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2.
Zhonghua Wei Chang Wai Ke Za Zhi ; 25(8): 716-725, 2022 Aug 25.
Artículo en Chino | MEDLINE | ID: mdl-35970806

RESUMEN

Objective: To Summarize the safety, clinical outcome and technical evolution of laparoscopic gastric cancer surgery. Methods: A retrospective cohort study was carried out. Clinical data of 3012 patients who underwent laparoscopic radical gastrectomy for gastric cancer from January 2010 to March 2022 at Department of General Surgery, the First Affiliated Hospital of Nanjing Medical University were retrospectively collected and analyzed. Case inclusion criteria were gastric malignancies confirmed by pathology, without distant metastasis by examination before operation and exploration during operation, patients undergoing laparoscopic radical gastrectomy, intact function of important organs and with complete data. Exclusion criteria were patients who underwent emergency gastric cancer resection due to gastric bleeding, perforation or obstruction, etc., tumor found to invade adjacent organs such as pancreas or transverse colon during the operation, conversion to open surgery during the operation, those who had other malignant tumors (except thyroid cancer) within 5 years, and those had severe cardiopulmonary, liver, or kidney insufficiency before surgery. Outcomes included: (1) baseline information of patients; (2) trend of the quantity of laparoscopic radical gastrectomy year by year; (3) evolution of the mode of digestive tract reconstruction; (4) periopertive outcome short-term complication was defined as complication occurring within 30 days after operation and classified accordiny to the clavien-Dindo criteria; and (5) 5-year overall survival. SPSS software was used for statistical analysis. Continuous variables that obeyed the normal distribution were expressed in the form of Mean±SD. Days of hospital stay that did not follow a normal distribution were expressed as median (Q1,Q3), and the Mann-Whiney U test was used for comparison. Discrete variables were expressed as cases (%), and chi-square test or rank sum test was used for comparison between groups. Linear regression analysis was used to analyze the relationship between the amount of surgery and the year of surgery. Kaplan-Meier method and log-rank test were used for survival analysis. Two-tailed P<0.05 was considered as statistically significant. Results: Among the 3012 cases, 2114 were male and 898 were female. The patients' average age at surgery was (61.1±10.7) years old. According to the number of cumulative cases, the patients were divided into three groups: early, intermediate and late, with 1004 patients in each group. The early group consisted of patients undergoing operation from January 2010 to October 2018, the intermediate group consisted of patients undergoing operation from October 2018 to January 2021, and the late group consisted of patients undergoing operation from January 2021 to March 2022. (1) General information: There were 691 (68.8%), 699 (69.6%) and 724 (72.1%) male patients in early, intermediate and late groups respectively; the average age increased from 56.6 years in 2010 to 62.8 years in March 2022. As for the tumor stage T1, T2, T3, T4, there were 49.0%, 14.4%, 23.9% and 12.6% in the early group; 47.5%, 12.9%, 26.9% and 12.6% in the intermediate group; 39.7%, 14.6%, 30.0%, and 15.6% in the late group, respectively. Patients with N0, N1, N2, N3a, N3b stage were 56.8%, 13.7%, 13.4%, 11.0%, and 5.0% in the early group; 55.7%, 12.9%, 12.8%, 11.6%, and 6.9% in the intermediate group; 51.0%, 16.1%, 12.8%, 12.5%, and 7.5% in the late group, respectively. (2) Year-by-year change in the number of gastric cancer operations: From 19 cases per year in 2010 to 786 per year in 2021, the annual number of gastric cancer operations was proportional to the year of operation (y=47.505x, R2=0.67). The proportion of patients with stage I disease showed a fluctuating downward trend over time, while the proportion of patients with stage III disease increased slightly, accounting for 34% until March 2022. (3) Evolution of digestive tract reconstruction methods: Except in 2010, the digestive tract reconstruction method of distal gastrectomy focused on Billroth-II+Braun anastomosis among patients undergoing laparoscopic gastric cancer surgery in other years, whose proportion had gradually increased from less than 20% in 2016 to about 70% after 2021; the gastrointestinal reconstruction methods after total gastrectomy had gradually increased in π anastomosis and overlap anastomosis since 2016, of which π anastomosis reached about 65% in 2019, and overlap anastomosis reached almost 30% in 2020; the anastomosis methods after proximal gastrectomy had been mainly double-channel anastomosis (54%) and esophagogastric anastomosis (30%) since 2016, and double-channel anastomosis accounted for up to 70% in 2019. (4) Operation time: The operation time of early, intermediate and late group was (193.3±49.8) min, (186.9±44.3) min and (206.7±51.4) min respectively. Intermediate group was significantly shorter than early group (t=3.005, P=0.003), while late group was significantly longer than early group (t=5.875, P<0.001) and intermediate group (t=9.180, P<0.001). (5) Postoperative hospital stay: The median length of hospital stay for gastric cancer patients in early, intermediate and late groups was 9 (8, 11) d, 8 (7, 10) d, and 8 (7.5, 10) d respectively. The postoperative hospital stay of intermediate group and late group was significantly shorter than that of early group (Z=-12.467, Z=-5.981, both P<0.001), but there was no significant difference between intermediate group and late group (Z=0.415,P=0.678). (6) Postoperative complication: The morbidity of short-term complication in early, intermediate and late group was 20.4% (205/1004), 16.2% (163/1004), and 16.2% (162/1004) respectively, and above morbidity of intermediate group and late group was significantly lower than that of early group (χ2=5.869, P=0.015; χ2=6.165, P=0.013), while there was no significant difference between intermediate group and late group (χ2=0.004,P=0.952). The morbidity of short-term complication of grade IIIor higher was 8.0% (80/1004), 7.6% (76/1004), and 4.9% (49/1004) in early, intermediate and late group respectively, and above morbidity of late group was significantly lower than that of early and intermediate group (χ2=7.965, P=0.005; χ2=6.219,P=0.013), while there was no significant difference between intermediate group and early group (χ2=0.111,P=0.739). (7) Survival analysis: The follow-up deadline for survival data was December 31, 2021, and the median follow-up time was 29.5 months. The overall 5-year survival rate of all the patients was 74.7%. The 5-year survival rates of stage I, II and III patients were 92.0%, 77.2%, and 40.3% respectively and 5-year survival rates of patients with stage IA, IB, IIA, IIB, IIIA, IIIB and IIIC were 93.2%, 87.8%, 81.1%, 72.7%, 46.2%, 37.1%, and 34.0% respectively. Conclusions: The number of laparoscopic gastric cancer operation in our center is increasing year by year. With the maturity of laparoscopic technology, the morbidity of complication in laparoscopic gastric cancer surgery is decreasing.


Asunto(s)
Gastrectomía , Laparoscopía , Neoplasias Gástricas , Anciano , Análisis de Datos , Femenino , Gastrectomía/efectos adversos , Gastrectomía/métodos , Humanos , Laparoscopía/efectos adversos , Laparoscopía/métodos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Neoplasias Gástricas/cirugía , Resultado del Tratamiento
5.
Zhonghua Yu Fang Yi Xue Za Zhi ; 52(12): 1234-1238, 2018 Dec 06.
Artículo en Chino | MEDLINE | ID: mdl-30522222

RESUMEN

Objective: To investigate the related factors of unprotected sexual behaviors among male students who have sex with men in Beijing. Methods: Male students who have sex with men were recruited from May 2018 to July 2018 at two voluntary counseling and testing (VCT) clinics in Beijing by convenient sampling method. Information being collected during in-depth personal interviews with a semi-structured outline included ways to seek sexual partners, sexual partners characteristics, attitude of condom use, incidence and causes of unprotected sexual behaviors, rush poppers and alcohol use. The text information was summarized and analyzed by Nvivo 11.0 software. Results: A total of 35 male students who have sex with men were recruited and interviewed, the median of age was 22 years old (P(25)-P(75): 21-24 years old). We found that incomprehensive knowledge of condom use, low risk perception of non-anal sexual behaviors, rush poppers and alcohol use were risk factors of unprotected sexual behaviors on individual level. Besides, sex with regular sex partners, partners who were much older or not from campus, and insertive partners are more likely to be unprotected. Furthermore, refusal of condom use by sexual partners and low self-efficacy of decision-making on condom use were the main reasons for unprotected sexual behaviors among male student who have sex with men. Conclusion: Lack of condom use knowledge, low risk perception of non-anal sexual behaviors and insufficient ability to refuse non-condom requirements for regular sex partners, partners who were much older or not from campus, and insertive partners are related factors of unprotected sexual behaviors among male students who have sex with men.


Asunto(s)
Homosexualidad Masculina/psicología , Estudiantes/psicología , Sexo Inseguro/psicología , Beijing , Homosexualidad Masculina/estadística & datos numéricos , Humanos , Masculino , Investigación Cualitativa , Estudiantes/estadística & datos numéricos , Adulto Joven
6.
Opt Express ; 26(14): 18794-18802, 2018 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-30114051

RESUMEN

As a fast-developing technique for in situ multi-element analysis method, laser induced breakdown spectroscopy - LIBS is, however, developing slowly on liquid analysis due to some technical difficulties. We propose a new method, namely capillary mode, to quantify the concentrations of the elements in solution using LIBS. A Nd:YAG laser with repetition of 10 Hz were used to analyze the solution of Na2CrO4 and no any sample preparation in measurements. The experimental results show that the splashing of liquid induced by laser pulses is decreased significantly and the pollution of mirrors is avoided effectively using liquid capillary mode. The results of quantitative analysis for liquid are also improved than other method. The calibration curves of Cr and Na are well characterized by straight lines and the regression coefficient values of the linear fit are better than 0.998. The limits of detection (LODs) of Cr and Na are determined to be 28.9 mg/L and 1.0 mg/L in this work, respectively. The experimental results show that the liquid capillary mode provides a more practical and very simple approach to improve accuracy of quantitative element analysis in liquids by LIBS technique.

7.
Sci Rep ; 8(1): 9496, 2018 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-29934506

RESUMEN

In this study, an in situ ß-Ti-Nb composites reinforced with TiC particles with an ultrafine grain size were fabricated using a powder metallurgical (PM) method. The microstructures and mechanical properties of the composites were characterized using X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and compression tests. TiC particles were formed in the ball-milled powders after annealing at 600 °C due to a chemical reaction between stearic acid and titanium. Using high-pressure sintering (HPS) on an apparatus with six tungsten carbide anvils, a fully dense ß-Ti-Nb composite reinforced with fine in situ TiC particles was obtained. The TiC particles exhibit particle sizes of ~500 nm, uniformly distributed in the composite matrix, which had grain sizes of ~600 nm. Thus, the TiC-ß-Ti-Nb composite show very high compression yield strength and relatively high plasticity contributed by grain refinement and TiC particles strengthening. The composite with 45 vol.% TiC exhibited excellent mechanical properties, with a yield compressive strength of 1990 MPa and plastic strain of 9.12%. More over, a modified rule-of-mixture (ROM) was presented to describe the combined strengthening effect of grain refinement and TiC particles.

9.
Zhonghua Xue Ye Xue Za Zhi ; 38(11): 972-976, 2017 Nov 14.
Artículo en Chino | MEDLINE | ID: mdl-29224323

RESUMEN

Objectives: To investigate the effect of ß-catenin interacting protein 1 (ICAT) silence in Wnt signaling pathway and sterol drug NSC67657 induced cell differentiation of HL60 cell. Methods: HL-60 cells were treated with NSC67657, the cell surface antigen CD14 expression was detected by flow cytometry. Lentivirus LV-ICAT-RNAi vector was constructed and infected HL-60 cells. Then the ICAT gene and protein expression were analyzed using real-time qPCR and Western blot technique. Furthermore, Co-immunoprecipitation assay was used to confirm the interaction of ß-catenin/ICAT proteins, and Western blot was employed to compare the expressions of Wnt signaling pathway downstream targets Cyclin D1, TCF-1 and c-Jun between Lentivirus LV-ICAT-RNAi vector infected HL-60 (HL-60i) cells and un-infected HL-60 (HL-60v) cells. The cellular differentiation of HL-60i and HL-60v cells treated with NSC67657 for 24 h was evaluated by Wright's staining, transmission electron microscopy and flow cytometry analysis. Results: HL-60 cells could be induced to differentiate into monocytes by 10 µmol/L NSC67657. The CD14 positive cells could reach to (92.30±5.14) % after NSC67657 treatment for 5d. The co- immunoprecipitation assay demonstrated that ICAT protein did interact with ß-catenin protein, and the absorbance of protein electrophoresis bands increased in differentiated cells. The expressions of Wnt signaling pathway downstream target proteins in HL-60i cells were higher than that in HL-60v cells when they were treated by 10 µmol/L NSC67657, but lower than NSC67657 untreated cells. CD14 positive HL-60i cells were significantly lower than that of HL-60v cells[ (8.33±3.14) % vs (19.08±4.73) %]when treated with NSC67657, but still higher than that of uninfected and untreated HL60 cells[ (0.60±0.03) %] (F=119.24, P=0.010) . The results of cellular morphology and ultrastructure observation were also in accord with that of cell surface antigen analysis. Conclusions: ICAT does participate in HL-60 cells monocytic differentiation induced by NSC67657, and Wnt/ß-catenin signaling pathway might play a bridge role.


Asunto(s)
Vía de Señalización Wnt , Diferenciación Celular , Células HL-60 , Humanos , Mesilatos , Esteroides , beta Catenina
10.
Zhonghua Yi Xue Za Zhi ; 96(2): 113-7, 2016 Jan 12.
Artículo en Chino | MEDLINE | ID: mdl-26792693

RESUMEN

OBJECTIVE: To evaluate the interference of hemoglobin variants J-Bangkok on glycated hemoglobin (HbA(1)c) detected by five measurement systems. METHODS: Seventy cases of blood samples were collected at Zhongshan Hospital of Sun Yat-sen University from July 2012 to January 2014, the blood samples were divided into the normal control group (40 cases) and Hb J-Bangkok variant group (30 cases), and the normal control group was divided into healthy control group (20 cases) and diabetic group (20 cases). HbA(1)c measurement systems were Primus Ultra2, Variant Ⅱ, Variant Ⅱ Turbo, Modular P and Leadman. Based on the standard of the American National Glycosylated Hemoglobin Standardization Program (NGSP), Primus Ultra2 was used as comparative system, and the other 4 systems were test systems. Comparative analysis and bias evaluation were conducted on the results from five detection systems in different groups, statistical analysis were used for evaluating the differences. The estimated average glucose (eAG) was calculated by HbA(1)c values and fasting plasma glucose (FPG) of Hb J-Bangkok variant group with the different detection systems. Deming regression analysis was used to determinate whether Hb J-Bangkok produced significant clinical effect on HbA(1)c results. HbA(1)c ± 10% and relative bias at 6% and 9% HbA1c were evaluation limits. RESULTS: The differences of the 95% confidence interval (95%CI) between the test systems and the comparative system in control group were within ±0.7% HbA(1)c, bias were less than 6%, there were no statistically significant difference (P>0.05). In Hb J-Bangkok group, the eAG calculated from HbA(1)c measured by using Primus Ultra2, Modular P and Leadman were (8.14±2.99), (8.10±3.06) and (8.23±3.00)mmol/L, which had no statistically significant difference compared with FPG ((8.21±3.12)mmol/L, t=0.996, 1.091, 1.479, all P>0.05), and the differences of 95%CI between the results measured by Modular P and the comparative system were all within ±0.7% HbA(1)c, bias were -4.3%-0.4% and -5.2%-4.9%, there were no statistically significant difference (P>0.05). At 6% and 9% HbA(1)c concentrations, the mean differences of the results from the three detection systems were less than the clinically acceptable range. These results showed that the systems of Primus Ultra2, Modular P and Leadman were not affected by Hb J-Bangkok. However, the eAG values calculated from HbA(1)c of Variant Ⅱ and Variant Ⅱ Turbo were (5.58±2.12) and(5.00±2.13)mmol/L, which showed statistically significant lower results compared with FPG level (t=12.29, 13.23 , all P<0.001). Compared with Primus Ultra2, the differences of 95%CI were outside of ± 0.7% HbA1c, bias were -31.9%--12.0% and -42.0%- -17.6% , greater than 6%, showed a negative bias.At 6% and 9% HbA(1)c concentrations, the mean differences of the results were all greater than the clinical acceptable range. These results indicated that Hb J-Bangkok had significantly clinical interference on Variant Ⅱ and Variant Ⅱ Turbo systems. CONCLUSION: Hb J-Bangkok has different interference on different HbA(1)c measurement systems, when performs the HbA(1)c test, clinical laboratory should pay attention to identify Hb variants, and select the appropriate methods to measure the HbA(1)c values in order to prevent the occurrence of interference by Hb variants.


Asunto(s)
Pruebas Hematológicas , Diabetes Mellitus , Hemoglobina Glucada , Hemoglobina J , Humanos , Estándares de Referencia , Tailandia
11.
J Biol Regul Homeost Agents ; 29(3): 683-7, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26403407

RESUMEN

This study introduces the application of a new femoral distractor in the treatment of femoral fracture restoration with internal fixation of intramedullary nail. Sixty-three patients with femoral fracture from the Affiliated Hospital of Binzhou Medical University underwent femoral facture restoration with the new femoral distractor in combination with internal fixation of an intramedullary nail from June 2011 to March 2014. There were 18 cases of proximal femur fractures, 44 cases of middle femoral shaft fractures and 1 case of distal femur fracture. Follow-up was on the 4th, 6th, 8th, 12th, 16th and 24th week after operation. All 63 patients successfully underwent the surgery and the steel needles used did not cause injury to the adjacent vessels or nerves. Five cases had to have steel needles reinserted, as they had failed in the distraction reduction due to being unsteadily fixed because of an improper position. Patients were followed up for 10~24 months (mean 16 months), and the total healing rate was 100%. Operative time was 93.5 minutes averagely. Average time of patients’ exposure to X-ray was 26.8 seconds. Bleeding volume was averagely 219.1 ml. There were no complications either during the operations or after them. All cases healed within 12 weeks (average 7.6 weeks). This study proves that, the new femoral distractor can help the closed reduction of fractures in treating femoral fractures with intramedullary nails to avoid the inconvenience of applying traction tables and the occurrence of potential complications.


Asunto(s)
Clavos Ortopédicos , Fracturas del Fémur/cirugía , Curación de Fractura , Procedimientos Ortopédicos/métodos , Adolescente , Adulto , Anciano , Femenino , Fracturas del Fémur/diagnóstico por imagen , Fracturas del Fémur/fisiopatología , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Radiografía , Factores de Tiempo
12.
Mater Sci Eng C Mater Biol Appl ; 44: 76-86, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25280682

RESUMEN

Effects of thermomechanical treatment on the microstructure and superelasticity of Ti-7.5Nb-4Mo-2Sn biomedical alloy were investigated by using XRD measurement, optical microscope (OM), transmission electron microscope (TEM) and tensile tests. The titanium alloy samples were prepared by annealing at a temperature in the range of 600 to 1000°C after severe cold rolling; and the samples that were annealed at 800°C were further aged at 600 and 700°C. The volume fraction of α phases decreased while that of ω phases increase with increasing annealing temperature. The αâ†’ß transformation temperature of the alloy was determined to be between 700 and 800°C. The alloy that was annealed at 700°C exhibited a high level of superelasticity with relatively high first yield stress (σSIM) at room temperature because it contained a fine α phase. A certain amount of ω phases also resulted in an increase in σSIM, leading to an improvement in the superelasticity of the alloys that were annealed at 900 and 1000°C. Aging treatment led to the precipitations of α and ω phases in the alloy after annealing at 800°C; and the volume fraction of α phases decreased while that of ω phases increased with increasing aging temperature. Excellent superelasticity with high recovered strain (εrecoverable) and strain recovery rate (η) were obtained in the aged alloy due to the reinforcement of α and ω phases induced by aging treatment. The alloy annealed at 700°C for 0.5h exhibited the best superelasticity in all the thermomechanically treated alloys due to the strengthening from the subgrain refining and the precipitating of fine α phases.


Asunto(s)
Aleaciones/química , Calor , Titanio/química , Tecnología Biomédica , Elasticidad , Microscopía Electrónica de Transmisión , Estructura Molecular , Difracción de Rayos X
13.
J Chem Phys ; 141(5): 054307, 2014 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-25106587

RESUMEN

Previous experimental work has shown that a phase transition in C60 multifragmentation induced by nanosecond laser occurs at almost constant temperature covering a wide range of laser fluency. Here the relative yields of ionic fragments (IFs) C(n)(+) (n = 1-20) resulting from the multifragmentation are measured within the phase transition region. By excluding two small IFs and magic IFs due to their abnormal behavior, the data for residual IFs are used to estimate the size distributions of primary intermediate-mass IFs in the multifragmentation regime. The distributions are found to obey power laws n(-τ). Furthermore, the exponent τ values have sensitive dependence on lower laser fluency and converge to a constant of about 2.4 ± 0.2 for larger fluencies. These observations are in good agreement with an explanation based on the Fisher droplet model, offering the tantalizing possibility of a liquid-to-gas phase transition in C60 systems.

14.
J Mater Chem B ; 2(36): 5972-5981, 2014 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-32261849

RESUMEN

The influences of cold rolling (CR), recovery and recrystallization on the microstructure, mechanical properties and superelasticity of the suction cast Ti-7.5Nb-4Mo-2Sn alloy were investigated. It has been found that, with the increase of the CR thickness reduction rate, the volume fraction of the strain-induced martensite transiting from the ß phase increases. During annealing treatment, the precipitation of α and ω phases occurred at 700 and 800 °C, respectively, and the volume fraction of the α and ω phases increases with increasing CR thickness reduction rate. The high density of dislocations introduced by cold rolling can accelerate the course of α and ω transformation. The cold rolled alloy after annealing at 700 °C exhibits excellent superelasticity with a high first yielding stress (σSIM), a large recoverable strain (εrecoverable) and a high strain recovery rate (η) due to the retention of massive dislocations and α phase precipitates in the recovery process. The grain size shows a strong effect on the martensitic transformation, and the relationship between the critical stress for the martensite transformation and grain size follows the Hall-Petch equation with a slope of approximately 0.27 MN m-3/2.

15.
J Mech Behav Biomed Mater ; 20: 29-35, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23455161

RESUMEN

The superelasticity of a ß Ti alloy, Ti-7.5Nb-4Mo-2Sn (in atom percent) was evaluated by using loading and unloading cyclic tensile tests under different thermomechanical conditions, and the effects of the plastic deformation, temperature, strain rate and cyclic loading on the superelasticity of the alloy were studied. It is found that, with the applied strain increasing, the stress inducing the reverse martensitic transformation σα″-ß and the strain recovery rate η decreases. The increase of deformation temperature promotes σß-α″, σα″-ß and Δσ, and the temperature dependency of the stresses obeys the Clausius-Clapeyron relation. σß-α″, σα″-ß and Δσ are independent on the strain rate when it is lower than 8.35×10(-4)s(-1). However, when the strain rate is higher than 8.35×10(-4)s(-1), σß-α″ and Δσ increase, but σα″-ß decreased with increasing the strain rate. By cyclic loading and unloading to the maximum strain of 6% at 25°C under the strain rate of 1.67×10(-4)s(-1), the alloy exhibits a improved superelasticity after seventh cycles due to the training effect.


Asunto(s)
Aleaciones/química , Materiales Biocompatibles/química , Módulo de Elasticidad , Ensayo de Materiales , Estrés Mecánico , Resistencia a la Tracción
16.
J Mech Behav Biomed Mater ; 13: 156-65, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22842657

RESUMEN

Ti-7.5Nb-4Mo-xSn (x=0-4at%) alloys were developed as the biomedical materials. The effect of the Sn content on the microstructure and superelasticity of the alloys was investigated. It is found that Sn is a strong stabilizer of the ß phase, which is effective in suppressing the formation of α″ and ω phases in the alloys. Moreover, the Sn addition has a significant impact on the mechanical properties of the alloys. With the increase of Sn addition, the yield stress of the alloys increase, but their elastic modulus, the fracture strength and the ductility decrease, and the deformation mode of the alloys changes from (322) twining to α″ transformation and then to slip. The Ti-7.5Nb-4Mo-1Sn and Ti-7.5Nb-4Mo-3Sn alloys exhibit a good superelasticity with a high σ(SIM) due to the relatively high athermal ω phases containing or the solution hardening at room temperature. Under the maximum strain of 5%, Ti-7.5Nb-4Mo-3Sn (at%) alloy exhibits higher super elastic stability than that of Ti-7.5Nb-4Mo-1Sn alloy.


Asunto(s)
Aleaciones/química , Elasticidad , Microtecnología/métodos , Molibdeno/química , Niobio/química , Estaño/química , Titanio/química , Fenómenos Mecánicos
17.
Nano Lett ; 12(7): 3385-90, 2012 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-22694316

RESUMEN

Thermal management has become a critical issue for high heat flux electronics and energy systems. Integrated two-phase microchannel liquid-cooling technology has been envisioned as a promising solution, but with great challenges in flow instability. In this work, silicon nanowires were synthesized in situ in parallel silicon microchannel arrays for the first time to suppress the flow instability and to augment flow boiling heat transfer. Significant enhancement in flow boiling heat transfer performance was demonstrated for the nanowire-coated microchannel heat sink, such as an early onset of nucleate boiling, a delayed onset of flow oscillation, suppressed oscillating amplitudes of temperature and pressure drop, and an increased heat transfer coefficient.

18.
Genet Mol Res ; 10(3): 1963-74, 2011 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-21948759

RESUMEN

Galectins can recognize and specifically bind to ß-galactoside residues, playing crucial roles in innate immune responses of vertebrates and invertebrates. We cloned the cDNA of a tandem-repeat galectin from the pearl oyster Pinctada fucata (designated as PoGal2). PoGal2 cDNA is 1347 bp long and consists of a 5'-untranslated region (UTR) of 3 bp, a 3'-UTR of 297 bp with one cytokine RNA instability motif (ATTTA), and an open reading frame of 1047 bp, encoding a polypeptide of 349 amino acids, with an estimated molecular mass of 38.1 kDa and a theoretical isoelectric point of 8.5. PoGal2 contains two carbohydrate recognition domains (CRDs); both have the conserved carbohydrate-binding motifs H-NPR and WG-EE. PoGal2 shares 50.6 and 50.9% identity with those of abalone (Haliotis discus) and the Manila clam (Venerupis philippinarum), respectively. Phylogenetic analysis revealed that the tandem-repeat galectins formed two clades for the different species. Molluscan tandem-repeat galectins were clustered into a single clade, and nematode tandem-repeat galectins were clustered into another single clade. In both clades, CRD-N and CRD-C were divided into different groups. PoGal2 mRNA was constitutively expressed in all tissues analyzed, and the expression level of PoGal2 mRNA was found to be significantly up-regulated in digestive glands, gills and hemocytes after Vibrio alginolyticus stimulation/infection. Expression profile analysis showed that the expression level of PoGal2 mRNA was significantly up-regulated at 8, 12 and 24 h after V. alginolyticus infection. These results suggest that PoGal2 is a constitutive and inducible acute-phase protein involved in the innate immune response of pearl oysters.


Asunto(s)
Galectinas/genética , Pinctada/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , ADN Complementario , Etiquetas de Secuencia Expresada , Galactósidos/metabolismo , Galectinas/química , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Biblioteca de Genes , Inmunidad Innata , Datos de Secuencia Molecular , Filogenia , Pinctada/clasificación , ARN Mensajero/biosíntesis , Alineación de Secuencia , Análisis de Secuencia de ADN , Secuencias Repetidas en Tándem
19.
Phys Chem Chem Phys ; 13(8): 3328-33, 2011 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-21258682

RESUMEN

Hot C(60) molecules under nanosecond laser excitation decay by a variety of fragmentation channels. An experimental search has been made to determine the excitation temperature of fragmented C(60)via analyzing the momentum distributions of the prompt ionic fragments C(n)(+) (n ≤ 58). It was found that all the C(60) precursors appearing as these ionic fragments have almost the same temperature and the temperature shows little variation with the laser fluences in our limited range. The results provide a clear evidence that a first-order phase transition in the fragmented C(60) is occurring at this temperature. The value of phase transition temperature is found to be about 6050 ± 250 K, which is in a good agreement with the most recent estimations based on the molecular dynamics simulation. This approach offers an experimental opportunity for studying the fragmentation thermodynamics of more complex polyatomic molecules under excitation temperature determined conditions.

20.
Xenobiotica ; 39(3): 273-81, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19280526

RESUMEN

A liquid chromatography/tandem mass spectrometry method was developed and validated for the quantitative determination of yuanhuacine (YHC), a daphne diterpene ortho-ester anticancer agent, and identification of its metabolites. Pharmacokinetic behaviour, tissue distribution, and metabolism were investigated in rabbit. YHC plasma data best fitted to a two-compartment model and were characterized by an elimination half-life t(1/2)(beta) of 11.1 h following intravenous administration. Tissue distribution studies did not identify any tissues having a high affinity for YHC. The main metabolites are proposed to be M392I, M392II, and M390, resulting from the ortho-ester group and aromatic ester bond being cleaved off simultaneously during Phase I metabolism. This investigation contributes to an understanding of the metabolism of daphne diterpene ortho-esters.


Asunto(s)
Diterpenos/metabolismo , Diterpenos/farmacocinética , Modelos Biológicos , Inhibidores de Topoisomerasa I , Animales , Cromatografía Liquida/métodos , Diterpenos/sangre , Semivida , Conejos , Espectrometría de Masas en Tándem/métodos , Distribución Tisular
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