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Herein a novel polymeric adsorbent composite material was introduced for the adsorption of methylene blue from aqueous solutions for the purpose of water treatment. Adsorption process was examined by using Langmuir and Freundlich isotherm models together with pseudo-first and second order kinetic analysis. It was found that characteristic of the adsorption process was well described by Langmuir isotherm following pseudo-first order kinetic route. The maximum monolayer adsorption capacity was determined as 49.04 mg g−1. In light of thermodynamic parameters of the adsorption and removal of MB from the composite in acidic solution suggested that the process was based on ion-exchange mechanism. Negative values of Gibbs free energies changing from − 5.41 to − 15.99 kJ mol−1 with increasing temperature demonstrated that adsorption process occurs spontaneously. Heat of adsorption and entropy values were found as 58.30 kJ mol−1 and 0.23 kJ mol K−1, respectively. Therefore, adsorption process was endothermic in nature without noticeable disorder. The material consisting of functionalized poly(methyl methactrylate) in the polyvinylidene fluoride–hexafluoropolypropylene matrix is considered to be a potential adsorbent material for the treatment of polluted waters. [ABSTRACT FROM AUTHOR]

Key exchange algorithms such as the Diffie-Hellman method are used to determine a common secret key which will be used in symmetric key algorithms in cryptography. In this paper, we give a key exchange algorithm which includes some steps of Diffie-Hellman method by using algorithms of the topological basic concepts such as subbase, base and topology. [ABSTRACT FROM AUTHOR]

The paper focuses on a series of blends prepared with different contents of polystyrene-block-poly-(ethylene-ranbutylene)- block-polystyrene (SEBS) and polypropylene (PP) for the purpose of examining the potential as proton exchange membranes. Polymer blends were prepared by twin-screw extrusion and then compressed by means of a hot-press device into thin films of 125 μm and then ionic sides were created by solid state sulfonation in a chlorosulfonic acid solution. Obtained films were characterized by means of water-uptake, mechanical properties, ion-exchange capacities (IEC) and ion conductivities. It was observed that the rigidity of the films increased with rising sulfonation durations. However humidity absorption from the air decreased the rigidity at high sulfonation levels. Improved water uptake values were obtained when compared to previously reported values in the literature. On the other hand ion exchange values showed an increase parallel to the sulfonation duration up to 45 minutes, but a decrease thereafter was observed due to the diffusion of some sulfonated polymer chains into the ion-exchange medium thereby calculated ion exchange values of S-SEBSH45 and S-SEBSH60 were found less than expected. All films showed ion conductivities up to 432 mS/cm at 25 °C. Only S-SEBSH45 and S-SEBSH60 were successful in conducting protons at 80 °C owing to the high water retaining capacity. [ABSTRACT FROM AUTHOR]

Copyright of Turkish Journal of Medical Sciences is the property of Scientific and Technical Research Council of Turkey and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Turkish Journal of Medical Sciences is the property of Scientific and Technical Research Council of Turkey and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Turkish Journal of Medical Sciences is the property of Scientific and Technical Research Council of Turkey and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Hydatid cyst (HC) continues to be endemic in the Mediterranean countries, such as Turkey. Living in a rural area is an important risk factor for the disease. HC is most commonly seen in the liver and lungs, but retroperitoneal hydatid cyst is very rare. The objective of this study was to evaluate the clinical and radiographic findings and surgical treatment of this unusual lesion. Methods: Between 1979 and 2004, 14 cases with primary retroperitoneal hydatid cyst were treated surgically at our clinic. Results: Symptoms included flank pain in eight (57.1%) and palpable mass in six patients (42.8%). The cyst was located in the right retroperitoneum in seven patients (50%), left retroperitoneum in five patients (35.7%), retrovesical region in one patient (7.1%) and paravesical region in one patient (7.1%). Surgical approaches were right paramedian extraperitoneal approach in four patients, left paramedian extraperitoneal approach in two patients and midline transperitoneal approach in eight patients. Total pericystectomy was chosen as the surgical procedure in all patients except in five (35.7%), who had partial cystectomy for cysts located near the vital structures. There were no complications and mortality postoperatively. Conclusion: A primary HC of the retroperitoneum is a distinct clinical entity that must be considered when caring for a patient with a retroperitoneal mass in endemic regions. It should be treated after the diagnosis is confirmed without any delay because of secondary spillages due to perforations and other possible complications. [ABSTRACT FROM AUTHOR]

Copyright of Turkish Journal of Medical Sciences is the property of Scientific and Technical Research Council of Turkey and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study was designed to review the outcomes of emergent treatment of sigmoid colon volvulus. The records of 827 patients were reviewed retrospectively. The mean age was 57.9 years (range, 10 weeks to 98 years), and 688 patients (83.2 percent) were male. Nonoperative reduction was applied in 575 patients (barium enema in 13, rigid sigmoidoscopy in 351, and flexible sigmoidoscopy in 211, with rectal tube placement in all patients). The results were as follows: success of 78.1 percent, mortality of 0.9 percent, complication of 3 percent, and early recurrence of 3.3 percent. Surgical treatment was performed on 393 patients (detorsion in 46, mesosigmoidopexy in 56, exteriorization in 4, resection with Hartmann’s procedure in 146, resection with Mikulicz procedure in 14, resection with primary anastomosis in 51, tube cecostomy and colonic cleansing with resection in 75, and laparotomy in 1). The results were as follows: mortality of 15.8 percent, complication of 37.2 percent, early recurrence of 0.8 percent, and late recurrence of 6.7 percent. Nonoperative reduction is the initial treatment of sigmoid colon volvulus, and flexible sigmoidoscopy with rectal tube placement can be used successfully. Patients in whom bowel gangrene or peritonitis is present or nonoperative treatment is unsuccessful need emergency surgery. In surgical treatment, resection and primary anastomosis is the first choice, and it can be performed with acceptable mortality and morbidity rates if the patient is stable and a tension-free anastomosis is possible. Nondefinitive procedures have high recurrence rates; thus, definitive surgical techniques must be preferred. [ABSTRACT FROM AUTHOR]

The incidence of intestinal tuberculosis (ITB) has been increasing in the West, due to the AIDS epidemic, transglobal immigration, IV drug abuse, an aging population, and an increase in the number of immunocompromised patients. Obstruction and perforation of the intestine are the most common and serious complications of ITB. Another complication, tuberculous liver abscess (TLA), is rare and usually associated with foci of infection in the lung or gastrointestinal tract. We report a case of a 17-year-old boy with Down syndrome who presented with multiple TLAs secondary to obstructive and multiple perforated ileal tuberculosis. [ABSTRACT FROM AUTHOR]

PURPOSE:. This study was designed to review the outcomes of 63 patients with ileosigmoidal knotting. METHODS:. Sixty-three, surgically treated patients (47 males; 74.6 percent) were reviewed retrospectively. The mean age was 45.6 (range, 7–75) years. The most common symptoms were abdominal pain and obstipation, and the most common signs were abdominal tenderness and distention. The preoperative diagnosis was obstructive emergencies in 49 patients (77.8 percent) and nonobstructive emergencies in 14 (22.2 percent). RESULTS:. All patients underwent emergency laparotomy. The most common type of ileosigmoidal knotting was Type 1A in 30 patients (47.6 percent), in which the active ileum encircled the passive sigmoid colon in a clockwise direction. Fifty patients (79.4 percent) developed gangrenous bowel. Resection of gangrenous segments and enteroenteric or enterocolic anastomosis combined with the Hartmann procedure was the most preferred operation, used in 34 patients (54 percent). The mortality rate was 15.9 percent (10 patients), and toxic shock was the most frequent cause of death. CONCLUSIONS:. Ileosigmoidal knotting is a rare but serious form of intestinal obstruction. Its preoperative diagnosis is difficult and may present as an obstructive or nonobstructive emergency. Early and effective resuscitation, prompt surgical intervention selected on the basis of clinical and operative findings, and effective postoperative intensive care are the basis of treatment. [ABSTRACT FROM AUTHOR]

New ligands of Schiff bases [(C17H12NOX), X = F, Cl, Br, I] have been synthesised. Intra-molecular hydrogen bonding and keto-enamine tautomerism have been studied using IR, 1H-NMR, 13C-NMR (DEPT), UV-Visible and GC-MS techniques. The UV-Visible spectra of the compounds have been investigated in different solvents, acidic and basic media. The compounds were in tautomeric equilibrium (enol-imine O–H[ctdot]N, keto-amine O[ctdot]H–N forms) in polar and nonpolar solvents. The keto-amine form was observed in basic solutions of DMSO, ethanol, chloroform, benzene, and cyclohexane, and in acidic solutions of chloroform and benzene, but not in acidic solutions of DMSO and ethanol. 1H-NMR and 13C-NMR and IR results showed that all Schiff bases studied favor the enol-imine form over the keto form in a weakly polar solvent such as deuterochloroform solution. [ABSTRACT FROM AUTHOR]

This paper describes an investigation of the reduction of nitrobenzene to p-aminophenol by the use of CV, RDE and preparative electrolysis with Cu and Cu(Hg) electrodes. The preparative electrolyses of nitrobenzene were carried out at controlled current and controlled potential conditions using copper and amalgamated copper using a new semipilot (laboratory) scale system in the absence of an organic cosolvent. The effects of redox reagents and the concentration of nitrobenzene in catholyte added to the medium were also examined. The best results were obtained with 2.3% BiCl3 at nitrobenzene concentration of 0.144 g cm−3 catholyte. The most suitable electrode material was found to be amalgamated copper and the reduction of nitrobenzene to p-aminophenol was found to follow an ECE mechanism. [ABSTRACT FROM AUTHOR]

This study is concerned with the cathodic reduction of 4-nitroso- N, N-dimethylaniline to 4-amino- N, N-dimethylaniline in 1.0 M HCl and 1.0 M H2SO4 containing 10% MeOH. The effect of cathode material, supporting electrolyte, electroactive compound concentration, temperature and current density in the electrochemical synthesis of 4-amino- N, N-dimethylaniline were investigated. The best cathode material was tin, which gave a selectivity of 92.7% with a current yield of 90.3% at a current density of 6 mA cm−2. The final electrolysis product was obtained as its respective HCl and H2SO4 salts and their structures were elucidated using spectrochemical techniques. [ABSTRACT FROM AUTHOR]

Hypothesis: To review the results of different modalities of treatment of hydatid disease of the liver. Design: Retrospective study of 304 patients. Setting: A university hospital in Turkey. Patients: Three hundred four patients with hepatic hydatid disease who underwent operation between 1981 and 1996. Main Outcome Measures: Mortality and morbidity. Results: Two hundred thirty-eight patients had a cyst on the right lobe, 41 patients had a cyst on the left lobe, and 25 patients had a cyst on both lobes. Forty-five patients had multiple hepatic cysts and 18 patients had coexisting cysts in other intra-abdominal organs. Surgical procedures were tube drainage, capitonnage, omentoplasty, cystectomy, segmentectomy, and cystoenterostomy. Of the patients with tube drainage, 36 developed an infection of the remaining cavity, 10 developed long-lasting biliary fistula, 8 developed cholangitis, and 6 developed septicemia. Four patients died of unreleated complications. Of the patients with capitonnage, 7 developed cholangitis and 3 developed an infection of the remaining cavity. Of the patients with omentoplasty, 1 developed an infection of the remaining cavity and 1 developed cholangitis. One patient who underwent segmentectomy developed pulmonary complications. Of the patients with cystoenterostomy, 1 developed cholangitis, 1 developed septicemia, and 1 developed pulmonary complications. Conclusion: For management of hydatid disease of the liver, capitonnage, omentoplasty, cyst excision, segmentectomy, or cystoenterostomy are all superior to tube drainage. [ABSTRACT FROM AUTHOR]

Cerebellar abscess is a serious complication of ear disease. In the present report, a case of cerebellar abscess and thrombosis of the sigmoid sinus, secondary to chronic otitis media is described. A 25-year-old male presented with clinical features suggestive of chronic suppurative otitis media. The patient hospitalized for operation. In postoperative third day the patient began to complain about headache. The patient suddenly began to lose his balance while walking and had difficulty in talking. MRI revealed that there was a cerebellar abscess and operated him for the cerebellar abscess. After 6 weeks antibiotherapy the patient discharged from the hospital as cured. As seen in the literature review; most of the patients having thrombosis of the sigmoid sinus and cerebellar abscess together have showed the symptoms of cerebellar abscess. However, the symptoms of thrombosis of the sigmoid sinus were more prominent than cerebellar abscess in our case unlike many others in the literature. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article pertaining to the extraskeletal Ewing's sarcoma in the abdominal wall published in a previous issue of this periodical.