67 research outputs found
Current Treatment of Endolymphatic Sac Tumor of the Temporal Bone
An endolymphatic sac tumor (ELST) is a rare, indolent but locally aggressive tumor arising in the posterior petrous ridge. Patients present with sensorineural hearing loss and tinnitus. As the tumor progresses, patients may experience vertigo, ataxia, facial nerve paresis, pain and otorrhea. Most patients present in their 4th or 5th decade with a wide age range. Patients with von Hippel–Lindau disease have an increased likelihood of developing ELST. Histologically, ELST is a low-grade adenocarcinoma. As it progresses, it destroys bone and extends into adjacent tissues. The likelihood of regional or distant metastases is remote. The optimal treatment is resection with negative margins. Patients with positive margins, gross residual disease, or unresectable tumor are treated with radiotherapy or radiosurgery. Late recurrences are common, so long follow-up is necessary to assess efficacy. The likelihood of cure depends on tumor extent and is probably in the range of 50–75%
Effect of sitagliptin on cardiovascular outcomes in type 2 diabetes
BACKGROUND: Data are lacking on the long-term effect on cardiovascular events of adding sitagliptin, a dipeptidyl peptidase 4 inhibitor, to usual care in patients with type 2 diabetes and cardiovascular disease. METHODS: In this randomized, double-blind study, we assigned 14,671 patients to add either sitagliptin or placebo to their existing therapy. Open-label use of antihyperglycemic therapy was encouraged as required, aimed at reaching individually appropriate glycemic targets in all patients. To determine whether sitagliptin was noninferior to placebo, we used a relative risk of 1.3 as the marginal upper boundary. The primary cardiovascular outcome was a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for unstable angina. RESULTS: During a median follow-up of 3.0 years, there was a small difference in glycated hemoglobin levels (least-squares mean difference for sitagliptin vs. placebo, -0.29 percentage points; 95% confidence interval [CI], -0.32 to -0.27). Overall, the primary outcome occurred in 839 patients in the sitagliptin group (11.4%; 4.06 per 100 person-years) and 851 patients in the placebo group (11.6%; 4.17 per 100 person-years). Sitagliptin was noninferior to placebo for the primary composite cardiovascular outcome (hazard ratio, 0.98; 95% CI, 0.88 to 1.09; P<0.001). Rates of hospitalization for heart failure did not differ between the two groups (hazard ratio, 1.00; 95% CI, 0.83 to 1.20; P = 0.98). There were no significant between-group differences in rates of acute pancreatitis (P = 0.07) or pancreatic cancer (P = 0.32). CONCLUSIONS: Among patients with type 2 diabetes and established cardiovascular disease, adding sitagliptin to usual care did not appear to increase the risk of major adverse cardiovascular events, hospitalization for heart failure, or other adverse events
Derivatives of benzo[b]furan. Part I. Conformational studies of khellinone and visnaginone
A three-dimensional lead(II) polymer with bridging saccharinate and unusually coordinated acetate ligands - Synthesis, IR spectra, and crystal structure of [Pb(H2O)(mu-OAc)(mu-sac)](n)
Andac, Omer/0000-0003-3641-9690; Yilmaz, Veysel/0000-0002-2849-3332;WOS: 000182160800025The complex [Pb(H2O)(mu-OAc)(mu-sac)]n with acetate (OAc) and saccharinate (sac) ligands was characterized by IR, elemental analysis and X-ray crystallography The mixed-anion lead(II) complex crystallizes in the triclinic crystal system with the space group of P1. The single crystal X-ray analysis shows that the complex is a coordination polymer in which the lead(II) ions have a highly distorted pentagonal bipyramidal coordination geometry. Lead(II) ions are bridged by carboxylate groups in a zigzag arrangement forming one-dimensional infinite chains, which are also linked by sac bridges and aromatic pi-pi contacts between the adjacent phenyl rings of sac ligands, resulting in a three-dimensional network. One water molecule coordinates the lead(II) ion and also forms weak hydrogen bonds with the sulfonyl oxygen atoms of the neighboring sac ligands. The sac ligand acts as a bridging ligand through the nitrogen and carbonyl oxygen atoms, while the carboxylate moiety of the acetate ligand shows an unusual (bidentate, and bridging) coordination behaviour, which was observed for the first time in the structure
Synthesis, Characterization, Crystal Structures and Thermal and Fluorescence Studies of Dinuclear and Polymeric Silver(I) Complexes of 5,5-Diethylbarbiturate with 2,5-Dimethylpyrazine and Piperazine Involving Ag–Ag Interactions
Crystal structure and physico-chemical properties of diaquabis(1,10-phenanthroline)manganese(II) disaccharinate monohydrate
TOPCU, YILDIRAY/0000-0002-2095-6603; Andac, Omer/0000-0003-3641-9690; Yilmaz, Veysel/0000-0002-2849-3332; YILMAZ, Fatih/0000-0002-7711-0975WOS: 000167079800002A novel manganese complex, [Mn(phen)(2)(H2O)(2)](sac)(2).H2O, was synthesized by the reaction of [Mn(sac)(2)(H2O)(4)]. 2H(2)O with 1,10-phenantroline in aqueous solution and characterized by elemental analysis, IR spectral evidence, magnetic measurements, thermal analysis and single crystal X-ray diffraction. The compound crystallizes in triclinic system, space group P-1, with Z = 2. The saccharinate ions do not coordinate the central metal, instead are present as the complementary anions. In the complex cation, Mn(II) is coordinated by two phen and two aqua ligands, and exhibits a distorted octahedral coordination with a high-spin configuration. The presence of lattice and coordinate water molecules are also confirmed by thermal analysis and IR spectroscopy. (C) 2001 Elsevier Science B.V. All rights reserved
Crystal and molecular structure of 3-phenyl-4-(p-chlorobenzlyamino)-4,5-dihydro-1-H-1,2,4-triazol-5-on
Yilmaz, Veysel/0000-0002-2849-3332WOS: 000223853900011The structure of the title compound, C15H13N4OCl was determined by single crystal X-ray diffraction technique. The structure consists of a p-chlorobenzylamino moiety and triazol and phenyl rings. The title compound crystallizes in the monoclinic space group P2(1)/c with a = 14.368(3), b = 6.255(3), c = 17.631(3) Angstrom, beta = 113.24(3)degrees, Z = 4, V = 1455.8(8) Angstrom(3) and D-x = 1.372 gcm(-3). The structure was solved by direct methods and refined by full-matrix least-squares method (R=0.0477). The dihedral angle between the triazole moiety and the phenyl ring is 28.8(3)degrees. The molecular packing is stabilized by N-(HN)-N-... and N-(HO)-O-... types of inter molecular hydrogen bonds
Three 1,2,4-triazole derivatives containing subtituted benzyl and benzylamino groups
Kazak, Canan/0000-0003-2475-8775; Yilmaz, Veysel/0000-0002-2849-3332WOS: 000227376600038PubMed: 15695905The title compounds, 4-benzylamino-3-(4-methylbenzyl)-1-H1,2,4-triazol-5 (4M-one, C17H18N4O, (I), 3-(4-methylbenzyl)4- (4-methylbenzylamino) -1H-1,2,4-triazol-5 (4H) -one, C18H20N4O, (II), and 3-(4-chlorobenzyl)-4-(4-methylbenzylamino)-1H-1,2,4-triazol-5 (4H) -one, C17H17ClN4O, (III), were obtained from the corresponding Schiff base in the presence of diglyme and NaBH4. Each compound contains a 1,2,4-triazole ring and two benzene rings, which are essentially planar. The molecules are linked by a combination of intermolecular NH...O and N-H...N hydrogen bonds. Additionally, there is a weak pi-pi stacking interaction in (I), involving the benzene ring of the aminobenzyl group and the partially aromatic 1,2,4-triazole moiety, with a centroid-centroid distance of 3.7397 (10) Angstrom
Distribution of uranium in the production of triple superphosphate (TSP) fertilizer and phosphoric acid
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