73 research outputs found

    Effect of dust and anthropogenic aerosols on columnar aerosol optical properties over Darjeeling (2200 m asl), Eastern Himalayas, India

    Get PDF
    Background: The loading of atmospheric particulate matter (aerosol) in the eastern Himalaya is mainly regulated by the locally generated anthropogenic aerosols from the biomass burning and by the aerosols transported from the distance sources. These different types of aerosol loading not only affect the aerosol chemistry but also produce consequent signature on the radiative properties of aerosol. Methodology/Principal Findings: An extensive study has been made to study the seasonal variations in aerosol components of fine and coarse mode aerosols and black carbon along with the simultaneous measurements of aerosol optical depth on clear sky days over Darjeeling, a high altitude station (2200 masl) at eastern Himalayas during the year 2008. We observed a heavy loading of fine mode dust component (Ca2+) during pre-monsoon (Apr - May) which was higher by 162 than its annual mean whereas during winter (Dec - Feb), the loading of anthropogenic aerosol components mainly from biomass burning (fine mode SO4 2- and black carbon) were higher (76 for black carbon and 96 for fine mode SO4 2-) from their annual means. These high increases in dust aerosols during pre-monsoon and anthropogenic aerosols during winter enhanced the aerosol optical depth by 25 and 40, respectively. We observed that for every 1 increase in anthropogenic aerosols, AOD increased by 0.55 during winter whereas for every 1 increase in dust aerosols, AOD increased by 0.46 during pre-monsoon. Conclusion/Significance: The natural dust transport process (during pre-monsoon) plays as important a role in the radiation effects as the anthropogenic biomass burning (during winter) and their differential effects (rate of increase of the AOD with that of the aerosol concentration) are also very similar. This should be taken into account in proper modeling of the atmospheric environment over eastern Himalayas

    The importance of the cellular stress response in the pathogenesis and treatment of type 2 diabetes

    Get PDF
    Organisms have evolved to survive rigorous environments and are not prepared to thrive in a world of caloric excess and sedentary behavior. A realization that physical exercise (or lack of it) plays a pivotal role in both the pathogenesis and therapy of type 2 diabetes mellitus (t2DM) has led to the provocative concept of therapeutic exercise mimetics. A decade ago, we attempted to simulate the beneficial effects of exercise by treating t2DM patients with 3 weeks of daily hyperthermia, induced by hot tub immersion. The short-term intervention had remarkable success, with a 1 % drop in HbA1, a trend toward weight loss, and improvement in diabetic neuropathic symptoms. An explanation for the beneficial effects of exercise and hyperthermia centers upon their ability to induce the cellular stress response (the heat shock response) and restore cellular homeostasis. Impaired stress response precedes major metabolic defects associated with t2DM and may be a near seminal event in the pathogenesis of the disease, tipping the balance from health into disease. Heat shock protein inducers share metabolic pathways associated with exercise with activation of AMPK, PGC1-a, and sirtuins. Diabetic therapies that induce the stress response, whether via heat, bioactive compounds, or genetic manipulation, improve or prevent all of the morbidities and comorbidities associated with the disease. The agents reduce insulin resistance, inflammatory cytokines, visceral adiposity, and body weight while increasing mitochondrial activity, normalizing membrane structure and lipid composition, and preserving organ function. Therapies restoring the stress response can re-tip the balance from disease into health and address the multifaceted defects associated with the disease

    Investigating a boronate-affinity-guided acylation reaction for labelling native antibodies

    No full text
    [[abstract]]The excellent molecular recognition capabilities of monoclonal antibodies (mAbs) have opened up exciting opportunities for biotherapeutic discovery. Taking advantage of the full potential of this tool necessitates affinity ligands capable of conjugating directly with small molecules to a defined degree of biorthogonality, especially when modifying natural Abs. Herein, a bioorthogonal boronate-affinity-based Ab ligand featuring a 4-(dimethylamino)pyridine and an S-aryl thioester to label full-length Abs is reported. The photoactivatable linker in the acyl donor facilitated purification of azide-labelled Ab (N3-Ab) was quantitatively cleaved upon brief exposure to UV light while retaining the original Ab activity. Click reactions enabled the precise addition of biotin, a fluorophore, and a pharmacological agent to the purified N3-Abs. The resulting immunoconjugate showed selectivity against targeted cells. Bioorthogonal traceless design and reagentless purification allow this strategy to be a powerful tool to engineer native antibodies amenable to therapeutic intervention

    Not Available

    No full text
    Not AvailableNot AvailableNot Availabl

    Not Available

    No full text
    Not AvailableNot AvailableNot Availabl
    corecore