Clinical Use of Progesterone and Its Relation to Oxidative Stress in Ruminants

Studies to determine the physiological effects and functions of progesterone started in the twentieth century. Progesterone is a steroid-structured hormone with 21 carbon atoms originating from cholesterol. The corpus luteum, formed after ovulation in ruminants, secretes progesterone, which plays a role in the continuity of the pregnancy. Progestagens can be used for estrus synchronization in cows and heifers. Similarly, they are used for estrus synchronization during the breeding season or outside the breeding season by taking advantage of the negative feedback effect of progesterone in small ruminants. It is applied for the treatment of embryonic deaths due to luteal insufficiency in cows with high milk yield. In anovulatory anestrus, exogenous progesterone applications can be very useful. Progesterone treatment contributes to the resolution of the anestrus by rearranging hypothalamic functions in cattle with follicular cysts. The oxidative stress index in the luteal phase, when progesterone is high in ruminants, is higher than in the follicular phase. In the critical period of pregnancy, a high index of oxidative stress-induced progesterone causes embryonic death. Factors that cause stress in high milk-yielding cows can affect the amount of progesterone synthesis by inhibiting luteal cell function due to excessive free radical production

S-SBR (Solution Stiren Bütadien Kauçuk) Bazlı Kauçuk Karışımlarına Farklı Karbon Siyahlarının Etkisi

Lastik endüstrisinde ya da diğer kauçuk sektörlerinde kullanımı yüksek elastomer malzemeler stiren bütadien kauçuk (SBR) ve doğal kauçuklardır (NR). Bu çalışmada, S-SBR (solution-stiren bütadien kauçuk) ve ASTM standardına göre adlandırılan farklı gradelerdeki karbon siyahları ile reçeteler hazırlandı ve hazırlanan reçetelerin reolojik ve fizikomekaniksel davranışları araştırıldı. S-SBR miktarı sabit tutularak (137,5phr) karbon siyahlarından N220, N234, N326, N330, N375, N550, N660, N772 gradeleri 80phr olarak kullanılmış 8 reçete hazırlanmıştır. Yapılan testlerin sonucunda; karbon siyahlarının tanecik yapılarının farklı olması ile karışımların reolojik ve mekaniksel değerleri incelenmiş, tanecik boyutunun ve kümeleme(aggregrate) yapısına sahip olmasının belirgin şekilde değerleri etkilediği değerlendirilmiştir. Farklı yapılardaki karbon siyahlarının S-SBR bazlı reçetelerde etkilerinin karbon yapısı, yüzey alanı, kümeleme yapılarının yoğunluğuna göre değiştiği anlaşılmıştır

Lastik Karışımlarında Klasik ZnO Yerine Aktif ZnO Kullanımının Bazı Fizikomekanik Özelliklere Etkilerinin Araştırılması

Kauçuk esaslı ürünlerin imalatında kullanılan katkı malzemeleri; zamana, maruz kaldığı fiziksel ve kimyasal etkilere bağlı olarak üründen kısmen ayrılmaktadırlar. Ortamdan ayrılan bu katkı malzemeleri imal edilen mamulün performansını ve uzun sürede kullanım ömrünü azaltmaktadır. Bu çalışmada aktif ZnO ile normal ZnO kullanılarak üretilen kauçuk malzemelerin maliyet –performans özellikleri incelenmiştir. Bulgular daha yüksek yüzey alanına sahip aktif ZnO tercihiyle, mekanik testlerde %20, toplam mamul ağırlığında %5 ve maliyette %2’e varan bir farklılık hesaplanmıştır

BİYOKİMYA LABORATUVAR DERS NOTLARI

tıp, fen edebiyat kimya ve biyokimya öğrencilerinin yararlanabileceği laboratuvar dersi pratik ve teorik bilgileri.&nbsp;</p

Dermatoglypic findings in periodontal disease

The finger-tip palm and sole prints of 13 male and 23 female, a total of 36 patients with juvenile periodontitis (JP) 24 male and 21 female, a total of 45 patients with rapidly progressive periodontitis (RPP) and 19 male and 19 female, a total of 38 patients with adult periodontitis (AP) were compared with those of 17 male and 22 female, a total of 39 periodontally healthy (PH) individuals for the aim of finding a pattern type that would identify those patients. Besides, the finger-tip and palmar patterns of the patients were compared with those of 446 male and 447 female, a total of 833 school children (SC), and the sole patterns of the patients were compared with those of 250 male and 250 female, a total of 500 SC. When, the finger-tip patterns of the patients were compared with those of PH individuals, the decreased frequencies of twinned and transversal ulnar loops on all fingers of the patients with JP, a decreased frequency of double loops on all fingers and an increased frequency of radial loops on the right second digits of the patients with RPP, and the increased frequencies of concentric whorls and transversal ulnar loops on all fingers of the patients with AP, an increased frequency of t″ triradii on the palms of the patients with JP, the increased frequencies of IV and H loops and tb triradii on the palms of the patients with RPP and an increased frequency of e triradii on the soles of the patients with JP were found. In summary, in the light of these findings dermatoglyphics could be used together with the other diagnostic methods such as clinical and radiologic investigations and in the identifying of the patients from distinct groups of PD’s

Thermal decomposition kinetics of polypyrrole and its star shaped copolymer

Thermal behavior of 2,4,6-tris(4-(1H-pyrrol-1-yl)phenoxy)-1,3,5-triazine monomer, polypyrrole, and their star shaped copolymer, were investigated using TG and DTA methods. It was found that Tria melts at 517 K and after than it starts to decompose. Decomposition proceeded in two stages which were corresponding to removal of branched groups and remaining core structure degradation, respectively. Polypyrrole and copolymer showed similar thermal behaviors. These compounds decomposed in three stages which are removal of solvent, removal of dopant anion and rest of structure decomposition. The calculation of activation energies of all reactions were realized using model-free (KAS and FWO) methods. The graphs were prepared which show the alteration of activation energy with decomposition ratio. Thermal analysis results showed that dopant anion and solvent removal activation energy values for copolymer are lower than polypyrrole. Star shaped loose-packed novel structure greatly facilitates solvent and dopant anion removal from copolymer. It can be concluded also that thermal analysis can be used as predict package structure of conducting polymers

Passive immunity in lambs: Colostral and serum gamma-glutamyltransferase as a predictor of IgG concentration and related to the diseases from birth to 12 weeks of life

Erdoğan, Hidayet Metin ( Aksaray, Yazar )The main goal of this study was to find a link between colostrum and the 1-day-old lamb serum gamma-glutamyltransferase (GGT) activity and immunoglobulin G (IgG) concentration and their relation with neonatal diseases and beyond. Further, to set a linear relationship between the serum GGT activity (SGGTA) and the IgG concentration (SIgGC) in different days of the neonatal period, thereby determining the feasibility of the GGT activity in the prediction of the colostrum quality and passive immunity and to define a cut-off point for the SGGTA associated with an increased risk of illness or death in lambs. For this purpose, blood samples were obtained from the lambs before the colostrum intake (day 0) and on different days (1, 2, 4, 7, 14 and 28) in the neonatal period. The colostrum was collected from the respective ewes (n = 254) related to the lambs. The most accurate (R-2 = 0.652) model for predicting the SIgGC or passive immune status was the multiple regression model developed to calculate In[IgG] from In [GGT] in healthy neonatal lambs using the serum GGT and IgG values of day 0, 1, 2, 4, 7, 14 and 28. The In [GGT] activity at 24 h after birth in lambs that died or became ill during the neonatal period accounted for approximately 77% and 88% of the variation in the In[IgG] concentration at 24 h after birth, respectively. The study revealed that SGGTA-24 > 500 IU may be considered as a critical cut-off point for the adequate colostral passive transfer. This study also disclosed that the colostral GGT activity might be used as an indicator to determine the colostrum quality