Self-powered flexible photodetectors based on Ag nanoparticle-loaded g-C3N4 nanosheets and PVDF hybrids: role of plasmonic and piezoelectric effects.

Here we demonstrate novel self-powered photodetection using silver (Ag) nanoparticle-loaded two-dimensional graphitic carbon nitride (g-C3N4) nanosheets triggered by poly-vinylidene fluoride (PVDF)-based flexible piezoelectric nanogenerators. A self-poled PVDF-based nanogenerator has been obtained upon exploiting pristine g-C3N4 nanosheets as a filler material within the PVDF matrix. The fabricated nanogenerator devices are found to be highly efficient in generating the maximum voltage of ∼2.3 V and maximum power ∼110 µWatt/cm2, upon finger tapping. Further, the integration of an additional layer of plasmonic Ag nanoparticle-loaded g-C3N4 nanosheets, has led to a significant enhancement of photoresponse. The hybrid plasmonic nanogenerator (with a strain of ∼0.021%) has resulted in self-powered photodetection with a photo-to-dark current ratio of ∼60, as compared to the unstrained device (∼2.0). In contrast to the usual behaviour (positive photoresponse), the exposure of an ultraviolet light lowers the output current indicating a negative photoresponse reported for the first time in such a system. The origin of such negative photoresponse has been attributed to the screening of piezopotential of PVDF by photogenerated carriers of g-C3N4 nanosheets. On the other hand, visible light-induced positive photoresponse has originated from the increment in the current, indicating the useful role of Ag nanoparticles in plasmon-induced hot electron transfer process.

The impact of an antibiotic coating on the artificial urinary sphincter infection rate.

PURPOSE: In April 2008 InhibiZone® antibiotic coated artificial urinary sphincters were introduced. The antibiotic coating significantly increased the cost of the device by an average of $1,300 per artificial urinary sphincter. To our knowledge, no clinical data to date support the theory that this antibiotic coating decreases the risk of artificial urinary sphincter infection. Therefore, we compared infection rates in our cases before and after the introduction of InhibiZone coated artificial urinary sphincters to determine whether the coating decreased the device infection rate. MATERIALS AND METHODS: We retrospectively reviewed the records of 426 consecutive patients in whom an artificial urinary sphincter was implanted by a single surgeon from January 2005 to June 2012. Patients were divided equally into 213 consecutive males who received an artificial urinary sphincter without the antibiotic coating from January 2005 to March 2008 and 213 consecutive males implanted with the antibiotic coated artificial urinary sphincter from April 2008 to June 2012. Demographics and infection rates were compared. RESULTS: Patient mean age, associated comorbidities and complexity were almost identical in the groups with and without the antibiotic coating, and infection rates were identical at 7 patients (3.3%) per group (p = 0.99). In the more complex patient subgroup with revision the antibiotic coating did not impact the infection rate. Infection developed in 2 of 50 patients (5%) with the antibiotic coated device and in 3 of 38 (6%) with the uncoated device (p = 0.42). CONCLUSIONS: The InhibiZone coating of the artificial urinary sphincters did not alter the infection rate in our study. The added cost of the antibiotic coated artificial urinary sphincters (total of approximately $276,000 more for all 213 coated devices) was of no benefit in our series. Based on this assessment, we will transition to using artificial urinary sphincters without InhibiZone in our practice.

Advances in tubeless percutaneous nephrolithotomy and patient selection: an update.

Percutaneous nephrolithotomy (PCNL) is the gold standard for the treatment of large renal calculi. Recently, modifications to the standard PCNL with nephrostomy tube placement have evolved, most notably the introduction of tubeless PCNL. Tubeless PCNL appears to decrease postoperative discomfort and shorten hospital stays, without increasing complication rates in the appropriately selected patient population. Urologists have attempted to expand the role of tubeless PCNL in more complex clinical scenarios, including pediatric and geriatric patients, and in stones complicated by multiple access tracts, renal anomalies or previous renal surgery. In an attempt to further improve outcomes following tubeless PCNL, adjunct interventions such as the use of hemostatic agents along the percutaneous access tract and local tract anesthetic have also been evaluated. We report the most recent published data over the past year, reviewing the employment and efficacy of tubeless PCNL, and discuss the selection of appropriate patients for this modified procedure.

Acute bilateral ureteral obstruction secondary to guaifenesin toxicity.

Several medications or their metabolites have been associated with urolithiasis, although overall they remain an infrequent cause of urolithiasis. Guaifenesin stones were originally reported as complexed with ephedrine, and subsequent reports have demonstrated pure guaifenesin stones, occurring after long term abuse. We report a case of a 23-year-old male who ingested a large, one time dose of guaifenesin, resulting in acute bilateral ureteral obstruction, which, to our knowledge, is the first such reported case in the literature.

A computational analysis of whole-genome expression data reveals chromosomal domains of gene expression.

Chromosome correlation maps display correlations between the expression patterns of genes on the same chromosome. Using these maps, we show here that adjacent pairs of genes, as well as nearby non-adjacent pairs of genes, show correlated expression independent of their orientation. We present specific examples of adjacent pairs with highly correlated expression patterns, in which the promoter of only one of the two genes contains an upstream activating sequence (UAS) known to be associated with that expression pattern. Finally, we show that genes with similar functions tend to occur in adjacent positions along the chromosomes. Our results suggest that, in certain chromosomal expression domains, an UAS can affect the transcription of genes that are not immediately downstream from it.

Staphylococcal septicaemia associated with peripheral neuropathy in three different clinical settings.

Among the various etiologies of peripheral neuropathy, S. aureus is a rare cause that is not even mentioned in standard textbooks. Here we like to report three clinical scenarios where patients with different manifestations of S. aureus infection developed peripheral neuropathy presenting as quadriparesis, which subsided gradually with control of infection and supportive care. No other known causes of peripheral neuropathy were present in these cases.

Electrochemical, surface morphological and computational evaluation on carbohydrazide Schiff bases as corrosion inhibitor for mild steel in acidic medium.

Anticorrosion and adsorption behaviour of synthesized carbohydrazide Schiff bases, namely (Z)-N'-(4-hydroxy-3-methoxybenzylidene)-6-methyl-2-oxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carbohydrazide(MBTC) and (Z)-N'-(3,4-dichlorobenzylidene)-6-methyl-2-oxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carbohydrazide (CBTC) was examined for mild steel (MS) in 15% HCl medium. The corrosion inhibition study was performed by using gravimetric, thermodynamic, electrochemical and theoretical studies including density functional theory (DFT), molecular dynamic simulation (MDS) and Monte Carlo simulations (MCS). The outcomes in terms of corrosion inhibition efficiency using electrochemical impedance spectroscopy (EIS) method at 303 K and 150 ppm concentration were 96.75% for MBTC and 95.14% for CBTC. Both inhibitors adsorbed on the MS surface through physical as well as chemical adsorption and followed the Langmuir isotherm. The mixed-type nature of both inhibitors was identified by polarization results. Surface analysis was done using FESEM, EDX, AFM and XPS studies and results showed that a protective layer of inhibitor molecules was developed over the surface of MS. The results of DFT, MCS and MDS are in accordance with experimental results obtained by weight loss and electrochemical methods.

On the equivalence of posterior inference based on retrospective and prospective likelihoods: application to a case-control study of colorectal cancer.

The paper develops a class of priors that leads to equivalent posterior inference for odds ratio parameters based on prospective and retrospective models for categorical response data. The results are applicable to both unmatched and matched case-control studies. The results hold for a general class of link functions for categorical response. The proposed method can accommodate multiple and possibly ordered disease states. The results are applied to the analysis of discrete subtypes in an ongoing case-control study of colorectal cancer. A simulation study illustrates the need for carefully considering prior choices in Bayesian analysis of data collected under retrospective design.

Young male with systemic lupus erythematosus presenting with sensorineural deafness with immune suppression induced miliary tuberculosis.

A 32 year male presented with deafness and other classical symptoms suggestive of SLE. Subsequent serological investigations confirmed the diagnosis. Renal biopsy showed the presence of SLE induced Grade V nephropathy. Patient was started on NIH protocol for lupus nephritis on which he was doing well. After two years, he presented with symptoms of miliary tuberculosis and was started on ATD. Subsequently, he developed ATD induced hepatotoxicity and had to be switched over to Inj. Streptomycin containing regimen. We thought to share this clinical experience, as we found it a challenge to manage tuberculosis in such a setting, where a fine balance had to be maintained between immunosuppression for SLE and therapy of TB, and an ototoxic drug had to be used in a patient with deafness induced by SLE.

Aqueous Mg-Ion Supercapacitor and Bi-Functional Electrocatalyst Based on MgTiO3 Nanoparticles.

Supercapacitor and hydrogen-based fuel cells are cheap and environmental-friendly next-generation energy storage devices that are intended to replace Lithium-ion batteries. Metal oxide nanostructures having perovskite crystal structure have been found to exhibit unique electrochemical properties owing to its unique electronic band structure and multiple redox-active ions. Herein, MgTiO3 nanoparticles (MTO-1) were synthesized by wet-chemical sol-gel technique with an average particle size of 50-55 nm, which exhibited superior supercapacitor performance of capacitance (C) = 25 F/g (at 0.25 A/g), energy density (ED) = 17 Wh/kg, power density (PD) = 275 W/kg and 82.41% capacitance retention (after 1000 cycles). Aqueous 1 M Mg(ClO4)2 solution was used as the electrolyte. MTO-1 revealed an overpotential () = 1.329 V and Tafel slope (b) = 374 mV/dec towards Oxygen Evolution Reaction (OER) electrocatalyst and exhibited = 0.914 V and b = 301.4 mV/dec towards Hydrogen Evolution Reaction (HER) electrocatalyst, both in presence of alkaline 1 M KOH solution, making these MgTiO3 nanoparticles very promising for potential use in various technologically important electrochemical applications.

Molten Salt Synthesized MgNiO2 Micro/Nano-Particles for High Energy Density Supercapacitor and Electrocatalyst for Hydrogen Evolution Reaction in Alkaline Medium.

In recent years, solid solutions have shown promising results as functional materials for different applications. These materials have tunable physiochemical properties and electronic properties, and are being intensively studied for next generation electrochemical charge storage as well as noble metal free low cost electrocatalyts. In the present work, Magnesium Nickel Oxide (MgNiO2) solid solution is prepared by molten salt synthesis. MgNiO2 particles having octahedron shaped morphology with size of 550 nm with an agglomerative behavior was observed through morphological studies. Raman studies revealed presence of three two-phonon modes as well as two one-phonon modes, which confirm the phase purity of MgNiO2 sample. MgNiO2 particles behaved as a promising supercapacitor candidate by exhibiting a large specific capacitance of 76 F/g. It also revealed electrochemical stability over an expansive potential range under the presence of 0.5 mol L-1Sodium Sulfate (Na2SO4) electrolyte, having a high energy density of nearly 51 Wh/kg with a power density of nearly 825 w/kg. Further, MgNiO2 particle showed improved electrocatalytic potential towards Hydrogen Evolution Reaction (HER) in 1 mol L-1 Potassium Hydroxide (KOH) alkaline medium, by demonstrating an overpotential of 0.636 V with a Tafel slope of 0.22205 v/dec. Based on these observed promising results, it can be conclusively inferred that MgNiO2 solid solution is a potential candidate for environmental friendly high voltage supercapacitor and HER electrocatalyst applications.

Efficient isolation and propagation of human immunodeficiency virus on recombinant colony-stimulating factor 1-treated monocytes.

Monocytes were maintained in tissue culture for greater than 3 mo in media supplemented with rCSF-1. These cultures provided susceptible target cells for isolation and propagation of virus from PBMC of HIV-infected patients. HIV isolated into monocytes readily infected other rCSF-1-treated monocytes but only inefficiently infected PHA-stimulated lymphoblasts. Similarly, laboratory HIV strains passaged in T cell lines or virus isolated from patients' leukocytes into PHA-stimulated lymphoblasts inefficiently infected rCSF-1-treated monocytes. Persistent, low-level virion production was detected in macrophage culture fluids by reverse transcriptase activity or HIV antigen capture through 6-7 wk. Marked changes in cell morphology with cell death, syncytia, and giant cell formation were observed in monocyte cultures 2 wk after infection, but at 4-6 wk, all cells appeared morphologically normal. However, the frequency of infected cells in these cultures at 6 wk was 60-90% as quantified by in situ hybridization with HIV RNA probes or by immunofluorescence with AIDS patients' sera. Ultrastructural analysis by EM also showed a high frequency of infected cells; virtually all HIV budded into and accumulated within cytoplasmic vacuoles and virus particles were only infrequently associated with the plasma membrane. Retention of virus within macrophages and the macrophage tropism of HIV variants may explain mechanisms of both virus persistence and dissemination during disease.

SK2 potassium channel overexpression in basolateral amygdala reduces anxiety, stress-induced corticosterone secretion and dendritic arborization.

The basolateral amygdala is critical for generation of anxiety. In addition, exposure to both stress and glucocorticoids induces anxiety. Demonstrated ability of the amygdala to change in response to stress and glucocorticoids could thus be important therapeutic target for anxiety management. Several studies have reported a relationship between anxiety and dendritic arborization of the amygdaloid neurons. In this study we employed a gene therapeutic approach to reduce anxiety and dendritic arborization of the amygdala neurons. Specifically, we overexpressed SK2 potassium channel in the basolateral amygdala using a herpes simplex viral system. Our choice of therapeutic cargo was guided by the indications that activation of the amygdala might underlie anxiety and that SK2 could reduce neuronal activation by exerting inhibitory influence on action potentials. We report that SK2 overexpression reduced anxiety and stress-induced corticosterone secretion at a systemic level. SK2 overexpression also reduced dendritic arborization of the amygdala neurons. Hence, SK2 is a potential gene therapy candidate molecule that can be used against stress-related neuropsychiatric disorders such as anxiety.

Efficacy of Second Molar to Achieve Anchorage Control in Maximum Anchorage Cases.

BACKGROUND: The aim of the study was to assess the efficacy of inclusion of second molar in treatment at the outset to reinforce anchorage. METHODS: A comparative study comprising of 30 maximum anchorage cases to quantify anchorage loss in two situations was undertaken. Group I consisted of cases in which only first molars were banded and Group II consisted of cases where both first and second molars were banded. A total of seven landmarks were marked and six measurements were recorded on to the pre-treatment and post-treatment lateral cephalogram. RESULT: The difference in pre-treatment and post-treatment values of all the variables were statistically significant (p<0.05) except maxillary central incisor vertical movement (U1 VER), implying a significant post-treatment change. Thus in both the treatment approaches U6 and U1 showed a considerable amount of movement in horizontal and vertical direction and there was rotation which brought about change in angular values. CONCLUSION: The study has successfully quantified the anchorage loss and brought out the advantages of including second molar in treatment at the outset. Not only the anchorage loss is minimized but inclusion of second molar also helps to maximize incisor retraction and helps control angular movement of molar and incisor. Extra time required for second molar banding is well spent, as the benefits are overwhelming.

Two-dimensional graphitic carbon nitride nanosheets: a novel platform for flexible, robust and optically active triboelectric nanogenerators.

We report on the characteristics of mechanically flexible, stable and photoactive triboelectric nanogenerators based on two-dimensional graphitic carbon nitride (g-C3N4) nanosheets. The performance of nanogenerator devices has been studied with varying frictional surfaces (such as polypropylene, aluminium oxide, Teflon and polyethylene terephthalate). Energy band diagrams have been used to explain the mechanism of triboelectric charge transfer in pristine and doped g-C3N4, with the former showing better characteristics. An optimized device has been found to be responsive to external stimuli to generate an output voltage of 10 V upon simple biomechanical impulses. To demonstrate the efficacy for practical applications of g-C3N4-based triboelectric nanogenerators, output voltages have been recorded for different common activities like walking, water showering, using as a writing/drawing pad, etc. Repetitive finger tapping on a device could charge a capacitor to as high as 55 V within ∼50 s, while that under UV illumination is found to be much faster (∼14 s) due to photoinduced carrier generations in g-C3N4. The exhibition of a superior photoresponsivity of ∼117 V W-1 under UV illumination demonstrates the dual functionality of g-C3N4-based triboelectric devices as a nanogenerator as well as an active flexible photosensor, which is hitherto unreported. Excellent mechanical flexibility, stability and photoinduced enhancement of output characteristics make g-C3N4 an attractive candidate for nanogenerator devices for future applications.

Ca2+ and Ca2+-activated K+ currents in mammalian gastric smooth muscle cells.

Inward movement of calcium through voltage-dependent channels in muscle is thought to initiate the action potential and trigger contraction. Calcium-activated potassium channels carry large outward potassium currents that may be responsible for membrane repolarization. Calcium and calcium-activated potassium currents were identified in enzymatically isolated mammalian gastric myocytes. These currents were blocked by cadmium and nifedipine but were not substantially affected by diltiazem or D600. No evidence for a tetrodotoxin-sensitive sodium current or an inwardly rectifying potassium current was found.

Utilization of HIV point-of-care testing clinics in general practice and genitourinary medicine services in south-east London.

We compared the utilization of HIV point-of-care testing (POCT) clinics in a general practice and a genitourinary (GU) medicine service. Retrospective case-note review of patients attending the general practice HIV POCT clinic from February 2005 to July 2007 was undertaken. Those attending the GU medicine service over the same period were used as a comparator group. HIV POCT clinics in general practice when compared with GU medicine services were significantly more likely to be utilized by those of Black ethnicity (Black African 61/370 [16.5%] vs. 107/1231 [8.7%], P < 0.001; Black Caribbean 19/370 [5.1%] vs. 11/1231 [0.9%], P < 0.001 and Black Other 20/370 [5.4%] vs. 26/1231 [2.1%], P = 0.001, respectively). Fewer men who have sex with men attended for HIV POCT in general practice than in GU medicine; 82/238 (34.5%) vs. 337/816 (41.3%), P = 0.058. We have demonstrated that HIV POCT clinics in primary care and GU medicine attract different 'at-risk' groups and provide increased opportunity for testing.

Effect of route of introduction and host cultivar on the colonization, internalization, and movement of the human pathogen Escherichia coli O157:H7 in spinach.

Human pathogens can contaminate leafy produce in the field by various routes. We hypothesized that interactions between Escherichia coli O157:H7 and spinach are influenced by the route of introduction and the leaf microenvironment. E. coli O157:H7 labeled with green fluorescent protein was dropped onto spinach leaf surfaces, simulating bacteria-laden raindrops or sprinkler irrigation, and survived on the phylloplane for at least 14 days, with increasing titers and areas of colonization over time. The same strains placed into the rhizosphere by soil infiltration remained detectable on very few plants and in low numbers (10(2) to 10(6) CFU/g fresh tissue) that decreased over time. Stem puncture inoculations, simulating natural wounding, rarely resulted in colonization or multiplication. Bacteria forced into the leaf interior survived for at least 14 days in intercellular spaces but did not translocate or multiply. Three spinach cultivars with different leaf surface morphologies were compared for colonization by E. coli O157:H7 introduced by leaf drop or soil drench. After 2 weeks, cv. Bordeaux hosted very few bacteria. More bacteria were seen on cv. Space and were dispersed over an area of up to 0.3 mm2. The highest bacterial numbers were observed on cv. Tyee but were dispersed only up to 0.15 mm2, suggesting that cv. Tyee may provide protected niches or more nutrients or may promote stronger bacterial adherence. These findings suggest that the spinach phylloplane is a supportive niche for E. coli O157:H7, but no conclusive evidence was found for natural entry into the plant interior. The results are relevant for interventions aimed at minimizing produce contamination by human pathogens.

Polony analysis of gene expression in ES cells and blastocysts.

Expression profiling of stem cells is challenging due to their small numbers and heterogeneity. The PCR colony (polony) approach has theoretical advantages as an assay for stem cells but has not been applied to small numbers of cells. An assay has been developed that is sensitive enough to detect mRNAs from small numbers of ES cells and from fractions of a single mouse blastocyst. Genes assayed include Oct3, Rex1, Nanog, Cdx2 and GLUT-1. The assay is highly sensitive so that multiple mRNAs from a single blastocyst were easily detected in the same assay. In its present version, the assay is an attractive alternative to conventional RT-PCR for profiling small populations of stem cells. The assay is also amenable to improvements that will increase its sensitivity and ability to analyze many cDNAs simultaneously.

Acute undifferentiated human diarrhea in the tropics. II. Alterations in intestinal fluid and electrolyte movements.

The nature and magnitude of fluid and electrolyte loss into the small intestine were defined by the marker perfusion technique in patients with acute undifferentiated diarrhea (AUD) in the tropics. The patients were divided into two groups according to their small bowel bacteriologic findings, namely those with a predominant Escherichia coli flora and those with a mixed flora. 11 normal subjects served as controls. Net jejunal fluid secretion occurred into the lumen in four of seven patients with E. coli flora and three of seven with a mixed flora. The magnitude of secretion in the jejunum was greater in the E. coli flora patients than in those with a mixed flora. Four E. coli patients and one mixed flora patient had net fluid secretion in the ileum, although the magnitude of secretion in this area was less than in the jejunum. Intestinal fluid had higher bicarbonate concentration in the ileum than in the jejunum but was isotonic in both regions. It resembled in composition fluid from the same region of intestine in normal individuals. Recovery of normal fluid and electrolyte absorptive function was usually complete in both jejunum and ileum by 6-8 days after onset of the disease. Increase in unidirectional flux rates for H(3)O and (24)Na occurred in acute E. coli flora diarrhea and returned to normal levels in recovery: increase in J(beta) (plasma to lumen flux) primarily accounted for the increase in fluid loss. Intestinal biopsy revealed no alterations in villous architecture.A relationship between small bowel fluid production and the presence of toxigenic strains of E. coli within the small bowel has been found for E. coli flora patients. In many respects this disease resembles acute cholera. The mixed flora group represents a less defined entity which requires further study.