Büyükgüzel, Kemal | Tunaz, Hasan | Putnam, Sean M. | Stanley, David

Article | 2002 | Insect Biochemistry and Molecular Biology32 ( 4 ) , pp.435 - 443

We describe prostaglandin (PG) biosynthesis by isolated midgut preparations from tobacco hornworms, Manduca sexta. Microsomal-enriched midgut preparations yielded four PGs, PGA/B2, PGD2, PGE2 and PGF22? all of which were confirmed by analysis on gas chromatography-mass spectrometry (GC-MS). PGA and PGB are double bond isomers which do not resolve on TLC but do resolve by GC; for convenience, we use the single term PGA2 for this product. PGA2 was the major product under most conditions. The midgut preparations were sensitive to reaction conditions, including radioactive substrate, protein concentration (optimal at 1 mg/reaction), rea . . .ction time (optimal at 0.5 min), temperature (optimal at 22°C), buffer pH (highest at pH 6), and the presence of a co-factor cocktail composed of reduced glutathione, hydroquinine and hemoglobin. In vitro PG biosynthesis was inhibited by two cyclooxygenase inhibitors, indomethacin and naproxen. Subcellular localization of PG biosynthetic activity in midgut preparations, determined by ultracentrifugation, revealed the presence of PG biosynthetic activity in the cytosolic and microsomal fractions, although most activity was found in the cytosolic fractions. This is similar to other invertebrates, and different from mammalian preparations, in which the activity is exclusively associated with the microsomal fractions. Midgut preparations from M. sexta pupae, adult cockroach, Periplaneta americana, and corn ear worms, Helicoverpa zea, also produced the same four major PG products. We infer that insect midguts are competent to biosynthesize PGs, and speculate they exert important, albeit unrevealed, actions in midgut physiology. © 2002 Elsevier Science Ltd. All rights reserved Daha fazlası Daha az

Büyükgüzel, Kemal

Article | 2002 | Turkish Journal of Zoology26 ( 1 ) , pp.101 - 109

Endoparazitoid zarkanatlı türü, Pimpla turionellae L., kimyasal yapısı bilinen sentetik besin ortamlarında aseptik şartlarda beslenerek farklı yapı ve etkiye sahip olan onüç antimikrobiyal ajanın böceğin pup evresindeki total protein miktarına etkileri incelendi. Bu etkiler antimikrobiyal ajanın üeşidine ve besindeki miktarına göre değişmektedir. Pupların total protein miktarı penisillin, streptomisin, rifampisin, tetrasiklin hidroklorür, linkomisin hidroklorür, metil p-hidroksibenzoat, sikloheksimid, ve sodyum benzoat tarafından önemli derecede artırılırken nistatin ise bu miktarı azaltmıştır.Diğer denenen ajanlar ise böceğin prote . . .in miktarına önemli bir etki yapmamıştır.Antimikrobiyal ajanlar aynı zamanda besinsel miktarlarına baÛlı olarak böceğin yaş vucut ağırlığı üzerinde etkili olmußtur. Bu ajanların bazı miktarlarını içeren besinler ile beslenen larvaların oluşturduğu pupların kontrol besinindekilere göre daha düşük vucut ağırlığına sahip oldukları ancak bunların daha fazla protein içerdikleri tespit edilmiştir. Nistatinin 45 mg'ının ilave edildiği besin ise pupların yaş ağırlığında ve bunların protein miktarında önemli bir azalmaya neden olmuştur. The effects of thirteen antimicrobial agents that have different structures and modes of action on the total protein content of pupae of the hymenopterous endoparasitoid, Pimpla turionellae L., were investigated by rearing the larvae aseptically on chemically defined synthetic diets. These effects varied according to the their kind and dietary levels. The protein content of the pupae was significantly increased by penicillin, streptomycin, rifampicin, tetracycline hydrochloride, lincomycin hydrochloride, methyl p-hydroxybenzoate, cycloheximide and sodium benzoate, while it was decreased by nystatin. The other tested antimicrobial agents had no significant effects on the total protein content of the insect. Depending on dietary levels, most of the tested agents also had an effect on the body wet weight of the insect. It was demonstrated that pupae from larvae fed on diets with some levels of tested antimicrobial agents had a lower body wet weight but contained more protein content than those of the control diet. The diet with 45 mg of nystatin caused a significant decrease in the wet weight of the pupae and their protein content Daha fazlası Daha az

Karataş, Ahmet | Sözen, Mustafa

Article | 2002 | Israel Journal of Zoology48 ( 4 ) , pp.359 - 360

[No abstract available]

Arslan, Hülya | Hazer, Baki | Kowalczuk, Marek

Article | 2002 | JOURNAL OF APPLIED POLYMER SCIENCE85 ( 5 ) , pp.965 - 973

Poly [(R, S)-3-hydroxybutyratel oligomers containing dihyroxyl (PHB-diol), dicarboxylic acid (PHB-diacid) and hydroxyl-carboxylic acid (a-PHB) end functionalities were obtained by the anionic polymerization of beta-butyrolacton (beta-BL). Ring opening anionic polymerization of beta-BL was initiated by a complex of 18-Crown-6 with gamma-bydroxybutyric acid sodium salts (for PHB-diol and a-PHB) or succinic acid disodium salt (for PHB-diacid). Dihydroxyl functionalization was formed by the termination of polymerization with bromo-ethanol or bromo-decanol while the others were done by protonation. Hydroxyl and/or carboxylic acid functio . . .nalized PHB oligomers with eerie salts were used to initiate the polymerization of methylmethacrylate (MXIA). PHB-b-PMMA block copolymers obtained by this way were purified by fractional precipitation and characterized using H-1-NMR and C-13-NMR, gel permeation chromatography (GPC), and thermal analysis (DSC and TGA) techniques. (C) 2002 Wiley Periodicals, Inc. J Appl Polyra Sci 85: 965-973, 2002 Daha fazlası Daha az

Kul, Dilek | Volga, Cüneyt | Yılmaz-Savaşkan, Sevil | Hazer, Baki

Article | 2002 | POLYMER BULLETIN49 ( 1 ) , pp.25 - 32

WOS: 000178013300004

Kopaç, Türkan | Kocabaş, Sefa

Article | 2002 | Chemical Engineering and Processing41 ( 3 ) , pp.223 - 230

In this work, the adsorption equilibrium and adsorption rate of sulfur dioxide were investigated on silica gel. A packed bed adsorber 0.1 m in length and 0.0095 m in diameter was used for the adsorption experiments. The adsorption equilibrium experiments were carried out at 473 K constant temperature with an initial sulfur dioxide concentration in the range 430-3400 p.p.m. in nitrogen carrier gas. The experimental adsorption isotherms were compared with the Freundlich, Langmuir, and the linearized form of the Brunauer-Emmett-Teller and the Dubinin-Radushkevitch-Kaganer models by the nonlinear least-squares estimate method. The Freun . . .dlich model gave the best fit with a correlation coefficient greater than 0.98, suggesting a surface adsorption mechanism for sulfur dioxide adsorption on silica gel. The deactivation model was applied to the adsorption rate data. It was found that the adsorption rate data fitted well with the deactivation model. Observed adsorption rate constants and the first-order deactivation rate constants were obtained from the model. The nonlinear least-squares analysis technique was used to estimate the parameters appearing in the deactivation model. The breakthrough experiments were repeated at 1610 p.p.m. constant initial sulfur dioxide concentration in a temperature range of 323-473 K, and the effect of initial sulfur dioxide concentration and the effect of temperature were investigated on the model results. © 2002 Elsevier Science B.V. All rights reserved Daha fazlası Daha az

Arkın, Ali Hakan | Hazer, Baki

Article | 2002 | Biomacromolecules3 ( 6 ) , pp.1327 - 1335

Chlorination of microbial polyesters poly(3-hydroxybutyrate) (PHB) and poly(3-hydroxyoctanoate) (PHO) was carried out by passing chlorine gas through their solutions. The chlorine contents in chlorinated PHB (PHB-Cl) and chlorinated PHO (PHO-Cl) were between 5.45 and 23.81 wt % and 28.09 and 39.09 wt %, respectively. Molecular weights of the chlorinated samples were in the range of between one-half to one-fourth of the original values because of hydrolysis during the chlorination process. Thermal properties of the PHO-Cl were dramatically changed with an increase in its glass transition (Tg = 2 °C) and the melting transition (Tm). T . . .he Tg of PHB-Cl varied from -20 to 10 °C, and its Tm decreased to 148 °C. The chlorinated poly(3-hydroxyalkanoate)s (PHA-Cl) were converted to their corresponding quaternary ammonium salts (PHA-N+R3), sodium sulfate salts (PHA-S), and phenyl derivatives (PHA-Ph). Cross-linked polymers were also formed by a Friedel-Crafts reaction between benzene and PHA-Cl. The modified PHO derivatives were characterized by 1H NMR and 13C NMR spectrometry, Fourier transform infrared spectroscopy, gel permeation chromatography, and differential scanning calorimetry techniques Daha fazlası Daha az

Büyükgüzel, Kemal | Yazgan, Şevki

Other | 2002 | Turkish Journal of Zoology26 ( 1 ) , pp.111 - 119

Endoparazitoid zarkanatlı türü, Pimpla turionellae L., kimyasal yapısı bilinen sentetik besin ortamlarında aseptik şartlarda beslenerek, farklı yapı ve etkiye sahip onüç antimikrobiyal ajanın böceğin yaşama ve gelişmesine etkileri incelendi. Bu etkiler denenen antimikrobiyal ajanın çeşidine ve miktarına göre değişmektedir. Denenen ajanların etkileri çoğunlukla larva sonrası evrelerde ortaya çıkmış olup bu evrelerdeki yaşama ve gelişme olumsuz yönde etkilenmiştir. Antimikrobiyal ajanlar aynı zamanda larval evredeki gelişmeyi de etkilemiş ancak bu evredeki yaıama üzerinde önemli bir etki yapmamıştır. Larvalar antimikrobiyal ajanların . . .hem çeşidine hem de besinsel miktarına karşı geniş bir tolerans göstermiştir. Denenen ajanların hiçbiri larvalar üzerinde toksik etki yapmam ıştır. Sodyum benzoat ve nistatinin düüşk miktarları larvaların besin tüketimine olumlu etkide bulunmuştur. The effects of 13 antimicrobial agents that have different structures and modes of action, on the survival and development of the hymenopterous endoparasitoid, Pimpla turionellae L., were investigated by rearing the larvae aseptically on chemically defined synthetic diets. These effects varied according to their kind and dietary levels. The agents tested exerted their effects generally during the post-larval development of the insect. The post-larval survival and development were negatively affected by most of the agents tested at certain levels. The antimicrobial agents tested also affected the larval development but had no significant effects on the larval survival of the insect. The larvae showed a wide tolerance against both the kind and dietary levels of the agents. None of the agents tested were toxic to the larvae. Sodium benzoate and nystatin at low levels had positive effects on the food consumption of the larv Daha fazlası Daha az

Büyükgüzel, Kemal

Other | 2002 | Turkish Journal of Zoology26 ( 2 ) , pp.229 - 237

Endoparazitoid hymenopter türü, Pimpla turionellae L., kimyasal yapısı bilinen sentetik besin ortamlarında aseptik şartlarda beslenerek bazı antibiyotik ve antifungal ajanların kombinasyonlarının böceğin genç puplarının toplam protein miktarına etkileri incelendi. Bu etkiler besindeki antimikrobiyal ajanların kombinasyonlarının çeşidine ve miktarına göre değişmektedir. Antibiyotik kombinasyonlar ının çoğu besinde tek başına bulunan miktarlarına göre toplam protein miktarını artırmıştır. Antifungal ajan kombinasyonlar ı ise antibiyotiklere göre fazla olmayan ancak istatistiksel olarak önemli bir artışa sebep olmuştur.Nistatinin metil . . . p-hidroksibenzoat veya sikloheksimid ile kombinasyonu toplam protein miktarını önemli derecede düşürmüştür. Nistatin ve metil p-hidroksibenzoat kombinasyonunu içeren besine bir antibiyotik ilave edilmesi toplam protein miktarını artırmıştır. Penisillin ve streptomisin kombinasyonunu içeren besine bir antifungal ajan ilave edilmesi bu miktarda azalmaya sebep olmuştur. Antimikrobiyal ajanların kombinasyonlar ı aynı zamanda pupların yaş ağırlığı üzerinde etkili olmußtur. Bu pupların toplam protein miktarının yaş ağırlıkları ile ters orantılı olarak değiştiği tespit edilmiştir. Protein miktarındaki artışın bu parazitoid böceğin yaşama ve gelişmesi üzerine olumlu bir etkide bulunmadığı görülmüştür. The effects of some antibiotics and antifungal agents in combination on the total protein content of young pupae of the hymenopterous endoparasitoid, Pimpla turionellae L., were investigated by rearing the larvae aseptically on chemically defined synthetic diets. These effects varied with the kinds and levels of the combination of antimicrobial agents in the diets. The combinations of antibiotics generally increased the total protein content according to their individual levels in the diets. Antifungal agent combinations caused a slight but significant increase in the total protein content. However, some tested combinations of nystatin with methyl p-hydroxybenzoate or cycloheximide significantly decreased the total protein content of the insect. The addition of an antibiotic to the diet in combination with nystatin and methyl p-hydroxybenzoate increased the total protein content. When an antifungal agent was added to the combination of penicillin and streptomycin the protein content decreased. The combinations of antimicrobial agents had an effect on the wet weight of the pupae. It was demonstrated that the total protein content of these pupae varied inversely with changes in their wet weight. It also seems as if increased protein content does not correlate with higher survivorship and life expectancy of this parasitoid Daha fazlası Daha az

Büyükgüzel, Kemal

Article | 2002 | Turkish Journal of Zoology26 ( 1 ) , pp.121 - 126

Endoparazitoid bir zarkanatlı türü, Pimpla turionellae L., kimyasal yapısı bilinen sentetik besin ortamlarında aseptik şartlarda beslenerek, güçlü antibakteriyel ajanlar olan novobiyosin, nalidiksik ve oksolinik asitin böceğin yaşama ve gelişmesine ayrı ayrı etkileri inclendi. Beşinci evredeki larvaların yaşama yüzdesi antibiyotiklerin farklı miktalarını içeren besinler tarafından önemli derecede etkilenmemiştir. Novobiyosinin en düşük miktarını içeren besin pup ve ergin yüzdesini önemli derecede artırmıştır. Bu miktar aynı zamanda beşinci evreye ulaşmak için gereken süreyi kısaltmış, ancak larvaların ergin evreye kadar gelişmesi üz . . .erinde önemli bir etki yapmamıştır. Oksolinik asitin en düşük miktarı yaşama üzerinde etkili olmazken böceğin gelişmesini geçiktirmiştir. Antibiyotiklerin yüksek miktarları genellikle gelişme oranını artırmış, yaşamayı düşürmüştür. Nalidiksik asitin denenen bütün miktarları ise yaşamayı dikkate değer bir şekilde düşürmüştür. Bu sonuçlar novobiyosinin ve bir dereceye kadar oksolinik asitin denenen en düşük miktarının böceğin biyolojik kontrol amacıyla yapay ortamlarda yetiştirilmesinde kullanılan sentetik besinlere ilave edilebileceğini göstermektedir. The effects of 13 antimicrobial agents that have different structures and modes of action, on the survival and development of the hymenopterous endoparasitoid, Pimpla turionellae L., were investigated by rearing the larvae aseptically on chemically defined synthetic diets. These effects varied according to their kind and dietary levels. The agents tested exerted their effects generally during the post-larval development of the insect. The post-larval survival and development were negatively affected by most of the agents tested at certain levels. The antimicrobial agents tested also affected the larval development but had no significant effects on the larval survival of the insect. The larvae showed a wide tolerance against both the kind and dietary levels of the agents. None of the agents tested were toxic to the larvae. Sodium benzoate and nystatin at low levels had positive effects on the food consumption of the larvae Daha fazlası Daha az