Inhibitors of the NMDA-Nitric Oxide Signaling Pathway Protect Against Neuronal Atrophy and Synapse Loss Provoked by l-alpha Aminoadipic Acid-treated Astrocytes

The impact of treating astrocytes with the astrocytic toxin l-alpha amino adipic acid (L-AAA) on neuronal outgrowth, complexity and synapse formation was assessed, using a model of astrocyte-neuronal interaction. Treatment of rat primary cortical neurons with conditioned media (CM) derived from astrocytes treated with L-AAA reduced neuronal complexity and synapse formation. L-AAA provoked a reduction in the expression of glial fibrillary acid protein (GFAP) and a reduction in ATP-linked mitochondrial respiration in astrocytic cells. As the NMDA-R/PSD-95/NOS signaling pathway is implicated in regulating the structural plasticity of neurons, treatment of neuronal cultures with the neuronal nitric oxide synthase (nNOS) inhibitor 1-[2-(trifluoromethyl)phenyl] imidazole (TRIM) [100 nM] was assessed and observed to protect against L-AAA-treated astrocytic CM-induced reduction in neuronal complexity and synapse loss. Treatment with the NMDA-R antagonist ketamine protected against the CM-induced loss of synapse formation whereas the novel PSD-95/nNOS inhibitors 2-((1H-benzo[d] [1,2,3]triazol-5-ylamino) methyl)-4,6-dichlorophenol (IC87201) and 4-(3,5-dichloro-2-hydroxy-benzylamino)-2-hydroxybenzoic acid (ZL006) protected against synapse loss with partial protection against reduced neurite outgrowth. Furthermore, L-AAA delivery to the pre-limbic cortex (PLC) of mice was found to increase dendritic spine density and treatment with ZL006 reduced this effect. In summary, L-AAA-induced astrocyte impairment leads to a loss of neuronal complexity and synapse loss in vitro and increased dendritic spine density in vivo that may be reversed by inhibitors of the NMDA-R/PSD-95/NOS pathway. The results have implications for understanding astrocytic-neuronal interaction and the search for drug candidates that may provide therapeutic approaches for brain disorders associated with astrocytic histopathology.

Is the aquatic environment sufficiently protected from chemicals discharged with treated ballast water from vessels worldwide? - A decadal environmental perspective and risk assessment

Ballast water managements systems (BWMS) installed on vessels may use active substances to inactivate or kill organisms in the ballast water. This paper provides new insights in this global issue - discharge of hazardous disinfection by-products with ballast water and related risk assessment for the environment. Considering the possible extent of this issue, the International Maritime Organization (IMO) engaged the Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP)-Ballast Water Working Group (BWWG) to oversee the evaluation process of BWMS that make use of active substances to prevent negative effects. We analysed all BWMS that received IMO final approval over a decade until 2017 and provide an overview of active substances used for ballast water treatment and disinfection by-products in the discharged ballast water. A risk assessment was conducted using the GESAMP-BWWG methodology for two very different commercial ports (Koper, Slovenia and Hamburg, Germany). Some relevant chemicals (chloropicrin, monochloroacetic acid, and dibromoacetonitrile) and other chemicals (isocyanuric acid and sodium thiosulphate) reached levels of concern, indicating a risk for aquatic organisms after discharge of that ballast water. From this analysis, it became clear GESAMP-BWWG worst-case scenario assumptions do not fully account for the potential environmental risks. We provide recommendations how to make this risk assessment more robust, recommend further research, and urge for policy as well as regulatory responses.

Breast magnetic resonance imaging: are those who need it getting it?

BACKGROUND

Indications for breast magnetic resonance imaging (mri), a very sensitive but less-specific tool for breast investigation, remain controversial, and accessibility is limited. The purposes of our study were to determine the proportion of breast mri exams performed for various clinical indications, to assess the wait times for breast mri, and to create a list of evidence-based indications for breast mri.

METHODS

The indications for breast mri exams performed in September 2013 at our academic centre were audited. A multidisciplinary meeting held in May 2014 established a list of evidence-based indications for breast mri, after which, in September 2014 and 2015, breast mri exams were re-audited for clinical indications, and pending requests were calculated.

RESULTS

In September 2013, surveillance of women with a prior diagnosis of breast cancer represented 21% of breast mri exams (24 of 113), with preoperative staging representing 18% of exams (20 of 113) and high-risk screening representing 12% (13 of 113). Of pending mri requests, 230 were within the recommended delay period, and 457 exceeded the recommended delay. After elaboration of evidence-based guidelines, repeat audits in September 2014 and September 2015 showed that mri performed for women with a prior breast cancer diagnosis represented 23% (33 of 141) and 7% (10 of 143) of exams respectively, with preoperative staging having declined to 9% (13 of 141) and 11% (16 of 143) of exams, and high-risk screening having increased to 36% (51 of 141) and 46% (66 of 143) of exams. Overall, wait times were improved for all breast mri indications.

CONCLUSIONS

Through multidisciplinary discussion, we actualized a list of breast mri indications, prioritized requests more adequately, and improved wait times.

Crystal Phases in Hybrid Metal-Semiconductor Nanowire Devices

We investigate the metallic phases observed in hybrid metal-GaAs nanowire devices obtained by controlled thermal annealing of Ni/Au electrodes. Devices are fabricated onto a SiN membrane compatible with transmission electron microscopy studies. Energy dispersive X-ray spectroscopy allows us to show that the nanowire body includes two Ni-rich phases that thanks to an innovative use of electron diffraction tomography can be unambiguously identified as Ni₃GaAs and Ni₅As₂ crystals. The mechanisms of Ni incorporation leading to the observed phenomenology are discussed.

On the thermodynamic path enabling a room-temperature, laser-assisted graphite to nanodiamond transformation

Nanodiamonds are the subject of active research for their potential applications in nano-magnetometry, quantum optics, bioimaging and water cleaning processes. Here, we present a novel thermodynamic model that describes a graphite-liquid-diamond route for the synthesis of nanodiamonds. Its robustness is proved via the production of nanodiamonds powders at room-temperature and standard atmospheric pressure by pulsed laser ablation of pyrolytic graphite in water. The aqueous environment provides a confinement mechanism that promotes diamond nucleation and growth, and a biologically compatible medium for suspension of nanodiamonds. Moreover, we introduce a facile physico-chemical method that does not require harsh chemical or temperature conditions to remove the graphitic byproducts of the laser ablation process. A full characterization of the nanodiamonds by electron and Raman spectroscopies is reported. Our model is also corroborated by comparison with experimental data from the literature.

Nucleation and growth mechanism of self-catalyzed InAs nanowires on silicon

We report on the nucleation and growth mechanism of self-catalyzed InAs nanowires (NWs) grown on Si (111) substrates by chemical beam epitaxy. Careful choices of the growth parameters lead to In-rich conditions such that the InAs NWs nucleate from an In droplet and grow by the vapor-liquid-solid mechanism while sustaining an In droplet at the tip. As the growth progresses, new NWs continue to nucleate on the Si (111) surface causing a spread in the NW size distribution. The observed behavior in NW nucleation and growth is described within a suitable existing theoretical model allowing us to extract relevant growth parameters. We argue that these results provide useful guidelines to rationally control the growth of self-catalyzed InAs NWs for various applications.

Plastic mulching in agriculture. Trading short-term agronomic benefits for long-term soil degradation?

Plastic mulching has become a globally applied agricultural practice for its instant economic benefits such as higher yields, earlier harvests, improved fruit quality and increased water-use efficiency. However, knowledge of the sustainability of plastic mulching remains vague in terms of both an environmental and agronomic perspective. This review critically discusses the current understanding of the environmental impact of plastic mulch use by linking knowledge of agricultural benefits and research on the life cycle of plastic mulches with direct and indirect implications for long-term soil quality and ecosystem services. Adverse effects may arise from plastic additives, enhanced pesticide runoff and plastic residues likely to fragment into microplastics but remaining chemically intact and accumulating in soil where they can successively sorb agrochemicals. The quantification of microplastics in soil remains challenging due to the lack of appropriate analytical techniques. The cost and effort of recovering and recycling used mulching films may offset the aforementioned benefits in the long term. However, comparative and long-term agronomic assessments have not yet been conducted. Furthermore, plastic mulches have the potential to alter soil quality by shifting the edaphic biocoenosis (e.g. towards mycotoxigenic fungi), accelerate C/N metabolism eventually depleting soil organic matter stocks, increase soil water repellency and favour the release of greenhouse gases. A substantial process understanding of the interactions between the soil microclimate, water supply and biological activity under plastic mulches is still lacking but required to estimate potential risks for long-term soil quality. Currently, farmers mostly base their decision to apply plastic mulches rather on expected short-term benefits than on the consideration of long-term consequences. Future interdisciplinary research should therefore gain a deeper understanding of the incentives for farmers and public perception from both a psychological and economic perspective in order to develop new support strategies for the transition into a more environment-friendly food production.

Effectiveness of Serial Measurement of Differential Pressure in Closed Tibial Diaphyseal Fractures in Diagnosing Acute Compartment Syndrome using Whiteside's Technique

Acute Compartment Syndrome is a limb-threatening emergency and it occurs most commonly after fractures. The aim of our study is to find out the effectiveness of serial measurement of differential pressure in closed tibial diaphyseal fractures, in diagnosing acute compartment syndrome, using Whiteside’s technique. A total of 52 cases in the age group of 15 to 55 years admitted with closed fractures were studied for serial compartment pressure as well as serial differential pressure. Eight patients had persistent compartment pressure > 40mmHg, out of which only two patients had persistent differential pressure < 30mmHg and these two patients underwent fasciotomy. Thus, by measuring the compartment pressure serially and calculating differential pressure serially, acute compartment syndrome can be diagnosed or ruled out with higher precision, so that unnecessary fasciotomies can be avoided.

Delayed Anaphylaxis to the flu vaccine unrelated to known non-viral components

On February 4, 2010 the CDC's Advisory Committee on Immunization Practices voted for universal flu vaccination to expand protection against the flu throughout the United States. In addition to this administration expansion, six new influenza vaccines have been introduced into the market possibly introducing new allergenic potentials. We report two cases of delayed anaphylaxis to the flu vaccine.

Genotypes of hepatitis C virus in the Indian sub-continent: a decade-long experience from a tertiary care hospital in South India

BACKGROUND

Hepatitis C virus (HCV) is a leading cause of chronic liver disease (CLD) that can progress to cirrhosis and hepatocellular carcinoma. Genotypes of HCV can vary in pathogenicity and can impact on treatment outcome.

OBJECTIVES

To study the different genotypes among patients with HCV related CLD attending a tertiary care hospital in south India during 2002-2012.

STUDY DESIGN

Study subjects were those referred to clinical virology from the liver clinic. Genotyping was performed using the genotype specific core primers in nested polymerase chain reaction (PCR), 5' non-coding regions based PCR- restriction fragment length polymorphism and NS5B sequencing methods. With the latter method, obtained sequences were compared with published GenBank sequences to determine the genotype.

RESULTS

Of the 451 samples tested, HCV genotype 3 was found to be the most predominant (63.85%). Other genotypes detected were genotype 1 (25.72%), genotype 2 (0.002%), genotype 4 (7.5%) and genotype 6 (2.7%). Genotype 3 was the common genotype in patients from Eastern India while genotype 1 and 4 were mainly seen in South Indian patients. Genotype 6 was seen exclusively in patients from North-Eastern India. Two other patients were infected with recombinants of genotype 1 and 2.

CONCLUSIONS

In this study spanning a decade, HCV genotype 3 and genotype 1 were found to be the predominant genotypes in the Indian sub-continent. Genotype 4 and genotype 6 appeared to show some geographic restriction. A continued monitoring of HCV genotypes is essential for the optimum management of these chronically infected patients. In addition, knowledge of circulating genotypes could impact on future vaccine formulations.

The influence of transport layers on the photodegradation stability of polymer solar cell structures

A light exposure degradation study of electrically active polymers – high-glass-transition-temperature poly(1,4-phenylenevinylene) (Tg-PPV); poly(3-hexylthiophene-2,5-diyl) (P3HT); and poly(2-methoxy-5-(3′-7′- dimethyloctyloxy)-1,4-phenylenevinylene) (MDMO-PPV) – in pure form and blends with [6,6]-phenyl C61-butyric acid methyl ester (PCBM) was conducted to assess the influence of the employed transport layers on the materials’ photodegradation stability. Devices were prepared on quartz glass and silicon (Si) substrates with a transport layer prepared from poly(3,4-ethylenedioxythiophene):poly(4-styrene sulfonate) (PEDOT:PSS) or titanium dioxide (TiO2). Photodegradation processes in ambient air demonstrated that the polymers were thermally stable in the dark; thus, the material deteriorations not only were caused by thermal stress, but also from light-induced processes. Degradation processes of pure polymers may be considered as fast – in the order of hours – but retardable by blending of polymers with PCBM. The deposition of polymer blends on an additional layer of PEDOT:PSS or TiO2 revealed that the polymer blends studied in this work (except for P3HT) presented higher stability against polymer chain scission when deposited onto the TiO2 layer. Kinetic analysis undertaken during this work revealed that the photodegradation processes were followed by two degradation steps. Degradation kinetics were evaluated according to a Perrin-like model for absorption assessments and according to simple exponential for emission measurements.

The physico-chemical properties and biostimulative activities of humic substances regenerated from lignite

The positive effect of humic acids on the growth of plant roots is well known, however, the mechanisms and role of their physical structure in these processes have not been fully explained yet. In this work, South-Moravian lignite was oxidized by means of nitric acid and hydrogen peroxide to produce a set of regenerated humic acids. The elemental composition, solid state stability and solution characteristics were determined and correlated in vitro with their biological activity. A modified hydroponic method was applied to determine the effects of their potassium salts on Zea mays seedlings roots with respect to the plant weight, root length, root division, and starch and protein content. The relations between the determined parameters were evaluated through Principal Component Analysis and Pearson's correlation coefficients. The results indicated that the most important factor determining the biological activity of South-Moravian lignite potassium humates is related to the nature of self-assemblies, while the chemical composition had no direct connection with the root growth of Zea mays seedlings. It was demonstrated a controlled processing that provided humic substances with different chemical and physicochemical properties and variable biological activity.