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1.
J Nanosci Nanotechnol ; 20(2): 810-818, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383076

RESUMO

Porous MgO nanostructures were synthesized in large-scale by a simple solution combustion method using citric acid and glucose as the fuel. The resulting porous nanostructure powders were characterized by X-ray diffraction (XRD), scanning electronic microscopy (SEM), transmission electron microscopy (TEM), and N2 adsorption-desorption isotherms. The SEM and TEM images demonstrated that the type of fuel used during the combustion synthesis strongly affects the morphology and structure. The use of glucose aggregated the structure with majority particle sizes in the range 3560 nm and a surface area of 40.55 m²g-1, while the use of citric acid results in a large network structure with smaller particle sizes (30-50 nm) and a larger surface area of 53.88 m²g-1. The two samples synthesized from glucose and citric acid exhibited excellent adsorption performance for Congo red with the maximum capacity reaching 1500.98 mg g-1 and 1638.08 mg g-1, respectively. These results indicate that the porous MgO synthesized by the solution combustion is a potential candidate for the removal of pollutant dye in water.

2.
J Org Chem ; 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31469283

RESUMO

A highly efficient palladium-catalyzed Sonogashira coupling of benzylic ammonium salts with terminal alkynes is developed. This strategy provides a facile access to a series of internal alkyne derivatives in moderate to excellent yields via C-N bond cleavage and C(sp3)-C(sp) bond formation. The broad substrate scope and high functional group tolerance make this reaction attractive for organic synthesis.

3.
AIDS ; 33 Suppl 1: S81-S91, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31397726

RESUMO

OBJECTIVES: The Child-Caregiver-Advocacy Resilience (ChildCARE) intervention aims to enhance the psychosocial wellbeing of children affected by parental HIV by providing programing at three levels: child, caregiver, and community. The objective of the current study was to evaluate the intervention's efficacy in improving mental health and parenting outcomes for participating caregivers. DESIGN: A cluster randomized controlled trial was used to evaluate initial efficacy of the intervention. METHODS: A total of 790 caregivers of children affected by parental HIV were recruited from Henan, China. Caregivers and their children were randomly assigned to one-of-four intervention arms (control, child-only, child + caregiver, child + caregiver + community) to evaluate the multiple components of ChildCARE. Those assigned to receive the caregiver intervention participated in five 2-h intervention sessions designed to improve their parenting skills and enhance their ability to cope with daily stressors. Caregivers reported on their mental health and parenting behaviors at baseline, 12, 24, and 36 months, with mixed effect modeling used to examine intervention effects. RESULTS: Caregivers who participated in the intervention reported decreased anxiety and parental stress at 12 months (P < 0.05). Participants also reported increased use of structured parenting skills (i.e., parental demandingness) at 12 and 24 months (P < 0.05). However, by 36 months, they reported significantly lower levels of parental competence (P < 0.01) than those assigned to the control condition. CONCLUSION: Preliminary findings suggest that the caregiving component of ChildCARE yields initial improvements in some key parenting and mental health outcomes. However, the challenges of caring for children affected by HIV are complex and may require more intensive intervention to yield marked, positive changes across key caregiver outcomes.

4.
Ecotoxicol Environ Saf ; 182: 109453, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31349105

RESUMO

Telomeres are DNA-protein structures that protect chromosome ends from degradation and fusion, which are shortened by oxidative stress, for example air pollution including benzene, toluene, Coke Oven Emissions (COEs), and so on. As a biomarker of health and disease, telomere length is associated with cardiovascular, diabetes and cancers. The aim of this study was to estimate the effects of COEs exposure on telomere length and the benchmark dose (BMD) of COEs. A total of 542 coke oven workers and 235 healthy controls without exposure to toxicants were recruited. Quantitative PCR was used to determine the telomere length in human peripheral blood leukocytes DNA. Propensity scoring was used to match coke oven workers to healthy controls. Linear regression models and trend tests were used to the relationship between COEs exposure and telomere length. Telomere length in COEs exposed group 0.764 (0.536, 1.092) was significantly shorter than that in the control group 1.064(0.762, 1.438), (P < 0.001). There were significantly dose-response relationships between COEs exposure and telomere damage with telomere length as a biomarker. A BMDL value lower than the present occupational exposure limits (OELs) of COEs exposure was evaluated using the BMD approach in coke oven workers. Our results suggested that shorter telomere length is related to occupational exposure to COEs and the level of COEs exposure lower than the current national OELs in China and many other countries could induce telomere damage.

5.
Brain Res ; 1718: 252-258, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31004577

RESUMO

An impairment in interference inhibitory control ability has been reported in children with learning disorders (LD), but few studies have examined the neural mechanism of this impairment. This study applied electroencephalogram (EEG) technique to investigate the emotional interference inhibitory control ability in 25 LD children and 22 non-LD controls with face-word emotional Stroop task. Results from behavioral tasks showed that LD children exhibited lower accuracy and longer reaction times. The EEG analysis showed that the non-LD children displayed significant interference effects both in the ERP components, with N2, N450 and SP exhibiting a larger activation in incongruent condition than the congruent condition, and brain oscillation, with early and late alpha demonstrating a larger desynchronization in the incongruent condition compared to the congruent condition. However, all these interference effects were absent in the LD children except the SP component. The present findings seem to indicate that the deficit during emotional interference control ability among children with LD might be due to the impaired attention allocation ability during emotional conflict detection process. Future research is needed to replicate these results and to explore the biochemical mechanisms between the impaired emotional interference inhibitory control ability and impaired attentional control ability.

6.
J Org Chem ; 84(7): 4458-4466, 2019 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-30843394

RESUMO

A robust transition-metal-free one-step strategy for the synthesis of ynamides from sulfonamides and ( Z)-1,2-dichloroalkenes or alkynyl chlorides is presented. This method is not only effective for internal ynamides but also amenable for terminal ynamides. Various functional groups, even the vinyl moiety, are compatible, and thus, this strategy offers the opportunity for further functionalization.

7.
Sci Rep ; 9(1): 2114, 2019 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-30765807

RESUMO

It has long been conjectured that pure-element face-centred cubic (fcc) metals can be transformed into a glassy state by deformation at ultra-high strain rates. However, when an impact force is applied at the nanoscale, deformation-induced melting prevents observations of fcc metal amorphisation. Here we propose a sonication treatment of Ag nanowires (fcc) and confirmed amorphisation induced by high strain rates at bent areas of the Ag nanowires. Owing to the mismatch of the deformation modes between the core and the surface, we observed a diameter related increase of the ductility of Ag nanowires under deformation at ultra-high strain rates generated by sonication. The sonication-prepared amorphous Ag was stable at room temperature. Amorphous Ag at the bent areas was highly reactive and was readily recrystallized under light illumination or vulcanised. Our study verifies the occurrence of high strain rate induced amorphisation in pure fcc MGs and provides a powerful tool for mechanical studies on metal nanomaterials under extremely high strain rates and forces.

8.
Neurosci Lett ; 703: 198-204, 2019 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-30677434

RESUMO

Impairment of facial emotion recognition ability has been reported in deaf children, but few researches have examined the neural mechanism of this impairment. This study applied the electroencephalogram (EEG) technique to investigate the emotion recognition ability in 31 deaf children and 30 hearing controls with facial emotion recognition task. Results from behavioral task showed that deaf children exhibited lower accuracy compared to hearing controls. As for EEG analysis, results showed that deaf children showed diminished activation in the early (N1、P1), middle (N170) and late stages (late positive potential, LPP) compared to hearing controls. In addition, for brain oscillation, alpha band (400-800 ms) also revealed a reduced desynchronization in deaf children. The present findings seem to indicate that the deficit during facial emotion recognition ability among deaf children might be due to the impairments in visual processing, attention and emotional semantic distribution ability during facial emotion recognition processing.

9.
Psychosom Med ; 81(2): 200-208, 2019 Feb/Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30531205

RESUMO

OBJECTIVE: Low socioeconomic status (SES) is one of the most well-established social determinants of health. However, little is known about what can protect the health of individuals (especially children) living in low-SES circumstances. This study explored whether the psychological strategy of "shift-and-persist" protects low-SES children from stress-related physiological risks, as measured through blunted (unhealthy) diurnal cortisol profiles. METHODS: A sample of 645 children (aged 8-15 years) from low-SES backgrounds and having at least one HIV-positive parent completed a battery of psychological scales. Diurnal cortisol assessments included collection of saliva samples four times a day for 3 days, from which three cortisol parameters (cortisol at awakening, cortisol awakening response, and cortisol slope) were derived. RESULTS: Higher levels of shift-and-persist, considered as a single variable, were associated with higher cortisol at awakening (B = 0.0119, SE = 0.0034, p < .001) and a steeper cortisol slope (B = -0.0007, SE = 0.0003, p = .023). These associations remained significant after adjusting for covariates and did not vary by age. In supplementary analyses, where shifting and persisting were treated as separate variables, the interaction between these two coping strategies significantly predicted cortisol at awakening (B = 0.0250, SE = 0.0107, p = .020) and the cortisol slope (B = -0.0022, SE = 0.0011, p = .040), suggesting that the combination of shift-and-persist is important for predicting diurnal cortisol profiles. CONCLUSIONS: Our findings demonstrate that shift-and-persist is associated with healthier diurnal cortisol profiles among socioeconomically disadvantaged children and introduce the possibility that this coping strategy is protective against other stressors, such as those uniquely faced by children in our study (i.e., being affected by parental HIV).

10.
Opt Express ; 26(19): 25031-25036, 2018 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-30469611

RESUMO

An electricity-mediated plasmonic engineering was applied on a single Ag nanowire to engineer its tip for surface-enhanced Raman scattering (SERS). Under this constant photoelectric field treatment, a significant sharpening of the tip and reduction of the surface fluctuation was observed for the Ag nanowire tip via in situ atomic force microscopy. A significant SERS signal enhancement was thus obtained after the tip engineering. The relevant dynamic mechanisms of the tip engineering, including the light-induced plasmonic phase transition and electrostatic force driven flow on the Ag nanowire tip are discussed in detail. It is expected that this type of tip engineering will greatly enhance the signal of single metal nanowire SERS probes and provide new insights into fabrication technologies for metal nanostructures.

11.
Artigo em Inglês | MEDLINE | ID: mdl-30403319

RESUMO

Thioamide substitution has evolved into an important tool for the chemical biology of peptides and proteins. However, exploration of its full potential has been hampered by insufficient synthetic strategies for site-specific introduction of a thioamide bond to a peptide backbone. A novel ynamide-mediated two-step thiopeptide bond formation strategy with easily available monothiocarboxylic acids as the thioacyl donors is described. The α-thioacyloxyenamide intermediates formed from the addition reactions of ynamides and monothiocarboxylic acids are stable and can be purified, characterized and stored. Their appropriate balance between activity and stability enables them to act as effective thioacylating reagents to afford thiopeptide bonds under mild reaction conditions. Notorious issues such as racemization/epimerization and the use of toxic and noxious thionating reagents, which have long plagued thiopeptide synthesis, have been addressed. Some side chain functional groups of amino acids such as -OH, -CONH2, and the NH of indole are tolerated, rendering their protection during thiopeptide synthesis unnecessary. Importantly, the modular nature of this strategy guarantees the site-specific incorporation of a thioamide bond to peptide backbone in both the solution and solid phase.

12.
Artigo em Inglês | MEDLINE | ID: mdl-30222529

RESUMO

OBJECTIVE: To evaluate the surgical outcomes of single-site laparoscopic percutaneous extraperitoneal closure (SLPEC) and modified transumbilical two-port laparoscopic suturing (M-TTLS) of the hernia sac for the treatment of pediatric inguinal hernia (PIH) and determine whether one approach was superior to another. METHODS: From January 2014 to June 2017, a total of 599 children had undergone SLPEC or M-TTLS in our department. SLPEC and M-TTLS were the most frequently performed single-site laparoscopic procedures for PIH in our department, which represented the extraperitoneal and intraperitoneal approaches, respectively. All patients were followed up at the out-patients' clinics and the medical records were reviewed with respect to all operative outcomes. RESULTS: There were 412 patients undergoing SLPEC and 187 patients undergoing M-TTLS, of which 358 hernias were on the right side, 172 on the left and 69 bilaterally. Two hundred and thirty-one unilateral hernias with contralateral patent processus vaginalis underwent contralateral repair at the same session. Mean operation time was 10.81 minutes in unilateral repair and 17.00 minutes in bilateral repairs, respectively. The perioperative complications included minor extraperitoneal hematoma in four (0.44%) patients, recurrence in one (0.11%), hydrocele in five (0.56%), and contralateral metachronous inguinal hernia in three (1.00%). No other complication developed in either group. There was no significant difference of complications between the two approaches except for the longer operation time in M-TTLS. CONCLUSIONS: Both SLPEC and M-TTLS were the safe and effective methods for PIH. The complications were comparable for M-TTLS and SLPEC, but operation time was significantly longer in M-TTLS than in SLPEC.

13.
Org Lett ; 20(18): 5688-5691, 2018 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-30168334

RESUMO

An efficient intermolecular trans-selective ß-hydroamidation of ynamides to furnish a series of ( Z)-ethene-1,2-diamide derivatives with excellent regio- and stereo-selectivities is described. The trans-ß-addition reactions have been illustrated for a wide range of substrates and proceeded under basic reaction conditions using readily available materials in the absence of a transition-metal catalyst. The synthetic approach to these novel ( Z)-ethene-1,2-diamide derivatives paves the way for further exploration of their synthetic application.

14.
Artigo em Inglês | MEDLINE | ID: mdl-30260593

RESUMO

BACKGROUND: Sociometer theory posits that self-esteem is a subjective monitor of the quality of one's interpersonal relationships. When people feel excluded by others, they may have negative relational evaluation about themselves-low self-esteem. In the present study, we hypothesised and tested that feelings of loneliness among children and adolescents affected by parental HIV would decrease their self-esteem over time; moreover, low self-esteem would intensify feelings of loneliness. METHODS: We utilised longitudinal data from a sample of children and adolescents affected by parental HIV to estimate the reciprocal effects between self-esteem and loneliness over time. The sample included 195 children and early adolescents affected by parental HIV (age range 7-15, Mage = 10.62, 82 females) who served as a control group in a large intervention study on psychological well-being. Seven waves of longitudinal panel data were collected from participants in three years. RESULTS: In cross-lagged panel models that tested the reciprocal effects of loneliness and self-esteem, loneliness predicted decreased levels of self-esteem over time; in addition, low self-esteem predicted increased levels of loneliness over time. CONCLUSIONS: These findings support sociometer theory and suggest that loneliness is a risk factor for children's and adolescents' self-esteem. The implications for improving vulnerable children's and adolescents' psychological well-being are discussed.

15.
Psychoneuroendocrinology ; 97: 174-181, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30036795

RESUMO

The hypothalamic-pituitary-adrenal (HPA) axis activity has been demonstrated as one of the physiological mechanisms underlying the long-lasting effects of peer victimization on physical and mental health. However, the mechanisms linking peer victimization to dysregulations of HPA axis activity remain inadequately understood. The present study examined the potential mediating role of emotional regulation in the association between peer victimization and HPA axis activity in a large community-based sample of 645 children affected by parental HIV (Mage = 10.67 years, ranging from 8 to 15 years old). The three-level growth curve model revealed that higher peer victimization was associated with lower emotional regulation, which in turn was related to lower cortisol at awakening and more blunted diurnal slopes in girls, but not in boys. The findings highlight the protective effect of emotional regulation in relation to HPA axis activity in victimized children, particularly in girls.

16.
J Org Chem ; 83(15): 8710-8715, 2018 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-29978707

RESUMO

An efficient palladium-catalyzed Suzuki coupling of 1,1-diarylmethyl-trimethylammonium triflates with arylboronic acids is reported. This reaction offers a novel approach to triarylmethane derivatives in good to excellent yields with the palladium-catalyzed C-N bond cleavage as the key feature. Broad substrate scope regarding both reaction partners are observed. Moreover, reactive functional groups such as vinyl and formyl groups are conserved in this transformation.

17.
Environ Sci Pollut Res Int ; 25(23): 22998-23008, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29858998

RESUMO

In this study, the effect of Fe3+, Fe2+, and Mn2+ dose, solution pH, reaction temperature, background water matrix (i.e., inorganic anions, cations, and natural organic matters (NOM)), and the kinetics and mechanism for the reaction system of Fe(VI)/Fe3+, Fe(VI)/Fe2+, and Fe(VI)/Mn2+ were investigated systematically. Traces of Fe3+, Fe2+, and Mn2+ promoted the DCF removal by Fe(VI) significantly. The pseudo-first-order rate constant (kobs) of DCF increased with decreasing pH (9-6) and increasing temperature (10-30 °C) due to the gradually reduced stability and enhanced reactivity of Fe(VI). Cu2+ and Zn2+ ions evidently improved the DCF removal, while CO32- restrained it. Besides, SO42-, Cl-, NO3-, Mg2+, and Ca2+ almost had no influence on the degradation of DCF by Fe(VI)/Fe3+, Fe(VI)/Fe2+, and Fe(VI)/Mn2+ within the tested concentration. The addition of 5 or 20 mg L-1 NOM decreased the removal efficiency of DCF. Moreover, Fe2O3 and Fe(OH)3, the by-products of Fe(VI), slightly inhibited the DCF removal, while α-FeOOH, another by-product of Fe(VI), showed no influence at pH 7. In addition, MnO2 and MnO4-, the by-products of Mn2+, enhanced the DCF degradation due to catalysis and superposition of oxidation capacity, respectively. This study indicates that Fe3+ and Fe2+ promoted the DCF removal mainly via the self-catalysis for Fe(VI), and meanwhile, the catalysis of Mn2+ and the effect of its by-products (i.e., MnO2 and MnO4-) contributed synchronously for DCF degradation. Graphical abstract ᅟ.

18.
Braz J Microbiol ; 49 Suppl 1: 166-177, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29898867

RESUMO

In the previous study, we used genome shuffling to improve fengycin production of the original strain Bacillus amyloliquefaciens ES-2-4. After two rounds of genome shuffling, a high-yield recombinant FMB72 strain that exhibited 8.30-fold increase in fengycin production was obtained. In this study, comparative proteomic analysis of the parental ES-2-4 and genome-shuffled FMB72 strains was conducted to examine the differentially expressed proteins. In the shuffled strain FMB72, 50 differently expressed spots (p<0.05) were selected to be excised and analyzed using Matrix-Assisted Laser Desorption/Ionization Time of Flight/Time of Flight Mass Spectrometry, and finally 44 protein spots were confidently identified according to NCBI database. According to clusters of orthologous groups (COG) functional category analysis and related references, the differentially expressed proteins could be classified into several functional categories, including proteins involved in metabolism, energy generation and conversion, DNA replication, transcription, translation, ribosomal structure and biogenesis, cell motility and secretion, signal transduction mechanisms, general function prediction. Of the 44 identified proteins, signaling proteins ComA and Spo0A may positively regulate fengycin synthesis at transcriptional level. Taken together, the present study will be informative for exploring the exact roles of ComA and Spo0A in fengycin synthesis and explaining the molecular mechanism of fengycin synthesis.

19.
Nanoscale ; 10(12): 5489-5495, 2018 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-29511751

RESUMO

This study reports on a self-powered mechanoluminescent flexible film that converts human movement into green, yellow, and white light that are visible to the naked eye. The film is simply a highly porous composite material that was prepared using a piezoelectric polymer and ZnS luminescent powders. The highly effective mechanoluminescence capabilities stem from both the film's porous structure and the strong interactions between poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and ZnS particles. The porous film's sensitivity helps the conversion of mechanical disturbances into electrical energies and induces the electroluminescence of ZnS particles. The particle-film interactions induced a high ß-phase, which is the most effective piezoelectric phase, in the PVDF-HFP film. Similar to polymeric materials, the composite film is highly processable and can be written into arbitrary shapes or patterns using a pipette or stamping techniques. Finger rubbing or ultrasonication makes the mechanoluminescence patterns readable. This composite mechanoluminescent film provides high potential for future applications in electronic skins, smart electronics, and information encryption techniques.

20.
Mikrochim Acta ; 185(2): 131, 2018 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-29594579

RESUMO

The authors report that cobalt oxyhydroxide (CoOOH) nanoflakes possess intrinsic oxidizing ability to directly oxidize 3,3',5,5'-tetramethylbenzidine (TMB) to form a blue colored product (oxTMB) even in the absence of H2O2 and oxygen. In the presence of ascorbic acid (AA), less of the blue product is formed because AA reduces oxTMB. These findings constitute a new scheme for colorimetric detection of AA. Absorbance, best measured at 652 nm, linearly drops in the 10 nM to 1 µM AA concentration range, and the limit of detection is 5 nM (at an S/N ratio of 3). The reaction is complete within <5 s and highly selective. A strip test has been designed for fast and on-spot visual detection of AA. The method was applied to the direct estimation of AA in the microdialysate of brain, and also in soft drink samples. The strip test is considered to be a promising tool for the rapid screening of AA in brain and commercial samples. Graphic abstract Schematic of the CoOOH-TMB colorimetric system that exhibits a high selectivity for ascorbic acid (AA). A strip test has been designed for fast and on-spot visual detection of AA.

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