Selective and sensitive colorimetric detection of endocrine disrupter fungicide carbendazim through secnidazole capped silver nanoparticles

Pesticides and fungicides are extremely useful to hinder the attacks of pests and fungi to secure crops, vegetables, fruits and other plants but due to their endocrine disrupting and carcinogenic risks in humans and animals through their continued addition in water resources they are extremely important to monitor carefully. In this investigation we synthesized silver nanoparticles (AgNPs) via the reducing action of sodium borohydride in the presence of secnidazole (SEC) as capping agent under various optimized parameters such as the concentration of NaBH4, silver nitrate (AgNO3), SEC and pH. These SEC-AgNPs were characterized through various techniques including ultra-violet visible (UV-Vis) spectroscopy, Fourier transform infra-red (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), dynamic light scattering (DLS) and zeta-potential analysis (ZPA) in order to investigate their diverse properties. As prepared SEC-AgNPs were proved as extremely sensitive for trace level sensing of fungicide carbendazim (CARB) in the range of 0.5-22 µM with limit of detection (LOD) equal to 0.021 µM and R2 value of 0.9964. SEC-AgNPs were tested for CARB sensing under the presence of several pesticides with negligible interference thus verifying its exclusive selectivity for the targeted analyte. This SEC-AgNPs was further applied to find out the concentration of CARB in real samples of tap water and human blood plasma with reference to standard addition method.

Simpler and highly sensitive enzyme-free sensing of urea via NiO nanostructures modified electrode

In this study, NiO nanostructures were synthesized via a hydrothermal process using ascorbic acid as doping agent in the presence of ammonia.

Impact of a GP-led walk-in centre on NHS emergency departments

OBJECTIVE

To determine the impact of the GP-led walk-in centre (WIC) in Sheffield (England) on the demand for emergency department (ED) care.

METHODS

A survey of patients visiting the Sheffield GP WIC was conducted over 3 weeks during September and October 2011. A short, postvisit questionnaire was also sent to those who agreed to determine if the patient had used another NHS service for the same problem. Routine data were obtained from the adult and children's EDs and minor injuries unit in Sheffield, 1 year before and 1 year after the opening of the GP WIC. A linear model of the number of minor daytime attendances (GP type) per month was used to estimate the impact of opening the GP WIC, after controlling for seasonal variation and a linear time trend.

RESULTS

A total of 529 patients responded to the survey (response rate 51%). Based on their self-reported intentions, 64 of these patients (53 adults and 11 children) were diverted from going to ED in the 3-week survey period as a result of the establishment of the GP WIC. From this we would have expected around a 26% monthly reduction in GP-type attendances at adult ED, and 7% reduction at children's ED. However, routine data only showed an 8% (95% CI 1% to 16%) reduction at the adult ED. Reductions in GP-type attendances at the children's ED and the minor injury unit at the time of the opening of the GP WIC were also found, but were not statistically significant. The estimated impact on children's ED was a 14% reduction (95% CI -38% to 8%), and for minor injuries unit (MIU) a 4% reduction (95% CI -18 to 9%).

CONCLUSIONS

There was a statistically significant reduction in GP-type daytime attendances at the adult ED after the opening of the GP WIC. Since this reduction was not mirrored in changes in night-time attendances (when the GP WIC was closed), and our survey responses suggested some people were diverted from going to the ED, it is possible that the opening of the GP WIC caused this reduction.

Preoperative fasting time in children

The aim of preoperative fasting is to prevent regurgitation and pulmonary aspiration while limiting potential problems of thirst, dehydration and hypoglycaemia. The American Society of Anaesthesiologists (ASA) has suggested guidelines for preoperative fasting for children undergoing elective surgery. We did a postal survey to determine the current practice regarding these guidelines amongst all specialist registrars in anaesthesia in Ireland. A questionnaire was sent to all specialist registrars in anaesthesia (90 in total), 60 (67%) were returned and analysed. The question asked was how long children should be kept fasting before elective surgery. The results of our survey suggest that most of the respondents are following the ASA guidelines for clear fluids and solids however there were differing opinion regarding the duration of fasting for formula milk and breast milk. In conclusion, we would recommend greater awareness and collaboration between anaesthetists, nurses and surgeons to ensure that fasting instructions are consistent with the ASA guidelines and that patient and their parents understand these directives as well.

When are reflux episodes symptomatic?

Careful scrutiny of pH recordings and symptom diaries in patients having 24-hour pH-metry reveals that most reflux episodes are asymptomatic. Although this observation is well known and long recognized, the explanation for why one reflux episode leads to symptoms and others do not is incompletely understood. Forty-four patients with chronic typical gastroesophageal reflux disease (GERD) symptoms referred for ambulatory pH testing were studied. Antisecretory medication was stopped 2 weeks prior to the study. Two meals were taken during the study; one standardized (hamburger, fries, milk-shake) and one at the patient's discretion. A system onset marker noted the type, beginning and end of symptoms (heartburn, regurgitation, chest pain). Age, sex, upright/supine position, nadir pH, time pH < 4, and relationship to meals were compared for symptomatic/asymptomatic reflux episodes. An acid reflux event was defined as a drop in pH < 4 lasting > 5 seconds. The pH catheter detected 1464 reflux episodes. Only 93 (6.3%) were symptomatic. Forty-six of the 93 (49.4%) were associated with heartburn, 38 (40.9%) with regurgitation, and nine (9.7%) with chest pain. Nadir pH was significantly lower in symptomatic episodes. Nearly 50% of symptomatic reflux episodes occurred after meals, especially after non-standardized compared to standardized meal. Symptomatic episodes tended to be longer in duration and to occur in the supine position, while age/sex made no difference. Six percent of the reflux episodes were temporally associated with typical GERD symptoms. This association seems to be influenced by the acidity of the refluxate. Nearly half of the symptomatic reflux episodes occurred after eating.

Interactions of sodium pentobarbital with D-glucose and L-sorbose transport in human red cells

Pentobarbital acts as a mixed inhibitor of net D-glucose exit, as monitored photometrically from human red cells. At 30 degrees C the Ki of pentobarbital for inhibition of Vmax of zero-trans net glucose exit is 2.16+/-0.14 mM; the affinity of the external site of the transporter for D-glucose is also reduced to 50% of control by 1. 66+/-0.06 mM pentobarbital. Pentobarbital reduces the temperature coefficient of D-glucose binding to the external site. Pentobarbital (4 mM) reduces the enthalpy of D-glucose interaction from 49.3+/-9.6 to 16.24+/-5.50 kJ/mol (P<0.05). Pentobarbital (8 mM) increases the activation energy of glucose exit from control 54.7+/-2.5 kJ/mol to 114+/-13 kJ/mol (P<0.01). Pentobarbital reduces the rate of L-sorbose exit from human red cells, in the temperature range 45 degrees C-30 degrees C (P<0.001). On cooling from 45 degrees C to 30 degrees C, in the presence of pentobarbital (4 mM), the Ki (sorbose, glucose) decreases from 30.6+/-7.8 mM to 14+/-1.9 mM; whereas in control cells, Ki (sorbose, glucose) increases from 6.8+/-1.3 mM at 45 degrees C to 23.4+/-4.5 mM at 30 degrees C (P<0.002). Thus, the glucose inhibition of sorbose exit is changed from an endothermic process (enthalpy change=+60.6+/-14.7 kJ/mol) to an exothermic process (enthalpy change=-43+/-6.2 7 kJ/mol) by pentobarbital (4 mM) (P<0.005). These findings indicate that pentobarbital acts by preventing glucose-induced conformational changes in glucose transporters by binding to 'non-catalytic' sites in the transporter.