Search

Prediction of number of [Pi]-bonds, [sigma]-bonds, single and triple bonds of aliphatic unsaturated open-chain and cycloalkynes is a vitally important tool for students of chemistry at undergraduate and graduate level for solving different kinds of problems regarding different chemical reactions. In this manuscript, we try to present a simple and innovative method for easy calculation of number of [Pi]-bonds, [sigma]-bonds, single and triple bonds with the help of completely 8 (eight) new formulae.

Introduction: Breast carcinoma is the most common malignant tumour and is the leading cause of carcinoma death in women. Assessing Vascular Endothelial Growth Factor-C (VEGF-C) is important because the expression of VEGF-C is one of the factors determining the aggressiveness of breast carcinoma. Aim: To evaluate the expression of VEGF-C in breast carcinoma and its association with HER2/neu and Oestrogen Receptors (ER)/Progesterone Receptors (PR). Materials and Methods: A cross-sectional observational study was carried out in Department of Pathology of a tertiary care center of Burdwan Medical College and Hospital, West Bengal from 1st January 2018 to 30th June 2019. Patients attending Outpatient Department (OPD) and were diagnosed clinically as having breast cancer, operated upon, and subsequently sent for Histopathological Examination (HPE) in Pathology. The samples which were positive for breast carcinoma by histopathology were further studied with Immunohistochemical (IHC) markers and the positivity of IHC expression was reported using standard procedure and scoring pattern. The assosciation of VEGF-C expression with respect to histological type, grade, and stage of cancer as well as the HER2/neu and ER/PR status was studied. Using the Statistical Package for Social Sciences (SPSS) version 18.0, Chi-square was applied for the significance of p-value and the significance level was considered at a p-value

Introduction: Coronavirus Disease 2019 (COVID-19) pandemic has compelled medical education institutes to impart knowledge to the undergraduate MBBS students through online medium. In order to adopt the new online pedagogy it is important to understand perceptions of students and their educators. Further, it is imperative for us to know the shortcomings of online teaching methodologies to develop and inculcate newer teaching methods to maintain quality education. Aim: To understand the perception and challenges faced by the first year MBBS students, faculty and their parents during the compelling online classes as teaching methodology compared to Offline. Materials and Methods: The present study was questionnaire- based, cross-sectional conducted in the Department of Biochemistry, Employees’ State Insurance Corporation (ESIC) Medical College and Hospital, Faridabad, Haryana, India, between August 2021 and October 2021. The present study included students of MBBS first year (n=123), faculty (n=27) from ESIC Medical College and Hospital, Faridabad, India, and parents/ guardians of students (n=94). A five-point Likert scale was used to determine the perception of students/faculty/parents. Mean value calculated greater than 3 was considered disagreement and less than 3 as agreement. Online mode (Edumarshal software, Google forms) was used. Statistical analysis was done calculating mean, Standard Deviation (SD) and Paired t-test was used to study significance of study parameters on continuous scale. Results: Student’s perception was that offline teaching was significantly better than online classes in term of enthusiasm, interaction, clarity, periodic assessments (p-value

Abstract Aqueous rechargeable mixed‐ion batteries (ARMBs), where two types of ions shuttle between the cathode and anode, are an important alternative to conventional non‐aqueous electrolyte‐based rechargeable batteries. Herein, we present fundamental insights into the function of an ARMB comprising of NASICON‐based sodium titanium phosphate (NaTi2(PO4)3/NTP) and olivine‐based lithium iron phosphate (LiFePO4/LFP) employed as the anode and cathode respectively in combination with mixed‐ion electrolytes, x‐M Li2SO4: y‐M Na2SO4 (x+y=1). Electrochemical and ex situ structural studies interestingly reveal a preferential Na+‐ion insertion into NTP, despite the presence of two different cations in the electrolyte. This is strongly supported by molecular dynamics simulations, which show a 1–2 orders higher diffusion coefficient for Na+‐ion than Li+‐ion in NTP. In contrast, co‐insertion of Li+ and Na+‐ions into LFP takes place when cycled in mixed‐ion electrolytes. We also show that batteries with mixed‐ion electrolytes perform better than electrolytes with individual cations.

Hydrothermal method was employed for the synthesis of TiO2 nanoparticles and the synthesis of graphitic-carbon nitride (g-C3N4) was carried out by thermal polymerization of dicyandiamide. Thermal deposition method was employed to couple TiO2 with g-carbon nitride (g-C3N4). The synthesized materials were confirmed by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX) analysis. Synthesized TiO2 nanoparticles and TiO2/g-C3N4 composites were employed for the removal of chromium in wastewater by adsorption studies. Higher percentage of chromium removal was observed with TiO2/g-C3N4 composite because of sheet like morphology and higher porosity of the material.

Superatom molecular orbitals (SAMOs) are atom-like molecular orbitals that have been observed in the buckminsterfullerene C60 molecule. We studied the ice-like water cluster (H2O)10 that is expected to be ubiquitous in nature in nanoscale microenvironments at ambient temperatures due to the nanoconfinement effect. We report for the first time the theoretical prediction of the existence of SAMOs in the adamantanoid nanostructured water cluster (H2O)10. The geometry of the adamantanoid water cluster (H2O)10 was optimized using the Restricted Hartree-Fock method and the ab-initio second-order Møller-Plesset perturbation theory (MP2) method, as well as the aqueous solvent phase polarizable continuum method (PCM). The optimized (H2O)10 structure is a distorted adamantanoid that closely matches the crystal structure of (H2O)10 that was previously reported. The theoretical studies using Hartree-Fock (HF), MP2, or Density Functional Theory (DFT) predict that the adamantanoid water cluster (H2O)10 exhibits SAMOs in the low-lying LUMOs. The orbital energies calculated with these methods are reported. The lowest-lying SAMOs in the water cluster (H2O)10 is the most intriguing SAMO due to its s-orbital character and potential to delocalize electrons in a large area that surrounds the cluster. The electron affinity of the water cluster (H2O)10 was calculated using HF, MP2, and DFT methods and the values obtained from each method were (kJ/mol) +74.71, -770.58, and -48.57, respectively. The existence of SAMOs in low-lying LUMO levels indicate of possible supramolecular chemistry of the water clusters with interfacial implications in nanoconfined spaces. Overall, these theoretical results predict new fundamental properties of water clusters that may have deep implications and impact in biological and nanotechnology systems that involve nanostructured water in confined spaces.

Background: According to previously published research, different analytical methods (GC, HPLC, etc.) were used to determine Valproic acid and its Genotoxic impurities. The heavy metals were also attempted to be determined using the ICP-MS technique in other drug substances. Methods: The present work evaluated the 10 elemental impurities (Cd, Pb, As, Hg, Co, V, Ni, Fe, Al, and Sn) in Valproic acid by ICP-MS method utilising a microwave-assisted acid digestion process as there is no analytical method for the heavy metal analysis in Valproic acid. Results: The developed analytical method was selective, sensitive and rapid for capable of detecting heavy metal at 0.19 ppm As, 0.38ppm Hg, 0.06 ppm Pb, 0.06ppm Cd, 0.63 ppm Co, 1.25ppm V,2.5 ppm Ni, 25 ppm Fe, 25 ppm Al and 75 ppm Sn and further quantified from 0.375ppm As,0.75ppm Hg, 0.125 ppm Pb, 0.125ppm Cd, 1.25ppm Co, 2.5ppm V, 5 ppm Ni, 50 ppm Fe, 50ppm Al and 150 ppm Sn to 200 percent of limit concentration. The analytical method found to be linear with correlation coefficient > 0.99. The percentage recoveries of heavy metals at three different concentrations with spiking in samples of Valproic acid were achieved an acceptable range at 70% to 150 %. The method was precise and robust and its relative standard deviation was below 20%. The actual % RSD in precision are 1.0 % As, 0.5 % Hg, 0.5 % Pb, 1.2 % Cd,0.6 % Co, 0.6 % V, 0.6 % Ni, 0.5% Fe, 0.9 % Al and 0.3 % Sn. Conclusion: Heavy metal analysis by ICP-MS is a powerful technique, Therefore the developed method can use for routine quantitative determination of 10 elemental impurities in Valproic Acid.

Biopolymers like cellulose, polysaccharides, chitosan, starch, chitin, and alginates have sparked an increasing curiosity in creating natural replacements for synthetic polymers during the last several decades. Chitin is a major part of fungi’s cell walls, the crustaceans’ exoskeletons, like lobsters, crabs, and shrimps, cephalopod beaks, the radulae of mollusks, and fish and lissamphibians scales. Since the late 1970 s, biopolymer chitosan has gathered interest in basic science and applied research due to its incredible macromolecular framework, physicochemical properties, and biological activities, which differ from those of synthetic polymers. Chitin and derivatives thereof have practical usages in chemistry, the agriculture sector, medicine, cosmetics, as well as textile and paper industries. Chitosan has also received a lot of recent interest in the fields of dentistry, ophthalmology, veterinary science, biomedicine, the drink industry, hygiene and personal care, catalysis, chromatography, sewage treatment, and biotechnology. Numerous fundamental investigations have been conducted on chitin and chitosan. This article presents a short compact summary of research over the last two decades in an attempt to highlight the works on chitin and chitosan applications.

The current study focuses on the development of duplex Ni-P/Ni-Cu-P coatings by the electro­less deposition method. Coatings are developed on mild steel substrates with Ni-Cu-P as the outer layer and Ni-P as the inner layer and vice versa. The coated samples are heat-treated at temperatures ranging between 200 to 800 °C during 1 and 4 h. Coated samples are characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The effect of heat treatment tempera­ture and its time duration on the hardness, friction and wear behaviour of both coatings are evaluated and compared. This would help in understanding how heat treatment influences the duplex system of coatings and helps in identifying the suitable condition of heat treatment for optimal performance of the coating. It is observed that heat treatment has a positive influence over the coating performance, which is the best when treated under optimal temperature and time duration conditions. The corrosion behaviour of the coatings is also assessed with the help of electrochemical techniques, viz. potentiodynamic polari­zation and electrochemical impedance spectroscopy. The results show that the duplex coat­ings can provide substantial protection to the mild steel substrates. Heat treatment is also found to have a significant influence on the corrosion behaviour of duplex coatings.

A hydrazone (1) based on 2-hydroxyquinoline-3-carbaldehyde was synthesized and its anion and cation detection ability were studied. It could detect both fluoride in acetonitrile selectively among anions and copper ions in semiaqueous medium among cations. The addition of fluoride ion to the acetonitrile solution of the receptor produced a sharp colour change from light yellow to bluish green. The corresponding UV-vis measurements showed a red shift of the band of receptor 1 for fluoride and a blue shift of the band for copper ions. The fluorescence intensity of the receptor 1 got quenched with both fluoride and copper ions. The detection limits for both the ions are in order of micromolar level. The practical applications of fluoride detection were extended to oral care products. Key words: hydrazone, fluoride, copper, colorimetric, fluorescent probe. Nous avons synthetise une hydrazone (1) derivee du 2-hydroxyquinoline-3-carbaldehyde et nous avons etudie sa capacite a detecter des anions et des cations. La sonde s'est revelee capable de detecter selectivement les ions fluorure parmi d'autres anions dans l'acetonitrile ainsi que les ions de cuivre parmi d'autres cations dans un milieu semi-aqueux. L'ajout d'ions fluorure a la solution du recepteur dans l'acetonitrile a provoque un changement abrupt de couleur, qui est passee du jaune pale au vert bleute. La spectrometrie d'absorption UV-visible a revele dans les spectres correspondants un deplacement vers le rouge de la bande du recepteur 1 dans le cas des ions fluorure et un deplacement vers le bleu de cette bande dans le cas des ions de cuivre. L'extinction de l'intensite de fluorescence du recepteur 1 a ete observee tant avec les ions fluorure qu'avec les ions de cuivre. Les limites de detection des deux ions sont de l'ordre du micromolaire. La detection du fluorure a ete appliquee en pratique a des produits de soins buccaux. [Traduit par la Redaction] Mots-cles : hydrazone, fluorure, cuivre, colorimetrique, sonde fluorescente., Introduction Designing molecular systems for detecting cations, anions, or neutral molecules has been a prime target in the recent decade due to the varied environmental and biological significance of these [...]

An efficient and facile method for the synthesis of substituted imidazoles (10a-10g) has been reported by reacting substituted aldehydes (1–7), benzil (8) and ammonium acetate [9] in presence of reuseable solid acid catalyst viz. Rice Husk Ash.SO3H (RHA.SO3H) at room temperature. The homogeneity of compounds was confirmed by melting point and thin layer chromatography. All synthesized compounds (10a-10g) were characterized by 1H NMR and FTIR spectral techniques. The prepared catalyst has been characterized by SEM, TEM and X-ray diffraction methods. All synthesized compounds were further tested for in vitro herbicidal activity against Raphanus sativus L. seeds. The compounds were also screened for their antifungal activity against Rhizoctonia solani and Aspergillus niger by poisoned food technique method. From bio evaluation data, it was found that compounds 10c and 10a were most active against Raphanus sativus L. seeds. Compound 10g was found most active against R. solani fungus at highest concentration. Compound 10f has shown maximum percentage growth inhibition i.e. 71.89 against A. niger at 200 ​μg/mL concentration.

Quadruply bonded dirhenium(III) complex (Bu4N)2[Re2Cl8] (1) reacts with sodium salts of dimethyldithiocarbamate, diethyldithiocarbamate and pyrrolidinedithiocarbamate in ethanol under stirring condition to afford the dithiocarbamato chelated chloro bridged linear trinuclear rhenium complexes of the type [Re3(μ-Cl)2(η2-LR)6(OH2)2][ReO4] (2(LR)) where LR represents the dithiocarbamato ligands [LR = S2CNMe2, 2(LMe); S2CNEt2, 2(LEt) and S2CN(CH2)4, 2(LPyr)]. These are the first examples of rhenium complexes in which the novel linear [Re–Cl–Re–Cl–Re] unit is present. These complexes have very similar spectral and electrochemical properties which are also reported. Structural identity of the complex 2(LEt) has been established by X-ray crystal structure determination. Density functional theory calculation shows that for 2(LEt), both the HOMO and LUMO are mainly composed of rhenium d-orbitals and LEt ligands p orbitals.

Supercapacitors have drawn our attention exceptionally in the last few decades due to their substantial applications, but the majority has focused on different metal oxides/metal hydroxides composite electrode materials. Here, we have synthesised spherical honeycomb like ZnMn2O4@Ni(OH)2 (ZMN) core–shell electrode material by a facile, substrate free and cost-effective hydrothermal protocol. The novel electrode material, such as spherical ZMN exhibits high specific capacitance of 2577.44F g−1 at 1 A g−1 with incredible cyclic stability of 94.8% capacitance retention after 3000 cycles a 1 A g−1. Additionally, a solid-state asymmetric device has been fabricated by using ZMN and activated carbon (AC) as positive and negative electrodes, respectively. This asymmetric device exhibits a high energy density of 43.17 Wh kg−1 at a power density of 374.98 W kg−1 and retains a very high energy density of 15.18 Wh kg−1 at the power density of 5972.9 W kg−1. More importantly, this device holds a long-term cycling stability, with ≈ 90.46 % capacity retention after 10,000 cycles at 1 A g−1. These results reveal high potential for making an ASC device with high energy and power densities for electronic applications.

Green approach to synthesize MnxZn1-xO [x ​= ​0.05 (MNZ†), 0.1 (MNZ1), 0.2 (MNZ2), 0.3 (MNZ3), and 0.4 (MNZ4)] nanocomposites via co-precipitation method under the controlled condition at pH∼8–9 and its application was found in multidimension like photocatalytic, fluorescence and antibacterial activity. The X-ray powder diffraction (XRD), Furrier Transform Infrared (FT-IR), Scanning electron microscopy (SEM), UV–Vis absorption and Fluorescence spectroscopy techniques were used for the characterization of the prepared nanocomposite. The most thrilling phenomena is that MNZ catalyst have promising fluorescence characteristics with contains mixture of Mn(II)/Mn(III) and also good agreement with XRD, which differ from other Mn based ZnO. The result shows that the MnxZn1-xO (x ​= ​0.1) (MNZ1) catalyst exhibits remarkable photo catalytic activity (rate k ​= ​61.88 ​× ​10−3min−1) for photo-oxidation of Naphthol Orange (NO) under sunlight irradiation compared to other compositions of MNZ and ZnO. The optical band gap of MNZ1 was found 2.85eV which suggest that it’s an excellent photocatalyst under sunlight and shows outstanding reusability without any loss of activity. The phase structure of MNZ1 was Wurtzite type hexagonal and the average crystallite size was 16.41±1nm at [101] measured from Scherrer equation. The grain size of MNZ1 was found to be 100±5nm at 50KX and it looks flex type shape. It also shows excellent antibacterial activity against Gram-positive bacteria and Gram-negative bacteria by agar well diffusion, Minimum Inhibitory Concentration (MIC) methods and found that MNZ1 has good antibacterial activity against S. aureus compared with its parent ZnO and MnCl2.

We demonstrate that colloidal quantum dots of CdSe and CdSe/ZnS are detected during the photooxidation of MeOH, under broad spectrum illumination (250 mW/cm2). The stepwise photocurrent vs. time response corresponds to single entities adsorbing to the Pt electrode surface irreversibly. The adsorption/desorption of the QDs and the nature of the single entities is discussed. In suspensions, the QDs behave differently depending on the solvent used to suspend the materials. For MeOH, CdSe is not as stable as CdSe/ZnS under constant illumination. The photocurrent expected for single QDs is discussed. The value of the observed photocurrents, > 1 pA is due to the formation of agglomerates consistent with the collision frequency and suspension stability. The observed frequency of collisions for the stepwise photocurrents is smaller than the diffusion-limited cases expected for single QDs colliding with the electrode surface. Dynamic light scattering and scanning electron microscopy studies support the detection of aggregates. The results indicate that the ZnS layer on the CdSe/ZnS material facilitates the detection of single entities by increasing the stability of the nanomaterial. The rate of hole transfer from the QD aggregates to MeOH outcompetes the dissolution of the CdSe core under certain conditions of electron injection to the Pt electrode and in colloidal suspensions of CdSe/ZnS.

Wheat (WBC) and rice straw biochars (RBC) prepared at 400 and 600 °C and their deashed counterparts were characterized for their physico-chemical properties using CHN analysis, Brunauer–Emmett–Teller (BET), X-ray fluorescence (XRF), scanning electron microscopy (SEM), 13C-nuclear magnetic resonance (NMR), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) techniques. Pyrazosulfuron-ethyl sorption data on normal and deashed biochars could be well fitted to the Freundlich model. The characteristics of biochars and their adsorption capacities for pyrazosulfuron-ethyl were affected by the pyrolysis temperature and nature of feedstock. Rice biochars had higher sorption capacities than the wheat biochars. Deashing of biochars further enhanced their herbicide adsorption potential by a factor of 2–3. Sorption of herbicide on both normal and deashed biochars was concentration dependent (1/n

Herein, a highly facile, rapid and one-pot approach has been applied for the synthesis of water soluble starch capped CdSe quantum dots (QDs) by using UV irradiation in the aqueous solution containing cadmium sulphate, sodium selenosulfate, acetone and 2-propanol. No external reducing agents were added to the solution, as the radicals generated in situ upon photoirradiation i.e., 2-hydroxy-2-propyl radicals, (CH3)2C·OH could reduce the precursor ions for the synthesis of these QDs. These QDs were characterised by various techniques such as UV–Vis absorption, XRD, Raman, FTIR, TEM and SEM measurements. The presence of strong quantum confinement effects could be realized from their very small size i.e., ∼3 nm as revealed by TEM studies. Besides, these QDs were found to exhibit photoluminescence (PL) in the longer wavelength region. The PL intensity as well as the charge carrier lifetime values could be conveniently tuned by simply varying the Cd to Se precursor ratio during the synthesis. Furthermore, a relatively novel approach has been adopted to extract these QDs from the colloidal solution by freezing it to 0 °C followed by de-freezing to room temperature. The extracted QDs were functionalized with thiourea in order to increase the PL quantum yield and the stability of the QDs. The effects of pH and temperature on the PL intensity of functionalized CdSe QDs were also investigated to explore their applicability in sensing of heavy metal ions. Interestingly, the QDs displayed highly selective PL quenching in the presence of Cu2+, Cr6+ and Hg2+ metal ions. The limits of detection for these metal ions have been determined and a probable PL quenching mechanism is postulated. Keywords: CdSe quantum dot, UV radiation, Starch, Surface functionalization, Sensor

Abstract The achiral tripeptide Boc‐Aib‐MABA‐Aib‐OMe has the ability to co‐exist as nanospheres and as a network of nanofibers in methanol. Furthermore, AFM and TEM images show the presence of bulges in the network of nanofibers. Interestingly, the formation of nanofibers is seen to emerge from the outer boundary of the spherical structures. Some of the nanofibers curl up at the tip and later result in the formation of hollow nanospheres with thick boundaries. The presence of β‐turn‐like structures with hydrogen bonding is observed using FT‐IR studies. The presence of hydrogen bonding is also demonstrated by using NMR studies.

A new UPLC method has been described to determine ketorolac tromethamine in pharmaceutical samples and biofluids. Drug was eluted using a reversed-phase Gemini 3U, C18, 110R (150 × 4.6 mm, 3 μm) column when a mobile phase composition 90:05:05 (v/v) consisting CH3OH, CH3CN and NaH2PO4 under isocratic program.Ketorolac tromethamine was eluted at a short of time 2.02 min. Ketorolac tromethamine isolated from biofluids after liquid-phase extraction. The results were linear up to 10 µg mL-1 with the correlation coefficients greater than 0.999. The sensitivity limits, LOD and LOQ were 0.016 and 0.051 µg mL-1, respectively. The method is simple, fast and reliable with good specificity and sensitivity and will be suitable for routine analysis of ketorolac tromethamine.