Homologation of alpha-amino acids to beta-amino acids using Boc(2)O

The use of Boc(2)O as a coupling agent in the homologation of N-urethane protected-alpha-amino acid to its beta-homomers by the Arndt-Eistert method is described. The homologation gives good yields without racemization. The use of Boc(2)O as a coupling agent not only allows the easy scale up of the process but also it is cost effective

Synthesis of beta-amino acids: 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (TBTU) for activation of Fmoc-/Boc-/Z-alpha-amino acids

A new and efficient method for the homologation of urethane protected alpha-amino acids to its beta-homomers by the Arndt-Eistert method using TBTU as a coupling agent is described. Several Fmoc-/Boc-/Z-protected alpha-amino diazoketone derivatives have been obtained as crystalline solids in good yield. The method is found to be rapid and stereospecific

Different Approaches for Speaker Diarization

Audio diarization is the process of annotating an input audio channel with information that attributes (possibly overlapping) temporal regions of signal energy to their specific sources. These sources can include particular speakers, music, background noise sources and other signal source/channel characteristics. Speaker diarization is the task of determining “who spoke when?†in an audio or video recording that contains an unknown amount of speech and also an unknown number of speakers. Diarization can be used for helping speech recognition, facilitating the searching and indexing of audio archives and increasing the richness of automatic transcriptions, making them more readable. Over recent years, however, speaker diarization has become an important key technology for many tasks, such as navigation, retrieval or higher-level inference on audio data. Accordingly, many important improvements in accuracy and robustness have been reported in the area of conferences. The application domains, from broadcast news, to lectures and meetings, vary greatly and pose different problems, such as access to multiple microphones and multimodal information or overlapping speech

Microwave assisted Wolff rearrangement: A facile method for the synthesis of Fmoc-β-amino acids

The Wolff rearrangement of α-diazoketones, derived from Fmoc-α-amino acids, under no base conditions on exposure to microwave irradiation for 40 to 60 sec to Fmoc-β-amino acids with retention of configuration in good yield (91-95%) is described

Biochemical Evaluation of Cotton Genotypes using Soluble Protein, Esterase (EST), Peroxidase (POX) And Polyphenol Oxidase (PPO) and their Role in Plant Disease Resistance

Isozyme analysis is a powerful biochemical technique that has numerous applications in plant biology. It has long been used by geneticists to study the population genetics.  The isozyme esterase, peroxidase and polyphenol oxidase were standardized for upland cotton (Gossypium hirsutum L.) germplasm lines collected from all over the country.  The knowledge of nature and magnitude of genetic diversity present in the germplasm is most important pre-requisite for the success of any breeding program. The thirty-four cotton germplasm lines were screened for prime three isozymes based on quantification assay and qualitative PAGE profiling. Among the material, the genotype AKH – 24 (190.60 mg ml-1), AKH – 053 (189.42 mg ml-1) and VIKAS (184.53 mg ml-1) recorded high protein content, whereas the enzymatic activities of esterase, peroxidase and polyphenol oxidase exhibited remarkable differences along with the protein content. The genotype LRA–5166 exhibited high esterase (462.68 mM mg protein-1 min-1) and peroxidase activity (250.97mM mg protein-1 min-1), while AKH – 24 recorded the maximum polyphenol oxidase activity (131.45 mM mg protein-1min-1).  The banding pattern of biochemical markers revealed that the maximum number of bands were recorded in esterase analysis (fifteen) followed by protein (twelve) whereas, only five bands each were detected in peroxidase and polyphenol oxidase analysis indicating limited polymorphism.  The Relative Mobility (Rm) values were ranged from 0.083 to 0.883 (protein), 0.100 to 0.971 (esterase), 0.033 to 0.283 (peroxidase) and 0.048 to 0.206 (polyphenol oxidase).  The present study demonstrated that cotton genotypes could be differentiated by their quantity and quality through electrophoretic banding profiles. These results could be of practical value for cultivar identification, purity testing along with associated prediction of pest and disease resistance.  However, the major constraint is that these biochemical markers do not able to reproduce the similar kind of variation pattern, but can provide strong distinguishing polymorphism each time

Evaluation of Wound Healing Activity of Angiotensin Converting Enzyme Inhibitors in Wistar Rats

Angiotensin converting enzyme (ACE) inhibitors are known to increase the level of bradykinin by preventing its breakdown and also promote prostaglandin synthesis by direct and indirect methods which in turn may promote wound healing. However there is paucity of scientific information in this regard. Therefore in the present study we have investigated the effect of ACE inhibitors like Captopril and Enalapril on different wound models in Wistar rats. Excision, resutured incision and dead space wounds were inflicted in male Wistar rats under light ether anaesthesia, taking aseptic precautions. Control animals received vehicle and other groups received Captopril (10mg/kg) and Enalapril (10mg/kg) orally for a period of 10 days in incision and dead space wound models, whereas similar treatments were continued in excision wound models till complete closure of wounds. On the 11th day, after estimating breaking strength of resutured incision wounds (under anaesthesia), granulation tissue was removed from dead space wounds to estimate breaking strength, hydroxyproline content as well as quantification of granulation tissue and histological studies were carried out in control and treated groups. Captopril and Enalapril significantly increased the rate of wound healing, reduced the number of days required for complete epithelialization and final area of scar in excision wounds. Both the ACE inhibitors significantly increased breaking strength of resutured incision wounds and granulation tissue. Also these two drugs significantly enhanced both granulation tissue formation and granulation tissue hydroxyproline content. Histological studies confirmed these findings. Captopril and Enalapril significantly promoted the healing process in all the three wound models studied. These results indicate the wound healing property of ACE inhibitors and clinical studies in this regard are worthwhile

Design of ECG Acquisition System and Noise Removal Using MSP 430 Controller

In today’s world, electrocardiography (ECG) is very important to detect heart related problems. Many technologies have been developed for medical monitoring. In this study, we are developing monitoring system using 3 leads. This system takes input as an analog signal processes and conditions it and converts it into digital signal. After converting, it processes the digital signal with MSP430 controller

Nanocrystalline MoBi2Se5 Ternary Mixed Metal Chalcogenide Thin-films for Solar Cell Applications

AbstractOptical, structural, morphological and photoelectrochemical properties were investigated of ternary MoBi2Se5 thin film prepared by simple arrested precipitation technique (APT). The precursors used were molybdenum, bismuth, triethanolamine complexes (TEA) along with organic additives. Ammonium molybdate, Bismuth nitrate and sodium selenosulphite were used as sources of Mo4+, Bi3+ and Se2− ions. The optical band gap of thin film was estimated to be 1.78eV. X-ray diffraction data reveals that the grown MoBi2Se5 thin film was highly nanocrystalline with orthorhombic structure. Scanning electron microscopy studies reveal that porous layer having elongated fibrous morphology with high surface area. The film was obtained with a well-defined composition, very close to the expected one. PEC application of prepared thin film were checked in Sulphide / Poly sulphide electrolyte which revealed that MoBi2Se5 thin film deposited on FTO coated glass exhibited maximum values of fill factor (FF) and conversion efficiency (η) with n type semiconductor nature

Uracil DNA glycosylase (UDG) activities in Bradyrhizobium diazoefficiens: characterization of a new class of UDG with broad substrate specificity

Repair of uracils in DNA is initiated by uracil DNA glycosylases (UDGs). Family 1 UDGs (Ung) are the most efficient and ubiquitous proteins having an exquisite specificity for uracils in DNA. Ung are characterized by motifs A (GQDPY) and B (HPSPLS) sequences. We report a novel dimeric UDG, Blr0248 (BdiUng) from Bradyrhizobium diazoefficiens. Although BdiUng contains the motif A (GQDPA), it has low sequence identity to known UDGs. BdiUng prefers single stranded DNA and excises uracil, 5-hydroxymethyl-uracil or xanthine from it. BdiUng is impervious to inhibition by AP DNA, and Ugi protein that specifically inhibits family 1 UDGs. Crystal structure of BdiUng shows similarity with the family 4 UDGs in its overall fold but with family 1 UDGs in key active site residues. However, instead of a classical motif B, BdiUng has a uniquely extended protrusion explaining the lack of Ugi inhibition. Structural and mutational analyses of BdiUng have revealed the basis for the accommodation of diverse substrates into its substrate binding pocket. Phylogenetically, BdiUng belongs to a new UDG family. Bradyrhizobium diazoefficiens presents a unique scenario where the presence of at least four families of UDGs may compensate for the absence of an efficient family 1 homologue

Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society