Effect of Chitosan Irrigant and Lubricating Gel on Bond Strength of Resin Sealer to Radicular Dentin: An In Vitro Study.

BACKGROUND: The adhesive strength of sealers to dentin is influenced by various factors, and the presence of a smear layer is among the critical variables. Chitosan, known for its dentin compatibility, has previously demonstrated a reduction in dentin change and resin sealer bond strength comparable to ethylenediaminetetraacetic acid (EDTA) when used as an irrigant and final rinse. The study investigates the impact of chitosan, used as both a lubricating gel and final rinse, on the push-out bond strength of resin sealer. MATERIALS AND METHOD: Forty single-rooted premolar teeth, each with a fully formed root and a single root canal, were collected post-extraction. During canal preparation, 1 ml sodium hypochlorite (3%) was used for irrigation at every change of instrument, followed by applying specific chelating gel and final rinse for each experimental group. The groups included: Group 1 (17% EDTA chelating gel, final rinse with saline), Group 2 (17% EDTA chelating gel, final rinse with 17% EDTA solution), Group 3 (chitosan chelating gel, final rinse with saline solution), and Group 4 (chitosan chelating gel, final rinse with 0.2% chitosan solution), 10 specimens in each group. After obturation, specimens were sealed and incubated for a week at 37°C with 100% humidity. The universal testing machine was used for push-out tests, and specimens were examined using a scanning electron microscope (SEM) to identify various types of bond failure. RESULTS: Among the four groups, Group 2 exhibited the highest mean push-out bond strength (7.33 ± 0.26 MPa), followed by Group 4 (5.33 ± 0.25 MPa), Group 1 (4.61 ± 0.30 MPa), and Group 3 (2.94 ± 0.32 MPa). The variations in bond strength suggest a notable impact of the chelating agents and final rinse solutions on the resin sealer's interaction with dentin. CONCLUSION: The study concludes that the use of EDTA as both a lubricating gel and a final rinse significantly enhances push-out bond strength, outperforming chitosan in this study. Groups with saline as the final rinse (Group 1 and Group 3) exhibited the least bond strength, highlighting the importance of the final rinse in root canal therapy.

Theoretical, structural, and electronic analyses of pyridin-based dyes for dye-sensitized solar cells applications.

CONTEXT: The new series of donor-π-acceptor dyes have been designed using pyridine derivatives as a donor group and thienothiophene as a π-spacer group, which were linked via 10 acceptor groups. The highest occupied molecular orbital energies range from - 6.177 to - 5.786 eV, whereas the lowest unoccupied molecular orbital energies range from - 2.181 to - 3.664 eV. A6 dye has smaller energy gap, lower hardness, higher electrophilicity index, and good photovoltaic performance than other sensitizers. The lowest dihedral angle is observed in A1, A2, A6, A7, and A8 which are appropriate for intramolecular charge transfer between the molecules. The A8 has higher light harvesting efficiency, which increases the photovoltaic efficiency of the designed dye. The A6, A7, and A8 dyes spend less time in the excited state, which means they emit photons more efficiently than other dyes. The interaction between donor to π-spacer (red line) parts of the dyes has the bonding interaction (positive), and π-spacer to acceptor (blue line) parts of the dyes have the bonding and antibonding (negative) behaviours. The dyes A5 and A9 have 305.79 and 357.71 times higher ß0 values than urea (0.781 × 10-30 esu) molecules. The spectral properties of the A6 dye strongly affect the structural modification. METHODS: The density functional theory (DFT) and time-dependent DFT (TD-DFT) approach B3LYP/6-311G (d,p) basic set were used to optimize the designed dyes. All the calculations are performed using Gauss view 6.0 and Gaussian 09 software. The density of state spectrum is plotted using Gauss sum 2.6.

Bioconjugation of Meldrum's acid activated furan: A detergent compatible assay for protein quantitation.

A simple yet efficient assay for the quantitation of proteins ranging from plasma proteins to purified proteins from whole cell lysate, based on the bioconjugation reaction between protein and Meldrum's acid Activated Furan (MAF) is described. This easy to use, sensitive method is based on the conjugation of amine functionalities present on the protein with MAF to form the corresponding Donor Acceptor Stenhouse Adducts (DASAs) with characteristic absorption in the visible region. The reaction is rapid as well as reproducible and shows a proportionate increase in color change over a broad range of protein concentration. The assay was found to be sensitive up to 0.125 mg/mL concentration of the protein and was compatible with most of the commonly employed detergents and isolation protocols which makes it ideal for the estimation of protein samples containing detergents. Another striking feature of this protocol is its tolerance towards other major interference contributors such as chelating agents, reducing agents, carbohydrates and protease inhibitors.

Prognostication of the neurological outcome of tethered cord based on intraoperative neuromonitoring findings: how close can we get?

PURPOSE: To evaluate the correlation of intraoperative neuromonitoring (IONM) data in surgery for tethered cord syndrome (TCS) in children to the neurological outcome at 1-year follow-up. METHODS: 208 consecutive patients operated on for TCS, between January 2011 to February 2020, under electrophysiological monitoring in the Division of Paediatric Neurosurgery, AIMS, Kochi, India, were included. Their preoperative neurological, urological and orthopaedic status were compared with the postoperative status at 1 year follow-up. RESULTS: Our study prospectively collected the IONM data and retrospectively correlated it to the children's neurological outcome on follow-up. Out of 208 children, 28% (n = 59/208) had motor, 35% (n = 73/208) had bladder and 26% (n = 54/208) had bowel disturbances. Postsurgery, at one-year follow-up, 91% (n = 52/57) of the patients who had motor deficits had improvement, 82.3% (n = 51/62) of patients who had bladder deficits showed an improvement, and 88.8% (n = 48/54) with bowel deficits showed improvement. The monitorability for motor and sphincter potentials were 99.4% and 89.3%, respectively. Except for four patients (3 with bladder and 1 with motor worsening), all the patients who were monitorable with no deficits remained intact except for four patients, all the patients who had deficits and were monitorable improved after detethering (at 1 year). Clinical worsening corresponded to those who had a drop in amplitude of baseline TcMEP (n = 4). 18 events showed an increase in amplitude compared to the baseline TcMEP. These patients improved clinically on follow-up (at 1 year). CONCLUSIONS: IONM complements the preoperative clinical details in predicting immediate and long-term outcomes.

Concomitant Existence of Paroxysmal Nocturnal Hemoglobinuria in a Patient with Hb E (HBB: c.79G>A) Trait.

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal disorder that manifests with bone marrow failure, thrombosis and hemolysis. We present a 28-year-old male who presented with weakness, jaundice and transfusion dependence. On initial investigation, he was found to have anemia with jaundice with hemoglobin (Hb) capillary zone electrophoresis suggestive of Hb E (HBB: c.79G>A) trait. The same anomaly was also found in his mother. However, transfusion requirement was an unusual feature in the patient. As his corrected reticulocyte count was raised along with lactate dehydrogenase (LDH), which was suggestive of a hemolytic process, he was worked-up for the same. However, the direct Coombs test was negative. A bone marrow aspiration and biopsy was done to rule out hypersplenism but it revealed erythroid hyperplasia with reduced iron stores despite normal ferritin and iron studies. This was unusual as the patient had anemia requiring transfusions. He had no history of hemoglobinuria but a PNH by flowcytomety revealed a large clone of 81.2% in granulocytes and 88.5% in monocytes. The patient was started on Danazol and steroids for anemia which improved. He was counseled for matched sibling stem cell transplant. He had a full match with his brother. At the time of this study he awaits his transplant.

Green synthesis of gold nanoparticles using extracellular metabolites of fish gut microbes and their antimicrobial properties.

In the present study, we synthesis nanoparticles using biosynthesis methods because of the eco-friendly approach. Gold nanoparticles were synthesized using extracellular metabolites of marine bacteria (Rastrelliger kanagurta, Selachimorpha sp., and Panna microdon). After the synthesis gold nanoparticles checked their antibacterial and antimycobacterial activities. Here we have few techniques that have been used for characterizing the gold nanoparticles followed by ultraviolet (UV)-visible spectrophotometer analysis, Fourier transform-infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscopy (TEM). We observed the formation of gold nanoparticles using UV-Vis spectroscopy (UV-Vis). FT-IR spectroscopy results of the extracellular metabolites showed that different characteristic functional groups are responsible for the bioreduction of gold ions. In the recent years, we used zebrafish for an animal model to estimate nanoparticle toxicity and biocompatibility. We tested toxicity of the gold nanoparticle using the zebrafish larvae that are growing exponentially. Sample 1 showed a good antimicrobial activity, and sample 5 showed a good antimycobacterial activity. Based on the UV spectrophotometer, sample 1 is used for further studies. Color change and UV spectrum confirmed gold nanoparticles. Based on the TEM and SEM particles, size was measured and ranged between 80 and 45 nm, and most of the particles are spherical and are in rod shape. XRD result showed the gold nanoparticles with crystalline nature. Toxicity studies in the zebrafish larvae showed that 50 µg ml-1 showed less toxicity. Based on the studies, gold nanoparticle has good antibacterial and antimycobacterial activities. The present was concluded that gold nanoparticles have potential biocompatibility and less toxicity. Gold nanoparticles will be used as a drug molecule in pharmaceutical company and biomedicine application.

Pharmacological credence of the folklore use of Bauhinia malabarica in the management of jaundice.

The information on the hepatoprotective effect of Bauhinia malabarica Roxb. (Family Leguminosae) used in the folkloric medical practice in Malabar coast and Walayar valley of southern India for the treatment of liver related disorders is completely unknown. Hence, the efficacy of the aqueous methanolic extract of stem bark of B. malabarica (AqMeOH-Ba) was evaluated for liver function serum biochemical markers along with the antioxidant markers in liver tissues of Wistar albino rats. The biochemical observations as well as the histopathological examination of liver sections manifested considerable hepatoprotective activity of B. malabarica stem bark, and thus validated the folkloric claim.

Serodiagnosis of Scrub Typhus at a Tertiary Care Hospital from Southern India.

INTRODUCTION: Scrub typhus, a zoonotic disease is one of the most covert emerging and re-emerging Rickettsial infections. There is an upsurge in the incidence of the disease worldwide with ever-changing habitat. Clinical diagnosis of scrub typhus is challenging as the signs and symptoms of scrub typhus are similar to other febrile illnesses. In developing countries, among the various laboratory tests to diagnose scrub typhus, Weil-Felix test is commonly performed despite its low sensitivity. The Immunofluorescence antibody (IFA) test has its limitations in terms of cost and expertise required. The present study was conducted to determine the seropositivity of IgM ELISA for scrub typhus in clinically suspected cases. MATERIALS AND METHODS: Weil-Felix test and IgM ELISA were performed using clinically suspected cases of scrub typhus using commercially available kits. RESULTS: Out of 482 samples tested, 109 were positive by both Weil-Felix test and IgM ELISA. One hundred and sixteen samples which were negative by Weil-Felix test reacted positive by IgM ELISA. Fourteen samples which were positive by Weil-Felix test were negative by ELISA. CONCLUSION: Owing to the limitations of the Weil-Felix test and IFA, commercially available recombinant IgM ELISA which has a good sensitivity and specificity may be an alternative in laboratories with moderate set up.

TLC and HPTLC Fingerprints of Various Secondary Metabolites in the Stem of the Traditional Medicinal Climber, Solena amplexicaulis.

Aim of this study was to develop a TLC and a HPTLC fingerprint profiles for various secondary metabolites of methanol extracts of the stem of the traditional medicinal climber, Solena amplexicaulis. These studies were carried out as per the methods of Harborne and Wagner et al. The profiles of various individual secondary metabolites were made and developed for authentication. The methanol extract of the stem showed the presence of 6 alkaloids, 6 flavonoids, 2 glycosides, 9 saponins and 3 terpenoids. Owing to the presence of rich variety of secondary metabolites, the stem extract of S. amplexicaulis is expected to exhibit therapeutic properties.

Hydrolysis of acid and alkali presoaked lignocellulosic biomass exposed to electron beam irradiation.

In this study, synergetic effect of mild acid and alkali with electron beam irradiation (EBI) on the enzymatic hydrolysis of a selected grass biomass was assessed. Biomass samples prepared by soaking with 1% H2SO4, or 1% NaOH, were exposed to 75 and 150 kGy of EBI. Water presoaked biomass was used as control. Hydrolysis of pretreated samples was carried out using cellulase (15 FPU/g biomass) for 120 h. Structural changes were studied by FTIR and XRD analyses. Reducing sugar and glucose yields from enzymatic hydrolysis were significantly higher in acid and alkali presoaked EBI exposed samples. Theoretical glucose yield showed 40% increase from control in alkali presoaked EBI exposed (150 kGy) samples. Removal of hemicellulose, decreased crystallinity and structural changes were major factors for the combined treatment effect favoring the hydrolysis.

Enzymatic hydrolysis and characterization of lignocellulosic biomass exposed to electron beam irradiation.

Pretreatment of lignocellulosic biomass has been taken up as a global challenge as it comprises a large renewable source of fermentable sugars. In this study, effect of electron beam irradiation (EBI) on a hybrid grass variety investigated as a biomass pretreatment method. Dry biomass samples after characterization were exposed to EBI doses of 0, 75, 150 and 250 kGy. The pretreated biomass samples were enzymatically hydrolyzed using Trichoderma reesei ATCC 26921 cellulase for 144 h. The enzyme loadings were 15 and 30 FPU/g of biomass. The structural changes and degree of crystallinity of the pretreated biomass were studied by FTIR, XRD and SEM analyses. The lignocellulosic biomass sample showed 12.0% extractives, 36.9% cellulose, 28.4% hemicellulose, 11.9% lignin and 8.6% ash. Significant improvements in the reducing sugar and glucose yields were observed in the hydrolysate of EBI pretreated biomass compared to the control. In 250 kGy exposed samples 79% of the final reducing sugar yield was released within 48 h of hydrolysis at an enzyme loading rate of 30FPU/g of biomass. The IR crystallinity index calculated from the FTIR data and degree of crystallinity (XRD) decreased in the EBI treated samples. A significant negative correlation was observed between degree of crystallinity and the glucose yield from enzymatic hydrolysis.