Thin film preparation of polyphenol oxidase enzyme (PPO) and investigation of its organic vapor interaction mechanism.

This study investigated spin coated thin films of polyphenol oxidase (PPO) enzyme as vapor sensor to detect chloroform, acetone, ethyl acetate, isopropyl alcohol and toluene. Thin film of enzyme was produced onto a bio-composite (gelatine chitosan) first layer via 5000 rpm spin speed. The density and the viscosity of the enzyme were 1.2 g ml-1and 68 mPa.s respectively. UV-visible spectroscopy and quartz crystal microbalance (QCM) measurements were carried out to analyze the reproducibility of PPO spun film. It was found that the PPO enzyme can be transferred onto a solid substrate as a solid state thin film form. The sensor films of PPO enzyme were exposed to various volatile organic compounds (VOCs) (chloroform, acetone, ethyl acetate, isopropyl alcohol and toluene) with different fixed concentrations. The sensing responses of PPO thin films versus five vapors were investigated using QCM as the time dependence frequency recording method. The PPO sensor films exhibited high sensitivity and fast responses against all VOCs. But the response rate and magnitude were changed depending on the chemical structure and the molecular size of the analyte vapor. Recorded frequency changes as monitored by QCM technique have been integrated with the Fick's second law of diffusion to determine the diffusion coefficients of analyte vapors. The results showed that the interaction characteristics between PPO and the analytes can be considered in terms of two main processes which are surface interaction and diffusion. And it was concluded that the formation of these two processes during the interaction depend on the molecular size and functional group of the analytes. These results showed that enzymes can be integrated into vapor sensor system as active layer and are promising for further sensor studies.

The impact of the Adenotonsillectomy on cardiac functions and oxidative stress.

OBJECTIVE: Obstructive sleep apnea syndrome (OSAS) causes cardiovascular comorbidities and increased oxidative stress. Adenotonsillectomy is the first treatment option for OSAS secondary to adenotonsillar hypertrophy (ATH). This study evaluated the presence of cardiovascular changes, hypertension and oxidative stress before and after adenotonsillectomy in patients with OSAS secondary to ATH. METHODS: Patients with ATH diagnosed with OSAS by polysomnography (PSG) were included. All participants received an Echocardiography (ECHO) and 24-h ambulatory blood pressure measurement (ABPM). Serum malonyldialdehyde (MDA) and total oxidant activity (TOS) levels of oxidant parameters; total antioxidant activity (TAS), catalase (CAT), superoxide dismutase (SOD) and glutathione (GSH) levels of antioxidant parameters were measured. All patients received an adenotonsillectomy. Postoperative evaluation was performed at the 6th month. In the postoperative period, PSG, ECHO, ABPM and the oxidant-antioxidant parameter levels in the serum was repeated. RESULTS: Twenty-eight patients (13 males, 15 females; mean age 8.2 ± 2.06 years) were included in the study. In the preoperative period, concentric remodeling was observed in 14,8% of the patients, although they had no cardiovascular system complaints. The apnea-hypopnea index (AHI) scores were classified as mild in 39.3% (n = 11), moderate in 21.4% (n = 6) and severe in 39.3% (n = 11) preoperatively. In the postoperative period, 22 patients were evaluated. It was observed that the severity of OSAS decreased, ventricular functions improved, oxidant parameters decreased and antioxidant parameters increased postoperatively. CONCLUSION: Adenotonsillectomy provides a positive change in cardiovascular system parameters and an antioxidant change in the oxidative balance in patients with OSAS.

Negative refraction in terbium at ultraviolet frequencies.

One of the key challenges in the development of negative index metamaterials is creating a sufficiently strong magnetic response in the material. Rare-earth ions can contain a strong optical magnetic response even in the ultraviolet region of the spectrum, which can be enhanced using magneto-electric cross-coupling. Using energies, transition strengths, and linewidths from atomic structure software, along with realistic inhomogeneous broadenings and densities in a solid, we simulate a negative index scheme using a terbium crystal at a wavelength of 282 nm.

Prospects for continuous-wave molecular modulation in Raman-active microresonators.

We propose the extension of existing molecular modulation techniques for continuous-wave optical modulation to Raman-active microresonators. Intense pump and Stokes modes inside a microresonator prepare a high coherence of the Raman transition between two ro-vibrational states. With the coherence prepared, any laser in the optical region can be coupled to the microresonator and be modulated. We perform numerical simulations which predict that these "microresonator-based molecular modulators" could have modulation efficiencies on the order of 1% at 10 THz-scale frequencies for any optical wavelength.

The changing relationship between unemployment and total fertility.

The aim of this paper is to investigate whether there has been a fundamental change in the relationship between economic conditions and fertility. We use panel data methods to study the short-term changes in total fertility and the unemployment rate in a range of Organisation for Economic Co-operation and Development (OECD) countries from 1957 to 2014. We find that although fertility was counter-cyclical before 1970, with good economic times being associated with lower fertility, since then it has become pro-cyclical, with good economic times being associated with higher fertility.

Are serum leptin levels a prognostic factor in advanced lung cancer?

AIM: The aim of the present study was to evaluate pre-treatment concentrations of leptin in patients with advanced lung cancer and to investigate possible associations between their levels and clinicopathological variables, response to therapy and overall survival. MATERIAL AND METHODS: There are 71 previously untreated patients with cytological or histological evidence of primary lung cancer who were admitted to the oncology department between November 2013 and August 2014. Forty-five healthy individuals with age, sex and BMI matching the lung cancer patients, were recruited to take part in the study as a control group. Leptin levels were measured quantitatively by using a microELISA kit. RESULTS: The serum leptin levels at diagnosis were significantly lower in lung cancer patients than those in control subjects (4.75±4.91 ng/ml, 9.67±8.02 ng/ml; p<0.001). We did not find any significant difference in leptin values related to clinicopathological parameters such as ECOG PS, weight loss, histological type, disease stage and TNM classification. Nevertheless, we demonstrated a significant correlation between serum leptin levels and BMI in lung cancer patients (correlation coefficient: 0.303; p>0.010). The analysis of serum leptin values did not show any association with the overall survival of the patients. CONCLUSION: Our results showed that the serum leptin level has no prognostic indications in advanced lung cancer patients. Leptin is decreased in lung cancer, and there is lack of correlation with tumour­related factors including prognosis. Therefore, leptin is not a useful clinical marker in lung cancer (Tab. 2, Fig. 2, Ref. 22).

Swallowing dysfunction as a factor that should be remembered in recurrent pneumonia: videofluoroscopic swallow study.

BACKGROUND: The swallow function is one of the strong defense mechanism against aspiration. Aspiration and pneumonia are unavoidable in patients with defective mechanism of swallowing. The aim of this study was to evaluate patients with recurrent pneumonia in terms of videofluoroscopic examination results. METHODS: The study comprised fifty pediatric cases (22 boys, 28 girls) with an average age of 2.9 years (2 months-7.5 years) who were referred to our clinic due to suffering from recurrent pneumonia. The videofluoroscopic swallow study (VFSS) was performed on all patients. The presence of a correlation with pneumonia was investigated. RESULTS: In 45 of the children, VFSS results were not normal. Of the children, 41 had mental-motor retardation. The results of the videofluoroscopic study show that silent aspiration was the most common pathology in participants with the percentage of 40 (27.5% mild, 17.5% severe). Patients in the study had pneumonia with an incidence of 2.6 illnesses per year. Having one than more results on VFSS was found to be associated with more number of annual pneumonia episodes. CONCLUSIONS: Children with neurological impairments are at risk of recurrent acute pneumonia due to aspiration. Disturbances of swallowing phases should be remembered as a cause of pneumonia in these patients.

The influence of occlusion on masticatory performance and satisfaction in complete denture wearers.

Complete dentures should satisfy patients' needs for comfort, function and aesthetics. Thirty edentulous patients were enrolled in this study. Two sets of complete dentures were made for each patient: one with bilaterally balanced occlusion and the other with lingualised occlusion. The patients used each type of denture for 6 months. A single-blind study design was used in which the patients were not aware of the exchange of dentures. In each 3-month period, electromyographic measurements of the anterior temporalis and masseter muscles were performed. At the end of 6 months, patient satisfaction was evaluated. The second measurement of lingualised occlusion showed the greatest muscle activity, while chewing gum in both the anterior temporalis and masseter muscles (174·5 and 208·19 µV, respectively). The greatest maximum voluntary contraction was also found for the second measurement of lingualised occlusion for both the anterior temporalis and masseter muscles (142·91 and 187·55 µV, respectively). The mean chewing time decreased with lingualised occlusion. The percent distribution of the patients' ratings of their complete dentures and patient satisfaction with lingualised occlusion were higher than those for bilaterally balanced occlusion. Complete dentures with lingualised occlusion increased masticatory performance, maximum voluntary contraction and patient satisfaction and decreased chewing time.