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1.
ACS Appl Mater Interfaces ; 16(9): 11880-11889, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38408367

RESUMO

Mixing fillers featured with wide band gaps in polymers can effectively meet the requirement of higher energy storage densities. However, the fundamental relationship between the crystal structures of fillers and the dielectric properties of the corresponding nanocomposites is still unclear. Accordingly, we introduced ultralow contents of the synthesized cubic Hafnium dioxide (c-HfO2) or monoclinic Hafnium dioxide (m-HfO2) as deep traps into poly(ether imide) (PEI) to explore their effects on dielectric properties and the charge-blocking mechanism. m-HfO2/PEI showed better charge trapping due to the higher electron affinity and deeper trap energy. At room temperature, the 0.4 vol % m-HfO2/PEI maintains an ultralow dielectric loss of 0.008 while obtaining a dielectric constant twice that of pure PEI at 1 kHz, simultaneously outperforming in terms of leakage current density, breakdown strength (452 kV mm-1), discharge energy density (Ud, 5.03 J cm-3), charge-discharge efficiency (η, 92%), and dielectric thermal stability. At 125 °C, it exhibits a considerable Ud of 2.48 J cm-3 and a high η of 85% at 300 kV mm-1, surpassing the properties of pure PEI. This promising work opens up a new path for studying HfO2-derived dielectrics with unique crystal structures.

2.
Mater Horiz ; 11(1): 271-282, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-37938919

RESUMO

The all-organic high-temperature polymer dielectrics with promising scale-up potential have witnessed much progress in the energy storage area, etc. However, the electron suppression trap mechanisms behind many all-organic dielectrics are still unclear, especially for high temperature resistant poly(p-phenylene benzobisoxazole) (PBO) polymers. To resolve this tough issue, we herein innovatively prepared PBO-based all-organic thin films containing sulfone-based polyimide (P(DSDA-ODA)) functioning as an electron trap phase using a facile and scalable co-curing method. The great linear dielectric properties of the prepared P(DSDA-ODA)/PBO films hold high dielectric thermal stability over the temperature range from 25 °C to 200 °C. The 60 wt% P(DSDA-ODA) systems yield the lowest leakage current (3.8 × 10-8 A cm-2). The tight structure and reduced leakage current enable an enhanced breakdown strength of 60 wt% P(DSDA-ODA)/PBO (470 kV mm-1), which is 1.7 times that of pure PBO. Meanwhile, it can reach 4.16 J cm-3 of energy density, which is 257% higher than that for pure PBO thin films while concurrently maintaining a long stable charge-discharge cycle (at least 5000 times) and high charge-discharge efficiency at 85.10%. Moreover, P(DSDA-ODA)/PBO still exhibits excellent energy storage performance at high temperature compared to PBO. This innovative strategy is further verified by replacing P(DSDA-ODA) with P(6FDA-ODA), and therefore lays a solid foundation for more investigation on scalable all-organic dielectrics.

3.
Small ; 20(2): e2305277, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37661569

RESUMO

How to better understand the influence of electromagnetic parameters on the absorbing properties of electromagnetic wave absorbers (EMAs) is an essential prerequisite for further synthesis and development of high-performance EMAs. In this work, an improved wave cancellation theory is used as a guiding principle to prepare N-doped carbon-coated cobalt nanoparticles (Co@NC) using ZIF-8@ZIF-67 as the precursor, thus enabling controllable electromagnetic parameters by regulating the conduction loss and dipole polarization ability. The Co@NC generated by pyrolysis at 700 °C under H2 atmosphere presents an optimized absorption performance. Benefiting from developed wave cancellation theory, the thickness of the film can be accurately adjusted so that the difference between the amplitude of the reflected and transmitted electromagnetic waves is only 0.001 and the phase difference is 180.05°, thus achieving a minimum reflection loss (RLmin (dB)) of -64.0 dB. Meanwhile, a maximum effective absorption bandwidth of 5.4 GHz is achieved simultaneously attributing to its most suitable electromagnetic parameters. Accordingly, the current research based on wave cancellation theory significantly contributes to understand the relationships between electromagnetic parameters and wave absorption properties, therefore providing a theoretical insight into the further development of high-performance EMAs.

4.
Angew Chem Int Ed Engl ; 62(51): e202315143, 2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-37964724

RESUMO

With the rapid development of integrated circuits towards miniaturization and complexity, there is an urgent need for materials with low dielectric constant/loss and high processing temperatures to effectively prevent signal delay and crosstalk. With high porosity, thermal stability, and easy structural modulation, covalent organic frameworks have great potential in the field of low dielectric materials. However, the optimization of dielectric properties by modulating the conjugated/plane curvature structure of covalent organic frameworks (COFs) has rarely been reported. Accordingly, we herein innovatively prepare COF films with adjustable planar curvature, hence possessing ultralow dielectric constant (1.9 at 1 kHz), ultralow dielectric loss at 1 kHz (0.0029 at room temperature, 0.0052 at 200 °C), high thermal decomposition temperature (5 % weight loss temperature, 473 °C) and good hydrophobicity (water contact angle, 105.3°). Also, to the best of our knowledge, we are the first to report that the resulting COF film enables high surface potential (≈320 V) for one week, attributing to its intrinsic high porosity, thus presenting great potential in electret applications. Accordingly, this innovative work provides a readily available and scalable idea to prepare materials with comprehensively excellent dielectric and electret properties as well as high processing temperatures simultaneously for advanced electronic device applications.

5.
Small ; 19(49): e2305353, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37606896

RESUMO

The combination of 2D magnetic nanosheets and mesoporous carbon with unique interfaces shows considerable prospects for microwave absorption (MA). However, traditional assembly procedures make it impossible to accurately manage the assembly of magnetic nanosheets in carbon matrices. Herein, a reverse strategy for preparing complex magnetic nanosheet cores inside carbon-based yolk-shell structures is developed. This innovative approach focuses on controlling the initial crystallite formation sites in a hydrothermal reaction as well as the inflow and in situ growth behavior of 2D NiCo-layered double hydroxide precursors based on the capillary force induced by hollow mesoporous carbon nanospheres. Accordingly, the as-prepared YS-CNC-2 absorber exhibits remarkable MA performances, with an optimal reflection loss as low as -60.30 dB at 2.5 mm and an effective absorption bandwidth of 5.20 GHz at 2.0 mm. The loss of electromagnetic waves (EMW) depends on natural resonance loss, dipole polarization relaxation, and multiple scattering behavior. On top of that, the functionalized super-hydrophobic MA coating is produced in spraying and curing processes utilizing YS-CNC-2 nanoparticles and fumed silica additives in the polydimethylsiloxane matrix. The excellent thermal insulation, self-cleaning capability, and durability in diverse solutions of the coating promise potential applications for military equipment in moist situations.

6.
Polymers (Basel) ; 15(14)2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37514477

RESUMO

The development of pulse power systems and electric power transmission systems urgently require the innovation of dielectric materials possessing high-temperature durability, high energy storage density, and efficient charge-discharge performance. This study introduces a core-double-shell-structured iron(II,III) oxide@barium titanate@silicon dioxide/polyetherimide (Fe3O4@BaTiO3@SiO2/PEI) nanocomposite, where the highly conductive Fe3O4 core provides the foundation for the formation of microcapacitor structures within the material. The inclusion of the ferroelectric ceramic BaTiO3 shell enhances the composite's polarization and interfacial polarization strength while impeding free charge transfer. The outer insulating SiO2 shell contributes excellent interface compatibility and charge isolation effects. With a filler content of 9 wt%, the Fe3O4@BaTiO3@SiO2/PEI nanocomposite achieves a dielectric constant of 10.6, a dielectric loss of 0.017, a high energy density of 5.82 J cm-3, and a charge-discharge efficiency (η) of 72%. The innovative aspect of this research is the design of nanoparticles with a core-double-shell structure and their PEI-based nanocomposites, effectively enhancing the dielectric and energy storage performance. This study provides new insights and experimental evidence for the design and development of high-performance dielectric materials, offering significant implications for the fields of electronic devices and energy storage.

7.
Clinics (Sao Paulo) ; 78: 100232, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37364352

RESUMO

BACKGROUND: This study aimed to evaluate the association between Monocyte Lymphocyte Ratio (MLR) and Abdominal Aortic Calcification (AAC) in adults over 40 years of age in the United States. METHODS: Data were collected from the 2013-2014 National Health and Nutrition Examination Survey (NHANES). AAC was quantified by the Kauppila score system based on dual-energy X-Ray absorptiometry. Severe AAC was defined as a total AAC score > 6. The lymphocyte count and monocyte count can be directly obtained from laboratory data files. Multivariable logistic regression models were used to determine the association between MLR and the AAC score and severe AAC. RESULTS: A total of 3,045 participants were included in the present study. After adjusting for multiple covariates, MLR was positively associated with higher AAC score (ß = 0.21, 95% CI 0.07, 0.34, p = 0.0032) and the odds of severe AAC increased by 14% per 0.1 unit increase in the MLR (OR = 1.14, 95% CI 1.00, 1.31, p = 0.0541). The Odds Ratio (OR) (95% CI) of severe AAC for participants in MLR tertile 3 was 1.88 (1.02, 3.47) compared with those in tertile 1 (p for trend = 0.0341). Subgroup analyses showed that a stronger association was detected in the elderly compared with non-elderly (p for interaction = 0.0346) and diabetes compared with non-diabetes (borderline significant p for interaction = 0.0578). CONCLUSION: In adults in the United States, MLR was associated with higher AAC scores and a higher probability of severe AAC. MLR may become a promising tool to predict the risk of AAC.


Assuntos
Doenças da Aorta , Calcificação Vascular , Humanos , Adulto , Estados Unidos/epidemiologia , Pessoa de Meia-Idade , Inquéritos Nutricionais , Estudos Transversais , Monócitos , Calcificação Vascular/diagnóstico por imagem , Linfócitos , Aorta Abdominal/diagnóstico por imagem , Fatores de Risco , Doenças da Aorta/diagnóstico por imagem
8.
Small ; 19(40): e2302961, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37264718

RESUMO

Constructing the adjustable surface conductive networks is an innovation that can achieve a balance between enhanced attenuation and impedance mismatch according to the microwave absorption mechanism. However, the traditional design strategies remain significant challenges in terms of rational selection and controlled growth of conductive components. Herein, a hierarchical construction strategy and quantitative construction technique are employed to introduce conductive metal-organic frameworks (MOFs) derivatives in the classic yolk-shell structure composed of electromagnetic components and the cavity for remarkable optimized performance. Specifically, the surface conductive networks obtained by carbonized ZIF-67 quantitative construction, together with the Fe3 O4 magnetic core and dielectric carbon layer linked by the cavity, achieve the cooperative enhancement of impedance matching optimization and synergistic attenuation in the Fe3 O4 @C@Co/N-Doped C (FCCNC) absorber. This interesting design is further verified by experimental results and simulation calculations. The products FCCNC-2 yield a distinguished minimum reflection loss of -66.39 dB and an exceptional effective absorption bandwidth of 6.49 GHz, indicating that moderate conduction excited via hierarchical and quantitative design can maximize the absorption capability. Furthermore, the proposed versatile methodology of surface assembly paves a new avenue to maximize beneficial conduction effect and manipulate microwave attenuation in MOFs derivatives.

9.
ACS Appl Mater Interfaces ; 15(19): 23792-23803, 2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37130243

RESUMO

Polyimide (PI) and its derivative polyetherimide (PEI) have been widely investigated as promising candidates for dielectric energy storage due to their excellent intrinsic features. However, most of the current research for PI- or PEI-based dielectric nanocomposites only focuses on a certain polar group contained in a dianhydride monomer, while there are very few studies on exploring the effect of a series of polar groups derived from various dianhydride monomers on the dielectric properties of nanocomposites. To fill this gap, we herein fabricated and investigated a series of novel hyperbranched polyimides grafted on barium titanate nanoparticles (HBPI@BT) using different dianhydride monomers and their nanocomposites with the PEI matrix. The results showed that sophisticated hyperbranched structures effectively alleviated the incompatibility between fillers and the matrix, thus significantly improving the bonding energy of nanocomposites, especially for HBPI-S@BT/PEI (797.7 kJ/mol). The Ud of HBPI-S@BT/PEI reached 8.38 J/cm3, which is 3.3 times higher than that of pure PEI. The HBPI-F@BT/PEI nanocomposites achieved high breakdown strength (∼500 MV/m) and low dielectric loss (0.008) simultaneously. The dielectric constants of HBPI@BT/PEI nanocomposites remained at a stable level from 25 to 150 °C. This work provides us promising hyperbranched structured materials for potentially advanced dielectric applications such as field effect transistors.

10.
Small ; 19(1): e2204649, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36354192

RESUMO

The construction of ordered hierarchical porous structures in metal-organic frameworks (MOFs) and their derivatives is highly promising to meet the low-density and high-performance demands of microwave absorption materials. However, traditional methods based on sacrificial templates or corrosive agents inevitably suffer from the collapse of the microporous framework and the accumulation of nanoparticles during the carbonization transformation, resulting in the deteriorating impedance match, which greatly limits the incident and attenuation of microwaves. Herein, an induced crystallization and controllable nanoarchitectonics strategy is employed to replace traditional growing-etching methods and successfully synthesize carbonized 3D-ordered macroporous Co@N-doped carbon (3DOM Co@NDC) based on the 3D-ordered template. The obtained 3D-ordered macroporous structure ensures the stable growth of hybrid carbon frameworks and CoC nanoparticles without collapse, preserves abundant interfaces for both the incident and attenuation performance, so as to significantly improve the impedance matching and absorption properties compared to conventional MOFs derivatives. The minimum reflection loss of 3DOM Co@NDC is -57.36 dB at the thickness of 1.9 mm, and the effective bandwidth is 7.36 GHz at 1.6 mm. Moreover, the innovative strategy to prepare 3D-ordered hierarchical macroporous structures opens up a new avenue for advanced MOFs-derived absorbers with excellent performance.

11.
Clinics ; 78: 100232, 2023. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1506011

RESUMO

Abstract Background This study aimed to evaluate the association between Monocyte Lymphocyte Ratio (MLR) and Abdominal Aortic Calcification (AAC) in adults over 40 years of age in the United States. Methods Data were collected from the 2013-2014 National Health and Nutrition Examination Survey (NHANES). AAC was quantified by the Kauppila score system based on dual-energy X-Ray absorptiometry. Severe AAC was defined as a total AAC score > 6. The lymphocyte count and monocyte count can be directly obtained from laboratory data files. Multivariable logistic regression models were used to determine the association between MLR and the AAC score and severe AAC. Results A total of 3,045 participants were included in the present study. After adjusting for multiple covariates, MLR was positively associated with higher AAC score (β = 0.21, 95% CI 0.07, 0.34, p = 0.0032) and the odds of severe AAC increased by 14% per 0.1 unit increase in the MLR (OR = 1.14, 95% CI 1.00, 1.31, p = 0.0541). The Odds Ratio (OR) (95% CI) of severe AAC for participants in MLR tertile 3 was 1.88 (1.02, 3.47) compared with those in tertile 1 (p for trend = 0.0341). Subgroup analyses showed that a stronger association was detected in the elderly compared with non-elderly (p for interaction = 0.0346) and diabetes compared with non-diabetes (borderline significant p for interaction = 0.0578). Conclusion In adults in the United States, MLR was associated with higher AAC scores and a higher probability of severe AAC. MLR may become a promising tool to predict the risk of AAC.

12.
J Med Virol ; 93(7): 4265-4272, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33463721

RESUMO

Several descriptive studies have reported that higher neutrophil count (NC) may be correlated with poor prognosis in patients with confirmed COVID-19 infection. However, the findings from these studies are limited by methodology and data analysis. This study is a cohort study. We nonselectively and consecutively collected a total of 663 participants in a Chinese hospital from January 7 to February 28. Standardized and two-piecewise Cox regression model were employed to evaluate the association between baseline neutrophil count (bNC), neutrophil count change rate (NCR), and death. bNC had a U-shaped association with death. In the range of 0.1 to ≤1.49 × 109 /L (hazard ratio [HR] = 0.19, 95% confidence interval [CI] = 0.05-0.66) and >3.55 × 109 /L of bNC (HR = 2.82, 95% CI = 1.19-6.67), the trends on bNC with mortality were opposite. By recursive algorithm, the bNC at which the risk of the death was lower in the range of >1.49 to ≤3.55 × 109 /L (HR = 13.64, 95% CI = 0.25-74.71). In addition, we find that NCRs (NCR1 and NCR2) are not associated with COVID-19-related deaths. Compared with NCR, bNC has the potential to be used for early risk stratification in patients with COVID-19 infection. The relationship between bNC and mortality was U-shaped. The safe range of bNC was 1.64-4.0 × 109 /L. Identifying the correlation may be helpful for early risk stratification and medical decision-making.


Assuntos
COVID-19/imunologia , COVID-19/mortalidade , Neutrófilos/imunologia , SARS-CoV-2/imunologia , China , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Risco , Fatores de Risco
13.
J Gerontol A Biol Sci Med Sci ; 76(3): 456-462, 2021 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-32766817

RESUMO

BACKGROUND: The epidemic of COVID-19 presents a special threat to older adults. However, information on kidney damage in older patients with COVID-19 is limited. Acute kidney injury (AKI) is common in hospitalized adults and associated with poor prognosis. We sought to explore the association between AKI and mortality in older patients with COVID-19. METHODS: We conducted a retrospective, observational cohort study in a large tertiary care university hospital in Wuhan, China. All consecutive inpatients older than 65 years with COVID-19 were enrolled in this cohort. Demographic data, laboratory values, comorbidities, treatments, and clinical outcomes were all collected. Data were compared between patients with AKI and without AKI. The association between AKI and mortality was analyzed. RESULTS: Of 1764 in-hospital patients, 882 older adult cases were included in this cohort. The median age was 71 years (interquartile range: 68-77), 440 (49.9%) were men. The most presented comorbidity was cardiovascular diseases (58.2%), followed by diabetes (31.4%). Of 882 older patients, 115 (13%) developed AKI and 128 (14.5%) died. Patients with AKI had higher mortality than those without AKI (68 [59.1%] vs 60 [7.8%]; p < .001). Multivariable Cox regression analysis showed that increasing odds of in-hospital mortality are associated with higher interleukin-6 on admission, myocardial injury, and AKI. CONCLUSIONS: Acute kidney injury is not an uncommon complication in older patients with COVID-19 but is associated with a high risk of death. Physicians should be aware of the risk of AKI in older patients with COVID-19.


Assuntos
Injúria Renal Aguda/mortalidade , COVID-19/mortalidade , Mortalidade Hospitalar , Pneumonia Viral/mortalidade , Idoso , Idoso de 80 Anos ou mais , COVID-19/epidemiologia , China/epidemiologia , Feminino , Hospitalização , Humanos , Masculino , Pandemias , Pneumonia Viral/virologia , Prognóstico , Estudos Retrospectivos , SARS-CoV-2
14.
Nutrition ; 78: 110930, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32854020

RESUMO

OBJECTIVES: High-risk patients ≥65 y of age with coronavirus disease 2019 (COVID-19) tended to have lower serum prealbumin concentrations. The aim of this study was to investigate the association of prealbumin at baseline on COVID-19-related mortality in elderly patients (≥65 y of age). METHODS: We non-selectively and consecutively collected participants from Tongji Hospital in Wuhan from January 17 to February 17, 2020. Univariate and multivariate logistic regression models were employed to evaluate the correlation between prealbumin and in-hospital outcomes (in-hospital mortality, admission to the intensive care unit [ICU], and mechanical ventilation) in elderly patients with COVID-19. Linear trend was performed by entering the median value of each category of prealbumin tertile as a continuous variable and was visually confirmed by using generalized additive models. Interaction and stratified analyses were conducted as well. RESULTS: We included 446 elderly patients with COVID-19 in the final analyses. In-hospital mortality was 14.79%. Of the 446 patients, 15.47% were admitted to the ICU and 21.3% required mechanical ventilation. Compared with patients in the highest tertile, the prealbumin of patients in the lowest tertile had a 19.09-fold higher risk for death [odds ratio (OR), 20.09; 95% confidence interval (CI), 3.62-111.64; P = 0.0006], 25.39-fold higher risk for ICU admission (OR, 26.39; 95% CI, 4.04-172.39; P = 0.0006), and 1.8-fold higher risk for mechanical ventilation (OR, 2.8; 95% CI, 1.15-6.78; P = 0.0227) after adjustment for potential confounders. There was a linear trend correlation between serum prealbumin concentration and risk for in-hospital mortality, ICU admission, and mechanical ventilation in elderly patients with COVID-19 infection. CONCLUSION: Prealbumin is an independent risk factor of in-hospital mortality for elderly patients with COVID-19. Assessment of prealbumin may help identify high-risk individuals ≥65 y of age with COVID-19.


Assuntos
Betacoronavirus , Infecções por Coronavirus/sangue , Infecções por Coronavirus/mortalidade , Mortalidade Hospitalar , Pneumonia Viral/sangue , Pneumonia Viral/mortalidade , Pré-Albumina/análise , Idoso , Biomarcadores/sangue , COVID-19 , China/epidemiologia , Feminino , Humanos , Unidades de Terapia Intensiva/estatística & dados numéricos , Modelos Logísticos , Masculino , Análise Multivariada , Razão de Chances , Pandemias , Respiração Artificial/estatística & dados numéricos , Medição de Risco , Fatores de Risco , SARS-CoV-2
15.
Clin Infect Dis ; 71(16): 2079-2088, 2020 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-32361723

RESUMO

BACKGROUND: This study aimed to develop mortality-prediction models for patients with coronavirus disease-2019 (COVID-19). METHODS: The training cohort included consecutive COVID-19 patients at the First People's Hospital of Jiangxia District in Wuhan, China, from 7 January 2020 to 11 February 2020. We selected baseline data through the stepwise Akaike information criterion and ensemble XGBoost (extreme gradient boosting) model to build mortality-prediction models. We then validated these models by randomly collected COVID-19 patients in Union Hospital, Wuhan, from 1 January 2020 to 20 February 2020. RESULTS: A total of 296 COVID-19 patients were enrolled in the training cohort; 19 died during hospitalization and 277 discharged from the hospital. The clinical model developed using age, history of hypertension, and coronary heart disease showed area under the curve (AUC), 0.88 (95% confidence interval [CI], .80-.95); threshold, -2.6551; sensitivity, 92.31%; specificity, 77.44%; and negative predictive value (NPV), 99.34%. The laboratory model developed using age, high-sensitivity C-reactive protein, peripheral capillary oxygen saturation, neutrophil and lymphocyte count, d-dimer, aspartate aminotransferase, and glomerular filtration rate had a significantly stronger discriminatory power than the clinical model (P = .0157), with AUC, 0.98 (95% CI, .92-.99); threshold, -2.998; sensitivity, 100.00%; specificity, 92.82%; and NPV, 100.00%. In the subsequent validation cohort (N = 44), the AUC (95% CI) was 0.83 (.68-.93) and 0.88 (.75-.96) for the clinical model and laboratory model, respectively. CONCLUSIONS: We developed 2 predictive models for the in-hospital mortality of patients with COVID-19 in Wuhan that were validated in patients from another center.


Assuntos
COVID-19/mortalidade , COVID-19/virologia , Coronavirus/patogenicidade , Adulto , Aspartato Aminotransferases/metabolismo , COVID-19/epidemiologia , China/epidemiologia , Estudos de Coortes , Coronavirus/enzimologia , Feminino , Taxa de Filtração Glomerular/fisiologia , Mortalidade Hospitalar , Humanos , Masculino , Pessoa de Meia-Idade
16.
EPMA J ; 11(2): 139-145, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32419876

RESUMO

BACKGROUND: Changes in platelet count are common in COVID-19 patients. The platelet count reflects the thrombocyte turnover, acting as a sensitive indicator of illness severity that is of great clinical utility to monitor a quickly changing health condition of patients affected by aggressive viral infections. This study aims to investigate the significance of platelet count during the progression of the disease in COVID-19 patients. METHODS: A total of 532 COVID-19 patients were involved in the cohort study from the First People's Hospital of Jiangxia District in Wuhan from January 7, 2020, to February 28, 2020. We collected the clinical characteristics and laboratory data of patients. Patients still hospitalized before February 29, 2020, died on admission, with malignant tumors, previous gastrointestinal surgery, missing baseline platelet count, or platelet count detected only once, were excluded. We used a generalized additive model and generalized additive mixed model to compare trends in platelet count over time among survivors and non-survivors, with an adjustment for potential confounders. RESULTS: During the follow-up, twenty-nine subjects died (mortality rate, 5.45%). The platelets among non-survivors decreased and among survivors increased gradually within 1 week after admission. In addition, the difference between the two groups showed an increasing trend during 1 week after admission. This difference increased by an average of 5.3 × 10^9/L daily. CONCLUSIONS: In the early stage, platelet count can dynamically reflect the pathophysiological changes in COVID-19 patients. Early decrease in platelet count was associated with mortality in patients with COVID-19. Causality, however, cannot be deduced from our data.

17.
Arch Biochem Biophys ; 660: 108-120, 2018 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-30365934

RESUMO

Poor cell viability after transplantation has restricted the therapeutic capacity of mesenchymal stem cells (MSCs) for cardiac dysfunction after myocardial infarction (MI). Growth arrest-specific gene 6 (Gas6) encodes a secreted γ-carboxyglutamic acid (Gla)-containing protein that functions in cell growth, adhesion, chemotaxis, mitogenesis and cell survival. In this study, we genetically modified MSCs with Gas6 and evaluated cell survival, cardiac function, and infarct size in a rat model of MI via intramyocardial delivery. Functional studies demonstrated that Gas6 transfer significantly reduced MSC apoptosis, increased survival of MSCs in vitro and in vivo, and that Gas6-engineered MSCs (MSCGas6)-treated animals had smaller infarct size and showed remarkably functional recovery as compared with control MSCs (MSCNull)-treated animals. Mechanistically, Gas6 could enhance phosphatidylinositol 3-kinase (PI3K)/Akt signaling and improve hypoxia-inducible factor-1 alpha (HIF-1α)-driven secretion of four major growth factors (VEGF, bFGF, SDF and IGF-1) in MSCs under hypoxia in an Axl-dependent autocrine manner. The paracrine action of MSCGas6 was further validated by coculture neonatal rat cardiomyocytes with conditioned medium from hypoxia-treated MSCGas6, as well as by pretreatment cardiomyocytes with the specific receptor inhibitors of VEGF, bFGF, SDF and IGF-1. Collectively, our data suggest that Gas6 may advance the efficacy of MSC therapy for post-infarcted heart failure via enhanced Gas6/Axl autocrine prosurvival signaling and paracrine cytoprotective action.


Assuntos
Comunicação Autócrina/genética , Técnicas de Transferência de Genes , Peptídeos e Proteínas de Sinalização Intercelular/genética , Células-Tronco Mesenquimais/patologia , Isquemia Miocárdica/genética , Isquemia Miocárdica/patologia , Comunicação Parácrina/genética , Animais , Hipóxia Celular/genética , Sobrevivência Celular/genética , Feminino , Regulação da Expressão Gênica , Células HEK293 , Humanos , Masculino , Infarto do Miocárdio/complicações , Isquemia Miocárdica/complicações , Isquemia Miocárdica/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos , Ratos Sprague-Dawley , Proteína X Associada a bcl-2/metabolismo
18.
Eur J Intern Med ; 38: 52-60, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28341307

RESUMO

BACKGROUND: Evolocumab (AMG 145), a PCSK9 inhibitor, has been shown to decrease low-density lipoprotein cholesterol (LDL-C) levels. Doses of 140mg administered every 2weeks (Q2W) and 420mg administered every 4weeks (Q4W) are widely used, and both dosing schedules were effective in clinical trials. However, some researchers have speculated that 140mg Q2W administration has equal or even greater efficacy. This meta-analysis was performed to assess the differences in efficacy and safety between the two doses. METHODS: We searched the PubMed, EMBASE, and Web of Science databases to identify relevant clinical trials published before January 2016. A total of 2403 patients from 8 randomized controlled trials were identified and included in the analysis. RESULTS: Evolocumab administered at 140mg Q2W resulted in a greater percent change from baseline in LDL-C concentration (-7.27; 95% confidence interval (CI), -10.36 to -4.18) and had greater efficacy in achieving the treatment goal of LDL-C ≤1.8mmol/L with an relative risk (RR) of 1.09 (95% CI, 1.00 to 1.18) compared with 420mg Q4W in patients who were concomitantly treated with statins. These findings were not significantly different between the 140mg Q2W and 420mg Q4W groups when evolocumab was administered as monotherapy. There was no difference in the rate of occurrence of the main treatment-related adverse events between the two doses. CONCLUSIONS: Evolocumab administered at 140mg Q2W was more effective than the 420mg Q4W dosage at lowering lipid concentrations, especially in patients who concomitantly received stable statin therapy.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Anticolesterolemiantes/administração & dosagem , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hipercolesterolemia/tratamento farmacológico , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais Humanizados , LDL-Colesterol/sangue , Relação Dose-Resposta a Droga , Esquema de Medicação , Quimioterapia Combinada , Humanos , Inibidores de PCSK9 , Viés de Publicação , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
19.
J Huazhong Univ Sci Technolog Med Sci ; 36(6): 796-800, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27924517

RESUMO

Previous investigations have shown that changes in total prostate volume (TPV) are highly variable among aging men, and a considerable proportion of aging men have a stable or decreasing prostate size. Although there is an abundance of literature describing prostatic enlargement in association with benign prostatic hyperplasia, less is known about the appropriate age cut-off points for TPV growth rate. In this community-based cohort study, TPV was examined once a year in men who had consecutive health checkup, during a follow-up of 4 years. A total of 5058 men (age 18-92 years old) were included. We applied multiple regression analyses to estimate the correlation between TPV growth rate and age. Overall, 3232 (63.9%) men had prostate growth, and 1826 (36.1%) had a stable or decreased TPV during the study period. The TPV growth rate was correlated negatively with baseline TPV (r=-0.32, P<0.001). Among 2620 men with baseline TPV <15 cm3, the TPV growth rate increased with age (ß=0.98, 95% CI: 0.77%-1.18%) only up to 53 years old. Among 2188 men with baseline TPV of 15-33.6 cm3, the TPV growth rate increased with age (ß=0.84, 95% CI, 0.66%-1.01%) only up to 61 years old after adjusting for factors of hypertension, obesity, baseline TPV, diabetes mellitus and dyslipidemia. In this longitudinal study, the TPV growth rate increased negatively with baseline TPV, only extending to a certain age and not beyond. Further research is needed to identify the mechanism underlying such differences in prostate growth.


Assuntos
Próstata/crescimento & desenvolvimento , Hiperplasia Prostática/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , China , Humanos , Hipertensão/epidemiologia , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Tamanho do Órgão , Próstata/patologia , Características de Residência/estatística & dados numéricos
20.
Lipids ; 50(3): 241-51, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25638063

RESUMO

Atherosclerosis is characterized by endothelial dysfunction, lipid deposition, fibro-proliferative reactions and inflammation. Octacosanol is a high-molecular-weight primary aliphatic alcohol. As the main component of a cholesterol-lowering drug, octacosanol could inhibit lipids accumulation and cholesterol metabolism. To explore the indication of octacosanol on endothelial protection, we evaluated its effects on the proliferation and migration of human umbilical vein endothelial cells (HUVEC). Cell viability assay using methyl thiazolyl tetrazolium and 5-ethynyl-2'-deoxyuridine revealed that 3.125 µg/ml octacosanol promoted the proliferation of HUVEC. A cell migration assay indicated that 0.781 and 3.125 µg/ml octacosanol increased the migration of HUVEC. Moreover, the phosphorylation levels of Akt and Erk1/2 were significantly elevated under exposure to octacosanol. Blocking the activation of Akt and Erk with their potent inhibitors LY294002 and PD98059, respectively, markedly attenuated the octacosanol-induced proliferation and migration of HUVEC. These findings demonstrated for the first time that octacosanol enhanced the proliferation and migration of HUVEC and mediated these effects through activation of the PI3K/Akt and MAPK/Erk1/2 signaling pathways.


Assuntos
Anticolesterolemiantes/farmacologia , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Álcoois Graxos/farmacologia , Células Endoteliais da Veia Umbilical Humana/citologia , Transdução de Sinais , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Proteína Oncogênica v-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo
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