Multilayered and Chemiresistive Thin and Thick Film Gas Sensors for Air Quality Monitoring

Selective detection of gases such as nitrogen dioxide (NO2), carbon monoxide (CO), carbon dioxide (CO2), and various volatile organic components (VOCs) is necessary for air quality monitoring. Detection of hydrogen (H2) is equally important as it is a flammable gas and poses serious threat of explosion when exposed to oxygen gas. We have studied the sensing characteristics of these gases using thin film deposited by chemical solution deposition as well as relatively thicker films deposited by atmospheric plasma spray (APS) process. The chapter starts with the sensing mechanism of chemiresistive sensors followed by the definition of gas sensing parameters. Subsequently, we have demonstrated selective NO2 sensing characteristics of zinc oxide-graphene (ZnO-G) multilayered thin film followed by CO and H2 sensing characteristics of ZnO thin film and SnO2 thick film. Cross-sensitivity among CO and H2 gases has been addressed through the analysis of conductance transients with the determination of activation energy, Ea, and heat of adsorption, Q. The concepts of reversible and irreversible sensing have also been discussed in relation to CO and H2 gases. CO2 sensing characteristics of LaFe0.8Co0.2O3 (LFCO)-ZnO thin film have been elucidated. Interference from CO has been addressed with principal component analyses and the ascertaining of Ea and Q values. Additionally, the variation of response with temperature for each gas was simulated to determine distinct parameters for the individual gases. Further, VOC sensing characteristics of copper oxide (CuO) thin film and WO3-SnO2 thick film were investigated. Principal component analysis was performed to discriminate the gases in CuO thin film. The interaction of WO3-SnO2 thick film with various VOCs was found to obey the Freundlich adsorption isotherm based on which Ea and Q values were determined

Correlation of serum androgen and gonadotropin with anti-mullerian hormone in polycystic ovarian syndrome in Eastern Indian population

Background: Ovarian steroidogenesis requires gonadotropin stimulation, Luteinizing Hormone (LH) is a key factor in the hyperandrogenaemia of the polycystic ovary syndrome. Progesterone is the primary regulator of Gonadotropin-Releasing Hormone (GnRH) pulse frequency; however, in the polycystic ovary syndrome, the GnRH pulse generator is relatively resistant to the negative feedback effects of progesterone.  Study aims to evaluate the association of Anti-mullerian hormone with serum androgen and gonadotropin level in adolescents and young women of Polycystic Ovary Syndrome (PCOS).Methods: This was a single centre observational Cross-sectional study carried out in the department of Endocrinology and metabolism, Medical College, Kolkata from March 2017 to January 2019. Total number of study subjects were 207 out of which 138 were cases.Results: The AMH had strong positive correlation with serum testosterone in both case and control groups (r 0.542, p<0.001 and r 0.57, p<0.001) respectively .After the adjustment of age and BMI , the AMH moderately positive  but extremely significant correlation with serum testosterone as compare to control.Conclusions: Hyperandrogenaemia and higher ratio of LH and FSH associated with higher serum AMH level is associated with the higher serum AMH in polycystic ovarian syndrome

Nephrotoxicity in krait bite: a rare case series of three fatalities in consecutive bites by a single snake

Abstract Background Death due to poisonous snakebite is a formidable health hazard. It is a matter of concern especially in agrarian countries. Clinically snakebite envenomation are neurotoxic and vasculotoxic. Krait (Bungarus faciatus) Venom is essentially neurotoxic.Nephrotoxicity in krait bite is an important issue that has been less studied and reported. Case presentation In the present series, we report three cases of deaths in consecutive bites by a single banded krait.Significant renal involvement was found at autopsy. The kidneys showed interstitial haemorrhage and inflammatory cell infiltration. The renal changes were similar in all the three cases bitten by the same snake. Conclusions From the findings of autopsy and histology of the present case series we can conclude that nephrotoxicity is an important effect of krait bite. Though less reported and researched kidney changes in krait bite is a significant issue in treatment as well as autopsy diagnosis. . We can also infer that the immunogenicity of the snake venoms can be different from our expectation

Indolylquinoline derivatives are cytotoxic to Leishmania donovani promastigotes and amastigotes in vitro and are effective in treating murine visceral leishmaniasis

A wide variety of biologically active compounds contain indole and quinoline nuclei. Some novel indolylquinoline derivatives were synthesized from indole by Friedel-Crafts acylation reaction. Out of the four derivatives tested, 2-(20-acetamidobenzyl)-3-(39-indolylquinoline) (C) had no effect on the promastigotes or amastigotes of Leishmania donovani in vitro. The remaining three analogues, 2-(20-dichloroacetamidobenzyl)-3-(39-indolylquinoline) (A), 2-(20- chloroacetamidobenzyl)-3-(39-indolylquinoline) (B), and 2-(20-aminobenzyl)-3-(39-indolylquinoline) (D), inhibited the growth of L. donovani promastigotes in vitro and were cytotoxic to both the promastigote and amastigote forms of the parasite. These three derivatives were also effective in eliminating L. donovani amastigotes from BALB/c mouse peritoneal macrophages in vitro. One indolylquinoline derivative [A] was used to treat established visceral leishmaniasis in BALB/c mice. This compound was significantly more effective than sodium antimony gluconate (SAG) in reducing the splenic parasite load at a much lower concentration (5% of SAG). Our results suggest that indolylquinoline derivatives may be exploited as antileishmanial agents

Visceral Leishmaniasis in India: Promises and Pitfalls of a PCR-Based Blood Test

Traditional methods of diagnosing visceral leishmaniasis (kala-azar) in India suffer from a number of disadvantages. Amplification of multicopy nuclear genes and messenger ribonucleic acid of Leishmania by the polymerase chain reaction (PCR) was evaluated as an alternative assay under various clinical conditions. PCR of peripheral blood has the highest absolute sensitivity among all the available procedures, and is particularly useful for detecting parasites in early infections, post kala-azar dermal leishmaniasis, concurrent infections and immunocompromised cases, but is not so reliable for late infections. PCR of immunopurified blood mononuclear cells indicated the association of parasites with monocytes as well as non-monocyte cell types

Can a brief period of double J stenting improve the outcome of extracorporeal shock wave lithotripsy for renal calculi sized 1 to 2 cm?

Purpose: Extracorporeal shock wave lithotripsy (ESWL) is an established modality for renal calculi. Its role for large stones is being questioned. A novel model of temporary double J (DJ) stenting followed by ESWL was devised and outcomes were assessed. Materials and Methods: The study included 95 patients with renal calculi sized 1 to 2 cm. Patients were randomized into 3 groups. Group 1 received ESWL only, whereas group 2 underwent stenting followed by ESWL. In group 3, a distinct model was applied in which the stent was kept for 1 week and then removed, followed by ESWL. Procedural details, analgesic requirements, and outcome were analyzed. Results: Eighty-eight patients (male, 47; female, 41) were available for analysis. The patients’ mean age was 37.9±10.9 years. Stone profile was similar among groups. Group 3 received fewer shocks (mean, 3,155) than did group 1 (mean, 3,859; p=0.05) or group 2 (mean, 3,872; p=0.04). The fragmentation rate was similar in group 3 (96.7%) and groups 1 (81.5%, p=0.12) and 2 (87.1%, p=0.16). Overall clearance in group 3 was significantly improved (83.3%) compared with that in groups 1 (63.0%, p=0.02) and 2 (64.5%, p=0.02) and was maintained even in lower pole stones. The percentage successful outcome in groups 1, 2, and 3 was 66.7%, 64.5%, and 83.3%, respectively (p=0.21). The analgesic requirement in group 2 was higher than in the other groups (p=0.00). Group 2 patients also had more grade IIIa (2/3) and IIIB (1/2) complications. Conclusions: Stenting adversely affects stone clearance and also makes the later course uncomfortable. Our model of brief stenting followed by ESWL provided better clearance, comfort, and a modest improvement in outcome with fewer sittings and steinstrasse in selected patients with large renal calculi