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1.
Molecules ; 29(18)2024 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-39339331

RESUMEN

Transition metal oxides have been widely used in microwave-absorbing materials, but how to improve impedance matching is still an urgent problem. Therefore, we introduced urea as a polymer carbon source into a three-dimensional porous structure modified by Co3O4 nanoparticles and explored the influence of different heat treatment temperatures on the wave absorption properties of the composite. The nanomaterials, when calcined at a temperature of 450 °C, exhibited excellent microwave absorption capabilities. Specifically, at an optimized thickness of 9 mm, they achieved a minimum reflection loss (RLmin) of -97.3 dB, accompanied by an effective absorption bandwidth (EAB) of 9.83 GHz that comprehensively covered both the S and Ku frequency bands. On the other hand, with a thickness of 3 mm, the RLmin was recorded as -17.9 dB, with an EAB of 5.53 GHz. This excellent performance is attributed to the multi-facial polarization and multiple reflections induced by the magnetic loss capability of Co3O4 nanoparticles, the electrical conductivity of C, and the unique three-dimensional structure of diatomite. For the future development of bio-based microwave absorption, this work provides a methodology and strategy.

2.
RSC Adv ; 11(6): 3740-3750, 2021 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-35747696

RESUMEN

Microwave irradiation is one of the most effective strategies to accelerate the curing of resin. However, the mechanism is still unclear. The debates mainly focus on how to quantitatively evaluate the 'non-thermal' effect of the microwave. In this work, the non-thermal effect on DGEBA with amine (D230) and anhydride (MHHPA) hardeners respectively was evaluated via an isothermal microwave curing reactor. The 'thermal effect' caused by the microwave was peeled off accurately. Iso-conversional kinetic analysis was performed based on the reaction extent from the real time FTIR spectrum, and the apparent activation energy (E a) was calculated for the quantitative evaluation of the microwave non-thermal effect. The influence caused by the polarized functional groups, reaction temperature and the transition state were explored, and the microwave non-thermal effect on the mechanical performance of the cured thermosets was evaluated. Results indicated that the microwave non-thermal effect was able to reduce the E a and accelerate the curing speed of epoxy resin. At the same time, the final curing extent was increased when the non-thermal effect of microwave was induced leading to enhanced mechanical and thermal performance.

3.
Artículo en Chino | WPRIM (Pacífico Occidental) | ID: wpr-735779

RESUMEN

The clinical outcomes of five groups of infertility patients receiving frozenthawed,cleavage-stage embryo transfers with exogenous hormone protocols with or without a depot gonadotropin-releasing hormone (GnRH) agonist were assessed.A retrospective cohort analysis was performed on 1003 cycles undergoing frozen-thawed,cleavage-stage embryo transfers from January 1,2012 to June 31,2015 in the Reproductive Medicine Center of Wuhan General Hospital of Guangzhou Military Region.Based on the infertility etiologies of the patients,the 1003 cycles were divided into five groups:tubal infertility,polycystic ovary syndrome (PCOS),endometriosis,male infertility,and unexplained infertility.The main outcome was the live birth rate.Two groups were set up based on the intervention:group A was given a GnRH agonist with exogenous estrogen and progesterone,and group B (control group) was given exogenous estrogen and progesterone only.The results showed that the baseline serum hormone levels and basic characteristics of the patients were not significantly different between groups A and B.The live birth rates in groups A and B were 41.67% and 29.29%,respectively (P<0.05).The live birth rates in patients with PCOS in groups A and B were 56.25% and 30.61%,respectively (P<0.05).The clinical pregnancy,implantation and on-going pregnancy rates showed the same trends as the live birth rates between groups A and B.The ectopic pregnancy rate was significantly lower in group A than in group B.We concluded that the live birth rate was higher and other clinical outcomes were more satisfactory with GnRH agonist cotreatment than without GnRH agonist co-treatment for frozen-thawed embryo transfer.The GnRH agonist combined with exogenous estrogen and progesterone worked for all types of infertility tested,especially for women with PCOS.

4.
Artículo en Chino | WPRIM (Pacífico Occidental) | ID: wpr-737247

RESUMEN

The clinical outcomes of five groups of infertility patients receiving frozenthawed,cleavage-stage embryo transfers with exogenous hormone protocols with or without a depot gonadotropin-releasing hormone (GnRH) agonist were assessed.A retrospective cohort analysis was performed on 1003 cycles undergoing frozen-thawed,cleavage-stage embryo transfers from January 1,2012 to June 31,2015 in the Reproductive Medicine Center of Wuhan General Hospital of Guangzhou Military Region.Based on the infertility etiologies of the patients,the 1003 cycles were divided into five groups:tubal infertility,polycystic ovary syndrome (PCOS),endometriosis,male infertility,and unexplained infertility.The main outcome was the live birth rate.Two groups were set up based on the intervention:group A was given a GnRH agonist with exogenous estrogen and progesterone,and group B (control group) was given exogenous estrogen and progesterone only.The results showed that the baseline serum hormone levels and basic characteristics of the patients were not significantly different between groups A and B.The live birth rates in groups A and B were 41.67% and 29.29%,respectively (P<0.05).The live birth rates in patients with PCOS in groups A and B were 56.25% and 30.61%,respectively (P<0.05).The clinical pregnancy,implantation and on-going pregnancy rates showed the same trends as the live birth rates between groups A and B.The ectopic pregnancy rate was significantly lower in group A than in group B.We concluded that the live birth rate was higher and other clinical outcomes were more satisfactory with GnRH agonist cotreatment than without GnRH agonist co-treatment for frozen-thawed embryo transfer.The GnRH agonist combined with exogenous estrogen and progesterone worked for all types of infertility tested,especially for women with PCOS.

5.
Nanotechnology ; 27(21): 215301, 2016 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-27079331

RESUMEN

A magnetically separatable catalyst Fe3O4@SiO2@PEI@Au (gold) nanoparticle was successfully constructed by a novel regional selective photoreduction method. Based on the photolysis mechanism of a type II photoinitiator, through controlling the distribution of polyethylene imine (PEI), Au nanoparticles about 10 nm, which are only on the surface of the Fe3O4@SiO2@PEI nanoparticle, could be photoreduced due to the PEI acting as a coordinating agent, capping agent, and photoreducing agent simultaneously. The small size Au nanoparticles endow the catalyst with a high catalytic performance toward the reduction of 4-nitroaniline to 4-aminophenol by NaBH4. In addition, magnetic Fe3O4@SiO2@PEI@Au nanoparticles could easily be recovered and could be reused at least six times still keeping catalytic efficiency higher than 95%, which contributes to their high stability and magnetization. Furthermore, compared to another reported approach, this method showed great regional selectivity of reducing metal nanoparticles by controlling the distribution of the PEI. Taking advantage of the regional selectivity of the photoreducing method could also be used to fabricate other metal nanoparticles as catalysts for various reactions.

6.
Artículo en Chino | WPRIM (Pacífico Occidental) | ID: wpr-263994

RESUMEN

<p><b>OBJECTIVE</b>To explore the correlation between resting heart rate (RHR) and blood glucose level in elderly patients with coronary heart disease (CHD) complicated by diabetes mellitus.</p><p><b>METHODS</b>Between April and July, 2011, a total of 1336 outpatients over 60 years of age recruited from 165 hospitals were asked to complete a questionnaire and received blood glucose and RHR examination. According to baseline RHR, the patients were divided into 3 groups with HRH <70 min-1 (group I, 372 cases), between 70 and 79 min(-1) (group II, 533 cases), and ≥80 min(-1) (group III, 431cases) for analysis of the relationships of RHR with blood glucose control rate.</p><p><b>RESULTS</b>HbA1c levels in the total, male and female patients differed significantly among the 3 groups (F=15.436, 15.436, and 24.270, respectively, P<0.05), and increased in the order from group I to group III. Blood glucose control rate in the total, male and female patients also differed significantly among the 3 groups (χ(2)=13.471, 6.752, and 6.522, respectively, P<0.05), and was significantly lower in group III than in group I (P<0.05). RHR was found to positively correlate with FPG, 2 hPG and HbA1c by Pearson correlation analysis (r=0.058, 0.085, and 0.058, respectively; P<0.05) and multiple linear regression analysis (β=0.075, 0.075, and 0.018, respectively; P<0.05). Multivariable logistic regression equation showed that compared with patients with RHR <70 min-1, the total, male and female patients with RHR ≥80 min(-1) had OR values of blood glucose control failure of 1.99 (95% CI: 1.23-2.37, P<0.05), 1.81 (95% CI: 1.17-2.77, P<0.05), and 2.18 (95% CI: 1.12-3.74, P<0.05), respectively.</p><p><b>CONCLUSION</b>RHR in elderly CHD patients with MD is positively correlated with their blood glucose level, and an increased RHR is associated with an increased risk of poor blood glucose control. Rigorous RHR control in such high-risk patients may prove beneficial for both blood glucose control and secondary prevention of CHD.</p>


Asunto(s)
Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Glucemia , Enfermedad de la Arteria Coronaria , Sangre , Diabetes Mellitus , Sangre , Frecuencia Cardíaca , Modelos Logísticos , Análisis de Regresión
7.
Chinese Journal of Epidemiology ; (12): 567-571, 2010.
Artículo en Chino | WPRIM (Pacífico Occidental) | ID: wpr-277733

RESUMEN

Objective To investigate the impacts of body mass index (BMI) and age on in vitro fertilization-embryo transfer (IVF) and intracytoplasmic sperm injection (ICSI) treatment in infertile patients without polycystic ovary syndrome (PCOS). Methods A retrospective study of 1426 patients during Jun. 2001 - Nov. 2009 was carried out. Multiple regression was used to analyze the effects of BMI (low weight: BMI<18.5 kg/m2, normal weight:BMI 18.5-23.99 kg/m2 and over weight-obesity: BMI≥24 kg/m2) and age (young: 20-34 years old, eld: 35-45 years old) on controlled ovarian stimulation (COH)[including:dose and duration of Gn, E2 level on day of human chorionic gonadotropin (HCG) administration, number of oocytes collected and full-grown follicles ],number of fertilization, cleavage, two-pronucleus, normal embryos and cryopreserved embryos and clinical pregnancy outcome. Results ( 1 ) Gn dose for the patients whose age were 35 and the above,had a positive correlation with age (P<0.001), 12.70% of the total variation of Gn dose was related to age (standardized partial regression coefficient was 0.343). (2) Estradiol level on day of HCG administration had a negative correlation with BMI in overweight-obesity patients, and so were the patients whose age were 35 and above (P value respectively lower than 0.037 and 0.018). 0.80% of the total variation of estradiol (HCG day) is related to age and overweight-obesity while age took greater proportion (standardized partial regression coefficients were 0.066 and 0.058 respectively). (3)For older patients, age appeared to have negative relationships with duration of Gn and number of oocytes collected, full-grown follicles, fertilization, cleavage, two-pronucleus, normal embryos and cryopreserved embryos (P<0.05). (4)Compared to young-normal weight patients, the odds ratio of pregnancy in eld-low weight and eld-overweight-obesity patients were 0.482 and 0.529 (P<0.05)respectively. Conclusion Age, but not the BMI, had significant effects on IVF/ICSI treatment. It seems that factors as losing weight before IVF or ICSI treatment effective in reducing the dose of Gn.

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