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.

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.

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.

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.

A bifunctional chiral [2]catenane based on 1,1'-binaphthyl-phosphates.

A novel [2]catenane was synthesised by ring-closing metathesis from a Ca-bisphosphate template. The resulting interlocked structure features two chiral 1,1'-binaphthyl-phosphates, leading to a bifunctional catenane structure. Initial binding studies point at the applicability of such mechanically interlocked bisphosphates as artificial receptors for dicationic guest molecules.

Short environmental enrichment in adulthood reverses anxiety and basolateral amygdala hypertrophy induced by maternal separation.

Maternal separation during early childhood results in greater sensitivity to stressors later in adult life. This is reflected as greater propensity to develop stress-related disorders in humans and animal models, including anxiety and depression. Environmental enrichment (EE) reverses some of the damaging effects of maternal separation in rodent models when provided during peripubescent life, temporally proximal to the separation. It is presently unknown if EE provided outside this critical window can still rescue separation-induced anxiety and neural plasticity. In this report we use a rat model to demonstrate that a single short episode of EE in adulthood reduced anxiety-like behaviour in maternally separated rats. We further show that maternal separation resulted in hypertrophy of dendrites and increase in spine density of basolateral amygdala neurons in adulthood, long after initial stress treatment. This is congruent with prior observations showing centrality of basolateral amygdala hypertrophy in anxiety induced by stress during adulthood. In line with the ability of the adult enrichment to rescue stress-induced anxiety, we show that enrichment renormalized stress-induced structural expansion of the amygdala neurons. These observations argue that behavioural plasticity induced by early adversity can be rescued by environmental interventions much later in life, likely mediated by ameliorating effects of enrichment on basolateral amygdala plasticity.

Aqueous extract of Costus arabicus inhibits calcium oxalate crystal growth and adhesion to renal epithelial cells.

Costus arabicus L. (C. arabicus) is a plant used in Brazilian folk medicine to treat urolithiasis; however, its mechanism of action is unclear. The interaction between calcium oxalate (CaOx) crystals and the renal epithelium is important in calculogenesis, and compounds that modulate this process represent candidate therapeutic agents for stone prevention. Therefore, we assessed the inhibitory activity of C. arabicus on CaOx crystallization and the interaction of CaOx crystals with the renal epithelium. A seeded CaOx monohydrate (COM) crystallization system was used to study the effect of C. arabicus on crystal growth. Madin Darby canine kidney (MDCK) cells were used to study [(14)C] COM crystal adhesion in the presence and absence of an aqueous extract of C. arabicus. Cytotoxicity was assessed using a tetrazolium (MTS) cell proliferation assay. Aqueous extracts of C. arabicus decreased crystal growth in a concentration-dependent fashion. Precoating crystals with C. arabicus extract prevented their adhesion to MDCK cells, while pretreating cells did not show any effect. The extract was non-cytotoxic in concentrations of at least 1 mg/ml, which is likely above concentrations achievable in the urine following oral ingestion and excretion. No inhibitory activity was found in hexane, methyl chloride, n-butanol and ethyl acetate fractions of an ethanol extract of the herb. An aqueous extract of C. arabicus may disrupt calculogenesis by interacting with CaOx crystal surfaces. Activity was present in the aqueous extract; therefore, this agent may be bioavailable when administered orally. Fractionation results suggest that the active agent might be a polar polysaccharide. Further identification and characterization along these lines may be warranted.

Secondarily infected nonstruvite urolithiasis: a prospective evaluation.

OBJECTIVE: To characterize patients who form nonstruvite stones associated with infection (secondarily infected calculi), and to define the bacteria associated with these. MATERIALS AND METHODS: Patients undergoing percutaneous nephrolithotomy were prospectively recruited. Medical records were reviewed, and stones were analyzed using micro computed tomography and infrared spectroscopy. A fragment of each stone was sent for bacterial culture. Patients were categorized by stone culture results (SC ±) and the presence of struvite (ST ±). The Fisher exact test was used for comparison of proportion. Sterility of intraoperative SC was established with independently collected controls. RESULTS: In total, 125 patients were enrolled: 24 SC+/ST-, 19 SC+/ST+, and 82 SC-/ST-. Proportions of patients with prior urologic surgery, diabetes, and immunodeficiency were similar between groups. Patients with neurogenic bladder were more likely to have SC+/ST+ stones or SC+/ST- stones than SC-/ST- stones (26% vs 8% vs 0%, respectively; P <.01). Among patients with metabolic evaluations, hypocitraturia was found in 31.6% (6 of 19) SC+/ST- patients, 46.7% (7 of 15) SC+/ST+ patients, and 26.0% (19 of 73) of SC-/ST- patients (P = .28). Approximately 40% of cultured organisms in the secondarily infected calculi possessed urease and another 40% citrate lyase activities. CONCLUSION: Secondarily infected stones were detected in approximately 20% of this surgical cohort and may be more common than previously appreciated. Neurogenic bladder appeared to predispose patients to either struvite or secondarily infected stones. The role of bacterial infection in stone formation is unclear but may include alteration of urinary components, acting as a nidus for crystallization, or inducing inflammation.

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.

The utilization of opiates in pain management: use or abuse.

BACKGROUND: Despite governmental regulations, opiate medications continue to be abused in some populations. Some clinicians have advocated non-opioid therapy for pain patients that suffer from non-malignant conditions; while others have suggested that chronic benign pain conditions may successfully be managed with opiates in non-escalating dosages. AIM: The aim of this paper was to review the literature regarding opiate utilization in the acute and chronic pain population. DESIGN: Review. SETTING: Europe and United States. POPULATION: Acute and chronic adult pain patients. METHODS: A computer-aided search of several databases--MEDLINE (1966 to July 2012); EMBASE (Elsevier BV, Amsterdam, the Netherlands), 1982 to present; CINAHL (Cumulative Index to Nursing and Allied Health Literature, EBSCO Industries, Glendale, CA), 1982 to July 2012; and all EBM (Evidence-Based Medicine) reviews was performed. The search terms were pain, opioid, opiate and narcotic. RESULTS: It is generally accepted that WHO step III opioids are indicated and appropriate in malignant conditions, however the utilization of opiates in non-malignant chronic conditions remains controversial. CONCLUSION: Limited data does support the utilization of non-escalating dosages of opiates in patients that are closely monitored in non-malignant conditions. Education in opiate utilization and pain management is insufficient in its current form. CLINICAL REHABILITATION IMPACT: Studies demonstrating functional improvements with the utilization of opiate medications are also lacking. Physical Medicine and Rehabilitation researchers therefore have an ideal opportunity to positively influence education, regulation and patient care in this field.

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.

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.

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.

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.

Hla-a and hla-B alleles associated in psoriasis patients from mumbai, Western India.

BACKGROUND: Psoriasis, a common autoimmune disorder characterized by T cell-mediated keratinocyte hyperproliferation, is known to be associated with the presence of certain specific Human Leukocyte Antigen (HLA) alleles. AIM: To evaluate distribution of HLA-A and HLA-B alleles and hence identify the susceptible allele of psoriasis from patients in Western India. MATERIALS AND METHODS: The study design included 84 psoriasis patients and 291 normal individuals as controls from same geographical region. HLA-A and HLA-B typing was done using Serology typing. Standard statistical analysis was followed to identify the odds ratio (OR), allele frequencies, and significant P value using Graphpad software. RESULTS: The study revealed significant increase in frequencies of HLA-A2 (OR-3.976, P<0.0001), B8 (OR-5.647, P<0.0001), B17 (OR-5.452, P<0.0001), and B44 (OR-50.460, P<0.0001), when compared with controls. Furthermore, the frequencies of HLA-A28 (OR-0.074, P=0.0024), B5 (OR-0.059, P<0.0001), B12 (OR-0.051, P=0.0002), and B15 (OR-0.237, P=0.0230) were significantly decreased in psoriasis patients. CONCLUSION: This study shows the strong association of HLA-A2, B8, and B17 antigens with psoriasis conferring susceptibility to psoriasis patients from Western India, while the antigens HLA-A28, B5, and B12 show strong negative association with the disease.

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.

Prevalence of ponticulus posticus in Indian orthodontic patients.

OBJECTIVES: The purpose of this study was to investigate the prevalence of complete ponticulus posticus in Indian orthodontic patients. METHODS: The presence and types of ponticuli posticus were investigated on 858 lateral cephalograms. RESULTS: Complete ponticulus posticus was found in 4.3% of the subjects studied with a male (5.33%) predominance over female in the population (3.76%). CONCLUSIONS: Ponticulus posticus is not a rare anomaly and the patient must be told of the implications and importance of detecting ponticulus posticus on a lateral cephalogram. This information can prove beneficial for the diagnosis of head and neck symptoms later.