[Determination of three new herbicide residues in soil, sediment and water by liquid chromatography-tandem mass spectrometry].

Herbicides play an important role in preventing and controlling weeds and harmful plants and are increasingly used in agriculture, forestry, landscaping, and other fields. However, the effective utilization rate of herbicides is only 20%-30%, and most herbicides enter the atmosphere, soil, sediment, and water environments through drift, leaching, and runoff after field application. Herbicide residues in the environment pose potential risks to ecological safety and human health. Therefore, establishing analytical methods to determine herbicide residues in environmental samples is of great importance. In this study, an analytical method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) in positive electrospray ionization mode (ESI+) was developed for the determination of isoxaflutole, metazachlor, and saflufenacil residues in soil, sediment, and water. The instrumental detection parameters, including electrospray ionization mode, mobile phase, and chromatographic column, were optimized. The mobile phases were methanol (A) and 0.1% formic acid aqueous solution (B). Gradient elution was performed as follows: 0-1.0 min, 60%A; 1.0-2.0 min, 60%A-90%A; 2.0-3.0 min, 90%A; 3.0-4.0 min, 90%A-60%A; 4.0-5.0 min, 60%A. The samples were salted after extraction with acetonitrile and cleaned using a C18 solid-phase extraction column. Different solid-phase extraction columns and leaching conditions were investigated during sample pretreatment. Working curves in the neat solvent and matrix were constructed by plotting the measured peak areas as a function of the concentrations of the analytes in the neat solvent and matrix. Good linearities were found for isoxaflutole, metazachlor, and saflufenacil in the solvent and matrix-matched standards in the range of 0.0005-0.02 mg/L, with r≥0.9961. The matrix effects of the three herbicides in soil, sediment, and water ranged from -10.1% to 16.5%. The limits of detection (LODs, S/N=3) for isoxaflutole, metazachlor, and saflufenacil were 0.05, 0.01, and 0.02 µg/kg, respectively. The limits of quantification (LOQs, S/N=10) for isoxaflutole, metazachlor, and saflufenacil were 0.2, 0.05, and 0.05 µg/kg, respectively. The herbicides were applied to soil, sediment, and water at spiked levels of 0.005, 0.1, and 2.0 mg/kg, respectively. The average recoveries for isoxaflutole, metazachlor, and saflufenacil in soil, sediment, and water were in the ranges of 77.2%-101.9%, 77.9%-105.1%, and 80.8%-107.1%, respectively. The RSDs for isoxaflutole, metazachlor, and saflufenacil were in the ranges of 1.4%-12.8%, 1.2%-7.7%, and 1.5%-11.5%, respectively. The established method was used to analyze actual samples collected from four different sites in Zhejiang Province (Xiaoshan, Taizhou, Dongyang, and Yuhang) and one site in Heilongjiang (Jiamusi). The proposed method is simple, rapid, accurate, stable, and highly practical. It can be used to detect isoxaflutole, metazachlor, and saflufenacil residues in soil, sediment, and water and provides a reference for monitoring the residual pollution and environmental behavior of herbicides.

Paediatric oncology ward nurses' experiences of patients' deaths in China: A qualitative study.

BACKGROUND: Considering cancer death is second only to accidental death in the number of lives claimed each year,nurses in paediatric oncology wards often experience helplessness, sadness, frustration and such other adverse emotions when they witness children's death due to cancer.However,there is a lack of qualitative studies on nurses who witness the death of children in paediatric oncology wards in China. METHOD: A qualitative study was conducted using a semi-structured interview guide with 22 paediatric oncology ward nurses. Interviews were recorded and simultaneously translated and transcribed. Thematic analysis was used to analyse the data. RESULTS: The analysis resulted in the identification of three main thematic categories: Different emotional expression, Different copingstrategies, A weak support system. Nursing managers should pay attention to problems faced by nurses in paediatric oncology wards, and take targeted measures in terms of continuing training courses, improving the psychological adaptability of oncology professional nurses, and providing them substantive support. CONCLUSION: Nurses in paediatric oncology wards have strong stress responses to facing the death of children. They reported experiencing complex psychological feelings and have different coping attitudes. Healthcare authorities should recognise and understand the needs of paediatric oncology ward nurses, who often witness the death of children. Appropriate and effective support measures should be planned and implemented for these nurses to maintain their mental health, thus enabling them to better serve patients.

Relationship of Physical Activity With Anxiety and Depression Symptoms in Chinese College Students During the COVID-19 Outbreak.

INTRODUCTION: During the COVID-19 outbreak, many citizens were asked to stay at home in self-quarantine, which can pose a significant challenge with respect to remaining physically active and maintaining mental health. This study aimed to evaluate the prevalence of inadequate physical activity, anxiety, and depression and to explore the relationship of physical activity with anxiety and depression symptoms among Chinese college students during quarantine. METHOD: Using a web-based cross-sectional survey, we collected data from 1,396 Chinese college students. Anxiety and depression were assessed with the Self-Rating Anxiety Scale (SAS) and the Self-Rating Depression Scale (SDS), respectively. The data on physical activity were collected by types of physical activity and the International Physical Activity Questionnaire (IPAQ-SF). RESULTS: During the COVID-19 outbreak, about 52.3% of Chinese college students had inadequate physical activity. The rates of anxiety and depression symptoms were 31.0 and 41.8%, respectively. A high level of physical activity (ß = -0.121, P < 0.001) was significantly closely associated with low anxiety, while a moderate (ß = -0.095, P = 0.001), or high (ß = -0.179, P < 0.001) level of physical activity was significantly closely associated with reduced depression after adjusting confounding demographic factors. Moreover, specific types of physical activity, such as stretching and resistance training, were negatively correlated with both anxiety and depression; doing household chores was negatively correlated with depression. CONCLUSION: Our findings highlight specific levels and types of home-based physical activities that need to be taken into consideration to protect the mental health of college students during the COVID-19 epidemic.

Screening pathways and hub genes involved in osteoclastogenesis by gene expression analysis of circulating monocytes based on Gibbs sampling.

Differential expression pathways and hub genes in circulating monocytes from healthy Chinese women with high peak bone mass (PBM) vs. low PBM were explored using a Markov chain Monte Carlo (MCMC) algorithm. Human circulating monocytes transcription profiling (containing 14 samples with high PBM and 12 samples with low PBM) and KEGG pathways were all downloaded from the public database. Initial state of all the pathways were constructed and Gibbs sampling was performed to obtain a Markov chain and the posterior values of all the pathways were calculated. The probability (α) of occurrence of each pathway was calculated based on the posterior value and it was adjusted by taking gene expression variation into account. Pathways with αadj >0.8 were considered as differentially expressed pathways. Then, these steps were performed again on all the genes in the differentially expressed pathways to find the hub genes in the differential pathways. After Gibbs sampling, neuroactive ligand-receptor interaction (hsa04080) with αadj = 0.986 was screened out as the differentially expressed pathway. Analyzing the genes in this pathway, three genes (neurotensin, tachykinin receptor 3 and follicle-stimulating hormone receptor) with αadj >0.8 were identified as hub genes in circulating monocytes which may associate with osteoporosis development. One pathway and three genes which may possess close relationship with osteoporosis development were found in this study. These results provide insights into our understanding of the role of circulating monocytes in osteoporosis development.

Diabetic ketoacidosis in pregnancy tends to occur at lower blood glucose levels: case-control study and a case report of euglycemic diabetic ketoacidosis in pregnancy.

BACKGROUND AND OBJECTIVE: The occurrence of diabetic ketoacidosis (DKA) during pregnancy is considered a medical emergency. The aims of the present study were to evaluate the incidence of DKA in pregnant and non-pregnant women with diabetes; to compare the blood glucose levels at the diagnosis of DKA in pregnant and non-pregnant women; and to show a case of euglycemic DKA in pregnancy. METHODS: The subjects consisted of 90 cases of DKA in pregnant women with diabetes and 286 cases of non-pregnant female inpatients receiving treatment for diabetes during 2001 to 2005 in our hospital. The incidence of DKA in pregnant and non-pregnant women with diabetes and the blood glucose levels at the diagnosis of DKA in pregnant and non-pregnant women were compared. RESULTS: DKA had a higher incidence in pregnant women with diabetes (8/90, 8.9%) than in non-pregnant women with diabetes (9/286, 3.1%) (P < 0.05). The blood glucose levels (mmol/L) in pregnant women with DKA were significantly lower than those in non-pregnant women with DKA (16.3 +/- 4.6 vs 27.5 +/- 4.8, P < 0.001). A case of euglycemic DKA in pregnancy was described whose serum glucose level was only 6.9 mmol/L. CONCLUSIONS: DKA in pregnant women with diabetes may occur more frequently, and at lower blood glucose levels than DKA in non-pregnant women with diabetes.