2,979 research outputs found

    A case of toxicity to excess 'carbocaine' with probable reactivity of rheumatic disease

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    Cluster persistence in one-dimensional diffusion--limited cluster--cluster aggregation

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    The persistence probability, PC(t)P_C(t), of a cluster to remain unaggregated is studied in cluster-cluster aggregation, when the diffusion coefficient of a cluster depends on its size ss as D(s)∼sγD(s) \sim s^\gamma. In the mean-field the problem maps to the survival of three annihilating random walkers with time-dependent noise correlations. For γ≥0\gamma \ge 0 the motion of persistent clusters becomes asymptotically irrelevant and the mean-field theory provides a correct description. For γ<0\gamma < 0 the spatial fluctuations remain relevant and the persistence probability is overestimated by the random walk theory. The decay of persistence determines the small size tail of the cluster size distribution. For 0<γ<20 < \gamma < 2 the distribution is flat and, surprisingly, independent of γ\gamma.Comment: 11 pages, 6 figures, RevTeX4, submitted to Phys. Rev.

    Integrative DNA methylome analysis of pan-cancer biomarkers in cancer discordant monozygotic twin-pairs

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    BACKGROUND: A key focus in cancer research is the discovery of biomarkers that accurately diagnose early lesions in non-invasive tissues. Several studies have identified malignancy-associated DNA methylation changes in blood, yet no general cancer biomarker has been identified to date. Here, we explore the potential of blood DNA methylation as a biomarker of pan-cancer (cancer of multiple different origins) in 41 female cancer discordant monozygotic (MZ) twin-pairs sampled before or after diagnosis using the Illumina HumanMethylation450 BeadChip. RESULTS: We analysed epigenome-wide DNA methylation profiles in 41 cancer discordant MZ twin-pairs with affected individuals diagnosed with tumours at different single primary sites: the breast, cervix, colon, endometrium, thyroid gland, skin (melanoma), ovary, and pancreas. No significant global differences in whole blood DNA methylation profiles were observed. Epigenome-wide analyses identified one novel pan-cancer differentially methylated position at false discovery rate (FDR) threshold of 10 % (cg02444695, P = 1.8 × 10(-7)) in an intergenic region 70 kb upstream of the SASH1 tumour suppressor gene, and three suggestive signals in COL11A2, AXL, and LINC00340. Replication of the four top-ranked signals in an independent sample of nine cancer-discordant MZ twin-pairs showed a similar direction of association at COL11A2, AXL, and LINC00340, and significantly greater methylation discordance at AXL compared to 480 healthy concordant MZ twin-pairs. The effects at cg02444695 (near SASH1), COL11A2, and LINC00340 were the most promising in biomarker potential because the DNA methylation differences were found to pre-exist in samples obtained prior to diagnosis and were limited to a 5-year period before diagnosis. Gene expression follow-up at the top-ranked signals in 283 healthy individuals showed correlation between blood methylation and gene expression in lymphoblastoid cell lines at PRL, and in the skin tissue at AXL. A significant enrichment of differential DNA methylation was observed in enhancer regions (P = 0.03). CONCLUSIONS: We identified DNA methylation signatures in blood associated with pan-cancer, at or near SASH1, COL11A2, AXL, and LINC00340. Three of these signals were present up to 5 years prior to cancer diagnosis, highlighting the potential clinical utility of whole blood DNA methylation analysis in cancer surveillance

    Direct environmental lead detection by photoluminescent perovskite formation with nanogram sensitivity

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    Although the global ban on leaded gasoline has markedly reduced lead poisoning, many other environmental sources of lead exposure, such as paint, pipes, mines, and recycling sites remain. Existing methods to identify these sources are either costly or unreliable. We report here a new, sensitive, and inexpensive lead detection method that relies on the formation of a perovskite semiconductor. The method only requires spraying the material of interest with methylammonium bromide and observing whether photoluminesence occurs under UV light to indicate the presence of lead. The method detects as little as 1.0 ng/mm2 of lead by the naked eye and 50 pg/mm2 using a digital photo camera. We exposed more than 50 different materials to our reagent and found no false negatives or false positives. The method readily detects lead in soil, paint, glazing, cables, glass, plastics, and dust and could be widely used for testing the environment and preventing lead poisoning

    Kinetic Anomalies in Addition-Aggregation Processes

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    We investigate irreversible aggregation in which monomer-monomer, monomer-cluster, and cluster-cluster reactions occur with constant but distinct rates K_{MM}, K_{MC}, and K_{CC}, respectively. The dynamics crucially depends on the ratio gamma=K_{CC}/K_{MC} and secondarily on epsilon=K_{MM}/K_{MC}. For epsilon=0 and gamma<2, there is conventional scaling in the long-time limit, with a single mass scale that grows linearly in time. For gamma >= 2, there is unusual behavior in which the concentration of clusters of mass k, c_k decays as a stretched exponential in time within a boundary layer k<k* propto t^{1-2/gamma} (k* propto ln t for gamma=2), while c_k propto t^{-2} in the bulk region k>k*. When epsilon>0, analogous behaviors emerge for gamma<2 and gamma >= 2.Comment: 6 pages, 2 column revtex4 format, for submission to J. Phys.

    Fluctuation-driven insulator-to-metal transition in an external magnetic field

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    We consider a model for a metal-insulator transition of correlated electrons in an external magnetic field. We find a broad region in interaction and magnetic field where metallic and insulating (fully magnetized) solutions coexist and the system undergoes a first-order metal-insulator transition. A global instability of the magnetically saturated solution precedes the local ones and is caused by collective fluctuations due to poles in electron-hole vertex functions.Comment: REVTeX 4 pages, 3 PS figure

    Phase separation and the segregation principle in the infinite-U spinless Falicov-Kimball model

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    The simplest statistical-mechanical model of crystalline formation (or alloy formation) that includes electronic degrees of freedom is solved exactly in the limit of large spatial dimensions and infinite interaction strength. The solutions contain both second-order phase transitions and first-order phase transitions (that involve phase-separation or segregation) which are likely to illustrate the basic physics behind the static charge-stripe ordering in cuprate systems. In addition, we find the spinodal-decomposition temperature satisfies an approximate scaling law.Comment: 19 pages and 10 figure

    Telemedicine-Guided Two-Incision Lower Leg Fasciotomy Performed by Combat Medics During Tactical Combat Casualty Care:A Feasibility Study

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    IntroductionDuring tactical combat casualty care, life- and limb-saving procedures might also be performed by combat medics. This study assesses whether it is feasible to use a head-mounted display (HMD) to provide telemedicine (TM) support from a consulted senior surgeon for combat medics when performing a two-incision lower leg fasciotomy.Materials and MethodsNine combat medics were randomized into groups to perform a two-incision lower leg fasciotomy. One group used the Vuzix M400 and the second group used the RealWear HMT-1Z1. A third, control, group received no guidance. In the Vuzix M400 group and RealWear HMT-1Z1 group, a senior surgeon examined the results after the two-incision lower leg fasciotomy was finished to assess the release of compartments, possible collateral damage, and performance of the combat medics. In the control group, these results were examined by a surgical resident with expertise in two-incision lower leg fasciotomies. The resident’s operative performance questionnaire was used to score the performance of the combat medics. The telehealth usability questionnaire was used to evaluate the usability of the HMDs as perceived by the combat medics.ResultsCombat medics using an HMD were considered competent in performing a two-incision lower leg fasciotomy (Vuzix: median 3 [range 0], RealWear: median 3 [range 1]). These combat medics had a significantly better score in their ability to adapt to anatomical variances compared to the control group (Vuzix: median 3 [range 0], RealWear: median 3 [range 0], control: median 1 [range 0]; P = .018). Combat medics using an HMD were faster than combat medics in the control group (Vuzix: mean 14:14 [SD 3:41], RealWear: mean 15:42 [SD 1:58], control: mean 17:45 [SD 2:02]; P = .340). The overall satisfaction with both HMDs was 5 out of 7 (Vuzix: median 5 [range 0], RealWear: median 5 [range 1]; P = .317).ConclusionsThis study shows that it is feasible to use an HMD to provide TM support performance from a consulted senior surgeon for combat medics when performing a two-incision lower leg fasciotomy. The results of this study suggest that TM support might be useful for combat medics during tactical combat casualty care when performing life- and limb-saving procedures

    Cardiovascular-renal axis disorders in the domestic dog and cat: a veterinary consensus statement

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    OBJECTIVES There is a growing understanding of the complexity of interplay between renal and cardiovascular systems in both health and disease. The medical profession has adopted the term "cardiorenal syndrome" (CRS) to describe the pathophysiological relationship between the kidney and heart in disease. CRS has yet to be formally defined and described by the veterinary profession and its existence and importance in dogs and cats warrant investigation. The CRS Consensus Group, comprising nine veterinary cardiologists and seven nephrologists from Europe and North America, sought to achieve consensus around the definition, pathophysiology, diagnosis and management of dogs and cats with "cardiovascular-renal disorders" (CvRD). To this end, the Delphi formal methodology for defining/building consensus and defining guidelines was utilised. METHODS Following a literature review, 13 candidate statements regarding CvRD in dogs and cats were tested for consensus, using a modified Delphi method. As a new area of interest, well-designed studies, specific to CRS/CvRD, are lacking, particularly in dogs and cats. Hence, while scientific justification of all the recommendations was sought and used when available, recommendations were largely reliant on theory, expert opinion, small clinical studies and extrapolation from data derived from other species. RESULTS Of the 13 statements, 11 achieved consensus and 2 did not. The modified Delphi approach worked well to achieve consensus in an objective manner and to develop initial guidelines for CvRD. DISCUSSION The resultant manuscript describes consensus statements for the definition, classification, diagnosis and management strategies for veterinary patients with CvRD, with an emphasis on the pathological interplay between the two organ systems. By formulating consensus statements regarding CvRD in veterinary medicine, the authors hope to stimulate interest in and advancement of the understanding and management of CvRD in dogs and cats. The use of a formalised method for consensus and guideline development should be considered for other topics in veterinary medicine
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