Renormalization group study of the Kondo problem at a junction of several Luttinger wires

We study a system consisting of a junction of N quantum wires, where the junction is characterized by a scalar S-matrix, and an impurity spin is coupled to the electrons close to the junction. The wires are modeled as weakly interacting Tomonaga-Luttinger liquids. We derive the renormalization group equations for the Kondo couplings of the spin to the electronic modes on different wires, and analyze the renormalization group flows and fixed points for different values of the initial Kondo couplings and of the junction S-matrix (such as the decoupled S-matrix and the Griffiths S-matrix). We generally find that the Kondo couplings flow towards large and antiferromagnetic values in one of two possible ways. For the Griffiths S-matrix, we study one of the strong coupling flows by a perturbative expansion in the inverse of the Kondo coupling; we find that at large distances, the system approaches the ferromagnetic fixed point of the decoupled S-matrix. For the decoupled S-matrix with antiferromagnetic Kondo couplings and weak inter-electron interactions, the flows are to one of two strong coupling fixed points in which all the channels are strongly coupled to each other through the impurity spin. But strong inter-electron interactions, with K_\rho < N/(N+2), stabilize a multi-channel fixed point in which the coupling between different channels goes to zero. We have also studied the temperature dependence of the conductance at the decoupled and Griffiths S-matrices.Comment: Revtex4, 16 pages including 6 figure

Spontaneous urinary bladder perforation as a cause of recurrent, progressive ascites with multiorgan dysfunction syndrome

Spontaneous rupture of the urinary bladder wall is a rare complication that may lead to intraperitoneal accumulation of urine and is mistaken for ascites from other causes. This often leads to repeated and inconclusive diagnostic tests. Here, we report the case of a 60-year-old female, with a past history of cervical cancer, who presented with recurrent episodes of pain abdomen and breathlessness over 1 year period. She was hospitalized multiple times and found to have ascites. Ultrasound and computed tomography scan of the abdomen along with an ascitic fluid analysis were done at each admission, which were inconclusive as to the cause of the ascites. A diagnostic laparoscopy to rule out peritoneal metastases showed perforation of the urinary bladder wall with intraperitoneal urine leakage. Bladder wall repair was done the following which the patient recovered uneventfully

Bacterial Endo-Symbiont Inhabiting Tridax procumbens L. and Their Antimicrobial Potential

Bacterial symbionts inhabiting Tridax procumbens L. were screened for antimicrobial potential with the aim to isolate potent bacteria bearing significant activity against test pathogens. The selected isolate was subjected to large scale fermentation to extract antimicrobial metabolite. The organic phase was reduced under vacuum pressure and crude ethyl acetate extract (10 mg/mL) was evaluated for antimicrobial activity against panel of test pathogens. The antibacterial activity was measured as a zone of inhibition and compared with standard antibiotics, gentamicin and tetracycline. Similarly, antifungal activity was compared with miconazole and bavistin. Significant activity was conferred against Shigella flexneri (MTCC 731) with 27±1.5 mm zone across the disc. Partially, purification of antimicrobial metabolite with TLC-bioautography and HPLC resulted in active fraction bearing activity at Rf 0.65 and eluting between 4 and 5 retention times. The obtained results are promising enough for future purification and characterization of antimicrobial metabolite. Thus, the study attributes to the growing knowledge on endophytes as one of the rich sources of antimicrobial potentials

Repeat treatment with rifaximin is safe and effective in patients with diarrhea-predominant irritable bowel syndrome

Background & AimsFew treatments have demonstrated efficacy and safety for diarrhea-predominant irritable bowel syndrome (IBS-D). A phase 3, randomized, double-blind, placebo-controlled trial was performed to evaluate the safety and efficacy of repeat treatment with the nonsystemic antibiotic rifaximin.MethodsThe trial included adults with IBS-D, mean abdominal pain and bloating scores of 3 or more, and loose stool, located at 270 centers in the United States and Europe from February 2012 through June 2014. Those responding to a 2-week course of open-label rifaximin 550 mg 3 times daily, who then relapsed during an observation phase (up to 18 weeks), were randomly assigned to groups given repeat treatments of rifaximin 550 mg or placebo 3 times daily for 2 weeks. The primary end point was percentage of responders after first repeat treatment, defined as a decrease in abdominal pain of ≥30% from baseline and a decrease in frequency of loose stools of ≥50% from baseline, for 2 or more weeks during a 4-week post-treatment period.ResultsOf 1074 patients (44.1%) who responded to open-label rifaximin, 382 (35.6%) did not relapse and 692 (64.4%) did; of these, 636 were randomly assigned to receive repeat treatment with rifaximin (n = 328) or placebo (n = 308). The percentage of responders was significantly greater with rifaximin than placebo (38.1% vs 31.5%; P = .03). The percentage of responders for abdominal pain (50.6% vs 42.2%; P = .018) was significantly greater with rifaximin than placebo, but not stool consistency (51.8% vs 50.0%; P = .42). Significant improvements were also noted for prevention of recurrence, durable response, and bowel movement urgency. Adverse event rates were low and similar between groups.ConclusionsIn a phase 3 study of patients with relapsing symptoms of IBS-D, repeat rifaximin treatment was efficacious and well tolerated. ClinicalTrials.gov ID: NCT01543178

Ficus racemosa Stem Bark Extract: A Potent Antioxidant and a Probable Natural Radioprotector

Ethanol extract (FRE) and water extract (FRW) of Ficus racemosa (family: Moraceae) were subjected to free radical scavenging both by steady state and time resolved methods such as nanosecond pulse radiolysis and stopped-flow spectrophotometric analyses. FRE exhibited significantly higher steady state antioxidant activity than FRW. FRE exhibited concentration dependent DPPH, ABTS•−, hydroxyl radical and superoxide radical scavenging and inhibition of lipid peroxidation with IC50 comparable with tested standard compounds. In vitro radioprotective potential of FRE was studied using micronucleus assay in irradiated Chinese hamster lung fibroblast cells (V79). Pretreatment with different doses of FRE 1h prior to 2 Gy γ-radiation resulted in a significant (P < 0.001) decrease in the percentage of micronucleated binuclear V79 cells. Maximum radioprotection was observed at 20 μg/ml of FRE. The radioprotection was found to be significant (P < 0.01) when cells were treated with optimum dose of FRE (20 μg/ml) 1 h prior to 0.5, 1, 2, 3 and 4 Gy γ-irradiation compared to the respective radiation controls. The cytokinesis-block proliferative index indicated that FRE does not alter radiation induced cell cycle delay. Based on all these results we conclude that the ethanol extract of F. racemosa acts as a potent antioxidant and a probable radioprotector

Converting a paper proforma template to a user friendly electronic database to collect traumatic brain injury data

A structured reporting system which is based on a uniform template will permit uniform data collection and future statistics and will facilitate and validate independent or comparative audit of performance and quality of care. The successful establishment of a multi-center registry depends on the development of a concise data entry form, data entry system and data analysis to continuously maintain the registry. In the first phase we introduced the paper data collection form, in second phase this data form was converted to an electronic interface. In this second phase of the study the paper proforma which was developed in the first phase was converted into an electronic database by using the FileMaker Pro 13 Advanced®. The FileMaker Pro 13 Advanced® is capable to store the data, provides user friendly interface to enter data and can be converted the standalone runtime program to install in any other computer system. The next step is to explore the possibility whether it would be feasible to use this as a multi-center traumatic brain injury registry

Nanocrystalline Pentaerythritoltetranitrate using Sol-Gel Process

The secondary explosives developed with reduced particle size tend to be more insensitive for mechanical stimuli and may release energy with faster rate and gaining more importance nowadays. Therefore, aiming to reduce the particle size of one of the popular explosives, viz., pentaerythritoltetranitrate (PETN) to the nanometer range, a method for preparation of nanocrystalline PETN in the silica (SiO2) gel matrix using sol-gel process has been demonstrated. The PETN-SiO2 xerogels were prepared containing PETN content ranging from 50 per cent to 90 per cent (w/w) and the xerogels were characterised using different techniques. An exothermic peak at around 185 oC preceded by an endotherm in thermal analysis accompanied with weight loss in the temperature range from 150 oC to 200 oC   for the xerogel confirmed the presence of PETN in xerogel. Infrared spectra of xerogels showed peaks at around 1285 cm-1 and 1700 cm-1 assigned to O-NO2 and C-O bond representing PETN. Small angle x-ray scattering measurements on xerogels indicated that PETN entered in the pores of silica matrix. Transmission electron microscopy revealed that cystalline PETN    with particle size of around 15 nm dispersed in silica xerogel. The specific surface area for the PETN-SiO2 (90:10) xerogels was found to be 75 m2/g.Defence Science Journal, 2011, 61(6), pp.534-539, DOI:http://dx.doi.org/10.14429/dsj.61.59

Developing a traumatic brain injury registry: lessons learned from difficulties

Aim: The aim of present article is to share our experiences and lessons learned from a pilot study which was conducted to collect data to serve as a model in establishing a multi-center registry on traumatic brain injury patients.Methods: The present study was conducted from December 2013 to June 2014 in the Department of Neurosurgery and Department of Accident and Emergency Medicine. All patients with the diagnosis of traumatic brain injury (as per the criteria laid by International Classification of Disease injury codes ICD 10) were enrolled in the study. Variables were identified as per the international norms and the data points were selected which included demographic details, pre-hospital characteristics, clinical details in emergency room, injury details, course during hospital stay, treatment and disposition. The data were categorized into master data, data related to pre-hospital events including pre-hospital care, data related to emergency room care offered in the emergency department, data related to hospital stay and patient course, outcome and follow up.Results: A total of 231 patients were admitted with the diagnosis of traumatic brain injury. There were 79.1% male and 20.5% female patients. Mean age was 37.19 years (SD±17.02 years, range 4-87 years). Mean hospital stay was 3.66 days (SD±4.46 days, range-1-21 days). Data were collected daily for all the admitted patients on previous day fulfilling the inclusion criteria. The Proforma was easy to comprehend and it was easy to fill.Conclusion: We found that a well-designed Proforma based under supervision data collection in a relatively low volume trauma center. We found that a well-designed Proforma based under supervision data collection in a relatively low volume trauma center and at regular intervals can be cost-effective which can be managed by personnel with basic training

Biomimetic synthesis of silver nanoparticles using endosymbiotic bacterium inhabiting euphorbia hirtal. And their bactericidal potential

The present investigation aims to evaluate biomimetic synthesis of silver nanoparticles using endophytic bacterium EH 419 inhabiting Euphorbia hirta L. The synthesized nanoparticles were initially confirmed with change in color from the reaction mixture to brown indicating the synthesis of nanoparticles. Further confirmation was achieved with the characteristic absorption peak at 440 nm using UV-Visible spectroscopy. The synthesized silver nanoparticles were subjected to biophysical characterization using hyphenated techniques. The possible role of biomolecules in mediating the synthesis was depicted with FTIR analysis. Further crystalline nature of synthesized nanoparticles was confirmed using X-ray diffraction (XRD) with prominent diffraction peaks at 2θ which can be indexed to the (111), (200), (220), and (311) reflections of face centered cubic structure (fcc) of metallic silver. Transmission electron microscopy (TEM) revealed morphological characteristics of synthesized silver nanoparticles to be polydisperse in nature with size ranging from 10 to 60 nm and different morphological characteristics such as spherical, oval, hexagonal, and cubic shapes. Further silver nanoparticles exhibited bactericidal activity against panel of significant pathogenic bacteria among which Pseudomonas aeruginosa was most sensitive compared to other pathogens. To the best of our knowledge, present study forms first report of bacterial endophyte inhabiting Euphorbia hirta L. in mediating synthesizing silver nanoparticle

An avian influenza A(H11N1) virus from a wild aquatic bird revealing a unique Eurasian-American genetic reassortment

Influenza surveillance in different wild bird populations is critical for understanding the persistence, transmission and evolution of these viruses. Avian influenza (AI) surveillance was undertaken in wild migratory and resident birds during the period 2007–2008, in view of the outbreaks of highly pathogenic AI (HPAI) H5N1 in poultry in India since 2006. In this study, we present the whole genome sequence data along with the genetic and virological characterization of an Influenza A(H11N1) virus isolated from wild aquatic bird for the first time from India. The virus was low pathogenicity and phylogenetic analysis revealed that it was distinct from reported H11N1 viruses. The hemagglutinin (HA) gene showed maximum similarity with A/semipalmatedsandpiper/Delaware/2109/2000 (H11N6) and A/shorebird/Delaware/236/2003(H11N9) while the neuraminidase (NA) gene showed maximum similarity with A/duck/Mongolia/540/2001(H1N1). The virus thus possessed an HA gene of the American lineage. The NA and other six genes were of the Eurasian lineage and showed closer relatedness to non-H11 viruses. Such a genetic reassortment is unique and interesting, though the pathways leading to its emergence and its future persistence in the avian reservoir is yet to be fully established