mTOR Signaling in the Inner Ear as Potential Target to Treat Hearing Loss

Hearing loss affects many people worldwide and occurs often as a result of age, ototoxic drugs and/or excessive noise exposure. With a growing number of elderly people, the number of people suffering from hearing loss will also increase in the future. Despite the high number of affected people, for most patients there is no curative therapy for hearing loss and hearing aids or cochlea implants remain the only option. Important treatment approaches for hearing loss include the development of regenerative therapies or the inhibition of cell death/promotion of cell survival pathways. The mammalian target of rapamycin (mTOR) pathway is a central regulator of cell growth, is involved in cell survival, and has been shown to be implicated in many age-related diseases. In the inner ear, mTOR signaling has also started to gain attention recently. In this review, we will emphasize recent discoveries of mTOR signaling in the inner ear and discuss implications for possible treatments for hearing restoration.     

Graphene-Based Sensors for the Detection of Bioactive Compounds: A Review

Over the last years, different nanomaterials have been investigated to design highly selective and sensitive sensors, reaching nano/picomolar concentrations of biomolecules, which is crucial for medical sciences and the healthcare industry in order to assess physiological and metabolic parameters. The discovery of graphene (G) has unexpectedly impulsed research on developing cost-effective electrode materials owed to its unique physical and chemical properties, including high specific surface area, elevated carrier mobility, exceptional electrical and thermal conductivity, strong stiffness and strength combined with flexibility and optical transparency. G and its derivatives, including graphene oxide (GO) and reduced graphene oxide (rGO), are becoming an important class of nanomaterials in the area of optical and electrochemical sensors. The presence of oxygenated functional groups makes GO nanosheets amphiphilic, facilitating chemical functionalization. G-based nanomaterials can be easily combined with different types of inorganic nanoparticles, including metals and metal oxides, quantum dots, organic polymers, and biomolecules, to yield a wide range of nanocomposites with enhanced sensitivity for sensor applications. This review provides an overview of recent research on G-based nanocomposites for the detection of bioactive compounds, providing insights on the unique advantages offered by G and its derivatives. Their synthesis process, functionalization routes, and main properties are summarized, and the main challenges are also discussed. The antioxidants selected for this review are melatonin, gallic acid, tannic acid, resveratrol, oleuropein, hydroxytyrosol, tocopherol, ascorbic acid, and curcumin. They were chosen owed to their beneficial properties for human health, including antibiotic, antiviral, cardiovascular protector, anticancer, anti-inflammatory, cytoprotective, neuroprotective, antiageing, antidegenerative, and antiallergic capacity. The sensitivity and selectivity of G-based electrochemical and fluorescent sensors are also examined. Finally, the future outlook for the development of G-based sensors for this type of biocompounds is outlined.     

Catalytic electro-oxidation of hydrazine on phthalocyanines deposited on graphite electrodes

The catalytic properties phthalocyanines of Fe, Co, Ni and Cu for the electro-oxidation of hydrazine have been examined. The metal chelates were deposited on ordinary pyrolytic graphite electrodes and their redox properties were studied by cyclic voltammetry. The catalytic activity was found to decrease as follows: FePc > CoPc > CuPc ～ NiPc > graphite.The kinetics of the process with Fe-Pc and Co-Pc were examined. Tafel slopes of 40 mV for Fe-Pc, and of 60 m V for Co-Pc were obtained. The chemical order in N₂H₄ is 1 both complexes. The order in OH^? is 2 for Fe-Pc and 1 for Co-Pc. With Fe-Pc, the transfer of a second electron seems to be rate determining. With Co-Pc, a slow chemical step preceded by a fast one-electron transfer seems to operate.     

Pouvons-nous diminuer ou prevenir 1'apparition des reactions de stress post-traumatiques? Analyse critique de 1'efficacite du debriefing.

The goal of this article is to analyze the efficacy of debriefing techniques to prevent psychological consequences following traumatic events. The type of traumatic incident, the method, the model of debriefing, the types of measures, and the results of the interventions are examined in the analysis of fifteen studies. Even though, victims in general appreciate debriefing, results from controlled studies seem to indicate that debriefing does not reduce or prevent post-traumatic stress reactions. Implications of these findings and hints for future interventions and research are discussed. It seems of great importance to promote more complete interventions that take into account the different characteristics of the traumatic events and the specific needs of the victims. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Embedded proteins and sacrificial bonds provide the strong adhesive properties of gastroliths

The adhesive properties of gastroliths from a freshwater crayfish (Cherax quadricarinatus) were quantified by colloidal probe atomic force microscopy (AFM) between heavily demineralized gastrolith microparticles and gastrolith substrates of different composition. Combined AFM and transmission electron microscopy studies demonstrated that the sequential detachment and large adhesion energies that characterise the adhesive behaviour of a native gastrolith substrate are dominated by sacrificial bonds between chitin fibres and between chitin fibres and CaCO(3). The sacrificial bonds were shown to be strongly related to the gastrolith proteins and when the majority of these proteins were removed by ethylenediaminetetraacetic acid (EDTA), the sequential detachment disappeared and the adhesive energy was reduced by more than two orders of magnitude.     

Detection of microsporidia in drinking water, wastewater and recreational rivers

Diarrhea is the main health problem caused by human-related microsporidia, and waterborne transmission is one of the main risk factors for intestinal diseases. Recent studies suggest the involvement of water in the epidemiology of human microsporidiosis. However, studies related to the presence of microsporidia in different types of waters from countries where human microsporidiosis has been described are still scarce. Thirty-eight water samples from 8 drinking water treatment plants (DWTPs), 8 wastewater treatment plants (WWTPs) and 6 recreational river areas (RRAs) from Galicia (NW Spain) have been analyzed. One hundred liters of water from DWTPs and 50 L of water from WWTPs and RRAs were filtered to recover parasites, using the IDEXX Filta-Max® system.Microsporidian spores were identified by Weber’s stain and positive samples were analyzed by PCR, using specific primers for Enterocytozoon bieneusi, Encephalitozoon intestinalis, Encephalitozoon cuniculi, and Encephalitozoon hellem. Microsporidia spores were identified by staining protocols in eight samples (21.0%): 2 from DWTPs, 5 from WWTPs, and 1 from an RRA. In the RRA sample, the microsporidia were identified as E. intestinalis.To the best of our knowledge, this is the first report of human-pathogenic microsporidia in water samples from DWTPs, WWTPs and RRAs in Spain. These observations add further evidence to support that new and appropriate control and regulations for drinking, wastewater, and recreational waters should be established to avoid health risks from this pathogen.     

Solid-phase extraction of amphiphiles based on mixed hemimicelle/admicelle formation: application to the concentration of benzalkonium surfactants in sewage and river water

The capability of surfactant-coated mineral oxides to aid the solid-phase extraction (SPE) of amphiphiles based on the formation of mixed hemimicelles/admicelles was investigated. The approach is illustrated by studying the adsolubilization of benzalkonium homologue (C(12), C(14), C(16)) surfactants (BAS) on sodium dodecyl sulfate (SDS)-coated alumina. These oppositely charged surfactants form mixed aggregates on alumina causing retention of BAS by strong hydrophobic and ionic interactions. The recovery of BAS was found quantitative and independent of the alkyl chain length under a wide range of experimental conditions (3-200 mg of SDS/g of alumina; pH 2-11; sample flow rate 3-20 mL/min, and sample loading volume 0.025-1 L). Anionic and nonionic surfactants and electrolytes did not interfere to the levels found in raw sewage. Combination of BAS adsolubilization-based SPE with liquid chromatography/electrospray ionization in positive ion mode/ion trap mass spectrometry permitted the quantification of BAS with detection limits of 4 ng/L and their identification by isolation and subsequent fragmentation in the ion trap. The approach developed was applied to the determination of BAS in raw and treated sewage and river samples. The concentrations of benzalkonium surfactants found ranged between 0.1 and 49 microg/L.     

Enhancement of 4-chlorophenol biodegradation using glucose

Toxic, xenobiotic chemicals present challenging problems for the environment since they are normally resistant to biodegradation. Sometimes it is possible to induce biodegradation activity by the use of growth cosubstrates. In this study, pure solutions and binary mixtures of glucose, phenol and 4-chlorophenol have been metabolized in batch cultures by a pure strain of Pseudomonas putida. Following a lag period during which slow growth and low production of biomass occurred, phenol was metabolized according to the Monod model. Glucose was also metabolized according to the Monod model but exponential growth commenced immediately after inoculation with no noticeable lag phase. Biokinetic behavior for growth on a mixture of phenol and glucose paralleled the behavior on individual substrates with simultaneous consumption of both substrates. 4-chlorophenol was not consumed as a sole substrate by Pseudomonas putida but was consumed as a cometabolite with either glucose or phenol acting as the primary growth cosubstrate. Surprisingly, glucose was found to be the superior growth cosubstrate, suggesting that inexpensive sugars can be used to enhance the biodegradation of chlorophenol-contaminated sites. Glucose and the excreted metabolic products of the biodegradation process, including a bright yellow pigment, demonstrated negligible toxicity towards Artemia salina, unlike the phenol and 4-chlorophenol substrates. Electronic Publication     

Using maximal spanning trees and word similarity to generate hierarchical clusters of non-redundant RSS news articles

RSS news articles that are either partially or completely duplicated in content are easily found on the Internet these days, which require Web users to sort through the articles to identify non-redundant information. This manual-filtering process is time-consuming and tedious. In this paper, we present a new filtering and clustering approach, called FICUS, which starts with identifying and eliminating redundant RSS news articles using a fuzzy set information retrieval approach and then clusters the remaining non-redundant RSS news articles according to their degrees of resemblance. FICUS uses a tree hierarchy to organize clusters of RSS news articles. The contents of the respective clusters are captured by the representative keywords from RSS news articles in the clusters so that searching and retrieval of similar RSS news articles is fast and efficient. FICUS is simple, since it uses the pre-defined word-correlation factors to determine related (words in) RSS news articles and filter redundant ones, and is supported by well-known and yet simple mathematical models, such as the standard deviation, vector space model, and probability theory, to generate clusters of non-redundant RSS news articles. Experiments performed on (test sets of) RSS news articles on various topics, which were downloaded from different online sources, verify the accuracy of FICUS on eliminating redundant RSS news articles, clustering similar RSS news articles together, and segregating different RSS news articles in terms of their?contents. In addition, further empirical studies show that FICUS outperforms well-known approaches adopted for clustering RSS news articles.