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1.
Nanotechnology ; 33(27)2022 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-35276687

RESUMO

The negative Poisson's ratio (NPR) is a novel property of materials, which enhances the mechanical feature and creates a wide range of application prospects in lots of fields, such as aerospace, electronics, medicine, etc. Fundamental understanding on the mechanism underlying NPR plays an important role in designing advanced mechanical functional materials. However, with different methods used, the origin of NPR is found different and conflicting with each other, for instance, in the representative graphene. In this study, based on machine learning technique, we constructed a moment tensor potential for molecular dynamics (MD) simulations of graphene. By analyzing the evolution of key geometries, the increase of bond angle is found to be responsible for the NPR of graphene instead of bond length. The results on the origin of NPR are well consistent with the start-of-art first-principles, which amend the results from MD simulations using classic empirical potentials. Our study facilitates the understanding on the origin of NPR of graphene and paves the way to improve the accuracy of MD simulations being comparable to first-principle calculations. Our study would also promote the applications of machine learning interatomic potentials in multiscale simulations of functional materials.

2.
Phys Chem Chem Phys ; 24(29): 17479-17484, 2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35822513

RESUMO

The two-dimensional (2D) materials, represented by graphene, stand out in the electrical industry applications of the future and have been widely studied. As commonly existing in electronic devices, the electric field has been extensively utilized to modulate the performance. However, how the electric field regulates thermal transport is rarely studied. Herein, we investigate the modulation of thermal transport properties by applying an external electric field ranging from 0 to 0.4 V Å-1, with bilayer graphene, monolayer silicene, and germanene as study cases. The monotonically decreasing trend of thermal conductivity in all three materials is revealed. A significant effect on the scattering rate is found to be responsible for the decreased thermal conductivity driven by the electric field. Further evidence shows that the reconstruction of internal electric field and generation of induced charges lead to increased scattering rate from strong phonon anharmonicity. Thus, the ultralow thermal conductivity emerges with the application of external electric fields. Applying an external electric field to regulate thermal conductivity illustrates a constructive idea for highly efficient thermal management.

3.
Crit Care ; 24(1): 438, 2020 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-32678040

RESUMO

BACKGROUND: Coronavirus disease 2019 (COVID-19) has become a public health emergency of global concern. We aimed to explore the risk factors of 14-day and 28-day mortality and develop a model for predicting 14-day and 28-day survival probability among adult hospitalized patients with COVID-19. METHODS: In this multicenter, retrospective, cohort study, we examined 828 hospitalized patients with confirmed COVID-19 hospitalized in Wuhan Union Hospital and Central Hospital of Wuhan between January 12 and February 9, 2020. Among the 828 patients, 516 and 186 consecutive patients admitted in Wuhan Union Hospital were enrolled in the training cohort and the validation cohort, respectively. A total of 126 patients hospitalized in Central Hospital of Wuhan were enrolled in a second external validation cohort. Demographic, clinical, radiographic, and laboratory measures; treatment; proximate causes of death; and 14-day and 28-day mortality are described. Patients' data were collected by reviewing the medical records, and their 14-day and 28-day outcomes were followed up. RESULTS: Of the 828 patients, 146 deaths were recorded until May 18, 2020. In the training set, multivariate Cox regression indicated that older age, lactate dehydrogenase level over 360 U/L, neutrophil-to-lymphocyte ratio higher than 8.0, and direct bilirubin higher than 5.0 µmol/L were independent predictors of 28-day mortality. Nomogram scoring systems for predicting the 14-day and 28-day survival probability of patients with COVID-19 were developed and exhibited strong discrimination and calibration power in the two external validation cohorts (C-index, 0.878 and 0.839). CONCLUSION: Older age, high lactate dehydrogenase level, evaluated neutrophil-to-lymphocyte ratio, and high direct bilirubin level were independent predictors of 28-day mortality in adult hospitalized patients with confirmed COVID-19. The nomogram system based on the four factors revealed good discrimination and calibration, suggesting good clinical utility.


Assuntos
Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/terapia , Modelos Estatísticos , Pneumonia Viral/mortalidade , Pneumonia Viral/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19 , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Prognóstico , Reprodutibilidade dos Testes , Estudos Retrospectivos , Fatores de Risco , Análise de Sobrevida
4.
Bioorg Chem ; 104: 104257, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32927129

RESUMO

BACKGROUND: Oseltamivir is a first-line antiviral drug, especially in primary hospitals. During the ongoing outbreak of coronavirus disease 2019 (COVID-19), most patients with COVID-19 who are symptomatic have used oseltamivir. Considering its popular and important role as an antiviral drug, it is necessary to evaluate oseltamivir in the treatment of COVID-19. OBJECTIVE: To evaluate the effect of oseltamivir against COVID-19. METHODS: Swiss-model was used to construct the structure of the N-terminal RNA-binding domain (NRBD) of the nucleoprotein (NC), papain-like protease (PLpro), and RNA-directed RNA polymerase (RdRp) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). TM-align program was performed to compare the structure of the viral proteins with the structure of the neuraminidase of influenza A. Molecular docking was used to analyze the theoretical possibility of effective binding of oseltamivir with the active centers of the viral proteins. In vitro study was used to evaluate the antiviral efficiency of oseltamivir against SARS-CoV-2. By clinical case analysis, we statistically evaluated whether the history of oseltamivir use influenced the progression of the disease. RESULTS: The structures of NRBD, PLpro, and RdRp were built successfully. The results from TM-align suggested that the S protein, NRBD, 3C-like protease (3CLpro), PLPrO, and RdRp were structurally similar to the influenza A neuraminidase, with TM-scores of 0.30077, 0.19254, 0.28766, 0.30666, and 0.34047, respectively. Interestingly, the active center of 3CL pro was found to be similar to the active center from the neuraminidase of influenza A. Through an analysis of molecular docking, we discovered that oseltamivir carboxylic acid was more favorable to bind to the active site of 3CLpro effectively, but its inhibitory effect was not strong compared with the positive group. Finally, we used in vitro study and retrospective case analysis to verify our speculations. We found that oseltamivir is ineffective against SARS-CoV-2 in vitro study and the clinical use of oseltamivir did not improve the patients' symptoms and signs and did not slow the disease progression. CONCLUSIONS: We consider that oseltamivir isn't suitable for the treatment of COVID-19. During the outbreak of novel coronavirus, when oseltamivir is not effective for the patients after they take it, health workers should be highly vigilant about the possibility of COVID-19.


Assuntos
Antivirais/uso terapêutico , Tratamento Farmacológico da COVID-19 , Oseltamivir/uso terapêutico , SARS-CoV-2/efeitos dos fármacos , Adulto , Idoso , Animais , Antivirais/química , Antivirais/metabolismo , Domínio Catalítico , Chlorocebus aethiops , Proteases 3C de Coronavírus/antagonistas & inibidores , Proteases 3C de Coronavírus/química , Proteases 3C de Coronavírus/metabolismo , Proteínas do Nucleocapsídeo de Coronavírus/química , Proteínas do Nucleocapsídeo de Coronavírus/metabolismo , Inibidores de Cisteína Proteinase/metabolismo , Inibidores de Cisteína Proteinase/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Simulação de Acoplamento Molecular , Oseltamivir/química , Oseltamivir/metabolismo , Fosfoproteínas/química , Fosfoproteínas/metabolismo , Ligação Proteica , RNA Polimerase Dependente de RNA/química , RNA Polimerase Dependente de RNA/metabolismo , Estudos Retrospectivos , Células Vero
5.
Br J Dermatol ; 175(6): 1204-1209, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27087313

RESUMO

BACKGROUND: Inherited epidermodysplasia verruciformis (EV) is a rare skin disorder characterized by susceptibility to specific types of human papilloma virus (HPV) and is strongly associated with skin carcinomas. Inactivating mutations in EVER1/EVER2 account for most cases of EV. However, more phenotypes related to but distinct from EV have been reported with an immunodeficiency state but without EVER1/EVER2 mutation, and the genetic basis for these atypical EV cases is poorly understood. OBJECTIVES: To identify the causative gene responsible for three siblings affected by atypical EV but without EVER1/EVER2 mutation. METHODS: Whole-exome sequencing followed by Sanger sequencing was performed to identify the gene responsible for the patients with atypical EV enrolled in our study. RESULTS: A homozygous splicing mutation was detected in LCK (c.188-2A>G). This mutation resulted in an exon 3 deletion T lymphocyte-specific protein tyrosine kinase isoform, which further led to frameshift mutation and subsequent mRNA decay. CONCLUSIONS: We demonstrate a novel mutation in LCK in a family affected by atypical EV with T-cell defects, HPV infection and virus-induced malignancy, providing new clues in the understanding of host defences against HPV and better genetic counselling of patients with the EV phenotype.


Assuntos
DNA Recombinante/genética , Epidermodisplasia Verruciforme/genética , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/metabolismo , Mutação/genética , Infecções por Papillomavirus/genética , Dermatopatias/genética , Adolescente , Feminino , Homozigoto , Humanos , Masculino , Linhagem , Adulto Jovem
6.
Plant Dis ; 98(5): 696, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-30708544

RESUMO

Alocasia macrorrhiza (L.) Schott. (Araceae), native to South America, is a common, herbaceous perennial ornamental plant in tropical and subtropical areas (1). A severe leaf spot disease was observed on this plant in several places on the campus of authors' university in Guangzhou, Guangdong Province, China, in April 2013. Initial symptoms were water-soaked, dark green leaf spots. These small spots gradually expanded to 6- to 11-mm circular lesions. They were grayish-white in color with a yellow halo and many small, black, concentric dots were observed on them. Microscopic examination revealed that these small dots were acervuli, which were 100 to 300 µm in diameter, developing beneath the epidermis and becoming erumpent with age. By using routine tissue-isolation method and single-spore purification technique, four single-conidial isolates were obtained from each of four diseased leaves. These isolates formed a grayish-white colony with numerous pink spore masses on PDA at 28°C. Their mycelial radial growth rate was about 4.5 mm per day. Conidia were single-celled, hyaline, and cylindrical with an obtuse apex and protruding base; they were 12.7 to 14.2 × 4.8 to 5.9 µm in size. Conidial appressoria were irregular in shape, sepia to dark brown, solitary, and 6.9 to 8.5 × 4.6 to 5.9 µm. These morphological characteristics were consistent with the description of Colletotrichum karstii (2). The sequences of beta-tubulin gene (TUB2) and partial actin gene (ACT) of a representative isolate CAM1 were obtained by PCR amplification with primers BT2a/BT2b and ACT512F/ACT783R, respectively. These sequences were deposited in GenBank under the accession numbers of KF444947 and KF460435. BLAST searches showed a 99% homology with the TUB2 and ACT sequences of C. karstii (JX625209, KC843559). Therefore, the fungus isolated from A. macrorrhiza was identified as C. karstii by morphological and molecular characteristics. Pathogenicity tests were performed on 30-day-old plants of A. macrorrhiza grown in plastic pots (0.8 L) by spraying 15 ml conidial suspension (1 × 106 conidia ml-1) of this fungus onto each plant. The control plants were sprayed only with sterile distilled water. These plants then were placed in an intelligent artificial climate incubator with 12-h photoperiod and 100% relative humidity at 24 ± 1°C. Three replicates, each with five plants, were included in a test, and the test was repeated twice. Seven days after inoculation, the inoculated plants showed necrotic lesions on leaves similar to those observed on the campus, but no symptoms were observed on any non-inoculated controls. The same fungus C. karstii was re-isolated from the infected leaves. Although C. karstii is a well-known anthracnose pathogen on some plants belonging to family Orchidaceae (2), this is the first report of the same pathogen causing anthracnose on A. macrorrhiza in Guangdong, China. References: (1) S. Li et al. PLoS ONE 8(6):e66016, 2013. (2) Y. Yang et al. Cryptogr. Mycol. 32:229, 2011.

7.
Plant Dis ; 98(3): 426, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30708429

RESUMO

Eggplant (Solanum melongena L.) is an economically important vegetable crop worldwide. In August 2012, severe stem cankers were observed on eggplant at the early stage of maturation in several fields in Guangdong Province, China. Diseased plants raised cankers on the stems and branches, which resulted in wilting and stunting. No symptoms developed on eggplant fruit. Disease incidence was as high as 40% within affected fields. By using routine fungal-isolation methods and single-spore purification technique, five single-conidial isolates were obtained from each diseased stem. Colonies were grayish-white, circular, and got yellow pigmentation when placed in acidified potato dextrose agar (PDA) in an incubator at pH 4.5 and 25°C with a 12-h photoperiod. Stromata were black, large, and spreading in a concentric pattern. Conidiomata were pycnidial, and the pycnidia were round, oblate, triangular or irregular, and unilocular. Conidiophores were colorless, separated, dichotomous, and 10.0 to 18.0 × 1.5 to 2.0 µm. Alpha conidia were single-celled, ellipsoidal to fusiform, guttulate, and 6.0 to 8.0 × 2.0 to 2.5 µm. Beta conidia, produced on oat meal agar in 2 weeks at 25°C in the dark, were filiform, hamate, and 16.0 to 28.0 × 0.7 to 1.0 µm. Based on these morphological characters, the fungus was identified as Phomopsis longicolla Hobbs (1). The ITS-rDNA sequence (GenBank Accession No. KC886605) of the isolate EPPL1 of this fungus (P. longicolla EPPL1) was obtained by using universal primers ITS5/ITS4 (1). BLAST searches showed a 98% homology with the sequence of the ITS region of rDNA of P. longicolla. Phylogenetic analysis showed that P. longicolla EPPL1 clustered with P. longicolla SYJM15 and formed a distinct clade distantly related to P. vexans PV3 (GU373630), a well-known pathogen of eggplant. Digestion of PCR-amplified DNA with Alu I yielded two restriction fragments of sizes consistent with those reported for P. longicolla (2). Pathogenicity tests were performed on 30-day-old plants of cv. Yuefengzihongqie grown in a plastic pot (1 liter) in a greenhouse by using mycelial plugs and conidial suspensions of isolate EPPL1 as inocula. A mycelial plug (4 mm in diameter) from a 7-day-old PDA culture was placed on stems of both wounded and non-wounded plants and covered with sterile absorbent cotton moistened with sterile distilled water. Both wounded and non-wounded plants were inoculated with 0.5 ml of conidial suspension (1 × 106 conidia ml-1) dropped onto sterile absorbent cotton covering the stems. Control assays were performed with agar plugs and sterile distilled water only. Inoculated plants were placed in a greenhouse with a 12-h photoperiod at 28°C. Each treatment was replicated on five plants, and the test was repeated. Twenty-five days after inoculation, both wounded and non-wounded plants inoculated with either method showed raised cankers at the points of inoculation and canker lesions similar to those observed in the field expanded up and down the stems to reach lengths of 15 to 30 mm. Later, sparse, small, black pycnidia formed on the surface of the lesions. The inoculated plants exhibited stunting and premature senescence compared to controls. P. longicolla was re-isolated from the infected stems of inoculated plants. Control plants were asymptomatic. To our knowledge, this is the first report of P. longicolla causing stem canker in eggplant in Guangdong, China. Considering the economic importance of eggplant in Guangdong Province and throughout the world, further study of phomopsis stem canker of eggplant is warranted. References: (1) T. W. Hobbs et al. Mycologia 77:535, 1985. (2) A. W. Zhang et al. Plant Dis. 81:1143, 1997.

8.
Plant Dis ; 98(11): 1583, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30699820

RESUMO

Camellia azalea Wei (Theaceae) is a critically endangered species with high ornamental value in China. Its wild individual plants, less than 1,000, are only found in Yangchun, Guangdong Province, China. Since 2010, a severe dieback on C. azalea has been observed in several commercial plantations in Foshan, Guangdong Province, during the process of artificial propagation. The infection started from the middle portion of the new shoots, where necrosis spots developed and expanded to girdle the stems. Consequently, the shoots died and became brown in color. Later, the necrotic spots turned pale gray, and many small, black fruiting bodies emerged. In the end, more than half of the dead shoots broke off from the necrotic spots. Generally, about 10 to 20% new shoots were infected for one individual plant. Although the older branches with leaves were not infected and showed no symptoms, the dieback of crown outer layer greatly reduced the ornamental value of the plants and the sale price went down. Another part of the plants that is often infected is the stalk, resulting in the drop of fruits. By using routine isolation methods and single-spore purification technique, 18 single-conidial isolates with similar colony morphology were obtained from five diseased plants. The cultures of single-conidial isolates grew at an average rate of 6.8 mm per day on PDA at 28°C. The central part of colony became gray-green with age, and acervuli formed on the medium after incubation for 7 to 10 days. Conidia, round at both ends, were 13.65 to 18.3 × 3.61 to 5.92 µm (avg. = 16.1 ± 1.6 × 4.8 ± 0.8 µm, n = 50) in size. After culturing for 50 to 60 days, perithecia matured. Ascopores were hyaline, straight, aseptate, and 10.02 to 13.77 × 3.27 to 4.45 µm (avg. = 12.2 ± 1.1 × 3.9 ± 0.4 µm, n = 50) in size. The cultural and morphological characteristics of these isolates are consistent with the description of Glomerella cingulata f. sp. camelliae (1). The sequences (GenBank Accession Nos. KJ668576, KJ668577, KJ676642, KJ689374, KJ689375, and KJ689376) of ITS, GPDH, GS, actin, ß-tubulin, and CAL regions of three representative isolates are identical and share 99, 99, 100, 99, 100, and 100% identity with those of the type specimen of G. cingulata f. sp. camelliae ICMP 10643 (JX010224, JX009908, JX010119, JX009540, JX010436, and JX009630), respectively (2). Twenty randomly selected shoots with young leaves on the top of them, detached from different trees, were scratched in the middle part with a fine scalpel to generate a 5-mm-long wound, 50 µl conidial suspension (1 × 105 conidia ml-1) was then dropped onto the wound for inoculation. The control shoots were inoculated with the same volume of sterile distilled water. All inoculated shoots were placed into an intelligent artificial climate incubator with 12-h photoperiod and 100% relative humidity at 28 ± 1°C. Each treatment replicated on five shoots, and the tests were repeated twice. Symptoms resembling those in the field were observed on all conidia-inoculated shoots after 10 to 14 days, and control shoots were asymptomatic. The same fungus G. cingulata f. sp. camelliae was consistently re-isolated from the diseased shoots, fulfilling Koch's postulates. G. cingulata f. sp. camelliae has been reported on other species of Camellia outside China, but this is the first report in China where the species is endemic and endangered (1,2). References: (1) J. S. W. Dickens et al. Plant Pathol. 38:75, 1989. (2) B. Weir et al. Stud Mycol. 73:115, 2012.

9.
Front Pharmacol ; 15: 1181183, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38464717

RESUMO

Traditional Chinese medicine (TCM) is the practical experience and summary of the Chinese nation for thousands of years. It shows great potential in treating various chronic diseases, complex diseases and major infectious diseases, and has gradually attracted the attention of people all over the world. However, due to the complexity of prescription and action mechanism of TCM, the development of TCM industry is still in a relatively conservative stage. With the rise of artificial intelligence technology in various fields, many scholars began to apply artificial intelligence technology to traditional Chinese medicine industry and made remarkable progress. This paper comprehensively summarizes the important role of artificial intelligence in the development of traditional Chinese medicine industry from various aspects, including new drug discovery, data mining, quality standardization and industry technology of traditional Chinese medicine. The limitations of artificial intelligence in these applications are also emphasized, including the lack of pharmacological research, database quality problems and the challenges brought by human-computer interaction. Nevertheless, the development of artificial intelligence has brought new opportunities and innovations to the modernization of traditional Chinese medicine. Integrating artificial intelligence technology into the comprehensive application of Chinese medicine industry is expected to overcome the major problems faced by traditional Chinese medicine industry and further promote the modernization of the whole traditional Chinese medicine industry.

10.
Nat Commun ; 15(1): 2540, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38528017

RESUMO

High-efficient heat dissipation plays critical role for high-power-density electronics. Experimental synthesis of ultrahigh thermal conductivity boron arsenide (BAs, 1300 W m-1K-1) cooling substrates into the wide-bandgap semiconductor of gallium nitride (GaN) devices has been realized. However, the lack of systematic analysis on the heat transfer across the GaN-BAs interface hampers the practical applications. In this study, by constructing the accurate and high-efficient machine learning interatomic potentials, we perform multiscale simulations of the GaN-BAs heterostructures. Ultrahigh interfacial thermal conductance of 260 MW m-2K-1 is achieved, which lies in the well-matched lattice vibrations of BAs and GaN. The strong temperature dependence of interfacial thermal conductance is found between 300 to 450 K. Moreover, the competition between grain size and boundary resistance is revealed with size increasing from 1 nm to 1000 µm. Such deep-potential equipped multiscale simulations not only promote the practical applications of BAs cooling substrates in electronics, but also offer approach for designing advanced thermal management systems.

11.
Cell Biosci ; 14(1): 100, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39090653

RESUMO

BACKGROUND: Immunosurveillance is pivotal in the effectiveness of anticancer therapies and tumor control. The ineffectiveness of cisplatin in activating the immunosurveillance is attributed to its lack of adjuvanticity resulting from its inability to stimulate endoplasmic reticulum stress. Dihydroartemisinin demonstrates the anti-tumor effects through various mechanisms, including the activation of the endoplasmic reticulum stress. This study aimed to develop a novel strategy to enhance the immunogenicity of dying tumor cells by combining cisplatin with dihydroartemisinin, thereby triggering effective anti-tumor immunosurveillance and improving the efficacy of cisplatin in clinical practice. METHODS: Lewis lung carcinoma (LLC) and CT26 colon cancer cell lines and subcutaneous tumor models were used in this study. The importance of immunosurveillance was validated in both immunocompetent and immunodeficient mouse models. The ability of dihydroartemisinin and cisplatin therapy to induce immunogenic cell death and tumor growth control in vivo was validated by prophylactic tumor vaccination and therapeutic tumor models. The underlying mechanism was elucidated through the pharmaceutical or genetic intervention of the PERK/eIF2α pathway in vitro and in vivo. RESULTS: Dihydroartemisinin enhanced the generation of reactive oxygen species in cisplatin-treated LLC and CT26 cancer cells. The combination treatment of dihydroartemisinin with cisplatin promoted cell death and ensured an optimal release of damage-associated molecular patterns from dying cancer cells, promoting the phagocytosis of dendritic cells. In the tumor vaccination model, we confirmed that dihydroartemisinin plus cisplatin treatment induced immunogenic cell death. Utilizing immunocompetent and immunodeficient mouse models, we further demonstrated that the combination treatment suppressed the tumor growth of CT26 colon cancer and LLC lung cancer, leading to an improved prognosis through the restoration of cytotoxic T lymphocyte responses and reinstatement of anti-cancer immunosurveillance in vivo. Mechanistically, dihydroartemisinin restored the immunogenicity of cisplatin by activating the adjuvanticity of damage-associated molecular patterns, such as calreticulin exposure, through the PERK/eIF2α pathway. Additionally, the inhibition of eIF2α phosphorylation attenuated the anti-tumor efficiency of C + D in vivo. CONCLUSIONS: We highlighted that dihydroartemisinin acts as an immunogenic cell death rescuer for cisplatin, activating anticancer immunosurveillance in a PERK/eIF2α-dependent manner and offering a strategy to enhance the anti-tumor efficacy of cisplatin in clinical practice.

13.
Proc Natl Acad Sci U S A ; 106(26): 10632-7, 2009 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-19520830

RESUMO

Mechanical robustness of the cell under different modes of stress and deformation is essential to its survival and function. Under tension, mechanical rigidity is provided by the cytoskeletal network; with increasing stress, this network stiffens, providing increased resistance to deformation. However, a cell must also resist compression, which will inevitably occur whenever cell volume is decreased during such biologically important processes as anhydrobiosis and apoptosis. Under compression, individual filaments can buckle, thereby reducing the stiffness and weakening the cytoskeletal network. However, the intracellular space is crowded with macromolecules and organelles that can resist compression. A simple picture describing their behavior is that of colloidal particles; colloids exhibit a sharp increase in viscosity with increasing volume fraction, ultimately undergoing a glass transition and becoming a solid. We investigate the consequences of these 2 competing effects and show that as a cell is compressed by hyperosmotic stress it becomes progressively more rigid. Although this stiffening behavior depends somewhat on cell type, starting conditions, molecular motors, and cytoskeletal contributions, its dependence on solid volume fraction is exponential in every instance. This universal behavior suggests that compression-induced weakening of the network is overwhelmed by crowding-induced stiffening of the cytoplasm. We also show that compression dramatically slows intracellular relaxation processes. The increase in stiffness, combined with the slowing of relaxation processes, is reminiscent of a glass transition of colloidal suspensions, but only when comprised of deformable particles. Our work provides a means to probe the physical nature of the cytoplasm under compression, and leads to results that are universal across cell type.


Assuntos
Tamanho Celular , Citoplasma/metabolismo , Células Eucarióticas/citologia , Óculos , Actinas/metabolismo , Algoritmos , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Linhagem Celular , Linhagem Celular Tumoral , Células Cultivadas , Coloides , Citocalasina D/farmacologia , Citoplasma/efeitos dos fármacos , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/metabolismo , Células Eucarióticas/efeitos dos fármacos , Células Eucarióticas/metabolismo , Análise de Elementos Finitos , Humanos , Soluções Hipertônicas/farmacologia , Técnicas In Vitro , Microscopia de Força Atômica , Microscopia de Fluorescência , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Músculo Liso/fisiologia , Pressão Osmótica , Polietilenoglicóis/farmacologia , Ovinos , Estresse Mecânico , Tiazolidinas/farmacologia
14.
Front Public Health ; 10: 907474, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35812478

RESUMO

The Instant Delivery Service (IDS) riders' overwork by "self-pressurisation" will not only reduce the level of their physical and mental health but also lose their lives in safety accidents caused by their fatigue riding. The purpose of this article is to examine whether there is overwork among IDS riders in big and medium cities in China? What's going on with them? Based on the Cobb-Douglas production function in the input-output theory, this study characterised the factors on IDS riders' safety and health associated with labour intensity. A mediating model with moderating effect was adopted to describe the mediation path for the 2,742 IDS riders who were surveyed. The results of moderating regression demonstrated that (1) 0.4655 is the total effect of labour intensity on the safety and health of IDS riders. (2) 0.3124 is the moderating effect that working hours make a greater impact on labour intensity. (3) The mediating effect of work pressure is the principal means of mediation both upstream and downstream.


Assuntos
Análise de Mediação , China , Cidades , Inquéritos e Questionários
15.
J Racial Ethn Health Disparities ; 9(4): 1325-1334, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-34160819

RESUMO

The current study sought to understand the influence of cultural values on mental health attitudes and help-seeking behaviors in college students of diverse ethnic backgrounds. Asian and Latinx college students (N = 159) completed an online survey in which they reported on their adherence to cultural values as measured by ethnicity-specific cultural values and general attitudes towards mental health. Factor analysis revealed two common factors of cultural values irrespective of ethnicity: Interdependent Orientation (IO) and Cultural Obligation (CO). Regardless of ethnicity, the more students endorsed IO values, the less likely they were to perceive a need for mental health treatment. IO value adherence was also predictive of more negative attitudes towards mental health. CO values were not predictive of perceived need or help-seeking behaviors. Findings highlight the importance of understanding shared cultural values across ethnic-racial groups and considering how the multidimensionality of culture may help explain shared mental health behaviors crossing lines of ethnic group membership.


Assuntos
Comportamento de Busca de Ajuda , Saúde Mental , Atitude Frente a Saúde , Humanos , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Estudantes
16.
Neurologist ; 27(6): 313-318, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-35184120

RESUMO

BACKGROUND: We conducted this study to assess the value of clinically relevant data for predicting the failure of removing urinary catheters among patients with intracerebral hemorrhage postoperatively. MATERIALS AND METHODS: We retrospectively analyzed the medical records of all patients with intracerebral hemorrhage who underwent surgery for removal of intracerebral hematoma between January 2014 and December 2019, all of whom retained their urinary catheter. The patients were classified into 2 groups. Group A included patients who underwent successful removal of the catheter while group B included patients who underwent a failed removal. Univariate analysis was performed to determine the relationship between the failure of catheter removal and the patients' preoperative clinical characteristics. Independent prognostic predictors were identified using multivariate analyses. RESULTS: The site of intracerebral hematoma ( P =0.004), volume of hematoma ( P <0.001), intraventricular hemorrhage ( P <0.001), admitted Glasgow Coma Scale (GCS) ( P <0.001), GCS before urinary catheter removal ( P <0.001), smoking ( P =0.011), herniation ( P <0.001), urine protein ( P =0.013), creatinine ( P =0.037), and timing of urinary catheter removal ( P <0.001) were significantly different among the 2 groups. Multiple logistical regression analysis indicated that GCS before urinary catheter removal (odds ratio=1.171; 95% confidence interval=1.050-1.306; P =0.005) and timing for urinary catheter removal (odds ratio=0.962; 95% confidence interval=0.944-0.981; P <0.001) were associated with failure of urinary catheter removal. CONCLUSIONS: This study demonstrated that GCS before urinary catheter removal and the timing of urinary catheter removal are independent factors associated with failure of urinary catheter removal among patients with intracerebral hemorrhage.


Assuntos
Hemorragia Cerebral , Cateteres Urinários , Humanos , Estudos Retrospectivos , Hemorragia Cerebral/complicações , Hemorragia Cerebral/cirurgia , Hematoma/cirurgia , Hematoma/complicações , Escala de Coma de Glasgow
17.
Int J Nanomedicine ; 17: 6113-6129, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36514377

RESUMO

Extracellular vesicles (EVs) can contain DNA, RNA, proteins and metabolic molecules from primary origins; they are coated with a phospholipid bilayer membrane and released by cells into the extracellular matrix. EVs can be obtained from various body liquids, including the blood, saliva, cerebrospinal fluid, and urine. As has been proved, EVs-mediated transfer of biologically active molecules is crucial for various physiological and pathological processes. Extensive investigations have already begun to explore the diagnosis and prognosis potentials for EVs. Furthermore, research has continued to recognize the critical role of nucleic acids and proteins in EVs. However, our understanding of the comprehensive effects of metabolites in these nanoparticles is currently limited and in its infancy. Therefore, we have attempted to summarize the recent research into the metabolomics of EVs in relation to potential clinical applications and discuss the problems and challenges that have occurred, to provide more guidance for the future development in this field.


Assuntos
Vesículas Extracelulares , Ácidos Nucleicos , Vesículas Extracelulares/metabolismo , Metabolômica , Ácidos Nucleicos/metabolismo , Prognóstico , DNA/metabolismo , Proteínas/metabolismo
18.
Front Oncol ; 12: 1008283, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36530971

RESUMO

Introduction: Tyrosine kinase inhibitors (TKIs) that target epidermal growth factor receptor (EGFR) mutations are commonly administered to EGFR-positive lung cancer patients. However, resistance to EGFR-TKIs (mostly gefitinib and erlotinib) is presently a significant problem. Limited studies have focused on an EGFR-TKI resistance-related gene signature (ERS) in lung adenocarcinoma (LUAD). Methods: Gefitinib and erlotinib resistance-related genes were obtained through the differential analyses of three Gene Expression Omnibus datasets. These genes were investigated further in LUAD patients from The Cancer Genome Atlas (TCGA). Patients in the TCGA-LUAD cohort were split into two groups: one for training and one for testing. The training cohort was used to build the ERS, and the testing cohort was used to test it. GO and KEGG analyses were explored for the enriched pathways between the high-risk and low-risk groups. Various software, mainly CIBERSORT and ssGSEA, were used for immune infiltration profiles. Somatic mutation and drug sensitivity analyses were also explored. Results: An ERS based on five genes (FGD3, PCDH7, DEPDC1B, SATB2, and S100P) was constructed and validated using the TCGA-LUAD cohort, resulting in the significant stratification of LUAD patients into high-risk and low-risk groups. Multivariable Cox analyses confirmed that ERS had an independent prognostic value in LUAD. The pathway enrichment analyses showed that most of the genes that were different between the two risk groups were related to the immune system. Further immune infiltration results revealed that a lower immune infiltration score was observed in high-risk patients, and that various leukocytes were significantly related to the ERS. Importantly, samples from the high-risk group showed lower levels of PD-1, PD-L1, and CTLA-4, which are important biomarkers for immunotherapy responses. Patients in the high-risk group also had more gene mutation changes and were more sensitive to chemotherapy drugs like docetaxel and sorafenib. The ERS was also validated in the GSE30219, GSE11969 and GSE72094, and showed a favorable prognostic value for LUAD patients. Discussion: The ERS established during this study was able to predict a poor prognosis for LUAD patients and had great potential for predicting drug responses.

19.
Cancers (Basel) ; 14(20)2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36291889

RESUMO

Lung adenocarcinoma (LUAD) is the primary histological subtype of lung cancer with a markedly heterogeneous prognosis. Therefore, there is an urgent need to identify optimal prognostic biomarkers. We aimed to explore the value of the circadian miRNA (cmiRNA) pair in predicting prognosis and guiding the treatment of LUAD. We first retrieved circadian genes (Cgenes) from the CGDB database, based on which cmiRNAs were predicted using the miRDB and mirDIP databases. The sequencing data of Cgenes and cmiRNAs were retrieved from TCGA and GEO databases. Two random cmiRNAs were matched to a single cmiRNA pair. Finally, univariate Cox proportional hazard analysis, LASSO regression, and multivariate Cox proportional hazard analysis were performed to develop a prognostic signature consisting of seven cmiRNA pairs. The signature exhibited good performance in predicting the overall and progression-free survival. Patients in the high-risk group also showed lower IC50 values for several common chemotherapy and targeted medicines. In addition, we constructed a cmiRNA-Cgenes network and performed a corresponding Gene Ontology and Gene Set enrichment analysis. In conclusion, the novel circadian-related miRNA pair signature could provide a precise prognostic evaluation with the potential capacity to guide individualized treatment regimens for LUAD.

20.
Front Cell Dev Biol ; 10: 818453, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35399527

RESUMO

In recent years, cancer therapies using immune checkpoint inhibitors (ICIs) have achieved meaningful success, with patients with advanced tumors presenting longer survival times and better quality of life. However, several patients still do not exhibit good clinical outcomes for ICI therapy due to low sensitivity. To solve this, researchers have focused on identifying the cellular and molecular mechanisms underlying resistance to ICI therapy. ICI therapy induces apoptosis, which is the most frequent regulated cell death (RCD) but lacks immunogenicity and is regarded as an "immune silent" cell death. Ferroptosis, a unique type of non-apoptotic-RCD, has been preliminarily identified as an immunogenic cell death (ICD), stimulating tumor-antigen-specific immune responses and augmenting anti-tumor immune effects. However, ferroptosis has rarely been used in clinical practice. Present evidence strongly supports that the interferon-γ signaling pathway is at the crossroads of ICI therapy and ferroptosis. TYRO3, a receptor tyrosine kinase, is highly expressed in tumors and can induce anti-programmed cell death (PD)-ligand 1/PD-1 therapy resistance by limiting tumoral ferroptosis. Therefore, in this review, we summarize the clinical practice and effects of ICI therapy in various cancers. We also provide an overview of ferroptosis and report the molecular connections between cancer cell ferroptosis and ICI therapy, and discuss the possibility to reverse ICI therapy resistance by inducing cancer cell ferroptosis.

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