Synthesis of medium-sized heterocycles from oxetanes based on an allylic amination/ring-opening strategy.

The construction of medium-sized ring compounds has been a prominent research area in synthetic chemistry. In this study, we developed a tandem strategy that combines allylic amination and ring-opening of oxetanes to synthesize medium-sized heterocycles. Specifically, N-aryl oxetan-3-amines undergo allylic amination with zwitterionic π-allylpalladium, followed by intramolecular ring-opening, resulting in the formation of medium-sized heterocycles. Notably, we are able to achieve the synthesis of 7-8 membered heterocycles with moderate to good yields by employing different types of zwitterionic π-allylpalladium species.

Pd-Catalyzed Ligand-Directed Divergent Cycloaddition of Cyclic 1-Azadienes with Oxo-1,4-dipoles.

Ligand-directed divergent synthesis (LDS) is an important synthetic tool for the preparation of structurally diverse organic molecules without tedious steps to modify substrates. Herein, we introduce the realization of 3,4-, 1,2-, and 1,4-cyclization of benzo[d]isothiazole-1,1-dioxide-fused azadienes (BDAs) through LDS, leading to tetrahydro-2H-pyrans, oxazinanes, and tetrahydro-2H-1,5-oxazocines, respectively. Using phosphinooxazoline (PHOX) ligands, we have developed a [4 + 2] cycloaddition between BDAs and substituted 2-alkylidenetrimethylene carbonates, providing access to multi-substituted chiral tetrahydro-2H-pyrans in good yields with excellent enantio-, diastereo-, and regioselectivities.

Automatic reconstruction of interstitial needles using CT images in post-operative cervical cancer brachytherapy based on deep learning.

Purpose: The purpose of this study was to investigate the precision of deep learning (DL)-based auto-reconstruction in localizing interstitial needles in post-operative cervical cancer brachytherapy (BT) using three-dimensional (3D) computed tomography (CT) images. Material and methods: A convolutional neural network (CNN) was developed and presented for automatic reconstruction of interstitial needles. Data of 70 post-operative cervical cancer patients who received CT-based BT were used to train and test this DL model. All patients were treated with three metallic needles. Dice similarity coefficient (DSC), 95% Hausdorff distance (95% HD), and Jaccard coefficient (JC) were applied to evaluate the geometric accuracy of auto-reconstruction for each needle. Dose-volume indexes (DVI) between manual and automatic methods were used to analyze the dosimetric difference. Correlation between geometric metrics and dosimetric difference was evaluated using Spearman correlation analysis. Results: The mean DSC values of DL-based model were 0.88, 0.89, and 0.90 for three metallic needles. Wilcoxon signed-rank test indicated no significant dosimetric differences in all BT planning structures between manual and automatic reconstruction methods (p > 0.05). Spearman correlation analysis demonstrated weak link between geometric metrics and dosimetry differences. Conclusions: DL-based reconstruction method can be used to precisely localize the interstitial needles in 3D-CT images. The proposed automatic approach could improve the consistency of treatment planning for post-operative cervical cancer brachytherapy.

Visible-light-induced organocatalytic enantioselective N-H insertion of α-diazoesters enabled by indirect free carbene capture.

While asymmetric insertion of metal carbenes into H-X (X = C, N, O, etc.) bonds has been well-established, asymmetric control over free carbenes is challenging due to the presence of strong background reactions and lack of any anchor for a catalyst interaction. Here we have achieved the first photo-induced metal-free asymmetric H-X bond insertion of this type. With visible light used as a promoter and a chiral phosphoric acid used as a catalyst, α-diazoesters and aryl amines underwent smooth N-H bond insertion to form enantioenriched α-aminoesters with high efficiency and good enantioselectivity under mild conditions. Key to the success was the use of DMSO as an additive, which served to rapidly capture the highly reactive free carbene intermediate to form a domesticated sulfoxonium ylide.

Evaluation of auto-segmentation for brachytherapy of postoperative cervical cancer using deep learning-based workflow.

Objective. The purpose of this study was to evaluate the accuracy of brachytherapy (BT) planning structures derived from Deep learning (DL) based auto-segmentation compared with standard manual delineation for postoperative cervical cancer.Approach. We introduced a convolutional neural networks (CNN) which was developed and presented for auto-segmentation in cervical cancer radiotherapy. The dataset of 60 patients received BT of postoperative cervical cancer was used to train and test this model for delineation of high-risk clinical target volume (HRCTV) and organs at risk (OARs). Dice similarity coefficient (DSC), 95% Hausdorff distance (95%HD), Jaccard coefficient (JC) and dose-volume index (DVI) were used to evaluate the accuracy. The correlation between geometric metrics and dosimetric difference was performed by Spearman's correlation analysis. The radiation oncologists scored the auto-segmented contours by rating the lever of satisfaction (no edits, minor edits, major edits).Main results. The mean DSC values of DL based model were 0.87, 0.94, 0.86, 0.79 and 0.92 for HRCTV, bladder, rectum, sigmoid and small intestine, respectively. The Bland-Altman test obtained dose agreement for HRCTV_D90%, HRCTV_Dmean, bladder_D2cc, sigmoid_D2ccand small intestine_D2cc. Wilcoxon's signed-rank test indicated significant dosimetric differences in bladder_D0.1cc, rectum_D0.1ccand rectum_D2cc(P< 0.05). A strong correlation between HRCTV_D90%with its DSC (R= -0.842,P= 0.002) and JC (R= -0.818,P= 0.004) were found in Spearman's correlation analysis. From the physician review, 80% of HRCTVs and 72.5% of OARs in the test dataset were shown satisfaction (no edits).Significance. The proposed DL based model achieved a satisfied agreement between the auto-segmented and manually defined contours of HRCTV and OARs, although the clinical acceptance of small volume dose of OARs around the target was a concern. DL based auto-segmentation was an essential component in cervical cancer workflow which would generate the accurate contouring.

Construction of diverse polycyclic N-heterocycles via cascade allylic amination/Diels-Alder reaction.

An efficient cascade approach for the construction of nitrogen-containing polycyclic compounds from amines tethered with an alkenyl (or alkynyl) group and divinyl carbonates is described. In the presence of Pd(0)-catalyst, an active zwitterionic allylpalladium species is generated and undergoes allylic amination with various amines followed by Diels-Alder reaction to form various polycyclic N-heterocyclic products, including hydrophenanthridines, hydrobenzo[c]azepines (hydro)isoindoles and hydrobenzo[cd]indoles.

Construction of nine-membered N,N,O-heterocycles via Pd-catalyzed [6+3] dipolar cycloaddition.

A new approach for the synthesis of 9-membered N,N,O-heterocycles by Pd-catalyzed [6+3] dipolar cycloaddition of N-iminoisoquinolinium ylides and 2-vinyl oxetanes has been developed. The scope of this cycloaddition was demonstrated with 28 examples. This is another important synthetic strategy for medium-sized rings by employing N-iminoisoquinolinium ylides as ternary synthons.

Evaluation of auto-segmentation for EBRT planning structures using deep learning-based workflow on cervical cancer.

Deep learning (DL) based approach aims to construct a full workflow solution for cervical cancer with external beam radiation therapy (EBRT) and brachytherapy (BT). The purpose of this study was to evaluate the accuracy of EBRT planning structures derived from DL based auto-segmentation compared with standard manual delineation. Auto-segmentation model based on convolutional neural networks (CNN) was developed to delineate clinical target volumes (CTVs) and organs at risk (OARs) in cervical cancer radiotherapy. A total of 300 retrospective patients from multiple cancer centers were used to train and validate the model, and 75 independent cases were selected as testing data. The accuracy of auto-segmented contours were evaluated using geometric and dosimetric metrics including dice similarity coefficient (DSC), 95% hausdorff distance (95%HD), jaccard coefficient (JC) and dose-volume index (DVI). The correlation between geometric metrics and dosimetric difference was performed by Spearman's correlation analysis. The right and left kidney, bladder, right and left femoral head showed superior geometric accuracy (DSC: 0.88-0.93; 95%HD: 1.03 mm-2.96 mm; JC: 0.78-0.88), and the Bland-Altman test obtained dose agreement for these contours (P > 0.05) between manual and DL based methods. Wilcoxon's signed-rank test indicated significant dosimetric differences in CTV, spinal cord and pelvic bone (P < 0.001). A strong correlation between the mean dose of pelvic bone and its 95%HD (R = 0.843, P < 0.001) was found in Spearman's correlation analysis, and the remaining structures showed weak link between dosimetric difference and all of geometric metrics. Our auto-segmentation achieved a satisfied agreement for most EBRT planning structures, although the clinical acceptance of CTV was a concern. DL based auto-segmentation was an essential component in cervical cancer workflow which would generate the accurate contouring.

Correlates of Early Adolescents' Social Media Engagement: The Role of Pubertal Status and Social Goals.

Specific social media behaviors have been found to be differentially associated with adjustment outcomes; however, the extant research has yet to consider the motivations behind why adolescents engage in these specific behaviors. This study examined the role of two developmentally relevant motivational correlates (social goals and pubertal status) on four social media behaviors (self-disclosure, self-presentation, social monitoring, and lurking) and two time-based measures of social media use (daily number of hours on social media and frequency of social media use). Self-report data were collected from 426 middle-school students (54.2% female, 73.6% White, 11.5% Black, 4.8% Hispanic, 10.1% other ethnicity, and mean age = 12.91). Social goals and pubertal status were distinctly associated with different social media behaviors, with some relevant sex differences. Popularity goal was positively associated with all six measures of social media engagement, although the associations for self-presentation and social monitoring were stronger for girls. Sex differences in lurking followed the same pattern but did not reach significance. Acceptance goal was associated with fewer hours spent on social media for girls only. Early developers reported more self-disclosure and lurking behaviors, and marginally more social monitoring (girls only). These findings indicate the importance of identifying motivational factors, especially social goals, when considering early adolescents' social media behaviors.

Mild Intermolecular Synthesis of a Cyclopropane-Containing Tricyclic Skeleton: Unusual Reactivity of Isobenzopyryliums.

Cyclopropanes embedded in a polycyclic bridged architecture are a versatile structural motif, but such complex frameworks often impose substantial synthetic challenges. Herein we introduce a new approach for the expedient access to such spring-loaded strained systems via an exceptionally mild intermolecular convergent process between the readily available isobenzopyryliums and vinyl boronic acids. Different from the typical conventional approaches, our protocol does not involve the highly active carbenoid intermediates or strong conditions in order to overcome the disfavored kinetic and thermodynamic problems. Instead, the key cyclopropane ring was formed between the well-positioned nucleophile and electrophile in the adduct from the regioselective [4+2] cycloaddition. Thus, this unusual process also represents a new reactivity of the versatile isobenzopyryliums. The choice of a Brønsted acid catalyst with proper acidity is crucial to the high efficiency and selectivity for this multiple bond-forming process. The strained products are precursors to other useful synthetic building blocks.

Adjustment Correlates of Social Media Engagement Among Early Adolescents.

Social media engagement is common among adolescents, yet not all adolescents use social media in the same ways or experience the same adjustment correlates. This study examined four social media behaviors (self-disclosure, self-presentation, lurking, and social monitoring) and two time-based measures of social media use (daily number of hours on social media and frequency of social media use) on three developmentally relevant adjustment correlates (internalizing problems, prosocial support, and online peer victimization). Self-report data were collected from 426 middle-school students (54.2% female, 73.6% Caucasian, 11.5% Black, 4.8% Hispanic, 10.1% other ethnicity, mean age = 12.91). The findings showed distinct adjustment patterns among the social media engagement indices, as well as sex and age differences. Neither the number of hours on social media nor social monitoring were associated with any adjustment correlates; however, the frequency of social media use was associated with positive adjustment (less internalizing problems and more prosocial support), primarily for older adolescents. Self-disclosure was positively associated with online peer victimization (girls only) and prosocial support. Self-presentation was associated with higher levels of internalizing problems and online peer victimization, as well as less prosocial support for younger adolescents and boys. Lurking was positively associated with internalizing problems. The findings suggest the need to consider specific types of social media engagement when creating prevention and intervention programs to address adolescent maladjustment.

Peer-Related Factors as Moderators between Overt and Social Victimization and Adjustment Outcomes in Early Adolescence.

Peer victimization is a pervasive problem for early adolescents, yet not all victims experience the same adjustment difficulties. The prominence of peer social relationships during adolescence suggests that peer-related factors (e.g., peer support) may be important for victim outcomes. This study investigated the moderating effects of three peer-related factors (peer support, peer preference, and social status) on the association between peer victimization (overt and social) and adjustment outcomes (loneliness and aggression) using a longitudinal design. Self-report and peer nomination data were collected from 321 participants from three middle schools in the Northeastern United States during the fall and spring of seventh grade (Mage = 13.01; 49% African American, 31% White, 19% Hispanic). The findings suggest that peer-related factors contribute to victim outcomes. Both forms of victimization were positively associated with loneliness under high peer preference and were negatively associated with aggression under low peer preference. Sex differences were also noted. Overt victimization was associated with decreased aggression only among girls under low peer preference, low peer support, or high social status. The findings suggest that parents, school officials, and mental health professionals should consider peer-related factors in providing support for victims, especially female victims.

[A clinical epidemiological investigation of neonatal acute respiratory distress syndrome in southwest Hubei, China].

OBJECTIVE: To investigate the clinical features and outcome of neonatal acute respiratory distress syndrome (ARDS) in southwest Hubei, China. METHODS: According to the Montreux definition of neonatal ARDS, a retrospective clinical epidemiological investigation was performed on the medical data of neonates with ARDS who were admitted to Department of Neonatology/Pediatrics in 17 level 2 or level 3 hospitals in southwest Hubei from January to December, 2017. RESULTS: A total of 7 150 neonates were admitted to the 17 hospitals in southwest Hubei during 2017 and 66 (0.92%) were diagnosed with ARDS. Among the 66 neonates with ARDS, 23 (35%) had mild ARDS, 28 (42%) had moderate ARDS, and 15 (23%) had severe ARDS. The main primary diseases for neonatal ARDS were perinatal asphyxia in 23 neonates (35%), pneumonia in 18 neonates (27%), sepsis in 12 neonates (18%), and meconium aspiration syndrome in 10 neonates (15%). Among the 66 neonates with ARDS, 10 neonates (15%) were born to the mothers with an age of ≥35 years, 30 neonates (45%) suffered from intrauterine distress, 32 neonates (49%) had a 1-minute Apgar score of 0 to 7 points, 24 neonates (36%) had abnormal fetal heart monitoring results, and 21 neonates (32%) experienced meconium staining of amniotic fluid. Intraventricular hemorrhage was the most common comorbidity (12 neonates), followed by neonatal shock (9 neonates) and patent ductus arteriosus (8 neonates). All 66 neonates with ARDS were treated with mechanical ventilation in addition to the treatment for primary diseases. Among the 66 neonates with ARDS, 10 died, with a mortality rate of 15% (10/66), and 56 neonates were improved or cured, with a survival rate of 85% (56/66). CONCLUSIONS: Neonatal ARDS in southwest Hubei is mostly mild or moderate. Perinatal asphyxia and infection may be the main causes of neonatal ARDS in this area. Intraventricular hemorrhage is the most common comorbidity. Neonates with ARDS tend to have a high survival rate after multimodality treatment.

Investigation of the Psychological disorders in the healthcare nurses during a coronavirus disease 2019 outbreak in China.

The first case of atypical pneumonia caused by coronavirus disease 2019 (COVID-19) was reported in Wuhan, China in December 2019. Since then, cases of novel coronavirus-infected pneumonia (NCIP) have been reported throughout China as well as in 25 other countries. With the rapid growth of this global outbreak, psychological disorders or impact among the healthcare nurses caused by the COVID-19 pandemic is of great importance and worth to be evaluated. Here, we aimed to determine the levels of stress and psychological disorders of nurses who provided nursing care during the COVID-19 outbreak. A total of 159 nurses who provided healthcare work for COVID-19 patients were enrolled in our study. The psychological disorders and stress level were assessed via a questionnaire implemented by the mobile app. The results showed that the nurses who worked in the non-critical care ward (general ward in which the invasive medical procedure such as mechanical ventilation is absent) scored significantly higher on the traumatization condition (P < .05) and stress level (P < .01) as well as the impact of event scale -revised level (P < .01) compared with those worked in the critical care ward. In contrast to the previous report, our findings revealed that the future intervention for preventing the mental crisis among the healthcare nurses needs to be focusing on the individuals in the non-critical care ward instead of those in the critical care ward under the spreading of COVID-19.

[Incidence of neonatal asphyxia and contributing factors for the develpment of severe asphyxia in Hubei Enshi Tujia and Miao Autonomous Prefecture: a multicenter study].

OBJECTIVE: To investigate the incidence of neonatal asphyxia and possible contributing factors for the development of severe asphyxia in Hubei Enshi Tujia and Miao Autonomous Prefecture, China. METHODS: A total of 16 hospitals in Hubei Enshi Tujia and Miao Autonomous Prefecture were selected as research centers. A retrospective analysis was performed for the clinical data of 22 294 live births in these 16 hospitals from January to December, 2016 to investigate the incidence rate of neonatal asphyxia and possible contributing factors for the development of severe asphyxia. RESULTS: Of the 22 294 neonates born alive, 733 (3.29%) were diagnosed with neonatal asphyxia, among whom 627 had mild asphyxia and 106 had severe asphyxia. The neonates with low maternal education level, maternal anemia during pregnancy, chorioamnionitis, abnormal amniotic fluid, abnormal umbilical cord, placenta previa, placental abruption, Tujia Minority, preterm birth, and low birth weight had a higher incidence of severe asphyxia (P<0.05). CONCLUSIONS: The incidence rate of neonatal asphyxia in Hubei Enshi Tujia and Miao Autonomous Prefecture is higher. Low maternal education level, maternal anemia during pregnancy, chorioamnionitis, abnormal amniotic fluid, abnormal umbilical cord, placenta previa, placental abruption, Tujia Minority, preterm birth, and low birth weight may be related to the development of severe neonatal asphyxia.

Revealing radiotherapy- and chemoradiation-induced pathway dynamics in glioblastoma by analyzing multiple differential networks.

The progression of glioblastoma (GBM) is driven by dynamic alterations in the activity and connectivity of gene pathways. Revealing these dynamic events is necessary in order to understand the pathological mechanisms of, and develop effective treatments for, GBM. The present study aimed to investigate dynamic alterations in pathway activity and connectivity across radiotherapy and chemoradiation conditions in GBM, and to give system­level insights into molecular mechanisms for GBM therapy. A total of two differential co­expression networks (DCNs) were constructed using Pearson correlation coefficient analysis and one sided t­tests, based on gene expression profiles and protein­protein interaction networks, one for each condition. Subsequently, shared differential modules across DCNs were detected via significance analysis for candidate modules, which were obtained according to seed selection, module search by seed expansion and refinement of searched modules. As condition­specific differential modules mediate differential biological processes, the module connectivity dynamic score (MCDS) was implemented to explore dynamic alterations among them. Based on DCNs with 287 nodes and 1,052 edges, a total of 28 seed genes and seven candidate modules were identified. Following significance analysis, five shared differential modules were identified in total. Dynamic alterations among these differential modules were identified using the MCDS, and one module with significant dynamic alterations was identified, termed the dynamic module. The present study revealed the dynamic alterations of shared differential modules, identified one dynamic module between the radiotherapy and chemoradiation conditions, and demonstrated that pathway dynamics may applied to the study of the pathogenesis and therapy of GBM.

Understanding social hierarchies: The neural and psychological foundations of status perception.

Social groups across species rapidly self-organize into hierarchies, where members vary in their level of power, influence, skill, or dominance. In this review, we explore the nature of social hierarchies and the traits associated with status in both humans and nonhuman primates, and how status varies across development in humans. Our review finds that we can rapidly identify social status based on a wide range of cues. Like monkeys, we tend to use certain cues, like physical strength, to make status judgments, although layered on top of these more primitive perceptual cues are sociocultural status cues like job titles and educational attainment. One's relative status has profound effects on attention, memory, and social interactions, as well as health and wellness. These effects can be particularly pernicious in children and adolescents. Developmental research on peer groups and social exclusion suggests teenagers may be particularly sensitive to social status information, but research focused specifically on status processing and associated brain areas is very limited. Recent evidence from neuroscience suggests that there may be an underlying neural network, including regions involved in executive, emotional, and reward processing, that is sensitive to status information. We conclude with questions for future research as well as stressing the need to expand social neuroscience research on status processing to adolescents.

Moderating effects of group status, cohesion, and ethnic composition on socialization of aggression in children's peer groups.

We explored the effects of 3 group features (i.e., status, cohesion, and ethnic composition) on socialization processes of aggression in early adolescents' natural peer social groups. Gender differences in these effects were also determined. A total of 245 seventh-grade individuals belonging to 65 peer groups were included in the analyses. All 3 group features moderated the strength of group socialization on physical aggression with the exception of group status on girls' physical aggression. Stronger socialization of physical aggression occurred in higher status, more cohesive, or ethnically more homogeneous groups. In contrast, only group cohesion moderated the strength of group socialization on social aggression among girls. These findings suggest that somewhat different processes may be involved in peer group influences on different forms of aggression. Future intervention and prevention efforts for adolescent aggression should consider peer group membership and group features simultaneously.

The role of popularity goal in early adolescents' behaviors and popularity status.

The effect of popularity goal on the use of 3 popularity-related behaviors and later popularity status was examined in a diverse sample of 314 6th-grade students (176 girls and 138 boys) in both fall (Time 1) and spring (Time 2) semesters. Popularity goal and the use of popularity-driven behaviors (e.g., "I change the way I dress in order to be more popular") were assessed by self-report survey items (Time 1). Physical aggression, social aggression (Time 1), and perceived popularity (Times 1 and 2) were assessed by peer nominations. Popularity goal was positively associated with popularity-driven behaviors, social aggression, and physical aggression. There was a significant interaction effect between popularity goal and popularity status on the use of concurrent social aggression at Time 1; a higher popularity goal was associated with greater usage of social aggression for high-popular adolescents. Popularity goal alone did not predict popularity status change at Time 2; rather, greater use of social aggression at Time 1 was associated with higher Time 2 popularity status for initially high-popular adolescents who had a high-popularity goal and for initially low-popular adolescents who had a low-popularity goal. A similar 3-way interaction effect was found for physical aggression. Results suggest that the adolescents' goal for popularity may help us better understand the functions of aggressive and popularity-driven behaviors in peer social networks.

Aggression, academic behaviors, and popularity perceptions among boys of color during the transition to middle school.

The transition to middle school often presents behavioral and academic challenges to youths. Boys of color (i.e., African American and Hispanic in this study) may be especially vulnerable. In this study, peer nominations of aggressive and academic behaviors as well as youths' perceptions of how these behaviors were related to popularity in peer networks were obtained from the spring semester of fifth grade through the spring semester of seventh grade, with the transition occurring as the students entered the sixth grade. The sample included 188 boys (71 Caucasian, 90 African American, and 27 Hispanic) from an urban school district in the northeastern United States. Trajectory analyses showed that African American boys scored lower in studentship and higher in rule-breaking and aggressive (both physical and social) behaviors prior to the transition, and such differences among ethnic groups were largely maintained during the transition. Hispanic boys displayed decreases in their studentship during the transition. African American boys' perception of how studentship affects popularity was more positive than other boys prior to the transition, but it decreased during the transition. African American boys also endorsed rule breaking and physical and social aggression more positively for popularity prior to the transition, whereas Caucasian and Hispanic boys' endorsement increased during the transition and eventually caught up with those of African American boys in seventh grade. A positive within-individual association was found between youths' popularity perception and their behavior for studentship, rule breaking, and physical aggression, which did not differ by ethnicity.