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1.
J Mech Behav Biomed Mater ; 143: 105869, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37150136

RESUMEN

Bamboo fiber-reinforced composites (BFRC) have gradually attracted the interest of researchers due to their excellent mechanical properties. However, the age factor can affect these composites' mechanical properties and weaken them. This study aims to explore the mechanical properties of BFRC subjected different aging tests. First, the BFRC is prepared from raw bamboo through a series of technological processes. Second, the BFRC sheets are processed into tensile and compressive samples with different directions. Third, the samples are treated with a cold-hot test and a UV dry-wet test, respectively. Finally, quasi-static experiments are carried out to study the mechanical properties of aged BFRC. The results reveal that the BFRC has significant anisotropy. The tensile strength of BFRC parallel with the axis of the reinforcing fiber is as high as 148.53 MPa. It is 26.47 times greater than the tensile strength of BFRC perpendicular to the axis of the reinforcing fiber. The mechanical responses and SEM images show that the UV dry-wet test significantly affects on the BFRC compared to the cold-hot test. It dramatically reduces the mechanical properties of the BFRC. The SEM images further indicate that cracks occur on the surface of BFRC samples under the UV dry-wet test. In addition, two aging tests have an interactive effect on BFRC, which can reduce the sensitivity of BFRC to a UV dry-wet environment. These results are expected to deepen the understanding of the mechanical properties of BFRC and provide guidance for its applicable conditions.


Asunto(s)
Estrés Mecánico , Ensayo de Materiales , Propiedades de Superficie , Resistencia a la Tracción
2.
JBRA Assist Reprod ; 26(4): 574-582, 2022 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-34995049

RESUMEN

OBJECTIVE: Male infertility secondary to exposure to gonadotoxic agents during reproductive age is a concerning issue. The aim of this experimental study was to determine the effect of Loboob on sperm parameters. METHODS: 55 healthy rats were selected, weighted and divided into five groups consisting of 11 rats each. The control group received no medication. Rats in Treatment Group 1 received 10mg/kg Busulfan and rats in Treatment Groups 2, 3, and 4 received 35,70 and 140 mg/kg Loboob respectively in addition to 10mg/kg Busulfan. Finally, the sperm parameters and weights of the rats were compared using the Kolmogorov-Smirnov, non-parametric Kruskal-Wallis, and Dunn-Bonferroni tests. RESULTS: All sperm parameters and weights were significantly decreased among rats receiving Busulfan. All dosages of Loboob were effective to enhance the motility of slow spermatozoa, while only in the rats given 70 and 140 mg/kg of Loboob saw improvements in progressively motile sperm percentages (0.024 and 0.01, respectively). Loboob at a dosage of 140mg/kg improved sperm viability. It did not improve normal morphology sperm or decrease immotile sperm counts. Loboob did not affect mean rat weight. CONCLUSIONS: Loboob offered a dose-dependent protective effect on several sperm parameters in rats with busulfan-induced subfertility.


Asunto(s)
Infertilidad Masculina , Motilidad Espermática , Humanos , Masculino , Ratas , Animales , Recuento de Espermatozoides , Busulfano/toxicidad , Semen , Espermatozoides , Infertilidad Masculina/inducido químicamente , Infertilidad Masculina/tratamiento farmacológico
3.
Int J Reprod Biomed ; 20(3): 177-184, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35571502

RESUMEN

Background: Ectopic pregnancy (EP) is one of the major causes of maternal mortality during the first trimester of pregnancy. Objective: Four treatment methods for EP including single-dose methotrexate (SD-MTX), double-dose methotrexate, expectant and surgical management were considered. Materials and Methods: In this cross-sectional study, the clinical characteristics of 365 women aged 15-44 yr who had been diagnosed with EP were reviewed from March 2017 to March 2019 in hospitals affiliated to Shiraz University of Medical Sciences, Shiraz, Iran. Receiver operating characteristics curves were plotted to determine the cut-off points for size of ectopic mass and beta-human chorionic gonadotropin (ß-hCG) that suitably discriminated between double-dose methotrexate and surgery management. Results: The most common site of EP was adnexa. According to the receiver operating characteristics analysis, surgery was the best plan for the women with an ectopic mass > 34.50 mm in diameter or with an initial ß-hCG level > 6419 mIU/ml. The ß-hCG levels in the women successfully treated with SD-MTX were significantly lower than in those with failed treatment (p = 0.02). The SD-MTX group had a higher success rate and significantly shorter duration of hospitalization, and so this was a more effective medical treatment in comparison with the double-dose protocol. Conclusion: Surgery is proposed as the best option for the cases with large ectopic mass or high ß-hCG level. SD-MTX had a higher success rate and shorter hospital stay than the double-dose protocol, and so was found to be an efficient and safe alternative. Further randomized clinical trials with larger sample sizes are recommended to validate the current results.

4.
Iran J Public Health ; 48(9): 1690-1696, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31700825

RESUMEN

BACKGROUND: Adherence to medical recommendations is very important to control gestational diabetes mellitus (GDM), as one of the most important disorders during pregnancy. In this study, we explored the impact of socio-economic status (SES) on the adherence of a cohort of GDM in Iran. METHODS: In this prospective study, 230 pregnant women with confirmed GDM were followed from Feb to Jun 2013 in a referral diabetic care center in Iran. The SES of subjects were quantified using a combined score generated by principal component analysis (PSA). Medical adherence score of subjects was measured in three follow up visits in a range of 0 to 10 and were linked to SES using linear regression model. RESULTS: The adherence scores women in the first, second, and third follow up visits were 5.06±2.12, 5.46±2.06, and 5.08±1, respectively. Women fourth quartile of SES (the highest level of SES) has a least compliance to medical orders in comparison to first quartile of SES (the lowest level of SES) with the OR -2.75 (95% Cl: -3.17, -2.23). CONCLUSION: The medical adherence of pregnant women with GDM is significantly poorer in high SES groups. Therefore, as an important determinant, we may target high SES pregnant women to control the adverse effects of the disorder more efficiently.

5.
Asian J Sports Med ; 4(1): 29-33, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23785573

RESUMEN

PURPOSE: Fungal infections are one of the most common skin infections. Athletes, especially in contact sports such as wrestlers are the group at risk of fungal skin infections (FSI). The aim of this study was to determine prevalence of FSI and some effective factors in wrestlers in Tehran, Iran. METHODS: This study was a cross-sectional descriptive study which was conducted in 2009 and subjects were wrestlers of wrestling clubs of Tehran, Iran. In this study the prevalence of FSI and its related factors was collected based on clinical history, physical examination and laboratory tests. We also determined the rate of dermatophytic contamination of wrestling mats. The relationship between independent variables and incidence of fungal infection analyzed by Chi square test and regression analysis. RESULTS: In this study, out of 454 wrestlers, 111 (24.5%) subjects had suspicious fungal skin lesions on physical examination. The Prevalence of FSI was 8.2% in all of the wrestlers (34.2% of the wrestlers with suspicious lesion). Malassezia furfur (50%) and trichophyton tonsurans (30%) were the most common causative agents. Epidermophyton floccosum (7.5%), Trichophyton rubrum (5%), Candida albicans (5%) and Trichophyton mentagrophytes (2.5%) were other isolated fungi. Eleven wrestling mats (44%) were contaminated with different fungal organisms. CONCLUSION: The prevalence of fungal skin infection in Iranian wrestlers is relatively high. Appropriate preventive measures need to be prepared and implemented to reduce incidence of FSI in wrestlers.

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