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1.
J Intellect Disabil Res ; 68(6): 598-609, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38481070

RESUMO

BACKGROUND: Altered gait patterns and reduced walking speed are commonly reported in adults with Down syndrome (DS). Research on the effects of DS-specific exercise programmes on adults with DS is lacking. The purpose of this quasi-experimental study was to evaluate the changes in gait deviations and walking speed in adults with DS after a DS-specific exercise programme. METHODS: Twenty participants underwent a 12-week, DS-specific exercise programme in a telehealth format. Before and after the intervention, gait deviations were assessed with the Ranchos Los Amigos Observational Gait Analysis form, and comfortable walking speed was evaluated with the 4-m walk test. RESULTS: We observed increased comfortable walking speed and reduced gait deviations in the whole gait cycle in adults with DS after the intervention. There were fewer gait deviations during single-leg stance and swing-limb advancement and at the hip, knee and ankle joints after the 12-week exercise programme. CONCLUSIONS: Gait speed and observable gait impairments in adults with DS significantly improved following a 12-week telehealth exercise programme.


Assuntos
Síndrome de Down , Terapia por Exercício , Velocidade de Caminhada , Humanos , Síndrome de Down/fisiopatologia , Síndrome de Down/reabilitação , Síndrome de Down/complicações , Masculino , Feminino , Adulto , Velocidade de Caminhada/fisiologia , Terapia por Exercício/métodos , Adulto Jovem , Telemedicina/métodos , Transtornos Neurológicos da Marcha/reabilitação , Transtornos Neurológicos da Marcha/fisiopatologia , Transtornos Neurológicos da Marcha/etiologia , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde
2.
Psychooncology ; 31(6): 960-969, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35072308

RESUMO

OBJECTIVES: This study provided information about sleep disruption, particularly its prevalence and severity among Hong Kong Chinese childhood cancer survivors. Additionally, we identified the factors influencing sleep disruption and explored how fatigue, depressive symptoms and physical activity (PA) affect sleep disruption. METHODS: Four hundred two survivors 6-18 years old and 50 age- and gender-matched healthy counterparts were assessed for depressive symptoms, fatigue, PA and subjective sleep quality. Demographic and clinical information were collected. Multiple logistic regression analyses were conducted to identify any factors contributing to poor sleep. RESULTS: Mean scores of depressive symptoms, fatigue for children and that for adolescents, and PA in survivors were 16.1 (SD = 11.1), 24.6 (SD = 10.3), 27.7 (SD = 7.8), and 3.08 (SD = 2.9), respectively. 44.8% of the survivors were poor sleepers, which was more that in healthy counterparts. The three most common sleep problem were prolonged sleep latency (31.9%), daytime dysfunction (23.4%), and sleep disturbance (22.9%). The time since last treatment (children: AOR = 0.54, 95% CI = 0.30-0.96, p = 0.04; adolescents: AOR = 0.80, 95% CI = 0.70-0.92, p < 0.01) and PA levels (children: AOR = 0.46, 95% CI = 0.260-0.82, p = 0.01; adolescents: AOR = 0.70, 95% CI = 0.49-0.98, p = 0.04) were negatively associated with sleep disruption, while depressive symptoms (children: AOR = 1.31, 95% CI = 1.04-1.64, p = 0.02; adolescents: AOR = 1.07, 95% CI = 1.01-1.13, p = 0.03), fatigue (children: AOR = 1.15, 95% CI = 1.00-1.31, p = 0.04; adolescents: AOR = 1.08, 95% CI = 1.02-1.15, p = 0.01), number of treatment received (children: AOR = 16.56, 95% CI = 1.27-216.82, p = 0.03; adolescents: AOR = 7.30, 95% CI = 2.36-22.56, p < 0.01), and co-sleeping (children: AOR = 29.19, 95% CI = 1.65-511.57, p = 0.02; adolescents: AOR = 4.63, 95% CI = 1.22-17.61, p = 0.02) were positively associated with sleep disruption. CONCLUSION: Physical activity made the largest contribution to reduce sleep disruption. It is crucial to advocate for the adoption and maintenance of PA in survivorship.


Assuntos
Sobreviventes de Câncer , Neoplasias , Adolescente , Criança , Estudos Transversais , Fadiga/diagnóstico , Fadiga/epidemiologia , Hong Kong/epidemiologia , Humanos , Neoplasias/epidemiologia , Neoplasias/terapia , Sono , Sobreviventes
3.
Phys Chem Chem Phys ; 24(36): 22057-22066, 2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-36070485

RESUMO

The structural and vibrational properties of pristine graphite and point defects in graphite are studied by tight-binding (TB) calculations using a three-center TB potential model. We showed that the three-center TB potential without "ad hoc" van der Waals interaction corrections can accurately describe the inter-layer distance of graphite and the lowest-energy structures and stabilities of typical point defects in graphite. The results from our TB calculations are in good agreement with those from density-functional theory calculations with van der Waals interaction corrections. We also investigated the vibrational properties to gain better understanding on the localization of vibrational states induced by the point defects. Our calculation results show that although localized or quasi-localized vibrational modes can be found in all defected graphite, the localization induced by Frenkel pair, dual-vacancy, and dual-interstitial defects is much stronger. Atomic displacements associated with the localized vibrational modes induced by these three point defects are also analyzed.

4.
Acta Pharmacol Sin ; 43(11): 2993-3001, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35478244

RESUMO

Vestibular schwannoma (VS), one of characteristic tumors of neurofibromatosis type 2 (NF2), is an intracranial tumor that arises from Schwann cells of the vestibular nerve. VS results in hearing loss, tinnitus, dizziness, and even death, but there are currently no FDA-approved drugs for treatment. In this study, we established a high-throughput screening to discover effective compounds that could inhibit the viability of VS cells. Among 1019 natural products from the Korea Chemical Bank screened, we found that celastrol, a pentacyclic triterpene derived from a Tripterygium Wilfordi plant, exerted potent inhibitory effect on the viability of VS cells with an IC50 value of 0.5 µM. Celastrol (0.5, 1 µM) dose-dependently inhibited the proliferation of primary VS cells derived from VS patients. Celastrol also inhibited the growth, and induced apoptosis of two other VS cell lines (HEI-193 and SC4). Aberrant activation of Wnt/ß-catenin signaling has been found in VS isolated from clinically defined NF2 patients. In HEI-193 and SC4 cells, we demonstrated that celastrol (0.1, 0.5 µM) dose-dependently inhibited TOPFlash reporter activity and protein expression of ß-catenin, but not mRNA level of ß-catenin. Furthermore, celastrol accelerated the degradation of ß-catenin by promoting the formation of the ß-catenin destruction complex. In nude mice bearing VS cell line SC4 allografts, administration of celastrol (1.25 mg · kg-1 · d-1, i.p. once every 3 days for 2 weeks) significantly suppressed the tumor growth without showing toxicity. Collectively, this study demonstrates that celastrol can inhibit Wnt/ß-catenin signaling by promoting the degradation of ß-catenin, consequently inhibiting the growth of VS.


Assuntos
Neuroma Acústico , beta Catenina , Camundongos , Animais , beta Catenina/metabolismo , Neuroma Acústico/tratamento farmacológico , Neuroma Acústico/metabolismo , Neuroma Acústico/patologia , Camundongos Nus , Proliferação de Células , Linhagem Celular Tumoral , Triterpenos Pentacíclicos/farmacologia , Apoptose , Via de Sinalização Wnt
5.
Hong Kong Med J ; 28(3): 204-214, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35697524

RESUMO

INTRODUCTION: Compared with young children who have acute lymphoblastic leukaemia (ALL), adolescents with ALL have unfavourable disease profiles and worse survival. However, limited data are available regarding the characteristics and outcomes of adolescents with ALL who underwent treatment in clinical trials. The aim of this study was to investigate the causes of treatment failure in adolescents with ALL. METHODS: We retrospectively analysed the outcomes of 711 children with ALL, aged 1-18 years, who were enrolled in five clinical trials of paediatric ALL treatment between 1993 and 2015. RESULTS: Among the 711 children with ALL, 530 were young children (1-9 years at diagnosis) and 181 were adolescents (including 136 younger adolescents [10-14 years] and 45 older adolescents [15-18 years]). Compared with young children who had ALL, adolescents with ALL were less likely to have favourable genetic features and more likely to demonstrate poor early response to treatment. The 10-year overall survival and event-free survival rates were significantly lower among adolescents than among young children (77.9% vs 87.6%, P=0.0003; 69.7% vs 76.5%, P=0.0117). There were no significant differences in the 10-year cumulative incidence of relapse, but the 10-year cumulative incidence of treatment-related death (TRD) was significantly greater among adolescents (7.2%) than among young children (2.3%; P=0.002). Multivariable analysis showed that both younger and older adolescents (vs young children) had worse survival and greater incidence of TRD. CONCLUSION: Adolescents with ALL had worse survival because they experienced a greater incidence of TRD. There is a need to investigate optimal treatment adjustments and novel targeted agents to achieve better survival rates (without excessive toxicity) among adolescents with ALL.


Assuntos
Recidiva Local de Neoplasia , Leucemia-Linfoma Linfoblástico de Células Precursoras , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica , Criança , Pré-Escolar , Intervalo Livre de Doença , Humanos , Incidência , Recidiva Local de Neoplasia/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Estudos Retrospectivos , Taxa de Sobrevida
6.
Int J Mol Sci ; 23(9)2022 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-35563597

RESUMO

Cystic fibrosis transmembrane conductance regulator (CFTR) is highly expressed on the ocular epithelium and plays a pivotal role in the fluid secretion driven by chloride transport. Dry eye disease is one of the most common diseases with limited therapeutic options. In this study, a high-throughput screening was performed to identify novel CFTR activators capable of inducing chloride secretion on the ocular surface. The screening of 50,000 small molecules revealed three novel CFTR activators. Among them, the most potent CFTR activator, Cact-3 (7-(3,4-dimethoxyphenyl)-N-(4-ethoxyphenyl)pyrazolo [1,5-α]pyrimidine-2-carboxamide), produced large and sustained Cl- currents in WT-CFTR-expressing FRT cells with no alterations of ANO1 and hERG channel activity. The application of Cact-3 strongly activated CFTR in the ocular epithelia of mice and it also significantly increased CFTR-mediated Cl- transport in a primary cultured human conjunctival epithelium. Cact-3 strongly stimulated tear secretion in normal mice. In addition, Cact-3 significantly reduced ocular surface damage and the expression of proinflammatory factors, including interleukin (IL)-1ß, IL-6, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ in an experimental mouse model of dry eye disease. These results suggest that Cact-3, a novel CFTR activator, may be a potential development candidate for the treatment of dry eye disease.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística , Síndromes do Olho Seco , Cloretos/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Síndromes do Olho Seco/tratamento farmacológico , Humanos , Transporte de Íons , Escopolamina
7.
Georgian Med News ; (333): 6-12, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36780614

RESUMO

Following increased cultural awareness, expanded access to care, and decreased stigmatization, the number of transgender individuals seeking gender affirmation surgery such as gender-affirmation mastectomy (GAM) continues to rise. While post-mastectomy breast tissue is often sent for pathologic evaluation, few studies address the utility and standardization of this practice. This literature review evaluates the pathology findings in GAM specimens reported in the medical literature. A systematic review following PRISMA guidelines was performed to evaluate all medical publications related to pathology reports following GAM. The overall type and incidence of benign and malignant breast lesions were analyzed to elucidate which patient characteristics significantly affect the pathology findings. Overall, eight of 488 identified studies met inclusion criteria (1278 patients). The incidence of pre-malignant lesions was 2.42%, including flat epithelial atypia (0.08%), atypical hyperplasia (0.23%), atypical ductal hyperplasia (1.33%), atypical lobular hyperplasia (0.39%), and lobular carcinoma in situ (0.39%).Patient age, hormonal therapy, and family / patient history of breast cancer were inconsistently reported among included studies. Lack of standardized pathologic classification did not permit further statistical analysis. Although patients who undergo GAM are unlikely to have premalignant or malignant findings on breast pathology examination, pathologic evaluation of breast tissue remains common practice. Additional studies, which include a standardized method of pathologic evaluation, are necessary before practice guidelines can be recommended.


Assuntos
Neoplasias da Mama , Carcinoma in Situ , Carcinoma Intraductal não Infiltrante , Lesões Pré-Cancerosas , Humanos , Feminino , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/cirurgia , Neoplasias da Mama/patologia , Mastectomia , Hiperplasia , Carcinoma Intraductal não Infiltrante/epidemiologia , Carcinoma Intraductal não Infiltrante/patologia , Carcinoma Intraductal não Infiltrante/cirurgia , Carcinoma in Situ/epidemiologia , Carcinoma in Situ/patologia , Carcinoma in Situ/cirurgia , Lesões Pré-Cancerosas/patologia
8.
Health Qual Life Outcomes ; 19(1): 176, 2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34229705

RESUMO

BACKGROUND: Sleep disruption is a prevalent symptom reported by survivors of childhood cancer. However, there is no validated instrument for assessing this symptom in this population group. To bridge the literature gap, this study translated and adapted the Pittsburgh Sleep Quality Index (PSQI) for Hong Kong Chinese cancer survivors and examined its psychometric properties and factor structure. METHODS: A convenience sample of 402 Hong Kong Chinese childhood cancer survivors aged 6-18 years were asked to complete the Chinese version of the PSQI, Center for Epidemiologic Studies Depression Scale for Children (CES-DC), Fatigue Scale-Child (FS-C)/Fatigue Scale-Adolescent (FS-A), and Pediatric Quality of Life Inventory (PedsQL). To assess known-group validity, 50 pediatric cancer patients and 50 healthy counterparts were recruited. A sample of 40 children were invited to respond by phone to the PSQI 2 weeks later to assess test-retest reliability. A cutoff score for the translated PSQI used with the survivors was determined using receiver operating characteristic analysis. RESULTS: The Chinese version of the PSQI had a Cronbach alpha of 0.71, with an intraclass correlation coefficient of 0.90. Childhood cancer survivors showed significantly lower mean PSQI scores than children with cancer, and significantly higher mean scores than healthy counterparts. This reflected that childhood cancer survivors had a better sleep quality than children with cancer, but a poorer sleep quality than healthy counterparts. We observed positive correlations between PSQI and CES-DC scores and between PSQI and FS-A/FS-C scores, but a negative correlation between PSQI and PedsQL scores. The results supported that the Chinese version of the PSQI showed convergent validity. Confirmatory factor analysis showed that the translated PSQI data best fit a three-factor model. The best cutoff score to detect insomnia was 5, with a sensitivity of 0.81 and specificity of 0.70. CONCLUSION: The Chinese version of the PSQI is a reliable and valid instrument to assess subjective sleep quality among Hong Kong Chinese childhood cancer survivors. The validated PSQI could be used in clinical settings to provide early assessments for sleep disruption. Appropriate interventions can therefore be provided to minimize its associated long-term healthcare cost. Trial registration This study was registered in ClinicalTrials.gov with the reference number NCT03858218.


Assuntos
Sobreviventes de Câncer , Psicometria , Sono , Inquéritos e Questionários , Adolescente , Povo Asiático , Sobreviventes de Câncer/psicologia , Criança , Análise Fatorial , Fadiga/diagnóstico , Feminino , Hong Kong , Humanos , Masculino , Qualidade de Vida , Curva ROC , Reprodutibilidade dos Testes , Distúrbios do Início e da Manutenção do Sono/diagnóstico , Traduções
9.
Phys Chem Chem Phys ; 23(8): 4835-4840, 2021 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-33605963

RESUMO

Amorphous diamond structures are generated by quenching high-density high-temperature liquid carbon using tight-binding molecular-dynamics simulations. We show that the generated amorphous diamond structures are predominated by strong tetrahedral bonds with the sp3 bonding fraction as high as 97%, thus exhibit an ultra-high incompressibility and a wide band gap close to those of crystalline diamond. A small amount of sp2 bonding defects in the amorphous sample contributes to localized electronic states in the band gap while large local strain gives rise to localization of vibrational modes at both high and low frequency regimes.

10.
J Thromb Thrombolysis ; 52(3): 925-933, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33959860

RESUMO

Omeprazole is commonly co-prescribed with clopidogrel. Clopidogrel requires bio-activation by cytochrome P450 CYP2C19. Omeprazole may reduce clopidogrel's antithrombotic efficacy by inhibiting CYP2C19. Studies in Caucasians receiving omeprazole with clopidogrel showed no significant increase in death and myocardial infarction with this drug-drug interaction. There are limited large-scale studies in Asians, who may have a greater prevalence of CYP2C19 loss-of-function polymorphisms. A single centre retrospective cohort study was undertaken based on a review of medication records and prescription data. Patients prescribed clopidogrel from 2009 to 2012 were followed-up with until December 2012 (median:29 months). The primary outcome was all-cause mortality and secondary outcomes were myocardial infarction (MI), cerebrovascular accidents, and subsequent coronary interventions. Of 12,440 patients prescribed clopidogrel, 62%(n = 7714) were on omeprazole (63.8% Chinese, 13.9% Malay, 12.4% Indian, 10.0% others), and 38%(n = 4726) were not on omeprazole or other proton pump inhibitors (62.6% Chinese, 13.5% Malay, 10.7% Indian, 13.2% others). Mortality after co-prescription occurred in 14.3%(n = 1101) of patients, compared to 6.3%(n = 300) of patients prescribed clopidogrel only. Multivariate analysis using propensity score adjusted analysis showed no significant increase in all-cause mortality with co-prescription (adjusted hazards ratio [AHR] 1.13, [95%CI 0.95-1.35]). Patients on co-prescription had a higher risk of subsequent MI (16% vs 3.8%; AHR 2.03 [95%CI 1.70-2.44]), but not of cerebrovascular accidents (5.0% vs 2.0%; AHR 0.98 [95%CI 0.76-1.27]) or coronary interventions (1.7% vs 0.7%; AHR 1.28 [95%CI 0.83-1.96]). The risk of a subsequent MI was higher in the Malay (AHR 2.43 [95%CI 1.68-3.52]) and Chinese (AHR 2.06 [95%CI 1.63-2.60]) population as compared to the Indian (AHR 1.56 [95%CI 1.06-2.31]) population. In conclusion, the use of clopidogrel with omeprazole is associated with an increased risk of MI, but not mortality or stroke, in this multi-ethnic Asian population. These risks appear to vary among different ethnic groups.


Assuntos
Infarto do Miocárdio , Acidente Vascular Cerebral , Povo Asiático , Clopidogrel/uso terapêutico , Citocromo P-450 CYP2C19 , Interações Medicamentosas , Etnicidade , Humanos , Infarto do Miocárdio/tratamento farmacológico , Omeprazol/uso terapêutico , Inibidores da Agregação Plaquetária/uso terapêutico , Inibidores da Bomba de Prótons/uso terapêutico , Estudos Retrospectivos , Acidente Vascular Cerebral/tratamento farmacológico , Ticlopidina/uso terapêutico
11.
J Chem Phys ; 155(19): 194503, 2021 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-34800941

RESUMO

Al-rich Al-Ce alloys have the possibility of replacing heavier steel and cast irons for use in high-temperature applications. Knowledge about the structures and properties of Al-Ce alloys at the liquid state is vital for optimizing the manufacture process to produce desired alloys. However, reliable molecular dynamics simulation of Al-Ce alloy systems remains a great challenge due to the lack of accurate Al-Ce interatomic potential. Here, an artificial neural network (ANN) deep machine learning (ML) method is used to develop a reliable interatomic potential for Al-Ce alloys. Ab initio molecular dynamics simulation data on the Al-Ce liquid with a small unit cell (∼200 atoms) and on the known Al-Ce crystalline compounds are collected to train the interatomic potential using ANN-ML. The obtained ANN-ML model reproduces well the energies, forces, and atomic structure of the Al90Ce10 liquid and crystalline phases of Al-Ce compounds in comparison with the ab initio results. The developed ANN-ML potential is applied in molecular dynamics simulations to study the structures and properties of the metallic Al90Ce10 liquid, which would provide useful insight into the guiding experimental process to produce desired Al-Ce alloys.

12.
Res Nurs Health ; 44(3): 438-448, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33754400

RESUMO

There is growing concern about mental health problems among juveniles. Evidence shows that adventure-based training can reduce depressive symptoms in school children. However, a rigorous empirical investigation of the effectiveness of such training in enhancing resilience among juveniles has not yet been performed. In this study, a randomized controlled trial was conducted to examine the effectiveness of adventure-based training in enhancing resilience and self-esteem and reducing depressive symptoms among juveniles. Secondary school students from grades 7 to 9 (aged 12-16 years) who attended the Integrated Children and Youth Services Centre in a large public housing estate in Hong Kong from December 20, 2018 to November 25, 2019 were invited to participate in this study. We randomly assigned 228 eligible adolescents to an experimental group (n = 115) that received a 2-day/1-night adventure-based training or a placebo control group (n = 113) that received 2 days of leisure activities organized by the Integrated Children and Youth Services Centre. Data were collected at baseline and 3 and 6 months after the corresponding interventions. The primary outcome was resilience at 6 months. The secondary outcomes were depressive symptoms and self-esteem at 6 months. Compared with the placebo control group, the experimental group showed significantly higher resilience (p = 0.001) and fewer depressive symptoms (p = 0.02) at 6 months, and significantly higher self-esteem at 3 months (p = 0.04), but not at 6 months (p = 0.12). However, the generalizability of the findings is limited as we used a convenience sample.


Assuntos
Depressão/prevenção & controle , Jogos Recreativos , Resiliência Psicológica , Estudantes/psicologia , Adolescente , Criança , Feminino , Hong Kong , Humanos , Masculino , Autoimagem
13.
Int J Mol Sci ; 22(8)2021 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-33921231

RESUMO

Dry eye disease is one of the most common diseases, with increasing prevalence in many countries, but treatment options are limited. Cystic fibrosis transmembrane conductance regulator (CFTR) is a major ion channel that facilitates fluid secretion in ocular surface epithelium and is a potential target of therapeutic agent for the treatment of dry eye disease. In this study, we performed a cell-based, high-throughput screening for the identification of novel natural products that activate CFTR and restore the aqueous deficiency in dry eye. Screening of 1000 natural products revealed isorhamnetin, a flavonol aglycone, as a novel CFTR activator. Electrophysiological studies showed that isorhamnetin significantly increased CFTR chloride current, both wild type and ∆F508-CFTR. Isorhamnetin did not alter intracellular cAMP levels and the activity of other ion channels, including ANO1, ENaC, and hERG. Notably, application of isorhamnetin on mouse ocular surface induced CFTR activation and increased tear volume. In addition, isorhamnetin significantly reduced ocular surface damage and expression of interleukin (IL)-1ß, IL-8, and tumor necrosis factor (TNF)-α in an experimental mouse model of dry eye. These data suggest that isorhamnetin may be used to treat dry eye disease.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/genética , Síndromes do Olho Seco/tratamento farmacológico , Quercetina/análogos & derivados , Animais , Modelos Animais de Doenças , Síndromes do Olho Seco/genética , Síndromes do Olho Seco/patologia , Células Epiteliais/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Interleucina-1beta/genética , Interleucina-8/genética , Camundongos , Quercetina/farmacologia , Fator de Necrose Tumoral alfa/genética
14.
J Environ Manage ; 277: 111434, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33045646

RESUMO

This study assessed the environmental impacts of the formulation of graphene oxide (GO)/multi-walled carbon nanotubes (MWCNTs) conductive membranes and of the process operating parameters of electrically-enhanced palm oil mill effluent (POME) filtration. Two different analyses approaches were employed, cradle-to-gate approach for conductive membrane production and gate-to-gate approach for the POME filtration process. The parameters in conductive-membrane formulation (e.g. the weight ratio of carbon nanomaterials, and concentration of GO/MWCNT nanohybrids) and process operating parameters (e.g. electric field strength and electricity operating mode) were investigated. The findings herein are twofold. Firstly, for the fabrication of GO/MWCNT conductive membranes, the best weight ratio of GO:MWCNTs was found to be 1:9, given its superior membrane electrical conductivity with lower environmental impacts by 8.51% compared to pristine MWCNTs. The most suitable concentration of carbon nanomaterials was found to be 5 wt%, given its lowest impacts on resource depletion, human health, and ecosystems. Secondly, for the electrically-enhanced POME filtration, the optimum process operating parameters were found to be the application of an electric field of 300 V/cm in the continuous mode, given its lower environmental impacts (22.99%-89.30%) secondary to its requirement of the least electricity to produce permeate. The present study has established not only the optimized conditions in membrane formulation but also the operating parameters of electrically-enhanced filtration; such findings enable the use of cleaner production and sustainable approach to minimize fouling for industrial applications, whilst maintaining excellent efficiency.


Assuntos
Resíduos Industriais , Nanotubos de Carbono , Ecossistema , Condutividade Elétrica , Eletricidade , Resíduos Industriais/análise , Óleo de Palmeira , Óleos de Plantas
15.
Phys Rev Lett ; 124(15): 157401, 2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32357060

RESUMO

We discover hidden Rashba fine structure in CH_{3}NH_{3}PbI_{3} and demonstrate its quantum control by vibrational coherence through symmetry-selective vibronic (electron-phonon) coupling. Above a critical threshold of a single-cycle terahertz pump field, a Raman phonon mode distinctly modulates the middle excitonic states with persistent coherence for more than ten times longer than the ones on two sides that predominately couple to infrared phonons. These vibronic quantum beats, together with first-principles modeling of phonon periodically modulated Rashba parameters, identify a threefold excitonic fine structure splitting, i.e., optically forbidden, degenerate dark states in between two bright ones with a narrow, ∼3 nm splitting. Harnessing of vibronic quantum coherence and symmetry inspires light-perovskite quantum control and sub-THz-cycle "Rashba engineering" of spin-split bands for ultimate multifunction device.

16.
Phys Chem Chem Phys ; 22(26): 14630-14636, 2020 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-32568353

RESUMO

We have performed systematic molecular dynamics simulations to study the structures of liquid carbon at 5000 K with the weight density ranging from 1.4 to 3.5 g cm-3, using a three-center tight-binding potential of carbon. The simulation results show that the bonding characteristics of the liquid changes predominately from twofold to threefold, and then to fourfold coordination as the density increases. Signals of two structural changes at the densities of about 1.9 and 3.0 g cm-3 respectively are revealed by the slope changes in the density dependence of structural, electronic and dynamical properties. Our simulation results suggest that there are three distinct liquid carbon phases in this density range. However, further thermodynamics calculations, e.g., free energy calculations, would be required to clarify the possible liquid-liquid transitions.

17.
Phys Chem Chem Phys ; 22(33): 18467-18479, 2020 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-32778859

RESUMO

An interatomic potential for the Al-Tb alloy around the composition of Al90Tb10 is developed using the deep neural network (DNN) learning method. The atomic configurations and the corresponding total potential energies and forces on each atom obtained from ab initio molecular dynamics (AIMD) simulations are collected to train a DNN model to construct the interatomic potential for the Al-Tb alloy. We show that the obtained DNN model can well reproduce the energies and forces calculated by AIMD simulations. Molecular dynamics (MD) simulations using the DNN interatomic potential also accurately describe the structural properties of the Al90Tb10 liquid, such as partial pair correlation functions (PPCFs) and bond angle distributions, in comparison with the results from AIMD simulations. Furthermore, the developed DNN interatomic potential predicts the formation energies of the crystalline phases of the Al-Tb system with an accuracy comparable to ab initio calculations. The structure factors of the Al90Tb10 metallic liquid and glass obtained by MD simulations using the developed DNN interatomic potential are also in good agreement with the experimental X-ray diffraction data. The development of short-range order (SRO) in the Al90Tb10 liquid and the undercooled liquid is also analyzed and three dominant SROs, i.e., Al-centered distorted icosahedron (DISICO) and Tb-centered '3661' and '15551' clusters, respectively, are identified.

18.
Atmos Environ (1994) ; 222: 1-117026, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32461735

RESUMO

While fine particulate matters are decreasing in the Pearl River Delta (PRD) region, the regional ozone (O3) shows an increasing trend that affects human health, leading to an urgent need for scientific understanding of source-receptor relationship between O3 and its precursor emissions given the changing background composition. We advanced and applied an adjoint air quality model to map contributions of individual O3 precursor emission sources [nitrogen oxides (NOx) and volatile organic compound (VOC)] at each location to annual regional O3 concentrations and to identify the possible dominant influential pathways of emission sources to O3 at different spatiotemporal scales. Additionally, we introduced the novel adjoint sensitivity approach to assess the relationship between precursor emissions and O3-induced premature mortality. Adjoint results show that Shenzhen was a major source contributor to regional O3 throughout all seasons, of which 49.4% (3.8%) were from its NOx (VOC) emissions. Local emissions (within PRD) contributed to 83% of the regional O3 whereas only ~54% of the estimated ~4000 regional O3-induced premature mortalities. The discrepancy between these two contributions was because O3-induced mortalities are dependent on not only O3 concentration, but incident rate and population density. We also found that a city with low O3-induced mortalities could have significant emission contributions to health impact in the region since the transport pathways could be through transport of local O3 or through transport of O3 precursors that form regional O3 thereafter. It is therefore necessary to formulate emission control policies from both air quality and public health perspectives, and it is also critical to have better understanding of influential pathways of emission sources to O3.

19.
Nano Lett ; 19(9): 6058-6064, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31398046

RESUMO

van der Waals (vdW) heterostructures, which are produced by the precise assemblies of varieties of two-dimensional (2D) materials, have demonstrated many novel properties and functionalities. Here we report a nanoplasmonic study of vdW heterostructures that were produced by depositing ordered molecular layers of pentacene on top of graphene. We find through nanoinfrared (IR) imaging that surface plasmons formed due to the collective oscillations of Dirac Fermions in graphene are highly sensitive to the adjacent pentacene layers. In particular, the plasmon wavelength declines systematically but nonlinearly with increasing pentacene thickness. Further analysis and density functional theory (DFT) calculations indicate that the observed peculiar thickness dependence is mainly due to the tunneling-type electron transfer from pentacene to graphene. Our work unveils a new method for tailoring graphene plasmons and deepens our understanding of the intriguing nano-optical phenomena due to interlayer couplings in novel vdW heterostructures.

20.
Curr Opin Neurol ; 32(6): 886-894, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31592789

RESUMO

PURPOSE OF REVIEW: Primary central nervous system lymphoma (PCNSL) is a rare but aggressive variant of non-Hodgkin lymphoma. The diagnostic gold standard remains the pathologic review of tumor tissue mainly collected though biopsies. The majority of PCNSL are diffuse large B cell lymphoma (DLBCL). Biopsies are invasive procedures, and there have been efforts to develop minimally invasive diagnostic testing using serum and cerebral spinal fluid. This article reviews multiple markers that could potentially serve as future diagnostic tools and predictors of treatment response. RECENT FINDINGS: Many studies have attempted to classify DLBCL into different subtypes for prognostic purposes using methods such as immunohistochemistry. PCNSL often falls under the activated B-cell-like subgroup, and further genomic sequencing has identified alterations in genes within the B-cell receptor signaling axis at increased frequencies. Two such genes, MYD88 and CD79B, implicate the involvement of the NF-kB (nuclear factor kappa-light-chain enhancer of activated B cells) pathway, and targeted agents to this pathway are currently being used in the treatment of relapsed/refractory PCNSL. SUMMARY: Although recent genomic profiling of PCNSL has increased the understanding of drivers in this disease and has also led to the introduction of targeted inhibitors, these markers have not yet been used for diagnostic and/or prognostic purposes. Further studies will need to evaluate if they hold great diagnostic potential.


Assuntos
Biomarcadores Tumorais , Neoplasias do Sistema Nervoso Central/diagnóstico , Perfilação da Expressão Gênica/normas , Linfoma não Hodgkin/diagnóstico , Neoplasias do Sistema Nervoso Central/genética , Humanos , Linfoma não Hodgkin/genética
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