Fluorescent and Electrochemical Sensor Based on Basic Red 9 Dye Functionalised Graphene Oxide-Montmorillonite Composite for Selective Detection of Cerium (III) Ion.

In this work, graphene oxide (GO) has been prepared from used dry cells using modified Hummer's method and encapsulated with montmorillonite clay. To enhance its electrical property, the GO-MMT composite has been functionalised with Basic Red 9 dye. The sensor was characterized by various spectroscopic techniques like FT-IR spectroscopy, PXRD, SEM analysis, etc. Basic Red 9 dye functionalised GO-MMT composite has been employed for fluorescent and electrochemical detection of Ce3+ ion. The fluorescent turn-on sensing is sensitive, reversible and free from interference from other metal ions. The detection of Ce3+ ion by the sensor was also conducted in bovine serum albumin (BSA) medium. Pt electrode modified with the hybrid sensor produces excellent electrochemical change in presence of Ce3+ ion through cyclic voltammetry and square wave voltammetry technique. The limit of detection (LOD) from fluorescence spectroscopy, cyclic voltammetry and square wave voltammetry were calculated to be 0.6556 × 10- 9 M, 1.232 × 10- 9 M and 1.923 × 10- 9 M respectively.

Rosaniline Hydrochloride Encapsulated MCM-48: Fluorescent and Electrochemical Sensor for Dopamine.

The dye Rosaniline hydrochloride (RANH) has been successfully incorporated in MCM-48 (designated as RANH@MCM-48) and characterized by various spectroscopic methods including FT-IR, SEM, EDX and N2 adsorption-desorption isotherm. RANH@MCM-48 in aqueous medium acts as fluorescence "on" sensor for neurotransmitter dopamine (DA) in presence of its main biological interfering agent ascorbic acid or vitamin c (AA) along with Glucose, Cholesterol and Uric acid (UA). The limits of detection (LOD) were found to be 65 nM and 51 nM respectively in absence and in presence of AA. The interaction of DA to RANH@MCM-48 is found to be reversible with respect to EDTA2-. The fluorescence intensity vs. pH plot shows a narrow fluorescence window of 7.2 to 8.8. RANH@MCM-48 has been successfully applied for DA detection in artificial cerebrospinal fluid (ACF) and bovine serum albumin (BSA) with LOD values 27 nM and 22.5 nM respectively. Platinum disc electrode has been modified with RANH@MCM-48 which showed distinct oxidation peaks with a separation of 0.188 V in cyclic voltammetry (CV). The LOD for DA in presence of AA determined from oxidation current is 77.5 nM. The voltammetric detection of DA is found to be free from common interfering species Na+, K+, Ca2+, Fe2+, UA, Cholesterol and Glucose. RANH@MCM-48 has been found to be a very effective fluorescence and voltammetric sensor for DA with very low  LOD.

Condensation Product of 1-Naphthaldehyde and 3-Aminophenol: Fluorescent "on" Probe for Ce3+and "off" Probe for Dichromate (Cr2O72-).

A new probe (Z)-3-((naphthalen-1-ylmethylene)amino)phenol has been synthesized by condensation reaction between 1-naphthaldehyde and 3-aminophenol for the fluorescent sensing of Ce3+ by "on" mode and dichromate (Cr2O72-) by "off" mode. Metal ions-Ag+, Al3+, As3+, Ba2+, Ca2+, Cd2+, Ce4+, Co2+, Cr3+, Cr6+, Cu2+, Fe2+, Fe3+, Hg2+, K+, La+, Li+, Mg2+, Mn2+, Na+, Ni2+, Pb2+, Zn2+and anions Br-, C2O42-, CH3COO-, Cl-, CO32-, F-, H2PO4-, HCO3-, HF2-, HPO42-, I-, MnO4-, NO3-, OH-, S2-, S2O32-, SCN-, SO42- do not interfere. The limit of detection (LOD) for sensing Ce3+ and Cr2O72- ions are 1.286 × 10-7 M and 6.425 × 10-6 M, respectively.

Advancements in modification of membrane materials over membrane separation for biomedical applications-Review.

A comprehensive overview of various modifications carried out on polymeric membranes for biomedical applications has been presented in this review paper. In particular, different methods of carrying out these modifications have been discussed. The uniqueness of the review lies in the sense that it discusses the surface modification techniques traversing the timeline from traditionally well-established technologies to emerging new techniques, thus giving an intuitive understanding of the evolution of surface modification techniques over time. A critical comparison of the advantages and pitfalls of commonly used traditional and emerging surface modification techniques have been discussed. The paper also highlights the tuning of specific properties of polymeric membranes that are critical for their increased applications in the biomedical industry specifically in drug delivery, along with current challenges faced and where the future potential of research in the field of surface modification of membranes.

Managing ANCA-associated vasculitis during COVID-19 pandemic: a single-center cross-sectional study.

The objective of the study is to report the outcomes of COVID-19 in ANCA-associated vasculitis (AAV) patients. This was a registry-based observational study conducted at a tertiary care center in north India. AAV patients with at least one follow-up visit between March 2020 and September 2021 were included. Demographic features, clinical manifestations, disease activity, and treatment details of underlying AAV were noted in all patients. Details of COVID-19 infection including severity, treatment, and outcomes were noted. Predictors of COVID-19 severity were determined using univariate analysis. A total of 33 (18.3%) out of 180 AAV patients contracted COVID-19 infection. Moderate COVID-19 infection was seen in 33.3% and severe or critical infection was seen in 36.3% of patients. Seventeen patients (51.5%) required supplemental oxygen therapy. Nine patients had active disease at the time of COVID-19 infection and three of them died due to COVID-19 infection. The risk of COVID-19 infection and its severity did not differ between patients receiving different immunosuppressants including rituximab induction. Hypothyroidism (p = 0.046) and ocular (p = 0.038) involvement due to AAV predicted the development of moderate to severe/critical COVID-19. Three (9.1%) patients died from COVID-19 and the rate of AAV flare after COVID-19 was similar to that in non-COVID-19 patients (15.3/100 person-year vs. 15.6/100 person-year, p = 0.95). Majority of the patients with AAV had moderate to severe or critical COVID-19 infection. The rate of death due to COVID-19 in AAV is higher than in general population. Use of standard remission induction regimens did not lead to increased risk of COVID-19 infection in our AAV cohort.

Does the augmentation of monetary and non-monetary factors prerequisite for the improvement of health outcomes? Evidence from the Indian states.

The present study was conducted in Indian states to examine the effect of monetary and non-monetary factors on Infant Mortality Rate (IMR) and Life Expectancy at Birth (LEB) by using the panel regression model. In addition, an attempt was also made to analysis the unequal pattern of health infrastructure and services across states over time with the help of a composite index on health infrastructure and services. It was found that the index value of the best performing state Chhattisgarh is more than fourth six times that of the worst performing state. The study also showed that, despite the higher level of average per capita public health expenditure and moderately better health infrastructure, the COVID 19 induced death rate was high in Punjab, Sikkim, Delhi and Goa. The panel regression results revealed that, an average increase of 1% in the monetary factor, public health expenditure to Gross State Domestic Product ratio (PHEGSDPR), would decrease the average of IMR by about 10%. Moreover, the elasticity of IMR with respect to non-monetary factor, health infrastructure and services per 0.1 million population (HISPLP), was negative and significant. Likewise, the explanatory variables, HISPLP and PHEGSDPR have a positive and significant effect on the LEB.

Fluorescent Sensors for Hg2+ and Cu2+ Based on Condensation Products of 4H-1,2,4 Triazole-4-Amine and Carboxylated Benzoic Acids.

Mercury (Hg) causes serious health issues in its all forms. Deficiency as well as excess of copper ion (Cu2+) in human body is hazardous. A series of four compounds have been derived from carboxylated benzoic acids (benzoic acid, isophthalic acid, terephthalic acid and phthalic acid) and 4H-1,2,4 triazole-4-amine and characterized. Fluorescence detection of Hg2+ was recorded by the derivates with benzoic acid and isophthalic acid while the derivatives of terephthalic acid and phthalic acid detect Cu2+ by fluorescence "off" mode. Metal ions like Li+, Na+, K+, Zn2+, Al3+, Mg2+, Mn2+, Co2+, Ni2+, Cu2+, Cd2+, Pb2+ and Hg2+ found not to interfere. The stoichiometry of binding is 1:1 for the benzoic acid derivative with Hg2+ while it is 1:2 for the other three derivatives. The binding constants are ca. 10-4.5 between the sensors and Hg2+ or Cu2+ and detection limits are around 10-5.5 M. DFT calculation provided optimized geometries of the sensors and confirmed the stoichiometry of binding with Hg2+/Cu2+.

Nanomaterials for Biomedical Applications: Production, Characterisations, Recent Trends and Difficulties.

Designing of nanomaterials has now become a top-priority research goal with a view to developing specific applications in the biomedical fields. In fact, the recent trends in the literature show that there is a lack of in-depth reviews that specifically highlight the current knowledge based on the design and production of nanomaterials. Considerations of size, shape, surface charge and microstructures are important factors in this regard as they affect the performance of nanoparticles (NPs). These parameters are also found to be dependent on their synthesis methods. The characterisation techniques that have been used for the investigation of these nanomaterials are relatively different in their concepts, sample preparation methods and obtained results. Consequently, this review article aims to carry out an in-depth discussion on the recent trends on nanomaterials for biomedical engineering, with a particular emphasis on the choices of the nanomaterials, preparation methods/instruments and characterisations techniques used for designing of nanomaterials. Key applications of these nanomaterials, such as tissue regeneration, medication delivery and wound healing, are also discussed briefly. Covering this knowledge gap will result in a better understanding of the role of nanomaterial design and subsequent larger-scale applications in terms of both its potential and difficulties.

A New Schiff Base Based Fluorescent Sensor for Al(III) Based on 2-Hydroxyacetophenone and o-Phenylenediamine.

A simple Schiff base (L) based on 2-hydroxyacetophenone and o-phenylenediamine was prepared which acts as an effective fluorescent sensor for Al3+ with ca. 9.0 fold enhancement in fluorescence intensity and detection limit 10-4.3 M. L can quite clearly distinguish Al3+ over other metal ions Zn2+, Hg2+, Cd2+, Pb2+, Mn2+, Mg2+, Co2+, Ni2+, Cu2+, Ca2+, K+, Li+, Na+ and Fe3+. Cyclic voltammogram and square wave voltammogram of L shows a significant change on interaction with Al3+. Spectroscopic data and DFT calculations confirm 1:1 interaction between L and Al3+ which is reversible with respect to Na2EDTA.

Condensation Product of p-anisaldehyde and L-phenylalanine: Fluorescent "on-off" Sensor for Cu2+ and IMPLICATION Logic Gate.

(Z)-2-(4-methoxybenzylideneamino)-3-phenylpropanoic acid (L) synthesized by condensation of p-anisaldehyde and L-phenylalanine acts as selective fluorescent as well as voltammetric sensor for Cu2+ in 2:1 (v/v) CH3OH:H2O. The fluorescence intensity of L (λmax 425 nm) is quenched ca. 65% by Cu2+. Metal ions - Li+, Na+, K+, Al3+, Cu2+, Zn2+, Cd2+, Hg2+, Mn2+, Ni2+ and Pb2+ do not interfere. The binding constant and the detection limits were calculated to be 0.56 × 102 M-1 and 10-6 M respectively. DFT and TDDFT calculations confirmed 2:1 binding stoichiometry between L and Cu2+ obtained from fluorescence data. The interaction between L and Cu2+ is reversible for many cycles with respect to ethylenediamine tetraacetate anion (EDTA2-) which results in IMPLICATION logic gate.

Schiff Base Derived from 4,4'-methylenedianiline and p-anisaldehyde: Colorimetric Sensor for Cu2+, Paper Strip Sensor for Al3+ and Fluorescent Sensor for Pb2.

The condensation product (L) of 4,4'-methylenedianiline and p-anisaldehyde acts as colorimetric sensor for Cu2+ and Pb2+ ions. On interaction with Cu2+, ethanolic solution of L changes its color to brown while it becomes light pink on interaction with Pb2+. Interaction of Al3+ with L coated paper strip emits bright blue fluorescence. Metal ions like Mg2+, Cu2+, Li+, K+, Na+, Mn2+, Al3+, Hg2+, Co2+, Pb2+, Ni2+, Cd2+, Zn2+, Fe3+ do not interfere the paper strip sensor. The fluorescent intensity of L in ethanol is quenched 25 times by Pb2+ ion. The interaction between L and Pb2+ is reversible and the detection limit of Pb2+ is 10-6 M. The binding constant and stoichiometry of binding between L and Pb2+ was calculated to be 104.8 and 1:2. Theoretical calculations show that the binding of the metal ions to L are favorable and the fluorescence of L is due to π → π* transition.

Condensation Product of 4-Methoxybenzaldehyde and Ethylenediamine: "Off-On" Fluorescent Sensor for Cerium(III).

The condensation product (L) of 4-methoxybenzaldehyde and ethylenediamine has been synthesised and characterised. L showed a 21 times enhancement in fluorescence intensity on interaction with Ce3+ in CH3OH at λmax = 360 nm when excited with 270 nm photons. Metal ions K+, Na+, Al3+, Co2+, Hg2+, Cd2+, Ni2+, Zn2+, Mn2+, Mg2+ and Ca2+ do not interfere. The stoichiometry of binding and the binding constants were determined from spectroscopic data and found to be 1:1 and 104.8 M respectively. The detection limit was found to be 10-5.2 M. The protonation/de-protonation of water molecules coordinated to Ce3+ was found to show interesting behaviour on the fluorescence of L:Ce3+.

Electromagnetic Charge Radius of the Pion at High Precision.

We present a determination of the pion charge radius from high precision data on the pion vector form factor from both timelike and spacelike regions, using a novel formalism based on analyticity and unitarity. At low energies, instead of the poorly known modulus of the form factor, we use its phase, known with high accuracy from Roy equations for ππ elastic scattering via the Fermi-Watson theorem. We use also the values of the modulus at several higher timelike energies, where the data from e^{+}e^{-} annihilation and τ decay are mutually consistent, as well as the most recent measurements at spacelike momenta. The experimental uncertainties are implemented by Monte Carlo simulations. The results, which do not rely on a specific parametrization, are optimal for the given input information and do not depend on the unknown phase of the form factor above the first inelastic threshold. Our prediction for the charge radius of the pion is r_{π}=(0.657±0.003) fm, which amounts to an increase in precision by a factor of about 2.7 compared to the Particle Data Group average.

Microneedle-assisted transdermal delivery of Zolmitriptan: effect of microneedle geometry, in vitro permeation experiments, scaling analyses and numerical simulations.

OBJECTIVE: The present study was aimed to investigate the effect of salient microneedle (MN) geometry parameters like length, density, shape and type on transdermal permeation enhancement of Zolmitriptan (ZMT). METHODS: Two types of MN devices viz. AdminPatch® arrays (ADM) (0.6, 0.9, 1.2 and 1.5 mm lengths) and laboratory fabricated polymeric MNs (PM) of 0.6 mm length were employed. In the case of PMs, arrays were applied thrice at different places within a 1.77 cm2 skin area (PM-3) to maintain the MN density closer to 0.6 mm ADM. Scaling analyses was done using dimensionless parameters like concentration of ZMT (Ct/Cs), thickness (h/L) and surface area of the skin (Sa/L2). RESULTS: Micro-injection molding technique was employed to fabricate PM. Histological studies revealed that the PM, owing to their geometry/design, formed wider and deeper microconduits when compared to ADM of similar length. Approximately 3.17- and 3.65-fold increase in ZMT flux values were observed with 1.5 mm ADM and PM-3 applications when compared to the passive studies. Good correlations were observed between different dimensionless parameters with scaling analyses. Numerical simulations, using MATLAB and COMSOL software, based on experimental data and histological images provided information regarding the ZMT skin distribution after MN application. DISCUSSION: Both from experimental studies and simulations, it was inferred that PM were more effective in enhancing the transdermal delivery of ZMT when compared to ADM. CONCLUSIONS: The study suggests that MN application enhances the ZMT transdermal permeation and the geometrical parameters of MNs play an important role in the degree of such enhancement.

Lidocaine-loaded fish scale-nanocellulose biopolymer composite microneedles.

Microneedle (MN) technology has emerged as an effective drug delivery system, and it has tremendous potential as a patient friendly substitute for conventional methods for transdermal drug delivery (TDD). In this paper, we report on the preparation of lidocaine-loaded biodegradable microneedles, which are manufactured from fish scale-derived collagen. Lidocaine, a common tissue numbing anaesthetic, is loaded in these microneedles with an aim of delivering the drug with controlled skin permeation. Evaluation of lidocaine permeation in porcine skin has been successfully performed using Franz diffusion cell (FDC) which has shown that the drug permeation rate increases from 2.5 to 7.5% w/w after 36 h and pseudo steady state profile is observed from 5.0 to 10.0% w/w lidocaine-loaded microneedle. Swelling experiments have suggested that the microneedles have negligible swellability which implies that the patch would stick to the tissue when inserted. The experiments on MN dissolution have depicted that the lidocaine loaded in the patch is lower than the theoretical loading, which is expected as there can be losses of the drug during initial process manufacture.

Effect of Microneedle Type on Transdermal Permeation of Rizatriptan.

The present study was aimed to investigate the effect of salient microneedle (MN) geometry parameters like length, density, shape and type on transdermal permeation of rizatriptan (RIZ). Studies were carried out using two types of MN devices viz. AdminPatch® arrays (ADM) (0.6, 0.9, 1.2 and 1.5 mm lengths) and laboratory-fabricated polymeric MNs (PMs) of 0.6 mm length. In the case of the PMs, arrays were applied three times at different places within a 1.77-cm2 skin area (PM-3) to maintain the MN density closer to 0.6 mm ADM. Histological studies revealed that PM, owing to their geometry/design, formed wider and deeper microconduits when compared to ADM of similar length. Approximately 4.9- and 4.2-fold increases in the RIZ steady-state flux values were observed with 1.5 mm ADM and PM-3 applications when compared to the passive studies. A good correlation between different dimensionless parameters like the amount of RIZ permeated (C t /C s), thickness (h/L) and surface area (S a/L 2) of the skin was observed with scaling analyses. Numerical simulations provided further information regarding the distribution of RIZ in MN-treated skin after application of different MNs. Overall, the study suggests that MN application enhances the RIZ transdermal permeation and the geometrical parameters of MNs play an important role in the degree enhancement.

Condensation Product of Phenylalanine and Salicylaldehyde: Fluorescent Sensor for Zn(2.).

The condensation product of phenylalanine and salicylaldehyde (L) was synthesised and characterised which was found to be selective fluorescent "off-on" sensor for Zn(2+) ion with the detection limit 10(-5) M. The sensor is free of interferences from metal ions - Na(+), K(+), Al(3+), Mn(2+), Co(2+), Ni(2+), Cu(2+), Pb(2+), Cd(2+) and Hg(2+). The Fluorescence and the UV/visible spectral data reveals a 1:1 interaction between the sensor and Zn(2+) ion with binding constant 10(8). The DFT and TDDFT calculations confirm the structures of the sensor and the sensor-Zn(2+) complex.

Purification and Characterization of Nk-3FTx: A Three Finger Toxin from the Venom of North East Indian Monocled Cobra.

Snake venom three finger toxins (3FTxs) are a non-enzymatic family of venom proteins abundantly found in elapids. We have purified a 7579.5 ± 0.591 Da 3FTx named as Nk-3FTx from the venom of Naja kaouthia of North East India origin. The primary structure was determined by a combination of N-terminal sequencing and electrospray ionization liquid chromatography-mass spectrometry/mass spectrometry. Biochemical and biological characterization reveal that it is nontoxic to human cell lines and exhibit mild anticoagulant activity when tested on citrated human plasma. Nk-3FTx was found to affect the compound action potential (CAP) and nerve conduction velocity of isolated toad sciatic nerve. This is the first report of a non-conventional 3FTx from Naja kaouthia venom that reduces CAP for its neurotoxic effect. Further studies can be carried out to understand the mechanism of action and to explore its potential therapeutic application.

Glucose diffusivity in cell-seeded tissue engineering scaffolds.

OBJECTIVE: To determine the effective glucose diffusion coefficient in cell-seeded porous scaffolds to understand the importance of nutrient diffusion in tissue engineering bioreactors. RESULTS: Cell growth changed the morphological structure of the scaffolds decreasing the effective pore space and, inevitably, decreasing the effective glucose diffusivity in the chosen scaffolds, namely, collagen, poly(L-lactide) and poly(caprolactone) scaffolds from 3.7 × 10(-9) to 3.2 × 10(-9) m(2)/s, 1.4 × 10(-10) to 9.1 × 10(-11) m(2)/s and 1.8 × 10(-10) to 1.3 × 10(-10) m(2)/s, respectively. CONCLUSIONS: The presence of cells over time during cell culture reduces the mobility of glucose. The results can predict the glucose concentration profiles in thick engineered tissues.

Application of Microneedle Arrays for Enhancement of Transdermal Permeation of Insulin: In Vitro Experiments, Scaling Analyses and Numerical Simulations.

The aim of this investigation is to study the effect of donor concentration and microneedle (MN) length on permeation of insulin and further evaluating the data using scaling analyses and numerical simulations. Histological evaluation of skin sections was carried to evaluate the skin disruption and depth of penetration by MNs. Scaling analyses were done using dimensionless parameters like concentration of drug (C t/C s), thickness (h/L) and surface area of the skin (S a/L (2)). Simulation studies were carried out using MATLAB and COMSOL software to simulate the insulin permeation using histological sections of MN-treated skin and experimental parameters like passive diffusion coefficient. A 1.6-fold increase in transdermal flux and 1.9-fold decrease in lag time values were observed with 1.5 mm MN when compared with passive studies. Good correlation (R (2) > 0.99) was observed between different parameters using scaling analyses. Also, the in vitro and simulated permeations profiles were found to be similar (f 2 ≥ 50). Insulin permeation significantly increased with increase in donor concentration and MN length (p < 0.05). The developed scaling correlations and numerical simulations were found to be accurate and would help researchers to predict the permeation of insulin with new dimensions of MN in optimizing insulin delivery. Overall, it can be inferred that the application of MNs can significantly enhance insulin permeation and may be an efficient alternative for injectable insulin therapy in humans.