272 research outputs found

    Application of response surface methodology in process parameters optimization for phenol mineralization using Fenton’s peroxidation

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    Adverse effect of the highly biorecalcitrant compound phenol to the environment is well established and its concentrations in industrial effluents vary greatly from 2.8 to 6,800 mg/l depending on the source. Fenton process effectively mineralises to CO2 and H2O but reported works consumed more reagents and require longer reaction times. Due to the strong interaction between the several predictor variables in the Fenton oxidation, response surface methodology was used to optimise the mineralization treatment. Efficient, faster and economical operating conditions for phenol removal were explored by investigating four parameters namely the concentration ratio of hydrogen peroxide to phenol - ((H2O2):(Phenol)), mass ratio of hydrogen peroxide to ferrous ions - ((H2O2):(Fe2+)), initial phenol concentration - ([Phenol]o) and reaction time - (tr). The optimal TOC % reduction obtained were 35 and 88% for initial phenol concentrations of 100 and 5 mg/l, respectively. Reaction conditions corresponding to this phenol mineralization a reaction time of 20 min at ratios of 6 and 15 for [H2O2]:[Phenol] and [H2O2]:[Fe2+], respectively. For mineralisation at 52.5 mg/l phenol concentration, the optimal conditions were 20 min, ratios 10 and 15 for the reaction time, [H2O2]:[Phenol] and [H2O2]:[Fe2+], respectively. The soluble iron content of the analysed supernatant was found to be below the 15 mg/l (the maximum limit allowable for total iron discharges required by common regulative subscribed). This indicated that, the Fenton reagents were utilised during the peroxidation reaction evident from the almost near consumption of all Fe2+ introduced in about 85% of the samples, thus, negating the need for immobilising the Fe2+ catalyst or its removal by post treatment. The work proves that the optimized Fenton process can be potentially used for treatment of any phenol containing wastewater.Key words: Fenton process, phenol mineralization, response surface methodology

    Prolonged venous bleeding due to traditional treatment with leech bite: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>The medicinal leech, <it>Hirudo medicinalis</it>, has been used in the treatment of many diseases for thousands of years. In Turkey, it is used most commonly in the management of venous diseases of lower extremities.</p> <p>Case presentation</p> <p>A 25-year-old Turkish woman presented to our emergency room with bleeding from her left leg. She had been treated for varicose veins in her lower extremities with leeches about 24 hours before admission to the emergency room. The bleeding was controlled by applying pressure with sterile gauze upon the wound, and she was discharged. She returned after four hours having started bleeding again. Hemostasis was achieved by vein ligation under local anesthesia.</p> <p>Conclusions</p> <p>Leech bite should be evaluated as a special injury. Prolonged bleeding can be seen after leech bites. In such cases, hemostasis either with local pressure or ligation of the bleeding vessel is mandatory.</p

    Strain-induced partially flat band, helical snake states, and interface superconductivity in topological crystalline insulators

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    Topological crystalline insulators in IV-VI compounds host novel topological surface states consisting of multi-valley massless Dirac fermions at low energy. Here we show that strain generically acts as an effective gauge field on these Dirac fermions and creates pseudo-Landau orbitals without breaking time-reversal symmetry. We predict the realization of this phenomenon in IV-VI semiconductor heterostructures, due to a naturally occurring misfit dislocation array at the interface that produces a periodically varying strain field. Remarkably, the zero-energy Landau orbitals form a flat band in the vicinity of the Dirac point, and coexist with a network of snake states at higher energy. We propose that the high density of states of this flat band gives rise to interface superconductivity observed in IV-VI semiconductor multilayers at unusually high temperatures, with non-BCS behavior. Our work demonstrates a new route to altering macroscopic electronic properties to achieve a partially flat band, and paves the way for realizing novel correlated states of matter.Comment: Accepted by Nature Physic

    Primary subcutaneous cyst hydatic disease in proximal thigh: an unusual localisation: a case report

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    BACKGROUND: Musculoskeletal hydatidosis is very rare and represents 1% – 5.4% of all cases of echinococcosis. On clinical basis, infection mimics a soft-tissue tumor, and the preoperative radiological diagnosis is very important to avoid biopsy. CASE PRESENTATION: We report an unusual case of primary subcutaneous hydatidosis in proximity to vastus lateralis muscle. It was diagnosed according to the computed tomography appearance, clinical and pathological findings. A 43 year old female patient was admitted with a history of pain at proximal thigh for the last 30 days. On physical examination, a mass which was 4 × 5 cm in diameter, painful and erythamatous, was palpated over greater trochanter. Sedimentation rate was 40 mm in the first hour. CT (Computed Tomography) scan demonstrated, a soft tissue mass with central cystic component in the subcutaneous tissue near vastus lateralis muscle. Histopathological examination of the specimen revealed a pericystic structure, which consisted of connective tissue and scattered hyaline cells showing a necrotic basophilic structure that resembled a cuticular membrane. Treatment with high dose albendazole was conducted for 4 weeks. CONCLUSIONS: This case illustrates that echinococcal disease should be considered in the differential diagnosis of every cystic mass in every anatomic location, especially when they occur in areas where the disease is endemic

    Religious Officials' knowledge, attitude, and behavior towards smoking and the new tobacco law in Kahramanmaras, Turkey

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    <p>Abstract</p> <p>Background</p> <p>Tobacco control effort should be first started in people that are looked upon as role models for the general population. We aimed to determine the knowledge, attitude, and behavior of religious officials towards smoking and the new tobacco law.</p> <p>Method</p> <p>The study group was comprised of 492 Imams and 149 Quran course instructors working in Kahramanmaras city of Turkey, 641 religious officials in total, and our survey form was applied on 406 (63.3%) of those religious officials who agreed to participate in the study.</p> <p>Results</p> <p>Twenty-eight (6.9%) participants were current smokers and 35 (8.6%) were ex-smokers. 99.8% of the religious officials believed that smoking was harmful and/or prohibited in terms of religion. While 43.6% respondents thought smoking was "<it>haram</it>" (forbidden by Islam), 56.2% believed it was "<it>makruh</it>" (something regarded as reprehensible, though not forbidden by God according to Islam). 85.2% of the participants were aware of the recent tobacco law. 55.5% of the respondents, who were aware of the recent tobacco law, evaluated their knowledge level on the law as adequate, whereas 44.5% evaluated it as inadequate 92.4% of the participants noted that religious officials should play active roles in tobacco control effort.</p> <p>Conclusion</p> <p>Smoking rate among religious officials is much lower than that of general public. In order to help religious officials to take a more active role on this issue, they should be trained on the subject and appropriate platforms should be established.</p

    Biodegradation kinetics of 4-fluorocinnamic acid by a consortium of Arthrobacter and Ralstonia strains

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    Arthrobacter sp. strain G1 is able to grow on 4-fluorocinnamic acid (4-FCA) as sole carbon source. The organism converts 4-FCA into 4-fluorobenzoic acid (4-FBA) and utilizes the two-carbon side-chain for growth with some formation of 4-fluoroacetophenone as a dead-end side product. We also have isolated Ralstonia sp. strain H1, an organism that degrades 4-FBA. A consortium of strains G1 and H1 degraded 4-FCA with Monod kinetics during growth in batch and continuous cultures. Specific growth rates of strain G1 and specific degradation rates of 4-FCA were observed to follow substrate inhibition kinetics, which could be modeled using the kinetic models of Haldane–Andrew and Luong–Levenspiel. The mixed culture showed complete mineralization of 4-FCA with quantitative release of fluoride, both in batch and continuous cultures. Steady-state chemostat cultures that were exposed to shock loadings of substrate responded with rapid degradation and returned to steady-state in 10–15 h, indicating that the mixed culture provided a robust system for continuous 4-FCA degradation

    Altered Neurocircuitry in the Dopamine Transporter Knockout Mouse Brain

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    The plasma membrane transporters for the monoamine neurotransmitters dopamine, serotonin, and norepinephrine modulate the dynamics of these monoamine neurotransmitters. Thus, activity of these transporters has significant consequences for monoamine activity throughout the brain and for a number of neurological and psychiatric disorders. Gene knockout (KO) mice that reduce or eliminate expression of each of these monoamine transporters have provided a wealth of new information about the function of these proteins at molecular, physiological and behavioral levels. In the present work we use the unique properties of magnetic resonance imaging (MRI) to probe the effects of altered dopaminergic dynamics on meso-scale neuronal circuitry and overall brain morphology, since changes at these levels of organization might help to account for some of the extensive pharmacological and behavioral differences observed in dopamine transporter (DAT) KO mice. Despite the smaller size of these animals, voxel-wise statistical comparison of high resolution structural MR images indicated little morphological change as a consequence of DAT KO. Likewise, proton magnetic resonance spectra recorded in the striatum indicated no significant changes in detectable metabolite concentrations between DAT KO and wild-type (WT) mice. In contrast, alterations in the circuitry from the prefrontal cortex to the mesocortical limbic system, an important brain component intimately tied to function of mesolimbic/mesocortical dopamine reward pathways, were revealed by manganese-enhanced MRI (MEMRI). Analysis of co-registered MEMRI images taken over the 26 hours after introduction of Mn^(2+) into the prefrontal cortex indicated that DAT KO mice have a truncated Mn^(2+) distribution within this circuitry with little accumulation beyond the thalamus or contralateral to the injection site. By contrast, WT littermates exhibit Mn^(2+) transport into more posterior midbrain nuclei and contralateral mesolimbic structures at 26 hr post-injection. Thus, DAT KO mice appear, at this level of anatomic resolution, to have preserved cortico-striatal-thalamic connectivity but diminished robustness of reward-modulating circuitry distal to the thalamus. This is in contradistinction to the state of this circuitry in serotonin transporter KO mice where we observed more robust connectivity in more posterior brain regions using methods identical to those employed here

    Exercise-induced laryngeal obstruction: natural history and effect of surgical treatment

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    The current follow-up study concerning the supraglottic type of exercise-induced laryngeal obstruction (EILO) was performed to reveal the natural history of supraglottic EILO and compare the symptoms, as well as the laryngeal function in conservatively versus surgically treated patients. A questionnaire-based survey was conducted 2–5 years after EILO was diagnosed by a continuous laryngoscopy exercise (CLE) test in 94 patients with a predominantly supraglottic obstruction. Seventy-one patients had been treated conservatively and 23 with laser supraglottoplasty. The questionnaire response rate was 70 and 100% in conservatively treated (CT) and surgically treated (ST) patients, respectively. A second CLE test was performed in 14 CT and 19 ST patients. A visual analogue scale on symptom severity indicated improvements in both the groups, i.e. mean values (± standard deviations) declined from 73 (20) to 53 (26) (P < 0.001) in the CT group and from 87 (26) to 25 (27) (P < 0.001) in the ST group. At follow-up, ST patients reported lower scores regarding current level of complaints, and higher ability to perform exercise, as well as to push themselves physically, all compared to CT patients (P < 0.001). CLE scores were normalized in 3 of 14 (21%) CT and 16 of 19 (84%) ST patients (Z = −3.6; P < 0.001). In conclusion, symptoms of EILO diagnosed in adolescents generally decreased during 2–5 years follow-up period but even more after the surgical treatment. Patients with supraglottic EILO may benefit from supraglottoplasty both as to laryngeal function and symptom relief

    Hepatitis B Virus Impairs TLR9 Expression and Function in Plasmacytoid Dendritic Cells

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    Plasmacytoid dendritic cells (pDCs) play a key role in detecting pathogens by producing large amounts of type I interferon (IFN) by sensing the presence of viral infections through the Toll-Like Receptor (TLR) pathway. TLR9 is a sensor of viral and bacterial DNA motifs and activates the IRF7 transcription factor which leads to type I IFN secretion by pDCs. However, during chronic hepatitis B virus (HBV) infection, pDCs display an impaired ability to secrete IFN-α following ex vivo stimulation with TLR9 ligands. Here we highlight several strategies used by HBV to block IFN-α production through a specific impairment of the TLR9 signaling. Our results show that HBV particle internalisation could inhibit TLR9- but not TLR7-mediated secretion of IFN-α by pDCs. We observed that HBV down-regulated TLR9 transcriptional activity in pDCs and B cells in which TLR9 mRNA and protein levels were reduced. HBV can interfere with TLR9 activity by blocking the MyD88-IRAK4 axis and Sendai virus targeting IRF7 to block IFN-α production. Neutralising CpG motif sequences were identified within HBV DNA genome of genotypes A to H which displayed a suppressive effect on TLR9-immune activation. Moreover, TLR9 mRNA and protein were downregulated in PBMCs from patients with HBV-associated chronic hepatitis and hepatocellular carcinoma. Thus HBV has developed several escape mechanisms to avoid TLR9 activation in both pDCs and B lymphocytes, which may in turn contribute to the establishment and/or persistence of chronic infection
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