Bridging in uniaxial reinforced ceramic composites

Bu çalışmada, tek eksenli gerilme altında, merkezi bir çatlağı olan, çatlak eksenine dik lifler ile kuvvetlendirilmiş sonsuz kompozit levha gözönüne alınmıştır. Problemin formülasyonunda kullanmak üzere, çatlak boyunca lifteki gerilme ve çatlak açılması ilişkisini ifade eden köprülenme bağıntıları olan Hsueh (1988)’in kullandığı elastik köprülenme bağıntısı ve Marshall ve diğerleri (1985)’nin kullandığı sürtünmeli köprülenme bağıntısı seçilmiştir. Problemin formülasyonunda elde edilen tekil integral denklem, Chebyshev polinomları yardımı ile lineer olmayan bir cebirsel denklem sistemine indirgenmiştir. Gevrek lifler ile kuvvetlendirilmiş kompozitlere örnek malzeme olarak SiC/Al2O3 seçilmiş ve lif hacim oranının değişimine göre çözümler elde edilmiştir.Anahtar Kelimeler: Chebyshev polinomları, köprülenme, lifle kuvvetlendirilmiş kompozit malzeme, merkezi çatlaklı kompozit levha.In this study, a unidirectional fibre reinforced infinite composite plate under uniaxial stress which has a central through crack is considered. The bridging relations which express the relation between the stress in the fibre and the crack opening displacement along the crack axis as elastic bridging relation used by Hsueh (1988) and frictional bridging relation used by Marshall et al. (1985) which are consistent with infinite brittle fibre-reinforced composite behaviour are chosen to be utilised in the formulation of the problem. The differential equation which contains Airy stress functions of a centrally cracked orthotropic plate is solved through Fourier transform techniques and the stresses in plane are obtained in terms of the crack surface derivative. The singular integral equation system obtained for the formulation of the problem, is reduced to the solution of a non-linear system of algebraic equations by introducing Chebyshev polynomials which have closer roots near to crack tips. Stress intensity factor at crack tips, crack opening displacement and the point where the bridging type considered changes on the crack axis can be calculated. SiC/Al2O3 is chosen as an example of brittle fibre-reinforced composite material and the effect of the variations of the fibre volume ratio is presented.Keywords: Bridging, fibre-reinforced composite, centrally cracked infinite plate, Chebyshev polynomials

A preliminary study of the effect of phytoadditive carvacrol on the trace elements (Cu, Mn and Zn) content in fish tissues

Phytoadditives have gained increasing interest as feed additives for fish. The aim of the present study was to determine whether selected dietary phytoadditive can influence the bioavailability of several trace elements (Cu, Mn and Zn), which play an important role in the physiological processes. The experiments were carried out at a commercial trout farm. A total of 420 juvenile rainbow trout (mean weight ± SD = 10.79±0.57), Oncorhynchus mykiss, were randomly allocated into four different treatments with three replicates each. Fish were kept in raceways (3X0.8X0.4 m) at 10±1°C with a natural photoperiod. Proper amount of carvacrol was sprayed on 1 kg of commercial trout diet to prepare four diets with 0 (Control, C0), 1 (C1), 3 (C3) and 5 (C5) carvacrol g/kg diet. Fish were fed to apparent satiation three times per day. The feeding trial lasted four weeks. Then, in different type of fish tissues (muscle, liver and pyloric caeca) from fish fed with diets enriched in carvacrol, beneficial elements (Cu, Mn and Zn) were analysed by atomic adsorption spectrophotometer. Results showed that the levels of Cu, Zn and Mn were especially significantly increase by C1 diet in all tissues (muscle, liver and pyloric caeca) except muscle and pyloric caeca Zn. The results of this experiment indicate that the carvacrol had the ability to potentiate the trace element retention. Although bioaccumulations of Cu, Zn and Mn in the muscle, liver and pyloric caeca are well demonstrated, the exact mechanisms of phytoadditives are still only partially understood. More investigations are required to detail the mechanisms involved in phytoadditives this enhancement

Pheochromocytoma ın pregnancy: a case report

Bu yazıda ağır fetal distress saptanarak acil olarak sezaryen ile doğum yaptırılan, kronik hipertansif olarak takip edilmiş bir gebede, feokromasitoma tanısı konularak kronik hipertansif gebelerde hipertansiyon etiyolojisinin araştırılmasının önemi vurgulanmıştır. Gebelikte nadir görülen feokromasitoma nedeniyle literatür gözden geçirilmiştir.Chronic hypertension is a challenging problem in pregnancy. A pregnant woman with a long history of hypertension had undergone caesarian section because of severe fetal distress. Pheochromocytoma was diagnosed postoperatively. The importance of evaluating the etiology of chronic hypertension in pregnancy is emphasized and related literature is reviewed

Severe kyphoscoliosis ın pregnancy: a case report

Gebelikte kifoskolyoz ve beraberinde bulunan tıbbi koşullar kendine özgü takip gerektirir. Çoğunlukla sorunsuz olmakla birlikte bazı durumlarda gebeliğin sonlandırılması gerekmektedir. Ağır kifoskolyoz nedeniyle sevk edilen, primigravid age, makat prezentasyon ve oblik duruş, 32 haftalık gebeliği olan olgunun takibi ve tedavisini sunduk. Solunum zorluğu, bel ve kaburgalarda ağrı ve hareket kısıtlılığı nedeniyle doğum, preterm olarak sezaryen ile gerçekleştirildi.Pregnancy with kyphoscoliosis may need modified management because of the severity of kyphoscoliosis and her other medical conditions. Although most of the pregnancies can be completed successfully some cases are advised as medical abortion. The primigravid age patient referred to clinic suffering form pain due to severe kyphoscoliosis at her 32nd week of pregnancy with breech presentation and oblique lie. The case we reported was performed preterm birth with cesarean section because of difficulty in respiration, spinal and rib pain and restricted movements

The contraception methods preferred bywomen who demand legal abortion and their attitude about contraception methods following ınduced abortion ın Aydın.

Amaç : Aydın'da yasal tahliye amacıyla başvuran kadınların kontraseptif kullanım özelliklerini ve tahliye sonrasında kullanmayı düşündükleri kontraseptif yöntem hakkındaki fikirlerini öğrenmek için yapılan tanımlayıcı bir anket çalışması. Yöntem : Adnan Menderes Üniversitesi Tıp Fakültesi Kadın Hastalıkları ve Doğum Anabilim Dalı ve Aydın Doğum ve Çocuk Bakımevi Hastanesi Aile Planlaması Polikliniği`nde rastgele günlerde yasal gebelik tahliyesi amacıyla başvuran 107 kadın ile tahliye öncesinde yüz yüze görüşme yapıldı. Tanımlayıcı bulgular aritmetik ortalama ± standart sapma ve yüzde değerleri ile verildi. Bulgular : Çalışmaya alınan kadınların gebe kaldıklarında kullandıkları yöntemler: 21'i (%20) korunmamış, 71'i (%66) geri çekme, 11'i (%10) takvim yöntemi, 3'ü (%3) kılıf ve 1'i (%1) rahim içi araç (RıA). Bundan sonra nasıl korunmayı düşündükleri sorulduğunda, 48'i (%44) RıA, 22'si (%20) hap, 8'i (%8) tüp bağlatma, 8'i (%8) kılıf, 2'si (%2) enjeksiyon, 2'si (%2) geri çekme yöntemini tercih edeceklerini ve 17'si (%16) ise henüz bir tercihi olmadığını ifade etmiştir. Sonuç : Yasal tahliye sonrası danışmanlık çok büyük önem kazanmaktadır. Evlilik öncesinde rutine girecek bir danışmanlık hizmetine gereksinim vardır. Yasal tahliye için başvuran kadınlar yasal tahliyeyi halen bir aile planlaması yöntemi olarak görmektedir. Temel çözüm etkili alternatif yöntemler önermek ve kullandıkları yöntemlerle ilgili karşılaşılan sorunlara yönelik bilgilendirmede bulunmaktır. Aile Planlaması hizmetlerinin organizasyonunda hizmet sonrası danışmanlık gerekli ve zorunlu bir örgütlenmedir.Objective: This descriptive study was designedto determine the contraception method preferred by womenwho demand legal abortion and their attitude about contraception methods following legal abortion inAydın. Methods: Hundred and seven women admitted to Adnan Menderes University Faculty of Medicine, Department of Obstetrics and Gynecology and Aydın Maternity and Childcare Hospital for legal abortion participated in this questionnaire on random days. The questionnaire was filled out by interview. The descriptive results were analyzed and obtained in the format of average ± standard deviation and a percent ratio. Results: The methods used by women at the time they got pregnant were as follows; 21 (20%) no method, 71 (66%)coitus interruptus, 11 (10%) calendarmethod, 3 (3%)condomand 1 (1%) intrauterine device (IUD).Atthe time of procedure, the contraception methods they would prefer following induced abortion were as follows, 48 (44%) iUD, 22 (20%) oral contraceptive steroid pills, 8 (8%) surgical sterilization, 8 (8%) condom, 2 (2%) oral contraceptive steroid injections, 2 (2%) coitus interruptus and 17(16%) no decision. Conclusion: Counseling for family planning is gaining more importance following legal abortion. Routine pre-marriage counseling for family planning is necessary. Women participated in this study still think that legal abortion is a family planning method. A major solution would be advising alternative effective methods and informing women about the pitfalls of the methods they were using. Follow-up counseling for family planning services is amandatory component ofthe organization

The early effect of estrogen replacement therapy on exercise capacity in healthy postmenopausal women

Although different effects of estrogen replacement therapy (ERT) on resting hemodynamics in postmenopausal women to exercise has not been investigated.We aimed to evaluate the early effect of ERT on blood pressure, heart rate and workload in rest and during exercise. The study group consisted of 12 menopausal women (49.50 4.15 years old) Subjects received 1mg/day estrogen. No subjects had a history of cardiovascular disease or arterial hypertension, diabetes mellitus, or hyperlipidemia and none smoked. No women took ERT before the study. Exercise stress test was performed at baseline and after 6 2 days of each treatment. Bruce protokol was used for the exercise test. Blood pressure and heart rate were used to calculate the rate-pressure product at rest and during exercise. Reasons for stopping at baseline included fartique (n:10) and shortness of breath (n:2). During ERT, the reason for stopping exercise was fatique (n:12) in all patients. Blood pressure, heart rate, the rate-pressure product and exercise duration were evaluated.Wilcoxon signed-ranks test was used for statistical analysis. During rest and exercise, there was no significant difference in heart rate, systolic blood pressure, diastolic blood pressure and the rate pressure product after ERT. However exercise duration was foun to be increased significantly afterERT(440 66 secretary vs 476 59 secretary, p=0.002). In conclusion, exercise duration may be increased by ERT early in the course of therapy at first week. This effect may be due to the vascular and cardiac effects of theERT.Östrojen replasman tedavisinin(ÖRT) postmenopozal kadında istirahat hemodinamiði üzerine etkisi çeşitli çalışmalarda yayınlanmasına raðmen, egzersiz hemodinamiði üzerine etkisi araştırılmamıştır. Bu çalışmada ÖRT'nin istirahatte ve egzersizde kan basıncı, kalp hızı, ikili ürün üzerine erken dönem etkilerini araştırmayı amaçladık. Çalışmaya 12 postmenopozal kadın (Ortalama yaş 49.504.15) alındı. Olgulara 1mg/gün östrojen verildi. Kardiyovasküler hastalık veya hipertansiyon öyküsü olan, diyabet ve hiperlipidemisi olan olgular çalış maya kabul edilmedi. Hiçbir olgu sigara içmiyordu. Çalışmadan önce hiçbir olgu ÖRT almamıştı. Egzersiz testi (ET) tedaviye başlamadan önce ve başladıktan ortalama 6.082.68 gün sonra yapıldı. ET'de Bruce protokolü uygulandı. ıstirahat ve egzersiz sırasındaki kan basıncı ve kalp hızı ikili ürünün (Sistolik kan basıncı x kalp hızı) hesaplanması amacıyla kullanıldı. Tedaviye başlamadan önce yapılan semptomla sınırlı egzersiz testinde test 10 hastada yorgunluk ve 2 hastada nefes darlıðı nedeniyle sonlandırıldı.ÖRT tedavisi sırasında test bütün hastalarda yorgunluk nedeniyle sonlandırıldı. Kan basıncı, kalp hızı, ikili ürün (kalp hızı x kan basıncı) ve egzersiz süresi çalışıldı. ıstatistiksel analiz amacıylaWilcoxon işaretli sıralı testi kullanıldı. ıstirahatde ve egzersizde, ÖRT öncesinde ve sonrasında kalp hızı, kan basıncı ve ikili ürün açısından istatistiksel olarak anlamlı farklılık saptanmadı. Egzersiz süresi ÖRT sonrası belirgin derecede uzamış olarak bulundu (440 66sn vs 476 5 sn, p=0.02). ÖRT tedaviye başlandıktan sonra erken dönemde egzersiz süresinde uzama yapabilmektedir. Bu durumun hormonun vasküler veya kardiyak etkilerine baðlı olabileceði düşünülmüştür

Comparison of the effects of intranasal and transdermal estradiol plus dydrogestorone on lipids, lipoprotein(a) and apolipoproteins in postmenopausal women

Amaç: Bu araştırmanın amacı, postmenopozal kadınlarda, intranazal ve transdermal 17 östradiol ile didrogesteronun kombine kesintisiz hormon replasman tedavisinin, serumlipid, lipoprotein(a) ve apolipoprotein düzeyleri üzerindeki etkilerini karşılaştırmaktır. Gereç ve Yöntem: Bu prospektif araştırmaya yaşları 43-54 arasında değişen, sağlıklı 50 postmenopozal kadın dahil edildi. Olgular, 12 hafta süre ile 300 μg/g ün intranazal 17 β- östradiol (n=25) veya 50 μg/gün transdermal östradiol (n=25) almak üzere iki gruba randomize edildi. Bütün olgulara 10 mg/gün oral didrogesteron kesintisiz verildi. Araştırmanın başında ve sonunda, total kolesterol, trigliserid, HDL, LDL, VLDL, lipoprotein(a), Apo A-I ve Apo B düzeyleri, grup içi ve gruplar arasında farkın yüzdeleri karşılaştırıldı. İstatistiksel analiz içinMann-WhitneyUveWilcoxontesti kullanıldı. P<0,05anlamlı kabul edildi. Bulgular: Araştırmayı, intranazal grubunda 16, transdermal gurubunda 18 olmak üzere 34 olgu tamamladı. İntranazal östradiol grubunda, tedavi başlangıcına kıyasla, tedavi sonunda sadece apolipoprotein B düzeyinde anlamlı bir azalma izlenirken (2,0±0,4'den 0,9±0,1'ye, p=0,028), total kolesterol, trigliserid, HDL, LDL,VLDL, lipoprotein(a) ve Apo A-I düzeylerinde anlamlı değişiklik izlenmedi. Transdermal östradiol gurubunda hiçbir değişkende anlamlı değişiklik gözlenmedi. Her iki grup arasında, tüm değişkenler açısından anlamlı farklılık yoktu. Sonuç: İntranazal ve transdermal östradiolün, didrogesteron kombinasyonuyla yapılan kesintisiz hormon replasman tedavisinin, total kolesterol, trigliserid, HDL, LDL, VLDL, lipoprotein(a) ve Apo A-I düzeylerine etkileri benzerdir.Objective: To compare the effects of continuous hormon replacement therapy in the form of intranasal and transdermal 17β-estradiol combined with dydrogesterone on serum lipids, lipoprotein(a) and apolipoproteins among postmenopausal women. Materials and methods: In this prospective study, 50 healthy postmenopausal women aged 43-54 years were randomly assigned to receive either 300 μg/day intranasal 17β- estradiol (n=25) or 50 μg/day transdermal 17β- estradiol (n=25) for 12 weeks. All women also received 10 mg/day oral dydrogesterone continuously. At the end of the study, changes in serum total cholesterol, triglyceride, HDL, LDL, VLDL, lipoprotein(a), Apo A-I and Apo B levels within and percent changes between the groups were compared. Mann-Whitney U and Wilcoxon tests were used as indicated. P-values below 0.05 were considered significant. Results: Thirty-four women completed this study (intranasal group, n=16; transdermal group, n=18). In intranasal estradiol group, only apolipoprotein B levels were decreased significantly after 12 weeks of treatment (2.0±0.4 to 0.9±0.1, p=0.028) whereas no changes in the levels of total cholesterol, triglyceride, HDL, LDL, VLDL, lipoprotein(a) and Apo A-I were observed. Also, in transdermal estradiol group, no significant changes were seen in all variables. No significant differences with regard to variables were noted between the groups at the end of the study. Conclusions: The effects of intranasal and transdermal estradiol plus dydrogestorone asa continouos hormone replacement therapy on the serum total cholesterol, triglyceride, HDL, LDL, VLDL, lipoprotein(a) and Apo A-I levels are similar in postmenopausal women

Gall Bladder Diverticulum: A Case Report

Gallbladder pseudodiverticulum is an unusual and uncommon disease. This disorder may not be diagnosed until surgically resected. Preoperative; Ultrasonography findings of gallstones was diagnosed. The presentation may entail nonspecific complaints over a prolonged period as highlighted in a case report of a 50-year-old man with this disease. The incidence and pathophysiology of this disease process is correlated to the symptoms and signs of this patient. In this paper, we report imaging findings and the surgical results, procedure, and outcome are described

Duloxetine alleviates high light-induced anxiety-related behaviors in Wistar rats

Purpose: To investigate the effect of subchronic duloxetine treatment on high light-induced anxietyrelated behaviors in Wistar rats. Methods: Adult male Wistar rats (n = 30) were randomly assigned to three groups of rats (10 rats/group): control group, 30 mg/kg duloxetine group, and 60 mg/kg duloxetine group. Intraperitoneal injection of duloxetine was given once a day for ten days. The anxiolytic effect of duloxetine in the rats was assessed using light/dark box (LDB) anxiety test. Results: Anxiety-related behaviors were significantly reduced in duloxetine-treated rats, when compared with control group. The reductions were not dose-dependent (light zone time and latency time were significantly increased, while dark zone time decreased significantly, p &lt; 0.05). The number of rearings significantly increased in 30 mg/kg duloxetine group, relative to control and 60 mg/kg duloxetine groups (p &lt; 0.05). However, there were no significant differences in the number of light-todark entrances among the groups (p &gt; 0.05). Conclusion: These results show that subchronic treatment with duloxetine alleviates anxiety-related behaviors in Wistar rats

The contribution of vacuum-assisted modified Menghini type needle to diagnosis of US-guided fine needle aspiration biopsy of the thyroid

PURPOSEWe aimed to determine the contribution of vacuum-assisted modified Menghini type needle to diagnosis of ultrasound-guided fine needle aspiration biopsy (FNAB) of the thyroid evaluated by a pathologist at the bedside.METHODSA total of 147 thyroid nodules in 138 patients (122 women, 16 men) were included in this prospective study. Sonographic features of nodules, number of aspirations, pain and pain severity during the process, hemorrhage, and presence of sample obtained for cell block analysis were recorded and analyzed with the results of aspiration biopsy.RESULTSUsing the 21G modified Menghini type needle, a diagnosis could not be reached in 14.3% of nodules. Adequate samples for cell block analysis were obtained in 47 nodules (32%), 17 of which contributed to the diagnosis. While the difference between diagnostic cytopathology results and the contribution of the cell block were statistically significant, obtainability of cell block samples was not significantly correlated with the number of aspirations or the presence of a cystic component in the nodule.CONCLUSIONFNAB with 21G vacuum-assisted modified Menghini type needle is a safe procedure with very low complication rates. In addition to the cytologic smear samples, microtissue fragments obtained with this method help pathologists in the diagnosis of thyroid nodules