Optimization of the annealed proton exchange method with controlled annealing for multifunctional integrated optical chip production.

The main objective of our study is to develop a new approach to the annealed proton exchange (APE) method for the fabrication of the multifunctional integrated optical chip (MIOC) used in fiber-optic gyro systems and to eliminate the loss of time and material, especially in mass production applications. In this work, self-polarized waveguides, which are the basic components of a MIOC device, were produced by the APE method and studied. With the developed method, controlled annealing trials have been carried out from a certain region on the LiNbO3 substrate used in waveguide production, and the annealing time specific to the annealing process was determined. By utilizing a special setup for the hot acid process, the proton exchange process was accomplished without a sudden temperature change of the substrate. Using prism coupling measurements of the fabricated waveguides, annealing times were determined to obtain index change values suitable for 45%-50% optical throughput. Mode profiles of devices with high optical throughput that were produced by the proposed method were measured, and it was seen that devices from different proton exchange runs had similar profiles. As a result, many undamaged substrates were fabricated, and their optical quality was found to be within the expected values.

Fiber-optic gyroscope for the suppression of a Faraday-effect-induced bias error.

Inertial rotation sensors, interferometric fiber-optic gyroscopes (IFOGs), are widely used in military and industrial applications due to their high sensitivity and stability. In this Letter, a new, to the best of our knowledge, fiber coil design is proposed to reduce magnetic field sensitivity without adding any optical components or electronic algorithms to the IFOG system. It is shown that this design can be applied without disturbing the simplest IFOG structure. Considering the fact that the magnetic field has an invertible effect on polarization, the compensation of the Faraday-effect-induced bias error has been demonstrated theoretically and experimentally by allowing two different polarizations to travel inside the fiber coil. According to the experimental results, the bias error was reduced approximately 20 times from ±9.6∘/h/mT to ±0.5∘/h/mT.

Synthesis and Spectroscopic Studies of Novel Rhodanine Azo Dyes: An Excellent Selective Chemosensor for Naked-eye Detecting of Cu2+ Ion.

This study is first report on the synthesis of novel rhodanine based azo dyes and their fluorogenic and chromogenic sensing behaviors with metal ions (Li+, Na+, K+, Rb+, Pb2+, Ni2+, Zn2+, Cu2+) by using UV-vis and fluorescence spectroscopy techniques. The results of spectroscopic experiments for rhodanine based azo dye 1a exhibited excellent selectivity for Cu2+ over the other metal ions. Furthermore, anti-bacterial studies of rhodanine azo dyes were performed towards some selected bacteria via microbroth dilution method. Obtained results showed that rhodanine ionophore 1a showed strong antibacterial activity against S.aureus.

Phototoxic dermatitis due to Chenopodium album in a child.

In this article, we report a 2-year-old girl with severe phototoxic dermatitis caused by ingestion of Chenopodium album. To the best of our knowledge, this is the first case of phototoxic dermatitis due to Chenopodium album in childhood.

[Sepsis caused by Chryseobacterium indologenes in a patient with hydrocephalus]. / Hidrosefalisi Olan Bir Olguda Chryseobacterium indologenes ile Iliskili Sepsis.

Chryseobacterium (formerly Flavobacterium) indologenes, is a non-fermentative gram-negative bacillus which is widely found in the nature, primarily soil and water. Since it can survive in chlorine-treated municipal water supplies, and can colonize the sink basins and tap waters of the hospitals, this bacterium may be a potential infectious agent. Contamination of the medical devices containing water (respirators, intubation tubes, humidifiers, incubators for newborns, etc.) in hospital settings may lead to serious infections especially in patients with predisposing diseases, newborns and immunocompromized patients. In this report, a case of fatal C.indologenes septicemia developed in a newborn with hydrocephalus has been presented. A two-months old male infant was admitted to our hospital with the complaints of failure to suck and lethargy for five days and head enlargement. He was diagnosed as meningitis based on the clinical and laboratory findings of cerebrospinal fluid (CSF) (protein: 572 mg/dl, glucose 9.5 mg/dl, chlorine: 111 mg/dl, and presence of abundant polymorphonuclear leukocytes), and empirical antibiotic treatment (ampicillin/sulbactam and cefotaxime) had been started. Since the computerized tomography of the brain pointed out hydrocephalus, an external shunt was placed for CSF drainage on the second day of hospitalization. A total of five CSF and two blood cultures collected during the hospitalization period were inoculated into pediatric aerobic CSF and blood culture bottles (BacT/ALERT, BioMerieux, France) and incubated for 24-48 hours. The isolated bacteria from all of the cultures were identified as C.indologenes by conventional methods and BD Phoenix (Becton Dickinson, USA) system. Antibiotic susceptibility tests were performed with microdilution method according to CLSI guidelines. The isolate was found susceptible to ciprofloxacin, levofloxacin and trimethoprim/sulfamethoxazole, while it was resistant to amikacin, gentamicin, tobramycin, piperacillin, cefotaxime, ceftazidime, aztreonam, meropenem, imipenem, tetracycline, and chloramphenicol. The treatment continued with ampicillin/sulbactam and levofloxacin without removing the shunt. However, C.indologenes growth persisted in CSF and blood cultures of the patient. The general condition of the patient deteriorated on the 65. day of the hospitalization and the patient was lost due to cardiopulmonary arrest. Case reports related to isolation of C.indologenes from blood cultures are present in the literature, however, isolation of C.indologenes from central nervous system was reported previously in a single case. In conclusion, C.indologenes should be considered as opportunistic infectious agents especially in the infectious diseases that develop in immunocompromised patients with underlying disease and with foreign device implementation.

Severe hypernatremia in newborns due to salting.

The aim of this study was to evaluate the etiology, clinical, and laboratory findings and prognostic features of life-threatening hypernatremic newborns secondary to salting. Ten severely hypernatremic newborns (four females) with a mean age of 6.5 +/- 2.6 days were followed up. Nine of them were full term, and one was preterm. It was noticeable that 60% of them were small for gestational age. In the laboratory investigation, five uremias were detected. It was interesting to find in the etiologic history that 40% of the patients had been salted just after birth. Twenty percent of them had also hyperbilirubinemia and kernicterus, 20% had neonatal convulsion, and 50% had dehydration. Two of the hypernatremic newborns died during the study; the others were followed up. One case had spasticity and developmental disability at the 3rd month, and another one had developmental disability at the 6th month of ages. As a conclusion, although salting of newborns is not so frequent, it could be seen in rural places of our country, and this may be one of the reasons for serious hypernatremia in newborns whose skin integrity have not been formed completely. These cases should be treated carefully.

Brachial plexus paralysis due to giant cavernous hemangioma with Kasabach-Merritt syndrome: successful management with interferon alpha.

Giant hemangiomas are rare in newborn babies and may cause some life-threatening complications such as congestive heart failure and coagulopathies including severe thrombocytopenia, microangiopathic hemolytic anemia and bleeding such as Kasabach-Merritt syndrome. We have presented here one infant case with a right lower brachial plexus paralysis due to giant hemangioma treated successfully with interferon alpha and have discussed the treatment. This is the first case of Kasabach-Merritt syndrome associated with a right lower brachial plexus paralysis treated with interferon in the literature to our knowledge. The administration of interferon-alpha might be indicated as a therapy for severe, life-threatening and giant hemangiomas such as Kasabach-Merritt syndrome, especially when there is resistance to steroid. However, more extensive data and new patients are needed to clarify this issue.

[First isolation and detection of multiple clones of vancomycin-resistant enterococci in the pediatric unit of Van Yuzuncu Yil University Turkey]. / Van Yüzüncü Yil Universitesi Pediatri Servisinde vankomisine dirençli enterokoklarin ilk izolasyonu ve çogul klonlarin tespiti.

Upon isolation of the first vancomycin resistant enterococcus (VRE) from the urine sample of a nine months old patient in pediatric unit of Van Yuzuncu Yil University Hospital (located in eastern part of Turkey), we aimed to search for the presence of VRE isolates in the unit, to determine the resistance genotypes and to evaluate the clonal relationships among isolates. A total of 28 rectal swabs and 28 skin swabs from the patients, 12 skin swabs from the staff giving care to the patients, 15 skin swabs from the mothers of the patients and 96 environmental samples from the pediatric unit were screened. Antibiotic susceptibilities were tested and the resistance genotypes were determined. Molecular typing of the isolates was performed using pulsed-field gel electrophoresis (PFGE). Apart from the first case, 13 more VRE isolates, one being a clinical isolate from the urine of a patient and 12 isolates from the screening samples (8 rectal swabs, one skin swab and three swabs from patients' beds) were obtained. All of the isolates were identified as Enterococcus faecium with similar antibiotic susceptibility patterns. VanA gene was present in all of the isolates. PFGE demonstrated two major clones and five clones closely related with the major ones. This was the first VRE isolation and colonization reported in our region. The isolates belonged to more than one clone. Currently, VRE did not seem to be a significant pathogen in Turkey, however, there may be an underestimation of the problem and continuous surveillance studies should be undertaken in every region.

Prevalence of Helicobacter pylori in children and their family members in a district in Turkey.

The aim of this study was to determine the prevalence of Helicobacter pylori among children and their family members and to evaluate some epidemiologic characteristics. The study included 275 children, aged 1-15 year(s), suffering from different gastrointestinal complaints. Blood serology and stool antigen testing were used for the diagnosis of infection due to H. pylori. Sixty-five (23.6%) of the 275 children were positive for H. pylori, and this positivity had a significantly increasing correlation with age (p<0.001). H. pylori-associated infection was observed among 45 (69.2%) and 17 (8%) mothers in the H. pylori-infected and non-infected groups respectively (p<0.0001). Most children and their families infected with H. pylori were living in an urban area. The findings suggest that infection due to H. pylori is a problem for this district area, and all children having any gastrointestinal complaints should be examined whether H. pylori was prevalent among their family members.

Relaxation dynamics and polydispersivity associated with defects and ferroelectric correlations in Ba-doped EuTiO3.

We present the frequency- and temperature-dependent dielectric response of Eu1-x Ba x TiO3 (0 ⩽ x ⩽ 0.5) in detail. Excluding grain boundary effects, four relaxation mechanisms were observed. Relaxation dynamics were observed to arise due to hopping conduction associated with defects, namely oxygen vacancies as well as Eu3+ and Ti3+ ions. Dielectric relaxation analysis led to the identification of Ti ions in two different environments with different relaxation rates in the overall EuTiO3 perovskite structure. The emergence of another relaxation mechanism associated with ferroelectric order as a consequence of the formation of polar regions was also observed for higher Ba concentrations. The addition of Ba led to the identification of relaxation dynamics associated with hopping conduction between Eu ions, Ti ions (in the regions with and without oxygen vacancies) and with the formation of ferroelectric polar regions. Furthermore, the polydispersivity and relaxation times were extracted within the framework of the modified Debye model. Relaxation times have been observed to increase with a decrease in temperature while larger values of polydispersivity reveal a wide distribution of relaxation times due to the presence of lattice parameter and energy barrier distributions.

Reactive gas condensation synthesis of aluminum nitride nanoparticles.

Aluminum Nitride (AIN) nanoparticles were synthesized using a Reactive Gas Condensation (RGC) technique in which a mixture of ammonia (NH3) and nitrogen (N2) gases were used for the nitridation of aluminum. NH3 served as the reactive gas, while N2 served as both a carrier gas and the inert source for particle condensation. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses revealed that at reactive gas compositions greater than 10% NH3 in N2, samples were composed entirely of hexagonal AIN nanoparticles. Electron diffraction patterns showed single crystal hexagonal AIN structure. The particle size was controlled by varying the pressure of the gas mixture. AIN nanoparticles were dispersed in a liquid matrix to enhance thermal conductivity. Results showed that a minimal addition of AIN increased the thermal conductivity of hydrocarbon pump oil by approximately 27%. The thermal conductivity became constant after reaching a maximum above 0.01 wt% AIN. Temporal stability of AIN was studied by XRD. Samples exposed to air for extended periods of time and analyzed by XRD show no degradation of crystalline AIN nanoparticles.

Seroprevalence of hepatitis a and associated factors among 1-15 year old children in Eastern Turkey.

BACKGROUND: Hepatitis A is a common infectious disease during childhood worldwide. Recently, great deal of changes in the epidemiology has been reported. The seroepidemiologic studies of this infection are not sufficient in Eastern region of Turkey. OBJECTIVE: To investigate the seroprevalence and association with socio-demographic variables of hepatitis A in 1-15 year old children in Van. PATIENTS AND METHODS: This study was performed on 510 one to fifteen year old children from outpatient pediatric clinics in Yüzüncü Yil University, Faculty of Medicine during last three months of 2009. Anti-HAV IgG was measured in sera by enzyme-linked immunosorbent assay. The information about subjects was recorded on standardized forms and a chart review survey was performed. RESULTS: The overall ratio for seropositivity was 54.9%. Statistical significance was found between hepatitis A seroprevalence and age, collective use of domestic items, fresh water resources, localization and type of toilet and the number of households. CONCLUSION: This study provided the most recent data of seropositivity and revealed the preliminary indication of epidemiological shift in seroprevalence of Hepatitis A virus in a region with high endemicity.

[Tibial osteomyelitis following intraosseous infusion: a case report]. / Kemik içi infüzyonuna bagli tibia osteomiyeliti: Olgu sunumu.

Fluids, medications, and blood products can be rapidly administered via intraosseous infusion under emergency conditions, particularly to pediatric patients aged from 0 to 2 years. A five-month-old infant who had been hospitalized with a diagnosis of sepsis developed swelling and hyperemia at the infusion site 10 days after an intraosseous infusion in the right proximal tibia. Physical examination showed a serous discharge from a fistula on the anteromedial side of the right proximal cruris. Plain radiographs demonstrated periosteal reaction in the right tibia and osteolytic areas in the proximal metaphysis. With a diagnosis of acute osteomyelitis, drainage and medullary irrigation were performed and parenteral antibiotic treatment was initiated. Cultures from the surgical site yielded Candida albicans, upon which fluconazole (8 mg/kg) treatment was administered for four weeks. A complete clinical and radiographic improvement was observed at the end of a 12-month follow-up.

The importance of administration of early surfactant and nasal continuous positive airway pressure in newborns with respiratory distress syndrome.

AIM: Mechanical ventilation is an invasive method and causes to important problems in the respiratory tract and lung parenchyma. The objective of our study was to investigate if administration of early surfactant and nasal continuous positive airway pressure (nCPAP) was superior to delayed surfactant administration and mechanical ventilation. MATERIAL AND METHODS: The study was conducted in the Van 100th Year University, Medical Faculty Hospital, Neonatal Intensive Care Unit. One hundred and nine infants with respiratory distrss syndrome (RDS) with a gestational age of 32 weeks and/or below were included in the study. Surfactant was given to 61 infants in the delivery room or intensive care unit and subsequently nCPAP was administered. Surfactant was administered in 48 infants in the control group and mechanical ventilation was inititated subsequently. Informed consent was obtained from the relatives of all patients and ethics committee approval was also obtained (Approval number: 03.02.2011/15). RESULTS: There was no statistically significant difference between the two groups in terms of gestational age, birth weight, gender, height and head circumference measurements (p>0.05). The mean hospitalization time in the patients in the study group was 24.4±17.8 days, whereas the mean time of nCPAP was 28.4 (4-120) hours. In the study group, intracranial hemorrhage was found with a rate of 27.85%, bronchopulmonary dysplasia was found with a rate of 4.91%, pneumothorax was found with a rate of 3.27%, necrotizing enterocolitis was found with a rate of 3.27%, patent ductus arteriosus was found with a rate of 16.39, sepsis was found with a rate of 22.95% and retinopathy of prematurity was found with a rate of 1.63%. No statistically significant difference was found between the study and control groups in terms of the rates of complications. During the follow-up period, 17 (27.86%) patients were lost. The length of stay on mechanical ventilation in the study group was found to be statistically significantly shorter compared to the control group (p<0.05). CONCLUSIONS: In our study, it was observed that administration of early surfactant and nCPAP in treatment of preterm newborns with a diagnosis of RDS markedly decreased the lenght of stay on mechanical ventilation, but had no significant impact on morbidity and mortality.

Neonatal brucellosis and breast milk.

In this case report the authors present an extremely low birth weight premature infant with neonatal brucellosis whose mother had been treated for brucellosis during pregnancy. Infant developed mild respiratory distress syndrome soon after birth. At 2nd wk of postnatal age findings of bronchopulmonary dysplasia were evident and she and her mother were diagnosed to have brucellosis at the same time. After commencement of antibrucellosis therapy and nonspesific treatment for bronchopulmonary dysplasia, infant was completely cured of the symptoms related to both brucellosis and bronchopulmonary dysplasia. The results of the present case and a review of the literature have let to conclude that Brucella might have role in development of prematurity and bronchoplumonary dysplasia. Since discovery of brucella bacilli in early periods of 20th century, fetotoxicity of brucella bacilli seems to increase gradually suggesting an increasing virulance of the bacilli or vanishing host defense of human beings.

DNA-positive, IgM-negative symptomatic congenital cytomegalovirus infection: two case reports.

The characteristics of two newborns that had clinical symptoms of congenital cytomegalovirus have been presented here, whose CMV-DNA was found to be positive by the PCR method, despite serological analysis being negative for CMV IgM. In conclusion, when congenital CMV infection is suspected in newborns, it should not be forgotten that the sensitivity of serological CMV IgM assay is 70% and other methods such as CMV-DNA analysis should be performed in case of negative test results.

Necrotizing fasciitis caused by Staphylococcus epidermidis in a neonate with extremely low birthweight.

Necrotizing fasciitis (NF) is a severe life-threatening soft tissue infection characterized by rapidly spreading necrosis of the fascia and the subcutaneous tissue. The initial skin presentation ranges from minimal rash to cellulites. The lesions subsequently spread rapidly. Even with appropriate medical and surgical therapy, the mortality rate in NF is more than 50%. In cases of neonates, mortality rate is higher than that ratio. High index of suspicion, prompt aggressive surgery, appropriate antibiotics and supportive care are the mainstays of management in the newborn infant with NF. Herein, we report a case of invasive and mortal NF caused by Staphylococcus epidermidis in an infant with extremely low birthweight.