Stir casting process for manufacture of Al–SiC composites

Stir casting is an economical process for the fabrication of aluminum matrix composites. There are many parameters in this process, which affect the final microstructure and mechanical properties of the composites. In this study, micron-sized SiC particles were used as reinforcement to fabricate Al-3 wt% SiC composites at two casting temperatures (680 and 850 C) and stirring periods (2 and 6 min). Factors of reaction at matrix/ceramic interface, porosity, ceramic incorporation, and agglomeration of the particles were evaluated by scanning electron microscope (SEM) and high-resolution transition electron microscope (HRTEM) studies. From microstructural characterizations, it is concluded that the shorter stirring period is required for ceramic incorporation to achieve metal/ceramic bonding at the interface. The higher stirring temperature (850 C) also leads to improved ceramic incorporation. In some cases, shrinkage porosity and intensive formation of Al4C3 at the metal/ceramic interface are also observed. Finally, the mechanical properties of the composites were evaluated, and their relation with the corresponding microstructure and processing parameters of the composites was discussed

Spatial analysis and urban land use planning with emphasis on hospital site selection, case study: Isfahan city

Providing appropriate and equal health care to various classes of society is among the major issues in social welfare. Optimum spatial distribution and equitable locating of health services is important. Due to high population and density in the metropolis of Isfahan, quantitative and qualitative evaluation of hospitals of the city based on the related standards and regulations seems to be necessary. In this study, a combination of GIS and network analysis was used to evaluate the catchment areas of existing hospitals in Isfahan. The results indicated that existing hospitals covered only 23.91 percent of active urban areas at standard time. To promote fair access for citizens and improve the spatial distribution of hospitals based on the related standards and regulations, valuation of urban land for locating new hospital is necessary. Thus, with effective data collection in the form of layers of information such as transportation network, population density, land use, etc. using GIS and AHP model, the authors categorized urban land in 7 categories from poor to very good for construction of hospital

The effects of Vaccinium arctostaphylos on lipid profile in mild hyperlipidemia patients- a randomized clinical trial

زمینه و هدف: هایپر لیپیدمی یا افزایش چربی خون، به عنوان یک ریسک فاکتور مستقل و قابل اصلاح در بیماری های قلبی- عروقی (CVD) شناخته شده است. هدف از این مطالعه بررسی اثرات قره قاط (Vaccinium arctostaphylos) بر سطح لیپید پروفایل بیماران مبتلا به هایپر لیپیدمی بود. روش بررسی: در این مطالعه کارآزمایی بالینی دوسو کور، 50 بیمار هایپر لیپیدمی خفیف با محدوده سنی 76-14 سال انتخاب و به طور تصادفی ساده به دو گروه کنترل و مورد (هر گروه 25 نفر) تقسیم شدند. بیماران گروه مورد روزانه 2 عدد کپسول قره قاط (معادل با 2±45 میلی گرم آنتوسیانین) و گروه کنترل کپسول پلاسبو به مدت یک ماه مصرف کردند. میزان سرمی سطح تری گلیسرید (TG)، کلسترول تام (TC) و لیپوپروتئین با چگال کم (LDL) و کاهش سطح لیپوپروتئین با چگال بالا (HDL) قبل و بعد از مطالعه برای دو گروه بررسی و مقایسه گردید. یافته ها: میانگین سن، نمایه توده بدنی (BMI)، TG،HDL ، LDL وTC بین بیماران دو گروه در ابتدای مطالعه تفاوت معنی داری نداشت. میانگین تغییرات در گروه دریافت کننده قره قاط در مقایسه با گروه کنترل در پایان یک ماه، برای فاکتورهای TC(09/32±48/226 در مقابل 81/28±04/192)، LDL-C (76/23±80/132 در مقابل 46/27±36/121) و تری گلیسرید (99/96±20/226 در مقابل 76/46±56/156) کاهش معنی داری نشان داد. ولی برای فاکتورهای HDL-C و BMI تغییرات معنی داری نشان نداد. نتیجه گیری: در این مطالعه مصرف گیاه قره قاط به مدت یک ماه موجب کاهش لیپید پروفایل در افراد مبتلا به هایپر لیپیدمی خفیف شد؛ لذا این گیاه می تواند در پیشگیری از شیوع بیماری های قلبی- عروقی ارزشمند باشد

The effects of cranberry on glucose levels and HbA1C with type 2 diabetes patients- a randomized clinical trial

زمینه و هدف: بیماری دیابت یکی از شایع ترین اختلالات غدد درون ریز می باشد که سالانه بیش از 100 میلیون نفر را مبتلا می کند که در نتیجه نقص کامل یا نسبی و یا مقاومت به عمل انسولین ایجاد و کنترل نشدن آن موجب بروز عوارض قلبی، عروقی، کلیوی و چشمی می شود. هدف از این مطالعه بررسی اثرات زغال اخته (.Cornus mas L) بر سطح قند خون و هموگلوبین گلیکوزیله (HbA1C) در بیماران مبتلا به دیابت نوع 2 بود. روش بررسی: این مطالعه به صورت یک کارآزمایی بالینی، دو سویه کور، کنترل شده با دارونما به مدت 6 هفته انجام شد. 60 بیمار دیابت با محدوده سنی 65-41 سال در مطالعه شرکت کردند. بیماران به طور تصادفی به دو گروه 30 نفری کنترل (مصرف کننده کپسول پلاسبو یا دارونما به تعداد 2 عدد در روز) و گروه مورد (مصرف کننده کپسول زغال اخته به تعداد 2 عدد، معادل با 50 میلی گرم آنتوسیانین، در روز) تقسیم شدند. در ابتدا و پایان مطالعه میزان قند خون ناشتا (FBS) و هموگلوبین گلیکوزیله اندازه گیری و با کمک آزمون t و ANCOVA در دو گروه مقایسه گردید. یافته ها: در مورد خصوصیات افراد مورد مطالعه (سن، FBS، HbA1c) بین دو گروه در ابتدای مطالعه تفاوت معنی داری وجود نداشت. درگروه دریافت کننده زغال اخته در مقایسه با گروه کنترل در پایان 6 هفته، میزان فاکتورهای FBSو HbA1cکاهش معنی دار داشت (05/0>P). نتیجه گیری: کاهش میزان قند خون ناشتا و هموگلوبین گلیکوزیله در اثر مصرف زغال اخته، به منظور کنترل بیماری دیابت ارزشمند است. بروز این تغییرات احتمالاً ناشی از ترکیبات آنتوسیانینی موجود در زغال اخته است

Effects of radioiodine therapy on fertility indicators among men with differentiated thyroid cancer: A cohort study

Background: Following thyroidectomy, radioiodine therapy is the standard management of differentiated thyroid cancer. The effects of such treatment on testicular function remained a concern for cases and clinicians. Objective: We aimed to observe changes in fertility indicators in men treated with ablation. Materials and Methods: In this prospective cohort study, 18 men with differentiated thyroid cancer from June to December 2020 underwent thyroidectomy plus radioiodine therapy. Participants were grouped based on iodine dose (8 men with 30 mCi vs. 10 men with ≥ 150 mCi). Baseline values (VB) of the follicular stimulating hormone, luteinizing hormone, testosterone, and sperm analyses were measured 3 wk before iodine ablation and repeated 3 (V3) and 12 (V12) months later. They were analyzed once as a whole and once based on their groups via ANOVA and Friedman’s tests where appropriate. Results: The mean age of participants was 35.61 ± 9.74 yr. Follicular stimulating hormone levels showed a significant trend among all participants (VB: 12.51 ± 1.72, V3: 13.54 ± 1.41, and V12: 13.10 ± 1.67 IU/mL; p < 0.001). Luteinizing hormone showed a similar pattern (VB: 4.98 ± 1.27, V3: 5.65 ± 1.29, and V12: 5.21 ± 0.95 IU/mL; p < 0.001). Testosterone levels did not differ significantly from baseline. Sperm count decreased at the first checkpoint and returned to normal after 12 months (VB: 38.22 ± 19.40, V3: 32.05 ± 17.96, and V12: 36.66 ± 18.81 million/mL; p < 0.001). Sperm motility and morphology did not change significantly. Conclusion: Our research showed that even less than 5 GBq irradiation could induce a transient testicular dysfunction in the first 3 months of therapy, but it was mostly reversible after 12 months. Key words: Follicle-stimulating hormone, Iodine-131, Male infertility, Semen analyses

Antimicrobial Susceptibility Pattern of Staphylococcus aureus Strains Isolated from Hospitalized Patients in Tehran, Iran

Abstract Staphylococcus aureus is a major bacterial pathogen that causes different community-and hospital-acquired infections. Over time, strains of S. aureus have become resistant to different antibiotics including penicillinase-resistant penicillins. Having data on the local antimicrobial susceptibility pattern of this pathogen is necessary for selection of appropriate antibiotics for empirical treatment of infections due to it. To determine the antimicrobial susceptibility pattern of Staphylococcus aureus strains isolated from hospitalized patients in Tehran, Iran, In a prospective cross-sectional study performed at Imam Khomeini Hospital, samples were collected from hospitalized patients and were cultured. All positive cultures which yielded S. aureus underwent antimicrobial susceptibility testing using the Kirby-Bauer disk diffusion method on Mueller-Hinton agar. The results were interpreted after 24 hours of incubation at 37 °C. A total of 160 clinical isolates of S. aureus were collected. Most isolates were obtained from blood (29%). The overall susceptibility of isolated S. aureus strains to antimicrobial agents was 100% for vancomycin, 49.4% for amikacin, 43.8% for gentamicin, 36.8% for co-trimoxazole and tetracycline, 36.3% for cefazolin, 30.6% for cephalexin, 24.4% for oxacillin, 23.8% for erythromycin, and 3.1% for penicillin. Other than vancomycin, none of the tested antibiotics are appropriate for empirical treatment of serious S .aureus infections in our area

Serum Klotho Level and its Related Factors Among Male Opioids Addicts With Normal Renal Function Compared to Healthy Male Non-smokers and Smokers in Tabriz, Iran

Background: Klotho is an aging-suppressor gene that encodes a single-pass transmembrane protein and acts as a hormone. In this study, we aim to investigate the serum α-Klotho level in male opioids addicts with normal kidney function compared to healthy male non-smokers and smokers in Tabriz, Iran. Methods: Participnts were 87 men with normal kidney function referred to Sina Educational Research and Treatment Center in Tabriz, Iran (29 opioids addicts, 29 healthy non-smokers, and 29 healthy smokers). Blood samples were collected to measure the soluble a-Klotho level using an ELISA kit. Furthermore, blood creatinine (Cr) and hemoglobin (Hb) levels was measured. Body mass index (BMI) was also calculated for all participants.Results: In addicts, BMI, Hb, and Cr levels were significantly lower than in healthy non-smokers and smokers, but their Klotho level was higher (P>0.05). The Klotho level in healthy smokers was significantly lower than in healthy non-smokers and addicts. The Klotho level of healthy smokers decreased as the pack year increased, but the duration of opioid addiction had no significant association with the Klotho level. There was no significant difference in the Klotho level between control groups (non-smokers and smokers) and men with addiction to different types of opioids. Conclusion: The Klotho level in male opioid addicts is significantly higher than in smokers. There is a significant negative correlation between BMI and Klotho levels among men with normal BMI and overweight. Further studies are recommended in these fields

Association of Interleukin 10 And Transforming Growth Factor β Gene Polymorphisms with Chronic Idiopathic Urticaria

Transforming growth factor β (TGF-β) and interleukin 10 (IL-10) are two anti-inflammatory cytokines that are implicated in the pathogenesis of urticaria. The goal of this study was to examine the possible association of polymorphisms of TGF-β and IL-10 genes with susceptibility to chronic idiopathic urticaria (CIU). This study was conducted on 90 patients with CIU. Polymerase chain reaction (PCR) was done to determine the genotype at 5 polymorphic sites; TGF-β (codon10C/T and codon25G/C) and IL-10 (-1082G/A, -819C/T, and -592C/A). The C allele at codon 25 of TGF-β was more prevalent in CIU patients compared to controls (OR = 9.5, 95% CI = 5.4-16.8, P<0.001). Genotypes of CT and CG at 10 and 25 codons of TGF-β gene, respectively, and AG, CT, and CA for loci of -1082, -819, and -592 of IL-10 gene were significantly higher in CIU patients (P<0.001). In haplotype analysis, frequency of TGF-β haplotypes differed between patients with CIU and controls; CC haplotype was overrepresented, while CG and TG haplotypes were underrepresented (P<0.001). These results suggest that TGF-β and IL-10 genetic variability could contribute to susceptibility to CIU. Additionally, patients with CIU seem to have genotypes leading to high production of TGF-β and IL-10.</p

The Antifungal Effect of Silver, Copper Nanoparticles, and Their Combination and in combination with Amphotericin B against Candida albicans In Vitro and in Animal Model

Background and Objectives: Candida is a genus of yeasts and is considered as the most common cause of fungal infections in the medical world. In this research, the antifungal activity of silver nanoparticles, copper nanoparticles, and their combination and with amphotericin B, was investigated in order to produce an effective antimicrobial drug against against infections caused by Candida albicans. &nbsp; Methods: In this experimental study, the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) for silver nanoparticles, copper nanoparticles, and their combination form and in combination with amphotericin B, was performed based on microdilution method. Then, their antifungal effect was investigated in infected mouse model. &nbsp; Results: MIC and MFC of silver nanoparticles for Candida albicans were, respectively, 8 ppm and 15.50 ppm, of copper nanoparticles were 62.50ppm and 125 ppm, and of their combination form were 31 ppm and 62.50 ppm. MIC and MFC of silver nanoparticles in combination with amphotericin B for Candida albicans were, respectively, 15.50ppm and 31ppm, and for the combination of copper nanoparticles and amphotericin B against Candida albicans was obtained 8ppm and 15.50ppm. The mouse model study confirmed the antifungal effect of the nanoparticles against Candida albicans; so that silver nanoparticles, copper nanoparticles, and their combination showed the highest antifungal effect, and combination of silver or copper nanoparticles with amphotericin B had the lowest antifungal effect in the animal model. &nbsp; Conclusion: The results showed that silver, copper nanoparticles, and their combination form have higher antimicrobial effect compared to antifungal amphotericin B. &nbsp; &nbsp

Effect of an end plate on surface pressure distributions of two swept wings

A series of wind tunnel tests was conducted to examine how an end plate affects the pressure distributions of two wings with leading edge (LE) sweep angles of 23° and 40°. All the experiments were carried out at a midchord Reynolds number of 8×105, covering an angle of attack (AOA) range from −2° to 14°. Static pressure distribution measurements were acquired over the upper surfaces of the wings along three chordwise rows and one spanwise direction at the wing quarter-chord line. The results of the tests confirm that at a particular AOA, increasing the sweep angle causes a noticeable decrease in the upper-surface suction pressure. Furthermore, as the sweep angle increases, the development of a laminar separation bubble near the LEs of the wings takes place at higher AOAs. On the other hand, spanwise pressure measurements show that increasing the wing sweep angle results in forming a stronger vortex on the quarter-chord line which has lower sensitivity to AOA variation and remains substantially attached to the wing surface for higher AOAs than that can be achieved in the case of a lower sweep angle. In addition, data obtained indicate that installing an end plate further reinforces the spanwise flow over the wing surface, thus affecting the pressure distribution