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1.
Small ; 20(7): e2306622, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37806765

RESUMO

Lithium-metal batteries (LMBs) are considered the "holy grail" of the next-generation energy storage systems, and solid-state electrolytes (SSEs) are a kind of critical component assembled in LMBs. However, as one of the most important branches of SSEs, polymer-based electrolytes (PEs) possess several native drawbacks including insufficient ionic conductivity and so on. Click chemistry is a simple, efficient, regioselective, and stereoselective synthesis method, which can be used not only for preparing PEs with outstanding physical and chemical performances, but also for optimizing the stability of solid electrolyte interphase (SEI) layer and elevate the cycling properties of LMBs effectively. Here it is primarily focused on evaluating the merits of click chemistry, summarizing its existing challenges and outlining its increasing role for the designing and fabrication of advanced PEs. The fundamental requirements for reconstructing artificial SEI layer through click chemistry are also summarized, with the aim to offer a thorough comprehension and provide a strategic guidance for exploring the potentials of click chemistry in the field of LMBs.

2.
Bull World Health Organ ; 101(10): 637-648, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37772197

RESUMO

Objective: To evaluate the precision and dependability of road traffic mortality data recorded in the World Health Organization Mortality Database and investigate how uncorrected data influence vital mortality statistics used in traffic safety programmes worldwide. Methods: We assessed country and territory-specific data quality from 2015 to 2020 by calculating the proportions of five types of nonspecific cause of death codes related to road traffic mortality. We compared age-adjusted road traffic mortality and changes in the average annual mortality rate before and after correcting the deaths with nonspecific codes. We generated road traffic mortality projections with both corrected and uncorrected codes, and redistributed the data using the proportionate method. Findings: We analysed data from 124 countries and territories with at least one year of mortality data from 2015 to 2020. The number of countries and territories reporting more than 20% of deaths with ill-defined or unknown cause was 2; countries reporting injury deaths with undetermined intent was 3; countries reporting unspecified unintentional injury deaths was 21; countries reporting unspecified transport crash deaths was 3; and countries reporting unspecified unintentional road traffic deaths was 30. After redistributing deaths with nonspecific codes, road traffic mortality changed by greater than 50% in 7% (5/73) to 18% (9/51) of countries and territories. Conclusion: Nonspecific codes led to inaccurate mortality estimates in many countries. We recommend that injury researchers and policy-makers acknowledge the potential pitfalls of relying on raw or uncorrected road traffic mortality data and instead use corrected data to ensure more accurate estimates when improving road traffic safety programmes.


Assuntos
Estatísticas Vitais , Ferimentos e Lesões , Humanos , Acidentes de Trânsito , Bases de Dados Factuais , Organização Mundial da Saúde , Registros
3.
BMC Public Health ; 23(1): 531, 2023 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-36941599

RESUMO

BACKGROUND: Interactive and experiential learning programs have proven effective to teach children safety and prevent child unintentional injury. However, previously-published programs were designed primarily to address safety concerns of children living in urban, well-resourced areas, and therefore might be less effective or economically infeasible to distribute to children in resource-limited areas, such as those living in rural areas or underdeveloped regions. This proposed study will evaluate the effectiveness of teaching children safety lessons to rural preschoolers in China through the preschool-based Safety Experience Room intervention that was developed based on relevant theories, the lessons of previous intervention research, the characteristics of child injuries in underdeveloped rural areas, and the needs and circumstances of rural families and preschools in China. The study will also evaluate the cost-effectiveness of delivering the program. METHODS AND ANALYSIS: A single-blinded, 12-month follow-up, parallel-group cluster randomized controlled trial with a 1:1 allocation ratio will be implemented in two selected counties. In total, at least 2378 rural preschoolers aged 3-6 years old will be recruited from 12 preschools, 6 in Yang County and 6 in Shicheng County. Clusters will be randomized at the preschool level and allocated to the control group (routine school-based education) or the intervention group (routine school-based education plus the Safety Experience Room education). External support strategies will be implemented by local partners to minimize attrition. Data collection will be conducted at baseline and then every 3 months during a 12-month follow-up time period. Intention-to-treat (ITT) data analysis will be used. Generalized estimation equations (GEE) will evaluate the effectiveness of the program and generalized cost-effectiveness analysis (GCEA) will evaluate the cost-effectiveness of it. A per-protocol (PP) sensitivity analysis will assess the robustness of ITT results. Subgroup analyses will be performed to evaluate the impact of socio-demographic factors on the intervention effect, following the same strategies as the primary analyses. DISCUSSION: The newly-designed Safety Experience Room program is expected to be feasible, effective, and financially beneficial. If these hypotheses prove true, we will take steps to disseminate the program to rural preschools across China. TRIAL REGISTRATION: Chinese Clinical Trial Registry ( http://www.chictr.org.cn ), CHiCTR2000038025, registered on 8 September 2020.


Assuntos
Instituições Acadêmicas , Criança , Humanos , Pré-Escolar , Escolaridade , China , Ensaios Clínicos Controlados Aleatórios como Assunto
4.
BMC Geriatr ; 22(1): 72, 2022 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-35073870

RESUMO

BACKGROUND: Several studies have assessed the reporting quality of all-cause mortality data from the WHO Mortality Database, but little is known about coding quality and its impact on elderly unintentional fall mortality data worldwide. We aimed to assess the coding quality of deaths and its impact on elderly unintentional fall mortality. METHODS: Using data from the WHO Mortality Database, 1990-2019, we calculated the number of countries/territories that had mortality data in the database, and the proportion of deaths with five types of problematic codes based on the 10th International Classification of Disease (unspecified deaths, injury deaths with undetermined intent, unspecified unintentional injury, unintentional falls with unspecified mechanism, unintentional falls with unknown occurrence place). We estimated age-adjusted unintentional fall mortality before and after correcting problematic codes. RESULTS: Only 64% (124/194) of WHO member states had at least 1 year of mortality data in the database during 1990-2019, and data unavailability was more common for underdeveloped countries/territories than for developed countries/territories. Coding quality was poor for many countries/territories. Among the study years when countries/territories possessed mortality data, 80, 53, 51, and 63% had a proportion of unintentional fall deaths with unspecified mechanism over 50% in low-income, lower middle-income, upper middle-income, and high-income countries/territories, respectively; comparable proportions for unintentional fall deaths with unknown occurrence place were 100, 42, 71, and 62%. Among the 94 countries/territories having mortality data, problematic codes caused a relative mortality difference ≥ 50% in 59 countries/territories (63%). After correcting problematic codes, 5 of 55 countries/territories with data witnessed a reverse in mortality changes between 2005 and 2015. Among the 82 countries/territories with mortality data for 5 or more years, 18 countries/territories (22%) experienced a directional reverse in linear regression coefficient. CONCLUSIONS: The availability and coding quality of global data related to elderly unintentional fall mortality was poor between 1990 and 2019. When data are available, varying coding quality across countries/territories and over time have a substantial impact on mortality estimates and mortality comparisons. Global agencies plus each individual government should be aware of the importance of collecting and sharing high-quality mortality data, and take action to improve data quality for inclusion in the WHO Mortality Database.


Assuntos
Classificação Internacional de Doenças , Idoso , Causas de Morte , Bases de Dados Factuais , Humanos , Estudos Retrospectivos , Organização Mundial da Saúde
5.
Inorg Chem ; 60(5): 3410-3417, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33560831

RESUMO

We report herein a series of Cp*Ir complexes containing a rigid 8-aminoquinolinesulfonamide moiety as highly efficient catalysts for the dehydrogenation of formic acid (FA). The complex [Cp*Ir(L)Cl] (HL = N-(quinolin-8-yl)benzenesulfonamide) displayed a high turnover frequency (TOF) of 2.97 × 104 h-1 and a good stability (>100 h) at 60 °C. Comparative studies of [Cp*Ir(L)Cl] with the rigid ligand and [Cp*Ir(L')Cl] (HL' = N-propylpypridine-2-sulfonamide) without the rigid aminoquinoline moiety demonstrated that the 8-aminoquinoline moiety could dramatically enhance the stability of the catalyst. The electron-donating ability of the N,N'-chelating ligand was tuned by functionalizing the phenyl group of the L ligand with OMe, Cl, and CF3 to have a systematical perturbation of the electronic structure of [Cp*Ir(L)Cl]. Experimental kinetic studies and density functional theory (DFT) calculations on this series of Cp*Ir complexes revealed that (i) the electron-donating groups enhance the hydrogen formation step while slowing down the ß-hydride elimination and (ii) the electron-withdrawing groups display the opposite effect on these reaction steps, which in turn leads to lower optimum pH for catalytic activity compared to the electron-donating groups.

6.
BMC Public Health ; 21(1): 2137, 2021 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-34801006

RESUMO

BACKGROUND: Compared to urban children, children living in rural areas of most countries, including China, are at higher risk of suffering unintentional injuries. Most proven injury prevention interventions, however, are rarely implemented in rural China due to lack of resources. Mobile health interventions are low-cost and easy-to-implement, facilitating implementing injury prevention in resource-limited areas (e.g., rural areas). This study is designed and implemented to examine the effectiveness of an app-based intervention for unintentional injury prevention among rural preschoolers in China. METHODS: A single-blind, 18-month, parallel-group cluster randomized controlled trial with 1:1 allocation ratio will be implemented in 2 rural areas of China (Yang County, Shaanxi Province, and Shicheng County, Jiangxi Province). In total, at least 3508 rural caregivers of preschoolers aged 3-6 years old who own a smartphone will be recruited from 24 preschools. Clusters will be randomized at the preschool level and allocated to the control group (receiving routine school-based education plus app-based parenting education excluding unintentional injury prevention) or the intervention group (receiving routine school-based education plus app-based parenting education including unintentional injury prevention). External support strategies will be adopted by local partners to minimize user fatigue, non-compliance, and attrition. Data collection will be conducted at baseline and then every 3 months during the 18-month follow-up time period. Intention-to-treat data analysis will be implemented. Missing values will be imputed by using the Expectation Maximization algorithm. Generalized estimating equation will test the overall effectiveness of the app-based intervention. A per-protocol sensitivity analysis will be conducted to test the robustness of results. Subgroup analyses will follow the strategies for primary analyses. The primary outcome measure is the incidence rate of unintentional injury among preschoolers during the study period. Secondary outcome measures comprise longitudinal changes in caregiver's attitudes, caregiver-reported supervision behaviors, and caregiver-assessed home environment safety surrounding child unintentional injury prevention in the last week using a standardized audit instrument. DISCUSSION: The app-based intervention is expected to be feasible and effective over the 18-month intervention period. If the app is demonstrated effective as hypothesized, we will initiate processes to generalize and popularize it broadly to rural child caregivers across China. TRIAL REGISTRATION: ChiCTR2000037606 , registered on August 29, 2020.


Assuntos
Cuidadores , Aplicativos Móveis , Criança , Pré-Escolar , China/epidemiologia , Ambiente Domiciliar , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Método Simples-Cego
7.
J Med Internet Res ; 23(1): e21636, 2021 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-33512318

RESUMO

BACKGROUND: Mobile health (mHealth) interventions offer great potential to reach large populations and improve public health. However, high attrition rates threaten evaluation and implementation of mHealth intervention studies. OBJECTIVE: We explored factors associated with attrition of study participants in an mHealth randomized controlled trial (RCT) evaluating an intervention to reduce unintentional child injury risk in China. METHODS: The cluster RCT compared two groups of an app-based intervention for caregivers of 3-6-year-old children (Bao Hu San). The intervention group received unintentional child injury and parenting education, whereas only parenting education was implemented in the control group. The trial included 2920 study participants in Changsha, China, and lasted 6 months. Data on participant engagement (using the app) were collected electronically throughout the 6-month period. Associations between participant attrition and demographic characteristics, and between attrition and intervention engagement were tested and quantified separately for the intervention and control groups using the adjusted odds ratio (aOR) based on generalized linear mixed models. RESULTS: In total, 2920 caregivers from 20 eligible preschools participated, with 1510 in the intervention group and 1410 in the control group. The 6-month attrition rate differed significantly between the two groups (P<.001), at 28.9% (437/1510) in the intervention group and 35.7% (503/1410) in the control group. For the intervention group, the only significant predictor of attrition risk was participants who learned fewer knowledge segments (aOR 2.69, 95% CI 1.19-6.09). For the control group, significant predictors of attrition risk were lower monthly login frequency (aOR 1.48, 95% CI 1.00-2.18), learning fewer knowledge segments (aOR 1.70, 95% CI 1.02-2.81), and shorter learning durations during app engagement (aOR 2.39, 95% CI 1.11-5.15). Demographic characteristics were unrelated to attrition. CONCLUSIONS: Engagement in the app intervention was associated with participant attrition. Researchers and practitioners should consider how to best engage participants in app-based interventions to reduce attrition. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR-IOR-17010438; http://www.chictr.org.cn/showproj.aspx?proj=17376. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1186/s12889-018-5790-1.


Assuntos
Saúde da Criança/tendências , Análise de Dados , Aplicativos Móveis/normas , Ferimentos e Lesões/prevenção & controle , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Telemedicina
8.
J Transl Med ; 17(1): 177, 2019 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-31133033

RESUMO

BACKGROUND: Kidney renal clear cell carcinoma (KIRC) is the most common type of kidney cancer in adults, and it is responsible for approximately 90-95% of cases. Although extensive evidence has suggested that many immune- and inflammation-related genes could serve as effective biomarkers in KIRC, the potential associations among immune-, inflammation- and KIRC-related genes has not been sufficiently understood. METHODS: Here, we integrated multiple levels of data to construct an immune-, inflammation- or KIRC-directed neighbour network (IIKDN network) and a KIRC-related gene-directed network (KIRCD network). RESULTS: Our analysis suggested that immune- and inflammation-related genes in the network have special topological characteristics and expression patterns related to KIRC. We further identified five core clusters that showed a tighter network structure and stronger correlation of expression from the KIRCD network. Specifically, multiple-level molecular characteristics were systematically portrayed, including somatic mutation, copy-number variant and DNA methylation for the genes in five core clusters. We discovered that the genes showed strong correlation with respect to the expression and methylation levels in these five core clusters. These five core clusters could become special prognostic biomarkers for KIRC, and functional analysis showed that they were associated with activation of the immune and inflammation systems and cancer progression. CONCLUSIONS: Our findings highlighted the novel role of the immune and inflammation genes in KIRC.


Assuntos
Biomarcadores Tumorais/isolamento & purificação , Carcinoma de Células Renais/genética , Biologia Computacional/métodos , Imunidade/genética , Inflamação/genética , Neoplasias Renais/genética , Integração de Sistemas , Adulto , Biomarcadores Tumorais/genética , Carcinoma de Células Renais/diagnóstico , Carcinoma de Células Renais/patologia , Metilação de DNA , Bases de Dados Genéticas , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Genômica/métodos , Humanos , Neoplasias Renais/diagnóstico , Neoplasias Renais/patologia , Metabolômica/métodos , Fenômica/métodos , Prognóstico , Mapas de Interação de Proteínas
9.
Inorg Chem ; 54(11): 5114-23, 2015 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-25691331

RESUMO

The catalytic cycle for the production of formic acid by CO2 hydrogenation and the reverse reaction have received renewed attention because they are viewed as offering a viable scheme for hydrogen storage and release. In this Forum Article, CO2 hydrogenation catalyzed by iridium complexes bearing sophisticated N^N-bidentate ligands is reported. We describe how a ligand containing hydroxy groups as proton-responsive substituents enhances the catalytic performance by an electronic effect of the oxyanions and a pendent-base effect through secondary coordination sphere interactions. In particular, [(Cp*IrCl)2(TH2BPM)]Cl2 (Cp* = pentamethylcyclopentadienyl; TH2BPM = 4,4',6,6'-tetrahydroxy-2,2'-bipyrimidine) enormously promotes the catalytic hydrogenation of CO2 in basic water by these synergistic effects under atmospheric pressure and at room temperature. Additionally, newly designed complexes with azole-type ligands were applied to CO2 hydrogenation. The catalytic efficiencies of the azole-type complexes were much higher than that of the unsubstituted bipyridine complex [Cp*Ir(bpy)(OH2)]SO4. Furthermore, the introduction of one or more hydroxy groups into ligands such as 2-pyrazolyl-6-hydroxypyridine, 2-pyrazolyl-4,6-dihydroxypyrimidine, and 4-pyrazolyl-2,6-dihydroxypyrimidine enhanced the catalytic activity. It is clear that the incorporation of additional electron-donating functionalities into proton-responsive azole-type ligands is effective for promoting further enhanced hydrogenation of CO2.

10.
Phys Chem Chem Phys ; 16(24): 11976-87, 2014 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-24549266

RESUMO

Catalytic water oxidation has been investigated using five iridium complexes as precatalysts and NaIO4 as an oxidant at various pH conditions. An increase in the activity of all complexes was observed with increasing pH. A detailed analysis of spectroscopic data together with O2-evolution experiments using Cp*Ir(6,6'-dihydroxy-2,2'-bipyridine)(OH2)(2+) as a precatalyst indicate that the high catalytic activity is closely connected with transient species (A) that exhibits an absorption band at λmax 590 nm. The formation of this active form is strongly dependent on reaction conditions, and the species was distinctly observed using a small excess of periodate. However, another species absorbing at 600 nm (B), which seems to be a less active catalyst, was also observed and was more prominent at high oxidant concentration. Dynamic light scattering analysis and transmission electron microscopy have identified species B as 120 nm nanoparticles. The ultrafiltration method has revealed that species A can be attributed to particles with size in the range of 0.5­2 nm, possibly small IrOx clusters similar to those described previously by Harriman and co-workers (J. Phys. Chem., 1991, 95, 616­621).


Assuntos
Irídio/química , Compostos Organometálicos/química , Água/química , Catálise , Cinética , Oxirredução , Espectroscopia de Prótons por Ressonância Magnética , Espectrofotometria Ultravioleta
11.
Dalton Trans ; 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-39171620

RESUMO

The catalytic hydrogenation of carbon dioxide to formate is of great interest due to its significant role in CO2 utilization. In this study, a novel heterogeneous Ru(III) catalyst was prepared by immobilizing RuCl3 on a porous organic polymer (POP) obtained from 1,4-phthalaldehyde (PTA) and 4,4'-biphenyldicarboxaldehyde (BPDA) with melamine. A copolymerization strategy utilizing monomers of varying lengths was employed to prepare the POP-supported Ru catalyst with adjustable porosity. The optimization of the framework porosity resulted in enhanced CO2 affinity, accelerated mass transfer, and a remarkable enhancement in catalytic activity. A high turnover number (TON) of 2458 was achieved for the CO2 hydrogenation to formate in 2 h with catalyst Cat-3 under 3 MPa (CO2/H2 = 1 : 1) at 120 °C in 1 M Et3N aqueous solution. Moreover, the Cat-3 demonstrated good recyclability and was able to be reused for five consecutive runs, resulting in a high total TON of 9971.

12.
Inorg Chem ; 52(21): 12576-86, 2013 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-24131038

RESUMO

New water-soluble pentamethylcyclopentadienyl cobalt(III) complexes with proton-responsive 4,4'- and 6,6'-dihydroxy-2,2'-bipyridine (4DHBP and 6DHBP, respectively) ligands have been prepared and were characterized by X-ray crystallography, UV-vis and NMR spectroscopy, and mass spectrometry. These cobalt(III) complexes with proton-responsive ligands predominantly exist in their deprotonated [Cp*Co(DHBP-2H(+))(OH2)] forms with stronger electron-donating properties in neutral and basic solutions, and are active catalysts for CO2 hydrogenation in aqueous bicarbonate media at moderate temperature under a total 4-5 MPa (CO2:H2 1:1) pressure. The cobalt complexes containing 4DHBP ligands ([1-OH2](2+) and [1-Cl](+), where 1 = Cp*Co(4DHBP)) display better thermal stability and exhibit notable catalytic activity for CO2 hydrogenation to formate in contrast to the catalytically inactive nonsubstituted bpy analogues [3-OH2](2+) (3 = Cp*Co(bpy)). While the catalyst Cp*Ir(6DHBP)(OH2)(2+) in which the pendent oxyanion lowers the barrier for H2 heterolysis via proton transfer through a hydrogen-bonding network involving a water molecule is remarkably effective (ACS Catal. 2013, 3, 856-860), cobalt complexes containing 6DHBP ligands ([2-OH2](2+) and [2-Cl](+), 2 = Cp*Co(6DHBP)) exhibit lower TOF and TON for CO2 hydrogenation than those with 4DHBP. The low activity is attributed to thermal instability during the hydrogenation of CO2 as corroborated by DFT calculations.


Assuntos
Dióxido de Carbono/química , Cobalto/química , Compostos Organometálicos/química , Catálise , Técnicas de Química Sintética , Cristalografia por Raios X , Formiatos , Hidrogenação , Ligantes , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Compostos Organometálicos/síntese química , Prótons , Soluções , Água/química
13.
J Sep Sci ; 36(4): 752-7, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23355368

RESUMO

8-Hydroxy-2'-deoxyguanosine (8-OHdG) is a sensitive biomarker for DNA oxidative damage. However, its determination in human urine is confounded by trace level and complex matrix. In this study, a new configuration of on-line solid phase microextraction coupled to high performance liquid chromatography-ultraviolet detection was established with molecularly imprinted monolithic column as extraction sorbent. The tailor made monolith exhibited high extraction efficiency with the enrichment factor 101.84 for 8-OHdG owing to its special porous structure and inherent selectivity. Under optimal condition, appreciable sensitivity had been achieved for this incorporation with limit of detection 2.04 nmol/L (S/N = 3) and limit of quantification 7.12 nmol/L (S/N = 10), respectively. Precise determination with wide range linearity (0.007-5.00 µmol/L) afforded a practical alternative in urinary 8-OHdG analysis and 107 different subjects had been successfully analyzed. This newly developed method embodied useful prospect for the investigation of DNA oxidative damage with less expense, convenient maintenance and ease of operation.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Desoxiguanosina/urina , Polímeros/química , Microextração em Fase Sólida/métodos , Adsorção , Cromatografia Líquida de Alta Pressão/instrumentação , Desoxiguanosina/isolamento & purificação , Humanos , Impressão Molecular , Polímeros/síntese química , Microextração em Fase Sólida/instrumentação
14.
Org Lett ; 25(40): 7344-7348, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37791683

RESUMO

A visible-light-driven, photocatalyst-free, air-promoted, α-substituted reaction of amines with varying nucleophiles is described. The amine substrate aggregates formed in situ through physical π-π stacking by H2O regulation in organic solvent can absorb visible light and then generate iminium ion intermediates, which undergo nucleophilic substitution reactions with varying nucleophiles to afford α-substituted amines. This reaction features catalyst-free, good functional group tolerance, simple operation procedure, and green reaction conditions.

15.
Chemistry ; 18(30): 9397-404, 2012 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-22718518

RESUMO

Deuterated compounds have received increasing attention in both academia and industrial fields. However, preparations of these compounds are limited for both economic and practical reasons. Herein, convenient generation of deuterium gas (D(2)) and the preparation of deuterated compounds on a laboratory scale are demonstrated by using a half-sandwich iridium complex with 4,4'-dihydroxy-2,2'-bipyridine. The "umpolung" (i.e., reversal of polarity) of a hydrogen atom of water was achieved in consecutive reactions, that is, a cationic H(+)/D(+) exchange reaction and anionic hydride or deuteride transfer, under mild conditions. Selective D(2) evolution (purity up to 89 %) was achieved by using HCO(2)H as an electron source and D(2)O as a deuterium source; a rhodium analogue provided HD gas (98 %) under similar conditions. Furthermore, pressurized D(2) (98 %) without CO gas was generated by using DCO(2)D in D(2)O in a glass autoclave. Transfer deuterogenation of ketones gave α-deuterated alcohols with almost quantitative yields and high deuterium content by using HCO(2)H in D(2)O. Mechanistic studies show that the H(+)/D(+) exchange reaction in the iridium hydride complex was much faster than ß-elimination and hydride (deuteride) transfer.


Assuntos
Monóxido de Carbono/química , Deutério/química , Formiatos/química , Irídio/química , Catálise
17.
ACS Nano ; 16(4): 5515-5528, 2022 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-35352555

RESUMO

Nearly half of pregnancies worldwide are unintended mainly due to failure of contraception, resulting in negative effects on women's health. Male contraception techniques, primarily condoms and vasectomy, play a crucial role in birth control, but cannot be both highly effective and reversible at the same time. Herein, an ultrasound (US)-induced self-clearance hydrogel capable of real-time monitoring is utilized for in situ injection into the vas deferens, enabling effective contraception and noninvasive recanalization whenever needed. The hydrogel is composed of (i) sodium alginate (SA) conjugated with reactive oxygen species (ROS)-cleavable thioketal (SA-tK), (ii) titanium dioxide (TiO2), which can generate a specific level of ROS after US treatment, and (iii) calcium chloride (CaCl2), which triggers the formation of the hydrogel. For contraception, the above mixture agents are one-time injected into the vas deferens, which can transform from liquid to hydrogel within 160 s, thereby significantly physically blocking the vas deferens and inhibiting movability of sperm. When fertility is needed, a noninvasive remedial ultrasound can make TiO2 generate ROS, which cleaves SA-tK to destroy the network of the hydrogel. Owing to the recanalization, the refertility rate is restored to 100%. Meanwhile, diagnostic ultrasound (D-US, 22 MHz) can monitor the occlusion and recanalization process in real-time. In summary, the proposed hydrogel contraception can be a reliable, safe, and reversible male contraceptive strategy that addresses an unmet need for men to control their fertility.


Assuntos
Hidrogéis , Sêmen , Gravidez , Masculino , Feminino , Humanos , Espécies Reativas de Oxigênio , Anticoncepção/métodos , Ultrassonografia
18.
Mol Med Rep ; 23(3)2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33655334

RESUMO

The formation and physicochemical properties of kidney stones (KSs) are closely associated with diet. In view of the differences in ethnicity and dietary composition between Chinese and Western populations, the present study aimed to investigate the association between intestinal dysbacteriosis and KSs in China. The current study examined the differences in intestinal microbes between the KS disease (KSD) and the healthy control (HLT) groups, and statistically significant differences based on 16s rRNA gene amplicons were identified using a Student's t­test or one­way ANOVA. In addition, the calcium oxalate KS (COKS), uric acid KS (UAKS) and carbonate apatite KS(CCKS) groups were compared with a non­parametric statistical test. Determination of bacterial abundance was performed via the analysis of 16s rRNA marker gene sequences using next­generation sequencing. Firmicutes (F) and Bacteroides (B) levels were significantly higher in the KSD group compared with the HLT group (B/F=0.67 vs. 0.08; P<0.001), as were the overall levels of B (6.19­fold higher compared with the HLT group; 22.2 vs. 3.6%; P<0.001). The Prevotella­9 abundance levels in the KSD group were 4.65­fold higher compared with those in the HLT group (8.8 vs. 1.9%; P<0.001). The levels of Blautia and Lachnoclostridium were significantly decreased in the KSD group (13.3 vs. 6.0%; and 5.0 vs. 7.9%; both P<0.05). Moreover, Prevotella­9 levels were higher in non­calciferous KSs (UAKS) compared with calciferous KSs (COKS and CCKS). Therefore, the findings of the present study indicated a key association between specific KS components and intestinal flora, providing a theoretical basis for new treatment methods for KSs. Moreover, differences and interactions between these bacteria could initially predict specific types of urolithiasis.


Assuntos
Disbiose/genética , Microbioma Gastrointestinal/genética , Intestinos/microbiologia , Cálculos Renais/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , China/epidemiologia , Dieta , Disbiose/complicações , Disbiose/microbiologia , Disbiose/patologia , Feminino , Humanos , Intestinos/patologia , Cálculos Renais/etiologia , Cálculos Renais/microbiologia , Cálculos Renais/patologia , Masculino , Pessoa de Meia-Idade , RNA Ribossômico 16S/genética
19.
ACS Appl Mater Interfaces ; 12(17): 19581-19586, 2020 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-32255603

RESUMO

Conversion of CO2 into fuels and chemicals has been considered to be an important strategy to reduce greenhouse gas emissions and alleviate the energy crisis. Bicarbonate as a CO2 source is convenient for experimental operation. Herein, based on the synergistic effect of Ni and ZnO benefitting from the electronic transfer, ultrasmall Ni-ZnO clusters (∼2 nm) stabilized by microporous silica nanoparticles were designed and prepared for catalyzing the hydrogenation of sodium bicarbonate to formic acid. The yield of formic acid reached up to 97.0% at 260 °C/3 MPa for 2 h, which is higher than those reported non-noble metal-based catalysts. The good performance of Ni-ZnO/SiO2 can be attributed to the ultrasmall active component size and the synergy effect based on electron transfer between Ni and ZnO.

20.
ChemSusChem ; 13(18): 5015-5022, 2020 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-32662920

RESUMO

Formic acid (FA) is among the most promising hydrogen storage materials. The development of efficient catalysts for the dehydrogenation of FA via molecular-level control and precise tuning remains challenging. A series of biomimetic Ir complexes was developed for the efficient dehydrogenation of FA in an aqueous solution without base addition. A high turnover frequency of 46510 h-1 was achieved at 90 °C in 1 m FA solution with complex 1 bearing pendant pyridine. Experimental and mechanistic studies revealed that the integrated pendant pyridine and pyrazole moieties of complex 1 could act as proton relay and facilitate proton shuttling in the outer coordination sphere. This study provides a new strategy to control proton transfer accurately and a new principle for the design of efficient catalysts for FA dehydrogenation.

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