Investigation and mitigation of degradation of fuel cells

<p>2016 First Place and People's Choice winner</p> <p>Department of Mechanical Engineering</p

Investigation and Mitigation of Degradation in Hydrogen Fuel Cells

<p>The ever increasing demand of petroleum in the transport sector has led to depletion of low cost/low risk reserves, increased levels of pollution, and greenhouse gas emissions that take a heavy toll on the environment as well as the national economy. There is an urgent need to use alternative energy resources along with an efficient and affordable energy conversion system to arrest environmental degradation. Polymer electrolyte fuel cells (PEFCs) show great promise in this regard - they use hydrogen gas as a fuel that electrochemically reacts with air to produce electrical energy and water as the by product. In a fuel cell electric vehicle (FCEV), these zero tail pipe emission systems offer high efficiency and power density for medium-heavy duty and long range transportation. However, PEFC technology is currently challenged by its limited durability when subjected to harsh and adverse operating conditions and transients that arises during the normal course of vehicle operation. The hydrogen-based fuel cell power train for electric vehicles must achieve high durability while maintaining high power efficiency and fuel economy in order to equal the range and lifetime of an internal-combustion-engine vehicle. The technology also needs to meet the cost targets to make FCEVs a commercial success. In this dissertation, one of the degradation phenomena that severely impede the durability of the system has been investigated. In scenarios where the cell becomes locally starved of hydrogen fuel, “cell reversal” occurs, which causes the cell to consume itself through carbon corrosion and eventually fail. Carbon corrosion in the anode disrupts the original structure of the electrode and can cause undesirable outcomes like catalyst particle migration, aggregation, loss of structural and chemical integrity. A comprehensive study using advanced electrochemical diagnostics and high resolution 3D imaging was performed and a new understanding to extend PEFC life time and robustness, by implementing engineered materials solutions, has been achieved. This will eventually help in making fuel cell systems more efficient, durable and economically viable, in order to better harness clean energy resources.</p

CHIKUNGUNYA, SCRUB TYPHUS MONO, AND CO-INFECTION AMONG PATIENTS WITH UNDIFFERENTIATED FEBRILE ILLNESS: A HOSPITAL-BASED STUDY

Objectives: Chikungunya virus is a common arthropod-related acute febrile disease and it is transmitted by Aedes aegypti or Aedes albopictus species. On the other hand, the bacterium Orientia tsutsugamushi causes scrub typhus, which is also an acute febrile illness with multiple organ involvement. Coinfection of chikungunya and scrub typhus may lead to severe manifestation including severe respiratory and central nervous system (CNS) complications. Coinfection of chikungunya and scrub typhus may lead to severe manifestation including severe respiratory and CNS complications. Therefore, the proper diagnosis can prevent the clinical complications. The aim and objective of our study is to find the seroprevalence of chikungunya and scrub typhus and coinfection of both through medical assessment and serological research of these patients presented with acute febrile infection at Diamond Harbour Government Medical College and Hospital. Methods: A prospective study was conducted from August 2022 to January 2023 at VRDL, Department of Microbiology, Diamond Harbour Government Medical College and Hospital. Serum was collected for IgM antibody enzyme-linked immunosorbent assay (ELISA) for scrub typhus (In bios kit) and Chikungunya (NIV Chikungunya IgM Capture ELISA Kit) test. Four hundred and eighty-seven samples were tested for IgM antibody by chikungunya and scrub typhus ELISA kit. Result: The present study demonstrated that, from the month of August 2022 to January 2023, 67% of chikungunya cases, 25% cases with only scrub typhus, and 8% cases with both chikungunya and scrub typhus presented positive. A present study shows that chikungunya is slightly more prevalent in males as compared to females, where scrub typhus is equally positive in both male and female patients. Conclusion: Laboratory testing of both of the diseases can prevent the complication of other suspected disease in coinfected patients

A novel role of tumor suppressor ZMYND8 in inducing differentiation of breast cancer cells through its dual-histone binding function

Accumulating evidences indicate the involvement of epigenetic deregulations in cancer. While some epigenetic regulators with aberrant functions in cancer are targeted for improving therapeutic outcome in patients, reinstating the functions of tumor-suppressor-like epigenetic regulators might further potentiate anti-cancer therapies. Epigenetic reader zinc-finger MYND-type-containing 8 (ZMYND8) has been found to be endowed with multiple anti-cancer functions like inhibition of tumor cell migration and proliferation. Here, we report another novel tumor suppressor role of ZMYND8 as an inducer of differentiation in breast cancer cells, by upregulating differentiation genes. Interestingly, we also demonstrated that ZMYND8 mediates all its antitumor roles through a common dual-histone mark binding to H4K16Ac and H3K36Me2. We validated these findings by both biochemical and biophysical analyses. Furthermore, we also confirmed the differentiationinducing potential of ZMYND8 in vivo, using 4T1 murine breast cancer model in Balb/c mice. Differentiation therapy holds great promise in cancer therapy, since it is non-toxic and makes the cancer cells therapysensitive. In this scenario, we propose epigenetic reader ZMYND8 as a potential therapeutic candidate for differentiation therapy in breast cancer

Suppression of poised oncogenes by ZMYND8 promotes chemo-sensitization

The major challenge in chemotherapy lies in the gain of therapeutic resistance properties of cancer cells. The relatively small fraction of chemo-resistant cancer cells outgrows and are responsible for tumor relapse, with acquired invasiveness and stemness. We demonstrate that zinc-finger MYND type-8 (ZMYND8), a putative chromatin reader, suppresses stemness, drug resistance, and tumor-promoting genes, which are hallmarks of cancer. Reinstating ZMYND8 suppresses chemotherapeutic drug doxorubicin-induced tumorigenic potential (at a sublethal dose) and drug resistance, thereby resetting the transcriptional program of cells to the epithelial state. The ability of ZMYND8 to chemo-sensitize doxorubicin-treated metastatic breast cancer cells by downregulating tumor-associated genes was further confirmed by transcriptome analysis. Interestingly, we observed that ZMYND8 overexpression in doxorubicin-treated cells stimulated those involved in a good prognosis in breast cancer. Consistently, sensitizing the cancer cells with ZMYND8 followed by doxorubicin treatment led to tumor regression in vivo and revert back the phenotypes associated with drug resistance and stemness. Intriguingly, ZMYND8 modulates the bivalent or poised oncogenes through its association with KDM5C and EZH2, thereby chemo-sensitizing the cells to chemotherapy for better disease-free survival. Collectively, our findings indicate that poised chromatin is instrumental for the acquisition of chemo-resistance by cancer cells and propose ZMYND8 as a suitable epigenetic tool that can re-sensitize the chemo-refractory breast carcinoma