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1.
Antimicrob Agents Chemother ; 68(4): e0095623, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38446062

RESUMO

Viral RNA-dependent RNA polymerase (RdRp), a highly conserved molecule in RNA viruses, has recently emerged as a promising drug target for broad-acting inhibitors. Through a Vero E6-based anti-cytopathic effect assay, we found that BPR3P0128, which incorporates a quinoline core similar to hydroxychloroquine, outperformed the adenosine analog remdesivir in inhibiting RdRp activity (EC50 = 0.66 µM and 3 µM, respectively). BPR3P0128 demonstrated broad-spectrum activity against various severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern. When introduced after viral adsorption, BPR3P0128 significantly decreased SARS-CoV-2 replication; however, it did not affect the early entry stage, as evidenced by a time-of-drug-addition assay. This suggests that BPR3P0128's primary action takes place during viral replication. We also found that BPR3P0128 effectively reduced the expression of proinflammatory cytokines in human lung epithelial Calu-3 cells infected with SARS-CoV-2. Molecular docking analysis showed that BPR3P0128 targets the RdRp channel, inhibiting substrate entry, which implies it operates differently-but complementary-with remdesivir. Utilizing an optimized cell-based minigenome RdRp reporter assay, we confirmed that BPR3P0128 exhibited potent inhibitory activity. However, an enzyme-based RdRp assay employing purified recombinant nsp12/nsp7/nsp8 failed to corroborate this inhibitory activity. This suggests that BPR3P0128 may inhibit activity by targeting host-related RdRp-associated factors. Moreover, we discovered that a combination of BPR3P0128 and remdesivir had a synergistic effect-a result likely due to both drugs interacting with separate domains of the RdRp. This novel synergy between the two drugs reinforces the potential clinical value of the BPR3P0128-remdesivir combination in combating various SARS-CoV-2 variants of concern.


Assuntos
Monofosfato de Adenosina/análogos & derivados , Alanina/análogos & derivados , COVID-19 , Pirazóis , Quinolinas , Humanos , SARS-CoV-2/metabolismo , RNA Polimerase Dependente de RNA/metabolismo , Simulação de Acoplamento Molecular , Tratamento Farmacológico da COVID-19 , Antivirais/química
2.
Mol Carcinog ; 62(3): 348-359, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36453714

RESUMO

Adenosine-to-inosine (A-to-I) RNA editing is the most common posttranscriptional editing to create somatic mutations and increase proteomic diversity. However, the functions of the edited mutations are largely underexplored. To identify novel targets in lung adenocarcinoma (LUAD), we conducted a genome-wide somatic A-to-I RNA editing analysis of 23 paired adjacent normal and LUAD transcriptomes and identified 26,280 events, including known nonsynonymous AZIN1-S367G and novel RHOAiso2 (RHOA isoform 2)-R176G, tubulin gamma complex associated protein 2 (TUBGCP2)-N211S, and RBMXL1-I40 M mutations. We validated the edited mutations in silico in multiple databases and in newly collected LUAD tissue pairs with the SEQUENOM MassARRAY® and TaqMan PCR Systems. We selected RHOAiso2-R176G due to its significant level, isoform-specificity, and being the most common somatic edited nonsynonymous mutation of RHOAiso2 to investigate its roles in LUAD tumorigenesis. RHOAiso2 is a ubiquitous but low-expression alternative spliced isoform received a unique Alu-rich exon at the 3' RHOA mRNA to become an editing RNA target, leading to somatic hypermutation and protein diversity. Interestingly, LUAD patients harboring the RHOAiso2-R176G mutation were associated with aberrant RHOA functions, cancer cell proliferation and migration, and poor clinical outcomes in transcriptome analysis. Mechanistically, RHOAiso2-R176G mutation-expressing LUAD cells potentiate RHOA-guanosine triphosphate (GTP) activity to phosphorylate ROCK1/2 effectors and enhance cell proliferation and migration in vitro and increase tumor growth in xenograft and systemic metastasis models in vivo. Taken together, the RHOAiso2-R176G mutation is a common somatic A-to-I edited mutation of the hypermutated RHOA isoform 2. It is an oncogenic and isoform-specific theranostic target that activates RHOA-GTP/p-ROCK1/2 signaling to promote tumor progression.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Humanos , RNA , Proteômica , Adenosina , Adenocarcinoma de Pulmão/genética , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Neoplasias Pulmonares/genética , Guanosina Trifosfato , Inosina , Mutação , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Linhagem Celular Tumoral , Proteína rhoA de Ligação ao GTP/genética , Proteína rhoA de Ligação ao GTP/metabolismo
3.
Cell ; 135(6): 1065-73, 2008 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-19070577

RESUMO

Hybrids between species are usually unviable or sterile. One possible mechanism causing reproductive isolation is incompatibility between genes from different species. These "speciation" genes are interacting components that cannot function properly when mixed with alleles from other species. To test whether such genes exist in two closely related yeast species, we constructed hybrid lines in which one or two chromosomes were derived from Saccharomyces bayanus, and the rest were from Saccharomyces cerevisiae. We found that the hybrid line with Chromosome 13 substitution was completely sterile and identified Aep2, a mitochondrial protein encoded on Chromosome 13, to cause the sporulation defect as S. bayanus AEP2 is incompatible with S. cerevisiae mitochondria. This is caused by the inability of S. bayanus Aep2 protein to regulate the translation of the S. cerevisiae OLI1 mRNA. We speculate that AEP2 and OLI1 have evolved during the adaptation of S. bayanus to nonfermentable carbon sources, thereby driving speciation.


Assuntos
Saccharomyces cerevisiae/genética , Saccharomyces/genética , Carbono/metabolismo , Quimera , Proteínas Fúngicas/genética , Especiação Genética , Genoma Fúngico , Genoma Mitocondrial , Mitocôndrias/metabolismo , ATPases Mitocondriais Próton-Translocadoras/genética , Biossíntese de Proteínas , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética
4.
J Med Internet Res ; 23(10): e25777, 2021 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-34668872

RESUMO

BACKGROUND: Integrated community case management (CCM) has led to reductions in child mortality in Malawi resulting from illnesses such as malaria, pneumonia, and diarrhea. However, adherence to CCM guidelines is often poor, potentially leading to inappropriate clinical decisions and poor outcomes. We determined the impact of an e-CCM app on the referral, reconsultation, and hospitalization rates of children presenting to village clinics in Malawi. OBJECTIVE: We determined the impact of an electronic version of a smartphone-based CCM (e-CCM) app on the referral, reconsultation, and hospitalization rates of children presenting to village clinics in Malawi. METHODS: We used a stepped-wedge, cluster-randomized trial to compare paper-based CCM (control) with and without the use of an e-CCM app on smartphones from November 2016 to February 2017. A total of 102 village clinics from 2 districts in northern Malawi were assigned to 1 of 6 clusters, which were randomized on the sequencing of the crossover from the control phase to the intervention phase as well as the duration of exposure in each phase. Children aged ≥2 months to <5 years who presented with acute illness were enrolled consecutively by health surveillance assistants. The primary outcome of urgent referrals to higher-level facilities was evaluated by using multilevel mixed effects models. A logistic regression model with the random effects of the cluster and the fixed effects for each step was fitted. The adjustment for potential confounders included baseline factors, such as patient age, sex, and the geographical location of the village clinics. Calendar time was adjusted for in the analysis. RESULTS: A total of 6965 children were recruited-49.11% (3421/6965) in the control phase and 50.88% (3544/6965) in the intervention phase. After adjusting for calendar time, children in the intervention phase were more likely to be urgently referred to a higher-level health facility than children in the control phase (odds ratio [OR] 2.02, 95% CI 1.27-3.23; P=.003). Overall, children in the intervention arm had lower odds of attending a repeat health surveillance assistant consultation (OR 0.45, 95% CI 0.34-0.59; P<.001) or being admitted to a hospital (OR 0.75, 95% CI 0.62-0.90; P=.002), but after adjusting for time, these differences were not significant (P=.07 for consultation; P=.30 for hospital admission). CONCLUSIONS: The addition of e-CCM decision support by using smartphones led to a greater proportion of children being referred to higher-level facilities, with no apparent increase in hospital admissions or repeat consultations in village clinics. Our findings provide support for the implementation of e-CCM tools in Malawi and other low- and middle-income countries with a need for ongoing assessments of effectiveness and integration with national digital health strategies. TRIAL REGISTRATION: ClinicalTrials.gov NCT02763345; https://clinicaltrials.gov/ct2/show/NCT02763345.


Assuntos
Administração de Caso , Smartphone , Criança , Hospitalização , Humanos , Malaui , Encaminhamento e Consulta
5.
J Cell Sci ; 131(16)2018 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-30054385

RESUMO

Alteration of protein localization is an important strategy for cells to regulate protein homeostasis upon environmental stresses. In the budding yeast Saccharomyces cerevisiae, many proteins relocalize and form cytosolic granules during chronological aging. However, the functions and exact components of these protein granules remain uncharacterized in most cases. In this study, we performed a genome-wide analysis of protein localization in stationary phase cells, leading to the discovery of 307 granule-forming proteins and the identification of new components in the Hsp42-stationary phase granule (Hsp42-SPG), P-bodies, Ret2 granules and actin bodies. We further characterized the Hsp42-SPG, which contains the largest number of protein components, including many molecular chaperones, metabolic enzymes and regulatory proteins. Formation of the Hsp42-SPG efficiently downregulates the activities of sequestered components, which can be differentially released from the granule based on environmental cues. We found a similar structure in the pre-whole genome duplication yeast species, Lachancea kluyveri, suggesting that the Hsp42-SPG is a common machinery allowing chronologically aged cells to contend with changing environments when available energy is limited. This article has an associated First Person interview with the first author of the paper.


Assuntos
Senescência Celular/fisiologia , Grânulos Citoplasmáticos/metabolismo , Proteínas de Choque Térmico/metabolismo , Dobramento de Proteína , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/fisiologia , Resposta a Proteínas não Dobradas/fisiologia , Metabolismo Energético/fisiologia , Proteínas de Choque Térmico/genética , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Organismos Geneticamente Modificados , Ligação Proteica , Transporte Proteico/genética , Proteostase/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética
6.
EMBO Rep ; 18(1): 87-101, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27920033

RESUMO

Mitochondrial-nuclear incompatibility has a major role in reproductive isolation between species. However, the underlying mechanism and driving force of mitochondrial-nuclear incompatibility remain elusive. Here, we report a pentatricopeptide repeat-containing (PPR) protein, Ccm1, and its interacting partner, 15S rRNA, to be involved in hybrid incompatibility between two yeast species, Saccharomyces cerevisiae and Saccharomyces bayanus S. bayanus-Ccm1 has reduced binding affinity for S. cerevisiae-15S rRNA, leading to respiratory defects in hybrid cells. This incompatibility can be rescued by single mutations on several individual PPR motifs, demonstrating the highly evolvable nature of PPR proteins. When we examined other PPR proteins in the closely related Saccharomyces sensu stricto yeasts, about two-thirds of them showed detectable incompatibility. Our results suggest that fast co-evolution between flexible PPR proteins and their mitochondrial RNA substrates may be a common driving force in the development of mitochondrial-nuclear hybrid incompatibility.


Assuntos
Núcleo Celular/metabolismo , Proteínas Fúngicas/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Sequência de Aminoácidos , Núcleo Celular/genética , Cromossomos Fúngicos , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Genoma Fúngico , Mitocôndrias/genética , Proteínas Mitocondriais/química , Proteínas Mitocondriais/genética , Modelos Moleculares , Mutação , Peptídeos , Ligação Proteica , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , RNA , RNA Mitocondrial , RNA Ribossômico , Sequências Repetitivas de Ácido Nucleico
7.
BMC Med Educ ; 18(1): 61, 2018 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-29609596

RESUMO

BACKGROUND: Despite the increasing uptake of information and communication technologies (ICT) within healthcare services across developing countries, community healthcare workers (CHWs) have limited knowledge to fully utilise computerised clinical systems and mobile apps. The 'Introduction to Information and Communication Technology and eHealth' course was developed with the aim to provide CHWs in Malawi, Africa, with basic knowledge and computer skills to use digital solutions in healthcare delivery. The course was delivered using a traditional and a blended learning approach. METHODS: Two questionnaires were developed and tested for face validity and reliability in a pilot course with 20 CHWs. Those were designed to measure CHWs' knowledge of and attitudes towards the use of ICT, before and after each course, as well as their satisfaction with each learning approach. Following validation, a randomised controlled trial was conducted to assess the effectiveness of the two learning approaches. A total of 40 CHWs were recruited, stratified by position, gender and computer experience, and allocated to the traditional or blended learning group using block randomisation. Participants completed the baseline and follow-up questionnaires before and after each course to assess the impact of each learning approach on their knowledge, attitudes, and satisfaction. Per-item, pre-post and between-group, mean differences for each approach were calculated using paired and unpaired t-tests, respectively. Per-item, between-group, satisfaction scores were compared using unpaired t-tests. RESULTS: Scores across all scales improved after attending the traditional and blended learning courses. Self-rated ICT knowledge was significantly improved in both groups with significant differences between groups in seven domains. However, actual ICT knowledge scores were similar across groups. There were no significant differences between groups in attitudinal gains. Satisfaction with the course was generally high in both groups. However, participants in the blended learning group found it more difficult to follow the content of the course. CONCLUSIONS: This study shows that there is no difference between blended and traditional learning in the acquisition of actual ICT knowledge among community healthcare workers in developing countries. Given the human resource constraints in remote resource-poor areas, the blended learning approach may present an advantageous alternative to traditional learning.


Assuntos
Agentes Comunitários de Saúde/educação , Tecnologia da Informação , Informática Médica/educação , Inquéritos e Questionários , Adulto , Atitude Frente aos Computadores , Telefone Celular , Computadores de Mão , Feminino , Humanos , Malaui , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Telemedicina
8.
Phys Chem Chem Phys ; 18(22): 15251-9, 2016 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-27210896

RESUMO

The electrical properties and field-emission characteristics of ZnO nanowires (ZnO-NWs) fabricated using a vapor-liquid-solid method were systematically investigated. In particular, we explored the effects of Al-doped ZnO (AZO) films (thickness 4-100 nm) deposited on ZnO-NWs using an atomic layer deposition (ALD) method on the optoelectronic properties. The results show that the sheet resistance of net-like ZnO-NW structures can be significantly improved, specifically to become ∼1/1000 of the sheet resistance of the as-grown ZnO-NWs, attaining less than 10 Ω Sq(-1). The emission current density measured at the maximum field was roughly quadrupled relative to that of the as-grown ZnO-NWs. The data of the enhanced field-emission characteristics show that, with the ALD system, the AZO films of small resistance are readily coated on a structure with a high aspect ratio and the coating radius is controlled relative to the turn-on voltage and current density. The ultrathin AZO film from a one-monolayer coating process also significantly improved emission properties through modification of the effective work function at the AZO/ZnO-NW surface.

9.
Int J Geriatr Psychiatry ; 29(12): 1212-20, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24854229

RESUMO

OBJECTIVE: There have been dramatic societal changes in East Asia over the last hundred years. Several of the established risk factors could have important period and cohort effects. This study explores temporal variation of dementia prevalence in mainland China, Hong Kong and Taiwan taking study methods into account. METHODS: Seventy prevalence studies of dementia in mainland China, Hong Kong and Taiwan were identified from 1980 to 2012. Five period groups (before 1990, 1990 ~ 1994, 1995 ~ 1999, 2000 ~ 2004 and 2005 ~ 2012) and five birth cohort groups (1895 ~ 1909, 1910 ~ 1919, 1920 ~ 1929, 1930 ~ 1939 and 1940 ~ 1950) were categorised using the year of investigation and 5-year age groups. Pooled prevalence by age, period and birth cohort groups was estimated through meta-regression model and meta-analysis taking diagnostic criteria and age structure into account. RESULTS: After adjusting for diagnostic criteria, the study age range and age structure, the prevalence of dementia in the older population aged 60 years and over fluctuated across periods but not reaching significance and were estimated as 1.8%, 2.5%, 2.1%, 2.4% and 3.1% for the five periods from pre-1990 to 2005 ~ 2012. A potential increasing pattern from less to more recent birth cohort groups was found in the major studies using older diagnostic criteria with wider differences in the age groups over 70 years. CONCLUSIONS: This study found no significant variation across periods but suggested a potential cohort effect. The influence of societal changes might moderate early life experiences across different generations with substantial impact on mental health in older age.


Assuntos
Demência/epidemiologia , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , China/epidemiologia , Estudos de Coortes , Hong Kong/epidemiologia , Humanos , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Taiwan/epidemiologia
10.
Am J Pathol ; 180(3): 1159-1169, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22222226

RESUMO

The role of aldehyde dehydrogenase 1 (ALDH1) as an ovarian cancer stem cell marker and its clinical significance have rarely been explored. We used an Aldefluor assay to isolate ALDH1-bright (ALDH1(br)) cells from epithelial ovarian cancer cell lines and characterized the properties of the stem cells. ALDH1(br) cells were enriched in ES-2 (1.3%), TOV-21G (1.0%), and CP70 (1.2%) cells. Both ALDH1(br) and ALDH1(low) cells repopulated stem cell heterogeneity, formed spheroids, and grew into tumors in immunocompromised mice, although these processes were more efficient in ALDH1(br) cells. In the ES-2 and CP70 cells, ALDH1(br) cells conferred more chemoresistance, and were more enriched in CD44 (by 1.74-fold and 5.18-fold, respectively) than in CD133 (by 1.39-fold and 1.17-fold, respectively), compared with ALDH1(low) cells. Immunohistochemical staining for ALDH1 on a tissue microarray containing 84 epithelial ovarian cancer samples revealed that patients with higher ALDH1 expression (>50%) had poor overall survival, compared with those with lower ALDH1 (P = 0.004) and yielded an odds ratio of death of 2.43 (95% CI = 1.12 to 5.28) by multivariate analysis. The results did not support ALDH1 alone as an ovarian cancer stem cell marker, but demonstrated that ALDH1 is associated with CD44 expression, chemoresistance, and poor clinical outcome. The use of a combination of ALDH1 with other stem cell markers may help define ovarian cancer stem cells more stringently.


Assuntos
Biomarcadores Tumorais/metabolismo , Receptores de Hialuronatos/metabolismo , Isoenzimas/metabolismo , Neoplasias Epiteliais e Glandulares/enzimologia , Neoplasias Ovarianas/metabolismo , Retinal Desidrogenase/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Família Aldeído Desidrogenase 1 , Animais , Carcinoma Epitelial do Ovário , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Estimativa de Kaplan-Meier , Camundongos , Camundongos SCID , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/enzimologia , Recidiva Local de Neoplasia/mortalidade , Neoplasias Epiteliais e Glandulares/tratamento farmacológico , Neoplasias Epiteliais e Glandulares/mortalidade , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/enzimologia , Neoplasias Ovarianas/mortalidade , Esferoides Celulares , Ensaios Antitumorais Modelo de Xenoenxerto , Adulto Jovem
11.
PLoS Biol ; 8(7): e1000432, 2010 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-20652018

RESUMO

Nuclear-mitochondrial conflict (cytonuclear incompatibility) is a specific form of Dobzhansky-Muller incompatibility previously shown to cause reproductive isolation in two yeast species. Here, we identified two new incompatible genes, MRS1 and AIM22, through a systematic study of F2 hybrid sterility caused by cytonuclear incompatibility in three closely related Saccharomyces species (S. cerevisiae, S. paradoxus, and S. bayanus). Mrs1 is a nuclear gene product required for splicing specific introns in the mitochondrial COX1, and Aim22 is a ligase encoded in the nucleus that is required for mitochondrial protein lipoylation. By comparing different species, our result suggests that the functional changes in MRS1 are a result of coevolution with changes in the COX1 introns. Further molecular analyses demonstrate that three nonsynonymous mutations are responsible for the functional differences of Mrs1 between these species. Functional complementation assays to determine when these incompatible genes altered their functions show a strong correlation between the sequence-based phylogeny and the evolution of cytonuclear incompatibility. Our results suggest that nuclear-mitochondrial incompatibility may represent a general mechanism of reproductive isolation during yeast evolution.


Assuntos
Saccharomyces/genética , Aerobiose/genética , Núcleo Celular/genética , Núcleo Celular/metabolismo , Cruzamentos Genéticos , Evolução Molecular , Regulação Fúngica da Expressão Gênica , Genes Fúngicos/genética , Genoma Mitocondrial/genética , Haploidia , Íntrons/genética , Mitocôndrias/genética , Mutação/genética , Filogenia , Reprodução , Especificidade da Espécie
12.
Nanotechnology ; 24(11): 115601, 2013 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-23448895

RESUMO

The oxidation state and size of Pt nanoparticles attached to alkali metal titanate nanotubes (MTNTs=M2Ti3O7, M = Li(+), Na(+), K(+), Cs(+)) via ion exchange (indicated by the added label '-IE') and wet impregnation (indicated by the added label '-IMP') methods varied systematically with the cation of the MTNTs. X-ray photoelectron spectroscopy revealed that the binding energy of Pt was reduced to a low value when the support was changed from LiTNTs to CsTNTs, yielding a Pt(δ-) oxidation state. Thus, a space charge layer (SCL) was constructed at the interface between the Pt particle and MTNT support; the former carried the negative charge, and the alkali cation and proton in the hydroxyl group of the latter carried the positive charge. Due to a higher M/Ti atomic ratio in MTNTs, a higher electron density accumulated on Pt particles in Pt/MTNTs-IMP than on those in Pt/MTNTs-IE. Sub-ambient temperature temperature-programmed reduction and transmission electron microscopy revealed that because of the difference in reducibility of PtOx/MTNTs, the mean Pt particle size followed the order Pt/CsTNTs > Pt/KTNTs > Pt/NaTNTs > Pt/LiTNTs and Pt/MTNTs-IMP > Pt/MTNTs-IE. DRIFTS (diffuse reflectance infrared Fourier transform spectroscopy) showed that owing to its interaction with SCL, cinnamaldehyde adsorbed on Pt mainly through the C=C bond at the Pt-MTNT interfaces, and the small Pt particles in Pt/LiTNTs adsorbed three times more cinnamaldehyde than those in Pt/CsTNTs. Due to the competition between the adsorption of cinnamaldehyde and C=C activation, Pt/KTNT-IMP is the most active Pt/MTNT catalysts, achieving a conversion of 100% in the hydrogenation of cinnamaldehyde at 2 atm and 313 K. The carbonyl stretching of adsorbed cinnamaldehyde was almost unperturbed by adsorption (at 1705 cm(-1)), suggesting that Pt(δ-) and the π electrons in the carbonyl group repel each other, so the CH=O group points upward and away from the Pt surface, preventing it from being hydrogenated and causing Pt/MTNTs to exhibit high 3-phenyl propionaldehyde selectivities of 75-80%.

13.
Phys Chem Chem Phys ; 15(26): 10761-6, 2013 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-23689603

RESUMO

Metallic gold (Au) and platinum (Pt) thin films were deposited on silicon nanocones (Si-NCs) by sputtering to elucidate the effects of work function and conductivities on the field electron emission characteristics of surface-modified Si-NCs. The results showed that for Pt/Si-NCs and Au/Si-NCs, although the turn-on field defined at a corresponding current density of 10 µA cm(-2) only improved from 4.20 V µm(-1) for bare Si-NCs to 3.65 and 2.90 V µm(-1), respectively, the emission current density measured at 5.00 V µm(-1) was enhanced by orders of magnitude, reaching 1.82 mA cm(-2) for Au/Si-NCs. Compared to those obtained from various surface-modified Si-nanostructures, such as ZnO/Si-nanopillars and ferroelectrics/Si-nanotips, the current results represent an interesting alternative route for producing surface-modified Si-NCs that might be useful for optical and electronic applications.


Assuntos
Nanoestruturas/química , Silício/química , Ouro/química , Platina/química , Semicondutores , Propriedades de Superfície , Temperatura , Óxido de Zinco/química
14.
J Formos Med Assoc ; 112(11): 699-706, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24183199

RESUMO

BACKGROUND/PURPOSE: EQ-5D (EuroQol-5 dimensions) is a preference-based measure of health, which is widely used in cost-utility analyses. It has been suggested that each country should develop its own value set. We therefore sought to develop the quality weights of the EQ-5D health states with the time trade-off (TTO) method in Taiwan. METHODS: A total of 745 respondents consisting of employees and volunteers in 17 different hospitals were recruited and interviewed. Each of them valued 13 of 73 EQ-5D health states using the TTO method. Based on the three exclusion criteria for valuation data, only 456 (61.21%) respondents were considered eligible for data analysis. The quality weights for all EQ-5D health states were modeled by generalized estimating equations (GEEs). RESULTS: Over half of the responses were given negative values, and the medical personnel seemed to have a significantly higher TTO value (+0.1) than others after controlling for other predictors. The N3 model (level 3 occurred within at least 1 dimension) yielded an acceptable fit for the observed OTT data [mean absolute error (MAE) = 0.056, R(2) = 0.35]. The magnitude of mean absolute differences (MADs) between Taiwan data and those from the UK, Japan, and South Korea ranged from 0.146 to 0.592, but the rank correlation coefficients were all above 0.811. CONCLUSION: This study reaffirms the differences in health-related preference values across countries. The high proportion of negative values might indicate that we have also partially measured the intensity of fear in addition to the utility of different health states.


Assuntos
Nível de Saúde , Vigilância da População/métodos , Qualidade de Vida , Anos de Vida Ajustados por Qualidade de Vida , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Inquéritos e Questionários , Taiwan , Fatores de Tempo
15.
J Manipulative Physiol Ther ; 36(6): 364-8, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23830708

RESUMO

OBJECTIVE: The objective of this cross-sectional observational study was to determine whether asymmetric hip mobility was associated with neck pain in young adults. METHODS: Three hundred twenty-seven freshmen students were recruited from an urban university and underwent the Patrick's flexion, abduction, external rotation, extension (FABERE) test for comparison of the functional mobility of bilateral hip joints during the health examination. A logistic regression model was constructed to determine whether the asymmetry measured by the Patrick's FABERE test was associated with neck pain after adjusting for factors of sex and exercise habits. RESULTS: The frequency of asymmetric results of the Patrick's FABERE test among the students who reported neck pain was significantly higher than that of those without neck pain (54.2% vs 26.5%; P < .001). After adjusting for the above confounders, the odds ratio of asymmetric results of a Patrick's FABERE test was 2.99 (95% confidence interval, 1.57-5.72; P < .001). CONCLUSIONS: Imbalanced mobility of the hip joints might be associated with an increased incidence of neck pain.


Assuntos
Articulação do Quadril/fisiopatologia , Cervicalgia/etiologia , Amplitude de Movimento Articular , Adolescente , Estudos Transversais , Feminino , Humanos , Masculino , Movimento , Cervicalgia/epidemiologia , Rotação
16.
PLoS One ; 18(5): e0284367, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37141243

RESUMO

MAIN OBJECTIVE: A cohort of adult Malawian people living with HIV (PLHIV) testing positive for cryptococcal antigenemia was observed and followed to determine the outcomes and risk factors for attrition. METHODS CONCEPT: Eligible PLHIV were enrolled at 5 health facilities in Malawi, representing different levels of health care. ART naïve patients, ART defaulters returning to care, and patients with suspected or confirmed ART treatment failure with CD4 <200 cells/µL or clinical stage 3 or 4 were enrolled and received CrAg tests on whole blood specimens from August 2018 to August 2019. Hospitalized PLHIV were enrolled and tested for CrAg from January 2019 to August 2019, regardless of CD4 or clinical stage. Patients with cryptococcal antigenemia were managed per Malawian clinical guidelines and were followed up for six months. Survival and risk factors for attrition at six months were assessed. RESULTS: A total of 2146 patients were screened and 112 (5.2%) had cryptococcal antigenemia. Prevalence ranged from 3.8% (Mzuzu Central Hospital) to 25.8% (Jenda Rural Hospital). Of the 112 patients with antigenemia, 33 (29.5%) were diagnosed with concurrent CM at the time of enrollment. Six-month crude survival of all patients with antigenemia (regardless of CM status) ranged from 52.3% (assuming lost-to-follow-up (LTFU) patients died) to 64.9% (if LTFU survived). Patients who were diagnosed with concurrent CM by CSF test had poor survival (27.3-39.4%). Patients with antigenemia who were not diagnosed with concurrent CM had 71.4% (if LTFU died)- 89.8% (if LTFU survived) survival at six months. In adjusted analyses, patients with cryptococcal antigenemia detected after admission to inpatient care (aHR: 2.56, 1.07-6.15) and patients with concurrent CM at the time of positive antigenemia result (aHR: 2.48, 1.04-5.92) had significantly higher hazard of attrition at six months. CONCLUSIONS: Overall, our findings indicate a need for routine access to CrAg screening and pre-emptive fluconazole treatment as a way to detect cryptococcal antigenemia and prevent CM in outpatient and inpatient settings. Rapid access to diagnosis and treatment for cryptococcal meningitis (CM) with gold-standard antifungals is needed to improve survival of patients with advanced HIV in Malawi.


Assuntos
Cryptococcus , Infecções por HIV , Meningite Criptocócica , Adulto , Humanos , Malaui/epidemiologia , Antígenos de Fungos , Meningite Criptocócica/diagnóstico , Meningite Criptocócica/epidemiologia , Fatores de Risco , Contagem de Linfócito CD4 , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Infecções por HIV/tratamento farmacológico
17.
J Chem Phys ; 137(2): 024509, 2012 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-22803549

RESUMO

The high pressure induced phase transition in rhenium diselenides (ReSe(2)) and gold-doped rhenium diselenides (Au-ReSe(2)) at ambient temperature have been investigated using angular-dispersive x-ray diffraction (ADXRD) under high pressure up to around 10.50 and 9.98 GPa, respectively. In situ ADXRD measurements found that the phase transition pressures of ReSe(2) and Au-ReSe(2) began at 9.98 and 8.52 GPa, respectively. Compressibilities analysis shows the relationship of along c-axis > along a-axis > along b-axis. The linear compressibility of the pressure dependence of α, ß, and γ of ReSe(2) shows that a phase transition can be related to a counterclockwise rotational trend of the selenium atoms around the chain of Re(4) atoms during the decrease of the c-axis distance by a combination of stresses due to the bending effect of α and stretching effect of ß. The cause of the reduction of the phase transition pressure of Au-ReSe(2) is attributed mainly to a structural distortion as evidenced by the observation of a weak clockwise rotational trend of Se atoms around the chain of Re(4) atoms in the pressure range 3.99-4.99 GPa which subsequently reversed to counterclockwise rotation under higher pressure.

18.
Sensors (Basel) ; 12(12): 17620-32, 2012 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-23250281

RESUMO

The practice of meditation has become an interesting research issue in recent decades. Meditation is known to be beneficial for health improvement and illness reduction and many studies on meditation have been made, from both the physiological and psychological points of view. It is a fundamental requirement of meditation practice to be able to sit without body motion. In this study, a novel body motion monitoring and estimation system has been developed. A wireless tri-axis accelerometer is used to measure body motion. Both a mean and maximum motion index is derived from the square summation of three axes. Two experiments were conducted in this study. The first experiment was to investigate the motion index baseline among three leg-crossing postures. The second experiment was to observe posture dynamics for thirty minute's meditation. Twenty-six subjects participated in the experiments. In one experiment, thirteen subjects were recruited from an experienced meditation group (meditation experience > 3 years); and the other thirteen subjects were beginners (meditation experience < 1 years). There was a significant posture stability difference between both groups in terms of either mean or maximum parameters (p < 0.05), according to the results of the experiment. Results from another experiment showed that the motion index is different for various postures, such as full-lotus < half-lotus < non-lotus.


Assuntos
Meditação , Postura/fisiologia , Tecnologia sem Fio , Adulto , Feminino , Corpo Humano , Humanos , Perna (Membro)/fisiologia , Masculino
19.
Nat Commun ; 13(1): 4394, 2022 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-35906261

RESUMO

Dobzhansky-Muller incompatibilities represent a major driver of reproductive isolation between species. They are caused when interacting components encoded by alleles from different species cannot function properly when mixed. At incipient stages of speciation, complex incompatibilities involving multiple genetic loci with weak effects are frequently observed, but the underlying mechanisms remain elusive. Here we show perturbed proteostasis leading to compromised mitosis and meiosis in Saccharomyces cerevisiae hybrid lines carrying one or two chromosomes from Saccharomyces bayanus var. uvarum. Levels of proteotoxicity are correlated with the number of protein complexes on replaced chromosomes. Proteomic approaches reveal that multi-protein complexes with subunits encoded by replaced chromosomes tend to be unstable. Furthermore, hybrid defects can be alleviated or aggravated, respectively, by up- or down-regulating the ubiquitin-proteasomal degradation machinery, suggesting that destabilized complex subunits overburden the proteostasis machinery and compromise hybrid fitness. Our findings reveal the general role of impaired protein complex assembly in complex incompatibilities.


Assuntos
Saccharomyces cerevisiae , Saccharomyces , Especiação Genética , Hibridização Genética , Proteômica , Saccharomyces/genética , Saccharomyces cerevisiae/genética
20.
Phys Chem Chem Phys ; 13(11): 5099-104, 2011 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-21298153

RESUMO

Through monitoring the evolution of the X-ray diffraction peaks, the phase transformation of PVP-protected Ag and Au nanoparticle deposits (NPDs) on electronic substrates of Cu and Ni upon heating in air was investigated via in situ synchrotron radiation X-ray diffraction. With an increasing temperature, the broad diffraction peak of nano-sized Ag and Au particles with the original average diameters of 4.2 nm and 9.6 nm, respectively, became sharp because of particle coarsening and coalescence. Complex phase transitions among Au, Cu, AuCu(3) and CuO(x) were observed, mainly due to the negative enthalpy of mixing between Au and Cu. The interactions between NPDs and the substrates affected the shift of diffraction peaks to lower angles, caused by thermal expansion and also the temperature for the oxide formation. Compared to Au, Ag NPDs did not form intermetallic compounds with Cu and the formation of copper oxides can also be retarded mainly due to the phase separation feature of the Ag-Cu system.

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