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Silicon microspheres for wavelength division multiplexing in the THz band - art. no. 61250T
No full textMicrospheres possess high quality factor morphology-dependent resonances, i.e., whispering gallery modes. Additionally, silicon is proving itself to be an excellent optical material. We have studied the feasibility of silicon microspheres as a optical filters at THz communication frequencies. The silicon microsphere has a radius of 500 gm and a refractive index of 3.4. Elastic scattering spectra are calculated for TE and TM polarizations for wavelengths between 90 mu m and 100 mu m in the THz communication band. The high quality factor morphology dependent resonances are found to have a repetitive mode spacing of 1.2 mu m
Self-Q-Switched Cr:LiCAF laser near 800 nm
No full textSelf-Q-switching (SQS) of lasers enable the generation of Q-switched pulses from simple laser cavities without using any additional saturable absorbers or active modulators. Earlier studies have reported SQS in ruby, Nd:YAG, and Cr:LiSAF lasers. However, these systems were mostly flashlamp pumped and required cooling of the crystal and/or misalignment of the laser cavity for the observation of SQS. In this presentation, for the first time to our knowledge, we report SQS operation of a Cr:LiCAF laser. SQS was achieved in an astigmatically compensated x-cavity containing only a Cr:LiCAF crystal that was end-pumped with a 130-mW continuous-wave (cw) diode at 660 nm. During regular cw operation, the laser produced a diffraction-limited beam with 50 mW of output power and had a spectral width of 0.5 nm near 795 nm. SQS operation of the Cr:LiCAF laser could be initiated by fine adjustment of the separation between the curved mirrors of the cavity and was observed at several mirror separations within the stability range of the resonator. During SQS operation, the laser generated pulses with about 5 microsecond duration in the 780-800 nm wavelength range, at repetition rates between 10 and 30 kHz. SQS operation was further accompanied with a decrease in the output power to the 30-45 mW range. In this regime, the output beam became multimode and spectral broadening up to 12.5 nm (FWHM) was observed
Comparison of multichannel intraluminal impedance-pH monitoring and reflux scintigraphy in pediatric patients with suspected gastroesophageal reflux
No full textAIM To evaluate the agreement of multichannel intraluminal impedance-pH monitoring (MII-pHM) and gastroesophageal reflux scintigraphy (GES) for the diagnosis of gastroesophageal reflux disease. METHODS Seventy-five consecutive patients with suspected gastroesophageal reflux disease (GERD) underwent 24-h combined MII-pHM recording and one hour radionuclide scintigraphy during the course of the MII-pHM study. Catheters with 6 impedance channels and 1 pH sensor were placed transnasally. Impedance and pH data analysis were performed automatically and manually. For impedance monitoring, reflux was defined as a retrograde 50% drop in impedance, starting distally and propagating retrogradely to at least the next two more proximal measuring channels. Reflux index (RI, percentage of the entire record that esophageal pH is < 4.0) greater than 4.2% for pHM and number of refluxes more than 50 for 24 h for MII were accepted as positive test results. At scintigraphy, 240 frames of 15 seconds duration were acquired in the supine position. Gastroesophageal reflux was defined as at least one reflux episode in the esophagus. After scintigraphic evaluation, impedance-pH recordings and scintigraphic images were evaluated together and agreement between tests were evaluated with Cohen's kappa. RESULTS Sufficient data was obtained from 60 (80%) patients (34 male, 56.7%) with a mean age of 8.7 +/- 3.7 years (range: 2.5-17.3 years; median: 8.5 years). Chronic cough, nausea, regurgitation and vomiting were the most frequent symptoms. The mean time for recording of MII-pHM was 22.8 +/- 2.4 h (range: 16-30 h; median: 22.7 h). At least one test was positive in 57 (95%) patients. According to diagnostic criteria, GERD was diagnosed in 34 (57.7%), 44 (73.3%), 47 (78.3%) and 51 (85%) patients by means of pHM, MII, GES and MII-pHM, respectively. The observed percentage agreements/kappa values for GES and pHM, GES and MII, GES and MII-pHM, and MII and pHM are 48.3%/-0.118; 61.7%/-0.042; 73.3%/0.116 and 60%/0.147, respectively. There was no or slight agreement between GES and pHM alone, MII alone or MII-pHM. pH monitoring alone missed 17 patients compared to combined MII-pHM. The addition of MII to pH monitoring increased the diagnosis rate by 50%. CONCLUSION No or slight agreement was found among pH monitoring, MII monitoring, MII-pH monitoring and GES for the diagnosis of gastroesophageal reflux disease
Long time scale molecular dynamics subspace integration method applied to anharmonic crystals and glasses
No full textA subspace dynamics method is presented to model long time dynamical events. The method involves determining a set of vectors that span the subspace of the long time dynamics. Specifically, the vectors correspond to real and imaginary low frequency normal modes of the condensed phase system. Most importantly, the normal mode derived vectors are only used to define the subspace of low frequency motions, and the actual time dependent dynamics is fully anhannonic. The resultant projected set of Newton's equations is numerically solved for the subspace motions. Displacements along the coordinates outside the subspace are then constrained during the integration of the equations of motion in the reduced dimensional space. The method is different from traditional constraint methods in that it can systematically deduce and remove both local and collective high frequency motions of the condensed phase system with no a priori assumptions. The technique is well suited to removing large numbers of degrees of freedom, while only keeping the very low frequency global motions. The method is applied to highly anhannonic Lennard-Jones crystal and glass systems. Even in these systems with no intramolecular degrees of freedom or obvious separation of time scales, the subspace dynamics provides a speed up of approximately a factor of 5 over traditional molecular dynamics through use of a larger integration time step. In the cases illustrated here a single set of subspace vectors was adequate over the full time interval, although this is not expected to be true for all systems
Commercial research at universities and career choices of science and engineering doctoral students
No full textIntroduction: Herbal medicines are used for different purposes by applying them directly to the skin. Case Report: A 57-year-old female patient presented with erythema and swelling of the left knee. On examination, erythematous and bullous lesions were observed. In the story of 'Ranunculus Scleratus' plants 12 hours knee closed contact of the learned. Diagnosis; Fitokontakt thought of as Dermatitis patients to wet dressing is recommended. 1 month after hyperemia outside of a clinical finding out. Conclusion: Treatment with plants in our community are used as often as incorrect use can lead to harmful effects
Application of stochastic flows to the sticky Brownian motion equation
No full textWe investigate the relationship between the levels of industry collaboration and entrepreneurial activities at universities and the employment choices of their science and engineering doctoral students. Using data from 176 U.S. universities over the period 1996-2005, we document that more interaction with industry at a university is typically associated with more of the university's doctoral students choosing industry employment. We also document a positive relationship between universities' licenses and startups and their graduates' post-doctoral study choices
Association between gene polymorphisms in TIM1, TSLP, IL18R1 and childhood asthma in Turkish population
No full textMany immunologic and inflammatory mechanisms play a role in asthma etiology. The aim of this study was to investigate the susceptibility of asthma patients in the Turkish population with demonstrating genes for polymorphisms in TIM1, TSLP and IL18R1. All of the genomic DNA samples were isolated from blood samples according to a standard salting-out protocol. DNA samples were stored at -20 degrees C until the genotype analysis was performed. rs3806933 (TSLP -847 C > T) and TIM1 -416G > C were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The rs3806933 (TSLP -847 C > T) was genotyped by PCR using our new primers and HphI restriction enzyme digestion. rs2287033 (IL18R1 c. 1270+150 A > G), rs3213733 (IL18R1 c. 626-196 G > T), and rs3771166 (IL18R1-c. 302+1694 C > T) were genotyped using SYBR green dye based real time PCR assay. Results: The allele frequencies of 5 SNPs in TSLP, TIM-1, and IL18R1 genes were determined in 139 asthmatic patients and 126 healthy controls of in Turkish population. The investigated SNPs are as follows; rs3806933 (TSLP -847 C > T), TIM1 -416G > C, rs2287033 (IL18R1 c. 1270+150 A > G), rs3213733 (IL18R1 c. 626-196 G > T), and rs3771166 (IL18R1-c. 302+1694 C > T). Results suggest that IL18R1 c. 626-196 G > T (rs3213733) and TIM1 -416G > C are significantly associated with asthma in patients in Turkish population. Patients with AA genotypes of rs2287033 (IL18R1 c. 1270+150 A > G), have significantly less total serum IgE levels when compared with patients having GG or GA genotypes (p < 0.012; 381.77 +/- 239.46 vs 557.52 +/- 549.96, respectively). Conclusion: This study showed that IL18R1 c. 626 -196 G > T (rs3213733) and TIM1 -416G > C are significantly associated with asthma patients in Turkish population
Ablation of idiopathic ventricular tachycardia originating from posterior mitral annulus by using electroanatomical mapping
No full textIdiopathic ventricular tachycardia (IVT) is an important type of arrhythmia, which has distinct electrocardiographic features and treatment options. Most of the cases originate from right ventricular outflow tract and less frequently from the left ventricular outflow tract. IVTs originating from mitral annulus are rare, and little is known about the efficacy of radiofrequency catheter ablation in this form. We hereby present a rare case of IVT arising from posterior mitral annulus. The electrocardiographic, electrophysiological, and electroanatomical characteristics of this tachycardia are discussed
Modulated and continuous-wave operations of low-power thulium (Tm:YAP) laser in tissue welding
No full textOur aim is to explore the welding capabilities of a thulium (Tm:YAP) laser in modulated and continuous-wave (CW) modes of operation. The Tm: YAP laser system developed for this study includes a Tm: YAP laser resonator, diode laser driver, water chiller, modulation controller unit, and acquisition/control software. Full-thickness incisions on Wistar rat skin were welded by the Tm: YAP laser system at 100 mW and 5 s in both modulated and CW modes of operation (34.66 W/cm(2)). The skin samples were examined during a 21-day healing period by histology and tensile tests. The results were compared with the samples closed by conventional suture technique. For the laser groups, immediate closure at the surface layers of the incisions was observed. Full closures were observed for both modulated and CW modes of operation at day 4. The tensile forces for both modulated and CW modes of operation were found to be significantly higher than the values found by conventional suture technique. The 1980-nm Tm: YAP laser system operating in both modulated and CW modes maximizes the therapeutic effect while minimizing undesired side effects of laser tissue welding. Hence, it is a potentially important alternative tool to the conventional suturing technique
Electron microscopic evaluation of the secretory mechanisms of Renin from juxtaglomerular cells
No full textAlthough the structure and the functions of juxtaglomerular cells (JG) have been well defined, there is still a controversy about the secretory mechanisms of renin from these cells. It has been assumed that exocytosis is the main secretory mechanism in these cells in many studies, while others suggest that secretion occurs in a quite different way in these cells. There are several studies suggesting that diacrine secretion, which is very difficult to visualize, might be the other mechanism for secretion of renin. This study is an attempt to find the answers of these questions by identifying the fine structural features of the secretory granules in juxtaglomerular cells. Cyclosporin A (CyA) has been used in the current experimental study since it has already been reported that this drug increases the number of JG cells and stimulates secretion of Renin. Twelve female Sprague-Dawley rats had daily intraperitoneal injections of CyA for ten weeks. Tissue specimens from the kidneys of these animals were examined by electron microscopy. Fine structural characteristics of the secretory granules of juxtaglomerular cells have been examined. Considerable amount of granules, which goes to the exocytotic process, have been observed. Additionally, several cells, which their granules had been secreting their contents in a different way, were found. This was interpreted as the secretion type of diacrine secretion. In conclusion, this in vivo study presents morphologic evidences demonstrating that both exocytosis and diacrine secretion might occur in JG cells. We also had a chance to observe secretory granule probably exhibiting "diacrine secretion", which is very difficult to visualize, at electron microscope level for the first time. This report also provides morphologic proof which shows that these two distinct secretory mechanisms might occur simultaneously in the same juxtaglomerular cell