24 research outputs found
A Novel Class of Pyrazoline Analogue of Combretastatin-A4 (CA-4): Synthesis Characterization and in-vitro Biological Testing
A series of pyrazoline bridged combretastatin analogues were designed and synthesised from their precursor chalcone analogues, and all these compounds were ascertained by IR, 1H NMR, and mass spectral analysis. Subsequently, all these compounds were evaluated for anticancer activities against breast cancer (MCF-7) and normal Vero (Monkey Kidney) cell lines, and five selected compounds from the series were evaluated against Hela (Human Cervical), MDA-MB-231 (Breast), and A-549 (Lung cancer) cell lines using the Sulforhodamine B (SRB) assay method. Compounds 3a, 6a, 6e, 5b, 7a, 5a, and 7d were found to be the most potent in the series, with a GI50 value of 10 to 30 M in the MCF-7 cell line. Moreover, the same compounds 6a and 7a showed remarkable cytotoxicity against the A-549 (Lung) cell line with a GI50 value ranging from 10 to 30 M, while compound 3a displayed moderate cytotoxicity against the Hela (Human Cervical) cell line. All these compounds were found nontoxic to the Vero (Monkey Kidney) normal cell line
Potassium phosphate catalyzed highly efficient synthesis of structurally diverse thioethers at ambient temperature
154-158Commercially available potassium phosphate has been demonstrated to be a highly efficient catalyst for the synthesis of
thioethers employing two different routes viz. alkylation of thiols with alkyl/aralkyl halides and by Michael addition of thiols
to conjugated alkenes
Intracranial hypotension secondary to spinal arachnoid cyst rupture presenting with acute severe headache: a case report
<p>Abstract</p> <p>Introduction</p> <p>Headache is a common presenting complaint and has a wide differential diagnosis. Clinicians need to be alert to clues that may suggest an underlying secondary aetiology. We describe a novel case of headache secondary to intracranial hypotension which was precipitated by the rupture of a spinal arachnoid cyst.</p> <p>Case report</p> <p>A 51-year-old Indian female presented with sudden onset severe headache suggestive of a subarachnoid haemorrage. Investigations including a computed tomography brain scan, cerebrospinal fluid examination and a magnetic resonance angiogram were normal. The headache persisted and magnetic resonance imaging revealed bilateral thin subdural collections, a spinal subarachnoid cyst and a right-sided pleural effusion. This was consistent with a diagnosis of headache secondary to intracranial hypotension resulting from spinal arachnoid cyst rupture.</p> <p>Conclusions</p> <p>Spinal arachnoid cyst rupture is a rare cause of spontaneous intracranial hypotension. Spontaneous intracranial hypotension is a common yet under-diagnosed heterogeneous condition. It should feature significantly in the differential diagnosis of patients with new-onset daily persistent headache.</p
DESIGN AND DEVELOPMENT OF A COMPACT 1:4 UNEQUAL WILKINSON POWER DIVIDER USING COAXIAL CABLES FOR VHF RADAR APPLICATIONS
This article presents a novel implementation of compact Unequal Wilkinson Power Divider (UWPD) designed for the power split ratio (PSR) of 1: 4 using series and parallel combinations of the coaxial cables. This arrangement results in a very compact power divider for Very High Frequency (VHF) applications, has good matching at all the ports, very good amplitude balance, desired relative phase difference and isolation between the output ports. With proper choice of the cables, the proposed method of implementation is capable of handling high power with low insertion loss. Besides, by merely trimming the length of the coaxial cable the fine frequency tuning and phase equalization can be easily accomplished, this is not easy with its microstrip line configuration once its printed circuit board (PCB) fabrication process is carried out. Furthermore, the reduction up to 78.84% has been achieved in the length of quarterwave line in the proposed 1: 4 UWPD as compared to that of its respective conventional design footprint, with potential for the further miniaturization due to the use of the flexible coaxial cables. For the fabricated compact power divider the simulated and measured results are found in good agreement. ©2019 by Begell House, Inc
Effect of spatial correlation on regional trends in rain events over India
The regional trends are evaluated in the frequency of various rain events using the daily gridded (1° × 1°) rainfall dataset for the time period 1901–2004, prepared by the India Meteorological Department (IMD). In terms of intensity, the events are classified as low, moderate, heavy and extreme heavy, while short and long spells are classified on the basis of duration of rainfall. The analytical (parametric) and the empirical (bootstrap) techniques were used to incorporate the impact of spatial correlation in regional trends. It is observed that, consideration of spatial correlation reduces the significance level of the trends and the effective number of grid points falling under each category. Especially, the noticeable cross-correlation have reduced the significance of the trends in moderate and long spell rain events to a large extent, while the significance of trends in the extreme heavy and short spell events is not highly affected because of small cross-correlation
A neurocomputing approach to predict monsoon rainfall in monthly scale using SST anomaly as a predictor
A relationship between summer monsoon rainfall and sea surface temperature anomalies was investigated with the aim of predicting the monthly scale rainfall during the summer monsoon period over a section (80°–90°E, 14°–24°N) of eastern India that depends heavily upon the rainfall during the summer monsoon months for its agricultural practices. The association between area-averaged rainfall of June over the study zone and global sea surface temperature (SST) anomalies for the period 1982–2008 was examined and the variability of rainfall in monthly scale was calculated. With a view to significant variability in the rainfall in the monthly scale, it was decided to implement the artificial neural network (ANN) for forecasting the monthly scale rainfall using the SST anomalies as a predictor. Finally, the potential of ANN in this prediction has been assessed
Skill of monthly rainfall forecasts over India using multi-model ensemble schemes
Rainfall in the month of July in India is decided by large-scale monsoon pattern in seasonal to interannual timescales as well as intraseasonal oscillations. India receives maximum rainfall during July and August. Global dynamic models (either atmosphere only or coupled models) have varying skills in predicting the monthly rainfall over India during July. Multi-model ensemble (MME) methods have been utilized to evaluate the skills of five global model predictions for 1982–2004. The objective has been to develop a prediction system to be used in real time to derive the mean of the forecast distribution of monthly rainfall. It has been found that the weighted multi-model ensemble (MME) schemes have higher skill in predicting July rainfall compared to individual models. Through the MME methods, skill of rainfall predictions improved significantly over eastern parts of India. However, there is a region over India where none of the models or the MME scheme has any useful skill. Similarly, there are few typical years in which the mean distribution of July rainfall cannot be predicted with higher skill using the available statistical post-processing methods. A simple MME probabilistic scheme has been utilized to show that skill of probabilistic predictions improved when the representation of mean of forecast distribution has better skill
Characteristic changes in the long and short spells of different rain intensities in India
In this paper, changes in the long and short spells of different rain intensities are statistically analyzed using daily gridded rainfall data prepared by the India Meteorological Department for the period 1951–2008. In order to study regional changes, analyses have been conducted over nine selected agro-meteorological (agro-met) divisions, five homogeneous zones, and also over the whole of India. Rain events of different intensities with continuous rainfall of more than or equal to 4 days are classified here as long spells. Those with less than 4 days are termed as short spells. Those results which are statistically significant at 95% confidence level are discussed in this paper. Trend analysis shows that during the summer monsoon months of June to September, short spell rain events with heavy intensity have increased over India as a whole. On the other hand, long spell rain events with moderate and low intensities have decreased in numbers. Results further show that the contributions of long spell moderate and short spell low-intensity rain events to the total rainfall have decreased whereas the contributions of short spell heavy and moderate-intensity rain events to the total seasonal rainfall have increased. Percentage changes in various categories of long and short spells in the decade 1991–2000 compared with the earlier decade 1951–1960, highlight the maximum increase in heavy-intensity short spell category and decrease in moderate-intensity long spell category in India as a whole and in most of the homogeneous zones and agro-met divisions. The changes in different types of rain events differ in the six homogeneous zones and nine selected agro-met divisions. However, in three homogeneous zones and three agro-met divisions, the short spell heavy-intensity rain events dominate as in the entire country. There are also changes observed in the monthly occurrences of above categories of rain events during the 4 months of summer monsoon. Such results with details of changes in rain categories in different parts of India have important implications in agriculture sector in the country
Potassium phosphate catalyzed highly efficient synthesis of structurally diverse thioethers at ambient temperature
Commercially available potassium phosphate has been demonstrated to be a highly efficient catalyst for the synthesis of thioethers employing two different routes viz. alkylation of thiols with alkyl/aralkyl halides and by Michael addition of thiols to conjugated alkenes