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1.
J Phys Chem B ; 2021 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-33819040

RESUMEN

The protein HIV Reverse Transcriptase (HIV RT) synthesizes a DNA strand according to a template. During the synthesis, the polymerase slides on the double stranded DNA to allow the entry of a new nucleotide to the active site. We use Molecular Dynamics simulations to estimate the free energy profile and the time scale of the DNA-protein's relative displacement in the complex's closed state. We illustrate that the presence of the catalytic magnesium slows down the process. Upon removing the catalytic magnesium ion, the process is rapid and significantly faster than reopening the active site in preparation for the new substrate. We speculate that magnesium regulates DNA translocation. The magnesium locks the DNA into a specific orientation during the chemical addition of the nucleotide. The release of Mg2+ eases DNA sliding and the acceptance of a new substrate.

2.
Artículo en Inglés | MEDLINE | ID: mdl-33825028

RESUMEN

PURPOSE: Visual outcomes after cataract surgery in diabetic patients with retinal or visual pathway disease are difficult to predict as the fundus may be obscured, and assessment of visual potential is challenging. This study assessed the value of visual electrophysiology as a prognostic indicator of visual recovery in diabetic patients with cataract, prior to cataract surgery. METHODS: Forty-one diabetic patients (aged 52-80; 74 eyes) and 13 age-matched non-diabetic control patients (21 eyes) were examined prior to cataract surgery. Pre-surgical examinations included best-corrected visual acuity (BCVA), slit-lamp bio-microscopy, ISCEV-standard full-field electroretinography (ffERG), and flash visual evoked potential (flash VEP) testing. Electrophysiological assessments included quantification of the DA and LA ERG, oscillatory potentials (OPs; OP1, OP2, OP3, OP4) and flash VEP P1, P2, and P3 components. Post-operative BCVA was measured in all cases and the diabetic patients grouped according to the severity of visual acuity loss: mild (logMAR ≤ 0.1), moderate (0.1 < logMAR < 0.5), or severe (logMAR ≥ 0.5). A fourth group included those without diabetes. The pre-surgical electrophysiological data was compared between the four groups by analysis of variance. RESULTS: The severity of post-surgical visual acuity loss in the diabetic patients was classified as mild (N=22 eyes), moderate (N=31 eyes), or severe (N=21 eyes). In the group without diabetes, post-surgical visual impairment was classified as mild (N=21 eyes). The pre-operative DA 10.0 ERG a-wave amplitudes, DA 3.0 ERG OP2 amplitudes, and the LA 3.0 a- and b-wave amplitudes showed best significant differences among the four groups. The flash VEP did not show significant difference between groups. CONCLUSION: Electrophysiological assessment of diabetic patients with cataract can provide a useful measure of retinal function. Full-field ERG components, including the DA 10.0 ERG a-wave, DA 3.0 ERG OP2 component, and the LA 3.0 a- and b-wave amplitudes, are of prognostic value in predicting post-surgical visual acuity, and may inform the surgical management of cataract patients with diabetes.

3.
Eur J Med Chem ; 219: 113419, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33845233

RESUMEN

The pathogenesis of Alzheimer's disease (AD) has been associated with dysregulation of histone deacetylases (HDACs). Previously, acridine-based HDAC inhibitors have shown potential in ameliorating HDAC activity and enhancing neurite outgrowth. In this study, the acridine ring was modified using various phenothiazine derivatives. Several resulting compounds exhibited potent enzyme-inhibiting activity towards class II HDACs when compared to the clinically approved HDAC inhibitor SAHA. Compound 4f demonstrated the highest class II HDAC inhibition (IC50 = 4.6-600 nM), as well as promotion of neurite outgrowth. Importantly, compound 4f displayed no cytotoxicity against neuron cells. Compound 4f was further evaluated for cellular effects. Altogether, these findings show a potential strategy in HDAC inhibition for treatment of the neurological disease.

6.
Artículo en Inglés | MEDLINE | ID: mdl-33837850

RESUMEN

Rb1-inducible coiled-coil 1 (RB1CC1) has been demonstrated to function as an inhibitor of proline-rich/Ca-activated tyrosine kinase 2 (PYK2) by binding to the kinase domain of PYK2, which promotes the proliferation, invasion, and migration of renal cell carcinoma (RCC) cells. Additionally, in breast cancer, PYK2 positively regulates the expression of transcriptional co-activator with PDZ-binding motif (TAZ) which in turn can enhance PDL1 levels in breast and lung cancer cells. The current study was performed to decipher the impact of RB1CC1 in the progression of RCC via regulation of the PYK2/TAZ/PDL1 signaling axis. Expression of RB1CC1 and PYK2 was quantified in clinical tissue samples from RCC patients. The relationship between TAZ and PYK2, TAZ and PDL1 was then validated. The cellular processes of doxorubicin (DOX)-induced human RCC cell lines including the abilities of proliferation, colony formation, sphere formation and apoptosis, as well as the tumorigenicity of transfected cells, were evaluated after the alteration of RB1CC1 expression. RB1CC1 exhibited decreased expression in RCC tissues and was positively correlated with patient survival. RB1CC1 could inhibit the activity of PYK2, which in turn stimulated the stability of TAZ protein by phosphorylating TAZ. Meanwhile, TAZ protein activated PDL1 transcription by binding to the promoter region of PDL1. RB1CC1 overexpression or PYK2 knockdown could help everolimus (EVE) to inhibit tumor proliferation and activate immune response. Taken together, RB1CC1 can potentially augment the response of RCC cells to immunotherapy by suppressing the PYK2/TAZ/PDL1 signaling axis.

7.
Res Vet Sci ; 136: 390-395, 2021 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-33799169

RESUMEN

Forsythiaside A, a major bioactive component extracted from Forsythiae fructus, possesses multiple biological properties, especially anti-inflammatory properties. In the present study, the anti-inflammatory effect of forsythiaside A was investigated in lipopolysaccharide (LPS)-induced acute mastitis in mice. Our results showed that the expression levels of IL-1ß, IL-6, TNF-α, p38 MAPK, IκBα, and NF-κB p65 in the LPS group were all up-regulated, and obvious pathological changes were observed by sectioning. Compared with those in the LPS group, the expression levels of the above factors were significantly reduced, and the inflammation symptoms were also significantly reduced by section observation after forsythiaside A intervention. These results indicated that forsythiaside A effectively inhibited LPS-induced mammary inflammation in mice by attenuating the activation of the NF-κB and p38 MAPK signaling pathways.

8.
Neuroimage Clin ; 30: 102613, 2021 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-33823388

RESUMEN

OBJECTIVE: We aimed to identify differences in network properties of white matter microstructure between asymptomatic ulcerative colitis (UC) participants who had a history of chronic gut inflammation, healthy controls (HCs) and a disease control group without gut inflammation (irritable bowel syndrome; IBS). DESIGN: Diffusion weighted imaging was conducted in age and sex-matched participants with UC, IBS, and HCs (N = 74 each), together with measures of gastrointestinal and psychological symptom severity. Using streamline connectivity matrices and graph theory, we aimed to quantify group differences in brain network connectivity. Regions showing group connectivity differences were correlated with measures showing group behavioral and clinical differences. RESULTS: UC participants exhibited greater centrality in regions of the somatosensory network and default mode network, but lower centrality in the posterior insula and globus pallidus compared to HCs (q < 0.05). Hub analyses revealed compromised hubness of the pallidus in UC and IBS compared to HCs which was replaced by increased hubness of the postcentral sulcus. Surprisingly, few differences in network matrices between UC and IBS were identified. In UC, centrality measures in the secondary somatosensory cortex were associated with depression (q < 0.03), symptom related anxiety (q < 0.04), trait anxiety (q < 0.03), and symptom duration (q < 0.05). CONCLUSION: A history of UC is associated with neuroplastic changes in several brain networks, which are associated with symptoms of depression, trait and symptom-related anxiety, as well as symptom duration. When viewed together with the results from IBS subjects, these findings suggest that chronic gut inflammation as well as abdominal pain have a lasting impact on brain network organization, which may play a role in symptoms reported by UC patients, even when gut inflammation has subsided.

9.
J Environ Manage ; 289: 112493, 2021 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-33823409

RESUMEN

In this study, samples of daily foods, drinking waters, surface waters, and soils were collected and screened to investigate the external exposure of Sb and As from various intake pathways in typical Sb mining area. Biomarker samples of residents were analyzed to monitor internal exposure characteristic of Sb and As in human body. Exposure dosages of As and Sb and transfer of Sb and As from environment to human body were estimated based on the external and internal exposure. The following results were obtained: daily intakes of food accounted for major intakes of both Sb and As, and highlighted the significance of foods intakes from rice and vegetable. The results of Monte Carlo simulations showed that total daily intake of Sb(n = 1444)and As(n = 1131) approximately reached 1.08 × 10-2 mg/kg/d and 1.19 × 10-3 mg/kg/d, in which 98.82% and 63.07% of residents have exceeded the threshold dosages of Sb and As. The contaminants contents in biomarkers indicated that Sb exhibited the similar internal exposure as As, while the total transfer rate of Sb from environment to human were estimated as approximately 2.04-2.40 times lower than As. This study also suggested that drinking water is another important pathway with high bioavailability and male resident may present higher priority than female in uptake of Sb and As. The paper suggested the similarity and difference on bioavailability existed in Sb and its group V elements, As, that would provide the essential information on exposure of Sb and As in the typical Sb mine area.

10.
Global Health ; 17(1): 40, 2021 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-33823875

RESUMEN

BACKGROUND: Little is known about the prevalence of and risk factors for adolescent mental health problems during the COVID-19 outbreak. We aimed to investigate the prevalence of depressive symptoms, their association with study-relevant problems, and the moderating effect of parent-child relationship among Chinese adolescents during the school closures. METHODS: We performed a cross-sectional analysis with data collected in middle and high schools in Taizhou, China. Students completed an online survey between April 16 and May 14, 2020. Depressive symptoms were assessed using the Children's Depression Inventory. Three types of study problems were recorded, including having difficulty in studying at home, dislike of remote learning, and excessive screen entertainment time. Parental relationships were categorized into good or normal relationship and poor relationship. Linear regression and logistic regression analyses were conducted to investigate the associations between study-relevant problems and depressive symptoms. RESULTS: Using data from 6435 adolescents, we found that the prevalence of depressive symptoms was 17.7%. All the study problem measures were associated with more severe depressive symptoms. There was a moderating effect of the parental relationship on the associations between study problems and depressive symptoms. The association between number of study problems and depressive symptoms was stronger in adolescents with a poor parent-child relationship (regression coefficient 4.34 [95% CI 2.97, 5.72]) than those with a good or normal relationship (2.55 [2.35, 2.75]), p for interaction 0.002, on multivariable adjustment. CONCLUSIONS: Study problems due to school closures were particularly problematic for adolescents who had poor parent-child relationships. Public health initiatives could help students to adjust study habits and improve parent-child relationships, thereby protecting against the development of depression.

11.
J Int Med Res ; 49(4): 300060521999534, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33827306

RESUMEN

OBJECTIVE: α2­agonists and opioids have been used as intrathecal adjuvants to local anesthetics for several years, but the effect of intrathecal dexmedetomidine (Dex) or sufentanil combined with epidural ropivacaine in labor analgesia is not fully understood. METHODS: A total of 108 parturient women receiving combined spinal-epidural labor analgesia were randomly divided into three groups. Group C received l mL saline (0.9%) intrathecally, Group D received 5 µg Dex intrathecally, and Group S received 5 µg sufentanil intrathecally. All parturient women then received 0.1% epidural ropivacaine and 0.2 µg/mL sufentanil for patient-controlled epidural analgesia with standard settings. The visual analog scale score, onset time, duration of intrathecal injection, local anesthetic requirements, and side effects were recorded. RESULTS: The labor analgesia effects in Groups D and S were better than those in Group C. Groups D and S displayed significantly shorter onset times, longer durations of intrathecal injection, and reduced local anesthetic requirements compared with Group C. The incidence of shivering and pruritus in Group D was lower than that in Group S. CONCLUSION: Intrathecal administration of 5 µg Dex could improve epidural labor analgesia effects.This randomized controlled clinical trial was registered with the Chinese Clinical Registry Center (ChiCTR-1800014943, http://www.chictr.org.cn/).

12.
Zhongguo Yi Liao Qi Xie Za Zhi ; 45(2): 194-199, 2021 Apr 08.
Artículo en Chino | MEDLINE | ID: mdl-33825381

RESUMEN

OBJECTIVE: To understand the current situation of artificial intelligence production enterprise quality management system, so as to provide reference basis for the research and standardization of Artificial Intelligence Medical Device (AIMD) product quality management. METHODS: Based on YY/T 0287-2017 Medical Device Quality Management System for Regulatory Requirements, Medical Equipment Production and the Quality Control Standard for Independent Software Appendix and Xavier GMLP report, the relevant factors were screened and the questionnaire was designed by combining expert consultation and literature review. Then, a total of 32 representative AIMD enterprises were invited to fill in the questionnaire. Descriptive statistical analysis was performed on the data results using Excel 2016. RESULTS: Through in-depth analysis of the four themes in product planning and design, result output, product quality control and product change, it was found that it was necessary for enterprises participating in the survey to improve the quality management system of AIMD products to different degrees. CONCLUSIONS: This study is the first time to systematically investigate the status quo of quality management of AIMD enterprises. The result will be useful for the establishment and continuous improvement of product quality management system. It will also provide a reference for the research of AIMD product quality management and the establishment of the standard.


Asunto(s)
Inteligencia Artificial , Programas Informáticos , Control de Calidad , Estándares de Referencia
13.
Ann Palliat Med ; 2021 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-33832322

RESUMEN

The liver is one of the most common sites of metastatic spread of lung cancer, and the process of metastasis is regulated by many factors. A number of genes, including multiple tumor suppressor 1 (mts1), p120 catenin, and CT45A1, increase the possibility of hepatic metastasis in lung cancer, whereas Tip30/ CC3, CUL5, and SOCS3 expression in lung tumors inhibit tumor metastasis. microRNAs (miRNAs), such as miRNA-126, miRNA-338, and miRNA-218, can affect the metastasis of lung cancer cells to the liver. The D114-Notch signaling pathway can inhibit liver metastasis in small cell lung cancer. Serum tumor markers cytokeratin 19 fragment antigen 21-1 and neuron-specific enolase (NSE) are closely related to the risk of hepatic metastasis in lung cancer. Based on previously published literature, we found that the metastasis and invasion of lung cancer to the liver are determined by molecular factors. Therefore, the selective identification and intervention of these erroneous signals can predict early lung cancer metastasis to the liver. In this review article, we describe the mechanisms and influencing factors (genes, signal pathways, chemicals, proteins, miRNAs) of hepatic metastasis in lung cancer. We hope to provide a summary of the evidence for the mechanisms by which related genes or proteins affect the malignancy of liver metastasis from lung cancer so that doctors and researchers can improve treatment options.

14.
Brief Bioinform ; 2021 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-33834194

RESUMEN

Transcriptional regulation is associated with complicated mechanisms including multiple molecular interactions and collaborative drive. Long noncoding RNAs (lncRNAs) have highly structured characteristics and play vital roles in the regulation of transcription in organisms. However, the specific contributions of conformation feature and underlying molecular mechanisms are still unclear. In the present paper, a hypothesis regarding molecular structure effect is presented, which proposes that lncRNAs fold into a complex spatial architecture and act as a skeleton to recruit transcription factors (TF) targeted binding, and which is involved in cooperative regulation. A candidate set of TF-lncRNA coregulation was constructed, and it was found that structural accessibility affected molecular binding force. In addition, transcription factor binding site (TFBS) regions of myopia-related lncRNA transcripts were disturbed, and it was discovered that base mutations affected the occurrence of significant molecular allosteric changes in important elements and variable splicing regions, mediating the onset and development of myopia. The results originated from structureomics and interactionomics and created conditions for systematic research on the mechanisms of structure-mediated TF-lncRNA coregulation in transcriptional regulation. Finally, these findings will help further the understanding of key regulatory roles of molecular allostery in cell physiological and pathological processes.

15.
Neuroimage ; 235: 118018, 2021 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-33794358

RESUMEN

Morphological brain networks, in particular those at the individual level, have become an important approach for studying the human brain connectome; however, relevant methodology is far from being well-established in their formation, description and reproducibility. Here, we extended our previous study by constructing and characterizing single-subject morphological similarity networks from brain volume to surface space and systematically evaluated their reproducibility with respect to effects of different choices of morphological index, brain parcellation atlas and similarity measure, sample size-varying stability and test-retest reliability. Using the Human Connectome Project dataset, we found that surface-based single-subject morphological similarity networks shared common small-world organization, high parallel efficiency, modular architecture and bilaterally distributed hubs regardless of different analytical strategies. Nevertheless, quantitative values of all interregional similarities, global network measures and nodal centralities were significantly affected by choices of morphological index, brain parcellation atlas and similarity measure. Moreover, the morphological similarity networks varied along with the number of participants and approached stability until the sample size exceeded ~70. Using an independent test-retest dataset, we found fair to good, even excellent, reliability for most interregional similarities and network measures, which were also modulated by different analytical strategies, in particular choices of morphological index. Specifically, fractal dimension and sulcal depth outperformed gyrification index and cortical thickness, higher-resolution atlases outperformed lower-resolution atlases, and Jensen-Shannon divergence-based similarity outperformed Kullback-Leibler divergence-based similarity. Altogether, our findings propose surface-based single-subject morphological similarity networks as a reliable method to characterize the human brain connectome and provide methodological recommendations and guidance for future research.

16.
Nano Lett ; 2021 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-33848169

RESUMEN

The pyrolysis of metal-organic frameworks (MOFs) is an ingenious way to synthesize carbon-based materials with unique morphology for various applications including electrocatalysis. In this work, we reported a facile morphology regulation strategy for the synthesis of a spherical superstructure of MOF nanosheets. The use of metal hydroxide nanosheets on Zn particles as precursors/templates allowed MOFs with general polyhedron shape to form nanosheets and assemble into a spherical superstructure in the ligand solution. Further, a hollow spherical superstructure of carbon nanosheets decorated with metal-based nanoparticles was fabricated through the pyrolysis of MOF nanosheet superstructures at 950 °C, where the substrate/template Zn particle cores were evaporated away. The obtained composites possess carbon-based superstructures with abundant mesopores and metal-based nanoparticles with rich alloy/oxide interfaces. These features endow this MOF-derived carbon-based material with outstanding bifunctional activity for oxygen reduction/evolution reactions and great performances in Zn-air batteries.

17.
Psychogeriatrics ; 2021 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-33851473

RESUMEN

Phospholipid transfer protein (PLTP) is a complex glycosylated protein that mediates the transfer of phospholipids, unesterified cholesterol, diacylglycerides, specific apolipoproteins, and tocopherols between different classes of lipoproteins as well as between lipoproteins and cells. Many studies have associated PLTP with a variety of lipid metabolic diseases. However, recent studies have indicated that PLTP is highly expressed in the brain of vertebrate and may be related to many central nervous system diseases, such as Alzheimer's disease. Here, we review the data and report the role and mechanisms PLTP in Alzheimer's disease.

18.
Sensors (Basel) ; 21(6)2021 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-33802190

RESUMEN

In laser systems, beam pointing usually drifts as a consequence of various disturbances, e.g., inherent drift, airflow, transmission medium variation, mechanical vibration, and elastic deformation. In this paper, we develop a laser beam pointing control system with Fast Steering Mirrors (FSMs) and Position Sensitive Devices (PSDs), which is capable of stabilizing both the position and angle of a laser beam. Specifically, using the ABCD matrix, we analyze the kinematic model governing the relationship between the rotation angles of two FSMs and the four degree-of-freedom (DOF) beam vector. Then, we design a Jacobian matrix feedback controller, which can be conveniently calibrated. Since disturbances vary significantly in terms of inconsistent physical characteristics and temporal patterns, great challenges are imposed to control strategies. In order to improve beam pointing control performance under a variety of disturbances, we propose a data-driven disturbance classification method by using a Recurrent Neural Network (RNN). The trained RNN model can classify the disturbance type in real time, and the corresponding type can be subsequently used to select suitable control parameters. This approach can realize the universality of the beam stabilization pointing system under various disturbances. Experiments on beam pointing control under several typical external disturbances are carried out to verify the effectiveness of the proposed control system.

19.
Behav Brain Res ; 406: 113233, 2021 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-33737088

RESUMEN

Despite findings showing that acute exercise may help enhance emotion regulation, the neurophysiological mechanisms of these effects remain poorly understood. In this study, we examined whether acute exercise influences cognitive emotion regulation, and, in particular, an implicit cognitive reappraisal. Twenty sedentary young women were randomly assigned to either a control group (n = 10) or an exercise group (n = 10). Participants underwent an implicit cognitive reappraisal task twice, before and after the 30-min acute exercise or control, alongside functional near-infrared spectroscopy recordings (NIRS). The left dorsolateral prefrontal cortex (dlPFC) and left orbital frontal cortex (OFC) were activated during implicit cognitive reappraisal at baseline, but only the left dlPFC activation was linked with behavioral performance. Acute exercise enhanced the activation of these regions, reflective of the partial neural bases of implicit cognitive reappraisal, in the left dlPFC and left OFC, but did not alter the behavioral performance. Results also showed that acute exercise moderated the positive effect of left dlPFC activation on implicit cognitive reappraisal performance; specifically, this effect was stronger in the exercise group. In conclusion, the enhanced activation of the left dlPFC by acute exercise and the increased link between behavioral performance and its neural indices may point to acute exercise as a promoter of implicit cognitive reappraisal.

20.
Br J Ophthalmol ; 2021 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-33785508

RESUMEN

AIM: To explore and evaluate an appropriate deep learning system (DLS) for the detection of 12 major fundus diseases using colour fundus photography. METHODS: Diagnostic performance of a DLS was tested on the detection of normal fundus and 12 major fundus diseases including referable diabetic retinopathy, pathologic myopic retinal degeneration, retinal vein occlusion, retinitis pigmentosa, retinal detachment, wet and dry age-related macular degeneration, epiretinal membrane, macula hole, possible glaucomatous optic neuropathy, papilledema and optic nerve atrophy. The DLS was developed with 56 738 images and tested with 8176 images from one internal test set and two external test sets. The comparison with human doctors was also conducted. RESULTS: The area under the receiver operating characteristic curves of the DLS on the internal test set and the two external test sets were 0.950 (95% CI 0.942 to 0.957) to 0.996 (95% CI 0.994 to 0.998), 0.931 (95% CI 0.923 to 0.939) to 1.000 (95% CI 0.999 to 1.000) and 0.934 (95% CI 0.929 to 0.938) to 1.000 (95% CI 0.999 to 1.000), with sensitivities of 80.4% (95% CI 79.1% to 81.6%) to 97.3% (95% CI 96.7% to 97.8%), 64.6% (95% CI 63.0% to 66.1%) to 100% (95% CI 100% to 100%) and 68.0% (95% CI 67.1% to 68.9%) to 100% (95% CI 100% to 100%), respectively, and specificities of 89.7% (95% CI 88.8% to 90.7%) to 98.1% (95%CI 97.7% to 98.6%), 78.7% (95% CI 77.4% to 80.0%) to 99.6% (95% CI 99.4% to 99.8%) and 88.1% (95% CI 87.4% to 88.7%) to 98.7% (95% CI 98.5% to 99.0%), respectively. When compared with human doctors, the DLS obtained a higher diagnostic sensitivity but lower specificity. CONCLUSION: The proposed DLS is effective in diagnosing normal fundus and 12 major fundus diseases, and thus has much potential for fundus diseases screening in the real world.

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