Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
294
result(s) for
"Das, Prasenjit"
Sort by:
Perception towards online/blended learning at the time of Covid-19 pandemic: an academic analytics in the Indian context
by
Das, Prasenjit
,
Das, Kandarpa
,
Bordoloi, Ritimoni
in
Academic analytics
,
Behavioral Objectives
,
Blended Learning
2021
Purpose: During any crisis situation like a pandemic, war or natural disaster, online/blended learning could meet the academic needs of the learners in a bigger way. The use of information and communication technology (ICT)-based technologies has converted the entire teaching pedagogy to a learner centred pedagogy, following which the skills of using technology are to be seen as the most essential qualifications on the part of both the teachers/educators and learners. Therefore, the purpose of this paper is to understand the perceptions of the teachers and learners regarding the use of online/blended learning modes in teaching learning transactions. Another purpose of the paper being to find out the prospects and challenges of providing online/blended learning in a country like India, particularly during and in post-COVID-19 situations. Design/methodology/approach: The academic analytics approach was used for the study. A structured questionnaire was designed in Google Forms covering the perceptions of the teachers and learners in different Indian universities and colleges regarding online/blended services and analysis was done using Google Analytics. Further, analysis of the data received had been done by using simple statistical tool like percentage. Findings: Blended learning could be the solution for providing education in the context of the 21st century India. However, unlike in case of the conventional education, open education has widened the scope of learning adhering to the motto -- \"Bring your own device\" to learn. The extensive use of open educational resources, massive open online courses, social media and meeting apps during the COVID-19 lockdown, has opened up the minds of the knowledge-hungry people, further enabling them to receive the necessary educational inputs, training and skills even during the current pandemic situation. This is going to have a big impact in the ways of educational transactions in the days to come. Research limitations/implications: The discussions in the paper are limited to a study of representative states of India, and it is a general study only. The sample size was limited to only 120 as the response rate was significantly low compared to the number of addressees to whom the questionnaire was sent. Practical implications: This study will help in understanding the present state of online/blended learning in a country like India. The use of online learning was no doubt intensified by the sudden outbreak of the COVID-19 Pandemic. However, the study will also help in preparing a roadmap, at the policy level, regarding the beneficial use of online/blended teaching learning models both by the teachers and learners during any future crisis-like situations in a country like India. Social implications: Through this paper, a new social constructivism has been visualised to know the acceptability of online/blended learning opportunities on the part of the teachers and learners across India. If that social constructivism can actually be realised through the benefits of online learning, India might emerge as one of the important leaders of education in the coming days. To that extent, the COVID-19 pandemic can be seen as a blessing in disguise. Originality/value: It is important to examine the perceptions of both teachers and learners on the use of online learning in their regular curriculum transactions most particularly when the whole world is facing the brunt of the COVID-19 pandemic, which has adversely affected millions of learners across the world. The paper is original because it explores the current state of online/blended learning in a developing country like India to provide a practical and realistic vision of a new way of learning in the post-COVID-19 situations.
Journal Article
Mesenchymal tumors of the stomach: radiologic and pathologic correlation
2022
Mesenchymal tumors of the stomach are uncommon, with gastrointestinal stromal tumor (GIST) being the most common among them. Majority of the tumors may arise from cells of Cajal, smooth muscle cells, neural cells, totipotent stem cells, adipocytes or fibroblasts. Imaging plays an important role not only in staging but also in characterizing these tumors. Many of these tumors have characteristic imaging features. GISTs usually present as large cavitating and necrotic tumors with exophytic component. Presence of fat tissue within the tumor suggests a lipoma or a teratoma, early phase hyperenhancement indicates glomus tumor and hemangioma, and delayed contrast enhancement is seen in schwannoma. Their differentiation from epithelial tumors like carcinoma and neuroendocrine tumors is often possible based on the location (mesenchymal tumors are intramural), spread, morphological appearance and enhancement patterns. However, overlapping features exist between these tumors with imaging often being only suggestive. A biopsy is necessary for a definitive diagnosis in many cases.
Journal Article
ACE2 protein expression in lung tissues of severe COVID-19 infection
2022
Angiotensin-converting enzyme 2 (ACE2) is a key host protein by which severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) enters and multiplies within cells. The level of ACE2 expression in the lung is hypothesised to correlate with an increased risk of severe infection and complications in COrona VIrus Disease 2019 (COVID-19). To test this hypothesis, we compared the protein expression status of ACE2 by immunohistochemistry (IHC) in post-mortem lung samples of patients who died of severe COVID-19 and lung samples obtained from non-COVID-19 patients for other indications. IHC for CD61 and CD163 was performed for the assessment of platelet-rich microthrombi and macrophages, respectively. IHC for SARS-CoV-2 viral antigen was also performed. In a total of 55, 44 COVID-19 post-mortem lung samples were tested for ACE2, 36 for CD163, and 26 for CD61, compared to 15 non-covid 19 control lung sections. Quantification of immunostaining, random sampling, and correlation analysis were used to substantiate the morphologic findings. Our results show that ACE2 protein expression was significantly higher in COVID-19 post-mortem lung tissues than in controls, regardless of sample size. Histomorphology in COVID-19 lungs showed diffuse alveolar damage (DAD), acute bronchopneumonia, and acute lung injury with SARS-CoV-2 viral protein detected in a subset of cases. ACE2 expression levels were positively correlated with increased expression levels of CD61 and CD163. In conclusion, our results show significantly higher ACE2 protein expression in severe COVID-19 disease, correlating with increased macrophage infiltration and microthrombi, suggesting a pathobiological role in disease severity.
Journal Article
Panel of serum miRNAs as potential non-invasive biomarkers for pancreatic ductal adenocarcinoma
2021
Early-stage diagnosis of pancreatic ductal adenocarcinoma (PDAC) is difficult due to non-specific symptoms. Circulating miRNAs in body fluids have been emerging as potential non-invasive biomarkers for diagnosis of many cancers. Thus, this study aimed to assess a panel of miRNAs for their ability to differentiate PDAC from chronic pancreatitis (CP), a benign inflammatory condition of the pancreas. Next-generation sequencing was performed to identify miRNAs present in 60 FFPE tissue samples (27 PDAC, 23 CP and 10 normal pancreatic tissues). Four up-regulated miRNAs (miR-215-5p, miR-122-5p, miR-192-5p, and miR-181a-2-3p) and four down-regulated miRNAs (miR-30b-5p, miR-216b-5p, miR-320b, and miR-214-5p) in PDAC compared to CP were selected based on next-generation sequencing results. The levels of these 8 differentially expressed miRNAs were measured by qRT-PCR in 125 serum samples (50 PDAC, 50 CP, and 25 healthy controls (HC)). The results showed significant upregulation of miR-215-5p, miR-122-5p, and miR-192-5p in PDAC serum samples. In contrast, levels of miR-30b-5p and miR-320b were significantly lower in PDAC as compared to CP and HC. ROC analysis showed that these 5 miRNAs can distinguish PDAC from both CP and HC. Hence, this panel can serve as a non-invasive biomarker for the early detection of PDAC.
Journal Article
Mesenchymal stem cells offer a drug-tolerant and immune-privileged niche to Mycobacterium tuberculosis
2020
Anti-tuberculosis (TB) drugs, while being highly potent in vitro, require prolonged treatment to control
Mycobacterium tuberculosis
(
Mtb
) infections in vivo. We report here that mesenchymal stem cells (MSCs) shelter
Mtb
to help tolerate anti-TB drugs. MSCs readily take up
Mtb
and allow unabated mycobacterial growth despite having a functional innate pathway of phagosome maturation. Unlike macrophage-resident ones, MSC-resident
Mtb
tolerates anti-TB drugs remarkably well, a phenomenon requiring proteins ABCC1, ABCG2 and vacuolar-type H
+
ATPases. Additionally, the classic pro-inflammatory cytokines IFNγ and TNFα aid mycobacterial growth within MSCs. Mechanistically, evading drugs and inflammatory cytokines by MSC-resident
Mtb
is dependent on elevated PGE2 signaling, which we verify in vivo analyzing sorted CD45
−
Sca1
+
CD73
+
-MSCs from lungs of infected mice. Moreover, MSCs are observed in and around human tuberculosis granulomas, harboring
Mtb
bacilli. We therefore propose, targeting the unique immune-privileged niche, provided by MSCs to
Mtb
, can have a major impact on tuberculosis prevention and cure.
Treatment of tuberculosis needs to be taken for several weeks, despite good potency of drugs in vitro. Here, the authors show that mesenchymal stem cells can harbor
Mycobacterium tuberculosis
providing a niche for evasion of anti-bacterial drugs and cytokines.
Journal Article
Structure and Bonding in Planar Hypercoordinate Carbon Compounds
2022
The term hypercoordination refers to the extent of the coordination of an element by its normal value. In the hypercoordination sphere, the element can achieve planar and/or non-planar molecular shape. Hence, planar hypercoordinate carbon species violate two structural rules: (i) The highest coordination number of carbon is four and (ii) the tetrahedral orientation by the connected elements and/or groups. The unusual planar orientations are mostly stabilized by the electronic interactions of the central atom with the surrounding ligands. In this review article, we will talk about the current progress in the theoretical prediction of viable planar hypercoordinate carbon compounds. Primary knowledge of the planar hypercoordinate chemistry will lead to its forthcoming expansion. Experimental and theoretical interests in planar tetracoordinate carbon (ptC), planar pentacoordinate carbon (ppC), and planar hexacoordinate carbon (phC) are continued. The proposed electronic and mechanical strategies are helpful for the designing of the ptC compounds. Moreover, the 18-valence electron rule can guide the design of new ptC clusters computationally as well as experimentally. However, the counting of 18-valence electrons is not a requisite condition to contain a ptC in a cluster. Furthermore, this ptC idea is expanded to the probability of a greater coordination number of carbon in planar orientations. Unfortunately, until now, there are no such logical approaches to designing ppC, phC, or higher-coordinate carbon molecules/ions. There exist a few global minimum structures of phC clusters identified computationally, but none have been detected experimentally. All planar hypercoordinate carbon species in the global minima may be feasible in the gas phase.
Journal Article
Inflammatory signature in acute-on-chronic liver failure includes increased expression of granulocyte genes ELANE, MPO and CD177
by
Das, Prasenjit
,
Shalimar
,
Singh, Rohan
in
631/250
,
631/45
,
Acute-On-Chronic Liver Failure - metabolism
2021
Acute-on-Chronic Liver Failure (ACLF) is associated with innate immune dysfunction and high short-term mortality. Neutrophils have been identified to influence prognosis in ACLF. Neutrophil biology is under-evaluated in ACLF. Therefore, we investigated neutrophil-specific genes and their association with ACLF outcomes. This is an observational study. Enriched granulocytes, containing neutrophils, isolated from study participants in three groups- ACLF(n = 10), chronic liver disease (CLD, n = 4) and healthy controls (HC, n = 4), were analysed by microarray. Differentially expressed genes were identified and validated by qRT-PCR in an independent cohort of ACLF, CLD and HC (n = 30, 15 and 15 respectively). The association of confirmed overexpressed genes with ACLF 28-day non-survivors was investigated. The protein expression of selected neutrophil genes was confirmed using flow cytometry and IHC. Differential gene expression analysis showed 1140 downregulated and 928 upregulated genes for ACLF versus CLD and 2086 downregulated and 1091 upregulated genes for ACLF versus HC. Significant upregulation of neutrophilic inflammatory signatures were found in ACLF compared to CLD and HC. Neutrophil enriched genes
ELANE, MPO
and
CD177
were highly upregulated in ACLF and their expression was higher in ACLF 28-day non-survivors. Elevated expression of CD177 protein on neutrophil surface in ACLF was confirmed by flow cytometry. IHC analysis in archival post mortem liver biopsies showed the presence of CD177
+
neutrophils in the liver tissue of ACLF patients. Granulocyte genes
ELANE, MPO
and
CD177
are highly overexpressed in ACLF neutrophils as compared to CLD or HC. Further, this three-gene signature is highly overexpressed in ACLF 28-day non-survivors.
Journal Article
In Silico Studies on Selected Neutral Molecules, CGa2Ge2, CAlGaGe2, and CSiGa2Ge Containing Planar Tetracoordinate Carbon
by
Das, Prasenjit
,
Chattaraj, Pratim Kumar
in
ab initio molecular dynamics simulations
,
Aromaticity
,
Carbon
2021
Density functional theory (DFT) was used to study the structure, stability, and bonding in some selected neutral pentaatomic systems, viz., CGa2Ge2, CAlGaGe2, and CSiGa2Ge containing planar tetracoordinate carbon. The systems are kinetically stable, as predicted from the ab initio molecular dynamics simulations. The natural bond orbital (NBO) analysis showed that strong electron donation occurs to the central planar carbon atom by the peripheral atoms in all the studied systems. From the nucleus independent chemical shift (NICS) analysis, it is shown that the systems possess both σ- and π- aromaticity. The presence of 18 valence electrons in these systems, in their neutral form, appears to be important for their stability with planar geometries rather than tetrahedral structures. The nature of bonding is understood through the adaptive natural density partitioning analysis (AdNDP), quantum theory of atoms in molecules (QTAIM) analysis, and also via Wiberg bond index (WBI) and electron localization function (ELF).
Journal Article
An antibacterial compound pyrimidomycin produced by Streptomyces sp. PSAA01 isolated from soil of Eastern Himalayan foothill
by
Das, Prasenjit
,
Kundu, Shampa
,
Maiti, Pulak Kumar
in
631/326/22
,
631/326/22/1290
,
631/326/22/1434
2022
Selective isolation of soil Actinobacteria was undertaken to isolate a new class of antibiotics and bioactive molecules. A
Streptomyces
sp
.
PSAA01 (= MTCC 13,157), isolated from soil of Eastern Himalaya foothill was cultivated on a large scale for the production of the antimicrobial SM02. It has been found that the maximum amount of SM02 produced while PSAA01 was grown in ISP-2 medium (pH 7.0) for 7 days at 30 °C in shaking (180 rpm) condition. A significant zone of inhibition against
Staphylococcus aureus
MTCC 96 has been found with the crude cell-free culture media (50 µL) of 7 days grown PSAA01. After the purification and chemical structural characterization, we found that SM02 is a new antimicrobial having 746 dalton molecular weight. The compound SM02 contains pyrimidine moiety in it and is produced by a species of
Streptomyces
and thus we have named this antibiotic pyrimidomycin
.
The antimicrobial spectrum of pyrimidomycin has been found to be restricted in Gram-positive organisms with a MIC of 12 µg/mL. SM02 was found active against
Mycobacterium
sp. and also multi-drug resistant Gram-positive bacteria with similar potency and found to disrupt the bacterial cell wall. Pyrimidomycin also showed significant impairment in the biofilm formation by
S. aureus
. Furthermore, pyrimidomycin showed synergy with the most used antibiotic like ampicillin, vancomycin and chloramphenicol. Pyrimidomycin did not have cytotoxicity towards human cell lines indicating its limited activity within bacteria.
Journal Article