Optically-pumped saturable absorber for fast switching between continuous-wave and passively mode-locked regimes of a Nd:YVO4 laser

We report on the fast (~50 μs) remote-controlled switching between continuous-wave (cw), cw mode-locked (ML) and Q-switched ML modes of operation of a Nd:YVO4 laser using an optically-pumped saturable absorber (SA). Pulses as short as 40 ps with an average output power of 0.5 W are obtained in cw ML regime

Educational Level Is Related to Physical Fitness in Patients with Type 2 Diabetes - A Cross-Sectional Study.

Low educational level (EL) and low physical fitness are both predictors of increased morbidity and mortality in patients with type 2 diabetes. It is unknown if EL is related to physical fitness. This would have important implication for the treatment approach of patients of low EL. In 2011/12, we invited participants of a new nationwide Swiss physical activity program for patients with type 2 diabetes to participate in this study. EL was defined by self-report and categorized as low (mandatory education), middle (professional education) or high (high school/university). Physical fitness was determined using 5 validated measures that assessed aerobic fitness, functional lower limb muscle strength, walking speed, balance and flexibility. Potential confounder variables such as other socio-cultural factors, physical activity level, body composition, diabetes-related parameters and complications/co-morbidities as well as well-being were assessed. All invited 185 participants (mean age 59.6 ±9.8 yrs, 76 women) agreed to be included. Of all patients, 23.1% had a low, 32.7% a middle and 44.2% a high EL; 41.8% were professionally active. The study population had a mean BMI of 32.4±5.2 kg/m2 and an HbA1c of 7.3±1.3%. The mean diabetes duration was 8.8±7.4 years. In the baseline assessment, higher EL was associated with increased aerobic fitness, increased functional lower limb muscle strength, and increased walking speed using linear regression analysis (values for low, middle and high EL, respectively: 91.8 ± 27.9, 116.4 ± 49.7 and 134.9 ± 60.4 watts for aerobic fitness (p = 0.002), 15 ± 4.7, 13.9 ± 2.7, 12.6 ± 2.9 seconds for strength (p = 0.001) and 8.8 ± 1.6, 8.3 ± 1.4, 7.8 ± 1.4 seconds for walking speed (p = 0.004)). These associations were independent of potential confounders. Overall, aerobic fitness was 46%, functional limb muscle strength 16%, and walking speed 11% higher in patients of high compared to those of low EL. EL was not related to balance or flexibility. A main strength of the present study is that it addresses a population of importance and a factor (EL) whose understanding can influence future interventions. A second strength is its relatively large sample size of a high-risk population. Third, unlike studies that have shown an association between self-reported fitness and educational level we assessed physical fitness measures by a quantitative and validated test battery using assessors blinded to other data. Another novelty is the extensive evaluation of the role of many relevant confounder variables. In conclusion, we show that in patients with type 2 diabetes EL correlates favorably and independently with important health-related physical fitness measures such as aerobic fitness, walking speed, and lower limb strength. Our findings underline that diabetic patients with low EL should be specifically encouraged to participate in physical activity intervention programs to further reduce social disparities in healthcare. Such programs should be structured and integrate the norms, needs and capacities (financial, time, physical capacities and self-efficacy) of this population, and their effectiveness should be tested in future studies. University of Lausanne clinicaltrials.gov NCT01289587

Effect of Arteriovenous Anastomosis on Blood Pressure Reduction in Patients With Isolated Systolic Hypertension Compared With Combined Hypertension

Background: Options for interventional therapy to lower blood pressure (BP) in patients with treatment‐resistant hypertension include renal denervation and the creation of an arteriovenous anastomosis using the ROX coupler. It has been shown that BP response after renal denervation is greater in patients with combined hypertension (CH) than in patients with isolated systolic hypertension (ISH). We analyzed the effect of ROX coupler implantation in patients with CH as compared with ISH. Methods and Results: The randomized, controlled, prospective ROX Control Hypertension Study included patients with true treatment‐resistant hypertension (office systolic BP ≥140 mm Hg, average daytime ambulatory BP ≥135/85 mm Hg, and treatment with ≥3 antihypertensive drugs including a diuretic). In a post hoc analysis, we stratified patients with CH (n=31) and ISH (n=11). Baseline office systolic BP (177±18 mm Hg versus 169±17 mm Hg, P=0.163) and 24‐hour ambulatory systolic BP (159±16 mm Hg versus 154±11 mm Hg, P=0.463) did not differ between patients with CH and those with ISH. ROX coupler implementation resulted in a significant reduction in office systolic BP (CH: −29±21 mm Hg versus ISH: −22±31 mm Hg, P=0.445) and 24‐hour ambulatory systolic BP (CH: −14±20 mm Hg versus ISH: −13±15 mm Hg, P=0.672), without significant differences between the two groups. The responder rate (office systolic BP reduction ≥10 mm Hg) after 6 months was not different (CH: 81% versus ISH: 82%, P=0.932). Conclusions: Our data suggest that creation of an arteriovenous anastomosis using the ROX coupler system leads to a similar reduction of office and 24‐hour ambulatory systolic BP in patients with combined and isolated systolic hypertension. Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01642498

The enzymatic activity of the VEGFR2-receptor for the biosynthesis of dinucleoside polyphosphates

The group of dinucleoside polyphosphates encompasses a large number of molecules consisting of two nucleosides which are connected by a phosphate chain of variable length. While the receptors activated by dinucleoside polyphosphates as well as their degradation have been studied in detail, its biosynthesis has not been elucidated so far. Since endothelial cells released the dinucleoside polyphosphate uridine adenosine tetraphosphate (Up4A), we tested cytosolic proteins of human endothelial cells obtained from dermal vessels elicited for enzymatic activity. When incubated with ADP and UDP, these cells showed increasing concentrations of Up4A. The underlying enzyme was isolated by chromatography and the mass spectrometric analysis revealed that the enzymatic activity was caused by the vascular endothelial growth factor receptor 2 (VEGFR2). Since VEGFR2 but neither VEGFR1 nor VEGFR3 were capable to synthesise dinucleoside polyphosphates, Tyr-1175 of VEGFR2 is most likely essential for the enzymatic activity of interest. Further, VEGFR2-containing cells like HepG2, THP-1 and RAW264.7 were capable of synthesising dinucleoside polyphosphates. VEGFR2-transfected HEK 293T/17 but not native HEK 293T/17 cells synthesised dinucleoside polyphosphates in vivo too. The simultaneous biosynthesis of dinucleoside polyphosphates could amplify the response to VEGF, since dinucleoside polyphosphates induce cellular growth via P2Y purinergic receptors. Thus the biosynthesis of dinucleoside polyphosphates by VEGFR2 may enhance the proliferative response to VEGF. Given that VEGFR2 is primarily expressed in endothelial cells, the biosynthesis of dinucleoside polyphosphates is mainly located in the vascular system. Since the vasculature is also the main site of action of dinucleoside polyphosphates, activating vascular purinoceptors, blood vessels appear as an autocrine system with respect to dinucleoside polyphosphates. We conclude that VEGFR2 receptor is capable of synthesising dinucleoside polyphosphates. These mediators may modulate the effects of VEGFR2 due to their proliferative effects

Vertical-external-cavity surface-emitting lasers and quantum dot lasers

The use of cavity to manipulate photon emission of quantum dots (QDs) has been opening unprecedented opportunities for realizing quantum functional nanophotonic devices and also quantum information devices. In particular, in the field of semiconductor lasers, QDs were introduced as a superior alternative to quantum wells to suppress the temperature dependence of the threshold current in vertical-external-cavity surface-emitting lasers (VECSELs). In this work, a review of properties and development of semiconductor VECSEL devices and QD laser devices is given. Based on the features of VECSEL devices, the main emphasis is put on the recent development of technological approach on semiconductor QD VECSELs. Then, from the viewpoint of both single QD nanolaser and cavity quantum electrodynamics (QED), a single-QD-cavity system resulting from the strong coupling of QD cavity is presented. A difference of this review from the other existing works on semiconductor VECSEL devices is that we will cover both the fundamental aspects and technological approaches of QD VECSEL devices. And lastly, the presented review here has provided a deep insight into useful guideline for the development of QD VECSEL technology and future quantum functional nanophotonic devices and monolithic photonic integrated circuits (MPhICs).Comment: 21 pages, 4 figures. arXiv admin note: text overlap with arXiv:0904.369

A Method for Analyzing the Ubiquitination and Degradation of Aurora-A

The cell cycle machinery consists of regulatory proteins that control the progression through the cell cycle ensuring that DNA replication alternates with DNA segregation in mitosis to maintain cell integrity. Some of these key regulators have to be degraded at each cell cycle to prevent cellular dysfunction. Mitotic exit requires the inactivation of cyclin dependent kinase1 (cdk1) and it is the degradation of the cyclin subunit that inactivates the kinase. Cyclin degradation has been well characterized and it was shown that it is ubiquitin proteasome pathway that leads to the elimination of cyclins. By now, many other regulatory proteins were shown to be degraded by the same pathway, among them members of the aurora kinase family, degraded many other regulatory proteins. Aurora kinases are involved in mitotic spindle formation as well as in cytokinesis. The abundance and activity of the kinase is precisely regulated during the cell cycle. To understand how proteolysis regulates transitions through the cell cycle we describe two assays for ubiquitination and degradation of xenopus aurora kinase A using extracts from xenopus eggs or somatic cell lines

The Chromosomal Passenger Complex Activates Polo Kinase at Centromeres

INCENP acts as a protein scaffold that integrates the functions of two crucial mitotic kinases, Aurora B and Polo, at centromeres of mitotic chromosomes