Nitrogen-doped carbon dots embedded in a SiO 2 monolith for solid-state fluorescent detection of Cu 2+ ions

Abstract

We describe the simple fabrication of SiO₂ sol-gel monoliths embedding highly luminescent carbon nanodots (CDs) sensitive to metal ions. The pristine CDs we synthesize display an intense dual emission consisting in two fluorescence bands in the green and violet region, and we demonstrate that this photoluminescence is substantially unchanged when the dots are incorporated in the SiO₂ matrix. The emission of these CDs is quenched by interactions with Cu²⁺ ions, which can be used to detect these ions with a detection limit of 1 μM. The chromophores remain accessible to diffusing Cu²⁺ ions even after embedding CDs in the sol-gel monolith, where their detection capabilities are preserved. Such a result provides the proof-of-principle of a new sensing scheme, where CDs are exploited as active sensing centers of metal transition ions within a solid-state device. The different interaction mechanisms of CDs with copper, in liquid and solid phase, are analyzed in detail and discussed in terms of different accessibility of their chromophores when the dots are incorporated in the SiO₂ matrix.

http://ift.tt/2rJ4jTc

Airway Management in Combat Trauma

Abstract

Purpose of Review

Airway compromise remains a leading cause of death in battlefield trauma. The purpose of this review is to examine the impact of airway compromise on survival in the combat trauma population and assess the challenges in providing effective airway management in the combat environment when contrasted with the civilian peacetime environment.

Recent Findings

Management approaches in the civilian trauma setting are not necessarily applicable in the combat environment due to differences in injury patterns and extent of prehospital airway operator training. Although outcomes with airway management in both combat and civilian trauma environments are improved when more skilled providers are involved, this is not always a feasible option in the combat environment.

Summary

The prehospital setting represents the area of greatest difference in planning and practice between the civilian and combat trauma systems. Further research is necessary to improve training strategies and equipment used in combat airway management.

http://ift.tt/2rY6VAu

The Cathinones MDPV and α-PVP Elicit Different Behavioral and Molecular Effects Following Acute Exposure

Abstract

Since the mid-to-late 2000s, synthetic cathinones have gained popularity among drug users due to their psychostimulant effects greater than those produced by cocaine and amphetamine. Among them, 3,4-methylenedioxypyrovalerone (MDPV) and 1-phenyl-2-(pyrrolidin-1-yl)pentan-1-one (α-PVP) are ones of the most popular cathinones available in the clandestine market as "bath salts" or "fertilizers." Pre-clinical studies indicate that MDPV and α-PVP induced psychomotor stimulation, affected thermoregulation, and promoted reinforcing properties in rodents. However, a direct comparative analysis on the effects caused by MDPV and α-PVP on the behavior and neuronal activation in rodents is still lacking. Behavioral analyses revealed that both MDPV and α-PVP affect spontaneous and stimulated motor responses. In particular, MDPV showed a greater psychomotor effect than α-PVP in line with its higher potency in blocking the dopamine transporter (DAT). Notably, MDPV was found to be more effective than α-PVP in facilitating spontaneous locomotion and it displayed a biphasic effect in contrast to the monophasically stimulated locomotion induced by α-PVP. In addition to the behavioral results, we also found a different modulation of immediate early genes (IEGs) such as Arc/Arg3.1 and c-Fos in the frontal lobe, striatum, and hippocampus, indicating that these drugs do impact brain homeostasis with changes in neuronal activity that depend on the drug, the brain area analyzed, and the timing after the injection. These results provide the first discrimination between MDPV and α-PVP based on behavioral and molecular data that may contribute to explain, at least in part, their toxicity.

http://ift.tt/2rXvEFr

Bubble removal with the use of a vacuum pressure generated by a converging-diverging nozzle

Abstract

Bubbles are an intrinsic problem in microfluidic devices and they can appear during the initial filling of the device or during operation. This report presents a generalizable technique to extract bubbles from microfluidic networks using an adjacent microfluidic negative pressure network over the entire microfluidic channel network design. We implement this technique by superimposing a network of parallel microchannels with a vacuum microfluidic channel and characterize the bubble extraction rates as a function of negative pressure applied. In addition, we generate negative pressure via a converging-diverging (CD) nozzle, which only requires inlet gas pressure to operate. Air bubbles generated during the initial liquid filling of the microfluidic network are removed within seconds and their volume extraction rate is calculated. This miniaturized vacuum source can achieve a vacuum pressure of 7.23 psi which corresponds to a bubble extraction rate of 9.84 pL/s, in the microfluidic channels we characterized. Finally, as proof of concept it is shown that the bubble removal system enables bubble removal on difficult to fill microfluidic channels such as circular or triangular shaped channels. This method can be easily integrated into many microfluidic experimental protocols.

http://ift.tt/2rIYODZ

The relationship between circulating adiponectin, leptin and vaspin with bone mineral density (BMD), arterial calcification and stiffness: a cross-sectional study in post-menopausal women

Abstract

Objective

To explore the relationship between circulating adiponectin, leptin and vaspin with bone mineral density (BMD), arterial stiffness and vascular calcification in post-menopausal women. We hypothesised that adipokines produced by adipose tissue may be mediators of bone and cardiovascular disease (CVD) and explain, in part, the observed association between osteoporosis and CVD.

Design

We studied 386 ambulant community dwelling postmenopausal women aged (mean [SD] 61 [6.4] years). BMD at the lumbar spine, femoral neck (FN), and total hip (TH), body composition; fat mass (FM) and lean mass (LM) as well as abdominal aortic calcification (AAC) were determined by dual energy X-ray absorptiometry. Pulse wave velocity (PWV) and augmentation index, markers of arterial stiffness were measured. Fasting adiponectin, leptin and vaspin were quantified in serum.

Results

A positive independent association was observed between vaspin and BMD at the FN (p = 0.009), TH (p = 0.037) in the whole study population adjusted for confounders including age, FM, LM and lifestyle variables. Using the same model, a negative association was seen between adiponectin and BMD at the FN in women with osteoporosis (p = 0.043). Serum adiponectin was significantly higher in women with fractures (20.8 [9.3] µg/ml compared to those without (18.5 [8.6] µg/ml, p = 0.018) and associated with a significant increased risk of fracture (HR 1.032, 95% CI 1.003–1.063, p = 0.032). Leptin was not associated with BMD or fracture risk after adjustment. Adiponectin was independently associated with AAC (p = 0.007) and significantly higher in women with AAC scores > 1; (19.2[9.2]) compared to those with no or low AAC scores (<1); 16.8 [8.0], p = 0.018). In adjusted analyses, PWV velocity was positively associated with circulating vaspin (p = 0.039) and AI was negatively associated with serum leptin (p = 0.002).

Conclusion

Adiponectin, leptin, vaspin are related to markers of bone and vascular health and may contribute to the observed association between osteoporosis and CVD.

http://ift.tt/2sxpCK6

Mesenchymal stem cell therapy for acute and chronic pancreatitis

Abstract

Mesenchymal stem cells (MSCs) have attracted attention as a cell source for regenerative medicine. In particular, MSCs have an anti-inflammatory effect by secreting several kinds of bioactive molecules. MSC therapy is now being applied to various gastrointestinal diseases, such as graft-versus-host disease, inflammatory bowel disease, and liver cirrhosis. Therefore, MSC therapy has the potential to be a novel treatment for acute and chronic pancreatitis by suppressing inflammation. Several studies have investigated the effect of MSC therapy on acute and chronic pancreatitis, but the underlying mechanisms remain unknown. In this review, we summarize the present status of MSC therapy for acute and chronic pancreatitis.

http://ift.tt/2tAFM3O

Recommandations européennes sur la prise en charge endoscopique de l’endobrachyoesophage

http://ift.tt/2sxiddS