Improving the thermostability of GH49 dextranase AoDex by site-directed mutagenesis

As an indispensable enzyme for the hydrolysis of dextran, dextranase has been widely used in the fields of food and medicine. It should be noted that the weak thermostability of dextranase has become a restricted factor for industrial applications. This study aims to improve the thermostability of dextranase AoDex in glycoside hydrolase (GH) family 49 that derived from Arthrobacter oxydans KQ11. Some mutants were predicted and constructed based on B-factor analysis, PoPMuSiC and HotMuSiC algorithms, and four mutants exhibited higher heat resistance. Compared with the wild-type, mutant S357P showed the best improved thermostability with a 5.4-fold increase of half-life at 60 °C, and a 2.1-fold increase of half-life at 65 °C. Furthermore, S357V displayed the most obvious increase in enzymatic activity and thermostability simultaneously. Structural modeling analysis indicated that the improved thermostability of mutants might be attributed to the introduction of proline and hydrophobic effects, which generated the rigid optimization of the structural conformation. These results illustrated that it was effective to improve the thermostability of dextranase AoDex by rational design and site-directed mutagenesis. The thermostable mutant of dextranase AoDex has potential application value, and it can also provide references for engineering other thermostable dextranases of the GH49 family.

Engineered living materials grown from programmable Aspergillus niger mycelial pellets

The development of engineered living materials (ELMs) has recently attracted significant attention from researchers across multiple disciplines. Fungi-derived ELMs represent a new type of macroscale, cost-effective, environmentally sustainable materials. However, current fungi-based ELMs either have to undergo a final process to heat-kill the living cells or rely on the co-culture with a model organism for functional modification, which hinders the engineerability and versatility of these materials. In this study, we report a new type of ELMs - grown from programmable Aspergillus niger mycelial pellets - by a simple filtration step under ambient conditions. We demonstrate that A. Niger pellets can provide sufficient cohesion to maintain large-area self-supporting structures even under low pH conditions. Subsequently, by tuning the inducible expression of genes involved in melanin biosynthesis, we verified the fabrication of self-supporting living membrane materials with tunable colors in response to xylose concentration in the surroundings, which can be further explored as a potential biosensor for detecting xylose level in industrial wastewater. Notably, the living materials remain alive, self-regenerative, and functional even after 3-month storage. Thus, beyond reporting a new engineerable fungi chassis for constructing ELMs, our study provides new opportunities for developing bulk living materials for real-world applications such as the production of fabrics, packaging materials, and biosensors.

Effects of a Single Bout of Endurance Exercise on Brain-Derived Neurotrophic Factor in Humans: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

We aimed to investigate the impact of a single bout of endurance exercise on the brain-derived neurotrophic factor (BDNF) in humans and analyze how a single bout of endurance exercise impacts the peripheral BDNF types by age group. We performed a systematic literature review by searching PubMed, Elsevier, and Web of Science for studies that included a single bout of endurance exercise in the experimental group and other exercise types in the control group. Eight interventions were included in the study. Overall, a single bout of endurance exercise significantly increased BDNF expression (SMD = 0.30; 95% CI = [0.08, 0.52]; p = 0.001), which was confirmed in the serum BDNF (SMD = 0.30; 95% CI = [0.04, 0.55]; p < 0.001). A non-significant trend was observed in the plasma BDNF (SMD = 0.31; 95% CI = [−0.13, 0.76]; p = 0.017). The serum and plasma BDNF levels significantly increased regardless of age (SMD = 0.35; 95% CI = [0.11, 0.58]; p = 0.004; I2 = 0%). In conclusion, a single bout of endurance exercise significantly elevates BDNF levels in humans without neurological disorders, regardless of age. The serum BDNF is a more sensitive index than the plasma BDNF in evaluating the impact of a single bout of endurance exercise on the BDNF.

[Development of parenting behavior scale for caregivers of children aged 2 to 6 years and analysis for its reliability and validity]

To develop a caregiver parenting behavior scale for children aged 2 to 6 years, and to verify its reliability and validity. This study recruited 1 350 caregivers of children aged 2 to 6 years. The item discrimination analysis and exploratory factor analysis were used to analyze the structure, dimensions and items of the scale. Homogeneity reliability, split-half reliability and test-retest reliability were used to analyze the reliability of the scale. Content validity and construct validity were used to analyze the validity of the scale. The results showed that the final scale contained 7 dimensions and 45 items. Cronbach's α coefficient of the total scale was 0.945; the coefficient of split half was 0.899; the test-retest reliability analysis showed that the correlation coefficients between the two tests were 0.893 (total score), 0.854 (social), 0.832 (language), 0.871 (gross motor), 0.893 (fine motor), 0.862 (cognitive), 0.832 (self-care), and 0.872 (sensory). The content validity analysis was carried out by two rounds of expert argumentation using Delphi expert consultation method. The Kendall coefficient of the items score in two rounds of Delphi expert consultation was 0.813 (P<0.01). The structure validity analysis showed that there were significant correlations between each dimension and the total scale, also between each dimension of the scale, and the extracted average variance values of each dimension was greater than the correlation coefficients between this dimension and other dimensions. In conclusion, the reliability and validity of the scale are qualified. It can be used as a tool to evaluate and guide the parenting behavior of caregivers of children aged 2 to 6 years.

Ultrasensitive electrochemical biosensors based on zinc sulfide/graphene hybrid for rapid detection of SARS-CoV-2

The coronavirus disease 2019 (COVID-19) is a highly contagious and fatal disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In general, the diagnostic tests for COVID-19 are based on the detection of nucleic acid, antibodies, and protein. Among different analytes, the gold standard of the COVID-19 test is the viral nucleic acid detection performed by the quantitative reverse transcription polymerase chain reaction (qRT-PCR) method. However, the gold standard test is time-consuming and requires expensive instrumentation, as well as trained personnel. Herein, we report an ultrasensitive electrochemical biosensor based on zinc sulfide/graphene (ZnS/graphene) nanocomposite for rapid and direct nucleic acid detection of SARS-CoV-2. We demonstrated a simple one-step route for manufacturing ZnS/graphene by employing an ultrafast (90 s) microwave-based non-equilibrium heating approach. The biosensor assay involves the hybridization of target DNA or RNA samples with probes that are immersed into a redox active electrolyte, which are detectable by electrochemical measurements. In this study, we have performed the tests for synthetic DNA samples and, SARS-CoV-2 standard samples. Experimental results revealed that the proposed biosensor could detect low concentrations of all different SARS-CoV-2 samples, using such as S, ORF 1a, and ORF 1b gene sequences as targets. This microwave-synthesized ZnS/graphene-based biosensor could be reliably used as an on-site, real-time, and rapid diagnostic test for COVID-19.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s42114-023-00630-7.

Prevalence and associated factors of self-reported medical errors and adverse events among operating room nurses in China

Background

In recent decades, the prominence of medical errors (MEs) and adverse events (AEs) is fueled by several studies performed across the world. Correspondingly, a high prevalence of medical errors and adverse events have been reported. Operating room nurses (ORNs) were indispensable members of the operating process, and any kind of MEs or AEs from ORNs may cause serious results and even death to the patients. However, to the best of our knowledge, the prevalence and associated factors of MEs and AEs were never reported among ORNs in China, which is the largest country in population and health services quantity in the world.

Methods

This is a cross-sectional study, which was conducted among ORNs in China, and 787 valid questionnaires were analyzed in this study. MEs, AEs, gender, age, married status, religious belief, academic degree, manager or not, working years, working hours/week, physical disease, and mental health were evaluated in this study. MEs were evaluated by eight questions about the occurrence of eight kinds of MEs for the ORNs. For ORNs with MEs, further questions about clinical harm to the patients were interviewed, which analyzed AEs. Kessler 10 was used to evaluate the ORNs' mental health. Logistic regression was conducted to examine the factors associated with MEs and AEs.

Results

The prevalence of MEs and AEs was 27.7 and 13.9% among ORNs, respectively. The most frequent MEs that occurred among ORNs were from surgical instruments (9.1%), disinfection (9.0%), equipment and consumables (8.9%), and specimen management (7.8%). MEs were positively associated with lower working years, poor mental health, and physical disease. The physical disease was positively associated with AEs.

Conclusion

The prevalence of perceived MEs and AEs was at a higher level than other kinds of nurses. Fresh ORNs with physical and mental health problems were the risk population for MEs, and ORNs with physical disease were at a higher risk for AEs. All the findings implied that MEs and AEs were an important issue for ORNs, and ORNs with physical and mental health problems should be paid attention to control MEs and AEs.

Effect of whole-body vibration on neuromuscular activation and explosive power of lower limb: A systematic review and meta-analysis

OBJECTIVE

The review aimed to investigate the effects of whole-body vibration (WBV) on neuromuscular activation and explosive power.

METHODS

Keywords related to whole-body vibration, neuromuscular activation and explosive power were used to search four databases (PubMed, Web of Science, Google Scholar and EBSCO-MEDLINE) for relevant studies published between January 2000 and August 2021. The methodology of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses was used. The eligibility criteria for the meta-analysis were based on PICOST principles. Methodological assessment used the Cochrane scale. Heterogeneity and publication bias were assessed by I2 index and funnel plots, respectively. The WBV training cycle is a random effect model. Publication bias was also assessed based on funnel plots. This study was registered in PROSPERO (CRD42021279439).

RESULTS

A total of 156 participants data in 18 studies met the criteria and were included in the meta-analysis for quantitative synthesis. Results of the meta-analysis showed significant improvements in lower limb neuromuscular activation immediately after WBV compared with the baseline (SMD = 0.51; 95% CI: 0.26, 0.76; p<0.001), and no significant heterogeneity was observed (I2 = 38%, p = 0.07). In addition, the highest increase in lower limb explosive power was observed (SMD = 0.32; 95% CI: 0.11, 0.52; p = 0.002), and no significant heterogeneity (I2 = 0%, p = 0.80) was noted.

CONCLUSIONS

WBV training could improve neuromuscular activation and explosive power of the lower limb. However, due to different vibration conditions, further research should be conducted to determine standardized protocols targeting performance improvement in athletes and healthy personnel experienced in training.

Facile discovery of red blood cell deformation and compromised membrane/skeleton assembly in Prader-Willi syndrome

Prader-Willi syndrome (PWS) is a rare congenital disease with genetic alterations in chromosome 15. Although genetic disorders and DNA methylation abnormalities involved in PWS have been investigated to a significant degree, other anomalies such as those in erythrocytes may occur and these have not been clearly elucidated. In the present study, we uncovered slight anemia in children with PWS that was associated with increased red blood cell (RBC) distribution width (RDW) and contrarily reduced hematocrit (HCT) values. Intriguingly, the increased ratio in RDW to HCT allowed sufficient differentiation between the PWS patients from the healthy controls and, importantly, with individuals exhibiting conventional obesity. Further morphologic examinations revealed a significant deformity in erythrocytes and mild hemolysis in PWS patients. Comprehensive mechanistic investigations unveiled compromised membrane skeletal assembly and membrane lipid composition, and revealed a reduced F-actin/G-actin ratio in PWS patients. We ascribed these phenotypic changes in erythrocytes to the observed genetic defects, including DNA methylation abnormalities. Our collective data allowed us to uncover RBC deformation in children with PWS, and this may constitute an auxiliary indicator of PWS in early childhood.

Associations between Suicidal Ideation and Relatives' Physical and Mental Health among Community Residents: Differences between Family Members and Lineal Consanguinity

(1) Background: Despite the verified relationship between relatives’ characteristics and individual suicidal ideation, few studies have discussed the role of family members and lineal consanguinity independently according to whether they live together with the individuals or not. (2) Methods: The data in this study were collected in November 2019 and identified rural adults over 18 years old in Shandong as the survey objects, with a total of 879 valid cases included in this survey. Logistic regression analysis was employed to examine the risk factors affecting adults’ suicidal ideation and differentiate the effects of a family member and lineal consanguinity’s physical and mental health. Relatives’ physical and mental health were estimated by three aspects: whether they were suffering from chronic diseases, mental illness, or alcoholism. (3) Results: The study showed that a family member’s physical (OR = 2.303, p < 0.01) and mental health (OR = 5.877, p < 0.05) was related to suicidal ideation, but the association between lineal consanguinities’ physical and mental health and suicidal ideation were not supported. People over 40 years old (OR = 6.528, p < 0.05), from only-child families (OR = 4.335, p < 0.01), with household indebtedness (OR = 2.992, p < 0.001), or difficulty falling asleep (OR = 3.165, p < 0.001) had risk factors of suicidal ideation. (4) Conclusions: The physical and mental health of individuals’ family members are related to their suicidal ideation, and their lineal consanguinities’ physical and mental health are not related to suicidal ideation. These findings imply the different associations between family environment, genetic factors, and suicidal ideation. Family members’ health should be considered as a factor to prevent and control suicidal behaviors, including suicidal ideation.

Study on Mix Proportion Optimization and Microstructure of Coal-Based Solid Waste (CSW) Backfill Material Based on Multi-Objective Decision-Making Model

The preparation of underground-backfill material from CSW can be used for large-scale disposal of solid waste. The proportion of backfill material plays an important role in transportation and backfilling effect, and the mix-proportion optimization of backfill material is essentially a multi-factor and multi-objective optimization problem. In this paper, to obtain the mix proportion of backfill materials with optimal comprehensive-evaluation indexes, and suitable for the engineering application, the fluidity and strength of backfill material, mainly composed of coal gangue(CG), fly ash (FA), flue gas desulfurization gypsum (FGD gypsum), and gasification coarse slag (GCS), were tested by single-factor transformation method, and the effects of various solid wastes on the slump-flow, bleeding rate and early strength of backfill material were analyzed. The optimal mix proportion of CSW with the slump-flow, bleeding rate, and 3-day and 7-day strengths as the evaluation indicators is FA: GCS: FGD gypsum: CG = 25%:25%:25%:25%, according to the multi-objective decision model. Furthermore, the comprehensive evaluation index that meets the requirements of mine backfilling is obtained by changing the ordinary portland cement (OPC) content, that is, the optimal OPC content is 10% of the total solid waste, and the mass concentration is 78%. Finally, the pore structure, micromorphology, and composition of the backfill material with the optimal mix proportion were studied by Mercury Intrusion Porosimetry (MIP), X-ray Diffraction (XRD), and Scanning Electron Microscope-Energy Dispersive Spectrometer (SEM-EDS). The research results provide a good reference for the field application of CSW for underground backfilling.

Association between Workplace Violence and Depressive Symptoms among Primary Healthcare Professionals in Shandong, China: Meaning in Life as a Moderator

BACKGROUND

Workplace violence (WPV) is common in healthcare settings. However, the association between WPV and depressive symptoms has not been explored among primary healthcare professionals, especially in China. The assumption of the moderating effort of meaning in life on the association has also not been tested. The purposes of the study are to investigate the relationship between WPV and depressive symptoms and identify the moderating role of meaning in life among primary healthcare professionals in China.

METHODS

In this study, we collected 2530 valid questionnaires. The participants were composed of primary healthcare professionals in Shandong province, China. WPV, meaning in life (including presence of life and search for life), depressive symptoms, and some social-demographic variables were evaluated. The SPSS macro was used to build the moderating relationship.

RESULTS

WPV was positively correlated with depressive symptoms (β = 9.09, p < 0.001), and meaning in life was negatively associated with WPV and depressive symptoms (β = -0.13, p < 0.05) among primary healthcare professionals in China. For primary healthcare professionals with low presence of life, presence of life aggravated the relationship.

CONCLUSIONS

The current study has verified the association between WPV and meaning in life, and the relationship between WPV and depressive symptoms has been supported among primary healthcare professionals in China. Meaning in life and presence of life as moderators play crucial roles in the relationship between WPV and depressive symptoms.

DirectRMDB: a database of post-transcriptional RNA modifications unveiled from direct RNA sequencing technology

With advanced technologies to map RNA modifications, our understanding of them has been revolutionized, and they are seen to be far more widespread and important than previously thought. Current next-generation sequencing (NGS)-based modification profiling methods are blind to RNA modifications and thus require selective chemical treatment or antibody immunoprecipitation methods for particular modification types. They also face the problem of short read length, isoform ambiguities, biases and artifacts. Direct RNA sequencing (DRS) technologies, commercialized by Oxford Nanopore Technologies (ONT), enable the direct interrogation of any given modification present in individual transcripts and promise to address the limitations of previous NGS-based methods. Here, we present the first ONT-based database of quantitative RNA modification profiles, DirectRMDB, which includes 16 types of modification and a total of 904,712 modification sites in 25 species identified from 39 independent studies. In addition to standard functions adopted by existing databases, such as gene annotations and post-transcriptional association analysis, we provide a fresh view of RNA modifications, which enables exploration of the epitranscriptome in an isoform-specific manner. The DirectRMDB database is freely available at: http://www.rnamd.org/directRMDB/.

Associations between Drinking Behaviors and Meaning in Life: Evidence from Primary Care Professionals in China

(1) Background: Although the associations between drinking behaviors and emotional problems have been supported in several previous studies, the associations between drinking behaviors and meaning in life have not been explored until now. We aimed to test the associations between drinking behaviors and meaning in life among primary care professionals, after controlling for depression. (2) Methods: In the current study, we collected 1453 valid questionnaires based on a cross-sectional design. Meaning in life, drinking behaviors, physical diseases, depression, work-related variables, and some other social-demographic variables were evaluated. (3) Results: The results support that after controlling for depression, regular milk drinking (β = 1.387, p = 0.026), and regular juice drinking (β = 2.316, p = 0.030) were associated with higher meaning in life, while regular water drinking (β = −1.448, p = 0.019) was negatively associated with meaning in life. In addition to this, the results showed that the older age (β = 0.098, p = 0.001), preventive medicine majors (β = 4.281, p = 0.013), working fewer days per week (β = −0.942, p = 0.004), licensed (assistant) technician qualification (β = 2.921, p = 0.036), and no depression (β = −0.203, p < 0.001) were positively associated with meaning in life. (4) Conclusion: This study supported the association between drinking behaviors and meaning in life, even after controlling depression. These findings imply that we can further explore this association and its mechanisms in future studies.

Purification and characterization of cold-adapted and salt-tolerant dextranase from Cellulosimicrobium sp. THN1 and its potential application for treatment of dental plaque

The cold-adapted and/or salt-tolerant enzymes from marine microorganisms were confirmed to be meritorious tools to enhance the efficiency of biocatalysis in industrial biotechnology. We purified and characterized a dextranase CeDex from the marine bacterium Cellulosimicrobium sp. THN1. CeDex acted in alkaline pHs (7.5-8.5) and a broad temperature range (10-50°C) with sufficient pH stability and thermostability. Remarkably, CeDex retained approximately 40% of its maximal activities at 4°C and increased its activity to 150% in 4 M NaCl, displaying prominently cold adaptation and salt tolerance. Moreover, CeDex was greatly stimulated by Mg2+, Na+, Ba2+, Ca2+ and Sr2+, and sugarcane juice always contains K+, Ca2+, Mg2+ and Na+, so CeDex will be suitable for removing dextran in the sugar industry. The main hydrolysate of CeDex was isomaltotriose, accompanied by isomaltotetraose, long-chain IOMs, and a small amount of isomaltose. The amino acid sequence of CeDex was identified from the THN1 genomic sequence by Nano LC-MS/MS and classified into the GH49 family. Notably, CeDex could prevent the formation of Streptococcus mutans biofilm and disassemble existing biofilms at 10 U/ml concentration and would have great potential to defeat biofilm-related dental caries.

Application of sludge biochar nanomaterials in Fenton-like processes: Degradation of organic pollutants, sediment remediation, sludge dewatering

In today's society, wastewater sludge has become solid waste, and the preparation of wastewater sludge into sludge biochar nanomaterials (SBCs) for resource utilization has become a promising method. SBCs have advantages over other biomasses, including their complex composition, wide range of raw materials, and especially the presence of various transition metals with catalytic properties. Heterogeneous Fenton processes using SBCs as catalyst carriers have shown great potential in the removal of pollutants. In this review, the synthesis methods of SBCs are reviewed and the effects of different synthesis methods on their physicochemical properties are discussed. Furthermore, the successful applications of raw SBCs, metal-modified SBCs, and Fenton sludge-SBCs in organic pollutant degradation, sediment remediation, and sludge dewatering are reviewed. The mechanisms occurring with different metals as active sites are explored, and the review shows that the degradation efficiency and stability of SBCs are very satisfactory. We also provide an outlook on the future development of SBCs. We hope that this review will help readers gain a clearer and deeper understanding of SBCs and promote the development of SBCs.

Ephedra sinica polysaccharide alleviates airway inflammations of mouse asthma-like induced by PM2.5 and ovalbumin via the regulation of gut microbiota and short chain fatty acid

Objectives

Epidemiological investigations show that long-term exposure to PM2.5 is directly related to asthma-like and other respiratory diseases. This study aims to further explore the pharmacological effect of Ephedra sinica polysaccharide (ESP) on lung injury caused by atmospheric PM2.5.

Methods

To achieve the aim, we explored the therapeutic effect of ESP on an aggravated asthma-like mouse induced by PM2.5 combined with ovalbumin (OVA), and explored mechanisms underlying the connection between gut microbiota and lung function.

Key findings

Preliminary results showed that ESP alleviated the symptoms of aggravated allergic asthma-like in mice; reduced the number of eosinophils in BALF; reduced the levels of serum Ig-E, IL-6, TNF-α, and IL-1β. Further qRT-PCR detected that ESP inhibited the NF-κB pathway. The final analysis detected by 16S rRNA and short chain fatty acid (SCFA) confirmed that ESP increased relative proportions of Bacteroides, Lactobacillus, Prevotella, Butyricicoccus and Paraprevotella, but decreased that of Enterococcus and Ruminococcus; increased acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, and isohexanic acid in the meanwhile.

Conclusions

The study showed that ESP has a potential for future therapeutical applications in the prevention and treatment of asthma-like disease induced by PM2.5 and OVA via regulation of gut microbiota and SCFA.

Plastome-based phylogeny and biogeography of Lactuca L. (Asteraceae) support revised lettuce gene pool categories

This study generated and analyzed complete plastome and internal transcribed spacer (ITS) data of 46 Lactuca species, 13 African endemic (AE) Lactuca species, and 15 species from eight related genera in Lactucinae. The new plastome and nuclear ITS sequences were then used to reconstruct the phylogenetic relationships of Lactuca species. The whole-plastome data were used to estimate divergence time and ancestral area reconstruction of the identified major Lactuca lineages. The results showed that Lactuca species are generally similar in plastome size, Guanine and Cytosine (GC) content, gene structure, and categories, although crop lettuce (Lactuca sativa L.) and its gene pool relatives were found to have one unique pseudogene (ψ ndhF), and accD, atpF, cemA, clpP, and rpl22 showed signs of positive selection. Our phylogenomic analysis demonstrated that Lactuca is monophyletic after excluding Lactuca alatipes Collett and Hemsl and AE Lactuca species. AE Lactuca species are morphologically distinct from core Lactuca lineage and need to be excluded from Lactua. The core Lactuca species most likely originated from Asia-Temperate W ~6.82 Mya and then dispersed globally and formed nine clades. Finally, the lettuce gene pool concept was amended according to the phylogenetic and historical biogeographic analyses. This study revised the circumscription of Lactuca, revealed robust phylogenetic relationships within the genus, and provided insights into Lactucinae phylogeny. The lettuce gene pool species could be used as potential genetic resources for lettuce breeding.

Novel small molecular compound 2JY-OBZ4 alleviates AD pathology in cell models via regulating multiple targets

Alzheimer’s disease (AD) is the most common form of neurodegenerative dementia, characterized by cognitive deficits and memory dysfunction, which is clinically incurable so far. Novel small molecular compound 2JY-OBZ4 is one of structural analogue of Huperzine A (Hup-A), an anti-AD drug in China. In our previous work, 2JY-OBZ4 exhibited potent effects on tau hyperphosphorylation, Aβ production and acetylcholinesterase (AChE) activity. However, 2JY-OBZ4's anti-AD effects and the underlying molecular mechanisms remain unclear. We here reported that 2JY-OBZ4 resisted tau hyperphosphorylation at Thr181 and Ser396 sites in HEK293-hTau cells transfected with GSK-3β, decreased tau phosphorylation via upregulating the activity of PP2A in HEK293-hTau cells and reduced Aβ production through regulating protein levels of APP cleavage enzymes in N2a-hAPP cells. Meanwhile, we found that 2JY-OBZ4 had no adverse effects on cell viability of mice primary neuron even at high concentration, and ameliorated synaptic loss induced by human oligomeric Aβ42. 2JY-OBZ4 had moderate AChE inhibitory activity with the half maximal inhibitory concentration (IC50) to be 39.48 μg/ml in vitro, which is more than two times higher than Hup-A. Together, 2JY-OBZ4 showed promising therapeutic effects in AD cell models through regulating multiple targets. The research provides a new candidate for the therapeutic development of AD.

Effects of transcranial direct current stimulation on motor skills learning in healthy adults through the activation of different brain regions: A systematic review

Objective

This systematic review aims to analyze existing literature of the effects of transcranial direct current stimulation (tDCS) on motor skills learning of healthy adults and discuss the underlying neurophysiological mechanism that influences motor skills learning.

Methods

This systematic review has followed the recommendations of the Preferred Reporting Items for Systematic reviews and Meta-Analyses. The PubMed, EBSCO, and Web of Science databases were systematically searched for relevant studies that were published from database inception to May 2022. Studies were included based on the Participants, Intervention, Comparison, Outcomes, and Setting inclusion strategy. The risk of bias was evaluated by using the Review manager 5.4 tool. The quality of each study was assessed with the Physiotherapy Evidence Database (PEDro) scale.

Results

The electronic search produced 142 studies. Only 11 studies were included after filtering. These studies performed well in terms of distribution, blinding availability and selective reporting. They reported that tDCS significantly improved motor skills learning. The main outcomes measure were the improvement of the motor sequence tasks and specific motor skills. Nine studies showed that tDCS interventions reduced reaction time to complete motor sequence tasks in healthy adults and two studies showed that tDCS interventions improved golf putting task performance.

Conclusion

The included studies showed that tDCS can help healthy adults to improve the motor skills learning by activating different brain regions, such as the primary motor cortex, left dorsolateral prefrontal cortex and right cerebellum. However, the number of included studies was limited, and the sample sizes were small. Therefore, more studies are urgently needed to validate the results of current studies and further explore the underlying neurophysiological mechanisms of tDCS in the future.

Identifying diffusion limiting current to unravel the intrinsic kinetics of electrode reactions affected by mass transfer at rotating disk electrode

Rotating disk electrode systems are widely used to study the kinetics of electrocatalytic reactions that may suffer from insufficient mass transfer of the reactants. Kinetic current density at certain overpotential calculated by the Koutecky-Levich equation is commonly used as the metrics to evaluate the activity of electrocatalysts. However, it is frequently found that the diffusion limiting current density is not correctly identified in the literatures. Instead of kinetic current density, the measured current density normalized by diffusion limiting current density ( j/ jL) has also been frequently under circumstance where its validity is not justified. By taking oxygen reduction reaction/hydrogen oxidation reaction/hydrogen evolution reaction as examples, we demonstrate that identifying the actual diffusion limiting current density for the same reaction under otherwise identical conditions from the experimental data is essential to accurately deduce kinetic current density. Our analysis reveals that j/ jL is a rough activity metric which can only be used to qualitatively compare the activity trend under conditions that the mass transfer conditions and the roughness factor of the electrode are exactly the same. In addition, if one wants to use j/ jL to compare the intrinsic activity, the concentration overpotential should be eliminated.

The Therapeutic Effects of Seven Lycophyte Compounds on Cell Models of Alzheimer’s Disease

Background: As an acetylcholinesterase inhibitor (AChEI), Huperzine-A (Hup-A) is marketed for treatment of mild to moderate Alzheimer’s disease (AD) for decades in China. However, Hup-A causes some side effects. To search for new analogs or derivatives of Hup-A, we produced five Lycophyte alkaloids and two analogues by chemical synthesis: Lyconadins A-E, H-R-NOB, and 2JY-OBZ4. Objective: To systematically evaluated the therapeutic effects of the seven compounds on AD cell models. Methods: We assessed the effects of the seven compounds on cell viability via CCK-8 kit and used HEK293-hTau cells and N2a-hAPP cells as AD cell models to evaluate their potential therapeutic effects. We examined their effects on cholinesterase activity by employing the mice primary neuron. Results: All compounds did not affect cell viability; in addition, Lyconadin A and 2JY-OBZ4 particularly increased cell viability. Lyconadin D and Lyconadin E restored tau phosphorylation at Thr231, and H-R-NOB and 2JY-OBZ4 restored tau phosphorylation at Thr231 and Ser396 in GSK-3β-transfected HEK293-hTau cells. 2JY-OBZ4 decreased the level of PP2Ac-pY307 and increased the level of PP2Ac-mL309, supporting that 2JY-OBZ4 may activate PP2A. Lyconadin B, Lyconadin D, Lyconadin E, H-R-NOB, and 2JY-OBZ4 increased sAβPPα level in N2a-hAPP cells. 2JY-OBZ4 decreased the levels of BACE1 and sAβPPβ, thereby reduced Aβ production. Seven compounds exhibited weaker AChE activity inhibition efficiency than Hup-A. Among them, 2JY-OBZ4 showed the strongest AChE inhibition activity with an inhibition rate of 17% at 10μM. Conclusion: Among the seven lycophyte compounds, 2JY-OBZ4 showed the most expected effects on promoting cell viability, downregulating tau hyperphosphorylation, and Aβ production and inhibiting AChE in AD.

Geographic encoding of transcripts enabled high-accuracy and isoform-aware deep learning of RNA methylation

As the most pervasive epigenetic mark present on mRNA and lncRNA, N⁶-methyladenosine (m⁶A) RNA methylation regulates all stages of RNA life in various biological processes and disease mechanisms. Computational methods for deciphering RNA modification have achieved great success in recent years; nevertheless, their potential remains underexploited. One reason for this is that existing models usually consider only the sequence of transcripts, ignoring the various regions (or geography) of transcripts such as 3′UTR and intron, where the epigenetic mark forms and functions. Here, we developed three simple yet powerful encoding schemes for transcripts to capture the submolecular geographic information of RNA, which is largely independent from sequences. We show that m⁶A prediction models based on geographic information alone can achieve comparable performances to classic sequence-based methods. Importantly, geographic information substantially enhances the accuracy of sequence-based models, enables isoform- and tissue-specific prediction of m⁶A sites, and improves m⁶A signal detection from direct RNA sequencing data. The geographic encoding schemes we developed have exhibited strong interpretability, and are applicable to not only m⁶A but also N¹-methyladenosine (m¹A), and can serve as a general and effective complement to the widely used sequence encoding schemes in deep learning applications concerning RNA transcripts.