Cu/Fe Catalyzed Intermolecular Oxidative Amination of Benzylic C-H Bonds.

We report a Cu/Fe co-catalyzed Ritter-type C-H activation/amination reaction that allows efficient and selective intermolecular functionalization of benzylic C-H bonds. This new reaction is featured by simple reaction conditions, readily available reagents and general substrate scope, allowing facile synthesis of biologically interesting nitrogen containing heterocycles. The Cu and Fe salts were found to play distinct roles in this cooperative catalysis.

Increased Expression of Rac1 in Epilepsy Patients and Animal Models.

The mechanisms of epilepsy remain incompletely understood. Rac1 (ras-related C3 botulinum toxin substrate 1) belongs to the Rho family of small GTPases. Rac1 play important roles in cytoskeleton rearrangement and neuronal synaptic plasticity, which had also been implicated in epilepsy. However, little is known regarding the expression of Rac1 in the epileptic brain or whether Rac1-targeted interventions affect the progression of epilepsy. The aim of this study was to investigate the expression profile of Rac1 in brain tissues from patients suffering from temporal lobe epilepsy (TLE) and experimental epileptic rats and determine the possible role of Rac1 in epilepsy. We demonstrated that the expression of Rac1 is significantly increased in TLE patients and in lithium-pilocarpine epilepsy model animals compared to the corresponding controls. Rac1 inhibitor NSC23766 reduced the severity of status epilepticus during the acute stage in a lithium-pilocarpine animal model. Consistent with these results, the latent period of a PTZ kindling animal model also increased. Our results demonstrated that the increased expression of Rac1 may contribute to pathophysiology of epilepsy.

Rhodium-Catalyzed Intramolecular C-H Silylation by Silacyclobutanes.

Silacyclobutane was discovered to be an efficient C-H bond silylation reagent. Under the catalysis of Rh(I) /TMS-segphos, silacyclobutane undergoes sequential C-Si/C-H bond activations, affording a series of π-conjugated siloles in high yields and regioselectivities. The catalytic cycle was proposed to involve a rarely documented endocyclic ß-hydride elimination of five-membered metallacycles, which after reductive elimination gave rise to a Si-Rh(I) species that is capable of C-H activation.

Comparative analysis of salt-responsive phosphoproteins in maize leaves using Ti(4+)--IMAC enrichment and ESI-Q-TOF MS.

Salinity is one of the most common abiotic stresses encountered by plants. Reversible protein phosphorylation is involved in plant defense processes against salinity stress. Here, we performed global phosphopeptide mapping through enrichment by our synthesized PVA-phosphate-Ti(4+) IMAC coupled with subsequent identification by ESI-Q-TOF MS. A total of 104 peptide sequences containing 139 phosphorylation sites were determined from 70 phosphoproteins of the control leaves. In contrast, 124 phosphopeptides containing 143 phosphorylated sites from 92 phosphoproteins were identified in salt-stressed maize leaves. Compared with the control, 47 proteins were phosphorylated, 25 were dephosphorylated, and 45 overlapped. Among the 72 differential phosphoproteins, 35 were known salt stress response proteins and the rest had not been reported in the literature. To dissect the differential phosphorylation, gene ontology annotations were retrieved for the differential phosphoproteins. The results revealed that cell signaling pathway members such as calmodulin and 14-3-3 proteins were regulated in response to 24-h salt stress. Multiple putative salt-responsive phosphoproteins seem to be involved in the regulation of photosynthesis-related processes. These results may help to understand the salt-inducible phosphorylation processes of maize leaves.

Preparation and loading buffer study of polyvinyl alcohol-based immobilized Ti4+ affinity chromatography for phosphopeptide enrichment.

Despite recent advances in phosphoproteomics, an efficient and simple enrichment protocol is still a challenge and of high demand aiming at large-scale plant phosphoproteomics studies. Here, we developed a novel loading buffer system for synthesized immobilized metal affinity chromatography material targeting plant samples, which was prepared by a simple one-step esterification between polyvinyl alcohol and phosphoric acid and then was subjected to immobilize Ti(4+). SEM and Fourier transform IR spectroscopy were used to assure the synthesis protocol of the polyvinyl alcohol-based Ti(4+) immobilized material, and the specific surface areas and pore volumes of the polymers were measured. The selectivity for phosphopeptide enrichment from α-casein was improved by optimizing the pH and components of the loading buffer. By using potassium hydrogen phthalate/hydrochloric acid with pH at 2.50 as the loading buffer, 19 phosphopeptides with high intensity were identified. The final optimized protocol was adapted to salt-stressed maize leaves for phosphoproteome analysis. A total of 57 phosphopeptides containing 59 phosphorylated sites from 50 phosphoproteins were identified in salt-stressed maize leaf. The research was meaningful to obtain much more information about phosphoproteins leading to the comprehension of salt resistance and salt-inducible phosphorylated processes of maize leaves.

Parametric Study on Low-Velocity Impact (LVI) Damage and Compression after Impact (CAI) Strength of Composite Laminates.

A full-scale model for predicting low-velocity impact (LVI) damage and compression after impact (CAI) strength was established based on a subroutine of the material constitutive relationship and the cohesive elements. The dynamic responses of the laminate under impact load and damage propagation under a compressive load were presented. The influences of impact energy and ply thickness on the impact damage and the CAI strength were predicted. The predicted results were compared with the experimental ones. It is shown that the predicted value of the CAI strength is in good agreement with the experimental result. As the impact energy reaches a certain value, the CAI strength no longer decreases with the increase in the impact energy. Decreasing the ply thickness can effectively improve the damage resistance and CAI strength.

Adolescent resilience and mobile phone addiction in Henan Province of China: Impacts of chain mediating, coping style.

BACKGROUND: As mobile phone use grows, so it brings benefits and risks. As an important part of adolescents healthy growth, resilience plays an indispensable role. Thus, it is important to identify when mobile phone use of an adolescent becomes an addiction. This study proposed to explore the effects of adolescent resilience on mobile phone addiction, and tested the mediating role of coping style and depression, anxiety, and stress (DASS) on phone addiction among 2,268 adolescents in the Henan province, China. METHODS: The adolescents were surveyed via an online questionnaire, a mobile phone addiction index (MPAI), a depression, anxiety, and stress scale with 21 items (DASS-21), the Resilience Scale for Chinese Adolescents (RSCA), and the Simplified coping style questionnaire (SCSQ), and we used structural equation modeling to examine the correlations and moderation effects. All data analyses were performed using SPSS 26.0 and Amos 23.0. RESULTS: The results show that adolescences resilience were negatively related to negative coping, DASS, and mobile phone addiction; both coping style and DASS could mediate the relationship between adolescent resilience and mobile phone addiction among Chinese adolescents. The relationship between adolescent resilience and mobile phone addiction in Chinese adolescents was mediated by the chain of coping styles and DASS. CONCLUSIONS: There is a negative relationship which exists between resilience and mobile phone addiction in this population. In addition, stress, anxiety, depression, and coping style significantly influence the risk of adolescent mobile phone addiction and play an intermediary role in Chinese adolescent resilience and mobile phone addiction.

The Impact of Adolescent Resilience on Mobile Phone Addiction During COVID-19 Normalization and Flooding in China: A Chain Mediating.

Natural disasters cause long-term psychological problems and increase substance use in some adults. However, it is unclear whether disasters also lead to these problems in adolescents. We hypothesized the influence of adolescent resilience on mobile phone addiction during the normalization of COVID-19 and flooding. We tested the mediating role of coping style and depression, anxiety, and stress (DASS) on phone addiction among 1,751 adolescents in the Henan Province in China. The adolescents were surveyed via an online questionnaire, and we used structural equation modeling to examine the correlations and moderation effects. The results show that coping style and DASS could mediate the relationship between adolescent resilience and mobile phone addiction among Chinese adolescents. A chain of coping styles and DASS mediated the relationship between adolescent resilience and mobile phone addiction in Chinese adolescents.

Interleukin-7 promotes CD8+ T cell activity in patients with enterovirus 71 associated encephalitis.

Enterovirus 71 (EV71) always induces severe hand, foot, and mouth disease with neurological complications, such as encephalitis. Interleukin (IL)-7 augments CD8+ T cells activity in chronic viral infection and cancers. However, few studies have focused on common γ-chain (γc) cytokine expression and regulatory function of IL-7 to CD8+ T cells in EV71 associated encephalitis. In this study, twenty-one patients with EV71 associated encephalitis, twenty-seven patients with febrile convulsion (FC), and twenty healthy individuals were enrolled. γc cytokine (IL-2, IL-4, IL-7 and IL-15) concentration was measured by ELISA. IL-7 receptor α chain (membrane/soluble CD127) expression was also investigated. Purified CD8+ T cells were stimulated with recombinant human IL-7 in vitro. The regulatory activity of IL-7 to CD8+ T cells from peripheral blood and cerebrospinal fluids (CSF) was investigated in direct and indirect contact co-culture with U-87MG cells. IL-7 in the serum and CSF, but not IL-2, IL-4, or IL-15, was significant increased in EV71 associated encephalitis. Both total CD127 mRNA relative level and membrane/soluble CD127 expression was comparable among three groups. IL-7 stimulation promoted CD8+ T cells proliferation, up-regulated perforin/granzyme B level, but reduced programmed death-1 expression in CD8+ T cells from EV71 associated encephalitis patients. Cytotoxicity and interferon-γ production of CD8+ T cells from peripheral blood and CSF was also augmented in response to IL-7 stimulation in both direct and indirect co-culture systems in EV71 associated encephalitis. The present data indicated that IL-7 induced cytolytic and non-cytolytic functions of CD8+ T cells in EV71 associated encephalitis. IL-7 might be considered as one of the immunomodulatory therapeutic candidates for EV71 infection.

Evolution of Staircase Structures in Diffusive Convection.

Diffusive convection (DC) occurs when the vertical stratified density is controlled by two opposing scalar gradients that have distinctly different molecular diffusivities, and the larger- and smaller- diffusivity scalar gradients have negative and positive contributions for the density distribution, respectively. The DC occurs in many natural processes and engineering applications, for example, oceanography, astrophysics and metallurgy. In oceans, one of the most remarkable features of DC is that the vertical temperature and salinity profiles are staircase-like structure, composed of consecutive steps with thick homogeneous convecting layers and relatively thin and high-gradient interfaces. The DC staircases have been observed in many oceans, especially in the Arctic and Antarctic Oceans, and play an important role on the ocean circulation and climatic change. In the Arctic Ocean, there exist basin-wide and persistent DC staircases in the upper and deep oceans. The DC process has an important effect on diapycnal mixing in the upper ocean and may significantly influence the surface ice-melting. Compared to the limitations of field observations, laboratory experiment shows its unique advantage to effectively examine the dynamic and thermodynamic processes in DC, because the boundary conditions and the controlled parameters can be strictly adjusted. Here, a detailed protocol is described to simulate the evolution process of DC staircase structure, including its generation, development and disappearance, in a rectangular tank filled with stratified saline water. The experimental setup, evolution process, data analysis, and discussion of results are described in detail.

Silylation reactions on nanoporous gold via homolytic Si-H activation of silanes.

Si-H bond activation is an important process implicated in many useful synthetic applications including silylation and transfer hydrogenation reactions. Herein we discovered homolytic activation of Si-H bonds on the surface of nanoporous gold (NPG), forming hydrogen radicals and [Au]-[Si] intermediates. By virtue of this new reactivity, we achieved highly selective mono and sequential alcoholysis of dihydrosilane. In addition, the amphiphilic nature of the [Au]-[Si] intermediate allows for a new bis-silylation reaction of cyclic ethers. The present work showcased that the surface reactivity of nanocatalysts may provide exciting opportunity for new reaction discovery.

MicroRNA-135b has a neuroprotective role via targeting of ß-site APP-cleaving enzyme 1.

MicroRNAs (miRs) are a class of endogenous small non-coding RNAs that have been revealed to negatively mediate the expression of their target genes at the post-transcriptional level. Recently, particular miRs have demonstrated an involvement in the pathogenesis of Alzheimer's disease (AD). However, the specific role of miR-135b in AD has yet to be elucidated. The present study aimed to investigate the neuroprotective role of miR-135b, in addition to its underlying mechanism. Herein, reverse transcription-quantitative polymerase chain reaction was conducted to determine miR-135b expression levels in the peripheral blood samples of patients with AD and age-matched normal controls. The data of the present study revealed that the expression levels of miR-135b were significantly reduced in the peripheral blood of AD patients compared with normal controls (P<0.01). In vitro MTT analyses identified that the overexpression of miR-135b significantly enhanced the proliferation of hippocampal cells (P<0.01). Furthermore, in vivo analysis using a Y-maze test indicated that injection with miR-135b mimics into the third ventricle of anesthetized SAMP8 mice significantly enhanced their learning and memory capacities (P<0.01). Molecular mechanism investigations identified ß-site APP-cleaving enzyme 1 (BACE1) as a direct target gene of miR-135b, and the latter was identified to negatively mediate the protein expression levels of BACE1 in hippocampal cells, in addition to hippocampal tissues, of SAMP8 mice. Based on the aforementioned findings, we propose that miR-135b has a neuroprotective role via direct targeting of BACE1 and, thus, may be used for the treatment of AD.

Upregulation of microRNA-206 enhances lipopolysaccharide-induced inflammation and release of amyloid-ß by targeting insulin-like growth factor 1 in microglia.

Activated microglia are capable of facilitating amyloid-ß (Aß) accumulation via the release of inflammatory factors, thus resulting in the exacerbation of Alzheimer's disease (AD). MicroRNAs (miRs) participate in the activation of microglia, which is associated with AD. Insulin-like growth factor 1 (IGF1) is a neuroprotective, anti-inflammatory factor, which is able to accelerate clearance of Aß peptides. The present study aimed to investigate the precise role of miR­206 and IGF1 in lipopolysaccharide (LPS)­induced microglial inflammation. The expression levels of miR­206 and IGF1 were detected in 60 peripheral blood samples from patients with AD and matched age subjects using quantitative polymerase chain reaction. A dual luciferase reporter gene assay was used to indicate the relationship between miR­206 and IGF1. In addition, the role of miR­206 was determined by gain and loss of function experiments in LPS­treated microglia. The results demonstrated that miR­206 upregulation enhanced LPS­induced inflammation and Aß release in microglia by directly targeting the 3'-untranslated region of IGF1. These effects were attenuated following treatment with exogenous IGF1, thus indicating that the miR­206/IGF1 signaling pathway may be considered a novel therapeutic target for the treatment of AD­associated microglial inflammation.

Relationship between lipoprotein lipase gene polymorphism and hemorrhagic stroke in a Chinese population.

OBJECTIVE: To investigate the relationship between lipoprotein lipase (LPL) gene polymorphism and cerebral hemorrhage in a Chinese population. METHOD: This study was based on the case-control study, PCR-RELP and sequencing method were utilized for genotyping. LPL gene Hind III polymorphism was detected both in 300 patients with cerebral hemorrhage (CH group) and in 300 healthy control subjects (control group). Blood lipid level and blood glucose were detected at the same time. RESULT: Our results showed that G allele frequency was significant lower in the CH group than that in the control group (OR=0.611; 95% CI: 0.427-0.876, P=0.001). We also found both GG (OR=0.543, 95% CI: 0.233-0.988; P=0.041) and TG (OR=0.609, 95% CI: 0.387-0.959, P=0.032) genotype were frequent in the control group than that in the CH group. TG level of the groups who carry TT genotype were much higher than that of the groups carrying TG+GG genotype (P<0.05). By means of adjusting age, hypertension and hyperglycemia, logistic multivariate regression analysis revealed that LPL Hind III G allele might be a protective factor (OR=0.601, 95% CI: 0.231-0.876; P=0.001) in the present study. CONCLUSION: It is suggested that LPL Hind III G allelic mutation might be a protective factor against cerebral hemorrhage disease in Chinese population.

Plasma levels of copeptin predict 1-year mortality in patients with acute ischemic stroke.

To evaluate the association between plasma levels of copeptin and 1-year mortality in a cohort of Chinese patients with acute ischemic stroke. We prospectively studied 275 patients with ischemic stroke who were admitted within 24 h after the onset of symptoms. Copeptin and NIH stroke scale (NIHSS) score were measured at the time of admission. The prognostic value of copeptin to predict mortality within 1 year was compared with the NIHSS score and other known outcome predictors. Nonsurvivors had significantly higher copeptin levels on admission compared with survivors (P<0.0001). Multivariate logistic regression analysis showed that elevated plasma levels of copeptin were an independent stroke mortality predictor, with an adjusted odds ratio of 4.48 [95% confidence interval (CI), 2.18-9.06]. The area under the receiver operating characteristic curve of copeptin was 0.882 (95% CI, 0.847-0.921) for stroke mortality, which yielded a sensitivity of 90.7% and a specificity of 84.5%. Copeptin improved the NIHSS score (area under the curve of the combined model, 0.94; 95% CI, 0.91-0.97; P=0.011). Elevated plasma copeptin levels at admission were an independent predictor of long-term mortality after ischemic stroke in a Chinese sample, suggesting that these alterations might play a role in the pathophysiology of stroke.

Effect of oxytocin on the behavioral activity in the behavioral despair depression rat model.

Oxytocin (OXT), a nonapeptide posterior hormone of the pituitary, is mainly synthesized and secreted in the hypothalamic paraventricular nucleus (PVN) and supraoptic nucleus (SON). The present study was to investigate in which level, brain or periphery, OXT effecting on the behavioral activity in the behavioral despair depression rat model. The results showed that (1) either the forced swimming or the tail suspension significantly increased OXT concentration in the brain (PVN, SON, frontal cortex, hippocampus, amygdala, lumbar spinal cord) and in the periphery (posterior pituitary and serum); (2) intraventricular injection (icv) of OXT decreased the animal immobility time, whereas OXT receptor antagonist-desGly-NH2, d(CH2)5[D-Tyr2, Thr-sup-4]OV (icv) increased the animal immobility time in a dose-dependent manner in forced swimming test (FST) and in tail suspension test (TST); (3) neither OXT nor OXT receptor antagonist (intravenous injection) influenced the animal immobility time in FST and in TST. OXT levels were increased in several areas of the brain and in the periphery following the behavioral despair, one stressor, yet pre-treatment with OXT appeared to be beneficial in term of reducing immobility time. The data suggested that behavioral despair could enhance OXT synthesis and secretion not only in the brain but also in the periphery, and OXT in the brain rather than the periphery played a role in the behavioral despair depression.