Nonactivated Aziridine Synthesis by Intermolecular Polarity-Mismatched Carboamination of Unactivated Alkenes with Unactivated Alkyl Halides.

A general intermolecular polarity-mismatched carboamination reaction of unactivated alkenes with unactivated alkyl halides has been developed. A series of nonactivated alkyl-substituted aziridines were constructed in exclusive regioselectivity. The dual polarity-mismatched mechanism might be involved.

Saponin Esculeoside A and Aglycon Esculeogenin A from Ripe Tomatoes Inhibit Dendritic Cell Function by Attenuation of Toll-like Receptor 4 Signaling.

Dendritic cells (DCs) can initiate immune response through the presenting antigens to naïve T lymphocytes. Esculeoside A (EsA), a spirosolane glycoside, is reported as a major component in the ripe fruit of tomato. Little is known about the effect of tomato saponin on mice bone marrow-derived DCs. This study revealed that EsA and its aglycon, esculeogenin A (Esg-A), attenuated the phenotypic and functional maturation of murine DCs stimulated by lipopolysaccharide (LPS). We found that EsA/Esg-A down-regulated the expression of major histocompatibility complex type II molecules and costimulatory molecule CD86 after LPS stimulation. It was also determined that EsA-/Esg-A-treated DCs were poor stimulators of allogeneic T-cell proliferation and exhibited impaired interleukin-12 and TNF-α production. Additionally, EsA/Esg-A was able to inhibit TLR4-related and p-NFκB signaling pathways. This study shows new insights into the immunopharmacology of EsA/Esg-A, and represents a novel approach to controlling DCs for therapeutic application.

Nickel-catalyzed hydrodefluorination/deuterodefluorination of CF3-alkenes with formic acid.

The synthesis of deuterated gem-difluoroalkenes via selective deuterodefluorination of ß-CF3-cinnamates using a nickel catalyst has been reported for the first time. Commercially available deuterated formic acid is a cheap and convenient deuterium source. The nickel-catalyst showed high selectivity for monodefluorination and avoided competitive reactions such as multiple defluorination or hydrogenation.

Nickel-Catalyzed Enantioselective Reductive Arylation of Common Ketones.

A nickel complex of chiral bisoxazolines catalyzed the stereoselective reductive arylation of ketones in high enantioselectivity. A range of common acyclic and cyclic ketones reacted without the aid of directing groups. Mechanistic studies using isolated complex of a chiral bis(oxazoline) (L)Ni(Ar)Br revealed that Mn reduction was not needed, while Lewis acidic titanium alkoxides were critical to ketone insertion.

Four new resin glycosides from Ipomoea muricata seeds: muricatins XIV-XVII.

Ipomoea muricata (L.) Jacq. seeds (Convolvulaceae) are used as a traditional laxative and carminative medicine. Muricatins XIV (1), XV (2), XVI (3), and XVII (4), were isolated from I. muricata seeds as four new resin glycosides, along with seven known compounds, three of which were isolated for the first time as natural products; their structures were determined using MS and NMR spectroscopy. Compounds 1-4 are macrolactones (jalapins); the sugar moieties of 1, 2, and 4 are partially acylated with 2S-methylbutyric acid, while that of 3 is esterified with 2S-methylbutyric and 2S-methyl-3S-hydroxybutyric acids. In addition, the antiviral activities of the seven compounds obtained in this study, together with five known compounds obtained in our previous study into resin glycosides from I. muricata seeds, were evaluated against herpes simplex virus type 1 (HSV-1); their cytotoxicities against HL-60 human promyelocytic leukemia cells were also investigated. All examined jalapins exhibited similar or slightly weaker anti-HSV-1 activities than acyclovir, the positive control; however, the glycosidic acid of 4 was inactive, while its methyl ester was weakly active. On the other hand, cytotoxicity testing against HL-60 cells showed similar results to those observed during anti-HSV-1 activity testing, with the exception that one jalapin was less active.

Cerebral furin deficiency causes hydrocephalus in mice.

Furin is a pro-protein convertase that moves between the trans-Golgi network and cell surface in the secretory pathway. We have previously reported that cerebral overexpression of furin promotes cognitive functions in mice. Here, by generating the brain-specific furin conditional knockout (cKO) mice, we investigated the role of furin in brain development. We found that furin deficiency caused early death and growth retardation. Magnetic resonance imaging showed severe hydrocephalus. In the brain of furin cKO mice, impaired ciliogenesis and the derangement of microtubule structures appeared along with the down-regulated expression of RAB28, a ciliary vesicle protein. In line with the widespread neuronal loss, ependymal cell layers were damaged. Further proteomics analysis revealed that cell adhesion molecules including astrocyte-enriched ITGB8 and BCAR1 were altered in furin cKO mice; and astrocyte overgrowth was accompanied by the reduced expression of SOX9, indicating a disrupted differentiation into ependymal cells. Together, whereas alteration of RAB28 expression correlated with the role of vesicle trafficking in ciliogenesis, dysfunctional astrocytes might be involved in ependymal damage contributing to hydrocephalus in furin cKO mice. The structural and molecular alterations provided a clue for further studying the potential mechanisms of furin.

Research trends and hotspots regarding treatment of obstructive sleep apnea.

Background: Obstructive sleep apnea (OSA) is a type of sleep-disordered breathing disease, with high prevalence and multiple complications. It seriously affects patients' quality of life and even threatens their lives. Early and effective treatment can significantly improve patients' health conditions. Objective: In this study, the main treatment methods, research hotspots and trends of OSA were summarized through bibliometric and visualization analysis. Methods: From the Web of Science Core Collection database, articles on the treatment of OSA from 1999 to 2022 were obtained. CiteSpace and VOSviewer were comprehensively used to visualization of journals, co-authorship of countries, institutions and authors, co-citation of references, keywords cluster and burst. Results: A total of 2,874 publications were obtained, of which 2,584 were concerned adults and 290 about children. In adults' research, Sleep and Breathing is the most published journal (280, 10.84%), the largest number of publications come from the United States (636,24.61%) and the University of Sydney (88, 3.41%), and Pepin JL is the most published author (48, 18.58%). In children's studies, International Journal of Pediatric Otorhinolaryngology is the most published journal (41, 14.14%), the maximum number of publications were also from the United States (123, 42.41%), with the University of Pennsylvania (20, 6.90%) and Marcus CL (15, 5.17%) being the most published institutions and authors. High-frequency keywords for adults' researches include positive airway pressure, oral appliance, surgery and positional therapy. On these basis, children's studies also focus on myofunctional therapy, rapid maxillary expansion and hypoglossal nerve Stimulation. Conclusion: Over the past two decades, research in the field of OSA therapeutics has experienced significant growth in depth and breadth. The author cooperation network has already established a solid foundation, while there is potential for further strengthening the cooperation network between countries and institutions. Currently, positive airway pressure and surgery are the primary treatments for OSA in adults and children. Future research will focus on multidisciplinary combination targeted therapy, which presents a key area of interest and challenge.

The relationship between a growth mindset and the learning engagement of nursing students: A structural equation modeling approach.

AIMS: To explore the relationship among a growth mindset, well-being and learning engagement of nursing students and the mediating effect of well-being. BACKGROUND: Reduced well-being and learning burnout are common among nursing students. From the perspective of positive psychology, a positive education can help students obtain well-being, improve their academic performance and be actively involved in learning. The core of positive education is a growth mindset. However, few studies have explored the causal relationship among a growth mindset, learning engagement and well-being. DESIGN: Correlational design based on cross-sectional data from a multicenter survey study. METHODS: A web-based survey was completed by 1065 nursing students from 5 schools in China between August 2022 and December 2022. The Growth Mindset Scale, the PERMA profiler and the Learning Engagement Scale were used to investigate the effect of a growth mindset on learning engagement and the mediating effect of well-being. RESULTS: Both a growth mindset (r = 0.272, p < 0.01) and well-being (r = 0.693, p < 0.01) were positively correlated with learning engagement, and a growth mindset (r = 0.363, p < 0.01) was positively correlated with well-being. Well-being completely mediated the relationship between a growth mindset and learning engagement. CONCLUSIONS: The growth mindset and well-being of nursing students are related to learning engagement. Therefore, schools can change students' thinking mode by carrying out positive education to enable students to acquire the ability to maintain their well-being and to improve their well-being and learning engagement.

A neutron beam monitor based on ceramic gas electron multiplier with high spatial resolution for low flux measurements.

Neutron scattering instruments play an important role in studying the inner structure of materials. A neutron beam monitor is a detector commonly used in a neutron scattering instrument. The detection efficiency for most neutron beam monitors is quite low (10-4-10-6). However, in some experiments with a low neutron flux, such as small angle neutron scattering (SANS) and inelastic neutron scattering experiments, a neutron beam monitor with a higher detection efficiency (∼1% for thermal neutrons) is required to reduce the duration of the experiment. To meet this requirement, a ceramic gas electron multiplier-based neutron beam monitor equipped with a 1 µm 10B4C neutron converter was developed in this study. Its performance was determined both experimentally and in simulations. The detection efficiency in the wavelength range of 1.8-5.5 Å was measured experimentally and was confirmed by the simulation results. An algorithm based on event selection and position reconstruction was developed to improve the spatial resolution to about 1 mm full-width-half-maximum. The wavelength spectrum was measured in beamline 20 (BL20) and agreed well with the results obtained using a commercial monitor. The maximum counting rate was 1.3 MHz. The non-uniformity over the whole 100 × 100 mm2 active area was determined to be 1.4%. Due to the excellent performance of this monitor, it has been used in several neutron instruments, such as the SANS and the High-Energy Direct-Geometry Inelastic Spectrometer instruments in the China spallation neutron source.

Magnetron sputtering system for depositing boron carbide film use as neutron detection.

Boron carbide (B4C) films used as neutron conversion layers were investigated in this paper to replace the traditional 3He detectors due to their shortage. A magnetron sputtering system was developed for depositing large-size B4C films with the 1500 × 400 mm2 uniform-area. B4C films at the micron scale were deposited on aluminum (Al), float glass (SiO2), and silicon (Si) substrates with an inserting adhesion layer. The key characteristics, including surface morphology, thickness nonuniformity, purity, and neutron efficiency of B4C films, were characterized using atomic force microscopy, scanning electron microscopy, grazing incidence x-ray reflectivity, x-ray photoelectron spectroscopy, and neutron radiation metrology. The experimental results indicate that the deposition thickness nonuniformity across a 1500 × 400 mm2 area was better than ±3%. The stoichiometric ratio of boron atoms and carbon atoms (B/C) is 5.18, with 6 at. % O and 0.79 at. % N concentrations. The measured neutron detection efficiency of a 3 µm 10B4C film for 25 meV neutrons was 3.3 ± 0.3(sys)%, which is close to the simulated results (3.4%). The results show that the B4C neutron conversion layer is a promising substitute for 3He for neutron detection in the future.

Ophiopogonin D ameliorates non­alcoholic fatty liver disease in high­fat diet­induced obese mice by improving lipid metabolism, oxidative stress and inflammatory response.

Lipid metabolic disorders, oxidative stress and inflammation in the liver are key steps in the progression of non-alcoholic fatty liver disease (NAFLD). Ophiopogonin D (OP-D), the main active ingredient of Ophiopogon japonicus, exhibits several pharmacological activities such as antioxidant and anti-inflammatory activities. Therefore, the current study aimed to explore the role of OP-D in NAFLD in a high-fat diet (HFD)-induced obesity mouse model. To investigate the effect of OP-D on NAFLD in vivo, a NAFLD mouse model was established following feeding mice with HFD, then the mice were randomly treated with HFD or HFD + OP-D for 4 weeks. Subsequently, primary mouse hepatocytes were isolated, and enzyme-linked immunosorbent assay, reverse transcription-quantitative PCR western blotting and immunofluorescence analysis were used for assessment to explore the direct effect of OP-D in vitro. The results of the present study indicated that OP-D could ameliorate NAFLD in HFD-induced obese mice by regulating lipid metabolism and antioxidant and anti-inflammatory responses. Additionally, OP-D treatment decreased lipogenesis and inflammation levels in vitro, suggesting that the NF-κB signaling pathway may be involved in the beneficial effects of OP-D on NAFLD.

Prevalence of burnout and mental health problems among medical staff during the COVID-19 pandemic: a systematic review and meta-analysis.

OBJECTIVE: The COVID-19 pandemic has had a significant impact on the burnout and mental health of medical staff. This meta-analysis aims to provide additional (and updated) evidence related to burnout and mental health problems among medical staff using a broader data pool. DESIGN: Systematic review and meta-analysis. DATA SOURCES: PubMed, Embase, Cochrane Library, CNKI, Wanfang data and three preprint databases (SSRN, bioRxiv and medRxiv) were searched from 1 January 2020 to 17 May 2021. ELIGIBILITY CRITERIA: We included observational studies investigating the prevalence of burnout and mental health problems among medical staff during the COVID-19 pandemic, including cross-sectional study, cohort study and case-control study. DATA EXTRACTION AND SYNTHESIS: Two independent reviewers used a self-designed form to extract the primary data. The Joanna Briggs Institute quality appraisal tool was used to assess the quality of selected studies. Heterogeneity among studies was assessed by I2 statistic. A random-effects model was used to pool the prevalence. Subgroup analysis was performed to explore between-group differences. RESULTS: 250 studies were included, with a sample of 292 230 participants from 46 countries. The pooled prevalence of burnout, anxiety, depression, insomnia, stress, post-traumatic stress disorder symptoms and somatic symptoms was 43.6% (95% CI 36.3% to 51.2%), 37.1% (95% CI 34.7% to 39.7%), 37.6% (95% CI 35.0% to 40.4%), 43.7% (95% CI 39.1% to 48.5%), 41.3% (95% CI 35.1% to 47.9%), 30.6% (95% CI 23.6% to 38.5%) and 25.0% (95% CI 16.7% to 35.6%), respectively. Subgroup analysis showed a higher prevalence of anxiety, depression and insomnia in frontline workers than in non-frontline workers, and a higher prevalence of anxiety in females than males. Mild cases accounted for the most significant proportion of the outcomes except for stress. CONCLUSIONS: This study highlights that identifying the risks of burnout and mental health problems and adopting preventive interventions are priorities for policymakers and medical staff to avoid long-term occupational, health and social impacts. PROSPERO REGISTRATION NUMBER: CRD42021254425.

Cobalt-Catalyzed Enantioselective Cross-Electrophile Couplings: Stereoselective Syntheses of 5-7-Membered Azacycles.

Cobalt complexes of chiral pyrox ligands catalyzed enantioselective reductive couplings of nonconjugated iododienes with aryl iodides or alkenyl bromides. The reaction enabled stereoselective syntheses of 5-7-membered azacycles carrying quaternary stereocenters. Mechanistically, cross-electrophile selectivity originated from selective coupling of alkylcobalt(I) complexes generated after cyclization with aryl iodides.

Regioselective and Geometrically Controlled Heck 1,1-Diarylation of Unactivated Aliphatic Alkenes.

Pd-catalyzed double Heck reaction allows regioselective 1,1-diarylation of unactivated aliphatic alkenes. When two different aryl bromides are used, the second aryl rings are added trans to aliphatic chains in the main olefinic isomers, consistent with a mechanism of two consecutive Heck arylations at the terminal carbons.

Inhibition of suplatast tosilate on EPSC in the single paratracheal ganglion neurons attached with presynaptic boutons.

Using single neurons of rat paratracheal ganglia (PTG) attached with presynaptic boutons, the effects of suplatast tosilate on excitatory postsynaptic currents (EPSCs) were investigated with nystatin-perforated patch-clamp recording technique. We found that suplatast concentration dependently inhibited the EPSC amplitude and its frequency in single PTG neurons attached with presynaptic boutons. EPSC frequency was higher sensitive to suplatast than EPSC amplitude. IC50 for EPSC frequency was 1.1 × 10-5 M, being similar to that for the effect on histamine release from mast cells and lower than that for the inhibitory effect on cytokine production. Suplatast also inhibited the EPSCs potentiated by bradykinin (BK), but it did not affect the potentiation itself by BK. Thus suplatast inhibited the EPSC of PTG neurons attached with presynaptic boutons at both the presynaptic and postsynaptic sites.NEW & NOTEWORTHY In this study, using single neurons of rat paratracheal ganglia (PTG) attached with presynaptic boutons, the effects of suplatast tosilate on excitatory postsynaptic currents (EPSCs) were investigated with patch-clamp recording technique. We found that suplatast concentration dependently inhibited the EPSC amplitude and its frequency in single PTG neurons attached with presynaptic boutons. Thus suplatast inhibited the function of PTG neurons at both of presynaptic and postsynaptic sites.

The Effects of Orofacial Myofunctional Therapy on Children with OSAHS's Craniomaxillofacial Growth: A Systematic Review.

Orofacial myofunctional therapy (OMT) is one of the therapeutic methods for neuromuscular re-education and has been considered as one of the auxiliary methods for obstructive sleep apnea hypopnea syndrome (OSAHS) and orthodontic treatment. There is a dearth of comprehensive analysis of OMT's effects on muscle morphology and function. This systematic review examines the literature on the craniomaxillofacial effects of OMT in children with OSAHS. This systematic analysis was carried out using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) standards, and the research was scanned using PICO principles. A total of 1776 articles were retrieved within a limited time, with 146 papers accepted for full-text perusing following preliminary inspection and 9 of those ultimately included in the qualitative analysis. Three studies were rated as having a severe bias risk, and five studies were rated as having a moderate bias risk. Improvement in craniofacial function or morphology was observed in most of the 693 children. OMT can improve the function or morphology of the craniofacial surface of children with OSAHS, and its effect becomes more significant as the duration of the intervention increases and compliance improves. In the majority of the 693 infants, improvements in craniofacial function or morphology were seen. The function or morphology of a kid's craniofacial surface can be improved with OMT, and as the duration of the intervention lengthens and compliance rises, the impact becomes more pronounced.

Nickel-Catalyzed Enantioselective Reductive Arylation and Heteroarylation of Aldimines via an Elementary 1,4-Addition.

Nickel catalysts of chiral pyrox ligands promoted enantioselective reductive arylation and heteroarylation of aldimines, using directly (hetero)aryl halides and sulfonates. The catalytic arylation can also be conducted with crude aldimines generated from condensation of aldehydes and azaaryl amines. Mechanistically, density functional theory (DFT) calculations and experiments pointed to an elementary step of 1,4-addition of aryl nickel(I) complexes to N-azaaryl aldimines.

Garlicnin B1, an Active Cyclic Sulfide from Garlic, Exhibits Potent Anti-Inflammatory and Anti-Tumor Activities.

This study aimed to investigate the pharmacological activities of garlicnin B1, a cyclic sulfide compound found abundantly in garlic and structurally similar to onionin A1, which has been shown to possess strong anti-tumor effects. In vitro studies demonstrated that garlicnin B1 significantly reduced intracellular reactive oxygen species triggered by hydrogen peroxide in colon cancer cells. In a mouse colitis model induced by dextran sulfate sodium, garlicnin B1 at a low dose (5 mg/kg) remarkably ameliorated the symptoms and pathological progression. Additionally, garlicnin B1 exhibited considerable tumoricidal activity with an IC50 value of ~20 µM, as observed in cytotoxicity assays. In vivo experiments using the mouse sarcoma S180 transplanted model and the azoxymethane (AOM) or DSS-induced colon cancer model showed that garlicnin B1 effectively suppressed tumor growth in a dose-dependent manner, with marked inhibition at 80 mg/kg. These results suggest that garlicnin B1 has diverse functions that could be achieved by carefully manipulating the dosing regimen. We anticipate that garlicnin B1 has the potential to be used beneficially in the future for the treatment of cancer and inflammatory diseases, although further studies are warranted to elucidate its mechanisms of action.

Catalytic enantioselective alkenylation-heteroarylation of olefins: stereoselective syntheses of 5-7 membered azacycles and oxacycles.

Catalytic enantioselective domino alkenylation-heteroarylation of nonconjugated iododienes proceeded with excellent stereoselectivity and broad scope of substrates. The reaction enables stereoselective syntheses of substituted azacycles such as piperidine, pyrrolidine azepine and dihydropyrans carrying new quaternary stereocenters. Mechanistically, C-H bonds of heterocycles were activated by lithium alkoxides via reversible deprotonation, rather than conventional palladium(ii)-assisted metalation processes. Many types of heteroarenes can be used, including not only azoles (such as thiazoles, oxazoles, imidazoles and oxadiazoles), but also nonazoles (thiophene, furan and azine N-oxides).

Cobalt-Catalyzed Asymmetric Deuteration of α-Amidoacrylates for Stereoselective Synthesis of α,ß-Dideuterated α-Amino Acids.

A cobalt-catalyzed deuteration of amidoacrylates using deuterated methanol afforded α,ß-dideuterio-α-amino esters in excellent enantiomeric ratios (mostly >95 : 5) and almost complete deuteration (99 %). The new protocol was used to prepare dideuterio-α-amino acid fragments in some drugs. Furthermore, the stereoselective deuteration was applied in a concise synthesis of dideuterio l-DOPA.