METHOD DEVELOPMENT AND VALIDATION FOR THE SIMULTANEOUS ESTIMATION OF ASCORBIC ACID AND FOLIC ACID VITAMINS BY REVERSE-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY METHOD IN CYANOBACTERIAL METABOLITES AND NUTRACEUTICAL FORMULATION

Objective: It was aimed to estimate ascorbic acid (ASC) and folic acid (FLC) in cyanobacterial metabolite by the reverse-phase high-performanceliquid chromatography (RP-HPLC) method, and the work was also extended to nutraceutical formulation.Methods: RP-HPLC method were developed for simultaneous estimation of two vitamins ASC and FLC in cyanobacterial metabolite and nutraceuticalusing isosbestic point at wavelength 280 nm. Method was selected after calculating system suitability and validated as per ICH guidelines.Results: The developed analytical method parameters found within limits prescribed by ICH and USP guidelines. The retention time was found to be2.334 and 3.892, respectively, for ASC and FLC. Limit of detection and limit of quantification for ASC and FLC were found to be 0.087 and 0.263 µg/ml,0.052 and 0.159 µg/ml, respectively. Recovery studies show that method is capable of recovering analytes from its formulation. The method is meetingthe criteria for validation as per the guidelines.Conclusion: The method is simple, precise, specific, and accurate. The newly developed method can be used in pharmaceutical industry for routineanalysis of ASC and FLC in tablet dosage form.Keywords: Cyanobacteria, Nutraceutical, Reverse-phase high-performance liquid chromatography, Ascorbic acid, Folic acid, Vitamins, Metabolites

Prediction of Task-Related BOLD fMRI with Amplitude Signatures of Resting-State fMRI

Blood oxygen contrast-functional magnetic resonance imaging (fMRI) signals are a convolution of neural and vascular components. Several studies indicate that task-related (T-fMRI) or resting-state (R-fMRI) responses linearly relate to hypercapnic task responses. Based on the linearity of R-fMRI and T-fMRI with hypercapnia demonstrated by different groups using different study designs, we hypothesized that R-fMRI and T-fMRI signals are governed by a common physiological mechanism and that resting-state fluctuation of amplitude (RSFA) should be linearly related to T-fMRI responses. We tested this prediction in a group of healthy younger humans where R-fMRI, T-fMRI, and hypercapnic (breath hold, BH) task measures were obtained form the same scan session during resting state and during performance of motor and BH tasks. Within individual subjects, significant linear correlations were observed between motor and BH task responses across voxels. When averaged over the whole brain, the subject-wise correlation between the motor and BH tasks showed a similar linear relationship within the group. Likewise, a significant linear correlation was observed between motor-task activity and RSFA across voxels and subjects. The linear rest–task (R–T) relationship between motor activity and RSFA suggested that R-fMRI and T-fMRI responses are governed by similar physiological mechanisms. A practical use of the R–T relationship is its potential to estimate T-fMRI responses in special populations unable to perform tasks during fMRI scanning. Using the R–T relationship determined from the first group of 12 healthy subjects, we predicted the T-fMRI responses in a second group of 7 healthy subjects. RSFA in both the lower and higher frequency ranges robustly predicted the magnitude of T-fMRI responses at the subject and voxel levels. We propose that T-fMRI responses are reliably predictable to the voxel level in situations where only R-fMRI measures are possible, and may be useful for assessing neural activity in task non-compliant clinical populations

Statistical Learning for Resting-State fMRI: Successes and Challenges

International audienceIn the absence of external stimuli, fluctuations in cerebral activity can be used to reveal intrinsic structures. Well-conditioned probabilistic models of this so-called resting-state activity are needed to support neuroscientific hypotheses. Exploring two specific descriptions of resting-state fMRI, namely spatial analysis and connectivity graphs, we discuss the progress brought by statistical learning techniques, but also the neuroscientific picture that they paint, and possible modeling pitfalls

Importance of nutrient loading and irrigation in gross primary productivity trends in India

Investigating the effects of various environmental factors on gross primary productivity (GPP) is crucial for quantifying the carbon exchange between the atmosphere and the terrestrial vegetation for managing climate change. Although it is well known that various natural and anthropogenic factors (e.g., climate change, agricultural activities, and atmospheric CO2 concentration change) can alter GPP, their relative influences are not clearly understood in every region. In this study, we consider several factors and investigate their roles in increasing the GPP in large parts of India. We considered about three decades (1980s to late 2000s) of GPP data and use a regression based systematic approach to find out the most likely cause explaining the trends in India. This study suggests that the common suspects like CO2 and climate may have limited influence on the GPP trends in India when compared to anthropogenic influences. Our results instead support the notion that GPP trends in India are mainly shaped by agricultural activities through nutrient loading (R2=0.68) and irrigation (R2=0.1). Overall, our study reveals the potential of agricultural activities in altering the carbon budget of a region. © 2020 Elsevier B.V

Bronchoprotective effect of Zingiber officinale roscoe (Ginger) in guinea pigs

Background: To evaluate the bronchoprotective effect of aqueous extract of Zingiber officinale (AZO) in guinea pigs and compare the same with that of standard drugs.Methods: Guinea pigs of either sex weighing between 350 to 450 Grams were randomly divided into 13 groups, each group containing 6 animals. Bronchospasm was induced by placing guinea pigs in histamine exposition chamber and exposing them to either 0.25% of histamine acid phosphate or 10% acetyl choline through a nebuliser under 40mm Hg pressure. The time for development of asphyxia was noted. After two and half hours, the animals were administered orally with vehicle / drugs as per the following: Gr I- Normal saline 1ml/100 Grams, Gr II- Salbutamol 1.6mg/kg, Gr III- Chlorpheniramine maleate 0.8mg/kg, Gr IV to Gr VI- AZO 200, 400, and 800mg/kg, Gr VII- AZO 200mg/kg and Salbutamol 0.8mg/kg. For acetylcholine-induced Bronchospasm Gr III animals received atropine 2mg/kg and Gr VII was not taken, rest others remaining the same. After 1 hour of treatment, the animals were again exposed to histamine or acetyl choline aerosol. The exposition time for each animal was again noted and mean increase or decrease in exposition time were noted. The data were subjected to stastical analysis by using paired ‘t’ test. Percentage of protection was also calculated.Results: AZO at all the doses studied (except 200mg/kg), showed highly significant increase in exposition time against histamine-induced bronchospasm. Combination of AZO (200mg/kg) with salbutamol (0.8mg/kg) also produced augmented effect. But against Acetylcholine induced bronchospasm, AZO did not produce any significant protective effect at any of the doses.Conclusions: AZO produced significant dose dependant bronchoprotection against histamine induced bronchospasm which might be due to antihistaminic action

Stochastic neural network model for spontaneous bursting in hippocampal slices

A biologically plausible, stochastic, neural network model that exhibits spontaneous transitions between a low-activity ͑normal͒ state and a high-activity ͑epileptic͒ state is studied by computer simulation. Brief excursions of the network to the high-activity state lead to spontaneous population bursting similar to the behavior observed in hippocampal slices bathed in a high-potassium medium. Although the variability of interburst intervals in this model is due to stochasticity, first return maps of successive interburst intervals show trajectories that resemble the behavior expected near unstable periodic orbits ͑UPOs͒ of systems exhibiting deterministic chaos. Simulations of the effects of the application of chaos control, periodic pacing, and anticontrol to the network model yield results that are qualitatively similar to those obtained in experiments on hippocampal slices. Estimation of the statistical significance of UPOs through surrogate data analysis also leads to results that resemble those of similar analysis of data obtained from slice experiments and human epileptic activity. These results suggest that spontaneous population bursting in hippocampal slices may be a manifestation of stochastic bistable dynamics, rather than of deterministic chaos. Our results also question the reliability of some of the recently proposed, UPO-based, statistical methods for detecting determinism and chaos in experimental time-series data