Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 80
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Angew Chem Int Ed Engl ; 61(42): e202210613, 2022 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-36064999

RESUMO

Dopant-free organic hole transport materials (HTMs) remain highly desirable for stable and efficient n-i-p perovskite solar cells (pero-SCs) but rarely succeed. Here, we propose a molecular assembly strategy to overcome the limited optoelectronic properties of organic HTMs by precisely designing a linear organic small molecule BDT-DPA-F from the atomic to the molecular levels. BDT-DPA-F can assemble into a fibril network, showing an obviously improved hole mobility and decreased energy disorder. The resultant pero-SCs showed a promising efficiency of 23.12 % (certified 22.48 %), which is the highest certified value of pero-SCs with dopant-free HTMs, to date. These devices also showed a weak-dependence of efficiency on size, enabling a state-of-the-art efficiency of 22.50 % for 1-cm2 device and 20.17 % for 15.64-cm2 module. For the first time, the pero-SCs based on dopant-free HTMs realized ultralong stabilities with T80 lifetimes over 1200 h under operation or thermal aging at 85 °C.

2.
Angew Chem Int Ed Engl ; 60(49): 25878-25883, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34585471

RESUMO

The conformational distribution and mutual interconversion of thermally activated delayed fluorescence (TADF) emitters significantly affect the exciton utilization. However, their influence on the photophysics in amorphous film states is still not known due to the lack of a suitable quantitative analysis method. Herein, we used temperature-dependent time-resolved photoluminescence spectroscopy to quantitatively measure the relative populations of the conformations of a TADF emitter for the first time. We further propose a new concept of "self-doping" for realizing high-efficiency nondoped OLEDs. Interestingly, this "compositionally" pure film actually behaves as a film with a dopant (quasi-equatorial form) in a matrix (quasi-axial form). The concentration-induced quenching that may occur at high concentrations is thus expected to be effectively relieved. The "self-doping" OLED prepared with the newly developed TADF emitter TP2P-PXZ as a neat emitting layer realizes a high maximum external quantum efficiency of 25.4 % and neglectable efficiency roll-off.

3.
J Immunol ; 196(7): 3159-67, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-26927796

RESUMO

In the process of seeking novel lung host defense regulators by analyzing genome-wide RNA sequence data from normal human airway epithelium, we detected expression of POU domain class 2-associating factor 1 (POU2AF1), a known transcription cofactor previously thought to be expressed only in lymphocytes. Lymphocyte contamination of human airway epithelial samples obtained by bronchoscopy and brushing was excluded by immunohistochemistry staining, the observation of upregulation of POU2AF1 in purified airway basal stem/progenitor cells undergoing differentiation, and analysis of differentiating single basal cell clones. Lentivirus-mediated upregulation of POU2AF1 in airway basal cells induced upregulation of host defense genes, including MX1, IFIT3, IFITM, and known POU2AF1 downstream genes HLA-DRA, ID2, ID3, IL6, and BCL6. Interestingly, expression of these genes paralleled changes of POU2AF1 expression during airway epithelium differentiation in vitro, suggesting POU2AF1 helps to maintain a host defense tone even in pathogen-free condition. Cigarette smoke, a known risk factor for airway infection, suppressed POU2AF1 expression both in vivo in humans and in vitro in human airway epithelial cultures, accompanied by deregulation of POU2AF1 downstream genes. Finally, enhancing POU2AF1 expression in human airway epithelium attenuated the suppression of host defense genes by smoking. Together, these findings suggest a novel function of POU2AF1 as a potential regulator of host defense genes in the human airway epithelium.


Assuntos
Regulação da Expressão Gênica , Imunidade/genética , Mucosa Respiratória/imunologia , Mucosa Respiratória/metabolismo , Transativadores/genética , Transativadores/metabolismo , Diferenciação Celular , Análise por Conglomerados , Células Epiteliais/metabolismo , Perfilação da Expressão Gênica , Humanos , Mucosa Respiratória/citologia , Fumar/efeitos adversos
4.
Angew Chem Int Ed Engl ; 57(30): 9480-9484, 2018 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-29863299

RESUMO

A novel molecular model of connecting electron-donating (D) and electron-withdrawing (A) moieties via a space-enough and conjugation-forbidden linkage (D-Spacer-A) is proposed to develop efficient non-doped thermally activated delayed fluorescence (TADF) emitters. 10-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl) phenoxy) phenyl)-9,9-dimethyl-9,10-dihydroacridine (DMAC-o-TRZ) was designed and synthesized accordingly. As expected, it exhibits local excited properties in single-molecule state as D-Spacer-A molecular backbone strongly suppress the intramolecular charge-transfer (CT) transition. And intermolecular CT transition acted as the vital radiation channel for neat DMAC-o-TRZ film. As in return, the non-doped device exhibits a remarkable maximum external quantum efficiency (EQE) of 14.7 %. These results prove the feasibility of D-Spacer-A molecules to develop intermolecular CT transition TADF emitters for efficient non-doped OLEDs.

5.
Nanotechnology ; 25(14): 145601, 2014 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-24622242

RESUMO

Integrating vertically aligned nanowires (NWs) on a functional substrate is important for the application of NWs in wafer scale assemblies and functional devices. However, vertically aligned NWs via the current epitaxial growth route can only be prepared on crystalline wafers. A convenient method is thus presented to overcome NW substrate limitations. Liquid metal is proposed to serve as a substrate for the initial growth of vertically aligned NWs. NWs could then be harvested from the growth substrate and integrated with functional substrates. Fabricated vertically aligned silicon NWs (SiNWs) were grown on molten Sn and then integrated into a flexible transparent poly(dimethylsiloxane) film to obtain a SiNW/functional substrate device. The device showed enhanced visible-light absorption ability and refreshable visible-light bactericidal activities with a bacterial reduction rate of close to 100%, indicating that growth with molten metal as a substrate could be a promising approach for extending the function and application of NWs.


Assuntos
Antibacterianos/química , Dimetilpolisiloxanos/química , Nanofios/química , Nanofios/microbiologia , Silício/química , Esterilização , Antibacterianos/farmacologia , Biônica , Dimetilpolisiloxanos/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/efeitos da radiação , Luz , Nanotecnologia , Nanofios/ultraestrutura , Silício/farmacologia , Estanho/química
6.
Nanotechnology ; 25(26): 265401, 2014 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-24920466

RESUMO

Photoelectrochemical (PEC) cell supports a renewable method for solving current environmental and energy issues by combining solar energy collection and photocatalysis in a single semiconductor photoelectrode. However, it is still challenged by visible light photoelectrodes. The present work reports fabricating highly efficient and stable Si nanowires (SiNWs) array as visible light photoelectrodes. It involves embedding SiNWs arrays into a transparent polymer substrate to build an axial carrier collection geometry. We demonstrated that this strategy could significantly strengthen the chemical stability of SiNWs by largely reducing their surface area. Moreover, this device structure can also enhance visible light absorption efficiency through taking advantage of the highly crystalline structure of vapor-liquid-solid (VLS) grown SiNWs. Thus it can double the photodegradation ability of SiNWs.

7.
Respirology ; 19(2): 262-268, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24286382

RESUMO

BACKGROUND AND OBJECTIVE: Recent genome-wide association studies have shown associations between variants at five loci (TNS1, GSTCD, HTR4, AGER and THSD4) and chronic obstructive pulmonary disease (COPD) or lung function. However, their association with COPD has not been proven in Chinese Han population, nor have COPD-related phenotypes been studied. The objective of this study was to look for associations between five single nucleotide polymorphisms (SNP) in these novel candidate genes and COPD susceptibility or lung function in a Chinese Han population. METHODS: Allele and genotype data on 680 COPD patients and 687 healthy controls for sentinel SNP in these five loci were investigated. Allele frequencies and genotype distributions were compared between cases and controls, and odds ratios were calculated. Potential relationships between these SNP and COPD-related lung function were assessed. RESULTS: No significant associations were found between any of the SNP and COPD in cases and controls. The SNP (rs3995090) in HTR4 was associated with COPD (adjusted P = 0.022) in never-smokers, and the SNP (rs2070600) in AGER was associated with forced expiratory volume in 1 s (FEV1 %) predicted (ß = -0.066, adjusted P = 0.016) and FEV1 /forced vital capacity (ß = -0.071, adjusted P = 0.009) in all subjects. CONCLUSIONS: The variant at HTR4 was associated with COPD in never-smokers, and the SNP in AGER was associated with pulmonary function in a Chinese Han population.


Assuntos
Povo Asiático , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Polimorfismo de Nucleotídeo Único , Doença Pulmonar Obstrutiva Crônica/genética , Espirometria/métodos , China/epidemiologia , Feminino , Frequência do Gene , Genótipo , Humanos , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Fenótipo , Doença Pulmonar Obstrutiva Crônica/etnologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia
8.
Adv Mater ; 36(25): e2400218, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38519145

RESUMO

Perovskite solar cells (pero-SCs) are highly unstable even under trace water. Although the blanket encapsulation (BE) strategy applied in the industry can effectively block moisture invasion, the commercial UV-curable adhesives (UVCAs) for BE still trigger power conversion efficiency deterioration, and the degradation mechanism remains unknown. For the first time, the functions of commercial UVCAs are revealed in BE-processed pero-SCs, where the small-sized monomer easily permeates to the perovskite surface, forming an insulating barrier to block charge extraction, while the high-polarity moiety can destroy perovskite lattice. To solve these problems, a macromer, named PIBA is carefully designed, by grafting two acrylate terminal groups on the highly gastight polyisobutylene and realizes an increased molecular diameter as well as avoided high-polarity groups. The PIBA macromer can stabilize on pero-SCs and then sufficiently crosslink, forming a compact and stable network under UV light without sacrificing device performance during the BE process. The resultant BE devices show negligible efficiency loss after storage at 85% relative humidity for 2000 h. More importantly, these devices can even reach ISO 20653:2013 Degrees of protection IPX7 standard when immersed in one-meter-deep water. This BE strategy shows good universality in enhancing the moisture stability of pero-SCs, irrespective of the perovskite composition or device structure.

9.
Guang Pu Xue Yu Guang Pu Fen Xi ; 33(11): 2978-82, 2013 Nov.
Artigo em Zh | MEDLINE | ID: mdl-24555364

RESUMO

The objectives of this study are to investigate the possible occurrence status of formamide in the intercalation system, the founction of water and the molecular configurations and orientations of formamide inserted into the interlayer of kaolinite, by washing the products with acetone to eliminate the interferences due to the outersurface absorbed formamide molecules in FTIR spectrometry. The results show that the intercalated, absorbed and free formamide probably exist in the intercalation system. Free formamide is easily to be eliminated selectively by drying, whereas the absorbed formamide is removed only by washing with the proper eluting reagent. H2O also is inserted into the interlayer during the formamide molecules' intercalation, which is deintercalated after the compounds being dried. Intercalation caused blue shifts of the inner surface OH stretching bands from 3 687 to 3 692 cm(-1), and deforming bands from 911 to 906 cm(-1), the bands at 3 651 cm(-1) disappeared with a new band appearing at 3 539 cm(-1). The frequency of the Si-O bands of kaolinite was slightly shifted. These IR bands changes implied the breaking of the H-bonds between layers of kaolinite, and the formation of new H-bonds between the kaolinite and the inserting formamide molecules in the intercalation compounds. The formamide molecules intercalated were oriented with the C-N bond perpendicular or nearly perpendicular to the (001) surface of the kaolininte and formed 2 types of H-bonding with inner-surface hydroxyls and siloxane layer of the kaolinite respectively through NH2. A novel model was provided to analyse the microstructure of kaolinite-formamide intercalation compounds. The results show that computation data is in good agreement with experimental data.

10.
Am J Med Sci ; 365(2): 169-175, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36167155

RESUMO

BACKGROUND: Th aim of this study was to analyze acute exacerbation of chronic obstructive pulmonary disease (AECOPD) readmission events and to determine whether neutrophil-to-lymphocyte ratio (NLR) and bilirubin levels were associated with readmission after discharge due to AECOPD. METHODS: A total of 170 patients with AECOPD were included. Patients were stratified into the readmission group if patients had two or more readmissions within 2 years of the previous discharge, and the non-readmission group with one readmission or none within 2 years of the last discharge. Data were collected and compared between groups. The patients were separated by the cutoffs of NLR and bilirubin level. The number of all-cause readmissions within 2 years, time to first COPD-related readmission, 1-year/2-year COPD-related readmission, 1-year/2-year all-cause mortality were compared between groups, respectively. RESULTS: Compared with the readmission group, patients of the non-readmission group had a shorter length of hospital stay, more systemic corticosteroid use, higher NLR, higher bilirubin levels, and lower eosinophils counts (p < 0.05). NLR and bilirubin levels on admission had significant association with the number of all-cause readmissions (p < 0.05). Lower bilirubin was associated with an increased risk of 1-year COPD-related readmission (OR 5.063) and 2-year COPD-related readmission (OR 4.699). CONCLUSIONS: For patients with AECOPD, longer hospital stay, and less use of systemic corticosteroids may be associated with a higher risk of readmission. NLR and bilirubin levels on admission may be related to the number of all-cause readmissions. Bilirubin can be regarded as a biomarker to predict readmission rates within 2 years after discharged throughout the course of the disease.


Assuntos
Neutrófilos , Doença Pulmonar Obstrutiva Crônica , Humanos , Progressão da Doença , Readmissão do Paciente , Estudos Retrospectivos , Linfócitos
11.
J Clin Med ; 12(3)2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36769748

RESUMO

Given the high risk of lung cancer (LC) in patients with combined pulmonary fibrosis and emphysema (CPFE), and the difficulty of early diagnosis, it is important to understand the impact of LC in these patients. The effect of LC on the development of acute exacerbation (AE) as a natural course of CPFE is still unknown. We retrospectively reviewed medical records of patients at the West China Hospital and enrolled 59 patients with CPFE combined with LC and 68 CPFE patients without LC for initial diagnosis matched in the same period. We compared the clinical characteristics and imaging features of CPFE patients with LC and without LC, and analyzed the associated factors for the prevalence of LC using binary logistic regression. Cox proportional hazards regression analysis was performed to explore risk factors of AE as a natural course of CPFE. Patients with CPFE combined with LC were more common among elderly male smokers. The most common pathological type of tumor was adenocarcinoma (24/59, 40.7%) and squamous cell carcinoma (18/59, 30.5%). Compared with those in the without LC group, the proportions of men, and ex- or current smokers, and the levels of smoking pack-years, serum CRP, IL-6, fibrinogen, complement C3 and C4 in patients with LC were significantly higher (p < 0.05). There was no significant difference in the proportion of natural-course-related AE (10.2% vs. 16.2%, p > 0.05) between the two groups. Logistic regression analysis demonstrated that pack-years ≥ 20 (OR: 3.672, 95% CI: 1.165-11.579), family history of cancer (OR: 8.353, 95% CI: 2.368-10.417), the level of fibrinogen > 4.81 g/L (OR: 3.628, 95% CI: 1.403-9.385) and serum C3 > 1.00 g/L (OR: 5.299, 95% CI: 1.727-16.263) were independently associated with LC in patients with CPFE. Compared to those without AE, CPFE patients with AE had significantly higher levels of PLR and serum CRP, with obviously lower DLCO and VC. The obviously increased PLR (HR: 3.731, 95% CI: 1.288-10.813), and decreased DLCO%pred (HR: 0.919, 95% CI: 0.863-0.979) and VC%pred (HR: 0.577, 95% CI: 0.137-0.918) rather than the presence of LC independently contributed to the development of natural-course-related AE in patients with CPFE. Pack-years, family history of cancer, the levels of fibrinogen and serum C3 were independently associated with LC in patients with CPFE. The presence of LC did not significantly increase the risk of AE as a natural course of CPFE. Clinicians should give high priority to CPFE patients, especially those with more severe fibrosis and systemic inflammation, in order to be alert for the occurrence of AE.

12.
Int J Chron Obstruct Pulmon Dis ; 18: 1219-1230, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37337582

RESUMO

Objective: This study aimed to evaluate the predictive value of neutrophil to lymphocyte ratio (NLR) for poor outcomes within 90-day in hospitalized patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Methods: A retrospective study including 503 AECOPD patients was performed, and the subjects' clinical characteristics were collected. Binary logistic regression analysis was used to identify risk factors for 90-day poor outcomes in patients with AECOPD. Receiver-operating characteristic curves (ROC) and areas under the curves (AUC) were used to assess the ability of different biomarkers to predict the risk of 90-day mortality, readmission and re-exacerbation in patients with AECOPD. Results: During the follow-up, 188 patients (38.4%) redeveloped exacerbations, 112 patients (22.9%) were readmitted, and 20 patients (4.1%) died directly resulted from COPD or COPD-related causes. Multivariate analysis demonstrated that age>72 years (OR: 14.817, 95% CI: 1.561-140.647), NLR>14.17 (OR: 9.611, 95% CI: 2.303-40.113), EOS<0.15% (OR: 8.621, 95% CI: 3.465-34.913) and BNP>2840ng/L (OR: 5.291, 95% CI: 1.367-20.474) at discharge were independent risk factors for 90-day mortality in AECOPD patients. NLR was the optimal biomarker for predicting 90-day mortality with an AUC of 0.802 (95% CI: 0.631-0.973). Using 14.17 as the critical value of NLR, the sensitivity was 76.7%, and the specificity was 88.9%. Compared with mortality, NLR had no significant advantage in predicting risk of short-term re-exacerbation (AUC=0.580, 95% CI:0.529-0.632, p=0.001) and readmission (AUC=0.555, 95% CI:0.497-0.614, p=0.045), with AUCs less than 0.6. In contrast, the predictive value of EOS (AUC=0.561, 95% CI:0.502-0.621, p=0.038) was slightly better than NLR in terms of readmission within 90 days. CRP did not serve as a well predictive biomarker for the risk of readmission and re-deterioration (p>0.05). Conclusion: NLR is of great value in predicting the risk of poor outcomes, especially COPD associated mortality, in hospitalized patients with AECOPD within 90 days after discharge.


Assuntos
Neutrófilos , Doença Pulmonar Obstrutiva Crônica , Humanos , Idoso , Prognóstico , Estudos Retrospectivos , Progressão da Doença , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/terapia , Linfócitos , Biomarcadores
13.
J Hum Genet ; 57(11): 738-46, 2012 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-22914670

RESUMO

Genome-wide association studies and integrative genomics approaches have demonstrated significant associations between chronic obstructive pulmonary disease (COPD) and single-nucleotide polymorphisms (SNPs) in the chromosome 15q25 region that includes iron-responsive element binding protein 2 gene (IREB2) and CHRNA3/5 in non-Asian populations. We investigated whether IREB2 and CHRNA3/5 polymorphisms would be associated with COPD susceptibility and COPD-related phenotypes in a Chinese Han population. Eight SNPs (rs2568494, rs2656069, rs10851906, rs1964678, rs12593229, rs965604, rs13180, rs17483929) in IREB2 gene and four SNPs (rs16969968, rs1051730, rs938682, rs8034191) in or near CHRNA3/5 locus were genotyped in a case-control study (680 COPD patients and 687 controls). No significant associations were found between any of the SNPs and COPD in either former-smokers or current-smokers. Two SNPs (rs2656069 and rs10851906) in IREB2 were associated with COPD (P=0.045 and 0.032, respectively) in non-smoker. Four SNPs (rs1964678, rs12593229, rs965604 and rs13180) in IREB2 were associated with forced expiratory volume in 1 s (FEV(1))% predicted and three SNPs (rs16969968, rs8034191 and rs1051730) in CHRNA3/5 were both associated with FEV(1)% predicted and FEV(1)/FVC in COPD cases (P range 0.007-0.050). The SNP rs8034191 near CHRNA3/5 locus was significantly associated with pack-years of smoking in COPD patients (P=0.033). We demonstrated IREB2 polymorphisms were associated with COPD in non-smoking subjects, and the effect of IREB2 gene on COPD may be independent from smoking and independent from CHRNA3/5 gene cluster. Besides, we confirmed that SNPs in these two gene loci were associated with pulmonary function and CHRNA3/5 polymorphism was associated with pack-year of smoking in COPD patients in the Chinese Han population.


Assuntos
Proteína 2 Reguladora do Ferro/genética , Proteínas do Tecido Nervoso/genética , Polimorfismo de Nucleotídeo Único , Doença Pulmonar Obstrutiva Crônica/genética , Receptores Nicotínicos/genética , Idoso , Povo Asiático/genética , Índice de Massa Corporal , Estudos de Casos e Controles , China , Feminino , Volume Expiratório Forçado/genética , Frequência do Gene , Predisposição Genética para Doença , Haplótipos , Humanos , Desequilíbrio de Ligação , Pulmão/fisiologia , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Fenótipo , Fumar/genética
14.
Chemistry ; 18(3): 975-80, 2012 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-22170498

RESUMO

Organic one-dimensional nanostructures are attractive building blocks for electronic, optoelectronic, and photonic applications. Achieving aligned organic nanowire arrays that can be patterned on a surface with well-controlled spatial arrangement is highly desirable in the fabrication of high-performance organic devices. We demonstrate a facile one-step method for large-scale controllable patterning growth of ordered single-crystal C(60) nanowires through evaporation-induced self-assembly. The patterning geometry of the nanowire arrays can be tuned by the shape of the covering hats of the confined curve-on-flat geometry. The formation of the pattern arrays is driven by a simple solvent evaporation process, which is controlled by the surface tension of the substrate (glass or Si) and geometry of the evaporation surface. By sandwiching a solvent pool between the substrate and a covering hat, the evaporation surface is confined to along the edge of the solvent pool. The geometry of the formed nanowire pattern is well defined by a surface-tension model of the evaporation channel. This simple method is further established as a general approach that is applicable to two other organic nanostructure systems. The I-V characteristics of such a parallel, organic, nanowire-array device was measured. The results demonstrate that the proposed method for direct growth of nanomaterials on a substrate is a feasible approach to device fabrication, especially to the fabrication of the parallel arrays of devices.

15.
Nanotechnology ; 23(17): 175401, 2012 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-22481573

RESUMO

In this work, we have demonstrated that a silicon nanowire (SiNW) array can be an efficient visible light photocatalyst for hydrogen generation after being modified by the 2,9,16,23-tetraaminophthalocyanine of zinc (ZnTAPc). A photoelectrochemical (PEC) cell employing a ZnTAPc modified SiNW array as photoanode was found to be able to effectively produce hydrogen at a rate of 13 µmol (cm(2) h)(-1) under 100 mw cm(-2) irradiation from a xenon lamp. It is believed that the loading of ZnTAPc can enhance the efficiency of hydrogen generation and the stability of the SiNW array. This demonstrates that the ZnTAPc modified SiNW is a promising material for solar hydrogen generation.

16.
Front Public Health ; 10: 902599, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36324472

RESUMO

Aim: This study aims to clarify the risk factors for falls to prevent severe consequences in older adults. Methods: We searched the PubMed, Web of Science, Embase, and Google Scholar databases using the terms "risk factors" OR "predicting factors" OR "predictor" AND "fall" OR "drop" to identify all relevant studies and compare their results. The study participants were divided into two groups, the "fall group" and the "control group", and differences in demographic characteristics, lifestyles, and comorbidities were compared. Results: We included 34 articles in the analysis and analyzed 22 factors. Older age, lower education level, polypharmacy, malnutrition, living alone, living in an urban area, smoking, and alcohol consumption increased the risk of falls in the aging population. Additionally, comorbidities such as cardiac disease, hypertension, diabetes, stroke, frailty, previous history of falls, depression, Parkinson's disease, and pain increased the risk of falls. Conclusion: Demographic characteristics, comorbidities, and lifestyle factors can influence the risk of falls and should be taken into consideration.


Assuntos
Acidentes por Quedas , Fragilidade , Hipertensão , Idoso , Humanos , Acidentes por Quedas/prevenção & controle , Envelhecimento , Fragilidade/epidemiologia , Fatores de Risco
17.
Chem Sci ; 13(13): 3625-3651, 2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-35432901

RESUMO

Nondoped organic light-emitting diodes (OLEDs) have drawn immense attention due to their merits of process simplicity, reduced fabrication cost, etc. To realize high-performance nondoped OLEDs, all electrogenerated excitons should be fully utilized. The thermally activated delayed fluorescence (TADF) mechanism can theoretically realize 100% internal quantum efficiency (IQE) through an effective upconversion process from nonradiative triplet excitons to radiative singlet ones. Nevertheless, exciton quenching, especially related to triplet excitons, is generally very serious in TADF-based nondoped OLEDs, significantly hindering the pace of development. Enormous efforts have been devoted to alleviating the annoying exciton quenching process, and a number of TADF materials for highly efficient nondoped devices have been reported. In this review, we mainly discuss the mechanism, exciton leaking channels, and reported molecular design strategies of TADF emitters for nondoped devices. We further classify their molecular structures depending on the functional A groups and offer an outlook on their future prospects. It is anticipated that this review can entice researchers to recognize the importance of TADF-based nondoped OLEDs and provide a possible guide for their future development.

18.
Adv Mater ; 34(14): e2110482, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35122342

RESUMO

The built-in electric field (BEF) intensity of silicon heterojunction solar cells can be easily enhanced by selective doping to obtain high power conversion efficiencies (PCEs), while it is challenging for perovskite solar cells (pero-SCs) because of the difficulty in doping perovskites in a controllable way. Herein, an effective method is reported to enhance the BEF of FA0.92 MA0.08 PbI3 perovskite by doping an organic ferroelectric material, poly(vinylidene fluoride):dabcoHReO4 (PVDF:DH) with high polarizability, that can be driven even by the BEF of the device itself. The polarization of PVDF:DH produces an additional electric field, which is maintained permanently, in a direction consistent with that of the BEF of the pero-SC. The BEF superposition can more sufficiently drive the charge-carrier transport and extraction, thus suppressing the nonradiative recombination occurring in the pero-SCs. Moreover, the PVDF:DH dopant benefits the formation of a mesoporous PbI2 film, via a typical two-step processing method, thereby promoting perovskite growth with high crystallinity and a few defects. The resulting pero-SC shows a promising PCE of 24.23% for a 0.062 cm2 device (certified PCE of 23.45%), and a remarkable PCE of 22.69% for a 1 cm2 device, along with significantly improved moisture resistances and operational stabilities.

19.
Langmuir ; 27(13): 7996-9, 2011 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-21651296

RESUMO

Geometry-based adhesion arising from hierarchical surface structure enables microspheres to adhere to cells strongly, which is essential for inorganic microcapsules that function as drug delivery or diagnostic imaging agents. However, constructing a hierarchical structure on the outer shell of the products via the current microcapsule synthesis method is difficult. This work presents a novel approach to fabricating hollow microspheres with a hierarchical shell structure through the vapor-liquid-solid (VLS) process in which liquid indium droplets act as both templates for the formation of silica capsules and catalysts for the growth of hierarchical shell structure. This hierarchical shell structure offers the hollow microsphere an enhanced geometry-based adhesion. The results provide a facile method for fabricating hollow spheres and enriching their function through tailoring the geometry of their outer shells.


Assuntos
Índio/química , Microesferas , Dióxido de Silício/síntese química , Adsorção , Estrutura Molecular , Tamanho da Partícula , Porosidade , Dióxido de Silício/química , Propriedades de Superfície , Volatilização
20.
Nanotechnology ; 22(28): 285606, 2011 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-21654033

RESUMO

Under high humidity and appropriate temperature, tris (8-hydroxyquinoline) aluminum (Alq3) solid micro/nanostructures may be etched into hollow structures and still retain their crystalline structures and surface morphologies. The shapes and sizes of the hollow structures are easily adjusted by varying the experimental parameters. Throughout the entire process, water is introduced into the system instead of organic or corrosive solvents, making this method convenient and environmentally friendly; it can also be extended to application in other materials such as TCNQ.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA