Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Sci Rep ; 14(1): 13065, 2024 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-38844829

RESUMEN

The TBS is a new method for clinicians to assess the bone quality. It is directly related to the mechanical strength of bone and helps predict fracture risk. The present analysis aimed to investigate the associations between serum PTH levels and TBS by analyzing data from the National Health and Nutrition Examination Survey (NHANES). A total of 3516 participants from the NHANES 2005-2006 were included in this cross-sectional study. The independent variable was serum PTH, and the outcome variable was TBS. The associations of serum PTH levels with TBS were examined using multivariable linear regression models. After adjusting for covariates, there was a negative association between serum PTH level and TBS (ß = - 0.0034; 95% confidence interval, - 0.0050 to - 0.0017). However, in the subgroup analysis stratified by gender, race, and age, this association became negative only in Non-Hispanic White (ß = - 0.0047, 95% CI: -  0.0071 to -  0.0048) and young people (age < 60) (ß = - 0.0036, 95% CI: - 0.0057, - 0.0016), regardless of gender. In addition, the association of serum PTH with TBS was an U-shaped curve, with a point of inflection at 6.71 pmol/L. This study showed that serum PTH level was negatively associated with TBS. Maintaining PTH levels in a lower reasonable clinical range may be beneficial to bone health, especially for young non-Hispanic white.


Asunto(s)
Hueso Esponjoso , Encuestas Nutricionales , Hormona Paratiroidea , Humanos , Hormona Paratiroidea/sangre , Masculino , Femenino , Estudios Transversales , Persona de Mediana Edad , Adulto , Densidad Ósea , Anciano
2.
Ther Clin Risk Manag ; 20: 325-334, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38827486

RESUMEN

Purpose: Percutaneous endoscopic transforaminal lumbar interbody fusion (PE-TLIF) has become one of the most popular minimally invasive surgeries today. However, the issue of hidden blood loss (HBL) in this surgery has received little attention. This study aims to examine the HBL in PE-TLIF surgery and the effect of tranexamic acid (TXA) on blood loss. Methods: In our research, We conducted a retrospective analysis of 300 patients who underwent PE-TLIF from September 2019 to August 2023. They were divided into 2 groups based on whether they received intravenous TXA injection before surgery. The variables compared included: demographic data, pre-and postoperative hemoglobin (HB), hematocrit (HCT), platelets (PLT), red blood cells (RBC), total blood loss (TBL), visible blood loss (VBL), HBL, operation time, postoperative hospital stay, inflammatory markers, coagulation parameters, and adverse events. Results: Regarding demographic characteristics, besides the operation time, no significant differences were observed between the two groups. Compared with the control group, the TXA group showed a significant reduction trend in TBL, HBL, and VBL (P < 0.05). On the first day after surgery, there were significant differences in prothrombin (PT), activated partial thromboplastin time (APTT), and D-dimer (D-D) levels between the two groups. Similarly, HCT also found similar results on the third day after surgery. No adverse events occurred in either group. Conclusion: Research has found that there is a significant amount of HBL in patients undergoing PE-TLIF. Intravenous injection of TXA can safely and effectively reduce perioperative HBL and VBL. Additionally, compared to the control group, the TXA group shows a significant reduction in operation time.

3.
Angew Chem Int Ed Engl ; : e202407748, 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38818639

RESUMEN

Selective producing ethanol from CO2 electroreduction is highly demanded, yet the competing ethylene generation route is commonly more thermodynamically preferred. Herein, we reported an efficient CO2-to-ethanol conversion (53.5% faradaic efficiency at -0.75 V versus reversible hydrogen electrode (vs. RHE)) over an oxide-derived nanocubic catalyst featured with abundant "embossment-like" structured grain-boundaries. The catalyst also attains a 23.2% energy efficiency to ethanol within a flow cell reactor. In situ spectroscopy and electrochemical analysis identified that these dualphase Cu(I) and Cu(0) sites stabilized by grain-boundaries are very robust over the operating potential window, which maintains a high concentration of co-adsorbed *CO and hydroxyl (*OH) species. Theoretical calculations revealed that the presence of *OHad not only promote the easier dimerization of *CO to form *OCCO (ΔG ~ 0.20 eV) at low overpotentials but also preferentially favor the key *CHCOH intermediate hydrogenation to *CHCHOH (ethanol pathway) while suppressing its dehydration to *CCH (ethylene pathway), which is believed to determine the remarkable ethanol selectivity. Such imperative intermediates associated with the bifurcation pathway were directly distinguished by isotope labelling in situ infrared spectroscopy. Our work promotes the understanding of bifurcating mechanism of CO2ER-to-hydrocarbons more deeply, providing a feasible strategy for the design of efficient ethanol-targeted catalysts.

4.
Front Endocrinol (Lausanne) ; 14: 1252968, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37955003

RESUMEN

Background: Observational studies have suggested associations between serum urate levels and sarcopenia, but the causality underlying this correlation remains uncertain. The principal objective of this study is to investigate a causal relationship of serum urate levels with sarcopenia-related traits (hand grip strength, lean mass, walking pace) using bidirectional two-sample Mendelian randomization (MR) approach. The utilization of MR methodology serves to minimize bias caused by reverse causality and confounding factors from observational studies. Methods: The summary statistics of serum urate levels were derived from a cohort consisting of 288,659 individuals participating in CKDGen study. The parameters of right-hand grip strength (N=461,089), left-hand grip strength (N=461,026), appendicular lean mass (ALM) (N=450,243), whole-body lean mass(N=454,850),right-leg fat-free mass(FFM;N=454,835),left-leg FFM(N=454,805), right-arm FFM(N=454,753),left-arm FFM(N=454,672) and walking pace (N=459,915)were sourced from the UK Biobank. MR analysis was conducted utilizing inverse variance weighted (IVW), weighted median, and MR-Egger to evaluate causality. Sensitivity analysis was performed using Cochran's Q test, MR-Egger intercept test, leave-one-out analysis and the funnel plot. Results: IVW estimates demonstrated that serum urate levels exhibited no causal association with sarcopenia-related traits. In the inverse MR investigation, we had exclusively discerned an inverse correlation between walking pace and serum urate levels. No compelling evidence had surfaced to substantiate any association of other sarcopenia-related traits with serum urate. Supplemental MR methods consistently validated the findings obtained from the primary analysis. Sensitivity analysis demonstrated the robustness of findings. Conclusion: Our MR study revealed the absence of the bidirectional causal relationship between serum urate levels and sarcopenia. It is imperative to acknowledge that advanced age and an individual's health status are pivotal determinants influencing urate level and the initiation and advancement of sarcopenia. However, it is worth underscoring that these aspects remain unexamined within the purview of this study. Thus, future investigations should delve deeper into these intricate facets.


Asunto(s)
Fuerza de la Mano , Sarcopenia , Humanos , Análisis de la Aleatorización Mendeliana , Sarcopenia/genética , Ácido Úrico , Causalidad
5.
BMC Endocr Disord ; 23(1): 246, 2023 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-37940909

RESUMEN

OBJECTIVE: The association between segmental body composition and bone mineral density (BMD) remains uncertain. The primary aim of this cross-sectional investigation was to elucidate the connection between segmental body composition and BMD within the United States adult population. METHODS: We selected a cohort of 10,096 individuals from the National Health and Nutrition Examination Survey (NHANES) database, with a mean age of 39 years and a mean BMI of 28.5 kg/m². The parameter of segmental body composition was achieved by quantifying body fat and lean mass percentages across various anatomical regions, including the torso, Android, Gynoid, arms and legs. We conducted a weighted multivariate linear regression analysis to investigate the association between segmental body composition and total BMD. Additionally, subgroup analysis was performed based on age and gender. RESULTS: We found an inverse association between fat proportion in each anatomical region and total BMD, with the arm and leg regions demonstrating the most significant negative correlation. Conversely, a positive correlation was observed between lean mass and BMD across all anatomical regions. These associations remained consistent in subgroup analyses. CONCLUSION: Our investigation revealed a negative association between adipose levels in various anatomical regions and BMD among Americans aged 20 to 59. Importantly, higher fat proportion in the extremities exerted the most deleterious impact on BMD. Furthermore, an increase in lean mass within each anatomical region was ascertained to confer a positive effect on bone health. Consequently, the evaluation of segmental body composition is well-positioned to predict bone health status.


Asunto(s)
Composición Corporal , Densidad Ósea , Adulto , Humanos , Encuestas Nutricionales , Estudios Transversales , Tejido Adiposo/metabolismo , Absorciometría de Fotón , Índice de Masa Corporal
6.
Sci Rep ; 13(1): 10682, 2023 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-37393338

RESUMEN

The relationship between the accumulation of fat in visceral or subcutaneous tissue and bone mineral density (BMD) remains unclear. Our primary objective in this study was to illuminate this relationship by conducting an investigation on a vast scale, encompassing a nationally representative population in the United States. A weighted multiple linear regression model was established to evaluate the relationship between visceral fat, subcutaneous fat, and BMD. Additionally, the exploration of the potential nonlinear relationship was conducted employing the methodology of smooth curve fitting. In order to determine potential inflection points, a two-stage linear regression model was utilized. A total of 10,455 participants between the ages of 20 and 59 were included in this study. Various weighted multiple linear regression models revealed a negative correlation between lumbar BMD and visceral mass index (VMI) and subcutaneous mass index (SMI). However, the association between VMI and lumbar BMD displayed a U-shaped pattern upon employing the smooth curve fitting, and the inflection point of 0.304 kg/m2was determined using a two-stage linear regression model. Our findings indicated a negative association between subcutaneous fat and BMD. A U-shaped relationship was observed between visceral fat and BMD.


Asunto(s)
Densidad Ósea , Grasa Subcutánea , Adulto , Humanos , Adulto Joven , Persona de Mediana Edad , Estudios Transversales , Grasa Subcutánea/diagnóstico por imagen , Tejido Subcutáneo , Grasa Intraabdominal
7.
Chemistry ; 29(46): e202301455, 2023 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-37283568

RESUMEN

Electrochemical CO2 reduction reaction (CO2 RR) provides a promising approach for sustainable chemical fuel production of carbon neutrality. Neutral and alkaline electrolytes are predominantly employed in the current electrolysis system, but with striking drawbacks of (bi)carbonate (CO3 2- /HCO3 - ) formation and crossover due to the rapid and thermodynamically favourable reaction between hydroxide (OH- ) with CO2 , resulting in low carbon utilization efficiency and short-lived catalysis. Very recently, CO2 RR in acidic media can effectively address the (bi)carbonate issue; however, the competing hydrogen evolution reaction (HER) is more kinetically favourable in acidic electrolytes, which dramatically reduces CO2 conversion efficiency. Thus, it is a big challenge to effectively suppress HER and accelerate acidic CO2 RR. In this review, we begin by summarizing the recent progress of acidic CO2 electrolysis, discussing the key factors limiting the application of acidic electrolytes. We then systematically discuss addressing strategies for acidic CO2 electrolysis, including electrolyte microenvironment modulation, alkali cations adjusting, surface/interface functionalization, nanoconfinement structural design, and novel electrolyzer exploitation. Finally, the new challenges and perspectives of acidic CO2 electrolysis are suggested. We believe this timely review can arouse researchers' attention to CO2 crossover, inspire new insights to solve the "alkalinity problem" and enable CO2 RR as a more sustainable technology.

8.
Chem Commun (Camb) ; 59(27): 4051-4054, 2023 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-36929395

RESUMEN

Dearomatization reactions provide a rapid approach to construct complicated molecules that are difficult to synthesize by traditional methods from simple aromatic compounds. Herein, we report an efficient dearomative [3+2] cycloaddition reaction of 2-alkynyl pyridines with diarylcyclopropenones, leading to the synthesis of densely functionalized indolizinones in moderate to good yields under metal-free conditions. In addition, this strategy can also be employed in dearomative cyclization of isoquinolines to access a variety of benzo-fused indolizinones. Density functional theory (DFT) calculations revealed that an appropriate substituent at the 2-position of pyridine is crucial to the dearomatization process.

9.
Org Lett ; 24(17): 3238-3243, 2022 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-35446037

RESUMEN

The innovative construction of novel N,O-bidentate ligands represents a long-standing challenge for chemists. Here, we report an unprecedented approach for the construction of N,O-bidentate derivatives via the merging of ring deconstruction with cycloaromatization of indolizines and cyclopropenones. Without any catalysts, our method can deliver a series of polyaryl 2-(pyridin-2-yl)phenols in excellent yields. In addition, N,O-bidentate organic BF2 complexes can also be constructed via this one-pot protocol.

10.
J Org Chem ; 2021 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-34132097

RESUMEN

A straightforward and novel controllable site-selective construction of 2- and 4-substituted pyrimido[1,2-b]indazole from 3-aminoindazoles and ynals has been developed. The high regioselectivity of this reaction could be easily switched by converting different catalytic systems. In this way, a series of 2- and 4-substituted pyrimido[1,2-b]indazole derivatives were obtained in moderate to good yields. In addition, the photophysical properties of compound 3a prepared by the present method were discussed.

11.
Org Lett ; 23(7): 2754-2759, 2021 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-33739117

RESUMEN

A direct cascade cyclization of 3-aminoindazoles, ynals, and accessible chalcogens facilitated by visible light has been developed. A series of fluoroactive selenium/tellurium-substituted pyrimido[1,2-b]-indazoles were easily accessed in moderate to good yields with a broad scope. Furthermore, we surveyed the spectral properties of selenide pyrimido[1,2-b]-indazoles prepared by this method.

12.
Oncol Lett ; 20(4): 36, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32802160

RESUMEN

Chimeric antigen receptor (CAR) T cells have an unprecedented positive curative effect for hematological malignances. Most notably, cluster of differentiation 19 (CD19) CAR T-cell therapy for pediatric acute lymphoblastic leukemia is associated with a high complete remission rate and has aroused considerable attention in the medical field. However, it also causes a series of adverse reactions and increases the risk of recurrence. The present review examines the results of CD19 CAR T-cell therapy and lists its adverse effects. In addition, some of the mechanisms of recurrence are characterized and applicable strategies to address this challenging problem are proposed.

13.
J Org Chem ; 85(4): 2406-2414, 2020 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-31870155

RESUMEN

A new and efficient strategy for enynes cyclization catalyzed by triflic acid has been described. Various valuable carbocycle-fused and heterocycle-fused ketones were easily accessed by the formation of new C-C and C-O bond under benign reaction conditions. This protocol also provides another opportunity to construct polycyclic single-nitrogen ketones via a cation-induced cascade cyclization of polyenynes. Furthermore, antiviral bioassays revealed that a few compounds exhibited good antiviral activity against tobacco mosaic virus at a concentration of 200 µg mL-1.


Asunto(s)
Alquinos , Carbón Orgánico , Catálisis , Ciclización , Isomerismo , Mesilatos , Estructura Molecular
14.
Biomed Pharmacother ; 103: 308-316, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29656187

RESUMEN

Sirtuin1 (SIRT1) belongs to the mammalian sirtuin family and plays an important role in deacetylating histones and non-histones. SIRT1 is associated with tumor metastasis in several tumors. However, the effect of SIRT1 on the mechanism of metastasis in resistant esophageal cancer remains unclear. In this study, we demonstrated that increased migration and invasion in drug-resistant esophageal cancer cells (EC109/PTX, TE-1/PTX). Our experiments revealed that the selective SIRT1 inhibitor (EX527) significantly suppressed cells migrate and inhibited the occurrence of the epithelial-mesenchymal transition (EMT), thereby altering the invasiveness and metastatic potential of the esophageal cancer cell lines. In addition, we observed that the inhibition of SIRT1 could alter the expression of snail. In conclusion, these results indicate that SIRT1 may promote the transformation of tumor cells by inducing the EMT and may serve as a potential molecular target for the treatment of resistant esophageal cancer.


Asunto(s)
Transformación Celular Neoplásica/metabolismo , Transformación Celular Neoplásica/patología , Transición Epitelial-Mesenquimal , Neoplasias Esofágicas/patología , Sirtuina 1/metabolismo , Animales , Biomarcadores de Tumor/metabolismo , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Regulación hacia Abajo/genética , Transición Epitelial-Mesenquimal/genética , Neoplasias Esofágicas/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Técnicas de Inactivación de Genes , Humanos , Concentración 50 Inhibidora , Ratones Desnudos , Invasividad Neoplásica , Metástasis de la Neoplasia
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...