Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 63
Filtrar
1.
Reprod Biomed Online ; 49(3): 103993, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38901380

RESUMO

RESEARCH QUESTION: Is acrosin activity related to cumulative live birth rate (CLBR) over 1 year after IVF, intracytoplasmic sperm injection (ICSI) treatment or both? DESIGN: Retrospective monocentric cohort study of 5704 couples who started IVF/ICSI treatments between 2016 and 2021. Acrosin activity was determined by a modified Kennedy method using a commercial kit. Patients were divided into two groups according to their acrosin activity: below 25 µIU/106 spermatozoa; and an acrosin activity 25 µIU/106 spermatozoa or above. Primary outcome was the CLBR, defined as an ongoing pregnancy leading to live birth that had arisen from all embryo transfers carried out within 1 year after the first ovum retrieval. Both conservative and optimistic methods were used for estimating CLBRs. RESULTS: The CLBRs of patients with an acrosin activity below 25 µIU/106 spermatozoa were found to be significantly lower than those of patients with an acrosin activity 25 µIU/106 spermatozoa or above by conservative (48.5% versus 55.4%, P = 0.02) and optimistic (63.7% versus 70.3%, P = 0.047) methods after adjusting for confounders. When acrosin activity was regarded as a continuous variable, significant negative relationships between acrosin activity and CLBR were identified in subgroups: young couples (men and women aged younger than 30 years) and couples from whom no more than 10 eggs were retrieved. CONCLUSION: Low acrosin activity levels were correlated with decreasing CLBRs over 1 year. These findings suggest that acrosin activity can be used as a predictor for CLBRs before starting IVF/ICSI treatment to enhance the effectiveness of counselling.

2.
Transl Cancer Res ; 13(4): 2026-2042, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38737700

RESUMO

Background and Objective: Lysyl oxidase-like protein 4 (LOXL4) is a secreted copper-dependent amine oxidase involved in the assembly and maintenance of extracellular matrix (ECM), playing a critical role in ECM formation and repair. Tumor-stroma interactions and ECM dysregulation are closely associated with the mechanisms underlying tumor initiation and progression. LOXL4 is the latest identified member of the lysyl oxidase (LOX) protein family. Currently, there is limited and controversial research on the role of LOXL4 in human malignancies. Its specific regulatory pathways, mechanisms, and roles in the occurrence, development, and treatment of malignancies remain incompletely understood. This article aims to illustrate the primary protein structure and the function of LOXL4 protein, and the relationship between LOXL4 protein and the occurrence and development of human malignant tumors to provide a reference for further clinical research. Methods: We searched the English literature on LOXL4 in the occurrence and development of various malignant tumors in PubMed and Web of Science. The search keywords include "cancer" "LOXL4" "malignant tumor" "tumorigenesis and development", etc. Key Content and Findings: LOXL4 is up-regulated in human gastric cancer, breast cancer, ovarian cancer, head and neck squamous cell carcinoma, esophageal carcinoma and colorectal cancer, but down-regulated in human bladder cancer and lung cancer and inhibits tumor growth. There are two conflicting reports of both upregulation and downregulation in hepatocellular carcinoma, suggesting that LOXL4 has a bidirectional effect of promoting or inhibiting cancer in different types of human malignant tumors. We further explore the application prospect of LOXL4 protein in the study of malignant tumors, laying a theoretical foundation for the clinical diagnosis, treatment and screening of prognostic markers of malignant tumors. Conclusions: LOXL4 exerts a bidirectional regulatory role, either inhibiting or promoting tumors depending on the type of cancer. We still need more research to further confirm the molecular mechanism of LOXL4 in cancer progression.

3.
JAMA Netw Open ; 7(3): e243812, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38546641

RESUMO

Importance: Whether anti-Helicobacter pylori treatment can provide survival benefits for patients with gastric cancer who are diagnosed with H pylori infection is an area with limited research. Objective: To explore the potential survival benefits of anti-H pylori treatment after radical gastrectomy in patients with gastric cancer and presurgical confirmation of H pylori infection. Design, Setting, and Participants: This retrospective cohort study was conducted using data from patients with gastric cancer treated between January 1, 2010, and December 31, 2018, and followed up for outcome ascertainment until May 19, 2021. Propensity score matching was performed in patients treated with or without anti-H pylori treatment. This study involved a single institute in a comprehensive cancer treatment and research center located in Guangzhou, Guangdong Province, China. The study included patients with gastric or esophagogastric junction adenocarcinoma who underwent curative gastrectomy with D2 lymphadenectomy and tested positive for H pylori infection. Data were analyzed from March to June 2023. Exposure: Anti-H pylori treatment, which primarily includes triple therapy regimens consisting of amoxicillin, clarithromycin, and omeprazole for 14 days. Main Outcomes and Measures: Clinical outcomes, including overall survival (OS) and disease-free survival (DFS), were analyzed by Kaplan-Meier method, log-rank test, and Cox proportional hazards regression model. Subgroup analysis based on crucial clinical information was also conducted. Results: All 1293 patients (median [IQR] age, 59 [50-65] years; 860 [66.5%] male) were divided into 2 groups, with 125 patients in the anti-H pylori treatment group and 1168 patients in the non-anti-H pylori treatment group based on whether they received anti-H pylori treatment during the perioperative period and the follow-up. Survival analysis showed that the 5-year OS rates were 94.1% (95% CI, 89.3%-99.2%) in the anti-H pylori group and 73.8% (95% CI, 70.7%-77.0%) in the non-anti-H pylori group, and the hazard ratio (HR) of these 2 groups was 0.33 (95% CI, 0.18-0.60; P < .001). The survival benefit remained after propensity score matching (HR, 0.50; 95% CI, 0.26-0.99; P = .048). Multivariable analysis for OS and DFS further showed the survival benefit of anti-H pylori treatment, with HRs of 0.38 (95% CI, 0.17-0.87; P = .02) and 0.48 (95% CI, 0.28-0.83; P = .008), respectively. Among patients with TNM stage II/III disease who received adjuvant chemotherapy, anti-H pylori treatment was associated with survival benefits (OS: HR, 0.49; 95% CI, 0.24-0.99; P = .046), whereas among those who did not receive adjuvant chemotherapy, anti-H pylori treatment was not associated with survival benefits (OS: HR, 0.29; 95% CI, 0.04-2.08; P = .22). Conclusions and Relevance: This cohort study indicates that anti-H pylori treatment may be associated with improved survival in patients with gastric cancer who have H pylori infections. The study reinforces the importance of including H pylori screening and treatment in the surgical treatment of these patients.


Assuntos
Neoplasias Gástricas , Humanos , Masculino , Pessoa de Meia-Idade , Feminino , Neoplasias Gástricas/cirurgia , Estudos de Coortes , Estudos Retrospectivos , Gastrectomia , Academias e Institutos
4.
World J Gastroenterol ; 30(6): 607-609, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38463024

RESUMO

The present letter to the editor is related to the study titled 'Angiotensin-converting enzyme 2 improves liver fibrosis in mice by regulating autophagy of hepatic stellate cells'. Angiotensin-converting enzyme 2 can alleviate liver fibrosis by regulating autophagy of hepatic stellate cells and affecting the renin-angiotensin system.


Assuntos
Peptidil Dipeptidase A , Sistema Renina-Angiotensina , Animais , Camundongos , Angiotensina II/metabolismo , Enzima de Conversão de Angiotensina 2 , Fibrose , Células Estreladas do Fígado/metabolismo , Cirrose Hepática , Peptidil Dipeptidase A/metabolismo
5.
Nat Commun ; 15(1): 1402, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38365867

RESUMO

High or medium- entropy alloys (HEAs/MEAs) are multi-principal element alloys with equal atomic elemental composition, some of which have shown record-breaking mechanical performance. However, the link between short-range order (SRO) and the exceptional mechanical properties of these alloys has remained elusive. The local destruction of SRO by dislocation glide has been predicted to lead to a rejuvenated state with increased entropy and free energy, creating softer zones within the matrix and planar fault boundaries that enhance the ductility, but this has not been verified. Here, we integrate in situ nanomechanical testing with energy-filtered four-dimensional scanning transmission electron microscopy (4D-STEM) and directly observe the rejuvenation during cyclic mechanical loading in single crystal CrCoNi at room temperature. Surprisingly, stacking faults (SFs) and twin boundaries (TBs) are reversible in initial cycles but become irreversible after a thousand cycles, indicating SF energy reduction and rejuvenation. Molecular dynamics (MD) simulation further reveals that the local breakdown of SRO in the MEA triggers these SF reversibility changes. As a result, the deformation features in HEAs/MEAs remain planar and highly localized to the rejuvenated planes, leading to the superior damage tolerance characteristic in this class of alloys.

6.
J Assist Reprod Genet ; 41(1): 3-13, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37878219

RESUMO

PURPOSE: Recurrent implantation failure (RIF) affects up to 10% of in vitro fertilization (IVF) patients worldwide. However, the pathogenesis of RIF remains unclear. This study was aimed at identifying hub transcription factors (TFs) of RIF in bioinformatics approaches. METHODS: The GSE111974 (mRNA), GSE71332 (miRNA), and GSE103465 (mRNA) datasets were downloaded from the Gene Expression Omnibus database from human endometrial tissue using R version 4.2.1 and used to identify differentially expressed TFs (DETFs), differentially expressed miRNAs, and differentially expressed genes for RIF, respectively. DETFs were subjected to functional enrichment analysis and the protein-protein interaction network analysis using the Search Tool for the Retrieval of Interacting Genes (version 11.5) database. Hub TFs were identified using the cytoHubb plug-in, after which a hub TF-miRNA-mRNA network was constructed using Cytoscape v3.8.2. RESULTS: Fifty-seven DETFs were identified, in which Gene Ontology analysis revealed to be mainly involved in the regulation of transcription. Kyoto Encyclopedia of Genes and Genomes pathway analysis suggested that DETFs were enriched in transcriptional misregulation in cancer, aldosterone synthesis and secretion, AMPK signaling pathway, and cGMP-PKG signaling pathway. EOMES, NKX2-1, and POU5F1 were identified as hub TFs, and a hub TF-miRNA-mRNA regulatory network was constructed using these three hub TFs, four miRNAs, and four genes. CONCLUSION: Collectively, we identified three promising molecular biomarkers for the diagnosis of RIF, which may further be potential therapeutic targets. This study provides novel insights into the molecular mechanisms underlying RIF. However, further experiments are required to verify these results.


Assuntos
MicroRNAs , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Redes Reguladoras de Genes/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica/genética , Biologia Computacional/métodos
7.
Ann Surg Oncol ; 30(13): 8561-8571, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37718336

RESUMO

BACKGROUND: The effect of a single tumor marker on the prognosis of gastric cancer patients is not ideal. This study explored a novel prognostic assessment method for gastric cancer (GC) patients using a combination of three important tumor markers (CEA, CA72-4, and CA19-9). METHOD: Data from 1966 GC patients who underwent curative gastrectomy at Sun Yat-Sen University Cancer Center (Guangzhou, China) were included. Hazard ratios (HR) for all factors for overall survival (OS) were analyzed by Cox regression. A nomogram and calibration curve were used to establish the survival prediction model. The prediction accuracy was evaluated with the concordance index (C-index). RESULTS: All patients were divided into four groups (C0-C3) according to the number of elevated tumor markers. The 5-year OS rates of the patients in preoperative groups C0-C3 were 83.8% (81.3-86.4%), 72.8% (68.5-77.4%), 58.9% (50.4-68.9%), and 18.5% (4.0-33.0%), respectively, and those in postoperative groups C0-C3 were 82.1% (79.4-84.8%), 76.1% (72.2-80.3%), 57.6% (48.4-68.5%), and 16.8% (5.1-28.5%), respectively, with significant differences between each C0-C3 subgroup in both preoperative and postoperative cohorts. Multivariate analysis showed that preoperative (HR: 6.001, 95% CI: 3.523-10.221) and postoperative (HR: 8.149, 95% CI: 4.962-13.528) elevated tumor markers were independent risk factors for GC patients. The C-index for the combined use of tumor markers was 0.65-0.66, which was higher than that for using a single tumor marker (0.53-0.56). CONCLUSION: The combined use of tumor markers significantly improved the prognostic value compared with using a single tumor marker. The survival prediction model including the combined tumor markers was accurate and effective.


Assuntos
Biomarcadores Tumorais , Neoplasias Gástricas , Humanos , Prognóstico , Neoplasias Gástricas/patologia , Antígeno Carcinoembrionário , Estudos Retrospectivos
9.
Microsc Microanal ; 29(5): 1628-1638, 2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37584510

RESUMO

We demonstrate a new focused ion beam sample preparation method for atom probe tomography. The key aspect of the new method is that we use a neon ion beam for the final tip-shaping after conventional annulus milling using gallium ions. This dual-ion approach combines the benefits of the faster milling capability of the higher current gallium ion beam with the chemically inert and higher precision milling capability of the noble gas neon ion beam. Using a titanium-aluminum alloy and a layered aluminum/aluminum-oxide tunnel junction sample as test cases, we show that atom probe tips prepared using the combined gallium and neon ion approach are free from the gallium contamination that typically frustrates composition analysis of these materials due to implantation, diffusion, and embrittlement effects. We propose that by using a focused ion beam from a noble gas species, such as the neon ions demonstrated here, atom probe tomography can be more reliably performed on a larger range of materials than is currently possible using conventional techniques.

10.
Biomedicines ; 11(7)2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37509642

RESUMO

BACKGROUND: Recently, many studies have explored the relationship between the expression of programmed death ligand 1 (PD-L1) and prognosis in gastric cancer, but there is still controversy. Additionally, few studies have specifically investigated the expression of PD-L1 in patients with peritoneal metastasis. METHODS: Immunohistochemistry was used to analyze the expression of PD-L1 in gastric cancer patients with peritoneal metastasis. The combined positive score (CPS) was calculated to evaluate the expression of PD-L1, and the clinicopathological data were analyzed to explore prognostic significance. RESULTS: In total, 147 gastric cancer patients with peritoneal metastasis were enrolled. The negative PD-L1 expression was defined as a CPS < 1, and high PD-L1 expression was defined as a CPS ≥ 10. PD-L1 expression with CPS ≥ 1 and CPS-negative was detected in 67 (45.58%) and 80 (54.42%) patients, respectively. High PD-L1 expression at PD-L1 CPS ≥ 10 was detected in 21(14.29%) patients. The median overall survival (OS) was 18.53 months in the CPS < 10 group and 27.00 months in the CPS ≥ 10 group; the OS difference between the two groups was significant (p = 0.015). Multivariate analysis demonstrated that a poor Eastern Cooperative Oncology Group performance score (ECOG PS) (p = 0.002) and severe peritoneal metastasis (p = 0.033) were significantly associated with poor survival, while palliative chemotherapy (p = 0.002) and high PD-L1 expression (p = 0.008) were independent and significantly favorable prognostic factors. CONCLUSIONS: Our study demonstrated that PD-L1 expression was widely presented in gastric cancer patients with peritoneal metastasis, while a CPS no less than 10 predicted better prognosis.

11.
J Natl Cancer Inst ; 115(9): 1085-1091, 2023 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-37389446

RESUMO

BACKGROUND: Relapse-free survival (RFS) has been considered a primary endpoint to assess the effects of immunotherapy in the adjuvant setting among patients with early-stage disease. However, it is not clear whether RFS is a valid surrogate endpoint for overall survival (OS) in this clinical context. METHODS: Phase II or III clinical trials of adjuvant immunotherapy that reported hazard ratios on OS and RFS were identified. We used a weighted regression analysis at the arm and trial levels to assess the efficacy of RFS as a surrogate for OS, quantified by the weighted coefficient of determination (R2). Strong correlations (R2 ≥ 0.7) at the arm and trial levels indicated valid surrogacy. The surrogate threshold effect was also evaluated. RESULTS: Fifteen high-quality randomized clinical trials involving 13 715 patients were included. At the arm level, moderate and strong associations were observed between RFS2-year and OS3-year (R2 = 0.58, 95% confidence interval [CI] = 0.25 to 0.92) and RFS3-year and OS5-year (R2 = 0.72, 95% CI = 0.38 to 1.00), respectively. At the trial level, a moderate association was observed between effect of treatment on RFS and OS (R2 = 0.63, 95% CI = 0.33 to 0.94). The surrogate threshold effect for RFS was 0.86. Consistent results were confirmed in several sensitivity analyses based on different trial phases, experimental arms, cancer types, and treatment strategies. CONCLUSIONS: Our meta-analysis failed to find a clinically strong association between RFS and OS in randomized clinical trials of adjuvant immunotherapy. Our findings challenge the use of RFS as the primary efficacy endpoint and suggest the use of OS in this clinical context.


Assuntos
Imunoterapia , Humanos , Modelos de Riscos Proporcionais , Biomarcadores/análise , Análise de Regressão , Intervalo Livre de Doença , Ensaios Clínicos Controlados Aleatórios como Assunto
12.
J Obstet Gynaecol Res ; 49(8): 2093-2101, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37277920

RESUMO

AIM: Vitamin D3 has been implicated in multiple reproductive events, whereas the effect of its bioactive metabolite 1α, 25 dihydroxyvitamin D3 (1,25(OH) 2 D3 ) on transcriptome profile of the placenta is unclear. The aim of this article is to determine transcriptome-wide profile caused by 1,25(OH) 2 D3 in human placental trophoblast cells. METHODS: We performed RNA sequencing after stimulation of HTR-8/SVneo cells with 0.1, 1, 10, and 100 nM 1,25(OH)2 D3 for 24 h, identified differentially expressed genes by edgeR package (version 3.38.4), and analyzed Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways by webtool Metascape. Also, common genes and specific genes in different concentrations of 1,25(OH) 2 D3 were identified. RESULTS: There were 180, 158, 161, and 174 differentially expressed genes after 0.1, 1, 10, and 100 nM 1,25(OH) 2 D3 stimulation, respectively. KEGG pathway analysis displayed that "lipid and atherosclerosis" were significantly enriched at 0.1 and 1 nM 1,25(OH)2 D3 , while "cytokine-cytokine receptor interaction," "TGF-beta signaling pathway" and "hippo signaling pathway" were significantly enriched in 1, 10, and 100 nM 1,25(OH)2 D3 . CYP24A1 was a significantly expressed common gene. UCP3 was significantly expressed in low concentrations and might affect energy metabolism. TCF24, EIF3CL, ABCD2, EPHA7, CRLF1, and SECTM1 were specific genes at physiological concentration. Similarly, SPDYE1, IQUB, IL18R1, and ZNF713 were considered as specific genes at supraphysiological concentration. CONCLUSIONS: 1,25(OH)2 D3 mainly affected the expression of CYP24A1 gene in HTR-8/SVneo cells. Specific genes accounted for the majority of differentially expressed genes at different concentrations. However, their functions need to be further confirmed.


Assuntos
Placenta , Transcriptoma , Feminino , Humanos , Gravidez , Vitamina D3 24-Hidroxilase/metabolismo , Placenta/metabolismo , Vitamina D , Colecalciferol
13.
Sci Adv ; 9(18): eadf8602, 2023 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-37146144

RESUMO

The extraordinary work hardening ability and fracture toughness of the face-centered cubic (fcc) high-entropy alloys render them ideal candidates for many structural applications. Here, the deformation and failure mechanisms of an equiatomic CrCoNi medium-entropyalloy (MEA) were investigated by powerful laser-driven shock experiments. Multiscale characterization demonstrates that profuse planar defects including stacking faults, nanotwins, and hexagonal nanolamella were generated during shock compression, forming a three-dimensional network. During shock release, the MEA fractured by strong tensile deformation and numerous voids was observed in the vicinity of the fracture plane. High defect populations, nanorecrystallization, and amorphization were found adjacent to these areas of localized deformation. Molecular dynamics simulations corroborate the experimental results and suggest that deformation-induced defects formed before void nucleation govern the geometry of void growth and delay their coalescence. Our results indicate that the CrCoNi-based alloys are impact resistant, damage tolerant, and potentially suitable in applications under extreme conditions.

14.
Nat Commun ; 14(1): 404, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36725856

RESUMO

Interstitial oxygen embrittles titanium, particularly at cryogenic temperatures, which necessitates a stringent control of oxygen content in fabricating titanium and its alloys. Here, we propose a structural strategy, via grain refinement, to alleviate this problem. Compared to a coarse-grained counterpart that is extremely brittle at 77 K, the uniform elongation of an ultrafine-grained (UFG) microstructure (grain size ~ 2.0 µm) in Ti-0.3wt.%O is successfully increased by an order of magnitude, maintaining an ultrahigh yield strength inherent to the UFG microstructure. This unique strength-ductility synergy in UFG Ti-0.3wt.%O is achieved via the combined effects of diluted grain boundary segregation of oxygen that helps to improve the grain boundary cohesive energy and enhanced dislocation activities that contribute to the excellent strain hardening ability. The present strategy will not only boost the potential applications of high strength Ti-O alloys at low temperatures, but can also be applied to other alloy systems, where interstitial solution hardening results into an undesirable loss of ductility.

15.
Science ; 378(6623): 978-983, 2022 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-36454850

RESUMO

CrCoNi-based medium- and high-entropy alloys display outstanding damage tolerance, especially at cryogenic temperatures. In this study, we examined the fracture toughness values of the equiatomic CrCoNi and CrMnFeCoNi alloys at 20 kelvin (K). We found exceptionally high crack-initiation fracture toughnesses of 262 and 459 megapascal-meters½ (MPa·m½) for CrMnFeCoNi and CrCoNi, respectively; CrCoNi displayed a crack-growth toughness exceeding 540 MPa·m½ after 2.25 millimeters of stable cracking. Crack-tip deformation structures at 20 K are quite distinct from those at higher temperatures. They involve nucleation and restricted growth of stacking faults, fine nanotwins, and transformed epsilon martensite, with coherent interfaces that can promote both arrest and transmission of dislocations to generate strength and ductility. We believe that these alloys develop fracture resistance through a progressive synergy of deformation mechanisms, dislocation glide, stacking-fault formation, nanotwinning, and phase transformation, which act in concert to prolong strain hardening that simultaneously elevates strength and ductility, leading to exceptional toughness.

16.
Small ; 18(41): e2203310, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36084232

RESUMO

The rapid advancement of transmission electron microscopy has resulted in revolutions in a variety of fields, including physics, chemistry, and materials science. With single-atom resolution, 3D information of each atom in nanoparticles is revealed, while 4D electron tomography is shown to capture the atomic structural kinetics in metal nanoparticles after phase transformation. Quantitative measurements of physical and chemical properties such as chemical coordination, defects, dislocation, and local strain have been made. However, due to the incompatibility of high dose rate with other ultrathin morphologies, such as nanowires, atomic electron tomography has been primarily limited to quasi-spherical nanoparticles. Herein, the 3D atomic structure of a complex core-shell nanowire composed of an ultrathin Boerdijk-Coxeter-Bernal (BCB) core nanowire and a noble metal thin layer shell deposited on the BCB nanowire surface is discovered. Furthermore, it is demonstrated that a new superthin noble metal layer deposition on an ultrathin BCB nanowire could mitigate electron beam damage using an in situ transmission electron microscope and atomic resolution electron tomography. The colloidal coating method developed for electron tomography can be broadly applied to protect the ultrathin nanomaterials from electron beam damage, benefiting both the advanced material characterizations and enabling fundamental in situ mechanistic studies.


Assuntos
Nanopartículas Metálicas , Nanofios , Tomografia com Microscopia Eletrônica , Elétrons , Nanopartículas Metálicas/química , Metais/química , Microscopia Eletrônica de Transmissão , Nanofios/química
17.
Science ; 376(6594): eabo5247, 2022 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-35549435

RESUMO

We address the three main points of Guo et al. They claim that we should have used the engineering stress versus engineering strain curves to infer the mechanical properties of our nanotwinned titanium, question our sample design on the basis of a finite-element analysis, and doubt the immobility of some preexisting grain/twin boundaries in our electron backscatter diffraction micrographs. We find their analysis to be groundless and to contain many inconsistencies.

18.
J Neurosurg ; : 1-11, 2022 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-35171834

RESUMO

OBJECTIVE: Treatment outcomes following initial transsphenoidal surgery (TSS) for acromegaly are erratic. Identifying outcome patterns can assist in informing patients about possible treatment outcomes and planning for individualized adjuvant treatments in advance. In this study, the authors aimed to investigate the immediate and long-term endocrine remission rates following initial TSS for acromegaly, identify clinical determinants of treatment outcomes, and explore outcome patterns during a long-term follow-up and the pattern-specific patient features. METHODS: This prospective, single-center, longitudinal cohort study enrolled patients with acromegaly who underwent TSS in the period from 2015 to 2018 at the authors' institution. Immediate remission, assessed on the 2nd postoperative morning, and long-term remission, assessed at least 18 months after TSS, were evaluated according to the strict 2010 consensus criteria (random growth hormone [GH] < 1 ng/ml or GH nadir < 0.4 ng/ml after oral glucose tolerance test, and age- and sex-normalized insulin-like growth factor 1). Univariate and bivariate regression analyses were used to identify determinants of remission. RESULTS: A total of 659 patients with acromegaly (average age 42 years, 44% males) underwent TSS for pituitary adenomas (macroadenomas, 85%; invasive tumors, 35%) and were followed up during a median of 51 months. Immediate and long-term remission rates after initial TSS were 37% and 69%, respectively. Older age at diagnosis (OR 1.7), male sex (OR 1.6), smaller tumors (OR 2.0), noninvasive tumors (OR 4.8), and tumors positive for follicle-stimulating hormone/luteinizing hormone (OR 1.5) were predictors of immediate surgical remission. In addition to the above predictors, lower preoperative GH (OR 2.4), absence of preoperative central hypothyroidism (OR 2.6), and endoscopic TSS (OR 10.6) were predictors of long-term remission. Regression analyses revealed that endoscopic TSS (OR 2.8, 95% CI 1.524-5.291, p = 0.001), absence of cavernous sinus invasion (OR 4.1, 95% CI 2.522-6.613, p < 0.001), older age (OR 1.03, 95% CI 1.006-1.048, p = 0.013), and male sex (OR 2.0, 95% CI 1.224-3.247, p = 0.006) were independent determinants of long-term remission. Five outcome patterns were identified based on the changes in hormonal results during follow-up, including continuous remission (34%), refractory acromegaly (28%), delayed remission (21%), remission after adjuvant therapy (14%), and recurrence after initial remission (3%). The clinical characteristics of each subgroup were identified. CONCLUSIONS: Cavernous sinus invasion, age at diagnosis, and sex are the best determinants of immediate and long-term remission after initial TSS for acromegaly. Endoscopic TSS predicts a higher long-term remission rate than that with microscopic TSS. The authors identified five outcome patterns in acromegaly and group-specific patient characteristics for clinical decision-making.

19.
Afr J Reprod Health ; 26(5): 107-119, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-37585103

RESUMO

In recent years, contraceptive medication has been widely used for birth control. It is worth noting that contraceptive medication from botanical source has great potential for clinical use. Yunnan is the province with the most species of plants in China and is known as the "plant kingdom". This study aims to archive herbal remedies traditionally used as antifertility remedies in Dali District, Yunnan Province, P. R. China. The survey was conducted from February 2011 to September 2016 in the population distributed in Dali and the surrounding counties. The data were collected from three groups of practitioners within the study area: therapists using traditional medicines (n = 104), aboriginal families (n = 37), and herbalists in commercial stalls (n = 12), and a total number of 117 plant species were recorded. Among the 117 plant species, 104 of which have been authenticated by a plant taxonomist from the Dali Herbarium. These plants were classified into 98 genera and 54 families, including Leguminosae (12 species), Liliaceae (7 species), Cucurbitaceae, Rosaceae and Rutaceae (5 species, respectively), Malvaceae, Compositae and Euphorbiaceae (4 species, respectively). Our data provides an in-depth delineation of the contraceptive plants used in Dali, which serve as valuable information for the practitioners of traditional Chinese medicine in contraceptive use. In addition, these data also hint that plants from different genus contain contraceptive components, which should be avoided by pregnant women. Future studies are required to identify the active contraceptive components, assess the toxicology, and elucidate the pharmacological mechanism of action.


Assuntos
Plantas Medicinais , Gravidez , Feminino , Humanos , Fitoterapia , China , Etnobotânica , Anticoncepcionais
20.
Nat Commun ; 12(1): 6158, 2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-34697309

RESUMO

Individually, increasing the concentration of either oxygen or aluminum has a deleterious effect on the ductility of titanium alloys. For example, extremely small amounts of interstitial oxygen can severely deteriorate the tensile ductility of titanium, particularly at cryogenic temperatures. Likewise, substitutional aluminum will decrease the ductility of titanium at low-oxygen concentrations. Here, we demonstrate that, counter-intuitively, significant additions of both Al and O substantially improves both strength and ductility, with a 6-fold increase in ductility for a Ti-6Al-0.3 O alloy as compared to a Ti-0.3 O alloy. The Al and O solutes act together to increase and sustain a high strain-hardening rate by modifying the planar slip that predominates into a delocalized, three-dimensional dislocation pattern. The mechanism can be attributed to decreasing stacking fault energy by Al, modification of the "shuffle" mechanism of oxygen-dislocation interaction by the repulsive Al-O interaction in Ti, and micro-segregation of Al and O by the same cause.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...