Background:Although previous studies indicate that perceived social support might be associated with adolescent psychological problems,the specific mechanism has not been thoroughly *** on theoretical and empirical re...
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Background:Although previous studies indicate that perceived social support might be associated with adolescent psychological problems,the specific mechanism has not been thoroughly *** on theoretical and empirical research on problematic Internet use(PIU)and sleep quality,this study explored whether they play a mediating role between perceived social support and symptoms of depression and anxiety among ***,we investigated whether these relationships varied by place of ***:A sample of 2115 Chinese adolescents was included,and analyzed data related to perceived social support,PIU,sleep quality,symptoms of depression and anxiety,and sociodemographic *** analysis,mediation,and moderation analysis were mainly ***:Perceived social support was negatively correlated with depressive symptoms(r=−0.22,p<0.001)and anxiety symptoms(r=−0.20,p<0.001)among *** and sleep quality played a chain mediating role in the relationship between perceived social support and symptoms of depression and anxiety in ***,the place of residence moderated the relationships between perceived social support and PIU and symptoms of depression and *** social support was a significant negative predictor of PIU and symptoms of depression and anxiety among adolescents in urban areas but not in rural ***:The findings suggest that low levels of perceived social support may lead to more PIU and poorer sleep quality,which may further increase the risk of symptoms of depression and anxiety in adolescents,especially in urban areas.
BACKGROUND Crohn's disease(CD)is a chronic inflammatory disease of the gastrointestinal tract,often requiring intestinal resection as a common ***,recurrence after surgery is *** anastomotic configuration after bowel ...
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BACKGROUND Crohn's disease(CD)is a chronic inflammatory disease of the gastrointestinal tract,often requiring intestinal resection as a common ***,recurrence after surgery is *** anastomotic configuration after bowel resection appears to be associated with the recurrence of *** studies have suggested that the Kono-S anastomosis may help to reduce the recurrence ***,the results remain ***,evidence-based evidence is needed to prove the advantages of Kono-S *** To measure the influence of anastomosis techniques on the long-term relapse rate of CD by conducting a *** PubMed,Scopus,and Cochrane Library were searched until October 8,*** who underwent intestinal resection due to CD were *** intervention measures included Kono-S anastomosis,whereas the control group received traditional anastomosis such as end-to-end,end-to-side,and side-to-side *** randomized clinical trials and observational studies were *** primary outcome measures were hospital stay post-surgery,overall postoperative complication incidence,the proportion of Clavien-Dindo grade IIIa or higher,overall postoperative recurrence rate,and Rutgeerts *** From 2011 to 2023,six articles met the inclusion and exclusion *** results indicated that Kono-S anastomosis can reduce the hospital stay post-surgery of patients with CD[MD=-0.26,95%CI:-0.42 to-0.10,P=0.002]than other traditional anastomosis *** to other traditional anastomosis methods,Kono-S anastomosis can significantly reduce the total recurrence rate[MD=0.40,95%CI:0.17 to 0.98,P=0.05]and postoperative Rutgeerts score[MD=-0.81,95%CI:-0.96 to-0.66,P<0.001]in patients with ***,there is no significant disparity in the overall occurrence of postoperative complications and the proportion of Clavien-Dindo≥*** Kono-S anastomosis has the potential to expedite the recuperation of CD and di
Defects at the grain boundaries(GBs) of perovskite film highly restrict both the efficiency and stability of perovskite solar cells(PSCs). Herein, organic small molecules of butanedioic acid(BA) and acetylenedicarboxy...
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Defects at the grain boundaries(GBs) of perovskite film highly restrict both the efficiency and stability of perovskite solar cells(PSCs). Herein, organic small molecules of butanedioic acid(BA) and acetylenedicarboxylic acid(AA), containing two carbonyl(C=O) groups and different core-units, were incorporated into perovskite as additives for PSCs application. Thanks to the strong coordination interaction between C=O group and under-coordinated Pb2+, the additives can effectively passivate film defects and regulate the perovskite crystallization, yielding high-quality perovskite films with lower defect densities. More importantly, the additives can efficiently regulate the charge transport behaviors in PSCs. Benefiting from the defects passivation and the regulation of charge carrier dynamics, the BA and AA-treaded PSCs show the power conversion efficiencies of 21.52% and 20.50%, which are higher than that of the control device(19.41%). Besides, the optimal devices exhibit a remarkable enhanced long-term stability and moisture tolerance compared to the pristine devices. Furthermore, the transient absorption spectrum reveals the mechanism of enhanced photovoltaic performances, attributing to the improvement of charge transport capability at the perovskite/Spiro-OMeTAD interfaces. This work affords a promising strategy to improve the efficiency and stability of PSCs through regulating the charge-carrier dynamic process in perovskite film.
The efficient separation of fission products,such as TcO_(4)^(-)and I^(-),holds strategic significance for the management of radioactive wastes and environmental *** this study,we propose an ultrafast strategy for sca...
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The efficient separation of fission products,such as TcO_(4)^(-)and I^(-),holds strategic significance for the management of radioactive wastes and environmental *** this study,we propose an ultrafast strategy for scalable preparation of a highly quaternized organic network to facilitate efficient and synchronous separation of iodide and *** network can be prepared within a few minutes at room temperature,using polyethylenimine and 1,2,4,5-tetrakis(bromomethyl)benzene as building *** chlorine replacement,the network,abundantly decorated with quaternary ammonium groups(Cl@QPN),exhibits an ultrahigh positive charge density of 7.6 mmol/*** enables the rapid and efficient enrichment of target anions through strong electrostatic Coulomb *** a result,Cl@QPN exhibits significantly higher adsorption rate constants of 0.830 g/(mg min)for ReO_(4)^(-)(a nonradioactive surrogate of TcO_(4)^(-))and 0.677 g/(mg min)for I-compared to other ***,it possesses high adsorption capacities,reaching 1,681 mg/g for ReO_(4)^(-)and 917.4 mg/g for I-.Cl@QPN also demonstrates good selectivity towards target ions and shows efficient adsorption for^(99)TcO_(4)^(-).Additionally,Cl@QPN exhibits high dynamic processing capacities,handling up to 3,100 and 7,400 kg of simulated streams per kilogram of material for I-and ReO_(4)^(-),respectively.
Microporosity formed in the solidification process of Al alloys is detrimental to the alloy properties.A two-dimensional cellular automaton(CA)model was developed to simulate the microstructure and microporosity forma...
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Microporosity formed in the solidification process of Al alloys is detrimental to the alloy properties.A two-dimensional cellular automaton(CA)model was developed to simulate the microstructure and microporosity formation in Al-Cu alloys,considering variations in Cu content and solidification *** results indicate that the Cu content primarily influences the growth of *** validate the model,directional solidification experiments were conducted on Al-Cu alloys with varing Cu contents and withdrawal *** experimental results of dendrites and microporosity characteristics agree well with the predictions from the developed model,thus confirming the validity of the *** alloy’s liquidus temperature,dendrite morphology,and hydrogen saturation solubility arising from different Cu contents have significant effects on microporosity *** withdrawal rate primarily affects the nucleation of hydrogen microporosity by altering cooling rates and dendritic growth rates,resulting in different microporosity characteristics.
Background The mechanism of cerebral vasospasm following subarachnoid haemorrhage （SAH） is not understood. Here, we hypothesized that apoptosis of endothelial cells induced by p53 and its target gene em dash p53 upr...
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Background The mechanism of cerebral vasospasm following subarachnoid haemorrhage （SAH） is not understood. Here, we hypothesized that apoptosis of endothelial cells induced by p53 and its target gene em dash p53 upregulated modulator of apoptosis （PUMA） played an important role in development of cerebral vasospasm. We also observed the effects of a p53 inhibitor, pifithrin-α （PFT-α）, on reducing the expression of p53 and PUMA, consequently decreasing the apoptosis of endothelial cells and alleviating cerebral vasospasm. Methods Male Sprague-Dawley rats weighing 300-350 g were randomly divided into five groups： a control group （sham surgery）, a SAH group, a SAH＋dimethyl sulfoxide （DMSO） group, a SAH＋PFT-α （0.2 mg/kg） group and a SAH＋PFT-α （2.0 mg/kg） group. PFT-α was injected intraperitoneally immediately after SAH. Rats were sacnficed 24 hours after SAH. Western blot and immunohistochemical staining were used to detect the levels of p53, PUMA and caspase-3 protein. In addition, mortality and neurological scores were assessed for each group. Statistical significance was assured by analysis of variance performed in one way ANOVA followed by the Tukey test. The neurological and mortality scores were analyzed by Dunn＇s method and Fisher exact test, respectively. Results After SAH, Western blot and immunohistochemical staining showed the levels of p53, PUMA and caspase-3 in the endothelial cells and the numbers of TdT mediated dUTP nick end labelling （TUNEL） positive endothelial cells were all significantly increased in the basilar arteries （P 〈0.05）, but significantly reduced by PFT-a （P 〈0.05）. These changes were accompanied by increasing diameters and declining wall thickness of basilar arteries （P〈O.05）, as well as reduced mortality and neurological deficits of the rats （P〈O.05）. Conclusions PFT-a could protect cerebral vessels from development of vasospasm and improve neurological outcome as well as reduce the mortality via suppressing apoptosis induced by p53 in th
Pyridyl-based ketones and 1,6-diketones are both attractive and invaluable scaffolds which play pivotal roles in the construction and structural modification of a plethora of synthetically paramount natural products, ...
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Pyridyl-based ketones and 1,6-diketones are both attractive and invaluable scaffolds which play pivotal roles in the construction and structural modification of a plethora of synthetically paramount natural products, pharmaceuticals, organic materials and fine chemicals. In this context, we herein demonstrate an unprecedented, robust and generally applicable synthetically strategy to deliver these two crucial ketone frameworks via visible-light-induced ring-opening coupling reactions of cycloalcohols with vinylazaarenes and enones, respectively. A plausible mechanism involves the selective β-C-C bond cleavage of cycloalcohols enabled by proton-coupled electron transfer and ensuing Giese-type addition followed by single electron reduction and protonation. The synthetic methodology exhibits broad substrate scope,excellent functional group compatibility as well as operational simplicity and environmental friendliness.
The time-varying periodic variations in Global Navigation Satellite System(GNSS) stations affect the reliable time series analysis and appropriate geophysical interpretation. In this study, we apply the singular spect...
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The time-varying periodic variations in Global Navigation Satellite System(GNSS) stations affect the reliable time series analysis and appropriate geophysical interpretation. In this study, we apply the singular spectrum analysis(SSA) method to characterize and interpret the periodic patterns of GNSS deformations in China using multiple geodetic datasets. These include 23-year observations from the Crustal Movement Observation Network of China(CMONOC), displacements inferred from the Gravity Recovery and Climate Experiment(GRACE), and loadings derived from Geophysical models(GM). The results reveal that all CMONOC time series exhibit seasonal signals characterized by amplitude and phase modulations, and the SSA method outperforms the traditional least squares fitting(LSF) method in extracting and interpreting the time-varying seasonal signals from the original time series. The decrease in the root mean square(RMS) correlates well with the annual cycle variance estimated by the SSA method, and the average reduction in noise amplitudes is nearly twice as much for SSA filtered results compared with those from the LSF method. With SSA analysis,the time-varying seasonal signals for all the selected stations can be identified in the reconstructed components corresponding to the first ten eigenvalues. Moreover, both RMS reduction and correlation analysis imply the advantages of GRACE solutions in explaining the GNSS periodic variations,and the geophysical effects can account for 71% of the GNSS annual amplitudes, and the average RMS reduction is 15%. The SSA method has proved to be useful for investigating the GNSS timevarying seasonal signals. It could be applicable as an auxiliary tool in the improvement of nonlinear variations investigations.
The La_(1.7)Pr_(0.3)Mg_(16)Ni hydrogen storage alloy was prepared by medium-frequency induction melting,and then the composite hydrogen storage alloy powder of La_(1.7)Pr_(0.3)Mg_(16)Ni+x wt.%(x=0,2,4,and 6)graphene w...
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The La_(1.7)Pr_(0.3)Mg_(16)Ni hydrogen storage alloy was prepared by medium-frequency induction melting,and then the composite hydrogen storage alloy powder of La_(1.7)Pr_(0.3)Mg_(16)Ni+x wt.%(x=0,2,4,and 6)graphene was prepared by ball milling for 10 *** effect of the addition of graphene on the activation and hydrogen de/absorption properties of La_(1.7)Pr_(0.3)Mg_(16)Ni alloy was *** result demonstrated that these composite alloys were composed of La_(2)Mg_(17),La_(2)Ni_(3),and Mg_(2)Ni *** saturated hydrogen absorption,it was composed of LaH_(3),Mg_(2)NiH_(4),and MgH_(2)phases,while during the dehydrogenation process,it was composed of LaH_(3),Mg,and Mg_(2)Ni *** addition of graphene can help get a more homogeneous granule after ball milling and accelerate the first activation of dehydrogenation/hydrogen *** hydrogen release activation energy of the alloys first decreases and then increases as the graphene content increases from x=0 wt.%to x=6 wt.%.The minimum activation energy of the composite hydrogen storage alloy is 51.22 kJ mol^(-1) when x=4 wt.%.
The Ordos Basin(OB)in the western part of the North China Craton(NCC),was located at the jointed area of multi-plates and has recorded the Mesozoic tectonic *** tectonic evolution in the Mesozoic is significant to und...
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The Ordos Basin(OB)in the western part of the North China Craton(NCC),was located at the jointed area of multi-plates and has recorded the Mesozoic tectonic *** tectonic evolution in the Mesozoic is significant to understand the tectonic transformation of the northern margin of the *** this work,the detrital zircon and apatite(U-Th)/He chronological system were analyzed in the northern part of the OB,and have provided new evidence for the regional tectonic ***(U-Th)/He chronological data states the weighted ages of 240‒235 Ma,141 Ma with the peak distribution of 244 Ma,219 Ma,173 Ma,147‒132 *** thermal evolution,geochronological data,and regional unconformities have proved four stages of regional tectonic evolution for the OB and its surroundings in the Mesozoic:(1)The Late Permian-Early Triassic;(2)the Late Triassic-Early Jurassic;(3)the Late Jurassic-Early Cretaceous;(4)the Late Cretaceous-Early *** is indicated that the multi-directional convergence from the surrounding tectonic units has controlled the Mesozoic tectonic evolution of the ***-stage tectonic evolution reflected the activation or end of different plate movements and provided new time constraints for the regional tectonic evolution of the NCC in the Mesozoic.
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