Nanoscale charging hysteresis measurement by multifrequency electrostatic force spectroscopy

We report a scanning probe technique that can be used to measure charging of localized states on conducting or partially insulating substrates at room temperature under ambient conditions. Electrostatic interactions in the presence of a charged particle between the tip and the sample is monitored by the second order flexural mode, while the fundamental mode is used for stabilizing the tip-sample separation. Cycling the bias voltage between two limits, it is possible to observe hysteresis of the second order mode amplitude due to charging. Results are presented on silicon nitride films containing silicon nanocrystals. © 2008 American Institute of Physics

A complication of pectus excavatum operation: Endomyocardial steel strut

An 18-year-old patient who had correction of pectus excavatum deformity in our department 4 years earlier was admitted because of stabbing chest pain. He had not attended to postoperative controls and had not come for extraction of the steel strut, although he had been contacted. He was diagnosed to have a broken steel strut, and the shut was noted to be embedded in the myocardium. This unreported complication of pectus excavatum operation forced us to review sternal support techniques. (Ann Thorac Surg 1999;68:1082-3) (C) 1999 by The Society of Thoracic Surgeons

The effectiveness of levothyroxine suppressive therapy in patients with multinodular goiter

The use of thyroid hormone for suppression therapy of multinodular goiter is controversial. The aim of this study is to evaluate the efficacy of levothyroxine suppression therapy in patients with multinodular goiter. Ninety-five patients with multinodular goiter treated between September 1994 and December 1996 were prospectively evaluated. The patients ere divided into groups. Group I consisted of fifty-three patients and the patients in group II and the patients in this group received levothyroxine, 100 mg per day. The baseline serum TSH levels were kept between 0.1-0.5 mU/L range during the suppression therapy. Ultrasonography was used to measure the diameter of the dominant thyroid nodules before and after therapy. The length of follow-up was 12 months. After 1 year of follow-up, statistically significant difference in the reduction rate of the diameter of dominant nodules was demonstrated between the two groups (p0.05). Subclinical hyperthyroidis was detected in six of the patients in the group which received suppression therapy. In conclusion, in spite of the demonstration of significant nodule diameter reduction, we do not advocate thyroid hormone suppression therapy in patients with multinodular goiter, because there were no significant difference in increment of diameter of overall attention of the nodules, and because of the potential disadvantages such as obligation of long-term usage and subclinical hyperthyroidism, especially in old and postmenopausal patients

Gain and transient photoresponse of quantum well infrared photodetectors: A detailed ensemble Monte Carlo study

We investigate different gain characteristics observed on quantum well infrared photodetectors (QWIPs) fabricated with various material systems, and the effects of barrier material properties on the device characteristics through detailed ensemble Monte Carlo simulations. When the energy spacing between the central and satellite valleys is increased, the improvement in the excited electron lifetime is found to be much stronger than that in the average electron velocity in the device. According to our results, relatively high gain observed in InP/In0.53Ga0.47As QWIPs under large bias is not due to the higher mobility in InP as suggested earlier; it can mainly be attributed to higher excited electron lifetime as a result of relatively large Γ–L energy spacing. We discuss the details of the fast part of the Al0.3Ga0.7As/GaAs QWIP transient photoresponse, which exhibits three regions with different decay characteristics under a short pulse of radiation. The duration of the final region, during which the electrons excited near the emitter are extracted from the collector, is observed to be considerably long due to the dispersion of the photoelectrons. The photoresponse time rapidly decreases with increasing bias under low bias, and nearly saturates at ∼10 ps under large bias being ∼40% larger than the average transit time estimated by dividing the device length to the average steady-state electron velocity in device. We also investigate the effects of the interface reflections on the photoresponse time

A detailed ensemble Monte Carlo study of the effect of quantum well width on quantum well infrared photodetector characteristics

We present a simulation based investigation of the dependence of the device characteristics on the quantum well width in AlGaAs/GaAs quantum well infrared photodetectors (QWIPs) through the ensemble Monte Carlo technique. The simulations on two different standard Al0.3Ga0.7As/GaAs QWIPs with quantum well widths of 36 and 44 Å have shown that the gain in the former is considerably higher, which is due to much longer lifetime of the photoexcited electrons as a result of lower capture probability in the device. We discuss this observation by the investigation of the electron scattering rates in these structures through realistically evaluated scattering mechanisms between two and three-dimensional states in the multi-quantum well structur

Effects of Thyroid Hormone Therapy on Cut-Surface Healing of the Remnant Stomach with Short-Term Weight Loss Alterations after Sleeve Gastrectomy

PMID = 2863551

A Preventive Strategy for Staple Line Bleeding in Morbidly Obese Patients Undergoing Sleeve Gastrectomy

PMID = 2882922

period living in low and high socio-economic areas in Denizli, Turkey

Objective: Immunity against rubella before women's reproductive age is a practical strategy to control congenital rubella syndrome (CRS). This study was designed to investigate the rubella seroprevalance among the female primary-school students living in low and high socio-economic areas in Denizli (Turkey).Methodology: Two hundred seventy seven students were eligible for this comparative cross-sectional study (November 2003). Schools and classrooms were randomly included in the sample. The cut off points of blood sample were set as <10 IU negative; (3)10 - <15 IU indeterminate; 315 IU positive.Results: Study was completed in 235 (84.8%) students. Rubella seropositivity was 74.0% (p=0.03). Rubella vaccination rate was 14.0% (high SES) and 7.8% (low SES). A significant difference continued among the graders even after multivariable adjustments (p<0.001).Conclusion: Sporadic rubella vaccinations may not be a right option to control rubella among women in their reproductive age thus active immunization is important for public health in developing countries

period living in low and high socio-economic areas in Denizli, Turkey

Objective: Immunity against rubella before women's reproductive age is a practical strategy to control congenital rubella syndrome (CRS). This study was designed to investigate the rubella seroprevalance among the female primary-school students living in low and high socio-economic areas in Denizli (Turkey).Methodology: Two hundred seventy seven students were eligible for this comparative cross-sectional study (November 2003). Schools and classrooms were randomly included in the sample. The cut off points of blood sample were set as <10 IU negative; (3)10 - <15 IU indeterminate; 315 IU positive.Results: Study was completed in 235 (84.8%) students. Rubella seropositivity was 74.0% (p=0.03). Rubella vaccination rate was 14.0% (high SES) and 7.8% (low SES). A significant difference continued among the graders even after multivariable adjustments (p<0.001).Conclusion: Sporadic rubella vaccinations may not be a right option to control rubella among women in their reproductive age thus active immunization is important for public health in developing countries