Efficient Anodically Grown WO3 for Photoelectrochemical Water Splitting

Abstract The potentiostatic anodization of metallic tungsten has been investigated in different solvent/electrolyte compositions with the aim of improving the photoelectrochemical performances of the tungsten oxide layer. Among the explored electrolytes, the anodization in the NMF/H2O/NH4F solvent mixture was found to produce the most efficient WO3 photoanodes, which, combining spectral sensitivity, high electrochemically active surface and improved charge transfer kinetics, outperform, under simulated solar illumination, most of the reported nanocrystalline substrates produced by anodization in aqueous electrolytes and by sol gel methods. While the preparation of the photoelectrodes is a slow process at room temperature (20 °C), it could be greatly accelerated (x 10) by carrying out the anodization at 40-50 °C, thus proving to be a fast and convenient approach to the production of high performing WO3 photoactive substrates directly connected to a metal electron collector

Brain Abcess due to Cladophialophora bantiana: first case in Portugal

Clinical case reporting a brain abscess caused by Cladophialophora bantiana in an male patient with 56 years old. This is a rare case of a brain abscess caused by this species. Few cases have been reported in the literature world-wide, being this one the first reported in Portugal. The fungal isoltate was identified by morphological and molecular methods. After 16 months of the first brain abscess excision and after 5 months under therapy with voriconazol, the patient improved clinical and imagiologicaly, maintaining only minimal neurological deficits

Estudo Viriato: Actualização de dados de susceptibilidade aos antimicrobianos de bactérias responsáveis por infecções respiratórias adquiridas na comunidade em Portugal em 2003 e 2004

O Estudo Viriato é um estudo nacional, prospectivo e multicêntrico, de vigilância da susceptibilidade aos antimicrobianos de bactérias frequentemente responsáveis por infecções do aparelho respiratório adquiridas na comunidade.Nos anos de 2003 e 2004 participaram 29 laboratórios de todo o país. Isolaram-se 2945 microrganismos que foram estudados num laboratório coordenador. Das 513 estirpes de Streptococcus pyogenes de doentes com amigdalo-faringite aguda, todas eram susceptíveis à penicilina e outros antibióticos beta-lactâmicos, mas 18,9% eram resistentes à eritromicina, claritromicina e azitromicina. Nas estirpes resistentes foi mais frequente o fenótipo M (67,0%) que confere resistência à eritromicina (CIM90=16 mg/L), claritromicina e azitromicina, mas susceptibilidade à clindamicina (CIM90=0,094 mg/L). De doentes com infecção do aparelho respiratório inferior estudaram-se 1300 estirpes de Streptococcus pneumoniae (pneumococos), 829 de Haemophilus influenzae e 303 de Moraxella catarrhalis. Em S. pneumoniae, 18,4% das estirpes eram resistentes à penicilina (3,5% com resistência elevada), 7,1% à cefuroxima, 0,5% à amoxicilina, 0,5% à amoxicilina/clavulanato, 18,8% à eritromicina, claritromicina e azitromicina, 14,5 % à tetraciclina, 16,5% ao cotrimoxazol e 0,4% à levofloxacina. Nas estirpes resistentes aos macrólidos, dominou o fenótipo MLSB (83,7%), caracterizado por resistência elevada (CIM90>256 mg/L) à eritromicina, claritromicina, azitromicina e clindamicina. Produziam beta- -lactamase 10,0% de H. influenzae e 96,4% de M. catarrhalis. Em H. influenzae demonstrou-se 5,5% de resistência à claritromicina e 13,4% ao cotrimoxazol. A quase totalidade das estirpes era susceptível à amoxicilina / clavulanato, cefuroxima, azitromicina, tetraciclina e ciprofloxacina. Em M. catarrhalis a resistência ao co-trimoxazol foi de 27,1% e à tetraciclina de 1,0%. Todas as estirpes eram susceptíveis à amoxicilina / clavulanato, cefuroxima, claritromicina, azitromicina e ciprofloxacina. De entre o conjunto de antibióticos ensaiado, a penicilina continua a ser o mais activocontra S. pyogenes e a amoxicilina / clavulanato e as quinolonas os mais activos simultaneamente contra S. pneumoniae, H. influenzae e M. catarrhalis

Susceptibility Patterns of Staphylococcus Aureus Biofilms in Diabetic Foot Infections

BACKGROUND: Foot infections are a major cause of morbidity in people with diabetes and the most common cause of diabetes-related hospitalization and lower extremity amputation. Staphylococcus aureus is by far the most frequent species isolated from these infections. In particular, methicillin-resistant S. aureus (MRSA) has emerged as a major clinical and epidemiological problem in hospitals. MRSA strains have the ability to be resistant to most β-lactam antibiotics, but also to a wide range of other antimicrobials, making infections difficult to manage and very costly to treat. To date, there are two fifth-generation cephalosporins generally efficacious against MRSA, ceftaroline and ceftobripole, sharing a similar spectrum. Biofilm formation is one of the most important virulence traits of S. aureus. Biofilm growth plays an important role during infection by providing defence against several antagonistic mechanisms. In this study, we analysed the antimicrobial susceptibility patterns of biofilm-producing S. aureus strains isolated from diabetic foot infections. The antibiotic minimum inhibitory concentration (MIC) was determined for ten antimicrobial compounds, along with the minimum biofilm inhibitory concentration (MBIC) and minimum biofilm eradication concentration (MBEC), followed by PCR identification of genetic determinants of biofilm production and antimicrobial resistance. RESULTS: Results demonstrate that very high concentrations of the most used antibiotics in treating diabetic foot infections (DFI) are required to inhibit S. aureus biofilms in vitro, which may explain why monotherapy with these agents frequently fails to eradicate biofilm infections. In fact, biofilms were resistant to antibiotics at concentrations 10-1000 times greater than the ones required to kill free-living or planktonic cells. The only antibiotics able to inhibit biofilm eradication on 50 % of isolates were ceftaroline and gentamicin. CONCLUSIONS: The results suggest that the antibiotic susceptibility patterns cannot be applied to biofilm established infections. Selection of antimicrobial therapy is a critical step in DFI and should aim at overcoming biofilm disease in order to optimize the outcomes of this complex pathology

Orexin-A/Hypocretin-1 Controls the VTA-NAc Mesolimbic Pathway via Endocannabinoid-Mediated Disinhibition of Dopaminergic Neurons in Obese Mice

Disinhibition of orexin-A/hypocretin-1 (OX-A) release occurs to several output areas of the lateral hypothalamus (LH) in the brain of leptin knockout obese ob/ob mice. In this study, we have investigated whether a similar increase of OX-A release occurs to the ventral tegmental area (VTA), an orexinergic LH output area with functional effects on dopaminergic signaling at the mesolimbic circuit. By confocal and correlative light and electron microscopy (CLEM) morphological studies coupled to molecular, biochemical, and pharmacological approaches, we investigated OX-A-mediated dopaminergic signaling at the LH-VTA-nucleus accumbens (NAc) pathway in obese ob/ob mice compared to wild-type (wt) lean littermates. We found an elevation of OX-A trafficking and release to the VTA of ob/ob mice and consequent orexin receptor-1 (OX1R)-mediated over-activation of dopaminergic (DA) neurons via phospholipase C (PLC)/diacylglycerol lipase (DAGL-α)-induced biosynthesis of the endocannabinoid 2-arachidonoylglycerol (2-AG). In fact, by retrograde signaling to cannabinoid receptor type 1 (CB1R) at inhibitory inputs to DA neurons, 2-AG inhibited GABA release thus inducing an increase in DA concentration in the VTA and NAc of ob/ob mice. This effect was prevented by the OX1R antagonist SB-334867 (30 mg/Kg, i.p.), or the CB1R antagonist AM251 (10 mg/Kg, i.p.) and mimicked by OX-A injection (40 μg/Kg, i.p.) in wt lean mice. Enhanced DA signaling to the NAc in ob/ob mice, or in OX-A-injected wt mice, was accompanied by β-arrestin2-mediated desensitization of dopamine D2 receptor (D2R) in a manner prevented by SB-334867 or the D2R antagonist L741 (1.5 mg/Kg, i.p.). These results further support the role of OX-A signaling in the control of neuroadaptive responses, such as compulsive reward-seeking behavior or binge-like consumption of high palatable food, and suggest that aberrant OX-A trafficking to the DA neurons in the VTA of ob/ob mice influences the D2R response at NAc, a main target area of the mesolimbic pathway, via 2-AG/CB1-mediated retrograde signaling

Molecular Typing, Virulence Traits and Antimicrobial Resistance of Diabetic Foot Staphylococci

Diabetes mellitus is a major chronic disease that continues to increase significantly. One of the most important and costly complications of diabetes are foot infections that may be colonized by pathogenic and antimicrobial resistant bacteria, harboring several virulence factors, that could impair its successful treatment. Staphylococcus aureus is one of the most prevalent isolate in diabetic foot infections, together with aerobes and anaerobes

Invasive infections due to Streptococcus pyogenes: seasonal variation of severity and clinical characteristics, Iceland, 1975 to 2012.

To access publisher's full text version of this article click on the hyperlink at the bottom of the pageEpidemiology and clinical characteristics of invasive Group A streptococcal infections (IGASI) are highly variable. Long-term studies are needed to understand the interplay between epidemiology and virulence. In a population-based study of IGASI in Iceland from 1975 to 2012, 288 cases were identified by positive cultures from normally sterile body sites. Charts were reviewed retrospectively and emm-types of viable Streptococcus pyogenes isolates (n=226) determined. Comparing the first and last decade of the study period, IGASI incidence increased from 1.09 to 3.96 cases per 100,000 inhabitants per year. The most common were emm types 1 (25%), 28 (11%) and 89 (11%); emm1 strains were most likely to cause severe infections. Infections in adults were significantly more likely to be severe during the seasonal peak from January to April (risk ratio: 2.36, 95% confidence interval: 1.34–4.15). Significant seasonal variability in severity was noted among patients with diagnosis of sepsis, respiratory infection and cellulitis, with 38% of severe infections in January to April compared with 16% in other months (p<0.01). A seasonal increase in severity of IGASI suggested that generalised seasonal increase in host susceptibility, rather than introduction of more virulent strains may play a role in the pathogenesis of these potentially fatal infections.Icelandic Center for Research, Rannis/100436021 Landspitali University Hospital Science Fun