Proof of Concept of a New Glucose Sensing Technology: Color-Changing Hydrogels Including au Nanoparticles

This Master thesis provides a proof of concept for a novel, implantable continuous glucose sensing technology. Immobilized glucose oxidase in a poly 2-hydroxyethyl methacrylate hydrogel is used to enzymatically convert an increase in glucose level to a local decrease in pH, which leads to a swelling of the hydrogel. Encapsulated gold nanoparticles in the gel allow an optical readout of the glucose concentration. Experimental methods include hydrogel synthesis, nanoparticle encapsulation and finally glucose sensing with the hydrogel by UV-vis measurements. Two possible readouts, absorbance change and frequency shift, are discussed and tested. While a frequency shift is not detected, results show that the absorbance of the gel is proportional to glucose level, making it a promising concept for continuous glucose monitoring

Benefits of robotic cystectomy with intracorporeal diversion for patients with low cardiorespiratory fitness: a prospective cohort study

Background: Patients undergoing radical cystectomy have associated comorbidities resulting in reduced cardiorespiratory fitness. Preoperative cardiopulmonary exercise testing (CPET) measures including anaerobic threshold (AT) can predict major adverse events (MAE) and hospital length of stay (LOS) for patients undergoing open and robotic cystectomy with extracorporeal diversion. Our objective was to determine the relationship between CPET measures and outcome in patients undergoing robotic radical cystectomy and intracorporeal diversion (intracorporeal robotic assisted radical cystectomy [iRARC]). Methods: A single institution prospective cohort study in patients undergoing iRARC for muscle invasive and high-grade bladder cancer. Inclusion: patients undergoing standardised CPET before iRARC. Exclusions: patients not consenting to data collection. Data on CPET measures (AT, ventilatory equivalent for carbon dioxide [VE/VCO2] at AT, peak oxygen uptake [VO2]), and patient demographics prospectively collected. Outcome measurements included hospital LOS; 30-day MAE and 90-day mortality data, which were prospectively recorded. Descriptive and regression analyses were used to assess whether CPET measures were associated with or predicted outcomes. Results: From June 2011 to March 2015, 128 patients underwent radical cystectomy (open cystectomy, n = 17; iRARC, n = 111). A total of 82 patients who underwent iRARC and CPET and consented to participation were included. Median (interquartile range): age = 65 (58–73); body mass index = 27 (23–30); AT = 10.0 (9–11), Peak VO2 = 15.0 (13–18.5), VE/VCO2 (AT) = 33.0 (30–38). 30-day MAE = 14/111 (12.6%): death = 2, multiorgan failure = 2, abscess = 2, gastrointestinal = 2, renal = 6; 90-day mortality = 3/111 (2.7%). AT, peak VO2, and VE/VCO2 (at AT) were not significant predictors of 30-day MAE or LOS. The results are limited by the absence of control group undergoing open surgery. Conclusions: Poor cardiorespiratory fitness does not predict increased hospital LOS or MAEs in patients undergoing iRARC. Overall, MAE and LOS comparable with other series

Towards a Novel Generalized Chinese Remainder Algorithm for Extended Rabin Cryptosystem

This paper proposes a number of theorems and algorithms for the Chinese Remainder Theorem, which is used to solve a system of linear congruences, and the extended Rabin cryptosystem, which accepts a key composed of an arbitrary finite number of distinct primes. This paper further proposes methods to relax the condition on the primes with trade-offs in the time complexity. The proposed algorithms can be used to provide ciphertext indistinguishability. Finally, this paper conducts extensive experimental analysis on six large data sets. The experimental results show that the proposed algorithms are asymptotically tight to the existing decryption algorithm in the Rabin cryptosystem with the key composed of two distinct primes while maintaining increased generality

Decreased Axon Caliber Underlies Loss of Fiber Tract Integrity, Disproportional Reductions in White Matter Volume, and Microcephaly in Angelman Syndrome Model Mice

Angelman syndrome (AS) is a debilitating neurodevelopmental disorder caused by loss of function of the maternally inherited UBE3A allele. It is currently unclear how the consequences of this genetic insult unfold to impair neurodevelopment. We reasoned that by elucidating the basis of microcephaly in AS, a highly penetrant syndromic feature with early postnatal onset, we would gain new insights into the mechanisms by which maternal UBE3A loss derails neurotypical brain growth and function. Detailed anatomical analysis of both male and female maternal Ube3a-null mice reveals that microcephaly in the AS mouse model is primarily driven by deficits in the growth of white matter tracts, which by adulthood are characterized by densely packed axons of disproportionately small caliber. Our results implicate impaired axon growth in the pathogenesis of AS and identify noninvasive structural neuroimaging as a potentially valuable tool for gauging therapeutic efficacy in the disorder

Mid-IR heterogeneous silicon photonics

In this paper we discuss silicon-based photonic integrated circuit technology for applications beyond the telecommunication wavelength range. Silicon-on-insulator and germanium-on-silicon passive waveguide circuits are described, as well as the integration of III-V semiconductors, IV-VI colloidal nanoparticle films and GeSn alloys on these circuits for increasing the functionality. The strong nonlinearity of silicon combined with the low nonlinear absorption in the mid-infrared is exploited to generate picosecond pulse based supercontinuum sources and optical parametric oscillators that can be used as spectroscopic sensor sources

The Complete Star Formation History of the Universe

The determination of the star-formation history of the Universe is a key goal of modern cosmology, as it is crucial to our understanding of how structure in the Universe forms and evolves. A picture has built up over recent years, piece-by-piece, by observing young stars in distant galaxies at different times in the past. These studies indicated that the stellar birthrate peaked some 8 billion years ago, and then declined by a factor of around ten to its present value. Here we report on a new study which obtains the complete star formation history by analysing the fossil record of the stellar populations of 96545 nearby galaxies. Broadly, our results support those derived from high-redshift galaxies elsewhere in the Universe. We find, however, that the peak of star formation was more recent - around 5 billion years ago. Our study also shows that the bigger the stellar mass of the galaxy, the earlier the stars were formed. This striking result indicates a very different formation history for high- and low-mass formation.Comment: Accepted by Nature. Press embargo until publishe

Controlled comparison of hemodialysis and peritoneal dialysis: Veterans Administration multicenter study

Controlled comparison of hemodialysis and peritoneal dialysis: Veterans Administration multicenter study. We measured mortality and morbidity among 114 patients assigned randomly to home hemodialysis (HD) and home intermittent peritoneal dialysis (IPD). Data were collected during the time of home training and for 12 months after initiation of home dialysis. Training time was shorter for the IPD than for the HD patients (P < 0.001) with median time 1.8 months for IPD and 3.9 months for HD. Switching to the alternative mode of treatment was more frequent for the IPD group (29/59 vs. 5/55, P < 0.001). Survival time was not different, perhaps because of the modality change. More IPD patients were hospitalized in the first 6 months (20 for IPD vs. 9 for HD, P = 0.02), but they had fewer troublesome cardiovascular events in the first year (0 vs. 12, P < 0.001). The HD patients maintained better nutritional status as reflected in body weight and arm muscle circumference and possibly in urea appearance rate. Thus, these data suggest that for most patients, IPD is a less satisfactory form of therapy than HD, but certain advantages of IPD did emerge. Applications of this information to the currently more popular mode of CAPD await further study.Comparaison contrôlée entre l'hémodialyse et la dialyse péritonéale: Étude multicentrique de l'Administration des Veterans. Nous avons mesuré la mortalité et la morbidité chez 114 malades, pris au hasard, en hémodialyse à domicile (HD) ou en dialyse péritonéale intermittente à domicile (IPD). Les données ont été recueillies pendant l'entrainement à domicile et pendant les 12 mois suivant le début de la dialyse à domicile. La durée d'entrainement était plus brève pour les malades en IPD que pour ceux en HD (P < 0,001), avec un temps médian de 1,8 mois pour l'IPD et de 3,9 mois pour l'HD. Le changement pour l'autre mode de traitement était plus fréquent pour le groupe IPD (29/59 contre 5/55, P < 0,001). La durée de suivi n'était pas différente, peut-être à cause du changement de modalité. Plus de malades en IPD ont été hospitalisés dans les 6 premiers mois (20 en IPD, contre 9 en HD, P = 0,02), mais ils ont eu moins d'ennuis cardiovasculaires gênants au cours de la première année (0 contre 12, P < 0,001). Les malades HD conservaient un meilleur état nutritionnel, reflété par le poids corporel, la circonférence musculaire du bras, et probablement la vitesse d'apparition de l'urée. Ainsi ces données suggèrent que pour la plupart des malades, l'IPD est une forme de traitement moins satisfaisante que l'HD, mais certains avantages de l'IPD sont apparus. Les applications de cette information au mode actuellement le plus répandu de CAPD requièrent d'autres études