AIM: To compare the atrio-ventricular(AV/PV) delay optimization by echocardiography and intra-cardiac electrocardiogram(IEGM) based Quick Opt algorithm in complete heart block(CHB) patients, implanted with a dual cham...AIM: To compare the atrio-ventricular(AV/PV) delay optimization by echocardiography and intra-cardiac electrocardiogram(IEGM) based Quick Opt algorithm in complete heart block(CHB) patients, implanted with a dual chamber pacemaker. METHODS: We prospectively enrolled 20 patients(age 59.45 ± 18.1 years; male: 65%) with CHB, who were implanted with a dual chamber pacemaker. The left ventricular outflow tract velocity time-integral was measured after AV/PV delay optimization by both echocardiography and Quick Opt algorithm method. Bland-Altman analysis was used for agreement between the two techniques. RESULTS: The optimal AV and PV delay determined by echocardiography was 155.5 ± 14.68 ms and 122.5 ± 17.73 ms(P < 0.0001), respectively and by Quick Opt method was 167.5 ± 16.73 and 117.5 ms ± 9.10 ms(P < 0.0001), respectively. A good agreement was observed between optimal AV and PV delay as measured by two methods. However, the correlation of the optimal AV(r = 0.0689, P = 0.77) and PV(r = 0.2689, P = 0.25) intervals measured by the two techniques was poor. The time required for AV/PV optimization was 45.26 ± 1.73 min by echocardiography and 0.44 ± 0.08 min by Quick Opt method(P < 0.0001).CONCLUSION: The programmer based IEGM method is an automated, quick, easier and reliable alternative to echocardiography for the optimization of AV/PV delay in CHB patients, implanted with a dual chamber pacemaker.展开更多
Rationale:Dengue fever is a prevalent tropical infectious disease that has a broad panorama of presentations from mild febrile illness to life-threatening manifestations in the form of dengue hemorrhagic fever and den...Rationale:Dengue fever is a prevalent tropical infectious disease that has a broad panorama of presentations from mild febrile illness to life-threatening manifestations in the form of dengue hemorrhagic fever and dengue shock syndrome.Patient’s concerns:A 20-year-old male presented with a 2-day history of fever,multiple episodes of vomiting,and altered sensorium.Diagnosis:Dengue fever leading to acute hemorrhagic leukoencephalitis.Interventions:Multiple transfusions of single donor platelets,intravenous methylprednisolone,intravenous immunoglobulin,anti-seizure prophylaxis,and broad-spectrum antibiotics.Outcomes:Repeat brain magnetic resonance imaging showed resolution of lesions.The patient was subsequently discharged from the hospital in a healthy state.Lessons:This report helps us to gain a better understanding of the patient’s presentation,which will help to improve the timely recognition and prevention of this rare devastating presentation.展开更多
The effect of river runoff over the northern Indian Ocean(NIO) especially over the Bay of Bengal(Bo B) has been studied using global Nucleus for European Modelling of the Ocean(NEMO). Two sensitivity experiments, with...The effect of river runoff over the northern Indian Ocean(NIO) especially over the Bay of Bengal(Bo B) has been studied using global Nucleus for European Modelling of the Ocean(NEMO). Two sensitivity experiments, with and without river runoff are conducted and the influence of river runoff on the Indian Ocean hydrography,stratification and circulation features are studied. It is found that due to river runoff surface salinity over the northern Bo B decreases by more than 5 and the East India Coastal Current strengthens by 2 cm/s during post monsoon season. The fresh river water reaches up to 15°N in the Bo B and is the main cause for low salinity there.Sea surface temperature in the northwestern Bo B increases by more than 0.2℃ due to the river runoff in summer monsoon while surface cooling upto 0.2℃ is seen in north-west part of Bo B in winter season. The seasonal mixed layer depth in the region is found to be dependent on river runoff. The effect of vertical shear and Brunt Vaisala frequency on stratification is also examined. The ocean water becomes highly stratified up to 3 035 m due to the river runoff. It is found that the energy required for mixing is high in the northern and coastal Bo B.展开更多
In this work,a non-classical analytical approach for buckling analysis of partially cracked generally orthotropic plate is proposed under the thermal domain.The derivation for the governing equation is based on the no...In this work,a non-classical analytical approach for buckling analysis of partially cracked generally orthotropic plate is proposed under the thermal domain.The derivation for the governing equation is based on the non-classical approach using Kirchhoff’s thin plate theory and the modified couple stress theory.The effect of fibre orientation on critical buckling temperature is incorporated by considering the coefficients of mutual influence.Line spring model is applied with some modifications to formulate all the crack terms while the thermal effects are introduced in form of thermal in-plane moments and forces.The final governing equation is solved using Galerkin’s method and the relation for critical buckling temperature as affected by fibre orientation is obtained.The variation of critical buckling temperature as affected by fibre orientation for different values of crack length,crack location and length scale parameter is presented.Also,the effect of fibre orientation on fundamental frequency under the thermal domain is analysed.展开更多
Ultra high molecular weight polyethylene (UHMWPE) is widely used for articulating surfaces in total hip and knee replacements. In the present work, UHMWPE based polymer composites were synthesized by synergistic rei...Ultra high molecular weight polyethylene (UHMWPE) is widely used for articulating surfaces in total hip and knee replacements. In the present work, UHMWPE based polymer composites were synthesized by synergistic reinforcing of bioactive hydroxyapatite (HA), bioinert aluminum oxide (Al2O3), and carbon nanotubes (CNTs) using compression molding. Phase and microstructural analysis suggests retention of UHMWPE and reinforcing phases in the compression molded composites. Microstructural analysis elicited variation in densification due to the size effect of the reinforcing particles. The hybrid composites exhibited hardness, elastic modulus and toughness comparable to that of UHMWPE. The interfacial effect of reinforcement phases has evinced the effectiveness of Al2O3 over HA and CNT reinforcements, depicting synergistic enhancement in hardness and elastic modulus. Weak interfacial bonding of polymer matrix with HA and CNT requires utilization of coupling agents to achieve enhanced mechanical properties without deteriorating cytocompatible properties.展开更多
Nickel-gamma alumina(Ni—γAI2O3) composite coatings were synthesized by pulsed electrodeposition technique with different concentrations of alumina(0,10,20 and 50 g/L) in Watt’s bath.Both ultrasonic vibration an...Nickel-gamma alumina(Ni—γAI2O3) composite coatings were synthesized by pulsed electrodeposition technique with different concentrations of alumina(0,10,20 and 50 g/L) in Watt’s bath.Both ultrasonic vibration and magnetic-stirring were utilized to disperse Al2O3 and to achieve its optimum loading.Microstructure shows that agglomerates occur at higher loadings,but 10 g/L Al2O3 addition in bath has shown uniform dispersion of alumina with improved mechanical properties such as hardness,Young’s modulus and yield strength by 40%,46%and 35%,respectively,when compared to that of pure Ni coating.Further,elasto-plastic indentation mechanics has shown that strength at 29%strain is enhanced to 110.5 GPa for 10 g/L Al2O3electrophoretically deposited Ni—yAI2O3 coating when compared to that of electrodeposited Ni(81.8 GPa).展开更多
文摘AIM: To compare the atrio-ventricular(AV/PV) delay optimization by echocardiography and intra-cardiac electrocardiogram(IEGM) based Quick Opt algorithm in complete heart block(CHB) patients, implanted with a dual chamber pacemaker. METHODS: We prospectively enrolled 20 patients(age 59.45 ± 18.1 years; male: 65%) with CHB, who were implanted with a dual chamber pacemaker. The left ventricular outflow tract velocity time-integral was measured after AV/PV delay optimization by both echocardiography and Quick Opt algorithm method. Bland-Altman analysis was used for agreement between the two techniques. RESULTS: The optimal AV and PV delay determined by echocardiography was 155.5 ± 14.68 ms and 122.5 ± 17.73 ms(P < 0.0001), respectively and by Quick Opt method was 167.5 ± 16.73 and 117.5 ms ± 9.10 ms(P < 0.0001), respectively. A good agreement was observed between optimal AV and PV delay as measured by two methods. However, the correlation of the optimal AV(r = 0.0689, P = 0.77) and PV(r = 0.2689, P = 0.25) intervals measured by the two techniques was poor. The time required for AV/PV optimization was 45.26 ± 1.73 min by echocardiography and 0.44 ± 0.08 min by Quick Opt method(P < 0.0001).CONCLUSION: The programmer based IEGM method is an automated, quick, easier and reliable alternative to echocardiography for the optimization of AV/PV delay in CHB patients, implanted with a dual chamber pacemaker.
文摘Rationale:Dengue fever is a prevalent tropical infectious disease that has a broad panorama of presentations from mild febrile illness to life-threatening manifestations in the form of dengue hemorrhagic fever and dengue shock syndrome.Patient’s concerns:A 20-year-old male presented with a 2-day history of fever,multiple episodes of vomiting,and altered sensorium.Diagnosis:Dengue fever leading to acute hemorrhagic leukoencephalitis.Interventions:Multiple transfusions of single donor platelets,intravenous methylprednisolone,intravenous immunoglobulin,anti-seizure prophylaxis,and broad-spectrum antibiotics.Outcomes:Repeat brain magnetic resonance imaging showed resolution of lesions.The patient was subsequently discharged from the hospital in a healthy state.Lessons:This report helps us to gain a better understanding of the patient’s presentation,which will help to improve the timely recognition and prevention of this rare devastating presentation.
文摘The effect of river runoff over the northern Indian Ocean(NIO) especially over the Bay of Bengal(Bo B) has been studied using global Nucleus for European Modelling of the Ocean(NEMO). Two sensitivity experiments, with and without river runoff are conducted and the influence of river runoff on the Indian Ocean hydrography,stratification and circulation features are studied. It is found that due to river runoff surface salinity over the northern Bo B decreases by more than 5 and the East India Coastal Current strengthens by 2 cm/s during post monsoon season. The fresh river water reaches up to 15°N in the Bo B and is the main cause for low salinity there.Sea surface temperature in the northwestern Bo B increases by more than 0.2℃ due to the river runoff in summer monsoon while surface cooling upto 0.2℃ is seen in north-west part of Bo B in winter season. The seasonal mixed layer depth in the region is found to be dependent on river runoff. The effect of vertical shear and Brunt Vaisala frequency on stratification is also examined. The ocean water becomes highly stratified up to 3 035 m due to the river runoff. It is found that the energy required for mixing is high in the northern and coastal Bo B.
文摘In this work,a non-classical analytical approach for buckling analysis of partially cracked generally orthotropic plate is proposed under the thermal domain.The derivation for the governing equation is based on the non-classical approach using Kirchhoff’s thin plate theory and the modified couple stress theory.The effect of fibre orientation on critical buckling temperature is incorporated by considering the coefficients of mutual influence.Line spring model is applied with some modifications to formulate all the crack terms while the thermal effects are introduced in form of thermal in-plane moments and forces.The final governing equation is solved using Galerkin’s method and the relation for critical buckling temperature as affected by fibre orientation is obtained.The variation of critical buckling temperature as affected by fibre orientation for different values of crack length,crack location and length scale parameter is presented.Also,the effect of fibre orientation on fundamental frequency under the thermal domain is analysed.
基金funded by the Department of Biotechnology (DBT),Govt.of India
文摘Ultra high molecular weight polyethylene (UHMWPE) is widely used for articulating surfaces in total hip and knee replacements. In the present work, UHMWPE based polymer composites were synthesized by synergistic reinforcing of bioactive hydroxyapatite (HA), bioinert aluminum oxide (Al2O3), and carbon nanotubes (CNTs) using compression molding. Phase and microstructural analysis suggests retention of UHMWPE and reinforcing phases in the compression molded composites. Microstructural analysis elicited variation in densification due to the size effect of the reinforcing particles. The hybrid composites exhibited hardness, elastic modulus and toughness comparable to that of UHMWPE. The interfacial effect of reinforcement phases has evinced the effectiveness of Al2O3 over HA and CNT reinforcements, depicting synergistic enhancement in hardness and elastic modulus. Weak interfacial bonding of polymer matrix with HA and CNT requires utilization of coupling agents to achieve enhanced mechanical properties without deteriorating cytocompatible properties.
基金financial support from Ministry of Human Resource Development
文摘Nickel-gamma alumina(Ni—γAI2O3) composite coatings were synthesized by pulsed electrodeposition technique with different concentrations of alumina(0,10,20 and 50 g/L) in Watt’s bath.Both ultrasonic vibration and magnetic-stirring were utilized to disperse Al2O3 and to achieve its optimum loading.Microstructure shows that agglomerates occur at higher loadings,but 10 g/L Al2O3 addition in bath has shown uniform dispersion of alumina with improved mechanical properties such as hardness,Young’s modulus and yield strength by 40%,46%and 35%,respectively,when compared to that of pure Ni coating.Further,elasto-plastic indentation mechanics has shown that strength at 29%strain is enhanced to 110.5 GPa for 10 g/L Al2O3electrophoretically deposited Ni—yAI2O3 coating when compared to that of electrodeposited Ni(81.8 GPa).