Comparison of the wear properties of modified ZA-8 alloys and conventional bearing bronze

In this study, an attempt has been made to examine the wear response of some modified Zn-Al based alloys and a conventional bearing bronze (SAE 660) at the sliding speeds of 0.5 ms(-1), I ms(-1), 1.3 ms(-1), 1.7 ms(-1) and 2 ms(-1) using applied load of 30 N and 45 N. The standard ZA-8 alloy and modified with 1% Ph, PX, Sn and 1% Cd alloys have been subjected to a pin-on-disc wear test under dry condition. A conventional bearing bronze has also been subjected to identical tests with a view to assess the working capability of the modified Zn-A1 based alloys with respect to existing ones. The results have shown that the ZA-8 alloy and modified with Ph, Sn and Cd alloys revealed higher wear resistance when compared with bearing bronze. In addition, wear resistance of ZA-8 based alloys increased with increasing sliding speed up to 1.7 ms-1 for 30 N and 1.3 ms-1 for 45 N, respectively. But it decreased with increasing sliding speed. The addition of Ph to the ZA-8 alloy increased wear resistance of the alloy for all of the sliding speeds at 30 N and 45 N, while the addition of Cd increased wear resistance of the ZA-8 at 45 N. But Sri alloying element caused worse wear resistance for ZA-8 alloy. On the other hand, the friction coefficients of ZA-8 and modified alloys are higher than that of the bearing bronze. Metallographic studies showed that the addition of Pb, Sn and Cd resulted in modifying on the microstructure of ZA-8 alloy. (C) 2006 Elsevier Ltd. All rights reserved

The effect of Ti-B and Sr on the mechanical behaviour of the zinc-aluminum-based ZA-12 alloy produced by gravity casting

In this study, the effect of Ti-B (0.05-0.7 wt.% Ti, 0.01 - 0.13 wt.% B) and Sr additions (0.05-0.7 wt.%) on the hardness, ultimate tensile strength (UTS), strain and fatigue properties of the gravity cast Zn-Al-based ZA-12 alloy was investigated. While the Ti-B additions had no significant effect on the hardness of the alloys, the Sr additions lowered the hardness by a small amount. UTS and fatigue resistance of the ZA-12 alloy increased with 0.05 wt.% Ti, but the addition of 0.05 wt.% Sr to the standard alloy did not change these properties significantly. In excess of 0.05 wt.% Ti and Sr, the UTS and fatigue resistance of the alloys decreased and reached a lower value than that of the standard alloy. The failure strain only increased for the ZA-12 alloy containing 0.05 wt.% Ti, then decreased with further increase in Ti content. The failure strain values of the alloys decreased with addition of Sr. Metallographic examination indicated that the addition of Ti-B strongly modified the microstructure of the standard ZA-12 alloy, but Sr did not. Ti and Sr have also formed complex-shaped intermetallic compounds, which were identified as Al5Ti2Zn and Zn5Al3Sr by X-ray diffraction and EDS analyses. It can be suggested that these particles cause a decrease in UTS, fatigue resistance, and strain to failure of the ZA-12 alloy

Continuous Use Of Major Antiepileptic Drugs Caused Side Effects On The Hormones; Thyroid, Testosterone, Gonadotropins And Prolactin

Bu çalışmada, en az bir yıldır major antiepileptik ilaç kullanan 42 epileptik hastada tiroid hormonları, testosteron, gonadotropin ve prolaktin değerleri ölçülerek ortaya çıkan değişiklikler araştırıldı. Sonuçta major antiepilepukleriın özellikle serbest T4 ve total testosteron değerlerinde azalma yaptığı belirlendi.In this work, 42 epileptic patients who were using major antiepileptic drugs more than a year, were chosen for the changes in their thyroid, testosterone, gonadotrophins, and prolactin hormone levels. Continuous use of antiepileptic drugs had a specific and statistically significant reduction in their free T4 and total testosteron levels

Effect of Origanum dubium, Origanum vulgare subsp. hirtum, and Lavandula angustifolia essential oils on lipid profiles and liver biomarkers in athletes

WOS:000744122600001PubMed ID34496170This study aims to determine the effects of essential oils of Origanum dubium (DUB), Origanum vulgare subsp. hirtum (HIR), and Lavandula angustifolia (LAV) on lipid profiles and liver biomarkers in athletes. Thirty-four trained athletes were randomly assigned to one of three experimental groups or the control group (CON). The concentrations of serum lipids and liver biomarkers were assessed before and after the 14-day essential oil intervention. Gas chromatography-mass spectrometry analysis showed 68.0 and 82.1% carvacrol in DUB and HIR, respectively, and 34.50% linalyl acetate and 33.68% linalool in LAV essential oils. One-way analysis of covariance (ANCOVA) indicated a significant difference (p = 0.001) among the groups for high-density lipoprotein cholesterol (HDL-C) when the associated preintervention values were used as a covariate. The related pairwise comparisons revealed that DUB (p = 0.001) and HIR (p = 0.024) had greater HDL-C values than CON. From the two-way ANOVA, an interaction between time (before vs. after) and the groups (DUB vs. HIR vs. LAV vs. CON) was found for HDL-C (p = 0.030). Findings indicated a significant increase in DUB (p = 0.0001) and HIR (p = 0.010) for HDL-C, and there was a significant decrease in DUB (p = 0.023) for low-density lipoprotein cholesterol. However, there was no difference in total cholesterol, triglycerides, and all liver biomarkers

The Relationship between Serum Carbonic Anhydrase I-II Autoantibody Levels and Diabetic Retinopathy in Type 1 Diabetes Patients

Objectives: To investigate the relationship between serum carbonic anhydrase I-II (CA-I and II) autoantibody levels and diabetic retinopathy (DRP) in cases with type 1 diabetes. Materials and Methods: A total of 37 type-1 diabetic patients, 17 with DRP (group 1) and 20 without (group 2), and 38 healthy control subjects (group 3) were included. CA-I and CA-II autoantibody levels were measured in serum samples obtained from each of the three groups and compared statistically. Additionally, the correlation between CA-I and CA-II autoantibody levels and the presence of diabetic macular edema was examined. Results: Mean measured CA-I autoantibody levels were 0.145±0.072, 0.117±0.047, and 0.138±0.061 ABSU in group 1, group 2, and group 3, respectively (p=0.327). The average CA-II autoantibody levels achieved in the same groups were 0.253±0.174, 0.155±0.137, and 0.131±0.085 ABSU, respectively (p=0.005). No significant difference was obtained between the subgroups of group 1, with macular edema (n=8) and without (n=9), in terms of both CA-I and CA-II autoantibody levels (p=0.501, p=0.178, respectively). Conclusion: A significant correlation was observed between the development of DRP and serum CA-II autoantibody levels in type-1 diabetic cases. However, there was no correlation between the autoantibody levels and the presence of diabetic macular edema in cases with DRP

ETIOLOGY AND PROGNOSIS IN 36 ACUTE RENAL FAILURE CASES RELATED TO PREGNANCY IN CENTRAL ANATOLIA

Aim: In this study, the reason of the acute renal failure (ARF) clinic features and results of it has examined as retrospectively. Methods: In this study, the etiology, clinical features and outcome of acute renal failure (ARF) evaluted retrospectively in the Anatolian region of Turkey. Above mentioned features were examined retrospectively in 36 ARF cases (mean age 31.6±6.8, range 17-46), related to pregnancy between 1997 and 2001. Results: The ARF has developed approximately on the 30th gestational week. The reasons of ARF were; HELLP Syndrome and preclampsia (44%) in 16 cases, postpartum hemorrhage in 7 cases (19%), placenta detachment in 5 cases (14%), septic or spontaneous abortion in 5 cases (14%), and eclampsia in 3 cases. The 5 cases related to the abortion were seen (14%) in the first trimester and others were developed (86%) in the third trimester or postpartum period. In 9 cases (25%) there were intrauterine dead. In 24 of the ARF cases (67%) had hypertension at the time of the diagnosis whereas six cases (17%) had hypotension related to the vaginal bleeding. All cases had oliguria and the avarage duration was 4.8±8.7 (2-27) days. The avarage of the staying period in the hospital was 11.7 ±7.6 ( 4-28 )days. Hemodialysis was applied to 17 cases (47%), and not needed for 19 cases (53%). Conclusion: ARF related to the pregnancy was seen commonly in the third or the later pregnancies and the most common reasons were HELLP Syndrome, placenta detachment, and postpartum hemorrhage and resulted in a high risk condition for fetal and maternal mortality therefore, we think that the number of the pregnancies should be limited and especially multipar pregnancies must be closely controlled for ARF

Effect of the P2Y12 antagonist ticagrelor on neointimal hyperplasia in a rabbit carotid anastomosis model

OBJECTIVES: In the present study, we aimed to deterimine the dose-related effects of ticagrelor, the first reversible inhibitor of the P2Y(12) receptor, found in smooth muscle cells as well as platelets, during neointimal hyperplasia in a rabbit carotid anastomosis model. METHODS: This study was an experimental, prospective, randomized controlled study including 20 New Zealand white female rabbits (6-months old; weighing 2300 +/- 300 g). Under general anaesthesia, the rabbits underwent transection of the right carotid artery and subsequent anastomosis of both ends. The study animals were divided into the following 4 groups: T1 (ticagrelor 5 mg/kg, orally, daily), T2 (ticagrelor 10 mg/kg, orally, daily), T3 (ticagrelor 20 mg/kg, orally, daily) and control (no ticagrelor treatment). The single oral doses were administered in phosphate-buffered saline. The control group received sterile phosphate-buffered saline (2 ml/kg/day, orally) for 3 weeks postoperatively. At the end of the study, the animals were killed, and the anastomosed segment of the right carotid artery and part of the left carotid artery were excised from each animal. Antibodies against transforming growth factor-beta were used in staining of arterial sections, which was followed by histomorphological and immunohistochemical studies. RESULTS: The median intimal thickness (2.0 +/- 0.14 m left vs 73.4 +/- 35.8 m anastomosed right arteries; P <0.05), the median medial thickness (70.8 +/- 5.6 m left vs 92.3 +/- 4.5 m anastomosed right arteries; P <0.05) and the index ratio of intimal thickness to medial thickness (0.03 +/- 0.00 left vs 0.8 +/- 0.35 anastomosed control right arteries; P <0.05) increased significantly in the anastomosed right arteries compared with the left carotid arteries in the control group. In the treatment groups, the intimal thickness (73.4 +/- 35.8 m in control group vs T1 32.7 +/- 19; 1 m, T2 1.9 +/- 0.09 m and T3 2.2 +/- 0.5 m; P = 0.047, P = 0.009 and P = 0.009, respectively), carotid artery intima/media ratio (0.8 +/- 0.35 in control group vs T1 0.4 +/- 0.2, T2 0.03 +/- 0.01 and T3 0.03 +/- 0.01 in ticagrelor groups; P = 0.028, P = 0.009 and P = 0.009, respectively) and medial thickness (92.3 +/- 4.5 m in control group vs T2 65.6 +/- 7.1 and T3 66.1 +/- 7.6 m; P = 0.009 and P = 0.009, respectively) decreased significantly in the anastomosed right arteries. CONCLUSIONS: This study indicates that effective doses (10 and 20 mg/kg, daily) of the antiplatelet agent ticagrelor in a rabbit model may be beneficial in prevention of intimal hyperplasia. Restenosis due to intimal hyperplasia has been high. Ticagrelor has also been linked to inhibition of smooth muscle cell proliferation and, hence, reduced intimal hyperplasia

Renal transplant results of the organ transplant center of meram medical school between 2003-2011

AMAÇ: Son dönem böbrek yetmezliği (SDBY) hastalarında en iyi tedavi şekli böbrek naklidir. Çalışmamızda, son 8 yılda merkezimizde kadavra ve canlıdan yapılan böbrek nakillerinin(BN) demografik verileri ile birlikte böbrek fonksiyonları ve posttransplant medikal komplikasyonları, hasta- graft sağkalımını araştırmayı hedefledik. GEREÇ ve YÖNTEMLER: Çalışmaya 40ı kadavradan, 26sı canlıdan BN yapılan 66 hasta (kadın/ erkek: 36/30) dahil edildi. Nakil sonrası nefroloji polikliniğine başvurularda yaş, cinsiyet, böbrek yetmezliği nedeni, diyaliz türü-süresi, nakil türü, aldıkları indüksiyon tedavileri, kullandığı idame immünsupresif tedaviler, akut rejeksiyon sayısı ve verilen tedaviler, nakil sonrası 1., 6., 12., 24. ve 60. aylardaki biyokimya-hemogram parametreleri ve medikal komplikasyonlar hasta dosyalarından retrospektif olarak elde edildi. BULGULAR: Alıcıların ortalama yaşı 4111,6 yıldı. Ortalama nakil sonrası süre 32,231,4 ay, kreatinin değerleri 1,40,9 mg/dl tespit edildi. En sık uygulanan immünsüpresif tedavi protokolü ko rtikosteroidtakrolimusmikofenolat mofetil/sodyumdu. Gecikmiş graft fonksiyonu, kronik allograft disfonksiyonu ve akut rejeksiyon oranları sırasıyla %27,3, %25,7 ve %13,6 idi. 1 ve 5 yıllık hasta sağkalımı canlıdan yapılan BNlerinde sırasıyla %100 ve %100, kadavradan yapılan BNlerinde ise %85 ve %85 olarak bulundu. 1 ve 5 yıllık graft sağkalımı canlıdan BN yapılanlarda sırasıyla %100 ve %100, kadavradan BN yapılanlarda ise %80 ve %80 olarak saptandı. En sık görülen medikal komplikasyonlar yeni gelişen diyabet ve dislipidemiydi. Erken ve geç dönemde en sık karşılaşılan enfeksiyon idrar yolu enfeksiyonuydu. SONUÇ: BN, hasta-graft sağkalımının yüksek olduğu bir renal replasman tedavi seçeneğidir. Bununla birlikte metabolik komplikasyonlar açısından yakın takip gereklidir.OBJECTIVE: Renal transplantation (RTx) is the best therapeutic modality for end-stage renal disease patients. We report 8 years single-centre experience on cadaveric and living donor RTx in terms of demographic features along with graft functions, posttransplant medical complications, patients-graft survivals. MATERIAL and METHODS: We enrolled 66 RTx (female/male: 36/30) patients including 40 cadaveric and 26 living donors. At admission age, gender, causes of renal failure, dialysis type- duration, type of RTx, induction and maintenance immunosuppressive modalities, rejection episodes, biochemistry-hemogram parameters at 1, 6, 12, 24 and 60 months after transplantation and medical complications were obtained from the medical records. RESULTS: Mean recipient age was 41±11.6 years. Mean transplant duration was 32.2±31.4 months, and the mean creatinine values was 1.4±0.9 mg/dl. The most commonly used immunosuppressive protocol was corticosteroidtacrolimusmycophenolate mofetil. Delayed graft function, chronic allograft nephropathy and acute rejection were observed in 27.3%, 25.7% and 13.6% of patients, respectively. 1- and 5-year patient survival rates were 100% and 100% for living donor patients and 85% and 85% for cadaveric patients, respectively. 1- and 5-year graft survival rates were 100% and 100% for living donor RTx patients, and 80% and 80% for cadaveric RTx patients, respectively. The most common medical complications were new onset diabetes mellitus and dyslipidemiaThe most common early and late infection was urinary tract infection. CONCLUSION: RTx is the best renal replacement therapy in terms of patient-graft survival. However, patients should be closely moniterized for metabolic complications