AlGaN/GaN-HEMT power amplifiers with optimized power-added efficiency for X-band applications

This work has arisen out of the strong demand for a superior power-added efficiency (PAE) of AlGaN/GaN high electron mobility transistor (HEMT) high-power amplifiers (HPAs) that are part of any advanced wireless multifunctional RF-system with limited prime energy. Different concepts and approaches on device and design level for PAE improvements are analyzed, e.g. structural and layout changes of the GaN transistor and advanced circuit design techniques for PAE improvements of GaN HEMT HPAs

Onset and maintenance of psychiatric disorders after serious accidents

The purpose of this study was to prospectively investigate the onset, course, and remission of psychiatric disorders in the first 6months after a serious accident for consecutive patients in a hospital emergency department. Participants were 58 patients aged 18-65 who were assessed shortly after attending a hospital emergency department and were followed up 6months afterwards. Patients were interviewed with regard to past and current psychiatric history using different instruments (e.g. SCID for DSM-IV). Prior to their accidents, 35% of all subjects had experienced one or more psychiatric disorders (lifetime prevalence). Shortly after the accident, the incidence of Acute Stress Disorder (7%), subsyndromal Acute Stress Disorder (12%), and adjustment disorder (1.5%) was increased as a reaction to the accident. At this time, 29% of all patients suffered from an acute psychiatric disorder. Six-months after the accident, 10% of the subjects met criteria for Major Depression, 6% for PTSD, 4% for subsyndromal PTSD, and 1.5% for Specific Phobia as newly developed disorders. The course of the psychiatric disorders shows that those patients who met criteria for any psychiatric diagnosis shortly after the accident ran a much higher risk for developing new or comorbid psychiatric disorders in the futur

Cross-Sectional Analysis in the EPIC-Germany Study

Background Increased fibroblast growth factor 23 (FGF23), a bone-derived hormone involved in the regulation of phosphate and vitamin D metabolism, has been related to the development of cardiovascular disease (CVD) in chronic kidney disease patients and in the general population. However, what determines higher FGF23 levels is still unclear. Also, little is known about the influence of diet on FGF23. The aim of this study was therefore to identify demographic, clinical and dietary correlates of high FGF23 concentrations in the general population. Methods We performed a cross- sectional analysis within a randomly selected subcohort of the European Prospective Investigation into Cancer and Nutrition (EPIC)-Germany comprising 2134 middle-aged men and women. The Human FGF23 (C-Terminal) ELISA kit was used to measure FGF23 in citrate plasma. Dietary data were obtained at baseline via validated food frequency questionnaires including up to 148 food items. Results Multivariable adjusted logistic regression showed that men had a 66% lower and smokers a 64% higher probability of having higher FGF23 (≥ 90 RU/mL) levels compared, respectively, with women and nonsmokers. Each doubling in parathyroid hormone, creatinine, and C-reactive protein was related to higher FGF23. Among the dietary factors, each doubling in calcium and total energy intake was related, respectively, to a 1.75 and to a 4.41 fold increased probability of having higher FGF23. Finally, each doubling in the intake of iron was related to an 82% lower probability of having higher FGF23 levels. Results did not substantially change after exclusion of participants with lower kidney function. Conclusions In middle-aged men and women traditional and non-traditional CVD risk factors were related to higher FGF23 concentrations. These findings may contribute to the understanding of the potential mechanisms linking increased FGF23 to increased CVD risk

Obesity as risk factor for subtypes of breast cancer: results from a prospective cohort study

Background: Earlier epidemiological studies indicate that associations between obesity and breast cancer risk may not only depend on menopausal status and use of exogenous hormones, but might also differ by tumor subtype. Here, we evaluated whether obesity is differentially associated with the risk of breast tumor subtypes, as defined by 6 immunohistochemical markers (ER, PR, HER2, Ki67, Bcl-2 and p53, separately and combined), in the prospective EPIC-Germany Study (n = 27,012). Methods: Formalin-fixed and paraffin-embedded (FFPE) tumor tissues of 657 incident breast cancer cases were used for histopathological analyses. Associations between BMI and breast cancer risk across subtypes were evaluated by multivariable Cox regression models stratified by menopausal status and hormone therapy (HT) use. Results: Among postmenopausal non-users of HT, higher BMI was significantly associated with an increased risk of less aggressive, i.e. ER+, PR+, HER2-, Ki67low, Bcl-2+ and p53- tumors (HR per 5 kg/m2: 1.44 [1.10, 1.90], p = 0.009), but not with risk of more aggressive tumor subtypes. Among postmenopausal users of HT, BMI was significantly inversely associated with less aggressive tumors (HR per 5 kg/m2: 0.68 [0.50, 0.94], p = 0.018). Finally, among pre- and perimenopausal women, Cox regression models did not reveal significant linear associations between BMI and risk of any tumor subtype, although analyses by BMI tertiles showed a significantly lower risk of less aggressive tumors for women in the highest tertile (HR: 0.55 [0.33, 0.93]). Conclusion: Overall, our results suggest that obesity is related to risk of breast tumors with lower aggressiveness, a finding that requires replication in larger-scale analyses of pooled prospective data

AlGaN/GaN-HEMT power amplifiers with optimized power-added efficiency for X-band applications

This work has arisen out of the strong demand for a superior power-added efficiency (PAE) of AlGaN/GaN high electron mobility transistor (HEMT) high-power amplifiers (HPAs) that are part of any advanced wireless multifunctional RF-system with limited prime energy. Different concepts and approaches on device and design level for PAE improvements are analyzed, e.g. structural and layout changes of the GaN transistor and advanced circuit design techniques for PAE improvements of GaN HEMT HPAs

AlGaN/GaN-HEMT power amplifiers with optimized power-added efficiency for X-band applications

This work has arisen out of the strong demand for a superior power-added efficiency (PAE) of AlGaN/GaN high electron mobility transistor (HEMT) high-power amplifiers (HPAs) that are part of any advanced wireless multifunctional RF-system with limited prime energy. Different concepts and approaches on device and design level for PAE improvements are analyzed, e.g. structural and layout changes of the GaN transistor and advanced circuit design techniques for PAE improvements of GaN HEMT HPAs

Onset and maintenance of psychiatric disorders after serious accidents

The purpose of this study was to prospectively investigate the onset, course, and remission of psychiatric disorders in the first 6 months after a serious accident for consecutive patients in a hospital emergency department. Participants were 58 patients aged 18–65 who were assessed shortly after attending a hospital emergency department and were followed up 6 months afterwards. Patients were interviewed with regard to past and current psychiatric history using different instruments (e.g. SCID for DSM-IV). Prior to their accidents, 35% of all subjects had experienced one or more psychiatric disorders (lifetime prevalence). Shortly after the accident, the incidence of Acute Stress Disorder (7%), subsyndromal Acute Stress Disorder (12%), and adjustment disorder (1.5%) was increased as a reaction to the accident. At this time, 29% of all patients suffered from an acute psychiatric disorder. Six-months after the accident, 10% of the subjects met criteria for Major Depression, 6% for PTSD, 4% for subsyndromal PTSD, and 1.5% for Specific Phobia as newly developed disorders. The course of the psychiatric disorders shows that those patients who met criteria for any psychiatric diagnosis shortly after the accident ran a much higher risk for developing new or comorbid psychiatric disorders in the future