Publications by authors named "Narasimhan A"

Chronic obstructive pulmonary disease (COPD) is a primary chronic respiratory disease associated with pulmonary congestion that restricts airflow and thereby affects the exchange of gases between the alveoli and the blood capillaries in the lungs. Dual scale-global and local-porous medium models have been developed and reported in this work, to study the effects of air-side congestion on the blood-oxygen content in the alveolar region of the human lung. The human lung is model as a global, equivalent, heterogeneous porous medium comprising three zones with distinct permeabilities related to their progressively complex branching structure.

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Age-related macular degeneration (AMD) is a major cause of vision loss in older adults. AMD is caused by degeneration in the macula of the retina. The retina is the highest oxygen consuming tissue in our body and is prone to oxidative damage.

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Bacillus Calmette-Guerin (BCG) is the primary treatment for non-muscle-invasive bladder cancer (NMIBC), known to stimulate inflammatory cytokines, notably interferon (IFN)-γ. We observed that prolonged IFN-γ exposure fosters adaptive resistance in recurrent tumors, aiding immune evasion and tumor proliferation. We identify HLA-E and NKG2A, part of a novel NK and T cell checkpoint pathway, as key mediators of resistance in BCG-unresponsive NMIBC.

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Carinal resection of tumour involving trachea and carina remains as a challenge for thoracic surgeons and anaesthesiologists. Resection is technically demanding and can be associated with significant morbidity and mortality. In this case report, we describe the successful management of carinal tumour with carinal resection in a 45-year-old female.

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Introduction: Implementing perioperative interventions such as enhanced recovery pathways (ERPs) has improved short-term outcomes and minimized length of stay. Preliminary evidence suggests that adherence to the enhanced recovery after surgery protocol may also enhance 5-year cancer-specific survival (CSS) in colorectal cancer surgery. This retrospective study presents long-term survival outcomes and disease recurrence from a high-volume, single-center practice.

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COVID-19 has potential consequences on the pulmonary and cardiovascular health of millions of infected people worldwide. Chest computed tomographic (CT) imaging has remained the first line of diagnosis for individuals infected with SARS-CoV-2. However, differentiating COVID-19 from other types of pneumonia and predicting associated cardiovascular complications from the same chest-CT images have remained challenging.

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Article Synopsis
  • A study was conducted in India to investigate sudden unexplained deaths among healthy young adults (ages 18-45) possibly linked to COVID-19 infection or vaccination from October 2021 to March 2023.
  • The research analyzed data from 729 cases and 2,916 matching controls, assessing factors like COVID-19 vaccination status, family history, substance use, and physical activity.
  • Results indicated that receiving at least one COVID-19 vaccine dose reduced the likelihood of sudden death, while factors such as past hospitalization for COVID-19, family history of sudden deaths, binge drinking, and intense physical activity increased the risk.
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Brain research is an area of research characterized by its cutting-edge nature, with brain mapping constituting a crucial aspect of this field. As sequencing tools have played a crucial role in gene sequencing, brain mapping largely depends on automated, high-throughput and high-resolution imaging techniques. Over the years, the demand for high-throughput imaging has scaled exponentially with the rapid development of microscopic brain mapping.

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Organoids provide us an opportunity to understand how diseases affect cellular physiology, human tissues or organs. They are indespensible tools for biomaterial toxicity analysis, drug discovery and regenerative medicine.

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A successful attempt has been made to improve the mechanical properties of Hydroxyapatite (HAp) and reduced graphene oxide (rGO) composite nanoparticles (NPs). Various proportions of HAp and rGO were synthesized to improve the mechanical properties. HAp NPs were prepared using the wet precipitation method and further calcined to form crystalline particles.

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Sexual selection is a major force influencing the evolution of sexually reproducing species. Environmental factors such as larval density can manipulate adult condition and influence the direction and strength of sexual selection. While most studies on the influence of larval crowding on sexual selection are either correlational or single-generation manipulations, it is unclear how evolution under chronic larval crowding affects sexual selection.

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The development of rapid, noninvasive diagnostics to detect lung diseases is a great need after the COVID-2019 outbreak. The nanotechnology-based approach has improved imaging and facilitates the early diagnosis of inflammatory lung diseases. The multifunctional properties of nanoprobes enable better spatial-temporal resolution and a high signal-to-noise ratio in imaging.

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The targeted delivery of cancer immunotherapies has increased noticeably in recent years. Recent advancements in immunotherapy, particularly in blocking the immune checkpoints (ICs) axis, have shown favorable treatment outcomes for multiple types of cancer including melanoma and non-small-cell lung cancer (NSLC). Engineered micromachines, including microparticles, and nanoplatforms (organic and inorganic), functionalized with immune agonists can effectively deliver immune-targeting molecules to solid tumors.

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Purpose Of Review: Obesity has increased worldwide recently and represents a major global health challenge. This review focuses on the obesity-associated cellular senescence in various organs and the role of these senescent cells (SnCs) in driving complications associated with obesity. Also, the ability to target SnCs pharmacologically with drugs termed senotherapeutics as a therapy for these complications is discussed.

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Musculoskeletal diseases such as muscular dystrophy, cachexia, osteoarthritis, and rheumatoid arthritis impair overall physical health and reduce survival. Patients suffer from pain, dysfunction, and dysmobility due to inflammation and fibrosis in bones, muscles, and joints, both locally and systemically. The Interleukin-6 (IL-6) family of cytokines, most notably IL-6, is implicated in musculoskeletal disorders and cachexia.

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Male-biased operational sex ratios can increase male-male competition and can potentially select for both increased pre- and postcopulatory male success. In the present study, using populations of Drosophila melanogaster evolved under male-biased (M) or female-biased (F) sex ratios, we asked whether (a) male mating success can evolve, (b) males are better at mating females that they have coevolved with, (c) males mating success is affected by female mating status, and (d) male mating success is correlated with their courtship effort. We directly competed M and F males for mating with (a) virgin ancestral (common) females, (b) virgin females from the M and F populations, and (c) singly mated females from the M and F populations.

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Autism spectrum disorder (ASD) can be reliably diagnosed at 18 months, yet significant diagnostic delays persist in the United States. This double-blinded, multi-site, prospective, active comparator cohort study tested the accuracy of an artificial intelligence-based Software as a Medical Device designed to aid primary care healthcare providers (HCPs) in diagnosing ASD. The Device combines behavioral features from three distinct inputs (a caregiver questionnaire, analysis of two short home videos, and an HCP questionnaire) in a gradient boosted decision tree machine learning algorithm to produce either an ASD positive, ASD negative, or indeterminate output.

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Background: Cachexia is frequent, deadly, and untreatable for patients with pancreatic ductal adenocarcinoma (PDAC). The reproductive hormone and cytokine Activin is a mediator of PDAC cachexia, and Activin receptor targeting was clinically tested for cancer cachexia therapy. However, sex-specific manifestations and mechanisms are poorly understood, constraining development of effective treatments.

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Recently, considerable interest has emerged in the development of biosensors to detect biomarkers and immune checkpoints to identify and measure cancer through liquid biopsies. The detection of cancer biomarkers from a small volume of blood is relatively fast compared to the gold standard of tissue biopsies. Traditional immuno-histochemistry (IHC) requires tissue samples obtained using invasive procedures and specific expertise as well as sophisticated instruments.

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Tumor- and bone-derived soluble factors have been proposed to participate in the alterations of skeletal muscle size and function in cachexia. We previously showed that mice bearing ovarian cancer (OvCa) exhibit cachexia associated with marked bone loss, whereas bone-targeting agents, such as bisphosphonates, are able to preserve muscle mass in animals exposed to anticancer drugs. De-identified CT images and plasma samples from female patients affected with OvCa were used for body composition assessment and quantification of circulating cross-linked C-telopeptide type I (CTX-I) and receptor activator of NF-kB ligand (RANKL), respectively.

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An essential step toward understanding brain function is to establish a structural framework with cellular resolution on which multi-scale datasets spanning molecules, cells, circuits and systems can be integrated and interpreted. Here, as part of the collaborative Brain Initiative Cell Census Network (BICCN), we derive a comprehensive cell type-based anatomical description of one exemplar brain structure, the mouse primary motor cortex, upper limb area (MOp-ul). Using genetic and viral labelling, barcoded anatomy resolved by sequencing, single-neuron reconstruction, whole-brain imaging and cloud-based neuroinformatics tools, we delineated the MOp-ul in 3D and refined its sublaminar organization.

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Diverse types of glutamatergic pyramidal neurons mediate the myriad processing streams and output channels of the cerebral cortex, yet all derive from neural progenitors of the embryonic dorsal telencephalon. Here we establish genetic strategies and tools for dissecting and fate-mapping subpopulations of pyramidal neurons on the basis of their developmental and molecular programs. We leverage key transcription factors and effector genes to systematically target temporal patterning programs in progenitors and differentiation programs in postmitotic neurons.

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