Yazar "Çelik, İ." seçeneğine göre listele
Listeleniyor 1 - 5 / 5
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Effects of Dietary Levels of Vitamin a on the Egg Yield and Immune Responses of Laying Hens(POULTRY SCIENCE ASSOC INC, 1998) Coşkun, B.; İnal, F.; Çelik, İ.; Erganiş, O.; Tiftik, A. M.; Kurtoğlu, F.; Kuyucuoğlu, Y.This research, which was designed and carried out as two consecutive experiments, investigated the effects of four different levels (0, 4,000, 12,000, and 24,000 IU/kg) of vitamin A supplementation on egg yield, plasma vitamin A levels, and immune responses of laying hens. Transmission of maternal immunity to their descendants was also studied. In the first experiment, egg yield, blood vitamin A levels, and various parameters of the immune system such as T lymphocyte levels in the peripheral blood, plasma cell counts in the spleen, and antibody titers against Newcastle Disease Virus (NDV) in the sera were investigated for a l-yr period. A total of 864 Hisex-brown laying hens were used in this experiment. The chicks were reared as commercial flocks until the 18th wk of age. No significant differences occurred among the parameters of the different diet groups. In the second experiment, maternal immunity was assessed in the chickens, supplied by hatching the eggs from hens in the first experiment. Maternal immunity was assayed by using the parameters as in Experiment 1. For this purpose, both blood and tissue samples were taken on the 2nd, 7th, and 10th d posthatch. Vitamin A supplementation had no significant effects on maternally, derived antibody titers or histologic structure of the lymphoid organs.Öğe Effects of long term oral acrylamide administration on alpha naphthyl acetate esterase and acid phosphatase activities in the peripheral blood lymphocytes of rats(TAYLOR & FRANCIS LTD, 2019) Yener, Y.; Çelik, İ.; Sur, E.; Öznurlu, Y.; Özaydin, T.Acrylamide is an important industrial chemical; it also is formed in starch-rich foodstuffs during baking, frying and roasting. Most acrylamide exposure occurs by ingestion of processed foods. We investigated possible immunotoxic effects of extended administration of low doses of acrylamide in rats. To do this, we measured alpha-naphthyl acetate esterase (ANAE) and acid phosphatase (ACP-ase) activities in peripheral blood lymphocytes. Male and female weanling Wistar rats were administered 2 or 5 mg acrylamide/kg/day in drinking water for 90days. Peripheral blood was sampled at the end of the administration period. We found ANAE staining in eosinophils and T-lymphocytes, but not in monocytes, platelets, B-lymphocytes and neutrophils. ACP-ase was found in B-lymphocytes. We found a significant reduction of the ratio of ANAE:ACP-ase in lymphocytes of the experimental animals compared to controls. We found no statistically significant differences between the doses or sexes. We found that acrylamide ingested in processed foods might affect the immune system adversely by decreasing the population of mature T- and B-lymphocytes.Öğe Efficacy of Polyvinylpolypyrrolidone in Reducing the Immunotoxicity of Aflatoxin in Growing Broilers(Carfax Publishing, 2000) Çelik, İ.; Oğuz, H.; Demet, Ö.; Dönmez, H. H.; Boydak, M.; Sur, E.1. Protective action of an enzyme-linked polyvinylpolypyrrolidone (PVPP, Mycofix(R) Plus) against the immunosuppressive effect of afatoxins (AF) was evaluated by determination of peripheral blood TP-lymphocyte proportions and splenic plasma cell counts. Histological changes in lymphoid organs were also investigated by light microscopy. One-d-old broiler chicks (Hybro) received 2.5 mg/kg diet AF (83.06% AFB(1), 12.98% AFB(2), 2.84% AFG(1), 1.12% AFG(2)) with or without PVPP (3 g/kg diet) until 21 d of age. 2. When compared with the controls, AF treatment significantly decreased peripheral T-lymphocyte counts. AF caused a slight decrease in splenic plasma cell counts. The addition of PVPP to an AF-containing diet significantly increased T-lymphocyte counts. Splenic plasma cell counts were numerically intermediate between control and AF groups. 3. The dietary addition of PVPP to AF-free diet did not significantly alter either T-lymphocyte or splenic plasma cell counts.Öğe Embryotoxicity Assay of Aflatoxin Produced by Aspergillus Parasiticus NRRL 2999(Taylor & Francis Ltd, 2000) Çelik, İ.; Oğuz, H.; Demet, O.; Boydak, M.; Dönmez, H. H.; Sur, E.; Nizamlıoğlu, F.1. The embryotoxicity of mixed aflatoxins (AF) and aflatoxin B-1 (AFB(1)) were evaluated by a modified chick embryotoxicity screening test (CHEST). Adverse effects on the early embryonic development of thymus and bursa of Fabricius were also investigated by light microscopy. AF consisted of 83.06% AFB(1), 12.98% AFB(2), 2.84% AFG(1) and 1.12% AFG(2). 2. A total of 448 fertilised laying hens' eggs were used. AF and AFB(1) were injected into the eggs at doses of 10, 100 and 1000 ng/egg. Embryonic developmental stages were evaluated according to the Hamburger-Hamilton scale (HH-scale). 3. The results showed that AFB(1) given at 10 ng/egg had a significantly (P<0.05) greater embryotoxic effect than AF given at a similar dose. The higher doses of both AF and AFB(1) caused higher embryonic mortality and also an increase in early deaths. 4. In the groups receiving 100 ng/egg AF and AFB(1) an abnormal development was seen, with a protruded central region, corresponding to the area pellucida of the blastoderm. No other developmental abnormality attributable to AF or AFB(1) was found.Öğe Represent of Mechanical Parts Using Step Standards at Computer Environment(2005) Çelik, İ.; Yaldız, S.; Ünüvar, A.Günümüzde Bilgisayarla Tümleşik İmalat Sistemlerinin geliştirilmesi hala üzerinde yoğun araştırmaların sürdürüldüğü önemli bir konudur. Araştırmalar Bilgisayar Destekli Tasarım (BDT) ile Bilgisayar Destekli Üretim (BDÜ) sistemlerinin tam olarak bütünleştirilmesinde birtakım eksikliklerin olduğunu göstermektedir. Bunlar; BDT sistemi, tam otomatik Bilgisayar Destekli İşlem Planlama (BDİP) sistemi ve BDÜ ara yüzü olarak sıralanabilir. Son yıllarda BDT sistemlerindeki özellik tabanlı tasarım yaklaşımı büyük bir gelişme göstererek BDT/BDÜ sistemlerinin bütünleşmesinde önemli bir fayda sağlamıştır. Bu çalışmada özellik tabanlı tasarım kavramıyla üzerinde delik ve kademe özellikleri bulunan mekanik bir parçanın STEP standardı kullanılarak bilgisayar ortamında temsil edilmesi ele alınmıştır.
