Higher Proportion Research Articles

What our children lost and gained at the time of school closure during the Covid-19 pandemic: a study on psychological distress, behavioural concerns and protective factors of resilience among preschool children in Kerala, India

BackgroundThe pandemic has put at risk the social and emotional development of children on account of the paucity of arenas for social interaction. This study from Kerala, India was conducted to assess the resilience factors, behavioural concerns, psychological distress symptoms among the children aged 3 to 5 years. We also tried to look into the lost opportunities that could have aided the social and emotional development of children like peer interaction, child care hours.MethodsThe cross-sectional study was conducted among the children aged 3 to 5 years. A total of 535 children attending the immunisation clinics were enrolled by consecutive sampling. Devereux Early Childhood Assessment P2 (DECA P2) questionnaire was used to assess the levels of resilient factors and behavioural concerns in the study population.ResultsWe observed a high proportion of children in the area of need category of protective factors under DECA P2. The proportion of children falling under area of concern was 64.5%, 49%, 68.4% for attachment/relationship, self-regulation, and initiative respectively. 24.9% study subjects have a behavioural concern score that puts them in the area of need category. The logistic regression model we created identified ‘Male Gender,’ ‘Mothers could spend only less time for child care’ and ‘electronic devices used as pacifier’ as significant predictors for belonging to Area of need Behavioural Concerns T score category.ConclusionA large proportion of children aged between 3 to 5 years with reported behavioural concerns and lack of protective factors for socioemotional development. This can be attributed partly to the ongoing pandemic and its associated restrictions. The increased child care hours invested by parents or grandparents could have sized down the full impact that the pandemic would have had on the socio emotional development of the child. Increased time spent using electronic devices coupled with dwindled opportunities for interaction with peers have been notable challenges.

Progesterone receptor distribution in the human hypothalamus and its association with suicide

The human hypothalamus modulates mental health by balancing interactions between hormonal fluctuations and stress responses. Stress-induced progesterone release activates progesterone receptors (PR) in the human brain and triggers alterations in neuropeptides/neurotransmitters. As recent epidemiological studies have associated peripheral progesterone levels with suicide risks in humans, we mapped PR distribution in the human hypothalamus in relation to age and sex and characterized its (co-) expression in specific cell types. The infundibular nucleus (INF) appeared to be the primary hypothalamic structure via which progesterone modulates stress-related neural circuitry. An elevation of the number of pro-opiomelanocortin+ (POMC, an endogenous opioid precursor) neurons in the INF, which was due to a high proportion of POMC+ neurons that co-expressed PR, was related to suicide in patients with mood disorders (MD). MD donors who died of legal euthanasia were for the first time enrolled in a postmortem study to investigate the molecular signatures related to fatal suicidal ideations. They had a higher proportion of PR co-expressing POMC+ neurons than MD patients who died naturally. This indicates that the onset of endogenous opioid activation in MD with suicide tendency may be progesterone-associated. Our findings may have implications for users of progesterone-enriched contraceptives who also have MD and suicidal tendencies.

Subjective Health Status, Health-Related Behavior, and Health Literacy of Health Professional Students: Results from a Cross-Sectional Study.

The importance of health promotion for health professional students is increasingly crucial, as the rising requirements for those students can have a negative impact on their health. Despite this awareness, there is still limited knowledge in Germany about the specific health needs of this group of students. This study's aim was, therefore, to assess the subjective health of first-year students and to identify health needs. Thus, this study is based on an online survey using standardized measurement instruments. First-year students from three degree programs were included. The data were analyzed descriptively. A total of n = 98 (72.6%) participated in the survey. The results showed that a major proportion of participants (80.3%) rated their health positively, but a significant proportion reported weight disorders (24%) and pre-existing health conditions (62.1%) at baseline. Interestingly, a high proportion (59%) reported a high level of mental well-being at the time of the survey. However, worrying findings regarding lifestyle behaviors, including physical inactivity (40.6%), smoking (20%), risky alcohol use (24%), and unhealthy eating habits (37%) were determined. In terms of health literacy, around 45% of students rated their health competencies as problematic. Furthermore, it was found that students with low health literacy had a significantly higher prevalence of low mental well-being (53.3% vs. 30.8%, p = 0.036) and unhealthy eating habits (48.8% vs. 26.5%, p = 0.027) compared to students with sufficient health literacy. Health professional students should be considered a relevant target group for health and health competence promotion from the beginning of their studies. The identified fields of action should be addressed in the context of health promotion. This is of particular importance as they are not only aimed at improving the students' well-being but also will later work directly with patients and, therefore, have a direct influence on the health of others.

Analysis of risk factors and hypoxic-ischemic damage consequences to central nervous system in newborns

Perinatal damage to the central nervous system (CNS) is currently a pressing issue within the structure of neonatal pathology, leading to the development of various neurological complications and causing disability and death.The purpose. Identifying risk factors contributing to perinatal third-degree hypoxic-ischemic damage of the CNS in newborns and to examine the data of clinical, laboratory and instrumental studies.Results. In the course of this study, it was revealed that the leading syndromes at the birth of the majority of infants from the main group were the suppression syndrome and the syndrome of muscular hypotension. The highest proportion among extragenital pathologies was represented by infectious diseases of various etiologies, which the newborns’ mothers had suffered during pregnancy and childbirth. Most commonly reported pregnancy complications in mothers of the main group were anemia, fetal bladder abnormality and premature rupture of fetal membranes. Neurosonography revealed subependymal cysts, signs of cerebral ischemia and ventriculomegaly as most сommonly visualized abnormalities.Conclusions. It was established during the study that the primary risk factors for the development of hypoxic-ischemic damage to the CNS were complications during pregnancy and infectious diseases of various etiologies, which the mothers had suffered during pregnancy and childbirth.

Assessment of waste workers occupational risk to microbial agents and cytotoxic effects of mixed contaminants present in the air of waste truck cabin and ventilation filters

ABSTRACT Workers in the waste-processing industry are potentially exposed to high concentrations of biological contaminants, leading to respiratory and digestive problems and skin irritations. However, few data on the exposure of waste collection truck (WCT) drivers are available. The goal was to document the microbial risk of the waste collection truck (WCT) workers while in the vehicle cab. Long-period sampling using the truck air filters (CAF) and short time ambient air sampling in the cab were used. The potential release of microbial particles from CAFs was also investigated since it could contribute to the microbial load of the cabin air. A combination of analytical methods also helped assess the complex mixture of the biological agents. Aspergillus sections Fumigati and Flavi, E. coli, Enterobacter spp. and Legionella spp. were detected in the CAF of trucks collecting three types of waste. The highest levels of bacteria and fungi were found in the CAF from organic WCT. The highest endotoxin concentrations in CAF were 300 EU/cm2. Most of the CAF showed cytotoxic effects on both lung cells and hepatocytes. Only one mycotoxin was detected in a CAF. The maximal concentrations in the ambient WCT air varied according to the type of waste collected. The highest proportion (84%) of the air samples without cytotoxic effects on the lungs cells was for the recyclable material WCTs. The results revealed the potential microbial risk to workers from a complex mixture of bio-contaminants in the cabs of vehicles collecting all types of waste. The sustained cytotoxic effect indicates the potential adverse health-related impact of mixed contaminants (biological and non-biological) for the workers. Overall, this study highlights the benefits of using complementary sampling strategy and combined analytical methods for a the assessment of the microbial risk in work environments and the need to implement protective measures for the workers. Implications: Exposure to microbial agents is a well-known occupational hazard in the waste management sector. No previous study had evaluated the cytotoxicity of ambient air and ventilation filters to document worker exposure to a combination of contaminants during waste collection. This research confirms the usefulness of ventilation filters for long-term characterization of exposure to infectious agents, azole-resistant fungi, coliform bacteria and mycotoxin. Overall, this study highlights the importance of using several sampling and analysis methods for a comprehensive assessment of microbial risk in work environments, as well as the need to implement appropriate protective measures for collection workers.

MicroRNA Profiling of the Inflammatory Response after Early and Late Asthmatic Reaction.

A high proportion of house dust mite (HDM)-allergic asthmatics suffer from both an early asthmatic reaction (EAR) and a late asthmatic reaction (LAR) which follows it. In these patients, allergic inflammation is more relevant. MiRNAs have been shown to play an important role in the regulation of asthma's pathology. The aim of this study was to analyze the miRNA profile in patients with mild asthma and an HDM allergy after bronchial allergen provocation (BAP). Seventeen patients with EAR/no LAR and 17 patients with EAR plus LAR, determined by a significant fall in FEV1 after BAP, were differentially analyzed. As expected, patients with EAR plus LAR showed a more pronounced allergic inflammation and FEV1 delta drop after 24 h. NGS-miRNA analysis identified the down-regulation of miR-15a-5p, miR-15b-5p, and miR-374a-5p after BAP with the highest significance in patients with EAR plus LAR, which were negatively correlated with eNO and the maximum decrease in FEV1. These miRNAs have shared targets like CCND1, VEGFA, and GSK3B, which are known to be involved in airway remodeling, basement membrane thickening, and Extracellular Matrix deposition. NGS-profiling identified miRNAs involved in the inflammatory response after BAP with HDM extract, which might be useful to predict a LAR.

Disproportionate Rates of COVID-19 Among Black Canadian Communities: Lessons from a Cross-Sectional Study in the First Year of the Pandemic.

Racialized communities, including Black Canadians, have disproportionately higher COVID-19 cases. We examined the extent to which SARS-CoV-2 infection has affected the Black Canadian community and the factors associated with the infection. We conducted a cross-sectional survey in an area of Ontario (northwest Toronto/Peel Region) with a high proportion of Black residents along with 2 areas that have lower proportions of Black residents (Oakville and London, Ontario). SARS-CoV-2 IgG antibodies were determined using the EUROIMMUN assay. The study was conducted between August 15, 2020, and December 15, 2020. Among 387 evaluable subjects, the majority, 273 (70.5%), were enrolled from northwest Toronto and adjoining suburban areas of Peel, Ontario. The seropositivity values for Oakville and London were comparable (3.3% (2/60; 95% CI 0.4-11.5) and 3.9% (2/51; 95% CI 0.5-13.5), respectively). Relative to these areas, the seropositivity was higher for the northwest Toronto/Peel area at 12.1% (33/273), relative risk (RR) 3.35 (1.22-9.25). Persons 19 years of age or less had the highest seropositivity (10/50; 20.0%, 95% CI 10.3-33.7%), RR 2.27 (1.23-3.59). There was a trend for an interaction effect between race and location of residence as this relates to the relative risk of seropositivity. During the early phases of the pandemic, the seropositivity within a COVID-19 high-prevalence zone was threefold greater than lower prevalence areas of Ontario. Black individuals were among those with the highest seroprevalence of SARS-CoV-2.

Experimental study on the effects of chemical or microwave treatment on the tensile strength of hot dry rock

The Brazilian disc (BD) specimens were heated to high temperatures up to 100–500 °C followed by immersion in chemical solutions or irradiation in a microwave oven. The Brazilian splitting tests were then performed at high temperatures, and acoustic emission (AE) events were recorded. Meanwhile, the longitudinal wave velocity and open porosity of the rocks were measured, and the scanning electron microscope (SEM) was applied to identify the influence of chemical or microwave treatment on the microstructure in specimens. The experimental results show that: (1) the chemical or microwave treatment exacerbates the damage to the heat-treated rocks and that either treatment has significant effect on heat-treated rocks with diverse lithologies. (2) The specimens with a high proportion of soluble minerals are chemically dissolved and the specimens with a high percentage of powerful microwave absorption minerals were irradiated by the microwaves, resulting in lower longitudinal wave velocity, lower tensile strength, higher open porosity, and more severe microstructural damages. (3) Rock tensile strength is closely related to the breakdown pressure of hydraulic fracturing, implying that chemical or microwave-assisted fracturing techniques have significant impact on various hot dry rocks, and these auxiliary fracturing techniques considering rock lithology are novel and important for EGS projects.

Root-derived resources fuel earthworms predominantly via bacterial and plant energy channels – Insights from bulk and compound-specific isotope analyses

Soil food webs rely on both brown and green energy, i.e., litter material and root-derived resources such as exudates. Earthworms have traditionally been viewed as macro-detritivores fuelled by brown energy and playing a central role in nutrient cycling and belowground energy flux. However, the role of root-derived resources for earthworm nutrition remains controversial. We studied the dietary contribution of root-derived resources from different plant functional groups to earthworms using bulk and compound-specific stable isotope analyses in a microcosm experiment with five earthworm species, grasses and legumes in monoculture and mixture, and an unplanted control by preventing leaf litter from entering the microcosms. The presence of plants consistently depleted bulk 13C values of the five earthworm species studied suggesting that root-derived carbon contributed to earthworm nutrition in each of the species. The response of bulk 15N values was less consistent, which is in line with the assumption that root-derived resources fuel soil food webs mainly via carbon-based root exudates. These observations were corroborated by 13C values of essential amino acids suggesting that most of the tissue carbon of earthworms was incorporated via bacterial- (∼60%) and plant-derived resources (∼30%), with the presence of legumes enhancing the incorporation via plant-derived resources. The high proportion of bacterial resources in the earthworms was consistent with the relative dominance of bacteria in the experimental soil and suggests that bacteria serve as important link in the acquisition of food resources. However, it remains an open question whether earthworms feed directly on soil bacteria, bacterial residues in soil or rely on nutritional supplementation by gut microorganisms. Overall, our results show that when root-derived resources are available, earthworms, as macro-detritivores, also incorporate green energy, with these resources being assimilated mainly via the bacterial energy channel, pointing to the importance of bacterial energy channelling in ecosystems with high earthworm biomass.

Time to be blunt: Substance use in cystic fibrosis.

As the population of people with cystic fibrosis (pwCF) continues to age, attention is shifting towards addressing the unique challenges teenagers and adults face, including substance use. Changing attitudes and legality regarding marijuana and cannabidiol (CBD) may influence their use among pwCF, but data on the rate of use, reasons for use, and administration methods are lacking. Investigate marijuana, CBD, e-cigarette, and cigarette usage among pwCF and explore differences in demographics, disease severity, and cystic fibrosis transmembrane receptor (CFTR) modulator use between recent users and nonusers. This cross-sectional study used a one-time electronic survey to assess marijuana, CBD, e-cigarette, and cigarette use in pwCF aged >13 years. Demographic and clinical characteristics were compared between recent users and nonusers. The association between recent substance use and CFTR modulator use was analyzed using logistic regressions. Among 226 participants, 29% used marijuana, 22% used CBD, 27% used e-cigarettes, and 22% used cigarettes in the last 12 months. Users of all substances were more likely to be college-educated or aged 29-39 years than nonusers. E-cigarette users were 2.9 times more likely to use CFTR modulators (95% confidence interval [95% CI]: 0.98-11.00, p = .08) and marijuana users were 2.5 times more likely to use CFTR modulators compared to nonusers, adjusted for confounders. CBD, e-cigarettes, and cigarettes users were more likely to have an abnormal mental health screen compared to nonusers. A high proportion of never-users of marijuana and CBD expressed interest in using. Substance use is more prevalent among pwCF than previously reported and needs to be addressed by healthcare providers.

RESULTS OF TREATMENT FOR PAGET'S DISEASE OF THE BREAST AT THE NATIONAL CANCER HOSPITAL IN VIETNAM

Objectives: To describe the clinical and subclinical characteristics of patients with Paget's disease of the breast at The National Cancer Hospital and to evaluate the treatment outcomes of Paget's disease of the breast. Materials and methods: 46 patients were diagnosed and treated for Paget's disease of the breast in the Breast Surgery Department of The National Cancer Hospital from 2016 to 2020. Results: The average age was 60.6 ± 10.8. The common symptoms were nipple pain (76.1%) and nipple ulceration (65.2%). Paget's disease with invasive ductal carcinoma accounted for 37.0%, and Paget's disease with intraductal carcinoma accounted for 28.2%. The proportions of breast cancer stages 0, 1, 2, and 3 were 63.0%, 23.9%, 8.7%, and 4.4%, respectively. The proportions of total mastectomy and breast-conserving surgery were 97.8% and 2.2%, respectively. The 5-year overall survival and disease-free survival rates were 91.3% and 84.8%, respectively. Conclusions: A high proportion of Paget's disease of the breast cases are associated with underlying ductal carcinoma. Surgical treatment of Paget's disease has achieved positive outcomes in terms of overall survival and disease-free survival. Received 27 June 2023Revised 25 September 2023Accepted 28 November 2023

NanoSHP099-Targeted SHP2 Inhibition Boosts Ly6Clow Monocytes/Macrophages Differentiation to Accelerate Thrombolysis.

Tumor-associated thrombus (TAT) accounts for a high proportion of venous thromboembolism. Traditional thrombolysis and anticoagulation methods are not effective due to various complications and contraindications, which can easily lead to patients dying from TAT rather than the tumor itself. These clinical issues demonstrate the need to research diverse pathways for adjuvant thrombolysis in antitumor therapy. Previously, the phenotypic and functional transformation of monocytes/macrophages is widely reported to be involved in intratribal collagen regulation. This study finds that myeloid deficiency of the oncogene SHP2 sensitizes Ly6Clow monocyte/macrophage differentiation and can alleviate thrombus organization by increasing thrombolytic Matrix metalloproteinase (MMP) 2/9 activities. Moreover, pharmacologic inhibition by SHP099, examined in mouse lung metastatic tumor models, reduces tumor and thrombi burden in tumor metastatic lung tissues. Furthermore, SHP099 increases intrathrombus Ly6Clow monocyte/macrophage infiltration and exhibits thrombolytic function at high concentrations. To improve the thrombolytic effect of SHP099, NanoSHP099 is constructed to achieve the specific delivery of SHP099. NanoSHP099 is identified to be simultaneously enriched in tumor and thrombus foci, exerting dual tumor-suppression and thrombolysis effects. NanoSHP099 presents a superior thrombus dissolution effect than that of the same dosage of SHP099 because of the higher Ly6Clow monocyte/macrophage proportion and MMP2/MMP9 collagenolytic activities in organized thrombi.

Updated results of a phase 1b/2 study of surufatinib plus camrelizumab, nab-paclitaxel and S-1 (NASCA) as first-line therapy for metastatic pancreatic adenocarcinoma (mPDAC).

671 Background: This prospective, randomized controlled phase 1b/2 clinical study was designed to explore the efficacy and safety of surufatinib combined with camrelizumab, nab-paclitaxel and S-1 as first-line treatment compared with nab-paclitaxel and gemcitabine (AG) in mPDAC. Preliminary data was reported (Guanghai Dai, 2023 ASCO, 4142). Here we presented the updated data as more patients (pts) were recruited. Methods: In phase 1b, pts with mPDAC received surufatinib (200mg to 300mg, qd po), camrelizumab (200mg, I.V., D1, Q3W), nab-paclitaxel (125mg/m2, I.V., D1, D8, Q3W), and S-1 (40mg bid, D1-14, Q3W). Phase 2 is a prospective, open-label, randomized (1:1) trial comparing NASCA with AG in the first-line setting. The primary objective was the RP2D and overall response rate (ORR) per RECIST v1.1. Tumor tissue samples were collected at diagnosis and were subjected to mIHC to evaluate tumor immune microenvironment. Results: From Aug 2021 to Jun 2023, 49 pts were enrolled. As previously reported, 6 pts were enrolled in phase 1b and RP2D was determined as surufatinib 200mg. Of the 49 pts, 48 were evaluable for efficacy (28 in NASCA and 20 in AG group). ORR was 53.6% (15/28) (95% CI: 35.8-70.5) in pts receiving NASCA (pts in phase 1b included) and 15.0% (3/20) (95% CI: 5.2-36.0) in AG group. In NASCA group, pts with liver metastases exhibited higher ORR than those without liver metastases (71.4% vs 35.7%, p=0.13). Median progression-free survival and overall survival was 9.17m (95% CI: 5.5-NA) and 15.57m (95% CI: 9.27-NA) in NASCA group, 6.3m (95% CI: 4.87-NA) and 8.63m (95% CI: 7.90-NA) in AG group at the median follow-up of 13.7m. The most frequent adverse events (AEs) of all-grade in NASCA were neutropenia (57.1%), hepatotoxicity (42.9%), and neuropathy (39.3%). Immune-related AEs were observed in 5 pts with grade 3 hepatotoxicity in 4 pts and grade 2 enteritis in 1 pt. Safety was comparable in two groups except for hepatotoxicity and diarrhea. Using mIHC, the tissue of 13 pts treated with NASCA were stained for multiple markers of immune cells. CD3+ T cells infiltrated the tumor core at the highest level, followed by CD68+CD163- (M1) macrophages, and FOXP3+ T cells. Majority of immune cells and ICI biomarkers were expressed at higher proportion in the stroma. Pts with liver metastases displayed elevated tumoral FOXP3+ T cells (p=0.031), PD-L1+CD68+ macrophages (p=0.014), and decreased infiltration of stromal CD8+ T cells (p=0.064) than pts without liver metastases. In pts with liver metastases, responders displayed a higher stromal PD-1+ cells than nonresponders (p=0.036). Conclusions: Updated results proved that NASCA regimen presented higher clinical activity than the standard AG treatment, especially in pts with liver metastases, with a manageable safety profile. This trial is ongoing and NASCA regimen deserves further exploration in mPDAC. Clinical trial information: NCT05218889 .

Analysis The Impact and Mechanisms of Firms' ESG Performance on Their Financing Constraints--Evidence from Chinese Listed Companies

ESG performance is a significant non-financial measure used to assess a company's environmental, social responsibility, and corporate governance. Its influence on a company's financing constraints has increasingly become a research focus in the field of sustainable development and ecological civilization construction. This paper explores the impacts and mechanisms of ESG performance on firms' own financing constraints, and finds that: the enhancement of firms' ESG performance can alleviate their own financing constraints; firms' enhancement of ESG performance can alleviate their own financing constraints through the channel of improving the firms' information transparency; firms' enhancement of ESG performance can alleviate their financing constraints more strongly in the samples with a high proportion of the entire majority shareholders' holdings and those from the eastern part of China.

Research On Replenishment Decision of Vegetable Commodities Based on Seasonal Decomposition Exponential Smoothing Method and Objective Programming Model

Vegetables are indispensable in people’s daily lives and represent a high proportion of the goods sold in supermarkets and bring in a large amount of profit. Therefore, the replenishment and pricing decisions on the day of sales are particularly important. In order to make the best replenishment decision, this paper firstly solves the relationship equation between the sales volume of each vegetable category and the cost-plus ratio coefficient based on the least square fitting; secondly, considering the cyclical change of the vegetable sales volume, the seasonal decomposition of the exponential smoothing method is used to predict the demand for each vegetable category in the first week of July; lastly, the profitability optimization function of the superstore is set up: the objective function is the total profit of the superstore, and the decision variables are the daily supply of each vegetable category. The objective function is the total profit of the hypermarket, the decision variables are the daily supply of each vegetable category and the cost-plus ratio coefficient, and the constraints consider the maximum inventory of the hypermarket, the supply is greater than the demand and is less than the maximum value of the historical sales volume. The maximum daily profit and the optimal cost-plus ratio of the hypermarket are finally solved. This study has reference value for vegetable commodity replenishment decision.

Exploration and comparison of the relationship between PAHs and ROS in PM2.5 emitted from multiple anthropogenic sources in the Guanzhong Plain, China

Anthropogenic emissions have emerged as an important source of urban atmospheric PM2.5, exacerbating air pollution and the associated health implications. This study analyses PM2.5, originating from major anthropogenic sources (industries, motor vehicles, and solid-fuel combustion for domestic applications) in the Guanzhong Plain in China, along with the parent- (p-), alkylated- (a-), and oxygenated- (o-) polycyclic aromatic hydrocarbons (PAHs) and reactive oxygen species (ROS) levels in PM2.5. Industrial emissions are mainly characterised by high abundances of benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), and benz[a]fluoranthene (BaF). The 4-ring p-PAHs, such as fluoranthene (FLA), pyrene (PYR), benzo[a]anthracene (BaA), and chrysene (CHR) proportions and the diagnostic ratios of indeno[1,2,3-cd]pyrene (IcdP)/[IcdP + benzo[ghi]perylene (BghiP)] and 1-acenaphthenone (1ACO)/[1ACO + 9-fluorenone (9FO)] in motor vehicle emission PM2.5 were higher than the other sources. Household solid fuel combustion features high proportions of methylnaphthalene (M-NAP), i.e., 2 M-NAP and 1 M-NAP and 3-ring p-PAHs. Acenaphthylene (ACY), acenaphthene (ACE), anthracene (ANT), 1,4-chrysenequinone (1,4CHRQ), and reactive oxygen species (ROS) were positively correlated among the three anthropogenic sources. Moreover, the correlations between other PAHs and ROS varied significantly among the three sources. As mixed and compound organic pollutants, 2- and 3-ring p-PAHs were more positively correlated with the ROS activity of household solid fuel combustion sources compared with industrial and motor vehicle sources. Based on the relative contribution of these three sources to PAHs in PM2.5, we estimated the cancer risks of males and females in the Guanzhong area to be 2.95 × 10−6 and 2.87 × 10−6, respectively, exceeding the safety threshold of 1 × 10−6. This study provides a basic dataset for conducting a refined source apportionment of PM2.5 and a scientific basis for further understanding the relationship between PM2.5, PAHs, and ROS in northern China.

Moderate salinity and high ammonium/nitrate ratio enhance early growth in “summer wonder” lettuce cultivar

Because its impact in plant development and growth and its interaction with Na+ and Cl−, the supply of different N-forms to crops can be an easy-to-use tool with effective results on salinity tolerance. Here the effect of four N–NO3-/N–NH4+ ratios (mM; 2/0, 1.6/0.4, 0.4/1.6, 0/2) on adaptation to salt conditions (15 mM NaCl in a first experiment and 40 mM NaCl in a second experiment) was studied in young lettuce (cv “Summer wonder”) plants. The experiments were carried out in greenhouse and under hydroponics conditions. The results show that this cultivar tolerates and adapts to moderate salinity by deploying several structural and physiological mechanisms; (i) increasing allocation of biomass to the root, (ii) increasing root Na+ uptake and storing it in the shoot and root tissues, (iii) increasing intrinsic water use efficiency and (iv) increasing root N and P uptake. The beneficial effect of salt exposure on growth was greater when the predominant N-form was N–NO3-. These plants with higher tissue N–NO3- concentration, decreased Cl− uptake and shoot and root Cl− concentration. Regardless of salt conditions, plants with a high proportion of N–NH4+ (1.6 mM) and a low proportion of N–NO3- (0.4 mM) had a greater growth and nitrogen use efficiency, that was associated with the improved uptake of nutrients, and the maintenance of water status.

Change in the humus state of typical chernozem with various methods of tillage

Relevance. The article is devoted to the influence of various methods of tillage on the humus state of typical chernozem (Haplic Chernozems).Methods. Tillage options: plowing with a formation turnover (20–22 cm); combined processing (disking 8–10 cm + chisel 20–22 cm); surface treatment (disking) up to 8 cm; direct sowing. The object of the study was a typical powerful heavy loamy chernozem.Results. According to the results of the group and fractional composition of typical chernozem humus (regardless of the method of processing and the studied soil layer), the following patterns were established: the predominance of a group of humic acids (HA — 45–55% of organic carbon (Sorg.), a high proportion of humic acids associated with calcium (HA-2 — 29–41% of Sorg.), low content of non-hydrolyzable residue (NO — 29–36% of Sorg.), humate type of humus (Sgc:Sfk > 2), a very high degree of humification of organic matter (>4.5). With an increase in the depth of the arable layer (regardless of the method of tillage), there is an increase in Sgc, Sgc-2 and a decrease in carbon of humic acids free and associated with mobile oneand-a-half R2O3 (Sgc-1), carbon of humic acids associated with stable R2O3 (Sgc-3), and carbon of fulvic acids (Sfk). In the 0-20 cm layer, the predominance of Sgc-1 (5.5%) is noted, and their content decreases depending on the method of tillage in the series “combined (5.08%) → surface treatment → direct sowing (4.91)”. When applying an extreme degree of minimization (direct sowing) in a layer of 0–20 cm in relation to other methods of tillage, the largest amount of Sgk-2 is noted. The content of Sgk-3 and Sfk was highest with surface and combined treatment.

The association between clustering based on composition of volatile organic compound in indoor air and building-related symptoms

Volatile organic compounds (VOCs) have been suspected to cause building-related symptoms (BRSs). Although some studies investigated the association between BRSs and VOCs in indoor air, those results were inconsistent. This study investigated the contamination status of VOCs in the indoor air of 154 houses in Japan. Additionally, these samples were grouped by hierarchical clustering analysis based on the VOC composition, and the relationship between a VOC cluster and the BRSs was investigated. The median concentration of the sum of VOCs (ΣVOCs) was 140 μg m−3 (range: 18–3500 μg m−3). The levels of acetaldehyde in four samples and p-dichlorobenzene in one sample exceeded the guideline value. As a result of the hierarchical clustering analysis, the samples in this study were divided into six characteristic clusters based on the VOC composition. The ΣVOCs in cluster 1 were significantly lower than those in other clusters. In cluster 2, acyclic and aromatic hydrocarbons were dominant. Cluster 3 had a relatively high proportion of limonene. In cluster 4, the concentrations and composition ratios of α-pinene were higher than those of other clusters. In cluster 5, p-dichlorobenzene accounted for 42 %–72 % of the total VOCs. Cluster 6 had a relatively high proportion of decamethyl cyclopentasiloxane. This clustering likely depended on the construction of houses and lifestyles. As a result of logistic regression analysis, cluster 5 was associated with the cough symptoms of the BRSs. The results of the present study suggest that investigating the association between VOCs and BRSs is necessary to consider not only total concentrations such as TVOC and ΣVOCs but also VOC composition.

Optimizing the construction of ecological networks in Beijing using a morphological spatial pattern analysis—minimal cumulative resistance model

Introduction: With the increasing fragmentation of landscapes caused by rapid urbanisation, constructing ecological networks strengthen the connectivity between fragmented habitat patches. As the capital of China, Beijing has a rapid development, resulting in a serious landscape fragmentation, and needing an urgent demand for this study to improve the ecological network system.Methods: In this study, we choose the elevation, slope, Normalized Difference Vegetation Index and land use data of Beijing in 2020 as the data use. Morphological spatial pattern analysis (MSPA) was used to identify ecological source areas for Beijing, Minimal cumulative resistance (MCR) and gravity models were used to construct ecological network, and stepping stones to improve it.Results: The core area of Beijing had the highest proportion (96.17%) of all landscape types, forest accounting for 82.01% thereof. Ten core areas were identified as ecological source areas. Forty-five ecological corridors (8 major and 37 ordinary) were constructed. The ecological corridors are mainly concentrated in the middle and eastern regions where ecological mobility is limited. Constructing stepping stones would help uphold the region’s ecological service functions and ecosystem balance. Twenty-nine stepping stones and 32 ecological obstacles were used to create the optimised ecological network, consisting of 171.Discussion: The results provide an optimised ecological model for Beijing and a reference constructing ecological spatial networks for the sustainable development of ecological environments in high-density urban areas.