المؤلفون: Vikhrankar SS, Satbhai S, Kulkarni P, Ranbhor R, Ramakrishnan V, Kodgire P

المصدر: Biologics: Targets & Therapy, Vol Volume 18, Pp 165-179 (2024)

مصطلحات موضوعية: chiral amines, biocatalysis, protein engineering, ω-transaminases, sitagliptin, enzyme immobilization, co-factor regeneration, Medicine (General), R5-920

الوصف: Sayali Shantaram Vikhrankar,1 Seema Satbhai,2 Priyanka Kulkarni,2 Ranjit Ranbhor,3 Vibin Ramakrishnan,4 Prashant Kodgire1 1Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, MP, India; 2Sevit Healthcare Private Limited, Pune, MH, India; 3Pergament & Cepeda LLP, Florham Park, NJ, USA; 4Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, IndiaCorrespondence: Ranjit Ranbhor, Pergament & Cepeda LLP, 25A Hanover Road, Florham Park, NJ, 07932, USA, Tel +1 973 967 0490, Email ranjitranbhor@gmail.comAbstract: Chiral amines are essential motifs in pharmaceuticals, agrochemicals, and specialty chemicals. While traditional chemical routes to chiral amines often lack stereoselectivity and require harsh conditions, biocatalytic methods using engineered enzymes can offer high efficiency and selectivity under sustainable conditions. This review discusses recent advances in protein engineering of transaminases, oxidases, and other enzymes to improve catalytic performance. Strategies such as directed evolution, immobilization, and computational redesign have expanded substrate scope and enhanced efficiency. Furthermore, process optimization guided by techno-economic assessments has been crucial for establishing viable biomanufacturing routes. Combining state-of-the-art enzyme engineering with multifaceted process development will enable scalable, economical enzymatic synthesis of diverse chiral amine targets.Keywords: chiral amines, biocatalysis, protein engineering, ω-transaminases, sitagliptin, enzyme immobilization, co-factor regeneration

وصف الملف: electronic resource

العلاقة: https://www.dovepress.com/enzymatic-routes-for-chiral-amine-synthesis-protein-engineering-and-pr-peer-reviewed-fulltext-article-BTTTest; https://doaj.org/toc/1177-5491Test

الوصول الحر: https://doaj.org/article/14f4362d70ed43aa914d28e5abd2af4aTest

المؤلفون: Milanta Tom, Sabu Thomas, Bastien Seantier, Yves Grohens, Mohamed Pulikaparambil Kochaidrew, Ramakrishnan Subramanian, Tapas Ranjan Mohanty, Henri Vahabi, Hanna Joseph Maria, Jibin Keloth Paduvilan, Martin George Thomas

المصدر: eXPRESS Polymer Letters, Vol 18, Iss 6, Pp 638-655 (2024)

مصطلحات موضوعية: natural fiber, reinforcement, renewable resource, elastomer, filler, nanocomposites, natural rubber, nanofiber, rheology, Materials of engineering and construction. Mechanics of materials, TA401-492, Chemical technology, TP1-1185

الوصف: The augmented demand for sustainable nanocomposites has paved the way to explore naturally derived materials. Nanocellulose, with its bountiful sources and inherent properties, ranks top in the list of biofillers with a perspective of reducing the carbon footprint. A systematic study is required to understand the reinforcing effect of various types of nanocellulose. In the present work, we selected three types of nanocellulose, i.e., cellulose nanocrystal (CNC), cellulose nanofiber (CNF) and microfibrillated cellulose (MFC), to investigate the effect of geometrical structure on the properties of unvulcanized natural rubber (NR). Incorporating these fillers improved the tensile strength and modulus of natural rubber films significantly through reinforcement via filler network structure. The reinforcing effect of CNF was found to be higher compared to CNC and MFC, where an increase of 3.85 MPa in tensile strength from the neat sample was obtained. More uniform dispersion was evident through transmission electron microscopy, atomic force microscopy and Raman imaging for CNF in the rubber matrix. The structural properties were determined using Raman spectra and X-ray diffraction. The rheological studies revealed a good interaction between filler and NR. The work presented comprehensively compares different types of nanocellulose as reinforcing filler in NR matrix, which will help the researchers select an ideal type for their specific application and, thus, the proper usage of renewable resources, leading to sustainability and a circular economy.

وصف الملف: electronic resource

العلاقة: http://www.expresspolymlett.com/letolt.php?file=EPL-0012899&mi=cdTest; https://doaj.org/toc/1788-618XTest

الوصول الحر: https://doaj.org/article/30eb8e54a85146e996c676aa840b9d9cTest

المؤلفون: Praveen Kumar Chandra Sekar, Sheena Mariam Thomas, Ramakrishnan Veerabathiran

المصدر: Exploration of Medicine, Vol 5, Iss 3, Pp 384-400 (2024)

مصطلحات موضوعية: cervical cancer, prevention, technological advances, prospects, Other systems of medicine, RZ201-999

الوصف: This article provides an informative overview of the current situation and future trends in cervical cancer prevention. Cervical cancer remains a significant public health concern worldwide and is characterized by notable variations in both incidence and mortality rates between developed and developing countries. This underscores the importance of understanding the pathophysiology of cervical cancer, stressing the involvement of high-risk HPV types. The presence of supplementary risk factors facilitates the transition from infection to cancer. This review examines current preventive methods, including the success of HPV vaccines such as Gardasil and Cervarix, and the effectiveness of screening techniques, from cytology to HPV DNA testing. It noted the limitations faced by primary and secondary preventive measures, particularly in low-resource settings, which include access to vaccines and effective screening procedures. Emerging technologies in cervical cancer prevention, such as liquid-based cytology, molecular testing, and AI, promise to improve early detection and diagnosis accuracy and efficiency. The potential of precision medicine to customize treatment based on individual risk factors was discussed. It explores the innovation in genetic editing techniques, such as CRISPR/Cas9, in targeting HPV oncoproteins, the advent of immunotherapy, the role of tumor-infiltrating lymphocytes, and the prospects of biomarkers in improving early detection. Research and technological advancements are leading to transformative changes in cervical cancer prevention. These developments suggest a path toward improved screening, diagnosis, and treatment that could significantly reduce the global burden of the disease. However, realizing the full potential of these advances requires inclusive research and international collaboration to overcome access disparities, particularly in resource-limited settings.

وصف الملف: electronic resource

العلاقة: https://www.explorationpub.com/Journals/em/Article/1001226Test; https://doaj.org/toc/2692-3106Test

الوصول الحر: https://doaj.org/article/cb100db3ebb549e794ee2017a4e56c2bTest

المؤلفون: Krishnaprabha, V.^{1, 1}, Ramakrishnan, Lalitha¹, Vijayaraghavan, R.², Unnikrishnan, Gayathri³

المصدر: Asian Journal of Dairy and Food Research 43(1):46-52. 2024

المؤلفون: Manoharan Premkumar, Tengku Juhana Tengku Hashim, Sowmya Ravichandran, Tan Ching Sin, Ramakrishnan Chandran, Anas R. Alsoud, Pradeep Jangir

المصدر: Alexandria Engineering Journal, Vol 93, Iss , Pp 90-113 (2024)

مصطلحات موضوعية: ε-based constraint-handling, Energy, FACTS controllers, Flow direction algorithm, Multiobjective optimization, Optimal power flow analysis, Engineering (General). Civil engineering (General), TA1-2040

الوصف: This paper delves into the increasingly complex domain of Optimal Power Flow (OPF) within modern power systems, enhanced by the integration of unpredictable renewable energy sources. The research originally integrates stochastic photovoltaic and wind energy sources, along with a suite of Flexible AC Transmission System (FACTS) components – including thyristor-controlled series compensators, static VAR compensators, and thyristor-controlled phase shifters. The primary objective is to solve the OPF problem by reducing generation costs while accommodating the variable nature of renewable energy sources and load demands. This study prioritizes the examination of both constant and fluctuating load requirements. The inherent variability of PV and wind energy, along with load demand, is captured through the modelling of probability density functions. This approach enables a more detailed optimization process, incorporating not just the cost of thermal energy generation but also the scheduling costs of renewable sources and associated penalty costs. Moreover, the study examines the strategic placement and sizing of FACTS components, an aspect essential in minimizing the overall cost of power production. Employing both single- and multi-objective optimization algorithms, the research addresses the OPF problem in a modified IEEE-30 bus system through various case studies. The application of the recently developed flow direction algorithm, including its multi-objective variant with an ε-based constraint-handling mechanism to OPF problem is the primary contributions of this work. The results, benchmarked against several advanced metaheuristic algorithms, reveal the proposed algorithm's superior performance. This comprehensive study not only underscores the potential of integrating renewable energy sources into the grid but also highlights the efficacy of intelligent optimization strategies in managing the complexities of modern power systems.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S1110016824002084Test; https://doaj.org/toc/1110-0168Test

الوصول الحر: https://doaj.org/article/dc2e3839b07a49d3ac2ef52c0d46da55Test

المؤلفون: GV Vishnupriyasriee, Ravipati Chakradhar, Muralidharan Yuvaraj, Ramakrishnan Karthik Krishna, Pitchandi Muthiah

المصدر: Journal of Clinical and Diagnostic Research, Vol 18, Iss 02, Pp 01-06 (2024)

مصطلحات موضوعية: bronchiectasis, cavity, consolidation, fibrosis, granuloma, pleural effusion, Medicine

الوصف: Introduction: Tuberculosis is a worldwide public health problem associated with high morbidity and mortality. Tuberculosis can manifest in active and latent forms. Improving the diagnosis, treatment, and screening of tuberculosis is crucial for effective tuberculosis control. Chest X-ray and Computed Tomography chest play a vital role in diagnosing and screening for tuberculosis. Aim: To analyse the spectrum of radiological findings in pulmonary tuberculosis. Materials and Methods: The present retrospective descriptive study was conducted at a teritary care hospital in the Department of Radiodiagnosis, Saveetha Medical College and Hospital, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, Tamil Nadu, India. The data of 160 patients diagnosed with pulmonary tuberculosis between January 2019 and December 2020 were accessed and analysed. The recorded variables included forms of pulmonary tuberculosis, age/gender distribution, co-morbidities, Acid-fast Bacillus (AFB) smear status, and radiological findings and distribution. Descriptive statistics are presented in frequency and percentage. Results: Among the 160 cases of pulmonary tuberculosis, 30 (18.75%) cases were active primary tuberculosis, 105 (65.63%) cases were active post-primary tuberculosis, and 25 (15.62%) cases were inactive tuberculosis. Among the 30 cases of active primary tuberculosis, 14 (46.67%) cases had consolidation with air bronchogram, and 6 (20%) cases had consolidation without air bronchogram. Among the 105 cases of active post-primary tuberculosis, 65 (61.9%) cases had consolidation, 50 (47.62%) cases had cavities, and 56 (81.9%) cases had centrilobular nodules with a tree-in-bud appearance. Among the 25 cases of inactive tuberculosis, 18 (72%) cases had fibrosis with bronchiectasis, while 4 (16%) cases had fibrosis without bronchiectasis, and 3 (12%) cases had calcified granulomas. Conclusion: The study conclusively demonstrates the diverse radiological manifestations of pulmonary tuberculosis in different patient demographics. It highlights a higher incidence of active post-primary tuberculosis, especially in patients above 45 years, with varying radiological findings such as consolidation, cavitation, and fibrosis.

وصف الملف: electronic resource

العلاقة: https://www.jcdr.net/articles/PDF/19037/67334_CETest[Ra1]_F(SHU)_QC(SHK_RDW_SHU)_PF1(VD_DK)_PFA(VD_KM)_PN(KM).pdf; https://doaj.org/toc/2249-782XTest; https://doaj.org/toc/0973-709XTest

الوصول الحر: https://doaj.org/article/3105ca8f14c048d890ec41c8e58eac63Test

المؤلفون: Vineeta Sharma, Samiya Baby, Sukhveer Singh, Deepak Kumar Sachan, Abhishek Mishra, Aditya Bhushan Pant, Ramakrishnan Parthasarathi, Vikas Srivastava

المصدر: The Microbe, Vol 3, Iss , Pp 100061- (2024)

مصطلحات موضوعية: Spike proteins, Nucleocapsid Proteins, Variants, Phylogenetic Analysis and SARS-CoV-2, Microbiology, QR1-502

الوصف: The rapid emergence of genetic variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) after late 2020, lead to origin of the term “variant of concern” and became the prime issue for the health of the human populations across the globe. Genome surveillance provides the information about the functional consequences of the variants and their divergence. Presently, we report and compare the nucleotide sequences of the isolated SARS-CoV-2 genomes at two different time-frame i.e. first wave (June- September, 2020) and second wave (April-May, 2021) from Lucknow, Uttar Pradesh, India. We employed the Oxford Nanopore MINION system and ARTIC protocol for sequencing, achieving >90x genome coverage in approximately 90% of samples. Increased mutation density in viral spike proteins were the cause of higher transmission and infectivity of second wave. The second wave exhibited a higher mutation density in viral spike proteins, likely contributing to increased transmission and infectivity. Notable spike mutations included receptor-binding domain (RBD) mutations (L452R, T478K, D614G), N-terminal domain (NTD) mutations (T17R, G142D, Δ156–157, A222V), and furin cleavage site (FCS) mutations (P681R, D950N). The functional consequences of common and unique variants among the first and second wave were evaluated by Sorting Intolerant from Tolerant (SIFT) and Protein Variant Effect Analyser (PROVEAN). Furthermore, we extensively investigated phylogenetic clustering of the genome sequences by Nextstrain and identified the contrasting divergence between first and second wave. Different sub division of delta clade (21I, 21 A, 21 J) and 21 B (kappa) with mutations primarily in spike proteins and nucleocapsid proteins, were exclusive to the second wave. Our study identified changes in spike proteins and nucleocapsid potentially contributing to increased transmission and infectivity during the second wave. Loci specific variant map for different countries across the world suggested the appearance of large number of variants associated with ORF1a during the second wave in India. Overall, the data underscores the dynamic nature of viral evolution during different phases of an outbreak, highlighting the importance of continuous genomic surveillance to track and understand viral mutations and their implications for public health interventions.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S2950194624000281Test; https://doaj.org/toc/2950-1946Test

الوصول الحر: https://doaj.org/article/0bf13a8bfb1c4f019e178c704105130fTest

المؤلفون: Pradeep Kumar G., Rajanikant Panda, Kanishka Sharma, A. Adarsh, Jitka Annen, Charlotte Martial, Marie-Elisabeth Faymonville, Steven Laureys, Corine Sombrun, Ramakrishnan Angarai Ganesan, Audrey Vanhaudenhuyse, Olivia Gosseries

المصدر: NeuroImage, Vol 293, Iss , Pp 120623- (2024)

مصطلحات موضوعية: High-order interaction, Synergy, Redundancy, O-information, Non-ordinary states of consciousness (NSCs), Rajyoga meditation, Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571

الوصف: High-order interactions are required across brain regions to accomplish specific cognitive functions. These functional interdependencies are reflected by synergistic information that can be obtained by combining the information from all the sources considered and redundant information (i.e., common information provided by all the sources). However, electroencephalogram (EEG) functional connectivity is limited to pairwise interactions thereby precluding the estimation of high-order interactions. In this multicentric study, we used measures of synergistic and redundant information to study in parallel the high-order interactions between five EEG electrodes during three non-ordinary states of consciousness (NSCs): Rajyoga meditation (RM), hypnosis, and auto-induced cognitive trance (AICT). We analyzed EEG data from 22 long-term Rajyoga meditators, nine volunteers undergoing hypnosis, and 21 practitioners of AICT. We here report the within-group changes in synergy and redundancy for each NSC in comparison with their respective baseline. During RM, synergy increased at the whole brain level in the delta and theta bands. Redundancy decreased in frontal, right central, and posterior electrodes in delta, and frontal, central, and posterior electrodes in beta1 and beta2 bands. During hypnosis, synergy decreased in mid-frontal, temporal, and mid-centro-parietal electrodes in the delta band. The decrease was also observed in the beta2 band in the left frontal and right parietal electrodes. During AICT, synergy decreased in delta and theta bands in left-frontal, right-frontocentral, and posterior electrodes. The decrease was also observed at the whole brain level in the alpha band. However, redundancy changes during hypnosis and AICT were not significant. The subjective reports of absorption and dissociation during hypnosis and AICT, as well as the mystical experience questionnaires during AICT, showed no correlation with the high-order measures. The proposed study is the first exploratory attempt to utilize the concepts of synergy and redundancy in NSCs. The differences in synergy and redundancy during different NSCs warrant further studies to relate the extracted measures with the phenomenology of the NSCs.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S1053811924001186Test; https://doaj.org/toc/1095-9572Test

الوصول الحر: https://doaj.org/article/863e3f3b43ad4d048fa4b0be4e5d924cTest

المؤلفون: Kris Sales, Paul Thomas, Matthew J. G. Gage, Ramakrishnan Vasudeva

المصدر: Royal Society Open Science, Vol 11, Iss 5 (2024)

مصطلحات موضوعية: climate change, sperm behaviour, thermal stress, spermatheca, Science

الوصف: Globally, heatwaves have become more common with hazardous consequences on biological processes. Research using a model insect (Tribolium castaneum) found that 5-day experimental heatwave conditions damaged several aspects of male reproductive biology, while females remained unaffected. However, females’ reproductive fitness may still be impacted, as insects typically store sperm from multiple males in specialized organs for prolonged periods. Consequently, using males which produce sperm with green fluorescent protein (GFP)-tagged sperm nuclei, we visualized in vivo whether thermal stress affects the ejaculate occupancy across female storage sites under two scenarios; (i) increasing time since insemination and (ii) in the presence of defending competitor sperm. We reconfirmed that sperm from heatwave-exposed males sired fewer offspring with previously mated females and provided new scenarios for in vivo distributions of heat-stress-exposed males’ sperm. Sperm from heatwave-exposed males occupied a smaller area and were at lower densities across the females’ storage sites. Generally, sperm occupancy decreased with time since insemination, and sperm from the first male to mate dominated the long-term storage site. Reassuringly, although heated males’ ejaculate was less successful in occupying female tracts, they were not lost from female storage at a faster rate and were no worse than control males in their offensive ability to enter storage sites occupied by competitor sperm. Future work should consider the potential site-specificity of factors influencing sperm storage where amenable.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2054-5703Test

الوصول الحر: https://doaj.org/article/39703b78c0db40029e89cfa40388f419Test

المؤلفون: Ramakrishnan, J.¹, Sankar, G. Ravi, Thavamani, K.

المصدر: 18(1):37-50