Browse Articles

Heart’s desire

Enantioselective Construction of β-Substituted γ-Lactone through Catalytic Asymmetric Oshima–Utimoto Reaction: Divergent Total Syntheses of (−)-Podophyllotoxin and Its Eleven Congeners

Prevalence and determinants of depression, anxiety, and stress among secondary school students

Background By investigating the depression, anxiety and stress status of secondary school students, we further analysed the influencing factors of the changes in depression, anxiety and stress among secondary school students, so as to provide references for subsequent studies and interventions on adolescent mental health. Methods This study was a cross-sectional research study conducted in a city in Southwest China. A questionnaire survey was conducted during March-June 2022 among students attending secondary schools within a city. The surveyed secondary schools were not categorized as public or private. It mainly investigated the general information of middle school students, Depression-Anxiety-Stress Scale (DASS-21), and assessed the mental health status of middle school students. Results A total of 2,716 secondary school students were surveyed, 1,230 males (45.29%) and 1,486 females (54.71%). Among them, 24.4% of the secondary school students had depressive symptoms, 41.4% had anxiety symptoms, and 15.6% had stress; Through logistic regression analysis, attending high school, ranking <60% in academic performance, little or no family psychological support and peer psychological support were the main influencing factors. Conclusion The present study demonstrated that the high school student population, students with an academic ranking of <60%, and students who lacked family/peer psychological support were at higher risk for mental health. These findings provide an empirical basis for developing graded intervention strategies for specific risk factors..

‘Almost unimaginable’: these ants are different species but share a mother

Distribution of myogenic stem cell activator, hepatocyte growth factor, in skeletal muscle extracellular matrix and effect of short-term disuse and reloading

Hepatocyte growth factor (HGF) is a key myogenic stem cell (satellite cells) activator, that resides in the extracellular matrix (ECM). However, HGF distribution in the ECM varies depending on the muscle fiber type. Furthermore, aging impedes the binding of HGF to its receptors owing to nitration by peroxynitrite (ONOO - ). Though oxidative stress increases rapidly during muscle disuse atrophy, satellite cells are rapidly activated upon reloading. In this study, we investigated the distribution of HGF in the ECM in various muscle fiber types, and examined nitration of HGF in disuse and reloading models. Immunofluorescence staining was performed on the soleus (Sol), plantaris (Pla), and gastrocnemius (Gas) muscles of 10-week-old mice. Six mice were used to assess HGF distribution, while 12 mice, divided into control, disuse, and reloading groups were used for qualitative evaluation of nitrated HGF (nitroHGF). Student’s t-tests and the Bonferroni correction were employed for statistical analysis ( p  < 0.05/3 = 0.0167). In Sol muscle, type IIa and IIx muscle fibers exhibited higher HGF distribution in the ECM (61.5 ± 1.0% and 56.7 ± 1.1%, respectively) than type I fibers (32.3 ± 1.0%; p  < 0.001). In Pla and Gas muscle, type IIa 55.8 ± 0.9% and 58.8 ± 1.5%, respectively) and type IIx fibers (49.6 ± 0.9% and 48.9 ± 1.1%, respectively) had significantly higher HGF distribution in the ECM than type IIb fibers (18.6 ± 0.9% and 13.0 ± 1.0%; p  < 0.001, respectively). The amount of nitroHGF increased in the disuse group compared to that in the control group but decreased in the reloading group compared to that in the disuse group. This preferential HGF distribution around type IIa and IIx muscle fibers indicates a distinct mechanism for satellite cell activation, differing from the satellite cell-rich environment associated with type I fibers and the lower HGF association with type IIb fibers. Disuse-induced HGF nitration may inhibit satellite cell activation. Reloading likely triggers mechanisms that counteract nitration, enabling satellite cell reactivation in young muscle.

Separation-Free High-Purity Hydrogen Production via the Mechanochemical Ammonia–Silicon Reaction under Mild Conditions

GWOA: A multi-strategy enhanced whale optimization algorithm for engineering design optimization

This paper analyzes the shortcomings of the traditional Whale Optimization Algorithm (WOA), mainly including the tendency to fall into local optima, slow convergence speed, and insufficient global search ability for high-dimensional and complex optimization problems. An improved Whale Optimization Algorithm (GWOA) is proposed to overcome these issues. By integrating several improvement strategies, such as adaptive parameter adjustment, enhanced prey encircling, and sine-cosine search strategies, GWOA significantly enhances global search ability and convergence efficiency. However, GWOA increases computational complexity, which may lead to longer computation times when handling large-scale problems. It may also fall into local optima in high-dimensional cases. Several experiments were conducted to verify the effectiveness of GWOA. First, 23 classic benchmark functions were tested, covering unimodal, multimodal, and compositional optimization problems. GWOA was compared with other basic metaheuristic algorithms, excellent WOA variants, and the latest algorithms. Then, a comparative scalability experiment is performed on GWOA. The experimental results showed that GWOA achieved better convergence speed and solution accuracy than other algorithms in most test functions, especially in multimodal and compositional optimization problems, with an Overall Efficiency (OE) value of 74.46%. In engineering optimization problems, such as pressure vessel design and spring design, GWOA effectively reduced costs and met constraints, demonstrating stronger stability and optimization ability. In conclusion, GWOA significantly improves the global search ability, convergence speed, and solution stability through multi-strategy integration. It shows great potential in solving complex optimization problems and provides an efficient tool for engineering optimization applications.

Two ants, two species, one mother

Periodic Trends in M–Fe Interactions across an Isostructural and Isoelectronic Series of [MFe₃S₄] Clusters (M = V, Cr, Mo, W)

The deciduous genital spines of the moth Peridea anceps (Goeze, 1781): Potential socially transferred materials

The genitalia of Lepidoptera are complex structures that evolve rapidly and divergently. The endophallus of many lepidopterans is ornamented with elaborate sclerotized structures known as cornuti. In some species, the cornuti are deciduous and remain within the female genital tract after copulation; the function of these structures is virtually unknown. These structures are a peculiar potential type of secondary “socially transferred material” (the primary materials are spermatozoids, i.e., genetic material), because they probably influence the physiology and behaviour of receivers (i.e., females) but are not molecules that function as allohormones. Such influence could be achieved by acting as mating plugs or via mechanical stimulation of females. The most intriguing and bizarre deciduous cornuti are the so-called caltrop cornuti, star-shaped structures, composed of several rays radiating from a central mass. Despite the presence of caltrop cornuti in at least 400 species, there are no studies of their microscopic structure and mechanism of dislodgement and transference to the female. In this study, we describe in detail the general and microscopic structure of the caltrop cornuti and associated structures of the prominent moth Peridea anceps (Notodontidae). We provide quantitative data of the cornuti and, for the first time, we explain the processes of detachment and transference to the female genital tract; we also describe their distribution inside the female genitalia. We discuss the possibility that one of the functions of deciduous caltrop cornuti is protection against sperm competition, as well as their potential influence on other aspects of the behaviour and physiology of females via mechanical stimulation.

Daily briefing: How bad are ultra-processed foods, really?

Early childhood caries intervention in Aboriginal Australian children: Follow-up at child age 9 years

Objective Dental caries is one of the most common preventable diseases among Indigenous children. The study aimed to estimate the efficacy of an Early Childhood Caries (ECC) intervention among Aboriginal Australian children over 9 years, and to explore potential risk factors associated with dental caries among Indigenous Australian children. Methods Data were from a randomized controlled trial conducted in South Australia, Australia. Four hundred and forty-eight women pregnant with an Aboriginal child were randomly allocated to either an immediate (II) or delayed (DI) intervention group between January 2011 and May 2012. The immediate intervention comprised (1) provision of dental care to mothers during pregnancy; (2) application of fluoride varnish to teeth of children at ages 6, 12; and 18 months; (3) motivational interviewing delivered in conjunction with; and (4) anticipatory guidance. Mothers/children in the DI group received the same intervention commencing at child aged 2 years. Follow-ups occurred when children were aged 2-, 3-, 5-, 7- and 9-years. In this analysis, outcomes were severity of caries experience: mean dmft/DMFT at child aged 9 years. Dependent variables included mothers’ baseline and seven years follow-up characteristics (age, education level, source of income, residential location, smoking and alcohol status) and children’s birth and feeding, and dental behaviours characteristics (sex, gestation, birth weight, breastfeeding status and sweet food consumption, and frequency of tooth brushing). Multivariable log-Poisson regression models with robust standard error estimation were applied as a statistical model to estimate multivariable relationships of dental caries and other covariates. Risk ratios (RRs) with their 95%CI were calculated. Sensitivity analyses were conducted by using the inverse-probability-of censoring weighting (IPCW) to overcome the loss-follow-up issues. Results Data were available for 367 (II = 180 and DI = 187) children at age 9 years. The mean dmft was 3.41 (95% CI: 2.95–3.87) and DMFT was 0.31(95%CI: 0.22–0.41). In multivariable modelling, mean dmft was higher (RR = 1.13, 95% CI: 1.01–1.26) among DI children than II children, but there were no significant differences in the permanent dentition. Risk factors for caries severity in both the primary and permanent dentition included lower mothers’ education level (<12 years level: dmft; RR = 1.56, 95% CI:1.31–1.86; and ‘Trade or TAFT: DMFT: RR =3.40, 95%CI: 1.16-9.98). Other risk factors for dental caries experience in the primary dentition included preterm birth, low birth weight, child not breastfed and sugar consumption more than 10%, and in permanent dentition was self-rated ‘fair/poor’ or ‘Good’ children’s oral health, compared with self-rated ‘Excellent/very good’ oral health. Conclusion The present study suggests that, within this cohort, initiating an early childhood caries intervention during pregnancy and infancy may be associated with lower caries experience in the primary dentition by age 9 years compared to a later start. Low maternal education level was associated with caries severity in both primary and permanent dentitions. Sugar consumption, a modifiable risk factor, greater than 10% was an important contributor to dental caries in primary teeth.

Photochemistry of Sulfur Dioxide Mediated by Charge Transfer through Intermolecular Chalcogen Bonds

Daily and seasonal human mobility modulates temperature exposure in European cities

Extreme temperatures pose a serious threat to human health, especially in urban areas where the majority of the world population is living. Temperature-related risks are exacerbated by urban-induced warming but existing exposure assessments rely on a static residential population, thus overlooking space-time changes in population density and their covariation with urban temperatures. Here we combine 1-km monthly daytime and nighttime population estimates for 80 European cities with existing high-resolution urban climate simulations to quantify the impact of daily and seasonal mobility on residents’ exposure to heat and cold. Using city-specific exposure-response curves and the respective minimum mortality temperatures as thresholds to define hazardous conditions we calculated that, on daily timescales, commuting towards city centers causes a 7.8% average increase (IQR:1.0-12.9%) in summer heat exposure but, during winter, it provides a slight protective effect against cold. On seasonal timescales, changes in total population are out of phase with the temperature cycle in most European cities, leading to a lower exposure to heat, with the exception of touristic destinations where exposure increases, on average, by 0.9% during the warmest months. These results highlight the key role of human mobility for heat risk assessment and adaptation and they reveal the existence of general exposure trends that hold across diverse cities and climates.

Migrating Group Strategy for Remote Functionalization of Seven-Membered Rings

Experts contributions to the development of a non-sugar sweeteners warning label for Brazilian food products

The consumption of non-sugar sweeteners (NSS) has been associated with potential health risks, including glucose intolerance, alterations in the intestinal microbiota which lead to metabolic abnormalities including pancreatic endocrine dysfunction, aggravation of kidney disease, increased risk of cancer and adverse cardiovascular outcomes. In Brazil, the presence of NSS in ultra-processed food products (UPFP) is only reported in ingredient lists, which Brazilian consumers struggle to locate and understand. On the other hand, countries such as Argentina and Mexico have implemented a cautionary legend for NSS in packaged foods and beverages. This study aimed to evaluate expert opinion on the design attributes of NSS warning labels intended to inform consumers about the presence of these sweeteners in packaged foods and beverages sold in Brazil. For this purpose, a panel of experts was conducted to discuss, judge and decide on the technical aspects of readability, visibility, attention, perceived healthiness and health risk of the proposed warning labels for NSS in packaged foods and beverages in Brazil. Based on the specific attributes, the experts identified two NSS warning messages as the most suitable: ‘Attention: contains non-sugar sweetener — not recommended for children and for weight control’ and ‘Attention: contains non-sugar sweetener’. According to the experts, these messages should be displayed as front-of-package warnings in black rectangular boxes with white text, beginning with the signal word ‘Attention’ and positioned on the main panel near the Brazilian front-of-package nutrition labeling. The study provides interdisciplinary evidence and expert insight, to support the development of NSS warning labels in Brazil.

The diversity of microbial enzymes that turn a pollutant into an inert gas

Cobalt(0)-Catalyzed Isomerization of Allylamines Promoted by Monodentate Benzofuran Phosphines

Adaptive force-position-speed collaborative process planning and roughness prediction for robotic polishing

In this study, an adaptive force-position-speed collaborative process planning framework for robot polishing was proposed to improve the stability of the robot polishing process. The material removal model based on Preston’s theory was studied, and the factors of polishing pressure, tool speed, feed speed, and sandpaper type were considered to design the manual polishing experiment. The improved Dung Beetle Optimization algorithm, Back Propagation Neural Network, Finite Element Analysis, and Response Surface Methodology provide a strong guarantee for the selection of robot polishing process parameters. For curved workpieces, the curvature adaptive interpolation method is introduced to generate trajectories. An adaptive impedance control strategy is implemented to enhance force control, and PD iteration and RBF neural networks are used to ensure stable contact force and accuracy. The experimental results show that the root mean square error (RMSE) accuracy of the established roughness prediction model reaches 0.0001 µm, the proposed force control method is more stable, and the surface roughness is reduced by 20.79% on average compared to the baseline method, which proves the effectiveness of the framework in achieving high precision and high efficiency of robot polishing.

Activation and proliferation profiles of M.tuberculosis specific dual functional CD4+T cells from smear negative pulmonary TB patients

Background Tuberculosis is a major public health challenge in the resource-limited endemic setting of sub-Saharan Africa. The diagnostic challenge becomes worse for smear-negative TB cases. Even if efforts for non-sputum-based TB diagnostic and prognostic biomarkers, there was limited data on blood-based immunological biomarkers among smear-negative PTB patients.Therefore, we assessed the phenotypic profile (HLA-DR, CD-38, Ki-67) of M. tuberculosis specific CD4 + T cells expressing dual IFN-γ and TNF-α cytokines from smear negative PTB patients in Addis Ababa, Ethiopia. Methodology An institutional-based longitudinal cohort study was conducted in Addis Abeba, Ethiopia, on new smear-negative PTB who were adult and HIV-negative in comparison with multiple comparator groups. A total of 149 (confirmed patients with non-TB respiratory disease −33, smear-negative TB-29, smear-positive TB-34, apparently healthy – 53) study participants was enrolled. The expression level of activation (HLA-DR, CD-38) and proliferation (Ki-67) markers from dual IFN-γ and TNF-α cytokines expressing PPD specific CD4 + T cells were assessed after surface and intracellular cytokine staining. To confirm the presence of M. tuberculosis , MGIT/LJ culture, PCR, and smear microscopy were performed. Result The overall level of HLA-DR and CD-38 expression in smear-negative and positive pulmonary TB patients were substantially higher than that of confirmed non-TB respiratory illness, apparently healthy QFT positive and negative study participants (p-value = 0.0127, p-value < 0.0001, p-value = 0.0043, p-value <0.0001, respectively) before commencing anti TB treatment. Also, among the smear-negative and positive pulmonary TB cohort, the expression of CD-38, HLA-DR, and HLA-DR + CD-38 + expression was reduced in the second month and six-month cohort compared with baseline data (p-value= < 0.0001, p-value = 0.00365, p –value = 0.0001, respectively). Conclusion In this study, we found the diagnostic and prognostic potential of activation markers, particularly CD-38, in smear-negative PTB patients from dual M. tuberculosis-specific IFN-γ + TNF-α+ cytokine producing CD4 + T cells in both the presumed ex vivo and antigen-specific stimulation assays.