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1.
Nature ; 630(8017): 619-624, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38898294

RESUMO

The basal plane of graphene can function as a selective barrier that is permeable to protons1,2 but impermeable to all ions3,4 and gases5,6, stimulating its use in applications such as membranes1,2,7,8, catalysis9,10 and isotope separation11,12. Protons can chemically adsorb on graphene and hydrogenate it13,14, inducing a conductor-insulator transition that has been explored intensively in graphene electronic devices13-17. However, both processes face energy barriers1,12,18 and various strategies have been proposed to accelerate proton transport, for example by introducing vacancies4,7,8, incorporating catalytic metals1,19 or chemically functionalizing the lattice18,20. But these techniques can compromise other properties, such as ion selectivity21,22 or mechanical stability23. Here we show that independent control of the electric field, E, at around 1 V nm-1, and charge-carrier density, n, at around 1 × 1014 cm-2, in double-gated graphene allows the decoupling of proton transport from lattice hydrogenation and can thereby accelerate proton transport such that it approaches the limiting electrolyte current for our devices. Proton transport and hydrogenation can be driven selectively with precision and robustness, enabling proton-based logic and memory graphene devices that have on-off ratios spanning orders of magnitude. Our results show that field effects can accelerate and decouple electrochemical processes in double-gated 2D crystals and demonstrate the possibility of mapping such processes as a function of E and n, which is a new technique for the study of 2D electrode-electrolyte interfaces.


Assuntos
Grafite , Prótons , Grafite/química , Hidrogenação , Catálise
2.
Br J Haematol ; 204(3): 1005-1016, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38083818

RESUMO

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare condition caused by severe ADAMTS13 deficiency, leading to platelet aggregation and thrombosis. Despite treatment, patients are prone to cognitive impairment and depression. We investigated brain changes in iTTP patients during remission using advanced magnetic resonance imaging (MRI) techniques, correlating these changes with mood and neurocognitive tests. Twenty iTTP patients in remission (30 days post-haematological remission) were compared with six healthy controls. MRI scans, including standard and specialized sequences, were conducted to assess white matter health. Increased T1 relaxation times were found in the cingulate cortex (p < 0.05), and elevated T2 relaxation times were observed in the cingulate cortex, frontal, parietal and temporal lobes (p < 0.05). Pathological changes in these areas are correlated with impaired cognitive and depressive scores in concentration, short-term memory and verbal memory. This study highlights persistent white matter damage in iTTP patients, potentially contributing to depression and cognitive impairment. Key regions affected include the frontal lobe and cingulate cortex. These findings have significant implications for the acute and long-term management of iTTP, suggesting a need for re-evaluation of treatment approaches during both active phases and remission. Further research is warranted to enhance our understanding of these complexities.


Assuntos
Disfunção Cognitiva , Púrpura Trombocitopênica Trombótica , Substância Branca , Humanos , Púrpura Trombocitopênica Trombótica/terapia , Proteína ADAMTS13
3.
Phys Chem Chem Phys ; 26(20): 14930-14936, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38738788

RESUMO

The unique 4f orbitals and abundant electronic energy levels of rare earth elements enable effective doping and modification to enhance hydrogen storage performance, making it an increasingly prominent focus of research. The structures of neutral and cationic CeHn0/+ (n = 2-20) clusters have been determined using the Crystal Structure AnaLYsis by Particle Swarm Optimization (CALYPSO) method in conjunction with density functional theory (DFT). Interestingly, the CeH13 and CeH14+ exhibit remarkable stability in the doublet state with Cs and C2v symmetry, respectively. The adsorption energy of CeHn0/+ (n = 2-20) suggests a preference for H atoms to chemically adsorb on Ce atoms. The analysis of molecular orbital composition reveals that the stability of both CeH13 and CeH14+ is attributed to the significant hybridization between the H 1s and Ce 4f orbitals. Both CeH13 and CeH14+ demonstrate significant hydrogen storage capacities, with values reaching 8.5 wt% and 9.1 wt%, respectively.

4.
Clin Radiol ; 79(1): e112-e118, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37872027

RESUMO

AIM: To investigate the prognostic value of the composite posterior circulation Acute Stroke Prognosis Early Computed tomography (CT) Score (ASPECTS)-Collaterals (pcASCO) score, which combines diffusion-weighted imaging (DWI) posterior circulation ASPECTS (pcASPECTS) and the magnetic resonance angiography (MRA)-collateral circulation score at baseline among patients with acute posterior circulation ischaemic stroke after mechanical thrombectomy. MATERIALS AND METHODS: Patients with acute posterior circulation ischaemic stroke who underwent mechanical thrombectomy were analysed retrospectively. The DWI-pcASPECTS and MRA-collateral circulation score before treatment and the modified Rankin Scale (mRS) at 90 days after treatment were used as the endpoints. An mRS ≤2 was defined as a good prognosis, and an mRS ≥3 was defined as a poor prognosis. Multivariate logistic regression was used to analyse independent predictors of functional outcome 90 days after mechanical thrombectomy. RESULTS: Mechanical thrombectomy was performed in 57 patients; 38 patients had a good prognosis, 19 patients had a poor prognosis, and 33 patients were successfully recanalised. Univariate logistic regression found that National Institute of Health Stroke Scale (NIHSS) score (OR: 1.18, p<0.001), pcASPECTS (OR: 1.91, p=0.028) and pcASCO score (OR: 0.51, p=0.001) were factors of good functional outcome. Receiver operating characteristic curve (ROC curve) analysis showed that the diagnostic efficiency of the NIHSS and pcASCO was better (AUC = 0.88, 0.83, p<0.05) than that of the pcASPECTS (AUC = 0.65). The prediction model was established by age, NIHSS, and pcASCO, and the diagnostic efficiency of the prediction model was better (AUC = 0.94). CONCLUSIONS: The composite MR-pcASCO score can be used as an important predictor of the prognosis of patients with acute posterior circulation ischaemic stroke after mechanical thrombectomy.


Assuntos
Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Prognóstico , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/cirurgia , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/cirurgia , Resultado do Tratamento , Estudos Retrospectivos , AVC Isquêmico/diagnóstico por imagem , AVC Isquêmico/cirurgia , Trombectomia/métodos , Espectroscopia de Ressonância Magnética
5.
Tech Coloproctol ; 28(1): 64, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38844577

RESUMO

BACKGROUND: This study aimed to investigate the safety and feasibility of indocyanine green near-infrared fluorescence (ICG-NIR) fluorescence-guided video-endoscopic inguinal lymphadenectomy (VEIL) for rectal cancer with inguinal lymph node metastasis (ILNM). METHODS: A retrospective analysis was conducted on 11 patients with rectal cancer who underwent ICG-NIR fluorescence-guided VEIL, assessing various parameters such as operation time, intraoperative bleeding, number of harvested lymph nodes, intraoperative and postoperative complications, and follow-up. RESULTS: Regarding surgical procedures for ILNM, unilateral surgery was performed in 7 cases (54.5%) and bilateral surgery in 4 cases (45.5%). Among these 15 ICG-NIR-guided VEIL surgeries in 11 patients, positive fluorescence visualization was achieved in 13 operations (86.7%). The median estimated blood loss was 10 ml, and the median operation time was 90 min. One case (6.7%) required conversion to open surgery. The median duration of the drain tube was 12 days, and the median length of postoperative hospital stay was 20 days. Postoperative complications were observed, including incisional infection in 2 cases (18.2%), lymphatic leakage in 5 cases (45.5%), urinary infection in 1 case (9.1%), and pneumonia in 3 cases (27.3%). Complications such as skin necrosis, lower limb venous thrombosis, lower limb swelling, or impaired movement were observed during the postoperative follow-up period. No cases of primary lesion, groin, or pelvic lymph node recurrence were observed. CONCLUSION: ICG-NIR fluorescence-guided VEIL is a safe and feasible surgical treatment for rectal cancer with ILNM. ICG fluorescence guidance holds promise as a more personalized and precise approach for VEIL in rectal cancer surgery.


Assuntos
Estudos de Viabilidade , Verde de Indocianina , Canal Inguinal , Excisão de Linfonodo , Metástase Linfática , Duração da Cirurgia , Neoplasias Retais , Cirurgia Vídeoassistida , Humanos , Neoplasias Retais/cirurgia , Neoplasias Retais/patologia , Masculino , Excisão de Linfonodo/métodos , Feminino , Pessoa de Meia-Idade , Estudos Retrospectivos , Idoso , Cirurgia Vídeoassistida/métodos , Canal Inguinal/cirurgia , Complicações Pós-Operatórias/etiologia , Adulto , Linfonodos/patologia , Linfonodos/cirurgia , Linfonodos/diagnóstico por imagem , Corantes , Fluorescência
6.
Hong Kong Med J ; 30(4): 281-290, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39009479

RESUMO

INTRODUCTION: Human immunodeficiency virus (HIV)-associated tuberculosis (TB) remains an important health challenge worldwide. Although TB prevalence has decreased in the general population, there is limited information regarding temporal trends in the incidence of HIV-associated TB in Hong Kong. There are also insufficient data regarding changes in clinical manifestation patterns among HIV-associated TB patients over time. This study aimed to describe temporal trends in the epidemiology and clinical manifestations of HIV-associated TB in Hong Kong. METHODS: We retrospectively reviewed data regarding HIV-associated TB patients that were reported to the TB-HIV Registry of the Department of Health during the period 2007 to 2020. Trends of TB as a primary acquired immunodeficiency syndrome (AIDS)-defining illness, as well as changes in demographic features and clinical manifestations of HIV-associated TB during this period were examined using Cochran-Armitage trend test. RESULTS: A decreasing trend was observed in the proportion of all reported cases of AIDS in which TB was a primary AIDS-defining illness during the study period. The proportions of female patients and patients with extrapulmonary involvement significantly increased, whereas the proportions of ever-smokers and patients with sputum smear positivity significantly decreased during the same period. A decreasing trend was observed in the proportion of patients with pulmonary TB in which the lower zone was the predominant site of lung parenchymal lesions. Among patients with a diagnosis of HIV infection before TB, an increasing trend was observed in the proportion of patients receiving antiretroviral therapy. CONCLUSION: Important temporal changes were observed in the epidemiology and clinical manifestations of HIV-associated TB. These results highlight the need for continued surveillance regarding the patterns of demographic features and clinical manifestations to inform policymakers when planning control strategies for HIV-associated TB.


Assuntos
Infecções por HIV , Humanos , Hong Kong/epidemiologia , Feminino , Masculino , Estudos Retrospectivos , Adulto , Infecções por HIV/epidemiologia , Infecções por HIV/complicações , Pessoa de Meia-Idade , Incidência , Tuberculose/epidemiologia , Prevalência , Infecções Oportunistas Relacionadas com a AIDS/epidemiologia , Tuberculose Pulmonar/epidemiologia , Adulto Jovem , Sistema de Registros
7.
Cryo Letters ; 45(3): 149-157, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38709186

RESUMO

BACKGROUND: The industrial scale cryo-storage of raw tissue materials requires a robust, low-cost and easy-to-operate method that can facilitate the down-stream process. OBJECTIVE: The study was aimed to develop the multifunctional protective solutions (MPS) for transportation at ambient conditions and also subsequent cryo-storage below -20 degree C of raw porcine hides for tissue engineering and regenerative medicine. MATERIALS AND METHODS: Protective solutions with antimicrobial activity and proteinase-inhibiting activity were developed and tested for its efficacy in preserving the extracellular matrix of porcine dermis from microbial spoilage, proteolytic degradation, freeze damage and excessive dehydration during shipping and cryo-storage. The MPSs contained phosphate-buffered saline with ethylene diamine tetra acetic acid (EDTA) added as chelator and proteinase inhibitor, as well as glycerol or maltodextrin (M180) as cryoprotectants. RESULTS: MPSs prepared with EDTA and glycerol or M180 had significant antimicrobial activity and proteinase-inhibiting activity during the period of shipping and handling. Glycerol and M180 prevented eutectic salt precipitation and excessive freeze dehydration upon cryo-storage of porcine hides. Without glycerol or M180, hides could be freeze-dehydrated to the low hydration at ~0.4 g/g dw, and formed irreversible plications after freezing. A critical hydration (0.8~0.9 g/g dw) was observed for the extracellular matrix of porcine dermis, and dehydration to a lower level could impose enormous stress and potential damage. The soaking of porcine hides in MPSs decreased water content as glycerol and M180 entered into dermis. Upon equilibration, the glycerol content in the tissue was about 94% of the incubating glycerol solution, but the M180 content in the tissue was only about 50% of the incubating M180 solution, indicating that M180 did not get into the entire aqueous domain within dermis. MPSs reduced ice formation and increased the unfrozen water content of porcine raw hides upon cryo-storage. CONCLUSION: MPSs prepared with EDTA and glycerol or M180 have antimicrobial activity and proteinase-inhibiting activity, which can be used for transportation and cryo-storage of raw hides at the industrial scale. Glycerol at 7.5% w/v and M180 at 20% w/v were sufficient to prevent freeze damage and excessive freeze dehydration. Doi.org/10.54680/fr24310110312.


Assuntos
Criopreservação , Crioprotetores , Medicina Regenerativa , Engenharia Tecidual , Animais , Medicina Regenerativa/métodos , Suínos , Engenharia Tecidual/métodos , Criopreservação/métodos , Crioprotetores/farmacologia , Crioprotetores/química , Ácido Edético/química , Ácido Edético/farmacologia , Inibidores de Proteases/farmacologia , Inibidores de Proteases/química , Polissacarídeos/química , Polissacarídeos/farmacologia , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Matriz Extracelular/química , Matriz Extracelular/efeitos dos fármacos
8.
Cryo Letters ; 45(1): 55-59, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38538373

RESUMO

BACKGROUND: Human donor skin is processed to make the acellular dermis matrix (ADM) for tissue repair and regeneration. There is no data on the viscoelastic properties of ADM at room and subzero temperatures. OBJECTIVE: The work evaluated the temperature dependence of viscoelastic properties of freeze-dried ADM. MATERIALS AND METHODS: Donor skin was de-epidermized, de-cellularized and freeze-dried with trehalose as the lyo-protectant. Glass transition of freeze-dried ADM was measured by differential scanning calorimeter (DSC), and viscoelastic properties were examined by dynamic mechanical analyzer (DMA). RESULTS: At the low moisture range (1.4 +/- 0.5%), the glass transition temperature (Tg) of freeze-dried ADM was 90 degree C to 100 degree C. As the moisture content increased, the Tg decreased steadily. At the high moisture range (10.8 +/- 2.9%), the Tg was 40 degree C to 60 degree C. There were large donor-to-donor variations in viscoelastic properties of freeze-dried ADM as demonstrated by the changes in storage modulus (G'), loss modulus (G") and damping factor tan delta (G"/G'). However, the trends of the temperature dependence for G', G" and tan delta were similar among all 8 donors. For each donor, changes in G' and G" were relatively small between -90 degree C and 40 degree C, and G' was at least one order of magnitude greater than G". Two viscoelastic relaxations were observed in freeze-dried ADM, one at -20 degree C and the other at -60 degree C respectively. CONCLUSION: Freeze-dried ADM was protected in the glassy carbohydrate matrix. DMA observed two viscoelastic relaxations (i.e., alpha process at -20 degree C and beta process at -60 degree C). Overall changes in G' and G'' of freeze-dried ADM were relatively small within one order of magnitude between -90 degree C and 40 degree C. https://doi.org/10.54680/fr24110110612.


Assuntos
Derme Acelular , Criopreservação , Humanos , Temperatura , Congelamento , Liofilização
9.
J Ment Health ; 33(3): 386-393, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38845178

RESUMO

BACKGROUND: Mental illnesses and mental health challenges have become increasingly pervasive among Chinese university students. However, the utilization rate of mental health services is low among students. AIMS: We aimed to explore Chinese university students' help-seeking behaviors to understand how they deal with mental health challenges and use the results to inform the development of effective mental health promotion initiatives. METHODS: In this study, we conducted 13 focus group interviews with students in six universities in Jinan, China, including 91 (62%) female students and 56 (38%) male students. We drew on the Theory of Planned Behaviors to guide our thematic analysis to gain a contextual understanding of participants' accounts on help-seeking. RESULTS: Our results have depicted the help-seeking patterns of Chinese university students and show that there are four major behaviors which are self-reliance, seeking support from peers and families, seeking professional support, and accessing virtual mental health care. CONCLUSION: Results from this study can be used to inform the development of mental health literacy programming for students in universities that share similar contexts, and the study has also opened up a new space for using qualitative approaches to study mental health needs and access to care in diverse populations.


Assuntos
Comportamento de Busca de Ajuda , Transtornos Mentais , Serviços de Saúde Mental , Estudantes , Humanos , Feminino , Masculino , Estudantes/psicologia , Universidades , Adulto Jovem , China , Transtornos Mentais/terapia , Transtornos Mentais/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Adulto , Grupos Focais , Saúde Mental , Adolescente
10.
Zhonghua Yi Xue Za Zhi ; 104(29): 2759-2766, 2024 Jul 30.
Artigo em Chinês | MEDLINE | ID: mdl-39075996

RESUMO

Objective: To summarize the long-term efficacy of Beijing Children's Hospital-2009-lymphoblastic lymphoma (BCH-2009-LBL) in the treatment of T-lymphoblastic lymphoma (T-LBL) in children and adolescents and to explore the prognostic factors. Methods: T-LBL children admitted to Beijing Children's Hospital Affiliated to Capital Medical University from January 2009 to April 2017 were retrospectively included. According to clinical stage, prognostic genes and treatment response, the children were divided into low, intermediate and high risk groups, and stratified treatment was performed according to the BCH-2009-LBL protocol, with follow-up until December 31, 2023. The clinical characteristics and therapeutic effect of each group were compared. Survival curve was drawn by Kaplan-Meier method, and the difference in survival rate between groups was compared by log-rank test. Multivariate Cox regression model was used to analyze the prognostic factors. Results: A total of 146 patients were included, the age of disease onset [M(Q1, Q3)] was 8.0 (1.5, 14.0) years old. There were 107 (73.3%) males and 39 (26.7%) females. Clinical staging: 1 case in stage Ⅰ and 1 case in stage Ⅱ (0.7% each), 41 cases (28.1%) cases in stage Ⅲ and 103 cases(70.5%) in stage Ⅳ. There were 1 case (0.7%), 93 cases (63.7%), and 52 cases (35.6%) in the low, intermediate, and high-risk groups, respectively. The follow-up time was 121 (80, 180) months, and the 5-year and 10-year event-free survival (EFS) rates were 76.4% and 75.0%, respectively. The 5-year EFS rates of low, intermediate and high risk groups were 100.0%, 81.3% and 67.3%, respectively. There was significant difference in remission between the middle-risk group and the high-risk group on the 8th day of hormone pretreatment and at the end of induction (both P<0.05). Recurrence/progression occurred in 29 cases (recurrence rate 19.9%), and the recurrence time was 15 (3, 74) months, in which 26 cases died and only 3 cases survived. Infection-related death occurred in 6 cases (4.1%). The failure or progression of hormone pretreatment at d8 (HR=10.089, 95%CI: 1.266-80.387, P=0.029) and the failure to achieve complete remission at the end of induction (mid-term evaluation) (HR=7.638, 95%CI: 2.411-24.199, P=0.001) were the risk factors for EFS rate of intermediate risk group. The above indexes had no statistical significance on EFS rate in high-risk groups (all P>0.05). Conclusions: BCH-2009-LBL regimen shows good efficacy in the treatment of pediatric T-LBL. The failure or progression of hormone pretreatment at d8 and the failure to achieve complete remission at the end of induction (mid-term evaluation) were the risk factors for EFS rate.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Humanos , Criança , Feminino , Masculino , Adolescente , Prognóstico , Estudos Retrospectivos , Pré-Escolar , Pequim , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Lactente , Resultado do Tratamento , Hospitais Pediátricos , Taxa de Sobrevida , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia
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