Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (8)

Search Parameters:
Authors = Ambika Sharma

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
17 pages, 6736 KiB  
Article
The Role of Sirtuin-1 Isoforms in Regulating Mitochondrial Function
by Pankaj Patyal, Fathima S. Ameer, Ambika Verma, Xiaomin Zhang, Gohar Azhar, Jyotsna Shrivastava, Shakshi Sharma, Rachel Zhang and Jeanne Y. Wei
Curr. Issues Mol. Biol. 2024, 46(8), 8835-8851; https://doi.org/10.3390/cimb46080522 - 14 Aug 2024
Cited by 5 | Viewed by 2055
Abstract
The sirtuin-1 (SIRT1) gene contains multiple exons that usually undergo alternative splicing. The exclusion of one or more exons causes domain loss in the alternatively spliced isoforms and may change their functions. However, it is not completely established to what extent the loss [...] Read more.
The sirtuin-1 (SIRT1) gene contains multiple exons that usually undergo alternative splicing. The exclusion of one or more exons causes domain loss in the alternatively spliced isoforms and may change their functions. However, it is not completely established to what extent the loss of a non-catalytic domain could affect its regulatory function. Using muscle cells and SIRT1-knockout cells, we examined the function of the constitutively spliced isoform (SIRT1-v1) versus the alternatively spliced isoforms SIRT1-v2 and SIRT1-v3 that had lost part of the N-terminal region. Our data indicate that partial loss of the N-terminal domains in SIRT1-v2 and SIRT1-v3 attenuated their function. The full-length SIRT1-v1 significantly increased the oxidative phosphorylation and ATP production rate. Furthermore, SIRT1-v1 specifically upregulated the mitochondrial respiratory complex I without affecting the activity of complexes II, III, and IV. Additionally, domain loss affected the regulation of site-specific lysine acetylation in the histone H4 protein, the gene expression of respiratory complex I subunits, and the metabolic balance of oxidative phosphorylation versus glycolysis. Since alternatively spliced isoforms tend to increase with advancing age, the impact of SIRT1 isoforms on mitochondrial respiratory complexes warrants further investigation. Full article
(This article belongs to the Section Biochemistry, Molecular and Cellular Biology)
Show Figures

Figure 1

13 pages, 703 KiB  
Article
Chemical Composition, Market Survey, and Safety Assessment of Blue Lotus (Nymphaea caerulea Savigny) Extracts
by Noura S. Dosoky, Sara A. Shah, Joseph T. Dawson, Sushant Sharma Banjara, Ambika Poudel, Cécile Bascoul and Prabodh Satyal
Molecules 2023, 28(20), 7014; https://doi.org/10.3390/molecules28207014 - 10 Oct 2023
Cited by 6 | Viewed by 9637
Abstract
Blue lotus, also known as Nymphaea caerulea (Nymphaeaceae), is a water lily found globally in lakes and rivers. With its long history of use in Egyptian culture, blue lotus has been associated with spiritual rituals and health benefits. Nowadays, blue lotus is still [...] Read more.
Blue lotus, also known as Nymphaea caerulea (Nymphaeaceae), is a water lily found globally in lakes and rivers. With its long history of use in Egyptian culture, blue lotus has been associated with spiritual rituals and health benefits. Nowadays, blue lotus is still consumed as a tea or tincture to induce relaxation and heightened spiritual awareness. In this study, six authentic N. caerulea extracts from trusted sources and eleven commercial products were analyzed using gas chromatography−mass spectrometry (GC-MS). Authentic blue lotus extracts were produced in industrial settings. Overall, the extracts were a mixture of aliphatic hydrocarbons, aromatic alcohols, fatty acids, phenyl derivatives, diterpenoids, phytosterols, and stigmastanes. Apomorphine and nuciferine, which are responsible for psychoactive effects of the blue lotus flower, were virtually absent from the authentic blue lotus extract. Although blue lotus has a long history of use, the safety data on the plant and its extracts is limited; however, together with the analytical data, the available information does not indicate major safety concerns for the topical application of authentic blue lotus flower concrete or absolute when diluted as a fragrance ingredient. Full article
(This article belongs to the Special Issue Study on Extraction and Chemical Constituents of Natural Extracts)
Show Figures

Graphical abstract

10 pages, 1947 KiB  
Case Report
Metagenomic Analysis of the Outdoor Dust Microbiomes: A Case Study from Abu Dhabi, UAE
by Lina Maloukh, Yousef Nazzal, Alagappan Kumarappan, Fares Howari, Lakshmi Kesari Ambika, Rihab Yahmadi, Manish Sharma, Jibran Iqbal, Ahmed A. Al-Taani, Imen Ben Salem, Cijo M. Xavier and Muhamad Naseem
Atmosphere 2023, 14(2), 327; https://doi.org/10.3390/atmos14020327 - 7 Feb 2023
Cited by 4 | Viewed by 3300
Abstract
Outdoor dust covers a shattered range of microbial agents from land over transportation, human microbial flora, which includes pathogen and commensals, and airborne from the environment. Dust aerosols are rich in bacterial communities that have a major impact on human health and living [...] Read more.
Outdoor dust covers a shattered range of microbial agents from land over transportation, human microbial flora, which includes pathogen and commensals, and airborne from the environment. Dust aerosols are rich in bacterial communities that have a major impact on human health and living environments. In this study, outdoor samples from roadside barricades, safety walls, and fences (18 samples) were collected from Abu Dhabi, UAE and bacterial diversity was assessed through a 16S rRNA amplicon next generation sequencing approach. Clean data from HiSeq produced 1,099,892 total reads pairs for 18 samples. For all samples, taxonomic classifications were assigned to the OTUs (operational taxonomic units) representative sequence using the Ribosomal Database Project database. Analysis such as alpha diversity, beta diversity, differential species analysis, and species relative abundance were performed in the clustering of samples and a functional profile heat map was obtained from the OTUs by using bioinformatics tools. A total of 2814 OTUs were identified from those samples with a coverage of more than 99%. In the phylum, all 18 samples had most of the bacterial groups such as Actinobacteria, Proteobacteria, Firmicutes, and Bacteroidetes. Twelve samples had Propionibacteria acnes and were mainly found in RD16 and RD3. Major bacteria species such as Propionibacteria acnes, Bacillus persicus, and Staphylococcus captis were found in all samples. Most of the samples had Streptococcus mitis, Staphylococcus capitis. and Nafulsella turpanensis and Enhydrobacter aerosaccus was part of the normal microbes of the skin. Salinimicrobium sp., Bacillus alkalisediminis, and Bacillus persicus are halophilic bacteria found in sediments. The heat map clustered the samples and species in vertical and horizontal classification, which represents the relationship between the samples and bacterial diversity. The heat map for the functional profile had high properties of amino acids, carbohydrate, and cofactor and vitamin metabolisms of all bacterial species from all samples. Taken together, our analyses are very relevant from the perspective of out-door air quality, airborne diseases, and epidemics, with broader implications for health safety and monitoring. Full article
(This article belongs to the Special Issue Outdoor Air Pollution and Human Health (2nd Edition))
Show Figures

Figure 1

14 pages, 3250 KiB  
Article
P. gingivalis-LPS Induces Mitochondrial Dysfunction Mediated by Neuroinflammation through Oxidative Stress
by Ambika Verma, Gohar Azhar, Xiaomin Zhang, Pankaj Patyal, Grishma Kc, Shakshi Sharma, Yingni Che and Jeanne Y. Wei
Int. J. Mol. Sci. 2023, 24(2), 950; https://doi.org/10.3390/ijms24020950 - 4 Jan 2023
Cited by 27 | Viewed by 5074
Abstract
Porphyromonas gingivalis (P. gingivalis), a key pathogen in periodontitis, is associated with neuroinflammation. Periodontal disease increases with age; 70.1% of adults 65 years and older have periodontal problems. However, the P. gingivalis- lipopolysaccharide (LPS)induced mitochondrial dysfunction in neurodegenerative diseases remains elusive. In [...] Read more.
Porphyromonas gingivalis (P. gingivalis), a key pathogen in periodontitis, is associated with neuroinflammation. Periodontal disease increases with age; 70.1% of adults 65 years and older have periodontal problems. However, the P. gingivalis- lipopolysaccharide (LPS)induced mitochondrial dysfunction in neurodegenerative diseases remains elusive. In this study, we investigated the possible role of P. gingivalis-LPS in mitochondrial dysfunction during neurodegeneration. We found that P. gingivalis-LPS treatment activated toll-like receptor (TLR) 4 signaling and upregulated the expression of Alzheimer’s disease-related dementia and neuroinflammatory markers. Furthermore, the LPS treatment significantly exacerbated the production of reactive oxygen species and reduced the mitochondrial membrane potential. Our study highlighted the pivotal role of P. gingivalis-LPS in the repression of serum response factor (SRF) and its co-factor p49/STRAP that regulate the actin cytoskeleton. The LPS treatment repressed the genes involved in mitochondrial function and biogenesis. P. gingivalis-LPS negatively altered oxidative phosphorylation and glycolysis and reduced total adenosine triphosphate (ATP) production. Additionally, it specifically altered the mitochondrial functions in complexes I, II, and IV of the mitochondrial electron transport chain. Thus, it is conceivable that P. gingivalis-LPS causes mitochondrial dysfunction through oxidative stress and inflammatory events in neurodegenerative diseases. Full article
(This article belongs to the Special Issue Mitochondria in Human Health and Disease)
Show Figures

Graphical abstract

16 pages, 3877 KiB  
Article
Simultaneous Removal of Organic Matter and Nutrients from High Strength Organic Wastewater Using Sequencing Batch Reactor (SBR)
by Ambika Sharma and Manpreet Singh Bhatti
Processes 2022, 10(10), 1903; https://doi.org/10.3390/pr10101903 - 20 Sep 2022
Cited by 8 | Viewed by 4485
Abstract
Industrial wastewater discharges often contain high levels of organic matter and nutrients, which can lead to eutrophication and constitute a serious hazard to receiving waters and aquatic life. The purpose of this study was to examine the efficacy of using a sequencing batch [...] Read more.
Industrial wastewater discharges often contain high levels of organic matter and nutrients, which can lead to eutrophication and constitute a serious hazard to receiving waters and aquatic life. The purpose of this study was to examine the efficacy of using a sequencing batch reactor (SBR) to treat high-strength organic wastewater for the removal of both chemical oxygen demand (COD) and nutrients (nitrogen and phosphorus). At a constant COD concentration of approximately 1000 mg/L, the effects of cycle time (3 and 9 h) and various C:N:P ratios (100:5:2, 100:5:1, 100:10:1, and 100:10:2) were investigated using four identical SBRs (R1, R2, R3, and R4). According to experimental data, a significant high removal, i.e., 90%, 98.5%, and 84.8%, was observed for COD, NH3-N, and PO43−-P, respectively, when C:N:P was 100:5:1, at a cycle time of 3 h. Additionally, when cycle time was increased to 9 h, the highest levels of COD removal (95.7%), NH3-N removal (99.6%), and PO43−-P removal (90.31%) were accomplished. Also, in order to comprehend the primary impacts and interactions among the various process variables, the data was statistically examined using analysis of variance (ANOVA) at a 95% confidence level, which revealed that the interaction of cycle time and C/N ratio, cycle time and C/P ratio is significant for COD and NH3-N removal. However, the same interaction was found to be insignificant for PO43−-P removal. Sludge volume index (SVI30 and SVI10) and sludge settleability were studied, and the best settling was found in R3 with SVI30 of 55 mL/g after 9 h. Further evidence that flocs were present in reactors came from an average ratio of SVI 30/SVI 10 = 0.70 after 9 h and 0.60 after 3 h. Full article
(This article belongs to the Special Issue Biological and Chemical Wastewater Treatment Processes)
Show Figures

Figure 1

21 pages, 2842 KiB  
Article
Privacy Preservation in Online Social Networks Using Multiple-Graph-Properties-Based Clustering to Ensure k-Anonymity, l-Diversity, and t-Closeness
by Rupali Gangarde, Amit Sharma, Ambika Pawar, Rahul Joshi and Sudhanshu Gonge
Electronics 2021, 10(22), 2877; https://doi.org/10.3390/electronics10222877 - 22 Nov 2021
Cited by 27 | Viewed by 4163
Abstract
As per recent progress, online social network (OSN) users have grown tremendously worldwide, especially in the wake of the COVID-19 pandemic. Today, OSNs have become a core part of many people’s daily lifestyles. Therefore, increasing dependency on OSNs encourages privacy requirements to protect [...] Read more.
As per recent progress, online social network (OSN) users have grown tremendously worldwide, especially in the wake of the COVID-19 pandemic. Today, OSNs have become a core part of many people’s daily lifestyles. Therefore, increasing dependency on OSNs encourages privacy requirements to protect users from malicious sources. OSNs contain sensitive information about each end user that intruders may try to leak for commercial or non-commercial purposes. Therefore, ensuring different levels of privacy is a vital requirement for OSNs. Various privacy preservation methods have been introduced recently at the user and network levels, but ensuring k-anonymity and higher privacy model requirements such as l-diversity and t-closeness in OSNs is still a research challenge. This study proposes a novel method that effectively anonymizes OSNs using multiple-graph-properties-based clustering. The clustering method introduces the goal of achieving privacy of edge, node, and user attributes in the OSN graph. This clustering approach proposes to ensure k-anonymity, l-diversity, and t-closeness in each cluster of the proposed model. We first design the data normalization algorithm to preprocess and enhance the quality of raw OSN data. Then, we divide the OSN data into different clusters using multiple graph properties to satisfy the k-anonymization. Furthermore, the clusters ensure improved k-anonymization by a novel one-pass anonymization algorithm to address l-diversity and t-closeness privacy requirements. We evaluate the performance of the proposed method with state-of-the-art methods using a “Yelp real-world dataset”. The proposed method ensures high-level privacy preservation compared to state-of-the-art methods using privacy metrics such as anonymization degree, information loss, and execution time. Full article
Show Figures

Figure 1

16 pages, 3605 KiB  
Review
From Challenges to Creativity: Enhancing SMEs’ Resilience in the Context of COVID-19
by Ambika Zutshi, John Mendy, Gagan Deep Sharma, Asha Thomas and Tapan Sarker
Sustainability 2021, 13(12), 6542; https://doi.org/10.3390/su13126542 - 8 Jun 2021
Cited by 142 | Viewed by 26044
Abstract
COVID-19 pandemic has brought significant and multiple challenges for SMEs. While SMEs have traditionally faced financial and non-financial crises, the pandemic has brought about additional uncertainties on how to maintain business continuity. The purpose of this paper is to examine how SMEs can [...] Read more.
COVID-19 pandemic has brought significant and multiple challenges for SMEs. While SMEs have traditionally faced financial and non-financial crises, the pandemic has brought about additional uncertainties on how to maintain business continuity. The purpose of this paper is to examine how SMEs can mitigate against COVID-19-related crisis by examining the impacts that the pandemic has had on them through a review of 34 articles. The thematic analysis from the literature covered three overarching and inter-related challenges including (i) cost and finance-related challenges, (ii) disruption of activities, and (iii) existential difficulties. The paper’s value lies in addressing the gap between the espoused literature’s claim of the beneficial impact of new technological advancements and SMEs’ ability to survive in the context of the COVID-19 pandemic. The additional value of this paper is a framework of recommendations to help enhance SMEs’ resilience and responsiveness in the context of COVID-19. These recommendations include collaboration, openness, taking advantage of opportunities/victory, and durability. Full article
Show Figures

Figure 1

16 pages, 2610 KiB  
Review
Role of Structural and Non-Structural Proteins and Therapeutic Targets of SARS-CoV-2 for COVID-19
by Rohitash Yadav, Jitendra Kumar Chaudhary, Neeraj Jain, Pankaj Kumar Chaudhary, Supriya Khanra, Puneet Dhamija, Ambika Sharma, Ashish Kumar and Shailendra Handu
Cells 2021, 10(4), 821; https://doi.org/10.3390/cells10040821 - 6 Apr 2021
Cited by 364 | Viewed by 30697
Abstract
Coronavirus belongs to the family of Coronaviridae, comprising single-stranded, positive-sense RNA genome (+ ssRNA) of around 26 to 32 kilobases, and has been known to cause infection to a myriad of mammalian hosts, such as humans, cats, bats, civets, dogs, and camels with [...] Read more.
Coronavirus belongs to the family of Coronaviridae, comprising single-stranded, positive-sense RNA genome (+ ssRNA) of around 26 to 32 kilobases, and has been known to cause infection to a myriad of mammalian hosts, such as humans, cats, bats, civets, dogs, and camels with varied consequences in terms of death and debilitation. Strikingly, novel coronavirus (2019-nCoV), later renamed as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), and found to be the causative agent of coronavirus disease-19 (COVID-19), shows 88% of sequence identity with bat-SL-CoVZC45 and bat-SL-CoVZXC21, 79% with SARS-CoV and 50% with MERS-CoV, respectively. Despite key amino acid residual variability, there is an incredible structural similarity between the receptor binding domain (RBD) of spike protein (S) of SARS-CoV-2 and SARS-CoV. During infection, spike protein of SARS-CoV-2 compared to SARS-CoV displays 10–20 times greater affinity for its cognate host cell receptor, angiotensin-converting enzyme 2 (ACE2), leading proteolytic cleavage of S protein by transmembrane protease serine 2 (TMPRSS2). Following cellular entry, the ORF-1a and ORF-1ab, located downstream to 5′ end of + ssRNA genome, undergo translation, thereby forming two large polyproteins, pp1a and pp1ab. These polyproteins, following protease-induced cleavage and molecular assembly, form functional viral RNA polymerase, also referred to as replicase. Thereafter, uninterrupted orchestrated replication-transcription molecular events lead to the synthesis of multiple nested sets of subgenomic mRNAs (sgRNAs), which are finally translated to several structural and accessory proteins participating in structure formation and various molecular functions of virus, respectively. These multiple structural proteins assemble and encapsulate genomic RNA (gRNA), resulting in numerous viral progenies, which eventually exit the host cell, and spread infection to rest of the body. In this review, we primarily focus on genomic organization, structural and non-structural protein components, and potential prospective molecular targets for development of therapeutic drugs, convalescent plasm therapy, and a myriad of potential vaccines to tackle SARS-CoV-2 infection. Full article
Show Figures

Figure 1

Back to TopTop