Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 168
Filtrar
1.
Artículo en Inglés | MEDLINE | ID: mdl-38976037

RESUMEN

PURPOSE: To systematically investigate kinetic metrics and metabolic trapping of [13N]NH3 in organs. METHODS: Eleven participants performed total-body [13N]NH3 dynamic positron emission tomography (PET). Regions of interest were drawn in organs to obtain time-to-activity curves (TACs), which were fitted with an irreversible two-tissue compartment model (2TC) to investigate constant rates K1, k2 and k3, and to calculate Ki. Additionally, one-tissue compartment model using full data (1TCfull) and the first four minutes of data (1TC4min) were fitted to TAC data. K1 and k2 were compared among different models to assess [13N]NH3 trapping in organs. RESULTS: Kinetic rates of [13N]NH3 varied significantly among organs. The mean K1 ranged from 0.049 mL/cm3/min in the muscle to 2.936 mL/cm3/min in the kidney. The k2 and k3 were lowest in the liver (0.001 min- 1) and in the pituitary (0.009 min- 1), while highest in the kidney (0.587 min- 1) and in the liver (0.800 min- 1), respectively. The Ki was largest in the myocardium (0.601 ± 0.259 mL/cm3/min) while smallest in the bone marrow (0.028 ± 0.022 mL/cm3/min). Three groups of organs with similar kinetic characteristics were revealed: (1) the thyroid, the lung, the spleen, the pancreas, and the kidney; (2) the liver and the muscle; and (3) the cortex, the white matter, the cerebellum, the pituitary, the parotid, the submandibular gland, the myocardium, the bone, and the bone marrow. Obvious k3 was identified in multiple organs, and significant changes of K1 in multiple organs and k2 in most organs were found between 2TC and 1TCfull, but both K1 and k2 were comparable between 2TC and 1TC4min. CONCLUSION: The kinetic rates of [13N]NH3 differed among organs with some have obvious 13N-anmmonia trapping. The normal distribution of kinetic metrics of 13N-anmmonia in organs can serve as a reference for its potential use in tumor imaging.

2.
Arch Dermatol Res ; 316(6): 304, 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38819652

RESUMEN

For dupilumab, real-world long-term follow-up data remain scarce, and studies on optimized treatment modes as well as drug survival rate and its predictors are lacking. To explore the effectiveness of different treatment modes of dupilumab and to understand the drug survival rates of dupilumab in China and its predictive factors. This retrospective study included patients with moderate-to-severe AD who received dupilumab treatment. Their clinical data were collected and analyzed. Compared with baseline, the SCORing Atopic Dermatitis (SCORAD), Eczema Area and Severity Index (EASI), numerical rating scale (NRS), and Atopic Dermatitis Control Tool (ADCT) scores significantly decreased at 12, 24, and 52 weeks (p < 0.0001), and the continuous medication group had more significant improvements in SCORAD, EASI, NRS, and ADCT scores at 52 weeks than the noncontinuous medication group (p < 0.05). The 6-month and 1-year drug survival rates of dupilumab were 59.7% and 51.9%, respectively. The most common reason for treatment discontinuation was the satisfactory control of AD. Patients with adult-onset AD (adjusted odds ratio [OR]: 0.15, 95% confidence interval [CI]: 0.03-0.73) , not complicated by other systemic diseases (adjusted OR: 0.17, 95% CI: 0.04-0.84) and eosinophilia at baseline (adjusted OR: 3.71, 95% CI: 1.12-12.26) had a higher probability of drug discontinuation. In real-world practice in China, dupilumab has exhibited good long-term effectiveness and safety for the treatment of moderate-to-severe AD, and continuous administration can benefit patients in the long term.


Asunto(s)
Anticuerpos Monoclonales Humanizados , Dermatitis Atópica , Índice de Severidad de la Enfermedad , Humanos , Dermatitis Atópica/tratamiento farmacológico , Dermatitis Atópica/diagnóstico , Estudios Retrospectivos , Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticuerpos Monoclonales Humanizados/administración & dosificación , Anticuerpos Monoclonales Humanizados/efectos adversos , Femenino , Masculino , Adulto , China/epidemiología , Resultado del Tratamiento , Persona de Mediana Edad , Adulto Joven , Adolescente , Niño , Estudios de Seguimiento
3.
Oral Oncol ; 152: 106755, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38547780

RESUMEN

OBJECT: Previous studies suggest BRAFV600E mutation is a marker for poor prognosis in papillary thyroid cancer, however, its ability to further risk stratify papillary thyroid microcarcinoma (PTMC) remains controversial. We aimed to explore the association between BRAFV600E mutation and the clinicopathological features and recurrence in Chinese PTMC patients. METHODS: We retrospectively reviewed 2094 PTMC patients who underwent surgery and had a valid BRAFV600E mutation test result. Among them, 1292 patients had complete follow-up data. The mutation incidence was determined. Moreover, the clinicopathological characteristics, disease-free survival (DFS), and response to therapy distribution were compared between the mutation and non-mutation groups. RESULTS: BRAFV600E mutation was observed in 90.6 % of all patients and 89.2 % of patients with complete follow-up data. No significant difference was observed in lymph node metastases (LNM) number categories between the mutation and non-mutation groups among all patients (P = 0.329) and 1292 patients (P = 0.408). Neither the 3-year DFS (97.9 % vs. 98.0 %, P = 0.832) nor the response to therapy distribution (P > 0.05) indicated a significant difference between the mutation and non-mutation groups. The 3-year DFS differs among patients having different LNM number categories (99.8 % vs. 98.5 % vs. 77.3 %, P < 0.001). Multivariate analysis revealed that high-volume (over 5) LNM (Total thyroidectomy (TT): OR = 4.000, 95 % CI 2.390-6.694, P < 0.001; Unilateral thyroidectomy (UT): OR = 4.183, 95 % CI 1.565-11.190, P = 0.004), rather than BRAFV600E mutation (P > 0.05), was an independent risk factor of response to therapy. CONCLUSIONS: Our results suggested that BRAFV600E mutation could not accurately predict LNM or the recurrence of Chinese PTMC patients. Moreover, high-volume LNM is significantly associated with PTMC prognosis.


Asunto(s)
Mutación , Proteínas Proto-Oncogénicas B-raf , Neoplasias de la Tiroides , Humanos , Femenino , Masculino , Neoplasias de la Tiroides/genética , Neoplasias de la Tiroides/patología , Neoplasias de la Tiroides/terapia , Persona de Mediana Edad , Proteínas Proto-Oncogénicas B-raf/genética , Adulto , Estudios Retrospectivos , Carcinoma Papilar/genética , Carcinoma Papilar/patología , Anciano , Recurrencia Local de Neoplasia/genética , Pronóstico , Adulto Joven
4.
Angew Chem Int Ed Engl ; 63(8): e202314790, 2024 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-38185472

RESUMEN

A mild photoredox catalyzed construction of sulfides, disulfides, selenides, sulfoxides and sulfones from unstrained ketone precursors is introduced. Combination of this deacylative process with SN 2 or coupling reactions provides novel and convenient modular strategies toward unsymmetrical or symmetric disulfides. Reactivity studies favor a bromine radical that initiates a HAT (Hydrogen Atom Transfer) from the aminal intermediate resulting in expulsion of a C-centered radical that is intercepted to make C-S and C-Se bonds. Gram scale reactions, broad substrate scope and tolerance towards various functional groups render this method appealing for future applications in the synthesis of organosulfur and selenium complexes.

5.
J Comput Chem ; 45(6): 321-330, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-37861354

RESUMEN

Cyclometalated Pt(II) complexes are popular phosphorescent emitters with color-tunable emissions. To render their practical applications as organic light-emitting diodes emitters, it is required to develop Pt(II) complexes with high radiative decay rate constant and photoluminescence (PL) quantum yield. Here, a general protocol is developed for accurate predictions of emission wavelength, radiative decay rate constant, and PL quantum yield based on the combination of first-principles quantum mechanical method, machine learning, and experimental calibration. A new dataset concerning phosphorescent Pt(II) emitters is constructed, with more than 200 samples collected from the literature. Features containing pertinent electronic properties of the complexes are chosen and ensemble learning models combined with stacking-based approaches exhibit the best performance, where the values of squared correlation coefficients are 0.96, 0.81, and 0.67 for the predictions of emission wavelength, PL quantum yield and radiative decay rate constant, respectively. The accuracy of the protocol is further confirmed using 24 recently reported Pt(II) complexes, which demonstrates its reliability for a broad palette of Pt(II) emitters.

6.
Org Biomol Chem ; 21(46): 9133-9137, 2023 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-37974521

RESUMEN

A novel tandem method to synthesize 2-azaaryl indoline promoted by LiN(SiMe3)2 from 2-azaaryl methyl amine and 2-fluoro benzyl bromides was developed. Mechanistic investigation indicated that this tandem cyclization was initiated by selective benzyl C-SN2 substitution followed by an intramolecular SNAr reaction. Diverse 2-azaaryl indoles could also be obtained via simple functional transformations.

7.
Heliyon ; 9(11): e20947, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37954262

RESUMEN

With the widespread application of computer technology in engineering education, Online Judge (OJ) systems have become an important platform for programming teaching. OJ systems provide a platform for learners to practice programming skills, submit solutions, and receive feedback. They offer a conducive environment for learners to engage in hands-on coding exercises and enhance their programming abilities. This article explores the use of OJ systems as a software tool for enhancing programming education in engineering. It investigates how the difficulty and order of programming problems affect the users' behavior, performance, and cognitive load in OJ environments. The research data were sourced from Project_CodeNet. Using statistical methods, such as Spearman correlation analysis and differential analysis, the study reveals the factors that influence the users' submission situations, answer order, and learning outcomes. The findings provide useful implications for OJ system developers, teachers, and learners in designing, implementing, and using OJ systems for programming education in engineering. The study suggests that problem difficulty and order should be considered and adjusted according to the users' abilities and progress, to provide appropriate challenges and support, balance the cognitive load, and improve the programming skills of the users.

8.
Int Immunopharmacol ; 125(Pt A): 111137, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37897946

RESUMEN

Subcutaneous immunotherapy (SCIT) and dupilumab are important treatments for patients with moderate to severe atopic dermatitis (AD). However, in clinical practice, poor response to allergen immunotherapy (AIT) or dupilumab has been observed in some patients. It is unknown whether combining dupilumab and SCIT can improve treatment responses in patients with moderate to severe AD that is resistant to dupilumab or SCIT monotherapy. This single-centre, retrospective, observational, real-world study evaluated the efficacy and safety of dupilumab and SCIT for refractory moderate to severe AD. The data of ten patients with moderate to severe atopic dermatitis who were treated with dupilumab and SCIT were retrospectively analysed. The scoring atopic dermatitis (SCORAD) score, numerical rating scale (NRS), and atopic dermatitis control test (ADCT) scores and eosinophil and total IgE levels before and after add-on therapy were compared and analysed. The SCORAD, NRS, and ADCT scores decreased significantly at four and 12 weeks after the initiation of add-on therapy and plateaued during maintenance treatment. The eosinophil and total IgE levels were not significantly different before and after add-on therapy. No serious adverse reactions were reported in any patient during add-on therapy. This study indicates that the combination of dupilumab and SCIT safely improves the treatment response of patients with moderate to severe AD who are resistant to dupilumab or SCIT monotherapy.


Asunto(s)
Dermatitis Atópica , Humanos , Estudios Retrospectivos , Dermatitis Atópica/tratamiento farmacológico , Resultado del Tratamiento , Inyecciones Subcutáneas , Desensibilización Inmunológica , Inmunoglobulina E , Índice de Severidad de la Enfermedad , Método Doble Ciego
9.
Clin Transl Sci ; 16(11): 2276-2288, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37688349

RESUMEN

Intravenous remdesivir (RDV) is US Food and Drug Administration-approved for hospitalized and nonhospitalized individuals with coronavirus disease 2019. RDV undergoes intracellular metabolic activation to form the active triphosphate, GS-443902, and other metabolites. Alternative administration routes, including localized pulmonary delivery, can lower systemic exposure and maximize exposure at the site of action. This study evaluated the pharmacokinetics (PK) and safety of inhaled RDV in healthy adults. This phase Ia, randomized, placebo-controlled study evaluated inhaled RDV in healthy participants randomized 4:1 to receive RDV or placebo as single doses (4 cohorts) or multiple once-daily doses (3 cohorts). Doses in cohorts 1-6 were administered as an aerosolized solution for inhalation through a sealed facemask; doses in cohort 7 were administered as an aerosolized solution for inhalation through a mouthpiece. Safety was assessed throughout the study. Seventy-two participants were enrolled (inhaled RDV, n = 58 and placebo, n = 14). Following single RDV doses, RDV, GS-704277, and GS-441524 plasma PK parameters indicated dose-proportional increases in area under the concentration-time curve (AUC) extrapolated to infinite time, AUC from time zero to last quantifiable concentration, and maximum observed concentration. Analyte plasma concentrations after multiple RDV doses were consistent with those for single-dose RDV. Analyte plasma exposures were lower when RDV was administered with a mouthpiece versus a sealed facemask. The most common adverse events included nausea, dizziness, and cough. Single- and multiple-dose inhaled RDV exhibited linear and dose-proportional plasma PK. Administration of RDV via inhalation was generally safe and well-tolerated.


Asunto(s)
Alanina , Adulto , Humanos , Voluntarios Sanos , Adenosina Monofosfato/efectos adversos , Alanina/efectos adversos , Método Doble Ciego , Relación Dosis-Respuesta a Droga
10.
Abdom Radiol (NY) ; 48(10): 3127-3134, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37439840

RESUMEN

OBJECTIVE: To investigate the diagnostic value of early dynamic 18F-FDG PET/CT(ED 18F-FDG PET/CT) combined with conventional whole-body 18F-FDG PET/CT(WB 18F-FDG PET/CT) in hepatocellular carcinoma (HCC), as well as the difference of early dynamic blood flow parameters and maximum standardized uptake value (SUVmax) in HCC patients with/without liver cirrhosis or microvascular invasion (MVI). METHODS: Twenty-two consecutive patients (mean age 57.8 years) with 28 established HCC lesions (mean size 4.5 cm) underwent a blood flow study with an 18F-FDG dynamic scan divided into 24 sequences of 5 s each and a standard PET/CT scan. On the ED PET/CT study, an experienced PET/CT physician obtained volumes of interest (VOIs) where three blood flow estimates (time to peak [TTP], blood flow [BF], and hepatic perfusion index [HPI]) were calculated. On the WB PET/CT study, a VOI was placed on the fused scan for each HCC and maximum standardized uptake value (SUVmax) was obtained. Comparison of blood flow estimates, SUVmax, and tumor/background ratio (TNR) was performed among HCCs with and without angioinvasion, as well as HCCs in cirrhotic and non-cirrhotic liver. RESULTS: Compared with WB 18F-FDG PET/CT alone, ED combined with WB 18F-FDG PET/CT can significantly increase the detection rate of moderately differentiated and poorly differentiated HCCs (both P < 0.05). HPI was higher in HCCs in patients with liver cirrhosis than those without liver cirrhosis (P = 0.044). There was no significant difference in TTP, BF, SUVmax, or TNR between HCCs in patients with liver cirrhosis and those without liver cirrhosis. There was no significant difference in blood flow estimates or SUVmax in background liver parenchyma between patients with and those without cirrhosis. TTP was shorter in HCCs with MVI than without MVI (P = 0.046). There was no significant difference in BF, HPI, SUVmax, or TNR between HCCs with MVI and without MVI. There was no significant difference in blood flow estimates or SUVmax in background liver parenchyma between patients with and those without MVI. CONCLUSION: ED combined with WB 18F-FDG PET/CT can significantly increase the detection rate of moderately differentiated and poorly differentiated HCCs. HPI was significantly higher in HCCs in patients with liver cirrhosis than those without liver cirrhosis. TTP was significantly shorter in HCCs with MVI than without MVI.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Persona de Mediana Edad , Carcinoma Hepatocelular/patología , Fluorodesoxiglucosa F18 , Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias Hepáticas/patología , Radiofármacos , Tomografía de Emisión de Positrones , Cirrosis Hepática
11.
Abdom Radiol (NY) ; 48(8): 2537-2546, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37179282

RESUMEN

PURPOSE: 18F-FDG PET/MR has been applied to the diagnosis and preoperative staging in various tumor types; however, reports using PET/MR in hilar cholangiocarcinoma (HCCA) are rare. We investigated the value of PET/MR for preoperative staging and compared it with PET/CT in HCCA. METHODS: Fifty-eight patients with HCCA confirmed by pathology were retrospectively analyzed. 18F-FDG PET/CT imaging was performed first, followed with whole-body PET/MR imaging. SUVmax of tumor and normal liver tissue were measured. Paired T test was used to compare SUVmax of tumor and normal liver tissue of PET/CT and PET/MR. In addition, McNemar test was used to compare the accuracy of TNM staging and Bismuth-Corlette typing between PET/CT and PET/MR. RESULTS: There was no significant difference in SUVmax between PET/CT and PET/MR in primary tumor lesions (6.6 ± 5.5 vs. 6.8 ± 6.2, P = 0.439). SUVmax of PET/CT and PET/MR in normal liver parenchyma was significantly different (3.0 ± 0.5 vs. 2.1 ± 0.5, P < 0.001). The accuracy of PET/MR in diagnosing T staging and N staging was significantly higher than those of PET/CT (72.4% vs. 58.6%, P = 0.022 and 84.5% vs. 67.2%, P = 0.002). There was no significant difference between PET/CT and PET/MR in M staging (94.8% vs. 98.3%, P = 0.5). The classification accuracy of PET/MR in Bismuth-Corlette was significantly higher than that of PET/CT (89.7% vs. 79.3%), P = 0.031. CONCLUSIONS: The diagnostic accuracy of 18F-FDG PET/MR was superior to that of PET/CT in preoperative T staging, N staging, and Bismuth-Corlette classification of HCCA. In M staging, the diagnostic accuracy of PET/MR was similar to that of PET/CT.


Asunto(s)
Neoplasias de los Conductos Biliares , Tumor de Klatskin , Humanos , Tomografía Computarizada por Tomografía de Emisión de Positrones , Fluorodesoxiglucosa F18 , Tumor de Klatskin/patología , Tumor de Klatskin/cirugía , Estadificación de Neoplasias , Estudios Retrospectivos , Bismuto , Neoplasias de los Conductos Biliares/patología
12.
J Nucl Cardiol ; 30(5): 2058-2067, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37095328

RESUMEN

BACKGROUND: The aim of this study was to investigate the feasibility and diagnostic value of myocardial flow reserve (MFR) assessed by rest/stress myocardial perfusion imaging with dynamic single-photon emission computed tomography (SPECT) in the functional evaluation of myocardial bridge (MB). METHODS: From May 2017 to July 2021, patients with angiographically confirmed isolated MB on the left anterior descending artery (LAD) who underwent dynamic SPECT myocardial perfusion imaging were retrospectively included. The assessment of semiquantitative indices of myocardial perfusion (summed stress scores, SSS) and quantitative parameters (MFR) was performed. RESULTS: A total of 49 patients were enrolled. The mean age of the subjects was 61.0 ± 9.0 years. All of the patients were symptomatic, and 16 cases (32.7%) presented with typical angina. SPECT-derived MFR showed a borderline significantly negative correlation with SSS (r = 0.261, P = .070). There was a trend of higher prevalence of impaired myocardial perfusion defined as MFR < 2 than as SSS ≥ 4 (42.9% vs 26.5%; P = .090). CONCLUSION: Our data support that SPECT MFR may be a useful parameter for the functional assessment of MB. In patients with MB, the use of dynamic SPECT could be a potential method for hemodynamic assessment.


Asunto(s)
Enfermedad de la Arteria Coronaria , Reserva del Flujo Fraccional Miocárdico , Puente Miocárdico , Imagen de Perfusión Miocárdica , Humanos , Persona de Mediana Edad , Anciano , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Estudios Retrospectivos , Tomografía Computarizada de Emisión de Fotón Único/métodos , Perfusión , Imagen de Perfusión Miocárdica/métodos , Circulación Coronaria
13.
Small Methods ; 7(7): e2300280, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37086111

RESUMEN

Ni-rich layered cathodes with ultrahigh nickel content (≥90%), for example LiNi0.9 Co0.1 O2 (NC0.9), are promising for next-generation high-energy Li-ion batteries (LIBs), but face stability issues related to structural degradation and side reactions during the electrochemical process. Here, surface modulation is demonstrated by integrating a Li+ -conductive nanocoating and gradient lattice doping to stabilize the active cathode efficiently for extended cycles. Briefly, a wet-chemistry process is developed to deposit uniform ZrO(OH)2 nanoshells around Ni0.905 Co0.095 (OH)2 (NC0.9-OH) hydroxide precursors, followed by high temperature lithiation to create reinforced products featuring Zr doping in the crust lattice decorated with Li2 ZrO3 nanoparticles on the surface. It is identified that the Zr4+ infiltration reconstructed the surface lattice into favorable characters such as Li+ deficiency and Ni3+ reduction, which are effective to combat side reactions and suppress phase degradation and crack formation. This surface control is able to achieve an optimized balance between surface stabilization and charge transfer, resulting in an extraordinary capacity retention of 96.6% after 100 cycles at 1 C and an excellent rate capability of 148.8 mA h g-1 at 10 C. This study highlights the critical importance of integrated surface modulation for high stability of cathode materials in next-generation LIBs.

14.
Infect Dis Ther ; 12(4): 1189-1203, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37074613

RESUMEN

INTRODUCTION: In the PINETREE study, early remdesivir treatment reduced risk of coronavirus disease 2019 (COVID-19)-related hospitalizations or all-cause death versus placebo by 87% by day 28 in high-risk, non-hospitalized patients. Here we report results of assessment of heterogeneity of treatment effect (HTE) of early outpatient remdesivir, focusing on time from symptom onset and number of baseline risk factors (RFs). METHODS: PINETREE was a double-blind, placebo-controlled trial of non-hospitalized patients with COVID-19 who were randomized within 7 days of symptom onset and had ≥ 1 RF for disease progression (age ≥ 60 years, obesity [body mass index ≥ 30], or certain coexisting medical conditions). Patients received remdesivir intravenously (200 mg on day 1 and 100 mg on days 2 and 3) or placebo. RESULTS: In this subgroup analysis, HTE of remdesivir by time from symptom onset at treatment initiation and number of baseline RFs was not detected. Treatment with remdesivir reduced COVID-19-related hospitalizations independent of stratification by time from symptom onset to randomization. Of patients enrolled ≤ 5 days from symptom onset, 1/201 (0.5%) receiving remdesivir and 9/194 (4.6%) receiving placebo were hospitalized (hazard ratio [HR] 0.10; 95% confidence interval [CI] 0.01-0.82). Of those enrolled at > 5 days from symptom onset, 1/78 (1.3%) receiving remdesivir and 6/89 (6.7%) receiving placebo were hospitalized (HR 0.19; 95% CI 0.02-1.61). Remdesivir was also effective in reducing COVID-19-related hospitalizations when stratified by number of baseline RFs for severe disease. Of patients with ≤ 2 RFs, 0/159 (0.0%) receiving remdesivir and 4/164 (2.4%) receiving placebo were hospitalized; of those with ≥ 3 RFs, 2/120 (1.7%) receiving remdesivir and 11/119 (9.2%) receiving placebo were hospitalized (HR 0.16; 95% CI 0.04-0.73). CONCLUSIONS: In the outpatient setting, benefit of remdesivir initiated within 7 days of symptoms appeared to be consistent across patients with RFs. Therefore, it may be reasonable to broadly treat patients with remdesivir regardless of comorbidities. TRIAL REGISTRATION: ClinicalTrials.gov number NCT04501952.

15.
J Am Chem Soc ; 145(13): 7397-7407, 2023 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-36961942

RESUMEN

Nickel-rich layered oxides (NLOs) are considered as one of the most promising cathode materials for next-generation high-energy lithium-ion batteries (LIBs), yet their practical applications are currently challenged by the unsatisfactory cyclability and reliability owing to their inherent interfacial and structural instability. Herein, we demonstrate an approach to reverse the unstable nature of NLOs through surface solid reaction, by which the reconstructed surface lattice turns stable and robust against both side reactions and chemophysical breakdown, resulting in improved cycling performance. Specifically, conformal La(OH)3 nanoshells are built with their thicknesses controlled at nanometer accuracy, which act as a Li+ capturer and induce controlled reaction with the NLO surface lattices, thereby transforming the particle crust into an epitaxial layer with localized Ni/Li disordering, where lithium deficiency and nickel stabilization are both achieved by transforming oxidative Ni3+ into stable Ni2+. An optimized balance between surface stabilization and charge transfer is demonstrated by a representative NLO material, namely, LiNi0.83Co0.07Mn0.1O2, whose surface engineering leads to a highly improved capacity retention and excellent rate capability with a strong capability to inhibit the crack of NLO particles. Our study highlights the importance of surface chemistry in determining chemical and structural behaviors and paves a research avenue in controlling the surface lattice for the stabilization of NLOs toward reliable high-energy LIBs.

16.
Micromachines (Basel) ; 14(2)2023 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-36838054

RESUMEN

The efficient and cost-effective residual stress control method is of great significance for the application of additive manufacturing (AM) technology. In this work, thermal-vibration stress relief (TVSR) with different temperatures and dynamic stresses was performed on Ti6Al4V samples prepared by selective laser melting (SLM), the stress relief effects of TVSR and its influence on phase and microstructure were investigated and compared with thermal stress relief (TSR) and vibration stress relief (VSR), and the stress relief mechanisms of these methods are discussed. It was found that the residual stress relief rate can reach 86.76% after TVSR treatment at a temperature of 380 °C and a dynamic stress of 400 MPa, which increased by 63.63% compared with VSR under the same dynamic stress. The efficiency is increased by 76% compared with TSR at 580 °C and the residual stress relief rate is almost the same. After TVSR, VSR and TSR treatments, the grain morphology, size and phase content of samples were basically unchanged, and low-angle grain boundaries (LAGBs) were increased after TVSR and VSR treatments and decreased after TSR treatment. The results confirm that the TVSR method has the ability to control the residual stress of selective laser melted Ti6Al4V with low time and cost consumption, and are helpful for engineering applications of TVSR.

17.
Polymers (Basel) ; 15(3)2023 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-36771907

RESUMEN

Continuous fiber-reinforced composite 3D printing (CFRC 3DP) has become a hot topic of interest for many experts and scholars. Continuous fiber-reinforced prepreg filament (CFRPF) for printing needs to be prepared in advance. In this paper, on the basis of the resin fusion impregnation theory, a fabrication device was designed for continuous carbon fiber-reinforced polycarbonate prepreg filament (CCFRPF). Then, according to the orthogonal test and the TOPSIS entropy weight optimization theory, the optimization method for CFRPF/PC preparation process parameters was proposed, and the relationship between the preparation process parameters and the performance indexes was discussed. The results show that when preparing CCFRPF/PC, the weight of diameter performance index is the largest, about 0.75. The optimal combination of process parameters for CCFRPF/PC is, respectively, 285 °C for the outlet mold temperature, 305 °C for the impregnation mold temperature, and 1 m/min for the winding speed. In this case, the diameter, roundness, minimum curvature radius and tensile strength of 0.375 mm, 29.4 µm, 9.775 mm and 1298 MPa were achieved, respectively.

18.
J Chem Theory Comput ; 19(5): 1381-1387, 2023 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-36812059

RESUMEN

All-solid-state lithium-ion batteries have been a promising solution for next-generation energy storage due to their safety and potentially high energy density. In this work, we developed a density-functional tight-binding (DFTB) parameter set for modeling solid-state lithium batteries, focusing on the band alignment at electrolyte/electrode interfaces. Despite DFTB being widely applied in the simulation of large-scale systems, parametrization is usually done for single materials, and less attention is paid to band alignment among multiple materials. Band offsets at the electrolyte/electrode interfaces are key quantities determining the performance. Here, an automated global optimization method based on DFTB confinement potentials of all elements is developed, while the band offsets between electrodes and electrolytes are introduced as constraints during the optimization. The parameter set is applied to model an all-solid-state Li/Li2PO2N/LiCoO2 battery, and its electronic structure shows a good agreement with that from density-functional theory (DFT) calculations.

19.
Org Lett ; 25(7): 1166-1171, 2023 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-36786500

RESUMEN

Deconstructive alkynylation of an unstrained ketone catalyzed by an organic photocatalyst under blue light irradiation is reported for the first time. A broad substrate scope with up to 63 examples, excellent functional group tolerance, and gram scale reaction demonstrated the practicality of this novel alkynylation method. The dihydroquinazolinone derivative of trifluoroacetophenone had been proved to have potential as a novel trifluoromethylation reagent after working well for the trifluoromethylation reaction with various alkynyl bromides.

20.
Chin Med ; 18(1): 4, 2023 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-36627680

RESUMEN

Psoralea corylifolia L. (PCL), referred to as "Bu-gu-zhi" in Chinese, has great medicinal values since ancient times. PCL is the dried ripe fruit of Psoralea corylifolia L., which has been widely used in traditional Chinese medicine (TCM) for the treatment of kidney-yang deficiency, enuresis and urinary frequency, chills and pain of the waist and knees, dawn diarrhea and vitiligo. In this paper, a systematic of the botany, traditional uses, phytochemistry, pharmacology, toxicology, quality control and pharmacokinetics of PCL was presented, along with future research directions. According to the results, PCL contains approximately 163 chemical components, including coumarins, flavonoids, monoterpene phenols, benzofurans, glycosides, lipids, fatty acids, and volatile oils. PCL and its active ingredients have a variety of pharmacological activities, such as anti-inflammatory, antibacterial, antiviral, antioxidant, antitumor, antiosteoporosis, cardioprotective, neuroprotective, and immunomodulatory. Further study of quality control standards and potential mechanisms of PCL is also needed. In addition, more toxicological studies will also contribute to the progress of clinical trials.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA