Preparation and characterization of polyacrylonitrile membranes modified with polyelectrolyte deposition for separating similar sized proteins

One of the challenges faced by ultrafiltration membranes is to separate proteins with a small difference in their molecular weights. Recently, some researchers tried to overcome this problem by using charged membranes. This study examined the use of layer by layer deposition of polyelectrolytes on the chemically-modified polyacyronitrile membrane to increase the selectivity of the ultrafiltration. The membranes were prepared by wet-phase inversion technique and polyethylenimine (PEI) and alginate (ALG) were chosen as cationic and anionic polyelectrolytes for the modification of the surfaces. Sieving coefficient data were obtained with myoglobin and lysozyme as model proteins. The influences of solution pH, ionic strengths of the protein and polyelectrolyte solution and the number of polyelectrolyte bilayers on both selectivity and throughput were investigated. The highest selectivity and throughput were achieved with the 1-bilayer PEI-ALG coated polyacrylonitrile (PAN) membrane. Increasing the number of coating bilayers or the ionic strength of the protein solution or adding salt into the polyelectrolyte coating solution decreased both the maximum selectivity and throughput of the modified membranes.Izmir Institute of Technology; 2009IYTE0

The effects of coenzyme Q10 (CoQ10) on Ionizing radiation- induced pancreatic β-cell injury

Objective: This study investigated the antioxidant effect of coenzyme Q10 on ionizing radiation induced oxidative damage in pancreatic & beta;-cells. Methods: Twenty-four male rats were assigned to 4 groups. Group 1 constituted the control group, Group 2 only received a single i.p. dose of coenzyme Q10, Groups 3 and 4 received a total of 4 Gy external x-ray radiation to the abdomen in a single fraction. Group 4 also received a single dose of 200 mg/kg coenzyme Q10 i.p. 30 minutes prior to x-ray irradiation. Results:The x-ray radiation group showed decreased & beta;-cell positivity in the islets of Langerhans compared to the control group on immunohistochemical analysis. In contrast, an increase in & beta;-cells exhibiting insulin positivity was observed in group 4 (ionizing radiation + coenzyme Q10) compared to the irradiation group. Terminal deoxynucleotidyl transferase dUTP nick end labeling assay indicated a rise in the number of apoptotic cells in the x-ray radiation group compared to the control and coenzyme Q10-only groups (Group 2). Meanwhile, we observed a decrease in the number of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive apoptotic cells in the islets of Langerhans in the ionizing radiation + coenzyme Q10 treatment group (Group 4) relative to the irradiation group. Conclusion: This study shows that coenzyme Q10 reduces apoptosis in the rat pancreas exposed to abdominal ionizing radiation

Tetra­aqua­bis(isonicotinamide-κN 1)cobalt(II) bis­(4-formyl­benzoate) dihydrate

The asymmetric unit of the crystal structure of the title complex, [Co(C6H6N2O)2(H2O)4](C8H5O3)2·2H2O, contains one-half of the complex cation with the CoII ion located on an inversion center, a 4-formyl­benzoate (FB) counter-anion and an uncoordinated water mol­ecule. The four O atoms in the equatorial plane around the CoII ion form a slightly distorted square-planar arrangement with an average Co—O bond length of 2.086 Å; the slightly distorted octa­hedral coordination is completed by the two N atoms of the isonicotinamide (INA) ligands at a slightly longer distance [2.1603 (14) Å] in the axial positions. The dihedral angle between the carboxyl­ate group and the attached benzene ring is 5.93 (13)°, while the pyridine and benzene rings are oriented at a dihedral angle of 3.09 (6)°. In the crystal structure, O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds link the mol­ecules into a three-dimensional network. π–π Contacts between the benzene and pyridine rings [centroid–centroid distance = 3.758 (1) Å] may further stabilize the crystal structure

Aqua­bis(4-formyl­benzoato-κ2 O 1,O 1′)bis­(isonicotinamide-κN 1)cadmium(II) monohydrate

The asymmetric unit of the title CdII complex, [Cd(C8H5O3)2(C6H6N2O)2(H2O)]·H2O, contains two 4-formyl­benzoate (FB), two isonicotinamide (INA) ligands, one coordinated and one uncoordinated water mol­ecule; the FB ions act as bidentate ligands. The coordination number of the Cd(II) atom is seven within a CdO5N2 donor set. Intra­molecular O—H⋯O hydrogen bonds link the uncoordinated water mol­ecules to the carboxyl groups. The dihedral angle between the carboxyl­ate groups and the adjacent benzene rings are 17.53 (13) and 16.55 (14)°. In the crystal structure, inter­molecular O—H⋯O, N—H⋯O, N—H⋯N and C—H⋯O hydrogen bonds link the mol­ecules into a supra­molecular structure. The amide group of one of the INA ligands is disordered over two orientations, with an occupancy ratio of 0.759 (3):0.241 (3)

Tetra­kis[μ-4-(methyl­amino)­benzoato-κ2 O:O′]bis­[(N,N-diethyl­nicotinamide-N 1)zinc(II)] dihydrate

The title mol­ecule, [Zn2(C8H8NO2)4(C10H14N2O)2]·2H2O, is a centrosymmetric binuclear complex, with two ZnII ions [Zn⋯Zn’ = 2.9301 (4) Å] bridged by four methyl­amino­benzoate (MAB) ligands. The four nearest O atoms around each ZnII ion form a distorted square-planar arrangement with the distorted square-pyramidal coordination completed by the pyridine N atom of the N,N-diethyl­nicotinamide (DENA) ligand. Each ZnII ion is displaced by 0.3519 (2) Å from the plane of the four O atoms, with an average Zn—O distance of 2.030 Å. The dihedral angles between carboxyl­ate groups and adjacent benzene rings are 10.57 (10) and 16.63 (12)°, while the benzene rings are oriented at a dihedral angle of 81.84 (5)°. The pyridine ring is oriented at dihedral angles of 40.49 (6) and 51.25 (6)° with respect to the benzene rings. In the crystal structure, inter­molecular O—H⋯O and N—H⋯O hydrogen bonds link the mol­ecules into a three-dimensional network. The π–π contact between the inversion-related pyridine rings [centroid–centroid distance = 3.633 (1) Å] may further stabilize the crystal structure

Tetra­aqua­bis(isonicotinamide-κN 1)nickel(II) bis­(4-formyl­benzoate) dihydrate

The asymmetric unit of the title complex, [Ni(C6H6N2O)2(H2O)4](C8H5O3)2·2H2O, contains one-half of the complex cation with the NiII atom located on an inversion center, a 4-formyl­benzoate (FB) counter-anion and an uncoordinated water mol­ecule. The four O atoms in the equatorial plane around the Ni atom form a slightly distorted square-planar arrangement and the slightly distorted octa­hedral coordination is completed by the two N atoms of the isonicotinamide (INA) ligands at a sligthly longer distance in the axial positions. The dihedral angle between the carboxyl­ate group and the attached benzene ring is 8.14 (11)°, while the pyridine and benzene rings are oriented at a dihedral angle of 3.46 (6)°. In the crystal structure, O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds link the mol­ecules into a three-dimensional network. π–π Contacts between the benzene and pyridine rings [centroid–centroid distance = 3.751 (1) Å] may further stabilize the crystal structure

Halkla İlişkiler Araştırmalarında Yeni İletişim Teknolojilerinin Kullanımı: Halkla İlişkiler Ajanslarında Çevrimiçi Araştırma Tekniklerinin Kullanımına Yönelik Bir Araştırma

Öz Gelişen teknoloji ile birlikte hayatımızın her alanında ilerlemelerin kaydedildiği bilinmektedir. Bu ilerlemelerin kaynağını oluşturan internet sayesinde birçok yeni ortam, araç ve mecra geliştirilmiştir. Bu ortam ve araçlar hayatımızın her alanında başvurduğumuz vazgeçilmez unsurlar haline gelmiştir. Bu alanlardan birisi de her çalışmada yapılması gereken, bilinmeyenlere ışık tutan araştırmalardır. Herhangi bir alanda yapılan araştırmalarda önceden sadece geleneksel teknik ve araçlardan söz edilirken, yeni iletişim teknolojilerinin sunduğu ortam, araç ve tekniklerle çevrimiçi teknik ve araçlardan söz edilmeye başlanmıştır. Bu gelişmelerle araştırmalar dijital boyut kazanmış ve yapısı oldukça değişmiştir. Bu çalışma, gelişen teknolojiyle birlikte ortaya çıkan yeni iletişim teknolojilerinin sunduğu olanakların araştırmalarda kullanımını ve etkilerini incelemenin yanı sıra geleneksel araştırma tekniklerinin de kullanımını ortaya koymak amacıyla gerçekleştirilmiştir. Türkiye’de yer alan halkla ilişkiler ajansları evreni oluşturmuştur. Türkiye Halkla İlişkiler Derneği’ne (TÜHİD) bağlı ajansların 57 tanesinin İstanbul’da, birinin İzmir’de, diğerinin Gaziantep’te yer alması nedeniyle çalışma evreni İstanbul’daki halkla ilişkiler ajansları olarak belirlenmiştir. Bu ajanslarla mülakat tekniği kullanılarak yüz yüze görüşmeler yapılmış, sonuçlar tablolar halinde yorumlanmıştır

Bis(μ-2-fluoro­benzoato-1:2κ2 O:O′)(2-fluoro­benzoato-1κ2 O,O′)(2-fluoro­benzoato-2κO)dinicotinamide-1κN 1,2κN 1-dizinc(II)–2-fluoro­benzoic acid (1/1)

The asymmetric unit of the title compound, [Zn2(C7H4FO2)4(C6H6N2O)2]·C7H5FO2, consists of a binuclear ZnII complex bridged by two carboxyl groups of 2-fluoro­benzoate (FB) anions and a 2-fluoro­benzoic acid mol­ecule. The two bridging FB anions, one chelating FB anion and one nicotinamide (NA) ligand coordinate to one Zn cation with a distorted square-pyramidal geometry, while the two bridging FB anions, one monodentate FB anion and one NA ligand coordinate to the other Zn cation with a distorted tetra­hedral geometry. Within the binuclear mol­ecule, the pyridine rings are oriented at a dihedral angle of 19.41 (14)°. In the crystal structure, the uncoordinated 2-fluorobenzoic acid mol­ecules are linked by O—H⋯O hydrogen bonding, forming centrosymmetric supra­molecular dimers. Inter­molecular N—H⋯O hydrogen bonds link the complex mol­ecules into a three-dimensional network. The π–π contacts between nearly parallel pyridine and benzene rings [dihedral angles of 19.41 (14) and 12.72 (16)°, respectively, centroid–centroid distances = 3.701 (2) and 3.857 (3) Å] may further stabilize the crystal structure. The fluorine atoms in two FB ligands are disordered over two positions, with occupancy ratios of 0.70:0.30

Diaqua­bis(2-bromo­benzoato-κO)bis­(N,N-diethyl­nicotinamide-κN 1)nickel(II)

In the monomeric centrosymmetric title NiII complex, [Ni(C7H4BrO2)2(C10H14N2O)2(H2O)2], the NiII ion is located on an inversion center. The asymmetric unit contains one 2-bromo­benzoate ligand, one diethyl­nicotinamide (DENA) ligand and one coordinated water mol­ecule. The four O atoms in the equatorial plane around the NiII ion form a slightly distorted square-planar arrangement, while the slightly distorted octa­hedral coordination is completed by two N atoms of two DENA ligands in the axial positions. The dihedral angle between the benzene ring and the attached carboxyl­ate group is 87.73 (15)°, while the pyridine and benzene rings are oriented at a dihedral angle of 42.48 (7)°. In the crystal structure, O—H⋯O hydrogen bonds link the mol­ecules into a two-dimensional network parallel to (10). In addition, C—H⋯O hydrogen bonds are observed

Spinal cord stimulation in failed back surgery

Objective: Spinal cord stimulation is used for treating failed back surgery syndrome, chronic arachnoiditis, peripheral neuropathies, postamputation phantom pain, complex regional pain syndrome and pain secondary to spinal cord injury. In this study we present 7 cases with intractable neuropathic radicular pain which developed following spine surgery. Material and Methods: Spinal cord stimulation was applied to 7 (3male/4 female) patients who had failed back surgery syndrome and pain resistant to medical and invasive methods, with the council decision, which included neurosurgery, neurology, and psychiatry. One week stimulation trial was applied to all cases. Results:The mean age of the patients was 54.85±7.64 years. The mean of pain intensity in Visual Analog Scale was 8.71±0.74 at preoperative status and post operative pain intensity was 2.27±0.67 at 6 months. Pain intensity significantly decreases after spinal cord stimulation (p=0.000). One of the three cases who had unsuccessful trial period received morphine pump implantation, and percutaneous lumbar sympathectomy was applied to another one. One case who received permanent implantation was replaced to another location due to skin erosion. There was no morbidity. Conclusion: Spinal cord stimulation is an effective tool in reducing pain, in patients who have unsuccessful lower back surgery with the correct indications