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3-Decalinoyltetramic acids (DTAs) are a class of natural products with chemical diversity and potent bioactivities. In fungal species there is a general biosynthetic route to synthesize this type of compounds, which usually features a polyketide synthase-nonribosomal peptide synthetase (PKS-NRPS) and a lipocalin-like Diels-Alderase (LLDAse). Using a synthetic biology approach, combining the bioinformatics analysis prediction and heterologous expression, we mined a PKS-NRPS and LLDAse encoding gene cluster from the plant pathogenic fungus Macrophomina phaseolina and characterized the cluster to be responsible for the biosynthesis of novel DTAs, macrophasetins. In addition, we investigated the biosynthesis of these compounds and validated the accuracy of the phylogeny-guided bioinformatics analysis prediction. Our results provided a proof of concept example to this approach, which may facilitate the discovery of novel DTAs from the fungal kingdom.

The recent increase in online instruction caused by the 2020 pandemic has reignited the debate over the efficacy of online instruction compared to in-person instruction. This study explored the impact various modes of instruction had on student achievement and compared students’ stated modality preference with their actual attendance behavior. Results show that while most students preferred in-person instruction (74%), only 47% of those who indicated they preferred in-person instruction attended class only in-person. Many attended classes utilizing a modality other than in-person, and several students switched their preferred modality away from in-person instruction. In general, students who attended class using a mixed modality or in-person achieved slightly better results than those attending class live online. However, the only statistically significant difference was between those participating predominantly in person and those watching class recordings (88% compared to 84% on average). Overall, many students achieved high grades regardless of their chosen instructional modality. In addition, students reported appreciating the option of multiple modalities when they could not attend class in their preferred modality. These results suggest offering a choice of modalities benefited many students.

Abstract Background Measles outbreaks re-emerged in 2013–2014 in Guangxi Zhuang Autonomous Region of China, where measles immunisation coverage is high. The discrepancy between the vaccination coverage and outbreaks indicates that timeliness is crucial, yet there is limited knowledge on the health system barriers to timely vaccination. Using integrated evidence at the household, village clinic, and township hospital levels, this study aimed to identify the determinants of failure in receiving timely measles vaccinations among children in rural Guangxi. Methods A multi-stage stratified cluster sampling survey with a nested qualitative study was conducted among children aged 18–54 months in Longan, Zhaoping, Wuxuan, and Longlin counties of Guangxi from June to August 2015. The status of timely vaccinations for the first dose of measles-containing vaccine (MCV1) and the second dose of measles-containing vaccine (MCV2) was verified via vaccination certificates. Data on household-level factors were collected using structured questionnaires, whereas data on village and township-level factors were obtained through in-depth interviews and focus group discussions. Determinants of untimely measles vaccinations were identified using multilevel logistic regression models. Results A total of 1216 target children at the household level, 120 villages, and 20 township hospitals were sampled. Children were more likely to have untimely vaccination when their primary guardian had poor vaccination knowledge [MCV1, odds ratio (OR) = 1.72; MCV2, OR = 1.51], had weak confidence in vaccines (MCV1, OR = 1.28–4.58; MCV2, OR = 1.42–3.12), had few practices towards vaccination (MCV1, OR = 12.5; MCV2, OR = 3.70), or had low satisfaction with vaccination service (MCV1, OR = 2.04; MCV2, OR = 2.08). This trend was also observed in children whose village doctor was not involved in routine vaccination service (MCV1, OR = 1.85; MCV2, OR = 2.11) or whose township hospital did not provide vaccination notices (MCV1, OR = 1.64; MCV2, OR = 2.05), vaccination appointment services (MCV1, OR = 2.96; MCV2, OR = 2.74), sufficient and uniformly distributed sessions for routine vaccination (MCV1, OR = 1.28; MCV2, OR = 1.17; MCV1, OR = 2.08), or vaccination service on local market days (MCV1, OR = 2.48). Conclusions Guardians with poor knowledge, weak beliefs, and little practice towards vaccination; non-involvement of village doctors in routine vaccinations; and inconvenient vaccination services in township hospitals may affect timely measles vaccinations among children in rural China. Graphical abstract

Monoterpene indole alkaloids (MIAs) represent a structurally diverse, medicinally essential class of plant derived natural products. The universal MIA building block strictosidine was recently produced in the yeast Saccharomyces cerevisiae, setting the stage for optimization of microbial production. However, the irreversible reduction of pathway intermediates by yeast enzymes results in a non-recoverable loss of carbon, which has a strong negative impact on metabolic flux. In this study, we identified and engineered the determinants of biocatalytic selectivity which control flux towards the iridoid scaffold from which all MIAs are derived. Development of a bioconversion based production platform enabled analysis of the metabolic flux and interference around two critical steps in generating the iridoid scaffold: oxidation of 8-hydroxygeraniol to the dialdehyde 8-oxogeranial followed by reductive cyclization to form nepetalactol. In vitro reconstitution of previously uncharacterized shunt pathways enabled the identification of two distinct routes to a reduced shunt product including endogenous 'ene'-reduction and non-productive reduction by iridoid synthase when interfaced with endogenous alcohol dehydrogenases. Deletion of five genes involved in α,β-unsaturated carbonyl metabolism resulted in a 5.2-fold increase in biocatalytic selectivity of the desired iridoid over reduced shunt product. We anticipate that our engineering strategies will play an important role in the development of S. cerevisiae for sustainable production of iridoids and MIAs.

Pericyclic reactions-which proceed in a concerted fashion through a cyclic transition state-are among the most powerful synthetic transformations used to make multiple regioselective and stereoselective carbon-carbon bonds. They have been widely applied to the synthesis of biologically active complex natural products containing contiguous stereogenic carbon centres. Despite the prominence of pericyclic reactions in total synthesis, only three naturally existing enzymatic examples (the intramolecular Diels-Alder reaction, and the Cope and the Claisen rearrangements) have been characterized. Here we report a versatile S-adenosyl-l-methionine (SAM)-dependent enzyme, LepI, that can catalyse stereoselective dehydration followed by three pericyclic transformations: intramolecular Diels-Alder and hetero-Diels-Alder reactions via a single ambimodal transition state, and a retro-Claisen rearrangement. Together, these transformations lead to the formation of the dihydropyran core of the fungal natural product, leporin. Combined in vitro enzymatic characterization and computational studies provide insight into how LepI regulates these bifurcating biosynthetic reaction pathways by using SAM as the cofactor. These pathways converge to the desired biosynthetic end product via the (SAM-dependent) retro-Claisen rearrangement catalysed by LepI. We expect that more pericyclic biosynthetic enzymatic transformations remain to be discovered in naturally occurring enzyme 'toolboxes'. The new role of the versatile cofactor SAM is likely to be found in other examples of enzyme catalysis.

Background: Acrolein is a significant high priority hazardous air pollutant with pulmonary toxicity and the leading cause of most noncancer adverse respiratory effects among air toxics that draws great attention. Whether and how acrolein exposure impacts pulmonary function remain inconclusive. Objectives: To assess the association of acrolein exposure with pulmonary function and the underlying roles of oxidative DNA damage, inflammation, and pulmonary epithelium integrity. Methods: Among 3,279 Chinese adults from the Wuhan-Zhuhai cohort, associations of urinary acrolein metabolites (N-Acetyl-S-(2-carboxyethyl)-L-cysteine, CEMA; N-Acetyl-S-(3-hydroxypropyl)-L-cysteine, 3HPMA) as credible biomarkers of acrolein exposure with pulmonary function were analyzed by linear mixed models. Joint effects of biomarkers of oxidative DNA damage (8-hydroxy-deoxyguanosine), inflammation (C-reactive protein, CRP), and pulmonary epithelium integrity (Club cell secretory protein, CC16) with acrolein metabolites on pulmonary function and the mediating roles of these biomarkers were assessed. Besides, a subgroup (N = 138) was randomly recruited from the cohort to assess the stabilities of acrolein metabolites and their longitudinal associations with pulmonary function change in three years. Results: Significant inverse dose–response relationships between acrolein metabolites and pulmonary function were found. Each 10-fold increment in CEMA, 3HPMA, or ΣUACLM (CEMA + 3HPMA) was cross-sectionally related to a 68.56-, 40.98-, or 46.02-ml reduction in FVC and a 61.54-, 43.10-, or 50.14-ml reduction in FEV1, respectively (P

Abstract Background The prevalence of stress urinary incontinence (SUI) in adult female in Taiyuan and what are the related risk factors are not clear. The aim of this study was to provide a basis for exploring the prevention and treatment of SUI in adult female in Taiyuan. Methods A voluntary online questionnaire was used to investigate adult female in the community and surrounding townships of Taiyuan. Most of the questionnaires refer to the International Consultation on Incontinence Questionnaire-Female Lower Urinary Tract Symptoms, and adapt to the specific circumstances of the region. Data were analyzed using SPSS software (version 22.0). Results A total of 4004 eligible questionnaires were obtained. The prevalence of SUI in adult female in Taiyuan was 33.5%. Univariate analysis and multivariate logistic regression analysis showed that place of residence, smoking, body mass index, diet, number of deliveries, mode of delivery, dystocia, menopause, oral contraceptives, urinary tract infection, making the bladder empty faster by pushing down and holding urine were risk factors for adult female stress urinary incontinence in Taiyuan. Conclusion The prevalence of SUI in adult female in Taiyuan was high, and based on risk factors identified in this survey, population-level intervention strategies should be developed for the prevention and treatment of adult female SUI in Taiyuan.

We report a case of aseptic abscess in the cavernous body at the base of the penis. In our clinical observation, the patient underwent puncture and drainage of the corpus cavernosum abscess, followed by surgical resection of the abscess wall, with the incisions closed layer by layer with primary suture. In addition, we paid attention to strengthening the postoperative management by using elastic bandages to wrap the penis intermittently to prevent edema; the incision would not be covered with dressings from the third day after the operation, so as to keep the incision site dry in an open way. During the period of indwelling of the catheter after the operation, we noticed the care of the external orifice of the urethra to reduce the occurrence of catheter-related infections. Finally, the patient was diagnosed with a penile aseptic abscess in the cavernous body at the base of the penis. The patient recovered well after surgery and was discharged 1 week later. At 1.5 years after the operation, the shape of the penis returned to normal, and the erectile function was normal. It was seen that good nursing concept is of great help for prognosis, which could avoid infection and edema, and is conducive to wound healing.

This paper explores a way of deploying the classical algorithm named genetic algorithm (GA) with the memristor. The memristor is a type of circuit device with both characteristics of storage and computing, which provides the similarity between electronic devices and biological components, such as neurons, and the structure of the memristor-based array is similar to that of chromosomes in genetics. Besides, it provides the similarity to the image gray-value matrix that can be applied to image restoration with GA. Thus, memristor-based GA is proposed and the experiment about image restoration using memristor-based GA is carried out in this paper. And parameters, such as the size of initial population and the number of iterations, are also set different values in the experiment, which demonstrates the feasibility of implementing GA with memristors.1

Acrylamide (ACR) exposure and consequent health hazards are alarming public health issues that attract worldwide concern. The World Health Organization urges more researches into health hazards from ACR exposure. However, whether and how ACR exposure increases cardiovascular risk remain unclear, and we sought to address these issues in this prospective cohort study conducted on 3024 general adults with 3-year follow-up (N = 871 at follow-up). Individual urinary ACR metabolites (N-Acetyl-S-(2-carbamoylethyl)-L-cysteine [AAMA] and N-Acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine [GAMA]) as credible biomarkers of ACR exposure were detected to assess their cross-sectional and longitudinal relationships with 10-year cardiovascular disease (CVD) risk, a well measure of overall cardiovascular risk. Besides, biomarkers of oxidative stress (urinary 8-hydroxy-deoxyguanosine [8-OHdG] and 8-iso-prostaglandin-F2α [8-iso-PGF2α]) and inflammation (circulating mean platelet volume [MPV] and plasma C-reactive protein [CRP]) as well as plasma transforming growth factor-β1 (TGF-β1) were measured to assess their mediating/mechanistic roles in the relationships of ACR metabolites with 10-year CVD risk. We found AAMA, GAMA, and ΣUAAM (AAMA + GAMA) were cross-sectionally and longitudinally related to increased 10-year CVD risk with odds ratios (95% confidence intervals [CIs]) of 1.32 (1.04, 1.70), 1.81 (1.36, 2.40), and 1.40 (1.07, 1.82), respectively, and risk ratios (95% CIs) of 1.99 (1.10, 3.60), 2.48 (1.27, 4.86), and 2.13 (1.15, 3.94), respectively. Furthermore, 8-OHdG, 8-iso-PGF2α, MPV, CRP, and TGF-β1 were found to significantly mediate 8.06–48.92% of the ACR metabolites-associated 10-year CVD risk increment. In summary, daily ACR exposure of general adults was cross-sectionally and longitudinally associated with increased cardiovascular risk, which was partly mediated by oxidative stress, inflammation, and TGF-β1, suggesting for the first time that ACR exposure may well increase cardiovascular risk of general adult population partly by mechanisms of inducing oxidative stress, inflammation, and TGF-β1. Our findings have important public health implications that provide potent epidemiological evidence and vital mechanistic insight into cardiovascular risk increment from ACR exposure.

Objective: We aim to analyze the effects of polycyclic aromatic hydrocarbons (PAHs) exposure and genetic predisposition on blood lipid through a longitudinal epidemiological study. Methods: We enrolled 4,356 observations who participated at baseline (n = 2,435) and 6-year follow-up (n = 1,921) from Wuhan-Zhuhai cohort. Ten urinary PAHs metabolites and blood lipid (i.e., total cholesterol [TC], triglycerides [TG], low-density lipoprotein cholesterol [LDL-C], and high-density lipoprotein cholesterol [HDL-C]) were measured at both baseline and follow-up. The polygenic risk scores (PRS) of blood lipid were constructed by the corresponding genome-wide association studies. Linear mixed models were fit to identify associations between urinary PAHs metabolites, blood lipid, and lipid-PRSs in the repeated-measure analysis. Besides, longitudinal relationships of blood lipid with urinary PAHs metabolites and respective lipid-PRSs were examined by using linear regression models. Results: Compared with subjects who had persistently low urinary total hydroxyphenanthrene (ΣOHPh), those with persistently high levels had an average increase of 0.137 mmol/l for TC and 0.129 mmol/l for LDL-C over 6 years. Each 1-unit increase of TC-, TG-, LDL-C-, and HDL-C-specific PRS were associated with an average increase of 0.438 mmol/l for TC, 0.264 mmol/l for TG, 0.198 mmol/l for LDL-C, and 0.043 mmol/l for HDL-C over 6 years, respectively. Compared with subjects who had low genetic risk and persistently low ΣOHPh, subjects with high LDL-specific PRS and persistently high ΣOHPh had an average increase of 0.652 mmol/l for LDL-C. Conclusions: Our results suggest that high-level ΣOHPh exposure is associated with an average increase of LDL-C over 6 years, and those relationships can be aggravated by a higher LDL-C-genetic risk. No significant relationships were observed between other PAHs metabolites (including hydroxynaphthalene, hydroxyfluorene, and hydroxypyrene) and blood lipid changes over 6 years. Our findings emphasize the importance of preventing PAHs exposure, particularly among those with a higher genetic predisposition of hyperlipidemia.

The trans-decalin structure formed by intramolecular Diels-Alder cycloaddition is widely present among bioactive natural products isolated from fungi. We elucidated the concise three-enzyme biosynthetic pathway of the cytotoxic myceliothermophin and biochemically characterized the Diels-Alderase that catalyzes the formation of trans-decalin from an acyclic substrate. Computational studies of the reaction mechanism rationalize both the substrate and stereoselectivity of the enzyme.

Nature synthesizes many strained natural products that have diverse biological activities. Uncovering these biosynthetic pathways may lead to biomimetic strategies for organic synthesis of such compounds. In this work, we elucidated the concise biosynthetic pathway of herquline A, a highly strained and reduced fungal piperazine alkaloid. The pathway builds on a nonribosomal peptide synthetase derived dityrosine piperazine intermediate. Following enzymatic reduction of the P450-cross-linked dicyclohexadienone, N-methylation of the piperazine serves as a trigger that leads to a cascade of stereoselective and nonenzymatic transformations. Computational analysis of key steps in the pathway rationalizes the observed reactivities.

Background: The World Health Organization recommends young children aged 6–59 months receive influenza vaccination (IV) annually. This study investigated the IV incidence in a 12-month follow-up period among 24–59 month-old children and identified its predictors based on the theory of planned behavior (TPB). Methods: A population-based random telephone survey was conducted at baseline (March–June 2011) among Chinese parents of 24–59 month-old children in Hong Kong, China, and a follow-up survey was conducted 12 months afterwards (N = 440). Results: The IV prevalence was 63.2% at follow-up (3% increased from baseline). The IV incidence during the follow-up period for all sampled, ever-vaccinated, and never-vaccinated children was 35.6, 58.5, and 7.7 per 100 person-years, respectively. Stratified analyses of logistic regression were performed for the ever-vaccinated and never-vaccinated children. After adjusting for significant socio-demographic variable(s), parental positive attitude, norm, and behavioral intention were significant predictors of IV at follow-up among ever-vaccinated children, while intention was the only significant predictor among never-vaccinated children. Conclusions: Most of the IVs received during the follow-up period were re-vaccinations rather than first-time vaccinations. Efforts should target never-vaccinated children's parents, who reported low incidence and intention. TPB also worked less well among never-vaccinated children, and thus research for other predictors of never-vaccinated children's first-time vaccination are warranted. Promotion programs should consider segmentation by children's prior vaccination status.

The common method for evaluating the extent of grape disease is to classify the disease spots according to the area. The prerequisite for this operation is to accurately segment the disease spots. This paper presents an improved DeepLab v3+ deep learning network for the segmentation of grapevine leaf black rot spots. The ResNet101 network is used as the backbone network of DeepLab v3+, and a channel attention module is inserted into the residual module. Moreover, a feature fusion branch based on a feature pyramid network is added to the DeepLab v3+ encoder, which fuses feature maps of different levels. Test set TS1 from Plant Village and test set TS2 from an orchard field were used for testing to verify the segmentation performance of the method. In the test set TS1, the improved DeepLab v3+ had 0.848, 0.881, and 0.918 on the mean intersection over union (mIOU), recall, and F1-score evaluation indicators, respectively, which was 3.0, 2.3, and 1.7% greater than the original DeepLab v3+. In the test set TS2, the improved DeepLab v3+ improved the evaluation indicators mIOU, recall, and F1-score by 3.3, 2.5, and 1.9%, respectively. The test results show that the improved DeepLab v3+ has better segmentation performance. It is more suitable for the segmentation of grape leaf black rot spots and can be used as an effective tool for grape disease grade assessment.

The structural diversity and biological activities of fungal indole diterpenes (IDTs) are generated in large part by the IDT cyclases (IDTCs). Identifying different IDTCs from IDT biosynthetic pathways is therefore important toward understanding how these enzymes introduce chemical diversity from a common linear precursor. However, IDTCs involved in the cyclization of the well-known aflavinine subgroup of IDTs have not been discovered. Here, using Saccharomyces cerevisiae as a heterologous host and a phylogenetically guided enzyme mining approach, we combinatorially assembled IDT biosynthetic pathways using IDTCs homologues identified from different fungal hosts. We identified the genetically standalone IDTCs involved in the cyclization of aflavinine and anominine and produced new IDTs not previously isolated. The cyclization mechanisms of the new IDTCs were proposed based on the yeast reconstitution results. Our studies demonstrate heterologous pathway assembly is a useful tool in the reconstitution of unclustered biosynthetic pathways.

Aurovertins are fungal polyketides that exhibit potent inhibition of adenosine triphosphate synthase. Aurovertins contain a 2,6-dioxabicyclo[3.2.1]octane ring that is proposed to be derived from a polyene precursor through regioselective oxidations and epoxide openings. In this study, we identified only four enzymes required to produce aurovertin E. The core polyketide synthase produces a polyene α-pyrone. Following pyrone O-methylation by a methyltransferase, a flavin-dependent mono-oxygenase and an epoxide hydrolase can iteratively transform the terminal triene portion of the precursor into the dioxabicyclo[3.2.1]octane scaffold. We demonstrate that a tetrahydrofuranyl polyene is the first stable intermediate in the transformation, which can undergo epoxidation and anti-Baldwin 6-endo-tet ring opening to yield the cyclic ether product. Our results further demonstrate the highly concise and efficient ways in which fungal biosynthetic pathways can generate complex natural product scaffolds.

Background: Phthalates have been largely used for years in varieties of products worldwide. However, research on the joint toxic effect of various phthalates exposure on the liver is lacking. Objectives: We aimed to assess exposure to phthalates on liver function tests (LFTs). Methods: This analysis included data on 6046 adults (≥20 years old) who participated in a National Health and Nutrition Examination Survey (NHANES) in 2007–2016. We employed linear regression and Bayesian kernel machine regression (BKMR), to explore the associations of urinary phthalate metabolites with 8 indicators of LFTs. Results: Di(2-ethylhexyl) phthalate (ΣDEHP) was found to be positively associated with serum alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT) and alkaline phosphatase (ALP) (all P FDR

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein is the main target for neutralizing antibodies. These antibodies can be elicited through immunization or passively transferred as therapeutics in the form of convalescent-phase sera or monoclonal antibodies (MAbs).