Theoretical study of the pH-dependent antioxidant properties of vitamin C

Molecules acting as antioxidants capable of scavenging reactive oxygen species (ROS) are of utmost importance in the living cell. Vitamin C is known to be one of these molecules. In this study we have analyzed the reactivity of vitamin C toward the $ \cdot OH $ and $ \cdot OOH $ ROS species, in all acidic, neutral and basic media. In order to do so, density functional theory (DFT) have been used. More concretely, the meta-GGA functional MPW1B95 have been used. Two reaction types have been studied in each case: addition to the ring atoms, and hydrogen/proton abstraction. Our results show that $ \cdot OH $ is the most reactive species, while $ \cdot OOH $ displays low reactivity. In all three media, vitamin C reactions with two hydroxyl radicals show a wide variety of possible products.     

Laparoscopic appendectomy to remove a metallic foreign body in a wild Bornean orangutan (Pongo pygmaeus) undergoing rehabilitation

A laparoscopic appendectomy was performed in a wild orangutan (Pongo pygmaeus) undergoing rehabilitation, for a metal nail found on radiographs, using 3‐mm instrumentation. Post‐operative healing was rapid and uneventful, with return to the forest within 10 days. This is the first report of minimally invasive surgery in a wild orangutan.     

Magnetoresistive immunosensor for the detection of Escherichia coli O157:H7 including a microfluidic network

A hand held device has been designed for the immunomagnetic detection and quantification of the pathogen Escherichia coli O157:H7 in food and clinical samples. In this work, a technology to manufacture a Lab on a Chip that integrates a 3D microfluidic network with a microfabricated biosensor has been developed. With this aim, the sensing film optimization, the design of the microfluidic circuitry, the development of the biological protocols involved in the measurements and, finally, the packaging needed to carry out the assays in a safe and straightforward way have been completed. The biosensor is designed to be capable to detect and quantify small magnetic field variations caused by the presence of superparamagnetic beads bound to the antigens previously immobilized on the sensor surface via an antibody-antigen reaction. The giant magnetoresistive multilayer structure implemented as sensing film consists of 20[Cu(5.10nm)/Co(2.47 nm)] with a magnetoresistance of 3.20% at 235Oe and a sensitivity up to 0.06 Omega/Oe between 150Oe and 230Oe. Silicon nitride has been selected as optimum sensor surface coating due to its suitability for antibody immobilization. In order to guide the biological samples towards the sensing area, a microfluidic network made of SU-8 photoresist has been included. Finally, a novel packaging design has been fabricated employing 3D stereolithographic techniques. The microchannels are connected to the outside using standard tubing. Hence, this packaging allows an easy replacement of the used devices.     

Simple and reliable multiplex PCR assay for detection of blaTEM,bla(SHV) and blaOXA-1 genes in Enterobacteriaceae

Third-generation cephalosporin resistance is often mediated by TEM- and SHV-type beta-lactamases in Enterobacteriaceae. TEM-type and OXA-1 enzymes are the major plasmid-borne beta-lactamases implicated in amoxicillin-clavulanic acid resistance in Escherichia coli isolates. We have developed a rapid and simple multiplex polymerase chain reaction (PCR) which discriminates bla(TEM), bla(SHV) and bla(OXA-1) genes by generating fragments of 516, 392 and 619 bp respectively. Multiplex PCR analysis of 51 amoxicillin-clavulanate resistant E. coli isolates detected bla(TEM) and bla(SHV) genes in 45 and two strains, respectively, and only one strain harboured a bla(OXA-1) gene. Twenty-three of the 40 cefotaxime-resistant Enterobacteriaceae isolates produced amplicons with a size compatible with the presence of bla(TEM) (13 strains), bla(SHV) (six strains) genes or the association of both genes (four strains). These results were verified by colony hybridisation. Therefore, multiplex PCR is a suitable tool for initial rapid screening of bla genes in Enterobacteriaceae.     

Social Support and Health in Diabetes Patients: An Observational Study in Six European Countries in an Era of Austerity

Introduction

Support from individual social networks, community organizations and neighborhoods is associated with better self-management and health outcomes. This international study examined the relative impact of different types of support on health and health-related behaviors in patients with type 2 diabetes.

Methods

Observational study (using interviews and questionnaires) in a sample of 1,692 type 2 diabetes patients with 5,433 connections from Bulgaria, Greece, Netherlands, Norway, Spain, and the United Kingdom. Outcomes were patient-reported health status (SF-12), physical exercise (RAPA), diet and smoking (SDCSCA). Random coefficient regression models were used to examine linkages with individual networks, community organizations, and neighborhood type (deprived rural, deprived urban, or affluent urban).

Results

Patients had a median of 3 support connections and 34.6% participated in community organizations. Controlled for patients’ age, sex, education, income and comorbidities, large emotional support networks were associated with decrease of non-smoking (OR = 0.87). Large practical support networks were associated with worse physical and mental health (B = -0.46 and -0.27 respectively) and less physical activity (OR = 0.90). Participation in community organizations was associated with better physical and mental health (B = 1.39 and 1.22, respectively) and, in patients with low income, with more physical activity (OR = 1.53).

Discussion

Participation in community organizations was most consistently related to better health status. Many diabetes patients have individual support networks, but this study did not provide evidence to increase their size as a public health strategy. The consistent association between participation in community organizations and health status provides a clear target for interventions and policies.     

GMR sensors: magnetoresistive behaviour optimization for biological detection by means of superparamagnetic nanoparticles

An immunomagnetic method for the selective and quantitative detection of biological species by means of a magnetoresistive biosensor and superparamagnetic particles has been optimized. In order to achieve this, a giant magnetoresistive [Co (5.10nm)/Cu (2.47 nm)](20) multilayer structure has been chosen as the sensitive material, showing a magnetoresistance of 3.60% at 215 Oe and a sensitivity up to 0.19 Ω/Oe between 145 Oe and 350 Oe. The outward gold surface of the sensor is biofunctionalized with a Self-Assembled Monolayer (SAM). In addition, three different types of magnetic labels have been tested. 2 μm diameter magnetic carriers (7.68 pg ferrite/particle) have shown the best response and they have induced a shift in the magnetoresistive hysteresis loops up to 9% at 175 Oe.     

Impact of tapering and proactive recovery on young elite rugby union players’ repeated high intensity effort ability

To assess the effects of a taper combined with proactive recovery on the repeated high intensity effort (RHIE) of elite rugby union players, and the possible interaction of pre-taper fatigue and sleep. Eighteen players performed a 3-week intensive training block followed by a 7-day exponential taper combined with a multicomponent recovery strategy. Following the intervention, players were divided into 3 groups (Normal Training: NT, Acute Fatigue: AF or Functional Overreaching: F-OR) based on their readiness to perform prior to the taper. Total sprint time [TST], percentage decrement [%D] and the number of sprints ≥90% of the best [N90] were analyzed to assess performance during a RHIE test. Subjective sleep quality was assessed through the Pittsburg Sleep Quality Index (PSQI) and the Epworth Sleepiness Scale (ESS). No improvement in TST was reported in either NT or F-OR after the taper, whereas AF tended to improve (-1.58 ± 1.95%; p > 0.05; g = -0.20). F-OR players reported baseline PSQI and ESS indicative of sleep disturbance (6.2 ± 2.2 and 10.6 ± 5.4, respectively). AF displayed a small impairment in PSQI during intensive training (11.5 ± 80.6%; p > 0.05; g = 0.20), which was reversed following the taper (-34.6 ± 62.1%; p > 0.05; g = -0.73). Pre-taper fatigue precluded the expected performance benefits of the combined taper and recovery intervention, likely associated with a lack of strictly controlled intensive training block. Poor sleep quality before the intensive training period appeared to predispose the players to developing functional overreaching.     

Scientific approach to the 1-h cycling world record: a case study.

The purpose of this study was to describe the physiological and aerodynamic characteristics and the preparation for a successful attempt to break the 1-h cycling world record. An elite professional road cyclist (30 yr, 188 cm, 81 kg) performed an incremental laboratory test to assess maximal power output (W(max)) and power output (W(OBLA)), estimated speed (V(OBLA)), and heart rate (HR(OBLA)) at the onset of blood lactate accumulation (OBLA). He also completed an incremental velodrome (cycling track) test (VT1), during which V(OBLAVT1) and HR(OBLAVT1) were measured and W(OBLAVT1) was estimated. W(max) was 572 W, W(OBLA) 505 W, V(OBLA) 52.88 km/h, and HR(OBLA) 183 beats/min. V(OBLAVT1), HR(OBLAVT1), and W(OBLAVT1) were 52.7 km/h, 180 beats/min, and 500.6 W, respectively. Drag coefficient and shape coefficient, measured in a wind tunnel, were 0. 244 and 0.65 m(2), respectively. The cyclist set a world record of 53,040 m, with an estimated average power output of 509.5 W. Based on direct laboratory data of the power vs. oxygen uptake relationship for this cyclist, this is slightly higher than the 497. 25 W corresponding to his oxygen uptake at OBLA (5.65 l/min). In conclusion, 1) the 1-h cycling world record is the result of the interaction between physiological and aerodynamic characteristics; and 2) performance in this event can be predicted using mathematical models that integrate the principal performance-determining variables.     

Carbohydrate loading failed to improve 100-km cycling performance in a placebo-controlled trial.

We evaluated the effect of carbohydrate (CHO) loading on cycling performance that was designed to be similar to the demands of competitive road racing. Seven well-trained cyclists performed two 100-km time trials (TTs) on separate occasions, 3 days after either a CHO-loading (9 g CHO. kg body mass(-1). day(-1)) or placebo-controlled moderate-CHO diet (6 g CHO. kg body mass(-1). day(-1)). A CHO breakfast (2 g CHO/kg body mass) was consumed 2 h before each TT, and a CHO drink (1 g CHO. kg(.)body mass(-1). h(-1)) was consumed during the TTs to optimize CHO availability. The 100-km TT was interspersed with four 4-km and five 1-km sprints. CHO loading significantly increased muscle glycogen concentrations (572 +/- 107 vs. 485 +/- 128 mmol/kg dry wt for CHO loading and placebo, respectively; P < 0.05). Total muscle glycogen utilization did not differ between trials, nor did time to complete the TTs (147.5 +/- 10.0 and 149.1 +/- 11.0 min; P = 0.4) or the mean power output during the TTs (259 +/- 40 and 253 +/- 40 W, P = 0.4). This placebo-controlled study shows that CHO loading did not improve performance of a 100-km cycling TT during which CHO was consumed. By preventing any fall in blood glucose concentration, CHO ingestion during exercise may offset any detrimental effects on performance of lower preexercise muscle and liver glycogen concentrations. Alternatively, part of the reported benefit of CHO loading on subsequent athletic performance could have resulted from a placebo effect.