Membrane consisting of polyquaternary amine ion exchange polymer network interpenetrating the chains of thermoplastic matrix polymer

An ion exchange membrane was formed from a solution containing dissolved matrix polymer and a set of monomers which are capable of reacting to form a polyquaternary ion exchange material; for example vinyl pyride and a dihalo hydrocarbon. After casting solution and evaporation of the volatile component's, a relatively strong ion exchange membrane was obtained which is capable of removing anions, such as nitrate or chromate from water. The ion exchange polymer forms an interpenetrating network with the chains of the matrix polymer

Dependence of stress rupture and superplasticity on structure in Co-W alloys, part I

Dependence of stress rupture and superplasticity on structure in Co-W alloy

Observation of Single Transits in Supercooled Monatomic Liquids

A transit is the motion of a system from one many-particle potential energy valley to another. We report the observation of transits in molecular dynamics (MD) calculations of supercooled liquid argon and sodium. Each transit is a correlated simultaneous shift in the equilibrium positions of a small local group of particles, as revealed in the fluctuating graphs of the particle coordinates versus time. This is the first reported direct observation of transit motion in a monatomic liquid in thermal equilibrium. We found transits involving 2 to 11 particles, having mean shift in equilibrium position on the order of 0.4 R_1 in argon and 0.25 R_1 in sodium, where R_1 is the nearest neighbor distance. The time it takes for a transit to occur is approximately one mean vibrational period, confirming that transits are fast.Comment: 19 pages, 8 figure

Low-energy interaction of composite spin-half systems with scalar and vector fields

We consider a composite spin-half particle moving in spatially-varying scalar and vector fields. The vector field is assumed to couple to a conserved charge, but no assumption is made about either the structure of the composite or its coupling to the scalar field. A general form for the piece of the spin-orbit interaction of the composite with the scalar and vector fields which is first-order in momentum transfer ${\bf Q}$ and second-order in the fields is derived.Comment: 10 pages, RevTe

Assessment of free-living nitrogen fixing microorganisms for commercial nitrogen fixation

Ammonia production by Klebsiella pneumoniae is not economical with present strains and improving nitrogen fixation to its theoretical limits in this organism is not sufficient to achieve economic viability. Because the value of both the hydrogen produced by this organism and the methane value of the carbon source required greatly exceed the value of the ammonia formed, ammonia (fixed nitrogen) should be considered the by-product. The production of hydrogen by KLEBSIELLA or other anaerobic nitrogen fixers should receive additional study, because the activity of nitrogenase offers a significant improvement in hydrogen production. The production of fixed nitrogen in the form of cell mass by Azotobacter is also uneconomical and the methane value of the carbon substrate exceeds the value of the nitrogen fixed. Parametric studies indicate that as efficiencies approach the theoretical limits the economics may become competitive. The use of nif-derepressed microorganisms, particularly blue-green algae, may have significant potential for in situ fertilization in the environment

Lipid-absorbing Polymers

The removal of bile acids and cholesterol by polymeric absorption is discussed in terms of micelle-polymer interaction. The results obtained with a polymer composed of 75 parts PEO and 25 parts PB plus curing ingredients show an absorption of 305 to 309%, based on original polymer weight. Particle size effects on absorption rate are analyzed. It is concluded that crosslinked polyethylene oxide polymers will absorb water, crosslinked polybutadiene polymers will absorb lipids; neither polymer will absorb appreciable amounts of lipids from micellar solutions of lipids in water

Peripheral nerve demyelination and neuropathic pain

Chronic neuropathic pain, characterised by allodynia (perception of innocuous stimuli as painful) and hyperalgesia (facilitated responses to painftil stimuli), is poorly understood and is usually resistant to classical analgesics. Such abnormal pain phenomena can be associated with human demyelinating conditions such as Charcot-Marie-Tooth disease. Using mouse models of peripheral nerve demyelination, we have provided evidence for the consequent establishment of neuropathic pain and investigated possible underlying mechanisms. The first model investigated was the Prx-mi\\ mouse. The murine periaxin gene (Prx) is expressed in Schwann cells and encodes L- and S-periaxin, two abundant PDZ-domain proteins thought to have a role in stabilisation of myelin in the peripheral nervous system (PNS). Prx-null mice show progressive demyelination in peripheral nerves and electrophysiological investigations indicate the presence of spontaneous action potential discharge; abnormal activity thought to be critical for the development of persistent pain states. Consistent with the time course of demyelination, Rrx-null mice display an increased behavioural reflex sensitivity to cutaneous mechanical and noxious thermal stimulation. To further investigate the link between demyelination of peripheral nerves and neuropathic pain, we have also characterised a novel model of focal peripheral nerve demyelinating neuropathy. Focal demyelination of the sciatic or saphenous nerve was induced with lysolecithin (lysophosphatidylcholine) and resulted in an increased behavioural reflex sensitivity to both thermal and mechanical tests, peaking at 9-14 days following treatment. Nerve morphology was investigated using light and electron microscopy, which revealed 30- 40% demyelination of the treated nerve, (without lysolecithin-treated axon loss) coinciding with peak behavioural changes. Changes in the excitability of saphenous nerves were revealed, with spontaneous action potential discharge of 2-3 impulses per second present at peak behavioural change. No associated change in peripheral activation thresholds or conduction velocity was observedIn both models, immunohistochemical investigations revealed no cell loss in the dorsal root ganglia (DRG) and no evidence for axonal damage. Similar methods revealed changes in the expression of neuropeptide Y, and the sodium channels Nav1.3 and Nav1.8 in DRG neurones. Such changes may account for increased nerve excitability and are known to occur in other models of nerve injury. However, these changes in the demyelinating models occur in a more restricted manner, specifically in the cells of formerly myelinated fibres. Intrathecal injections of the selective NMDA receptor antagonist, [R]-CPP, indicated that NMDA receptor-dependent changes are crucial for the development of a neuropathic pain like state following peripheral nerve demyelination. Intrathecal administration of pharmacological agents indicated a role for the transcription factor NFkB in the production of the behavioural reflex sensitivity of lysolecithin-treated mice, as well as identifying the endogenous cannabinoid system as an effective inhibitory regulator and potential analgesic target.This study describes the first mouse models of peripheral nerve demyelination designed for the study of neuropathic pain and reveals phenotypic changes in DRG, which may contribute to the development of a neuropathic pain-like state. Therefore, these models may be useful for the evaluation of novel therapeutic targets for the treatment of demyelination-associated neuropathic pain

Evidence Inference 2.0: More Data, Better Models

How do we most effectively treat a disease or condition? Ideally, we could consult a database of evidence gleaned from clinical trials to answer such questions. Unfortunately, no such database exists; clinical trial results are instead disseminated primarily via lengthy natural language articles. Perusing all such articles would be prohibitively time-consuming for healthcare practitioners; they instead tend to depend on manually compiled systematic reviews of medical literature to inform care. NLP may speed this process up, and eventually facilitate immediate consult of published evidence. The Evidence Inference dataset was recently released to facilitate research toward this end. This task entails inferring the comparative performance of two treatments, with respect to a given outcome, from a particular article (describing a clinical trial) and identifying supporting evidence. For instance: Does this article report that chemotherapy performed better than surgery for five-year survival rates of operable cancers? In this paper, we collect additional annotations to expand the Evidence Inference dataset by 25\%, provide stronger baseline models, systematically inspect the errors that these make, and probe dataset quality. We also release an abstract only (as opposed to full-texts) version of the task for rapid model prototyping. The updated corpus, documentation, and code for new baselines and evaluations are available at http://evidence-inference.ebm-nlp.com/.Comment: Accepted as workshop paper into BioNLP Updated results from SciBERT to Biomed RoBERT

Distribution, morphology, and genetic affinities of dwarf embedded Fucus populations from the Northwest Atlantic Ocean

Dwarf embedded Fucus populations in the Northwest Atlantic Ocean are restricted to the upper intertidal zone in sandy salt marsh environments; they lack holdfasts and are from attached parental populations of F. spiralis or F. spiralis x F. vesiculosus hybrids after breakage and entanglement with halophytic marsh grasses. Dwarf forms are dichotomously branched, flat, and have a mean overall length and width of 20.3 and 1.3 mm, respectively. Thus, they are longer than Irish (mean 9.3 mm) and Alaskan (mean 15.0 mm) populations identified as F cottonii. Reciprocal transplants of different Fucus taxa in a Maine salt marsh confirm that F spiralis can become transformed into dwarf embedded thalli within the high intertidal zone, while the latter can grow into F. s. ecad lutarius within the mid intertidal zone. Thus, vertical transplantation can modify fucoid morphology and result in varying ecads. Microsatellite markers indicate that attached F spiralis and F vesiculosus are genetically distinct, while dwarf forms may arise via hybridization between the two taxa. The ratio of intermediate to species-specific-genotypes decreased with larger thalli. Also, F s. ecad lutarius consists of a mixture of intermediate and pure genotypes, while dwarf thalli show a greater frequency of hybrids