Darboux transformations for a Bogoyavlenskii equation in 2+1 dimensions

We use the singular manifold method to obtain the Lax pair, Darboux transformations and soliton solutions for a (2+1) dimensional integrable equation.Comment: 7 pages, latex, to appear in the proceedings of the meeting "Nonlinearity and Integrability" (Gallipoli, Italy, July 1999

Route Towards a Label-free Optical Waveguide Sensing Platform Based on Lossy Mode Resonances

According to recent market studies of the North American company Allied Market Research, the field of photonic sensors is an emerging strategic field for the following years and it is expected to garner $18 billion by 2021. The integration of micro and nanofabrication technologies in the field of sensors has allowed the development of new technological concepts such as lab-on-a-chip, which have achieved extraordinary advances in terms of detection and applicability, for example in the field of biosensors. This continuous development has allowed that equipment consisting of many complex devices that occupied a whole room a few years ago, at present it is possible to handle them in the palm of the hand; that formerly long duration processes are carried out in a matter of milliseconds and that a technology previously dedicated solely to military or scientific uses is available to the vast majority of consumers. The adequate combination of micro and nanostructured coatings with optical fiber sensors has permitted us to develop novel sensing technologies, such as the first experimental demonstration of lossy mode resonances (LMRs) for sensing applications, with more than one hundred citations and related publications in high rank journals and top conferences. In fact, fiber optic LMR-based devices have been proven as devices with one of the highest sensitivity for refractometric applications. Refractive index sensitivity is an indirect and simple indicator of how sensitive the device is to chemical and biological species, topic where this proposal is focused. Consequently, the utilization of these devices for chemical and biosensing applications is a clear opportunity that could open novel and interesting research lines and applications as well as simplify current analytical methodologies. As a result, on the basis of our previous experience with LMR based sensors to attain very high sensitivities, the objective of this paper is presenting the route for the development of label-free optical waveguide sensing platform based on LMRs that enable to explore the limits of this technology for bio-chemosensing applications

Evidence of a Causal Relationship between Serum Thyroid-Stimulating Hormone and Osteoporotic Bone Fractures

OBJECTIVE: We aimed to validate the association of genome-wide association study (GWAS)-identified loci and polygenic risk score with serum thyroid-stimulating hormone (TSH) concentrations and the diagnosis of hypothyroidism. Then, the causal relationship between serum TSH and osteoporotic bone fracture risk was tested. METHODS: A cross-sectional study was done among patients of European Caucasian ethnicity recruited in Tayside (Scotland, UK). Electronic medical records (EMRs) were used to identify patients and average serum TSH concentration and linked to genetic biobank data. Genetic associations were performed by linear and logistic regression models. One-sample Mendelian randomization (MR) was used to test causality of serum TSH on bone fracture risk. RESULTS: Replication in 9,452 euthyroid individuals confirmed known loci previously reported. The 58 polymorphisms accounted for 11.08% of the TSH variation (p < 1e−04). TSH-GRS was directly associated with the risk of hypothyroidism with an odds ratio (OR) of 1.98 for the highest quartile compared to the first quartile (p = 2.2e−12). MR analysis of 5,599 individuals showed that compared with those in the lowest tertile of the TSH-GRS, men in the highest tertile had a decreased risk of osteoporotic bone fracture (OR = 0.59, p = 2.4e−03), while no difference in a similar comparison was observed in women (OR = 0.93, p = 0.61). Sensitivity analysis yielded similar results. CONCLUSIONS: EMRs linked to genomic data in large populations allow replication of GWAS discoveries without additional genotyping costs. This study suggests that genetically raised serum TSH concentrations are causally associated with decreased bone fracture risk in men

Childhood energy intake is associated with nonalcoholic fatty liver disease in adolescents

Background: Greater adiposity is an important risk factor for nonalcoholic fatty liver disease (NAFLD). Thus, it is likely that dietary intake is involved in the development of the disease. Prospective studies assessing the relation between childhood dietary intake and risk of NAFLD are lacking. Objective: This study was designed to explore associations between energy, carbohydrate, sugar, starch, protein, monounsaturated fat, polyunsaturated fat, saturated fat, and total fat intake by youth at ages 3, 7, and 13 y and subsequent (mean age: 17.8 y) ultrasound scan (USS)–measured liver fat and stiffness and serum alanine aminotransferase, aspartate aminotransferase, and γ-glutamyltransferase. We assessed whether observed associations were mediated through fat mass at the time of outcome assessment. Methods: Participants were from the Avon Longitudinal Study of Parents and Children. Trajectories of energy and macronutrient intake from ages 3–13 y were obtained with linear-spline multilevel models. Linear and logistic regression models examined whether energy intake and absolute and energy-adjusted macronutrient intake at ages 3, 7, and 13 y were associated with liver outcomes. Results: Energy intake at all ages was positively associated with liver outcomes; for example, the odds of having a USS-measured liver fat per 100 kcal increase in energy intake at age 3 y were 1.79 (95% CI: 1.14, 2.79). Associations between absolute macronutrient intake and liver outcomes were inconsistent and attenuated to the null after adjustment for total energy intake. The majority of associations attenuated to the null after adjustment for fat mass at the time liver outcomes were assessed. Conclusion: Higher childhood and early adolescent energy intake is associated with greater NAFLD risk, and the macronutrients from which energy intake is derived are less important. These associations appear to be mediated, at least in part, by fat mass at the time of outcome assessment

Coronary artery calcification on routine CT has prognostic and treatment implications for all ages

Aims: Guidelines have recommended reporting coronary artery calcification (CAC) if present on chest CT imaging regardless of indication. This study assessed CAC prevalence, prognosis and the potential clinical impact of its reporting. Methods: We performed a single-centre retrospective analysis (January-December 2015) of 1400 chest CTs (200 consecutive within each age group: &lt;40, 40-49, 50-59, 60-69, 70-79, 80-89, ≥90). CTs were re-reviewed for CAC presence and severity and excluded if prior coronary intervention. Comorbidities, statin prescription and clinical outcomes (myocardial infarction [MI], stroke, all-cause mortality) were recorded. The impact of reporting CAC was assessed against pre-existing statin prescriptions. Results: 1343 patients were included (mean age 63±20 years, 56% female). Inter- and intra-observer variability for CAC presence at re-review was almost perfect (κ 0.89, p &lt; 0.001; κ 0.90, p &lt; 0.001) and for CAC grading was substantial and almost perfect (κ 0.68, p &lt; 0.001; κ 0.91, p &lt; 0.001). CAC was observed in 729/1343 (54%), more frequently in males (p &lt; 0.001) and rising age (p &lt; 0.001). A high proportion of patients with CAC in all age groups had no prior statin prescription (range: 42% [80-89] to 100% [&lt;40]). The ‘number needed to report’ CAC presence to potentially impact management across all ages was 2. 689 (51%) patients died (median follow-up 74-months). CAC presence was associated with risk of MI, stroke and all-cause mortality (p &lt; 0.001). After adjusting for confounders, severe calcification predicted risk of all-cause mortality (HR 1.8 [1.2-2.5], p = 0.002). Conclusion: Grading of CAC was reproducible, and although prevalence rose with age, prognostic and treatment implications were maintained in all ages.</p

Frozen cancellous bone allografts: positive cultures of implanted grafts in posterior fusions of the spine

We have carried out a study on the behaviour pattern of implanted allografts initially stored in perfect conditions (aseptically processed, culture-negative and stored at -80 degrees C) but which presented positive cultures at the implantation stage. There is no information available on how to deal with this type of situation, so our aim was to set guidelines on the course of action which would be required in such a case. This was a retrospective study of 112 patients who underwent a spinal arthrodesis and in whom a total of 189 allograft pieces were used. All previous bone and blood cultures and tests for hepatitis B and C, syphilis and HIV (via PCR techniques) were negative. The allografts were stored by freezing them at -80 degrees C. A sample of the allograft was taken for culture in the operating theatre just before its implantation in all cases. The results of the cultures were obtained 3-5 days after the operation. There were 22 allografts with positive culture results (12%) after implantation. These allografts were implanted in 16 patients (14%). Cultures were positive for staphylococci coagulase negative (ECN) in 10 grafts (46%), Pseudomonas stutzeri in two grafts (9%), Corynebacterium jeikeium in two grafts (9%), staphylococci coagulase positive in two grafts (9%) and for each of the following organisms in one case each (4%): Corynebacterium spp., Actinomyces odontolyticus, Streptococcus mitis, Peptostreptococcus spp., Rhodococcus equi and Bacillus spp. No clinical infection was seen in any of these patients. Positive cultures could be caused by non-detected contamination at harvesting, storing or during manipulation before implantation. The lack of clinical signs of infection during the follow-up of our patients may indicate that no specific treatment different from our antibiotic protocol is required in the case of positive culture results of a graft piece after implantation

Canine respiratory coronavirus employs caveolin-1-mediated pathway for internalization to HRT-18G cells

Canine respiratory coronavirus (CRCoV), identified in 2003, is a member of the Coronaviridae family. The virus is a betacoronavirus and a close relative of human coronavirus OC43 and bovine coronavirus. Here, we examined entry of CRCoV into human rectal tumor cells (HRT-18G cell line) by analyzing co-localization of single virus particles with cellular markers in the presence or absence of chemical inhibitors of pathways potentially involved in virus entry. We also targeted these pathways using siRNA. The results show that the virus hijacks caveolin-dependent endocytosis to enter cells via endocytic internalization

Subcellular fractionation method to study endosomal trafficking of Kaposi’s sarcoma-associated herpesvirus

Background Virus entry involves multiple steps and is a highly orchestrated process on which successful infection collectively depends. Entry processes are commonly analyzed by monitoring internalized virus particles via Western blotting, polymerase chain reaction, and imaging techniques that allow scientist to track the intracellular location of the pathogen. Such studies have provided abundant direct evidence on how viruses interact with receptor molecules on the cell surface, induce cell signaling at the point of initial contact with the cell to facilitate internalization, and exploit existing endocytic mechanisms of the cell for their ultimate infectious agenda. However, there is dearth of knowledge in regards to trafficking of a virus via endosomes. Herein, we describe an optimized laboratory procedure to isolate individual organelles during different stages of endocytosis by performing subcellular fractionation. This methodology is established using Kaposi’s sarcoma-associated herpesvirus (KSHV) infection of human foreskin fibroblast (HFF) cells as a model. With KSHV and other herpesviruses alike, envelope glycoproteins have been widely reported to physically engage target cell surface receptors, such as integrins, in interactions leading to entry and subsequent infection. Results Subcellular fractionation was used to isolate early and late endosomes (EEs and LEs) by performing a series of centrifugations steps. Specifically, a centrifugation step post-homogenization was utilized to obtain the post-nuclear supernatant containing intact intracellular organelles in suspension. Successive fractionation via sucrose density gradient centrifugation was performed to isolate specific organelles including EEs and LEs. Intracellular KSHV trafficking was directly traced in the isolated endosomal fractions. Additionally, the subcellular fractionation approach demonstrates a key role for integrins in the endosomal trafficking of KSHV. The results obtained from fractionation studies corroborated those obtained by traditional imaging studies. Conclusions This study is the first of its kind to employ a sucrose flotation gradient assay to map intracellular KSHV trafficking in HFF cells. We are confident that such an approach will serve as a powerful tool to directly study intracellular trafficking of a virus, signaling events occurring on endosomal membranes, and dynamics of molecular events within endosomes that are crucial for uncoating and virus escape into the cytosol

HTLV-1 infection in solid organ transplant donors and recipients in Spain

Background: HTLV-1 infection is a neglected disease, despite infecting 10–15 million people worldwide and severe illnesses develop in 10% of carriers lifelong. Acknowledging a greater risk for developing HTLV-1 associated illnesses due to immunosuppression, screening is being widely considered in the transplantation setting. Herein, we report the experience with universal HTLV testing of donors and recipients of solid organ transplants in a survey conducted in Spain. Methods: All hospitals belonging to the Spanish HTLV network were invited to participate in the study. Briefly, HTLV antibody screening was performed retrospectively in all specimens collected from solid organ donors and recipients attended since the year 2008. Results: A total of 5751 individuals were tested for HTLV antibodies at 8 sites. Donors represented 2312 (42.2%), of whom 17 (0.3%) were living kidney donors. The remaining 3439 (59.8%) were recipients. Spaniards represented nearly 80%. Overall, 9 individuals (0.16%) were initially reactive for HTLV antibodies. Six were donors and 3 were recipients. Using confirmatory tests, HTLV-1 could be confirmed in only two donors, one Spaniard and another from Colombia. Both kidneys of the Spaniard were inadvertently transplanted. Subacute myelopathy developed within 1 year in one recipient. The second recipient seroconverted for HTLV-1 but the kidney had to be removed soon due to rejection. Immunosuppression was stopped and 3 years later the patient remains in dialysis but otherwise asymptomatic. Conclusion: The rate of HTLV-1 is low but not negligible in donors/recipients of solid organ transplants in Spain. Universal HTLV screening should be recommended in all donor and recipients of solid organ transplantation in Spain. Evidence is overwhelming for very high virus transmission and increased risk along with the rapid development of subacute myelopath