Multivariate Calibration of Semi‐Synthetic Data Sets: Gun Powder Analysis

Quantitative analysis of multi‐component mixtures such as propellant powders is not trivial since it usually requires separation of the mixture constituents. Multivariate calibration combined to the use of semi‐synthetic data sets can eliminate the need for standard solutions preparation, and therefore allow the rapid determination of mixtures provided no intermolecular interactions occur in the systems. Multivariate compositional analyses of FTIR spectra of low‐vulnerability (LOVA), high‐energy low‐vulnerability (HELOVA) and energetic thermoplastic elastomer (ETPE) propellant powder systems were performed using the partial least‐squares (PLS) regression algorithm. All constituents except ethyl centralite (EC) were quantified. Concentrations were predicted within 1% error for the major component (1,3,5‐trinitro‐1,3,5‐triazacyclohexane or RDX), and within 5% error for the minor components (between 12 and 2% nominally by weight). LOVA, HELOVA, and ETPE gun powder samples concentrations were estimated and compared to expected compositions.     

Influence of Risk Factors for Male Infertility on Sperm Protein Composition

Male infertility is a common health problem that can be influenced by a host of lifestyle risk factors such as environment, nutrition, smoking, stress, and endocrine disruptors. These effects have been largely demonstrated on sperm parameters (e.g., motility, numeration, vitality, DNA integrity). In addition, several studies showed the deregulation of sperm proteins in relation to some of these factors. This review inventories the literature related to the identification of sperm proteins showing abundance variations in response to the four risk factors for male infertility that are the most investigated in this context: obesity, diabetes, tobacco smoking, and exposure to bisphenol-A (BPA). First, we provide an overview of the techniques used to identify deregulated proteins. Then, we summarise the main results obtained in the different studies and provide a compiled list of deregulated proteins in relation to each risk factor. Gene ontology analysis of these deregulated proteins shows that oxidative stress and immune and inflammatory responses are common mechanisms involved in sperm alterations encountered in relation to the risk factors.     

Risk assessment of war wrecks – a comprehensive approach investigating four wrecks containing munitions in the German Bight/North Sea

Shipwrecks and dumped munition continue to be a major hazard, both in the North Sea but also on a global scale. Research within the EU Interreg project North Sea Wrecks (NSW), in cooperation with the German Aerospace Centre, Institute for the Protection of Maritime Infrastructures (DLR), is generating new insights into the status of wrecks, the potential leakage of pollutants from remaining munitions loads and the effects of contamination on exposed marine organisms in the North Sea environment. Further, historical documents are generated from archives to describe ship's history and sinking scenario. These historical findings were compared to models and images of the visual inspections of the wrecks. Further, samples of water, sediment and organisms are being analysed for traces of explosives. Combining the results of these different fields of research allows for a better understanding of the environmental risks deriving from these wrecks. This process is shown below by focusing on the wreck of the German light cruiser SMS MAINZ, which sank in 1914. Data were compared to three additional wrecks situated also within the southern German Bight. Available data about the wrecks were preliminary assessed using a wreck risk model. Finally, wrecks were ranked according to their potential environmental risk.     

Calibrating SECCM measurements by means of a nanoelectrode ruler.The intrinsic oxygen reduction activity of PtNi catalyst nanoparticles

Scanning electrochemical cell microscopy(SECCM)is increasingly applied to determine the intrinsic catalytic activity of single electrocatalyst particle.This is especially feasible if the catalyst nanoparticles are large enough that they can be found and counted in post-SECCM scanning electron microscopy images.Evidently,this becomes impossible for very small nanoparticles and hence,a catalytic current measured in one landing zone of the SECCM droplet cannot be correlated to the exact number of catalyst particles.We show,that by introducing a ruler method employing a carbon nanoelectrode decorated with a countable number of the same catalyst particles from which the catalytic activity can be determined,the activity determined using SECCM from many spots can be converted in the intrinsic catalytic activity of a certain number of catalyst nanoparticles.     

The effect of average soft segment length on morphology and properties of a series of polyurethane elastomers. I. Characterization of the series

A series of eight thermoplastic polyurethane elastomers were synthesized from 4,4′-methylene diphenyl diisocyanate (MDI) and 1,4-butanediol (BDO) chain extender, with poly(hexamethylene oxide) (PHMO) macrodiol soft segments. The soft segment molecular weights employed ranged from 433 g/mol to 1180 g/mol. All materials contained 60% (w/w) of the soft segment macrodiol. Differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), wide angle x-ray diffraction (WAXD), and small angle x-ray scattering (SAXS) techniques were employed to characterize morphology. Tensile and Shore hardness tests were also performed. Materials were tested in the annealed state. It was found that an increase in segment length was accompanied by an increase in the degree of microphase separation, average interdomain spacing, hard domain order, hardness, stiffness, and opacity. DSC experiments showed the existence of several hard segment melting regions that were postulated to result from the disordering or melting of various hard segment length populations. For the system and composition ratio employed, it was found that optimum tensile properties (UTS and breaking strain) were achieved when a PHMO molecular weight of between 650 and 850 was utilized. © 1996 John Wiley & Sons, Inc.     

Bleeding and Thrombosis: Insights into Pathophysiology of Bothrops Venom-Related Hemostasis Disorders

Toxins from Bothrops venoms targeting hemostasis are responsible for a broad range of clinical and biological syndromes including local and systemic bleeding, incoagulability, thrombotic microangiopathy and macrothrombosis. Beyond hemostais disorders, toxins are also involved in the pathogenesis of edema and in most complications such as hypovolemia, cardiovascular collapse, acute kidney injury, myonecrosis, compartmental syndrome and superinfection. These toxins can be classified as enzymatic proteins (snake venom metalloproteinases, snake venom serine proteases, phospholipases A₂ and L-amino acid oxidases) and non-enzymatic proteins (desintegrins and C-type lectin proteins). Bleeding is due to a multifocal toxicity targeting vessels, platelets and coagulation factors. Vessel damage due to the degradation of basement membrane and the subsequent disruption of endothelial cell integrity under hydrostatic pressure and tangential shear stress is primarily responsible for bleeding. Hemorrhage is promoted by thrombocytopenia, platelet hypoaggregation, consumption coagulopathy and fibrin(ogen)olysis. Onset of thrombotic microangiopathy is probably due to the switch of endothelium to a prothrombotic phenotype with overexpression of tissue factor and other pro-aggregating biomarkers in association with activation of platelets and coagulation. Thrombosis involving large-caliber vessels in B. lanceolatus envenomation remains a unique entity, which exact pathophysiology remains poorly understood.     

Optimization of Blood Handling and Peripheral Blood Mononuclear Cell Cryopreservation of Low Cell Number Samples

Background: Rural/remote blood collection can cause delays in processing, reducing PBMC number, viability, cell composition and function. To mitigate these impacts, blood was stored at 4 °C prior to processing. Viable cell number, viability, immune phenotype, and Interferon-γ (IFN-γ) release were measured. Furthermore, the lowest protective volume of cryopreservation media and cell concentration was investigated. Methods: Blood from 10 individuals was stored for up to 10 days. Flow cytometry and IFN-γ ELISPOT were used to measure immune phenotype and function on thawed PBMC. Additionally, PBMC were cryopreserved in volumes ranging from 500 µL to 25 µL and concentration from 10 × 10⁶ cells/mL to 1.67 × 10⁶ cells/mL. Results: PBMC viability and viable cell number significantly reduced over time compared with samples processed immediately, except when stored for 24 h at RT. Monocytes and NK cells significantly reduced over time regardless of storage temperature. Samples with >24 h of RT storage had an increased proportion in Low-Density Neutrophils and T cells compared with samples stored at 4 °C. IFN-γ release was reduced after 24 h of storage, however not in samples stored at 4 °C for >24 h. The lowest protective volume identified was 150 µL with the lowest density of 6.67 × 10⁶ cells/mL. Conclusion: A sample delay of 24 h at RT does not impact the viability and total viable cell numbers. When long-term delays exist (>4 d) total viable cell number and cell viability losses are reduced in samples stored at 4 °C. Immune phenotype and function are slightly altered after 24 h of storage, further impacts of storage are reduced in samples stored at 4 °C.     

Neuroprotection Mediated by Human Blood Plasma in Mouse Hippocampal Slice Cultures and in Oxidatively Stressed Human Neurons

Neuroprotection from oxidative stress is critical during neuronal development and maintenance but also plays a major role in the pathogenesis and potential treatment of various neurological disorders and neurodegenerative diseases. Emerging evidence in the murine system suggests neuroprotective effects of blood plasma on the aged or diseased brain. However, little is known about plasma-mediated effects on human neurons. In the present study, we demonstrate the neuroprotective effect mediated by human plasma and the most abundant plasma–protein human serum albumin against oxidative stress in glutamatergic neurons differentiated from human neural crest-derived inferior turbinate stem cells. We observed a strong neuroprotective effect of human plasma and human serum albumin against oxidative stress-induced neuronal death on the single cell level, similar to the one mediated by tumor necrosis factor alpha. Moreover, we detected neuroprotection of plasma and human serum albumin against kainic acid-induced excitatory stress in ex vivo cultured mouse hippocampal tissue slices. The present study provides deeper insights into plasma-mediated neuroprotection ultimately resulting in the development of novel therapies for a variety of neurological and, in particular, neurodegenerative diseases.     

Tracing Change: Patterns in Landscape Architecture

For Simon Swaffield , landscape design can be regarded as the product of distinctive patterns formed through the intersection of site, technology and idealised nature. Across time and cultures, the interpretation of nature has shifted endlessly, and with it the manner in which the natural world is conceived, transformed and represented. Given its history, what might also be the future patterns of landscape design?. Copyright © 2009 John Wiley & Sons, Ltd.