Changes in labial capillary density on ascent to and descent from high altitude

Present knowledge of how the microcirculation is altered by prolonged exposure to hypoxia at high altitude is incomplete and modification of existing analytical techniques may improve our knowledge considerably. We set out to use a novel simplified method of measuring in vivo capillary density during an expedition to high altitude using a CytoCam incident dark field imaging video-microscope. The simplified method of data capture involved recording one-second images of the mucosal surface of the inner lip to reveal data about microvasculature density in ten individuals. This was done on ascent to, and descent from, high altitude. Analysis was conducted offline by two independent investigators blinded to the participant identity, testing conditions and the imaging site. Additionally we monitored haemoglobin concentration and haematocrit data to see if we could support or refute mechanisms of altered density relating to vessel recruitment. Repeated sets of paired values were compared using Kruskall Wallis Analysis of Variance tests, whilst comparisons of values between sites was by related samples Wilcoxon Signed Rank Test. Correlation between different variables was performed using Spearman’s rank correlation coefficient, and concordance between analysing investigators using intra-class correlation coefficient. There was a significant increase in capillary density from London on ascent to high altitude; median capillaries per field of view area increased from 22.8 to 25.3 (p=0.021). There was a further increase in vessel density during the six weeks spent at altitude (25.3 to 32.5, p=0.017). Moreover, vessel density remained high on descent to Kathmandu (31.0 capillaries per field of view area), despite a significant decrease in haemoglobin concentration and haematocrit. Using a simplified technique, we have demonstrated an increase in capillary density on early and sustained exposure to hypobaric hypoxia at thigh altitude, and that this remains elevated on descent to normoxia. The technique is simple, reliable and reproducible

Global Variation of Nutritional Status in Children Undergoing Chronic Peritoneal Dialysis : A Longitudinal Study of the International Pediatric Peritoneal Dialysis Network

While children approaching end-stage kidney disease (ESKD) are considered at risk of uremic anorexia and underweight they are also exposed to the global obesity epidemic. We sought to investigate the variation of nutritional status in children undergoing chronic peritoneal dialysis (CPD) around the globe. The distribution and course of body mass index (BMI) standard deviation score over time was examined prospectively in 1001 children and adolescents from 35 countries starting CPD who were followed in the International Pediatric PD Network (IPPN) Registry. The overall prevalence of underweight, and overweight/obesity at start of CPD was 8.9% and 19.7%, respectively. Underweight was most prevalent in South and Southeast Asia (20%), Central Europe (16.7%) and Turkey (15.2%), whereas overweight and obesity were most common in the Middle East (40%) and the US (33%). BMI SDS at PD initiation was associated positively with current eGFR and gastrostomy feeding prior to PD start. Over the course of PD BMI SDS tended to increase on CPD in underweight and normal weight children, whereas it decreased in initially overweight patients. In infancy, mortality risk was amplified by obesity, whereas in older children mortality was markedly increased in association with underweight. Both underweight and overweight are prevalent in pediatric ESKD, with the prevalence varying across the globe. Late dialysis start is associated with underweight, while enteral feeding can lead to obesity. Nutritional abnormalities tend to attenuate with time on dialysis. Mortality risk appears increased with obesity in infants and with underweight in older children.Peer reviewe

The IDENTIFY study: the investigation and detection of urological neoplasia in patients referred with suspected urinary tract cancer - a multicentre observational study

Objective To evaluate the contemporary prevalence of urinary tract cancer (bladder cancer, upper tract urothelial cancer [UTUC] and renal cancer) in patients referred to secondary care with haematuria, adjusted for established patient risk markers and geographical variation. Patients and Methods This was an international multicentre prospective observational study. We included patients aged ≥16 years, referred to secondary care with suspected urinary tract cancer. Patients with a known or previous urological malignancy were excluded. We estimated the prevalence of bladder cancer, UTUC, renal cancer and prostate cancer; stratified by age, type of haematuria, sex, and smoking. We used a multivariable mixed-effects logistic regression to adjust cancer prevalence for age, type of haematuria, sex, smoking, hospitals, and countries. Results Of the 11 059 patients assessed for eligibility, 10 896 were included from 110 hospitals across 26 countries. The overall adjusted cancer prevalence (n = 2257) was 28.2% (95% confidence interval [CI] 22.3–34.1), bladder cancer (n = 1951) 24.7% (95% CI 19.1–30.2), UTUC (n = 128) 1.14% (95% CI 0.77–1.52), renal cancer (n = 107) 1.05% (95% CI 0.80–1.29), and prostate cancer (n = 124) 1.75% (95% CI 1.32–2.18). The odds ratios for patient risk markers in the model for all cancers were: age 1.04 (95% CI 1.03–1.05; P < 0.001), visible haematuria 3.47 (95% CI 2.90–4.15; P < 0.001), male sex 1.30 (95% CI 1.14–1.50; P < 0.001), and smoking 2.70 (95% CI 2.30–3.18; P < 0.001). Conclusions A better understanding of cancer prevalence across an international population is required to inform clinical guidelines. We are the first to report urinary tract cancer prevalence across an international population in patients referred to secondary care, adjusted for patient risk markers and geographical variation. Bladder cancer was the most prevalent disease. Visible haematuria was the strongest predictor for urinary tract cancer

New method for the fusion of complementary information from infrared and visual images for object detection

Visual and infrared cameras have complementary properties and using them together may increase the performance of object detection applications. Although the fusion of visual and infrared information results in a better recall rate than using only one of those domains, there is always a decrease in the precision rate whereas the infrared domain on its own always has higher precision. Thus, the fusion of these domains is meaningful only for a better recall rate, which means that more foreground pixels are detected correctly. This study presents a new computationally more efficient and simpler method for extracting the complementary information from both domains and fusing them to obtain better recall rates than those previously achieved. The method has been tested using a well-known database and a database created for the study and compared with earlier fusion methods

PREPARATION OF BLOCK-COPOLYMERS WITH MACROAZONITRILES AS THE INITIATOR

Block copolymers containing poly(ethylene oxide) or poly(propylene oxide) prepolymer segments and methyl methacrylate were prepared. A stepwise procedure was first employed to prepare macro-azocarbamates by capping hydroxy-terminated poly(ethylene oxide) or poly(propylene oxide) with 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate and subsequently reacting this intermediate with 4,4'-azobis(4-cyano-n-pentanol)**. The resulting polymeric azocarbamates were used as free-radical initiators for the polymerization of methyl methacrylate. Various modes of preparation and the properties of the copolymers are described. Formation of block copolymers is illustrated by several analyses and measurements of elastic modulus versus temperature

Synthesis and characterization of oligosalicylaldehyde-based epoxy resins

WOS: 000237134100012The synthesis of a new epoxy resin of oligosalicylaldehyde by the reaction with epichlorohydrin is reported. New resin's epoxy value and chlorine content were determined and found to be 25 % and 1 %, respectively. The characterization of the new resin was instrumented by FTIR, H-1 NMR, scanning electron microscopy, and thermal gravimetric analyses. TGA results showed that the cured epoxy resin has a good resistance to thermal decomposition. The mass losses of cured epoxy resin were found to be 5 %, 10 %, 50 % at 175 degrees C, 240 degrees C and 400 degrees C, respectively. On the curing procedure the resin was cured with polyethylenepolyamine at 25 degrees C for 8 h and 100 degrees C for 1.5 h. The FTIR spectrum of new epoxy resin gave the peak of oxirane ring a (nu) over bar = 918 cm(-1)

Excess volumetric properties of mixtures epichlorohydrine + acetone or chloroform at 291.15 and 296.15 K

The excess molar volumes and densities of mixtures containing epichlorohydrine, acetone, and chloroform were determined at different temperatures by the Redlich-Kister equation. Chemical interaction and physical forces are very important influences on the excess molar volume of (epichlorohydrine + acetone or chloroform) mixtures. In addition, the variations of excess molar volumes were expressed as function of temperature

Excess volumetric properties of mixtures (epichlorohydrine + toluene and epichlorohydrine + xylene) at 298.15, 308.15, 323.15, and 338.15 K

The densities and excess molar volumes of (epichlorohydrine + toluene and xylene) mixtures were determined at different temperatures. The graphs of excess molar volumes against mole fraction of mixtures show a negative and positive slope because of charge-transfer interaction and physical forces at 298.15, 308.15, 323.15, and 338.15 K, respectively

The synthesis, characterization and thermal stability of oligo-4-hydroxybenzaldehyde

WOS: 000189214900004Oligo-4-hydroxybenzaldehyde (OHBA) was synthesized from the oxidative polycondensation of 4-hydroxybenzaldehyde (HBA) with hydrogenperoxide (H2O2) in an aqueous alkaline medium at 85 degreesC. The product was characterized by H-1 NMR, FT-IR, UV-Vis and elemental analysis. The number average molecular weight, mass average molecular weight and polydispersity index values of OHBA were found to be 5171, 8625 g mol(-1) and 1.668, respectively. The thermal stability of the oligomer was measured by thermogravimetric analyses (TG) under an air atmosphere. TG analyses showed OHBA to be resistant to thermo-oxidative decomposition. The weight loss of OHBA was found to be 5, 50 and 89% at 171, 845 and 900 degreesC, respectively. According to TG analyses, the carboneous residues of the OHBA was 49.29% at 900 degreesC. (C) 2003 Elsevier Ltd. All rights reserved

Immobilization of invertase and glucose oxidase in conducting copolymers of thiophene functionalized poly(vinyl alcohol) with pyrrole

WOS: 000236451300007In this study, immobilizations of invertase and glucose oxidase were achieved in conducting thiophene functionalized copolymers of vinyl alcohol with thiophene side groups and pyrrole (PVATh/PPy) via electrochemical polymerization. The kinetic parameters, V-max (maximum reaction rate) and K-m (substrate affinity), of both free and immobilized enzymes were determined. The effect of supporting electrolytes, p-toluene sulfonic acid and sodium dodecyl sulfate, on the enzyme activity and film morphologies was examined. The optimum temperature, operational and storage stabilities of immobilized enzymes were determined. PVATh/PPy copolymer was found to exhibit significantly enhanced properties compared to pristine polypyrrole. (c) 2005 Elsevier B.V. All rights reserved