leading to a QY close to unity and a high PL stability for InP/ZnSe/ZnS QDs with 5 MLs of the ZnSe shell. These results provide insights into the photophysical mechanism of InP-based QDs and are significant for developing novel semiconductor PL core/shell QDs.

Efficient sequencing data compression and FPGA acceleration based on a two-step framework.

With the increasing throughput of modern sequencing instruments, the cost of storing and transmitting sequencing data has also increased dramatically. Although many tools have been developed to compress sequencing data, there is still a need to develop a compressor with a higher compression ratio. We present a two-step framework for compressing sequencing data in this paper. The first step is to repack original data into a binary stream, while the second step is to compress the stream with a LZMA encoder. We develop a new strategy to encode the original file into a LZMA highly compressed stream. In addition an FPGA-accelerated of LZMA was implemented to speedup the second step. As a demonstration, we present repaq as a lossless non-reference compressor of FASTQ format files. We introduced a multifile redundancy elimination method, which is very useful for compressing paired-end sequencing data. According to our test results, the compression ratio of repaq is much higher than other FASTQ compressors. For some deep sequencing data, the compression ratio of repaq can be higher than 25, almost four times of Gzip. The framework presented in this paper can also be applied to develop new tools for compressing other sequencing data. The open-source code of repaq is available at: https://github.com/OpenGene/repaq.

Expression patterns and antifungal function study of KaSPI in Mythimna separata.

Kazal-type serine protease inhibitors (KaSPI) play important roles in insect growth, development, digestion, metabolism and immune defence. In this study, based on the transcriptome of Mythimna separata, the cDNA sequence of MsKaSPI with Kazal domain was uploaded to GenBank (MN931651). Spatial and temporal expression analysis showed that MsKaSPI was expressed at different developmental stages and different tissues, and it was induced by 20-hydroxyecdysone in third-instar larvae of M. separata. After 24 h infection by Beauveria bassiana, the expression level of MsKaSPI and the corresponding MsKaSPI content were significantly up-regulated, being 6.42-fold and 1.91-fold to the control group, respectively, while the activities of serine protease, trypsin and chymotrypsin were inhibited. After RNA interference interfered with MsKaSPI for 6 h, the expression decreased by 73.44%, the corresponding content of MsKaSPI protein decreased by 55.66% after 12 h, and the activities of serine protease and trypsin were significantly enhanced. Meanwhile, both the larval and pupal stages of M. separata were prolonged, the weights were reduced and the number of eggs per female decreased by 181. Beauveria bassiana infection also increased the mortality of MsKaSPI-silenced M. separata by 18.96%. These prove MsKaSPI can not only result in slow growth and low fecundity of M. separata by regulating the activity of related protease, but also participate in the resistance to pathogenic fungi by regulating the serine protease inhibitor content and the activities of related serine protease.

Time course of attentional bias and its relationship with PTSD symptoms in bereaved Chinese parents who have lost their only child.

Background: The death of a child is a highly traumatic event for parents and often leads to posttraumatic stress disorder (PTSD). Attentional bias has been demonstrated in the onset and maintenance of PTSD symptoms.Objective: This study aimed to investigate the time course of attentional bias among bereaved Chinese parents who have lost their only child (Shidu parents), and to examine its relationship with PTSD symptoms and symptom clusters.Methods: Shidu parents (n = 38; 50-72 years of age) completed a dot-probe task with negative (trauma-related), positive, and neutral images at four stimulus presentation times (250, 500, 750, and 1250 ms). PTSD symptoms were measured by the PTSD Checklist for DSM-5 (PCL-5).Results: We observed difficulty in disengaging from both negative and positive stimuli at 750 ms and attentional bias away from negative stimuli at 1250 ms. At 1250 ms, attentional avoidance of trauma-related stimuli was positively correlated with PCL-5 total and intrusion scores. Difficulty in disengaging from positive stimuli was negatively correlated with PCL-5 total and intrusion scores as well as negative alterations in cogniti and mood scores.Conclusions: These findings enhance our understanding of attentional bias and cognitive-affective processing in PTSD. This study provides evidence that attentional bias (difficulty in disengaging from positive stimuli and bias away from negative stimuli) are correlated with PTSD symptoms and certain symptom clusters.

The current study examined the time course of attentional bias among bereaved Chinese parents who have lost their only child through a dot-probe task and investigated its relationship with PTSD symptoms and symptom clusters.Participants exhibited difficulty in disengaging from both trauma-related and positive stimuli at 750 ms and exhibited attentional avoidance of trauma-related stimuli at 1250 ms.Attentional avoidance of trauma-related stimuli was positively correlated with PCL-5 total and intrusion scores. Difficulty in disengaging from positive stimuli was negatively correlated with PCL-5 total and intrusion scores as well as negative alterations in cognition and mood scores.

Construction of metal-organic framework-based multienzyme system for L-tert-leucine production.

Chiral compounds are important drug intermediates that play a critical role in human life. Herein, we report a facile method to prepare multi-enzyme nano-devices with high catalytic activity and stability. The self-assemble molecular binders SpyCatcher and SpyTag were fused with leucine dehydrogenase and glucose dehydrogenase to produce sc-LeuDH (SpyCatcher-fused leucine dehydrogenase) and GDH-st (SpyTag-fused glucose dehydrogenase), respectively. After assembling, the cross-linked enzymes LeuDH-GDH were formed. The crosslinking enzyme has good pH stability and temperature stability. The coenzyme cycle constant of LeuDH-GDH was always higher than that of free double enzymes. The yield of L-tert-leucine synthesis by LeuDH-GDH was 0.47 times higher than that by free LeuDH and GDH. To further improve the enzyme performance, the cross-linked LeuDH-GDH was immobilized on zeolite imidazolate framework-8 (ZIF-8) via bionic mineralization, forming LeuDH-GDH @ZIF-8. The created co-immobilized enzymes showed even better pH stability and temperature stability than the cross-linked enzymes, and LeuDH-GDH@ZIF-8 retains 70% relative conversion rate in the first four reuses. In addition, the yield of LeuDH-GDH@ZIF-8 was 0.62 times higher than that of LeuDH-GDH, and 1.38 times higher than that of free double enzyme system. This work provides a novel method for developing multi-enzyme nano-device, and the ease of operation of this method is appealing for the construction of other multi-enzymes @MOF systems for the applications in the kinds of complex environment.

Enhanced acetate utilization for value-added chemicals production in Yarrowia lipolytica by integration of metabolic engineering and microbial electrosynthesis.

The limited supply of reducing power restricts the efficient utilization of acetate in Yarrowia lipolytica. Here, microbial electrosynthesis (MES) system, enabling direct conversion of inward electrons to NAD(P)H, was used to improve the production of fatty alcohols from acetate based on pathway engineering. First, the conversion efficiency of acetate to acetyl-CoA was reinforced by heterogenous expression of ackA-pta genes. Second, a small amount of glucose was used as cosubstrate to activate the pentose phosphate pathway and promote intracellular reducing cofactors synthesis. Third, through the employment of MES system, the final fatty alcohols production of the engineered strain YLFL-11 reached 83.8 mg/g dry cell weight (DCW), which was 6.17-fold higher than the initial production of YLFL-2 in shake flask. Furthermore, these strategies were also applied for the elevation of lupeol and betulinic acid synthesis from acetate in Y. lipolytica, demonstrating that our work provides a practical solution for cofactor supply and the assimilation of inferior carbon sources.

Contribution to the Knowledge of Dicranoptychini (Diptera, Tipuloidea, Limoniidae) in China, with the First Mitochondrial Genome of the Tribe and Its Phylogenetic Implications.

Dicranoptychini is a tribe in the subfamily Limoniinae (Diptera, Tipuloidea, and Limoniidae) and includes only the genus Dicranoptycha Osten Sacken, 1860. However, the species diversity of the tribe in China was seriously underestimated, and the taxonomic status of Dicranoptycha has long been controversial. In this study, types of Chinese Dicranoptycha species and specimens collected from several localities in China were examined, and the first mitochondrial (mt) genome of the tribe Dicranoptychini is presented. Two Dicranoptycha species, D. jiufengshana sp. nov. and D. shandongensis sp. nov., from China, are described and illustrated as new to science. A Palaearctic species, D. prolongata Alexander, 1938, is recorded in China for the first time. In addition, the complete mt genome of D. shandongensis sp. nov. is sequenced and annotated, indicating that it is a typical circular DNA molecule with a length of 16,157 bp and shows a similar gene order, nucleotide composition, and codon usage to mt genomes of other Tipuloidea species. The two pairs of repeat elements are found in its control region. Phylogenetic results confirm the sister-group relationship between Cylindrotomidae and Tipulidae, question the position of the genus Epiphragma Osten Sacken, 1860 in Limoniidae, and indicate that Dicranoptychini may be a basal lineage within Limoniinae.

ISG15 suppresses ovulation and female fertility by ISGylating ADAMTS1.

BACKGROUND: ISGylation is a post-translational protein modification that regulates many life activities, including immunomodulation, antiviral responses, and embryo implantation. The exact contribution of ISGylation to folliculogenesis remains largely undefined. RESULTS: Here, Isg15 knockout in mice causes hyperfertility along with sensitive ovarian responses to gonadotropin, such as increases in cumulus expansion and ovulation rate. Moreover, ISG15 represses the expression of ovulation-related genes in an ISGylation-dependent manner. Mechanistically, ISG15 binds to ADAMTS1 via the ISG15-conjugating system (UBA7, UBE2L6, and HERC6), ISGylating ADAMTS1 at the binding sites Lys309, Lys593, Lys597, and Lys602, resulting in ADAMTS1 degradation via a 20S proteasome-dependent pathway. CONCLUSION: Taken together, the present study demonstrates that covalent ISG15 conjugation produces a novel regulatory axis of ISG15-ADAMTS1 that enhances the degradation of ADAMTS1, thereby compromising ovulation and female fertility.

Plasticity of adipose tissues in response to fasting and refeeding declines with aging in mice.

To explore the plasticity of adipose tissues, C57BL/6J mice at the age of 1 month, 3 months, and 15 months corresponding to adolescence, adulthood, and middle-aged transitional period, respectively, were fasted and refed subsequently at different times. Body adipose tissues ratio (BATR) was calculated, the morphology of adipose tissue and the area of adipocytes were observed by histological analysis, and the mitochondria in adipocytes were observed under the transmission electron microscope. Furthermore, the expression levels of Ucp-1, Cidea, Cox7a1, Cpt-1m, Atgl, and Hsl were detected by qRT-PCR. Our results showed a significant increase in the adipocytes area and body visceral adipose tissue (VAT) ratio in all groups of mice with aging. Moreover, body mesenteric white adipose tissue (mWAT) ratio decreased the most after 72 h fasting. In the middle-aged transitional mice, the white adipocytes did not decrease until 72 h fasting, and most of them still appeared as unaffected unilocular cells. Besides, the number of mitochondria and the expression of Ucp-1, Cidea, Cox7a1, Cpt-1m, Atgl and Hsl were lower in these mice. After 72h refeeding, the body subcutaneous white adipose tissue (sWAT) ratio returned to normal, while the VAT kept decreasing. The above results indicated an impairment in adipose tissue plasticity in mice with aging, suggesting that age modulated the metabolic adaptiveness of adipose tissues in mice.

Network structure and temporal stability of depressive symptoms after a natural disaster among children and adolescents.

Background: Previous studies have found that the postdisaster developmental course of depression is more stable than that of other mental disorders among children and adolescents. However, the network structure and temporal stability of depressive symptoms after natural disasters among children and adolescents remain unknown.Objective: This study aims to understand the depressive symptom network and evaluate its temporal stability among children and adolescents after natural disasters.Methods: Three-wave measurements were conducted among 1,466 children and adolescents at 3, 15, and 27 months following the Zhouqu debris flow. Depressive symptoms were evaluated by the Child Depression Inventory (CDI), which was dichotomised to signify the presence or absence of depressive symptoms. Depression networks were estimated with the Ising model, and expected influence was used to assess node centrality. A network comparison test was used to test the differences in the depression networks among the three temporal points.Results: Overall, the depressive symptom network was temporally stable regarding symptom centrality and global connectivity over the two-year study period. Self-hate, loneliness, and sleep disturbance were central symptoms and had low variability in the depressive networks at the three temporal points. Crying and self-deprecation had large temporal variability in centrality.Conclusion: The present study provides the first evidence for the temporal stability of the youth depressive symptom network postdisaster. The similar central symptoms and connectivity of depression symptoms at different temporal points after natural disasters may partially explain the stable prevalence and developmental trajectory of depression. Self-hate, loneliness, and sleep disturbance could be central characteristics, and sleep disturbance and reduced appetite, sadness and crying, and misbehaviour and disobedience could be key associations in the endurance of depression among children and adolescents after experiencing a natural disaster.

This study provides the first evidence for the temporal stability of the youth depressive symptom network.The depressive symptom network had temporal stability.Self-hate, loneliness, and sleep disturbance were the central symptoms among youths after a natural disaster.

My boss is younger, less educated, and shorter tenured: When and why status (in)congruence influences promotion system justification.

Supervisors are usually older, more educated, and longer tenured than their subordinates, a situation known as status congruence. However, subordinates are increasingly experiencing status incongruence, in which their supervisors lack these traditional status markers. We examine how status congruence versus incongruence interacts with subordinates' judgments of their supervisors' competence to influence subordinates' perceptions of the promotion system. Grounded in system justification theory, we predicted and found that when the supervisor was relatively less competent, status congruence led to perceptions of greater promotion system fairness (Study 1) and promotion system acceptance (Study 2), particularly under conditions known to heighten system justification motivation (a low sense of power in Study 1 and low system escapability in Study 2). Moreover, to triangulate on the role of system justification, we created an implicit measure of the construct and showed in two additional studies (3a and 3b) that participants engaged in more system justification under conditions in which our theoretical rationale suggested they would. Theoretical and practical implications are discussed. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The Predicament and Outlet of Environmental Impact Assessment Mechanism from the Perspective of Risk Society: Taking Japan's Accident-Type Nuclear Sewage Disposal as a Cut-In.

As an important yardstick of social modernization, nuclear technology not only promotes the in-depth development of the national economy but also hangs a sword of Damocles in the field of the risk society. Against the background of the unrest of the nuclear leakage disaster at the Fukushima nuclear power plant, the Japanese government has announced its unilateral decision to discharge nuclear sewage into the sea, undoubtedly putting at least the Pacific Rim countries at huge potential risks. In order to maximize risk reduction and focus on preventive construction in advance, Japan's measures to discharge accident nuclear sewage into the sea have a legitimate basis for the application of an environmental impact assessment system. At the same time, in the process of operation, there are numerous risk dilemmas, such as lack of safety treatment standards, long follow-up disposal cycle and negative domestic supervision system, which need to be broken through one by one. The effective application of the environmental impact assessment system in the Japanese nuclear accident not only helps to reduce the environmental crisis caused by accidental nuclear effluent discharge to the sea but also has a positive and far-reaching international demonstration significance, which helps to better build a foundation of international trust and preventive guarantee system in advance for the possible accidental nuclear effluent treatment in the future.

Highly efficient multiplex base editing: One-shot deactivation of eight genes in Shewanella oneidensis MR-1.

Obtaining electroactive microbes capable of efficient extracellular electron transfer is a large undertaking for the scalability of bio-electrochemical systems. Inevitably, researchers need to pursue the co-modification of multiple genes rather than expecting that modification of a single gene would make a significant contribution to improving extracellular electron transfer rates. Base editing has enabled highly-efficient gene deactivation in model electroactive microbe Shewanella oneidensis MR-1. Since multiplexed application of base editing is still limited by its low throughput procedure, we thus here develop a rapid and efficient multiplex base editing system in S. oneidensis. Four approaches to express multiple gRNAs were assessed firstly, and transcription of each gRNA cassette into a monocistronic unit was validated as a more favorable option than transcription of multiple gRNAs into a polycistronic cluster. Then, a smart scheme was designed to deliver one-pot assembly of multiple gRNAs. 3, 5, and 8 genes were deactivated using this system with editing efficiency of 83.3%, 100% and 12.5%, respectively. To offer some nonrepetitive components as alternatives genetic parts of sgRNA cassette, different promoters, handles, and terminators were screened. This multiplex base editing tool was finally adopted to simultaneously deactivate eight genes that were identified as significantly downregulated targets in transcriptome analysis of riboflavin-overproducing strain and control strain. The maximum power density of the multiplex engineered strain HRF(8BE) in microbial fuel cells was 1108.1 mW/m2, which was 21.67 times higher than that of the wild-type strain. This highly efficient multiplexed base editing tool elevates our ability of genome manipulation and combinatorial engineering in Shewanella, and may provide valuable insights in fundamental and applied research of extracellular electron transfer.

Improving the productivity of malic acid by alleviating oxidative stress during Aspergillus niger fermentation.

BACKGROUND: As an attractive platform chemical, malic acid has been commonly used in the food, feed and pharmaceutical field. Microbial fermentation of biobased sources to produce malic acid has attracted great attention because it is sustainable and environment-friendly. However, most studies mainly focus on improving yield and ignore shortening fermentation time. A long fermentation period means high cost, and hinders the industrial applications of microbial fermentation. Stresses, especially oxidative stress generated during fermentation, inhibit microbial growth and production, and prolong fermentation period. Previous studies have shown that polypeptides could effectively relieve stresses, but the underlying mechanisms were poorly understood. RESULTS: In this study, polypeptides (especially elastin peptide) addition improves the productivity of malic acid in A. niger, resulting in shortening of fermentation time from 120 to 108 h. Transcriptome and biochemical analyses demonstrated that both antioxidant enzyme-mediated oxidative stress defense system, such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), and nonenzymatic antioxidant system, such as glutathione, were enhanced in the presence of elastin peptide, suggesting elastin peptide relieving oxidative stresses is involved in many pathways. In order to further investigate the relationship between oxidative stress defense and malic acid productivity, we overexpressed three enzymes (Sod1, CAT, Tps1) related to oxidation resistance in A. niger, respectively, and these resulting strains display varying degree of improvement in malic acid productivity. Especially, the strain overexpressing the Sod1 gene achieved a malate titer of 91.85 ± 2.58 g/L in 96 h, corresponding to a productivity of 0.96 g/L/h, which performs better than elastin peptide addition. CONCLUSIONS: Our investigation provides an excellent reference for alleviating the stress of the fungal fermentation process and improving fermentation efficiency.

A profile analysis of problematic smartphone usage among college students during coronavirus disease 2019: Relations with the impact of news reports.

The coronavirus disease 2019 (COVID-19) outbreak was the first pandemic to occur in a fully globalized society. The aims of the study were to explore the state of problematic smartphone use (PSU) and its risk factors during this incident. A total of 77,211 college students were surveyed online during the COVID-19 pandemic. Conducting latent profile analysis (LPA), we found the most support for a three-class model of subgroups: over-use group (17.3% of the sample), moderate-use group (54.8% of the sample), mild-use group (27.9% of the sample). The results of multinomial logistic regression show that college students who experienced an extreme negative impact from news reports were more likely to be included in the over-use group than in the mild-use group. These results providing insights that may help foster and develop appropriate and effective solutions to prevent PSU among college students during crises, such as reducing the coverage of negative news report. Supplementary Information: The online version contains supplementary material available at 10.1007/s12144-022-03896-0.