tert-Butyl Nitrite-Induced Radical Nitrile Oxidation Cycloaddition: Synthesis of Isoxazole/Isoxazoline-Fused Benzo 6/7/8-membered Oxacyclic Ketones.

A practical metal-free and additive-free approach for the synthesis of 6/7/8-membered oxacyclic ketone-fused isoxazoles/isoxazolines tetracyclic or tricyclic structures is reported through Csp3-H bond radical nitrile oxidation and the intramolecular cycloaddition of alkenyl/alkynyl-substituted aryl methyl ketones. This convenient approach enables the simultaneous formation of isoxazole/isoxazoline and 6/7/8-membered oxacyclic ketones to form polycyclic architectures by using tert-butyl nitrite (TBN) as a non-metallic radical initiator and N-O fragment donor.

Identification and Functional Analysis of Tomato CIPK Gene Family.

The calcineurin B-like interacting protein kinase (CIPK) protein family is a critical protein family in plant signaling pathways mediated by Ca2+, playing a pivotal role in plant stress response and growth. However, to the best of our knowledge, no study of the tomato CIPK gene family in response to abiotic stress has been reported. In this study, 22 members of the tomato CIPK gene family were successfully identified by using a combination of bioinformatics techniques and molecular analyses. The expression level of each member of tomato CIPK gene family under abiotic stress (low temperature, high salt, drought treatment) was determined by qRT-PCR. Results indicated that tomato CIPK demonstrated different degrees of responding to various abiotic stresses, and changes in SlCIPK1 and SlCIPK8 expression level were relatively apparent. The results of qRT-PCR showed that expression levels of SlCIPK1 increased significantly in early stages of cold stress, and the expression level of SlCIPK8 increased significantly during the three treatments at different time points, implicating Solanum lycopersicum CIPK1(SlCIPK1) and Solanum lycopersicum CIPK8 (SlCIPK8) involvement in abiotic stress response. SlCIPK1 and SlCIPK8 were silenced using Virus-induced gene silencing (VIGS), and physiological indexes were detected by low temperature, drought, and high salt treatment. The results showed that plants silenced by SlCIPK1 and SlCIPK8 at the later stage of cold stress were significantly less resistant to cold than wild-type plants. SlCIPK1 and SlCIPK8 silenced plants had poor drought resistance, indicating a relationship between SlCIPK1 and SlCIPK8 with response to low temperature and drought resistance. This is the first study to uncover the nucleotide sequence for tomato CIPK family members and systematically study the changes of tomato CIPK family members under abiotic stress. Here, we investigate the CIPK family's response under abiotic stress providing understanding into the signal transduction pathway. This study provides a theoretical basis for elucidating the function of tomato CIPK at low temperature and its molecular mechanism of regulating low temperatures.

Evaluation and prediction of carbon emission from logistics at city scale for low-carbon development strategy.

Low-carbon is a part of China's efforts to pursue the national strategy of "carbon peaking and carbon neutrality." Meanwhile, the path of low-carbon transformation of logistics has become a topic of global concern. This study constructs a technical framework of logistics carbon emissions (LCE), which is composed of carbon emission evaluation, carbon emission prediction and low-carbon strategy. All 13 prefecture-level cities in Jiangsu, China, are the application objects in empirical research. Then, the influence analysis of the LCE efficiency based on the panel Tobit model and the evolution of LCE under different scenarios are explored. The results show that: (ⅰ) during the study period (2013-2020), the LCE in Jiangsu showed an overall upward trend, with Xuzhou, Suzhou and Nanjing being the cities with the highest carbon emissions; (ⅱ) the static efficiency of LCE in Jiangsu is at a medium level, with fluctuations in Suzhou, Changzhou, Zhenjiang, Nantong, and Suqian caused by the technical change index; (ⅲ) economic level, industrial structure, fixed asset utilization rate, and ecological environment in Jiangsu are significantly positively correlated with LCE efficiency, while education popularization and energy intensity are negative; (ⅳ) LCE in Jiangsu has been drastically reduced in the low-carbon scenario compared to the baseline scenario. On the above basis, this study proposes suggestions for the low-carbon development strategies of logistics in Jiangsu.

Molecularly imprinted solid-phase extraction combined with non-ionic hydrophobic deep eutectic solvents dispersed liquid-liquid microextraction for efficient enrichment and determination of the estrogens in serum samples.

Hormonal drugs in biological samples are usually in low concentration and highly intrusive. It is of great significance to enhance the sensitivity and specificity of the detection process of hormone drugs in biological samples by utilizing appropriate sample pretreatment methods for the detection of hormone drugs. In this study, a sample pretreatment method was developed to effectively enrich estrogens in serum samples by combining molecularly imprinted solid-phase extraction, which has high specificity, and non-ionic hydrophobic deep eutectic solvent-dispersive liquid-liquid microextraction, which has a high enrichment ability. The theoretical basis for the effective enrichment of estrogens by non-ionic hydrophobic deep eutectic solvent was also computed by simulation. The results showed that the combination of molecularly imprinted solid-phase extraction and deep eutectic solvent-dispersive liquid-liquid microextraction could improve the sensitivity of HPLC by 33∼125 folds, and at the same time effectively reduce the interference. In addition, the non-ionic hydrophobic deep eutectic solvent has a relatively low solvation energy for estrogen and possesses a surface charge similar to that of estrogen, and thus can effectively enrich estrogen. The study provides ideas and methods for the extraction and determination of low-concentration drugs in biological samples and also provides a theoretical basis for the application of non-ionic hydrophobic deep eutectic solvent extraction.

Analysis of the spatio-temporal network of air pollution in the Yangtze River Delta urban agglomeration, China.

The complex correlation between regions caused by the externality of air pollution increases the difficulty of its governance. Therefore, analysis of the spatio-temporal network of air pollution (STN-AP) holds great significance for the cross-regional coordinated governance of air pollution. Although the spatio-temporal distribution of air pollution has been analyzed, the structural characteristics of the STN-AP still need to be clarified. The STN-AP in the Yangtze River Delta urban agglomeration (YRDUA) is constructed based on the improved gravity model and is visualized by UCINET with data from 2012 to 2019. Then, its overall-individual-clustering characteristics are analyzed through social network analysis (SNA) method. The results show that the STN-AP in the YRDUA was overall stable, and the correlation level gradually improved. The centrality of every individual city is different in the STN-AP, which reveals the different state of their interactive mechanism. The STN-AP could be subdivided into the receptive block, overflow block, bidirectional block and intermediary block. Shanghai, Suzhou, Hangzhou and Wuxi could be key cities with an all above degree centrality, betweenness centrality and closeness centrality and located in the overflow block of the STN-AP. This showed that these cities had a greater impact on the STN-AP and caused a more pronounced air pollution spillovers. The influencing factors of the spatial correlation of air pollution are further determined through the quadratic assignment procedure (QAP) method. Among all factors, geographical proximity has the strongest impact and deserves to be paid attention in order to prevent the cross-regional overflow of air pollution. Furthermore, several suggestions are proposed to promote coordinated governance of air pollution in the YRDUA.

Psychological Status of High School Students 1 Year After the COVID-19 Emergency.

Background: With the control of the epidemic, adolescents' mental outlook might have improved. However, little evidence existed with regard to the psychological status of adolescents in post-COVID-19 era. This present study aimed to explore the psychological status of high school students after the epidemic getting eased. Methods: A web-based cross-sectional survey was used to obtain data from three high schools, including the demographic information, the Patient Health Questionnaire-9 (PHQ-9), the Generalized Anxiety Disorder-7 (GAD-7), the Self-Rating Scale of Sleep (SRSS), and self-designed general recent-status questionnaire. Correlation analysis was performed to explore potential associations between the depression symptoms, anxiety symptoms, and sleep status. The PHQ-9 and GAD-7 differences between nowadays data and the data enrolled 12 months before were also compared. Result: A total of 1,108 qualified questionnaires were obtained. The prevalence of depressive and anxious symptoms was 27.5 and 21.3%, respectively, from mild to severe in all students, while 11.8% of these high students got sleep disturbances. Both the rate and the severity of depression, anxiety and sleep problems of female students were higher than male students. Grade three students suffered higher prevalence and severer mental disturbances than the other two grades. There were significant correlations between the depression symptoms, anxiety symptoms, and sleep status. The psychological status has been improved in nowadays high school students compared with the sample enrolled 12 months before. Conclusion: As a supplement to our former study, this present research provided a perspective on the psychological status of high school students 1 year after the COVID-19 pandemic being well controlled. We should pay attention to the psychological status of high school students, and should also notice the progresses made by this special group after the epidemic.

Prevalence of Depression and Anxiety Symptoms of High School Students in Shandong Province During the COVID-19 Epidemic.

Background: The coronavirus disease 2019 (covid-19) has brought physical risks as well as psychological challenges to the whole world. High school students are a special group suffering from both the academic pressure and the threat of the epidemic. The present study aims to conduct an online survey to investigate the psychological status of high school students in Shandong Province. Methods: Using a web-based cross-sectional survey, data was collected from 1,018 voluntary high school students assessed with demographic information, the Patient Health Questionnaire-9 (PHQ-9), the Generalized Anxiety Disorder-7 (GAD-7) and a self-designed online-study effect survey. Correlation analysis was performed to explore the relationships between depression symptoms, anxiety symptoms, and study effect. Result: The prevalence of depressive symptoms, anxiety symptoms, and a combination of depressive and anxiety symptoms was 52.4, 31.4, and 26.8%, respectively, among high school students in Shandong Province during the COVID-19 epidemic. And from moderate to severe severity level, the rates of depressive symptoms and anxious symptoms were 17.6 and 4.6%. Female students exhibited a higher rate and severity of mental symptoms than male, and grade one senior high school students got a higher rate and severity of mental symptoms than the other two grades. Nearly half of the students were not satisfied with their online-study effect. The PHQ-9 score had a strong positive correlation with the GAD-7 score. Both the PHQ-9 score the GAD-7 score had a negative correlation with the study-effect survey score. Conclusion: Quite a number of high school students suffered from depression and anxiety symptoms during the COVID-19 epidemic. Sufficient attentions should be paid, and necessary supports should be provided, to protect the mental health of this special group.

Trace analysis of glyclazide in human plasma at microscale level by mass spectrometry.

Green (reagents and organic solvents saving) analytical chemistry is a new strategy for pharmaceutical analysis. The principles of this idea include primary elimination or at least reduction of the amounts of organic reagents and solvents. In this study, we have provided two simple methods for the analysis of clinical drugs in human plasma. One is the capillary LC (Cap LC) connected to MS-MS, the other is the matrix-assisted laser desorption ionization (MALDI) connected to TOF MS. Sulfonylurea drugs are usually used in diabetes mellitus patients. Diabetes is a syndrome of disordered metabolism resulting in abnormally high blood sugar levels (hyperglycemia). These microscale methods were successfully applied for the monitoring of drug levels in human plasma using gliclazide (a second-generation sulfonylurea) as the test platform. The sensitivity of these methods is sufficient for detecting the gliclazide within a therapeutic range. All the analytical procedures (including human plasma, sample preparation, and flow rate of the analytical system) were at microscale level. These two methods would lower the consumption of organic solvents further safeguarding our environment.