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1.
Nagihan Saglam Ahmet Colak Kerim Serbest Serdar Karab?cek Saadettin Güner 《Monatshefte für Chemie / Chemical Monthly》2004,15(4):1023-1031
Nucleolytic activities of novel mononuclear Cu(II), homo- and heterodinuclear Cu(II)–Ni(II) complexes with two diester-type ligands were investigated on pCYTEXP by neutral agarose gel electrophoresis. The analyses of the cleavage products obtained electrophoretically indicate that the examined complexes induce very similar conformational changes on supercoiled DNA by converting supercoiled form to nicked form. At concentrations greater than 100M, the complexes possessed effective nucleolytic activities for 10min of incubation time. However, their nucleolytic activities did not increase significantly with longer periods of incubation. The pH-nucleolytic activity profiles of the complexes differed significantly. Metal complex induced DNA cleavage was also tested for inhibition by various radical scavengers. It could be proposed from the data that diffusible intermediate oxidants are not involved in these reactions or they are not necessary for DNA cleavage since none of antioxidants inhibited DNA cleaving activities of the complexes. 相似文献
2.
Aye Ogan Baak Yüce‐Dursun Deka Abdullah Asl Beyler‐iil Memet Vezir Kahraman Pnar alayan Meral Birbir
zal Mutlu Nagihan Gülsoy 《先进技术聚合物》2020,31(10):2222-2228
The use of biopolymers has gained priority in tissue engineering and biotechnology, both as dressing material and for enhancing treatment efficiency. There is a demand for new biopolymers designed with protease inhibitors and antimicrobials. LL‐37 is an important antimicrobial peptide in human skin and exhibits a broad spectrum of antimicrobial activity against bacteria, fungi, and viral pathogens. Using lignin which is an abundant carbohydrate polymer in nature and a polyacrylic acid, we prepared a lignin/caprolactone biodegradable film by plastifying caprolactone and polyacyrlic acid. Lignin/caprolactone biodegradable film was activated with CDI and then immobilized LL‐37 peptide. The structure was elucidated in terms of its functional groups by attenuated total reflectance‐fourier transform infrared spectroscopy (ATR‐FTIR), and the morphology of the lignin/caprolactone biodegradable film was characterized by scanning electron microscopy (SEM) before and after the immobilization process. The amount of LL‐37 immobilized was determined by ELISA method. It was found that 97% of LL‐37 peptide was successfully immobilized onto the lignin/caprolactone biodegradable film. Antimicrobial activity was determined in the lignin/caprolactone biodegradable film samples by quantitative antimicrobial activity method. According to the results, LL‐37 immobilized lignin/caprolactone biodegradable film samples were effective on test organisms; Gram‐positive Staphylococcus aureus and Gram‐negative Escherichia coli. In bio‐compatibility assays, the ability to support tissue cell integration was detected by using 3 T3 mouse fibroblasts. Samples were examined under transverse microscope, non‐immobilized sample showed a huge cellular death, whereas LL‐37 immobilized lignin/caprolactone biodegradable film had identical cellular growth with the control group. This dual functional lignin/caprolactone biodegradable film with enhanced antibacterial properties and increased tissue cell compatibility may be used to design new materials for various types of biological applications. 相似文献
3.
We retrospectively reviewed MR studies on 10 patients with renal-related perinephric fluid collections who underwent MRI in three institutions between January 2001 and August 2004. All patients underwent MRI of the abdomen and T1-weighted, T2-weighted and serial contrast-enhanced images, including delayed-phase contrast-enhanced images 10-12 min after contrast injection, were obtained. Perinephric fluid collections in 5 patients revealed MRI findings of simple fluid content (i.e., hypointense on T1-weighted images and hyperintense on T2-weighted images). In another 5 patients, a complex perinephric fluid content (i.e., mixed hyper/hypointense on T1-weighted images and mixed hypo/hyperintense on T2-weighted images compatible with blood breakdown products and pus) was observed. In 5 patients, contrast extravasation on late-phase images that was compatible with urine leak was demonstrated. Our results suggest that MRI may determine the content of perinephric fluid collections on noncontrast T1-weighted and T2-weighted images and that contrast extravasation on late-phase images is associated with urine extravasation from renal collecting systems. 相似文献
4.
Mehmet Yaman 《光谱学与光谱分析》2013,32(5):1331-1337
The aim of this study is to examine seasonal changes in Cu and Co concentrations of three plant species for monitoring the effects of pollution in Elazig,Turkey.For this purpose,the leaves of the Pinus nigra L.,Cedrus libani and Cupressus arizonica together with soil samples were collected from different points depending on traffic intensity,nearness the city center and cement factory as well as control location during different months of the year.Flame atomic absorption spectrophotometer(FAAS) was used for measurement of the metals in clear digests after the dry ashing method.Copper and Co concentrations were in the ranges from 1.3to 2.6mg.kg-1 and相似文献
5.
4,4,6,6‐Tetrachloro‐2,2‐(ethylenedioxydi‐o‐phenylenediimino)‐2λ5,4λ5,6λ5‐cyclotriphosphazene
Nagihan aylak Tuncer Hkelek Selen Bilge Bilgehan
zgü Zeynel Kl 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(7):o461-o463
The title ligand, C14H14Cl4N5O2P3, is a cyclophosphazene lariat (PNP pivot) ether with a spiro‐cyclic 11‐membered macrocyclic ring containing two ether O and two N atoms; the phosphazene ring is nearly planar. The macrocyclic ring contains a four‐centred (trifurcate) N—H⋯O/N—H⋯N hydrogen bond, and the relative inner‐hole size of the macrocycle is ∼1.14 Å in radius. The molecules are linked about inversion centres by N—H⋯N hydrogen bonds into centrosymmetric dimers. 相似文献
6.
Ahmet Colak Ender Cekirge Serdar Karaböcek Aslıgül Küçükdumlu Nagihan Sağlam Ertunga Melek Col Rza Abbasoğlu 《Chemical Papers》2009,63(5):554-561
Nucleolytic activities of some new oxime-type ligand complexes were investigated by neutral agarose gel electrophoresis. Analysis
of the cleavage products in agarose gel indicated that all complexes used converted supercoiled pUC18 plasmid DNA to its nicked
or linear form. It was found that nucleolytic activities of the complexes depend on the complex concentration, reaction time
and the presence of a cooxidant (magnesium monoperoxyphthalate, MMPP) in the reaction mixture. However, the complexes cleaved
pUC18 plasmid DNA at all investigated pH values. Nucleolytic activities of complexes were investigated for different complex
concentrations (0.1–100 μmol L−1), pH values (6.0–10.0) and reaction times (0–60 min). Molecular modeling studies performed by the Hyperchem Software together
with DNA-binding studies showed that planar sites of the complexes intercalated into double stranded DNA. It can be concluded
that all oxime-type ligand complexes used can be evaluated as nuclease mimics. 相似文献
7.
Elif Şenkuytu Hande Eserci Nagihan Bayık Nadide Akbaş Elif Okutan Gönül Yenilmez Çiftçi 《Phosphorus, sulfur, and silicon and the related elements》2020,195(7):570-579
AbstractIn this study, five new paraben substituted cyclotriphosphazene compounds containing hydrophilic glycol groups were successfully synthesized. All synthesized cyclotriphosphazene compounds 1-10 were fully characterized via general spectroscopic techniques such as 1H, 31P NMR and MALDI-TOF mass spectrometry. In addition, the investigations of the UV-vis absorption and fluorescence emission properties of the 1-10 carried out via absorption and fluorescence spectroscopies in different solvents. The absorbance bands of the all synthesized compounds 1-10 were observed at about 230–300?nm in all solvents studied. Furthermore, the highest fluorescence emission intensity of the compounds 1-10 was observed in tetrahydrofuran at about 312?nm and the lowest emission intensity was observed in chloroform. The synthesized molecules can be used as custom designed molecules to investigate the DNA binding properties in automatic biosensor device in our laboratories, since they carry hydrophilic glycol units for water solubility and paraben derivatives for DNA effecting properties. 相似文献
8.
Murat Aydemir Akın Baysal Nevin Gürbüz İsmail Özdemir Bahattin Gümgüm Saim Özkar Nagihan Çaylak Leyla Tatar Yıldırım 《应用有机金属化学》2010,24(1):17-24
Three new (N‐diphenylphosphino)‐isopropylanilines, having isopropyl substituent at the carbon 2‐ (1) 4‐ (2) or 2,6‐ (3) were prepared from the aminolysis of chlorodiphenylphosphine with 2‐isopropylaniline, 4‐isopropylaniline or 2,6‐diisopropylaniline, respectively, under anaerobic conditions. Oxidation of 1,2 and 3 with aqueous hydrogen peroxide, elemental sulfur or gray selenium gave the corresponding oxides, sulfides and selenides (Ph2P?E)NH? C6H4? 2‐CH(CH3)2, (Ph2P?E)NH? C6H4? 4‐CH(CH3)2 and (Ph2P?E)NH? C6H4? 2,6‐{CH(CH3)2}2, where E = O, S, or Se, respectively. The reaction of [M(cod)Cl2] (M = Pd, Pt; cod = 1,5‐cyclooctadiene) with two equivalents of 1,2 or 3 yields the corresponding monodendate complexes [M((Ph2P)NH? C6H4? 2‐CH(CH3)2)2Cl2], M = Pd 1d, M = Pt 1e, [M((Ph2P)NH? C6H4? 4‐CH(CH3)2)2Cl2], M = Pd 2d, M = Pt 2e and [M((Ph2P)NH? C6H4? 2,6‐(CH(CH3)2)2)2Cl2], M = Pd 3d, M = Pt 3e, respectively. All the compounds were isolated as analytically pure substances and characterized by NMR, IR spectroscopy and elemental analysis. Furthermore, representative solid‐state structure of [(Ph2P?S)NH? C6H4? 4‐CH(CH3)2] (2b) was determined using single crystal X‐ray diffraction technique. The complexes 1d–3d were tested and found to be highly active catalysts in the Suzuki coupling and Heck reaction, affording biphenyls and stilbenes, respectively. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
9.
Merve Tuzlakoglu Ozturk Nagihan Akbulut Saliha Issever Ozturk Fusun Gumusel 《Applied biochemistry and biotechnology》2013,171(2):263-278
Five hundred ninety-seven bacterial isolates from Turkish hot spring water sources were screened for their ability to produce extracellular α-amylase. Among them, a high enzyme-producing Bacillus subtilis isolate, A28, was selected, and its α-amylase gene was cloned and expressed in Escherichia coli by a ligase-independent method. α-Amylase from the recombinant strain was purified to homogeneity by Q-Sepharose anion exchange and Sephacryl S-100 gel filtration chromatographies. The final yield of the enzyme was about 22.5 % of the initial activity, with a 16.4-fold increase in specific activity compared with the culture lysate. The optimum temperature and pH of the enzyme were 70 °C and 6.0, respectively. The enzyme was highly active at acidic-neutral pH range of 4.5–7.0. The amy28 α-amylase retained 100 % of its activity after incubation at 50 °C for 90 min. Co+2, Cu2+, Fe2+, Fe3+, Ni+2, and Zn+2 caused significant inhibition in enzyme activity, which was not affected by Na+, Mg2+, Li+, and Ba2+. The activity was inhibited about 70 % upon treatment of the enzyme with 10 mM ethylenediaminetetraacetic acid. However, Ca2+ ions known as high temperature stabilizer for other amylases did not stimulate the activity of the enzyme. Due to pH stability and thermostability of the recombinant amylase, this enzyme may be suitable in starch processing, brewing, and food industries. 相似文献
10.
Zeynel Kılıç Aytuğ Okumuş Şemsay Demiriz Selen Bilge Aslı Öztürk Nagihan Çaylak Tuncer Hökelek 《Journal of inclusion phenomena and macrocyclic chemistry》2009,65(3-4):269-286
The condensation reactions of N2O3-donor type coronands (1–3) with hexachlorocyclotriphosphazatriene, N3P3Cl6, resulted in the formation of spiro-crypta phosphazene derivatives (4–6). These compounds with excess morpholine and 1,4-dioxa-8-azaspiro[4,5]decane (DASD) afford fully substituted morpholino (7 and 10) and 1,4-dioxa-8-azaspiro[4,5]deca (8)-substituted phosphazene derivatives, respectively. Whilst, in the same conditions, the reactions of 4, 5 and 6 with pyrrolidine, morpholine and DASD also produce partially pyrrolidino-substituted geminal (9 and 11), mono-substituted pyrrolidino (12), morpholino (13) and 1,4-dioxa-8-azaspiro[4,5]deca (14) phosphazenes. It has been clearly observed that the chloride replacement reactions of 4, 5 and 6 with pyrrolidine lead to the geminal products. Compounds 7, 8 and 10 are the first examples of anisochronic tetrakis (amino) phosphazenes according to 31P NMR data. The structures of 7, 8 and 10–14 have been determined by FTIR, MS, 1H, 13C and 31P NMR, DEPT, and HETCOR spectral data. The solid-state structures of 9, 13 and 14 have been examined by X-ray diffraction techniques. The sums of the bond angles around the spiro cyclic nitrogen atoms [344.8(4)° and 347.6(4)°] of 9, indicate that the nitrogen atoms have pyramidal geometries. Thus, the N atoms seem to have stereogenic configurations. Compounds 12–14 also have two stereogenic P-atoms, and they are expected to be in the mixture of enantiomers. The relationships between NPN (α and α′) bond angles and δPspiro values and the correlation of Δ(P–N) with δPspiro and Δ(δP) values are presented. 相似文献