Improved Thermoelectric Properties in (1-x)LaCoO3/(x)La0.7Sr0.3CoO3 Composite

A high Seebeck coefficient (S), large electrical conductivity ({\sigma}), and reduced thermal conductivity ({\kappa}) are required to achieve a high figure-of-merit (zT) in an ideal thermoelectric (TE) system, which is challenging in a single system due to the interdependence of TE parameters. Composite approach is promising to manipulate the TE parameters. In this study, TE properties of (1-x)LaCoO3/(x)La0.7Sr0.3CoO3 (0.00 \leq x \leq 0.05) composite is discussed. The structural analysis confirms individual phases in the composite, which is further supported by electron microscopy analysis. The x-ray photoelectron analysis indicates that oxygen vacancies (VO) are present in the parent LaCoO3 system and increase with the addition of La0.7Sr0.3CoO3 (LSCO) in the composite. The increase in VO raises the degenerate states of cobalt and hence improves S in the composites. Temperature variation in S and {\sigma} are consistent with the spin-state transition and shows the correlation between these two parameters. The reduction in {\kappa} and {\sigma} with the addition of ball-milled La0.7Sr0.3CoO3 in the composite is attributed to the enhanced phonon-phonon and charge carrier scattering, respectively. A synergistic effect of enhanced S and reduced \kappa} result in five times improvement in zT of the composite compared to the parent LaCoO3 system at 800 K. This approach also improves the operating temperature for LaCoO3 based systems.Comment: 26 pages, 10 figures, 4 table

Colossal Seebeck coefficient in Aurivillius Phase-Perovskite Oxide Composite

We propose an inexpensive scalable approach for achieving extremely high values of Seebeck coefficient ($\alpha$) by exploiting the natural superlattice structure in Aurivillius phase oxides. In particular, we report an $\alpha \approx$ 319\,mV/K at 300\,K in a composite of Aurivillius phase compound SrBi$_4$Ti$_4$O$_{15}$ (as a matrix) and a perovskite phase material (e.g., La$_{0.7}$Sr$_{0.3}$MnO$_3$ or, La$_{0.7}$Sr$_{0.3}$CoO$_3$ as filler). Such a colossal value of $\alpha$ can be attributed to contributions from the enhanced density of states due to the effective low dimensional character of Bi$_2$O$_2$ layer. The corresponding thermal conductivity ($\kappa$) and the electrical conductivity ($\sigma$) lies in the range 0.7 - 1.25 W/m-K and 10 - 100 $\mu$S/m, respectively at 300\,K. Attributed to the high $\alpha$ values, such oxide composites can be used as thermopile sensors and highly sensitive bolometric applications. We anticipate that the demonstration of colossal $\alpha$ in oxide composites using a simple synthesis strategy also sets the stage for future material innovations for high temperature thermoelectric applications.Comment: 5 figures, 1 tabl

Thermoelectric Properties of (1-x)LaCoO3.x_{3.x}La0.7_{0.7}Sr0.3_{0.3}MnO3_3 Composite

We report the thermoelectric (TE) properties of (1-x)LaCoO3.xLa0.7Sr0.3MnO3 (0 < x < 0.10) composite in a temperature range 320-800 K. Addition of La0.7Sr0.3MnO3 to LaCoO3 in small amount (5 weight %) improves the overall Seebeck coefficient ({\alpha}) at higher temperatures. The electrical conductivity, however, decreases due to a decrease in carrier concentration of the composite. The decrease in electrical conductivity of the composite at high temperature may be attributed to the insulating nature of the LSMO above room temperature. Thermal conductivity (\k{appa}) of all the samples increases with an increase in the temperature but decreases with increasing LSMO content. We also report the local variation of the Seebeck coefficient across the composite samples measured using a precision Seebeck measurement system. A maximum value of 0.09 for the figure of merit (ZT) is obtained for 0.95LaCoO3.0.05La0.7Sr0.3MnO3 at 620 K which is significantly higher than the ZT of either of LaCoO3 or La0.7Sr0.3MnO3 at 620 K. This suggests the potential for enhancement of operating temperatures of hitherto well known low-temperature thermoelectric materials through suitable compositing approach.Comment: 16 pages, 7 figures, 2 tables. arXiv admin note: text overlap with arXiv:1807.0556

Acute dislocation of fully deployed stent after use of non-compliant balloon: an enigma

Stent embolism is an established but rare complication of percutaneous coronary intervention, usually encountered when an undeployed stent unintentionally dislocates from the balloon. Published literature regarding incidence or clinical outcomes of embolism of fully deployed coronary stents is sparse. Here we report an unusual case of a 41-year-old male who had dislocation of a fully deployed stent into the distal part of left anterior descending artery following post dilatation by non-compliant balloon during percutaneous coronary intervention

Joga i rehabilitacja kardiologiczna (Yoga-CaRe) u osób po przebyciu ostrego epizodu wieńcowego

Cardiovascular diseases are a leading cause of death and disability in Asian Indians with huge psychological and economic impact as it affects population in thirty- and forty-year-olds, previously healthy adults and most productive social group. Successful transcatheter therapeutics has opened a new vista for its management; however, it cannot prevent its recurrence. Therefore, secondary prevention is cornerstone of management. Yoga-based Cardiac Rehabilitation (Yoga-CaRe) is a multifaceted approach targeting patient’s physical, psychological, social and occupational status, preventing or delaying the progression of underlying disease and reducing the risk of recurrent rehospitalization and death as well as enabling the patients to live a comfortable and active life. Yoga is an ancient Indian system of philosophy; a mind-body discipline encompassing an array of philosophical precepts, mental attitudes and physical practice. Of seven major branches of yoga, Hatha yoga, which itself includes many different styles (e.g. Iyenger, Ashtanga, etc.), is probably the most commonly recognized, and incorporates elements of physical poses, breath control and meditation, and self-restraint (including that of diet, smoking, alcohol intake and sleep patterns). A Cochrane review reported a 27% reduction in total mortality and 19% reduction in total mortality and non-fatal cardiac events with cardiac rehabilitation (CR), comparing favorably to effective pharmacological treatments (e.g. antiplatelets, angiotensin-converting enzyme inhibitors, statins and beta-blockers). Yoga, therefore, could provide a useful frame work on which to develop an economical CR program, with additional advantages of being culturally appropriate to Indians and potentially be appealing to global population.Choroby układu sercowo-naczyniowego są główną przyczyną zgonów i niepełnosprawności mieszkańców Indii, a ponadto mają ogromny wpływ psychologiczny i ekonomiczny, ponieważ często dotykają 30- i 40-latków, wcześniej niechorujących, którzy stanowią najbardziej produktywną grupę społeczną. Skuteczne techniki przezcewnikowe otworzyły nowe perspektywy w leczeniu tych chorób, jednak nie mogą zapobiec ich nawrotom. Z tego względu podstawowe znaczenie ma prewencja wtórna. Rehabilitacja kardiologiczna oparta na jodze (Yoga-CaRe) to wielopłaszczyznowe podejście oddziałujące na sferę fizyczną, psychiczną, społeczną i zawodową, którego celem jest zapobieganie lub spowalnianie progresji choroby podstawowej i obniżenie ryzyka ponownej hospitalizacji lub zgonu, a także poprawa komfortu życia i zachowanie pełnej aktywności. Joga to starożytny hinduski system filozoficzny, którego istotą jest dyscyplina ciała i umysłu i który obejmuje szereg reguł filozoficznych oraz ćwiczeń mentalnych i fizycznych. Spośród siedmiu głównych odmian jogi najbardziej znaną jest Hatha yoga, która również obejmuje wiele różnych rodzajów (tj. Iyenger, Ashtanga etc.) i łączy element ćwiczeń fizycznych, kontroli oddechu i medytacji z samoograniczeniami (dotyczącymi diety, palenia tytoniu, spożywania alkoholu i snu). W przeglądzie danych dostępnych w bazie Cochrane wykazano, że rehabilitacja kardiologiczna (CR) powoduje zmniejszenie o 27% śmiertelności całkowitej oraz o 19% śmiertelności całkowitej i zdarzeń sercowych niezakończonych zgonem, a więc pozwala uzyskać korzystniejsze efekty niż skuteczna farmakoterapia (tj. leki przeciwpłytkowe, inhibitory konwertazy angiotensyny, statyny i antagoniści receptorów beta-adrenergicznych). Joga może być użyteczna jako podstawa do opracowania ekonomicznego program CR, a jej dodatkowym atutem jest zgodność z kulturą Indii i popularność na całym świecie

ANALYSIS OF PSYCHO-SOCIAL RISK FACTORS IN PATIENTS WITH RECENT ACUTE CORONARY SYNDROME: A CASE-CONTROL STUDY

ABSTRACTObjective: Although psycho-social factors are reported to be independently associated with myocardial ischemia in many studies, the majority ofthese were done in the western population. This was conducted in India to determine the impact of psycho-social factors in subjects with the recentacute coronary syndrome (ACS).Methods: Patients with the first episode of ACS within 4 weeks of onset at LPS Institute of Cardiology, Kanpur, India between 2013 and 2015 wereenrolled as cases. Control was community-based individuals without coronary artery disease. Both were compared for demographic variables,the psycho-social profile including annual income, education status, depression, stressful life events (using presumptive stressful life events scale,i.e. PSLES), and independent predictors were determined using multiple logistic regression analysis and were computed as odds ratio (OR).Results: Between 200 cases and 200 controls, respectively, statistically significant difference was observed in mean annual income (2.74±1.95 vs.2.23±1.22 lac rupees; p&lt;0.05), smoking exposure (13.93±16.17 vs. 4.88±3.10 pack years; p&lt;0.05), mean number of stressful life events (8.18±2.57 vs.4.14±1.63; p&lt;0.05). Depression (48% vs. 27%; p&lt;0.05) while education status was comparable. Further, odds of having myocardial infarction werehigher for subjects with mild-to-moderate depression (OR: 2.45), family history of heart disease (OR: 2.25), hypertensive males (OR: 1.43), anddiabetic females (OR: 1.22).Conclusion: Psycho-social factors, particularly depression may have a significant role in the prognosis of ACS. Further systematic studies arewarranted to provide more important insights regarding the magnitude of the association between psycho-social factors and the onset of ACS.Keywords: Coronary artery disease, Depression, Psycho-social factors, Presumptive stressful life events scale, Stressful life events

Valorisation of CO 2 into Value-Added Products via Microbial Electrosynthesis (MES) and Electro-Fermentation Technology

Microbial electrocatalysis reckons on microbes as catalysts for reactions occurring at electrodes. Microbial fuel cells and microbial electrolysis cells are well-known in this context; both prefer the oxidation of organic and inorganic matter for producing electricity. Notably, the synthesis of high energy-density chemicals (fuels) or their precursors by microorganisms using bio-cathode to yield electrical energy is called Microbial Electrosynthesis (MES), giving an exceptionally appealing novel way for producing beneficial products from electricity and wastewater. This review accentuates the concept, importance and opportunities of MES, as an emerging discipline at the nexus of microbiology and electrochemistry. Production of organic compounds from MES is considered as an effective technique for the generation of various beneficial reduced end-products (like acetate and butyrate) as well as in reducing the load of CO2 from the atmosphere to mitigate the harmful effect of greenhouse gases in global warming. Although MES is still an emerging technology, this method is not thoroughly known. The authors have focused on MES, as it is the next transformative, viable alternative technology to decrease the repercussions of surplus carbon dioxide in the environment along with conserving energy

Coronary Angiography Safety between Transradial and Transfemoral Access

Background and Aim. The aim of study was to evaluate safety, feasibility, and procedural variables of transradial approach compared with transfemoral approach in a standard population of patients undergoing coronary catheterization as one of the major criticisms of the transradial approach is that it takes longer overall procedure and fluoroscopy time, thereby causing more radiation exposure. Method. Between January 2015 and December 2015, a total of 1,997 patients in LPS Institute of Cardiology, GSVM Medical College, Kanpur, UP, India, undergoing coronary catheterization were randomly assigned to the transradial or transfemoral approach. Result. Successful catheterization was achieved in 1045 of 1076 patients (97.1%) in the transradial group and in 918 of 921 patients (99.7%) in the transfemoral group (p=0.001). Comparing the transradial and transfemoral approaches, fluoroscopy time (2.46±1.22 versus 2.83±1.31 min; p=0.32), procedure time (8.89±2.72 versus 9.33±2.82 min; p=0.56), contrast volume (67.52±22.54 versus 71.63±25.41 mL; p=0.32), radiation dose as dose area product (24.2±4.21 versus 22.3±3.46 Gycm2; p=0.43), and postprocedural rise of serum creatinine (6±4.5% versus 8±2.6%; p=0.41) were not significantly different while vascular access site complications were significantly lower in transradial group than transfemoral group (3.9% versus 7.6%; p=0.04). Conclusion. The present study shows that transradial access for coronary angiography is safe among patients compared to transfemoral access with lower rate of local vascular complications

Regulatory T Cells Suppress T Cell Activation at the Pathologic Site of Human Visceral Leishmaniasis

Suppression of T cell response is thought to be involved in the pathogenesis of visceral leishmaniasis (VL). Regulatory T cell (Treg) mediated immune-suppression is reported in animal models of Leishmania infection. However, their precise role among human patients still requires pathologic validation. The present study is aimed at understanding the frequency dynamics and function of Treg cells in the blood and bone marrow (BM) of VL patients. The study included 42 parasitologically confirmed patients, 17 healthy contact and 9 normal bone marrow specimens (NBM). We show i) the selective accumulation of Treg cells at one of the disease inflicted site(s), the BM, ii) their in vitro expansion in response to LD antigen and iii) persistence after successful chemotherapy. Results indicate that the Treg cells isolated from BM produces IL-10 and may inhibit T cell activation in IL-10 dependent manner. Moreover, we observed significantly higher levels of IL-10 among drug unresponsive patients, suggesting their critical role in suppression of immunity among VL patients. Our results suggest that IL-10 plays an important role in suppression of host immunity in human VL and possibly determines the efficacy of chemotherapy