Abstract Helicases represent a special class of enzymes which separate the double helix of the nu... more Abstract Helicases represent a special class of enzymes which separate the double helix of the nucleic acid (RNA or DNA) by harnessing energy from ATP hydrolysis and are, therefore important for every aspect of DNA and RNA metabolism. A variety of genomes, including malaria parasite, has been sequenced. The proteome is much more complex, diverse, and vast as compared to the genome. The posttranslational modifications (PTMs) are responsible for this vibrant dynamics and complexity of the proteome. PTMs are basically chemical changes of the structure of protein due to the action of the enzyme specific to the substrate. PTMs play a crucial role in diversifying the biological functions of several proteins, including helicases. In this chapter, an in silico analysis of the PTMs of biochemically characterized helicases of Plasmodium falciparum is presented.
Malaria is one of the major global health concerns still prevailing in this 21st century. Even th... more Malaria is one of the major global health concerns still prevailing in this 21st century. Even the effect of artemisinin combination therapies (ACT) have declined and causing more mortality across the globe. Therefore, it is important to understand the basic biology of malaria parasite in order to find novel drug targets. Helicases play important role in nucleic acid metabolism and are components of cellular machinery in various organisms. In this manuscript we have performed the biochemical characterization of homologue of DDX17 from Plasmodium falciparum (PfDDX17). Our results show that PfDDX17 is an active RNA helicase and uses mostly ATP for its function. The qRT-PCR experiment results suggest that PfDDX17 is highly expressed in the trophozoite stage and it is localised mainly in the cytoplasm and in infected RBC (iRBC) membrane mostly in the trophozoite stage. The dsRNA knockdown study suggests that PfDDX17 is important for cell cycle progression. These studies report the biochemical functions of PfDDX17 helicase and further augment the fundamental knowledge about helicase families of P. falciparum.
Soft pneumatic actuators have been explored for endoscopic applications, but challenges in fabric... more Soft pneumatic actuators have been explored for endoscopic applications, but challenges in fabricating complex geometry with desirable dimensions and compliance remain. The addition of an endoscopic camera or tool channel is generally not possible without significant change in the diameter of the actuator. Radial expansion and ballooning of actuator walls during bending is undesirable for endoscopic applications. The inclusion of strain limiting methods like, wound fibre, mesh, or multi-material molding have been explored, but the integration of these design approaches with endoscopic requirements drastically increases fabrication complexity, precluding reliable translation into functional endoscopes. For the first time in soft robotics, we present a multi-channel, single material elastomeric actuator with a fully corrugated design (inspired by origami); offering specific functionality for endoscopic applications. The features introduced in this design include i) fabrication of mult...
Trans-oral laser microsurgery (TLM) is a surgical procedure for removing malignancies (e.g., cyst... more Trans-oral laser microsurgery (TLM) is a surgical procedure for removing malignancies (e.g., cysts, polyps, tumors) of the laryngeal region through laser ablation. Intraoperative microsurgical forceps (i.e., microforceps) are used for tissue manipulation. The microforceps are rigid, single degree-of-freedom (DOF) devices (open–close) with precurved jaws to access different parts of the curved cylindrical laryngeal region. These microforceps are manually handled and are subject to hand tremors, poor reachability, and nonergonomic use, resulting in poor efficacy and efficiency in the surgery. A novel 3DOF motorized microforceps device is presented here, integrated with a 6DOF serial robotic manipulator. The device, referred to as RMF-3, offers three motorized DOFs: (i) open–close forceps jaw; (ii) tool rotation; and (iii) tool-tip articulation. It is designed to be compliant with TLM spatial constraints. The manual handling is replaced by tele-operation device, the omega.7. The design...
International Journal of Computer Assisted Radiology and Surgery, 2018
Site of research and experiments: The research was carried out at the Istituto Italiano di Tecnol... more Site of research and experiments: The research was carried out at the Istituto Italiano di Tecnologia (IIT) in Genova, Italy. Funding: The study did not receive any external funding. Conflict of Interest: The authors declare that they have no conflict of interest. Ethical approval: For this type of study, formal ethics approval was not required. The Ethics Committee of Liguria Region granted the exemption for the use of human subjects and ex-vivo pig larynxes for the trials. Informed consent: Informed consent was obtained from all individual participants included in the study.
Plasmodium falciparum is responsible for most dangerous and prevalent form of malaria. The emerge... more Plasmodium falciparum is responsible for most dangerous and prevalent form of malaria. The emergence of multi drug resistant parasite hindered the prevention of malaria burden worldwide. Helicases are omnipresent enzymes, which play important role in nucleic acid metabolism and can be used as potential targets for development of novel therapeutics. The genome wide analysis of P. falciparum 3D7 strain revealed some novel parasite specific helicases, which are not present in human host. Here we report the detailed biochemical characterization of P. falciparum parasite specific helicase 3 (PfPSH3). The characteristic ATPase and helicase activities of PfPSH3 reside in its N-terminal region (PfPSH3N) as it contains all the conserved signature motifs whereas the C-terminal does not show any detectable biochemical activity. PfPSH3N also shows DNA helicase activity in the 3'-5' direction. The immunofluorescence microscopy results show that PSH3 is localized in nucleus as well as in ...
2016 IEEE International Conference on Advanced Intelligent Mechatronics (AIM), 2016
Transoral Laser Microsurgeries (TLM) are complex otolaryngological procedures requiring the surge... more Transoral Laser Microsurgeries (TLM) are complex otolaryngological procedures requiring the surgeons to perform intraoperative tissue manipulation with great level of control, accuracy and precision. The process involves the use of a surgical laser to treat abnormalities in the throat without any external incisions. The best removal of the malignant tissue is possible only with coordinated control of the laser aiming for incision and the microsurgical tools for orienting and stretching the tissue. However, the traditional microsurgical tools are long, single purpose, one degree-of-freedom (DOF), rigid tools with small range of motion and a traditional grasping handle inducing non-ergonomic usage. Additionally, there are different variety of microsurgical tools with different modes of actuation for the forceps jaws, i.e. in one mode push action of inner translating rod closes the forceps jaws and in other mode the same action opens the jaws. This paper presents a novel, modular microsurgical tool design to overcome the challenges of the traditional tools and improve the surgeon-tool usage experience. The novel design adds a rotational DOF to expand the reach and functionality of the tool. The device is provided with an ergonomic grasping handle that avoids extreme wrist excursions. A straight line motion mechanism is synthesized such that it is capable of adapting to the variety of tools used in TLM within the same device design. This mechanism was validated by ADAMS simulation as well. The proposed new design adds benefits of functional and ergonomic usage for the surgeons, potentially simplifying the surgical tasks.
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2015
Robot-assisted needle-based surgeries are sought to improve many operations, from brain surgery t... more Robot-assisted needle-based surgeries are sought to improve many operations, from brain surgery to spine and urological procedures. Force feedback from a needle can provide important guidance during needle insertion. This paper presents a new modelling method of needle force during insertion into soft tissue based on finite element simulation. This is achieved by analysing the results of a series of needle inserting experiments with different insertion velocities. The forces acting on the needle are then modelled based on the experimental results. A simulation is implemented to verify the designed model.
Proceedings of the Indian National Science Academy, 2015
The identification of the Toll receptor in Drosophila was a major discovery which restructured th... more The identification of the Toll receptor in Drosophila was a major discovery which restructured the paradigm in immunity as well as developmental biology. Toll homologues are present in mammals where they regulate only immunity. However, in flies, same Toll pathway controls two disparate biological processes like embryonic dorso-ventral patterning and humoral immune response. Toll activation by Spätzle is preceded by a proteolytic cascade which is differently regulated in immunity and embryonic development. Signalling downstream to Toll is similar in both processes and eventually leads to the activation of Drosophila homologues of NF-κB proteins; Dorsal and DIF. Toll pathway, in the early embryo results in graded expression of Dorsal protein leading to Dorso-Ventral axis patterning. On the other hand, activation of Toll-Dorsal pathway in the fat-body leads to induction of antibacterial proteins in larval and adult stages. Here, we review the current status of our knowledge of Dorsal pathway in embryonic development and immunity with special emphasis to regulation of target gene/s of the two pathways by Dorsal.
Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia,... more Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, August 1–5, 2004.
Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia,... more Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, August 1–5, 2004.
The ductility and creep of bulk ultra-fine-grained (UFG) 5083 Al (grain size ;440 nm) processed b... more The ductility and creep of bulk ultra-fine-grained (UFG) 5083 Al (grain size ;440 nm) processed by gas atomization, cryomilling, and consolidation were studied in the temperature range 523 to 648 K. Also, the creep microstructure developed in the alloy was examined by means of transmission electron microscopy (TEM). The ductility as a function of strain rate exhibits a maximum that shifts to higher strain rates with increasing temperature. An analysis of the experimental data indicates that the true stress exponent is about 2, and the true activation energy is close to that anticipated for boundary diffusion in 5083 Al. These creep characteristics along with the ductility behavior of 5083 Al are a reflection of its creep behavior as a superplastic alloy and not as a solid-solution alloy. In addition, the observation of elongations of more than 300 pct at strain rates higher than 0.1 s À1 is indicative of the occurrence of high-strain-rate (HSR) superplasticity. Microstructural evidence for the occurrence of HSR superplasticity includes the retention of equiaxed grains after deformation, the observation of features associated with the occurrence of grain boundary sliding, and the formation of cavity stringers. Grain size stability during the superplastic deformation of the alloy is attributed to the presence of dispersion particles that are introduced during gas spraying and cryomilling. These particles also serve as obstacles for dislocation motion, which may account for the threshold stress estimated from the creep data of the alloy.
Thermal stability in bulk ultrafine-grained (UFG) 5083 Al that was processed by gas atomization f... more Thermal stability in bulk ultrafine-grained (UFG) 5083 Al that was processed by gas atomization followed by cryomilling, consolidation, and extrusion, and that exhibited an average grain size of 305 nm, was investigated in the temperature range of 473 to 673 K (0.55 to 0.79 T m , where T m is the melting temperature of the material) for different annealing times. Appreciable grain growth was observed at temperatures Ͼ573 K, whereas there was limited grain growth at temperatures Ͻ573 K even after long annealing times. The values of the grain growth exponent, n, deduced from the grain growth data were higher than the value of 2 predicted from elementary grain growth theories. The discrepancy was attributed to the operation of strong pinning forces on boundaries during the annealing treatment. An examination of the microstructure of the alloy suggests that the origin of the pinning forces is most likely related to the presence of dispersion particles, which are mostly introduced during cryomilling. Two-grain growth regimes were identified: the low-temperature region (Ͻ573 K) and the high-temperature region (Ͼ573 K). For temperatures lower than 573 K, the activation energy of 25 Ϯ 5 kJ/mol was determined. It is suggested that this low activation energy represents the energy for the reordering of grain boundaries in the UFG material. For temperatures higher than 573 K, an activation energy of 124 Ϯ 5 kJ/mol was measured. This value of activation energy, 124 Ϯ 5 kJ/mol, lies between that for grain boundary diffusion and lattice diffusion in analogous aluminum polycrystalline systems. The results show that the strength and ductility of bulk UFG 5083 Al, as obtained from tensile tests, correlate well with substructural changes introduced in the alloy by the annealing treatment.
Creep behavior and deformation-induced grain growth in electrodeposited (ED) nanocrystalline (nc)... more Creep behavior and deformation-induced grain growth in electrodeposited (ED) nanocrystalline (nc) Ni with a grain size of about 20 nm were studied over more than five orders of magnitude of strain rate (10−9 s−1 to 2×10−4 s−1) at 393 K (0.23 T m, where T mis the melting point). In addition, the activation energy for the creep in ED nc-Ni
Abstract In the present investigation, the occurrence of Harper–Dorn creep in Pb was studied unde... more Abstract In the present investigation, the occurrence of Harper–Dorn creep in Pb was studied under the condition of large strains. In performing the study, two Pb grades, commercial-purity Pb (99.95 pct) and high-purity Pb (99.999 pct), were creep tested at 573 ...
Grain growth behavior of bulk nanocrystalline Ni, prepared by an electrodeposition technique with... more Grain growth behavior of bulk nanocrystalline Ni, prepared by an electrodeposition technique with average grain sizes of 20 and 15 nm was investigated in the homologous temperature (T/T m) range of 0.20-0.40. In studying grain growth, the techniques of X-ray diffraction and transmission electron microscopy were used. The results show that in the temperature range of 0.20-0.30T m , there is no appreciable grain growth, even after long annealing times. However, in the temperature range of 0.3-0.4T m , the rate of grain growth was rapid during the initial period of annealing, which decreases with increase in time. The value of time exponent, n, deduced from the grain growth equation of the general form D 1/n − D 1/n 0 = Kt was found to be approximately 0.1 for both grain sizes of Ni. At temperatures higher than 0.3T m , an approximate activation energy of 105 ± 3 kJ/mol, which is close to the activation energy for grain boundary diffusion in polycrystalline Ni, was measured. At temperatures lower than 0.3T m , an approximate activation energy of 11 ± 3 kJ/mol was found. It is suggested that this low activation energy represents the energy for the reordering of the nanocrystalline grain boundaries.
Journal of the American College of Cardiology, 2004
This study was designed to evaluate the effect of periprocedural myocardial infarction (MI) on mo... more This study was designed to evaluate the effect of periprocedural myocardial infarction (MI) on mortality according to success of the stent procedure. BACKGROUND The mortality effect of periprocedural MI relative to successful versus unsuccessful procedures has not been examined. METHODS All-cause mortality during the first year was evaluated prospectively among 5,850 patients from coronary stent clinical trials. Myocardial infarction was classified according to creatine kinase-MB level as type 1 (Ͼ1 but Ͻ3 times normal), type 2 (Ն3 but Յ8 times normal), or type 3 (Ͼ8 times normal or Q-wave MI). Procedures were classified as successful unless there was a final diameter stenosis Ͼ50%; final Thrombolysis In Myocardial Infarction flow grade Ͻ3; final National Heart, Lung, and Blood Institute dissection grade ՆD; repeat revascularization within 24 h; or stent thrombosis within 24 h. RESULTS Myocardial infarction was more frequent after unsuccessful procedures (69.6% vs. 20.4%, p Ͻ 0.001). Mortality during the first year was higher in patients with MI (2.8% vs. 1.7%, p ϭ 0.01), but the effect was significant only for type 3 MI (4.7% vs. 1.7%, p ϭ 0.008). Moreover, the mortality difference for any MI was confined to patients with unsuccessful procedures (13.1% vs. 0%, p ϭ 0.03), with no significant effect among patients with otherwise successful procedures (2.1% vs. 1.7%, p Ͼ 0.20). The independent predictors of mortality were unsuccessful procedure (p Ͻ 0.001), diabetes mellitus (p ϭ 0.001), history of prior MI (p ϭ 0.003), multivessel disease (p ϭ 0.006), and advancing age (p Ͻ 0.001), but not periprocedural MI. CONCLUSIONS The association of periprocedural MI with increased mortality during the first year following stent placement was confined to patients with unsuccessful procedures.
IOP Conference Series: Materials Science and Engineering, 2010
... illumination variation KC Jondhale 1 and LM Waghmare 2 1 Mahatma Gandhi Mission's Colleg... more ... illumination variation KC Jondhale 1 and LM Waghmare 2 1 Mahatma Gandhi Mission's College of Engineering, Nanded (MS) India 2 Shri Guru Gobind Singhji Institute of Engineering and Technology, Vishnupuri, Nanded (MS) India ...
Percutaneous coronary intervention (PCI) is frequently performed in elderly patients, but little ... more Percutaneous coronary intervention (PCI) is frequently performed in elderly patients, but little is known about its impact on overall health and quality of life. To examine changes in health-related quality of life among elderly patients after PCI. Observational study. 75 U.S. hospitals. Participants in two clinical trials of PCI. Health-related quality of life was assessed by using the Medical Outcomes Study Short Form (SF-36) survey and the Seattle Angina Questionnaire at baseline, 6 months, and 1 year. Serial data on health-related quality of life were available for 295 elderly (> or =70 years) and 1150 nonelderly (<70 years) patients. At 6 months, physical health had improved in 51% of elderly patients and mental health had improved in 29%. Cardiovascular-specific health status had improved in 58% to 75% of elderly patients. Improvement did not significantly differ between elderly and non-elderly patients at 6 months or 1 year. Elderly patients selected for participation in a trial of PCI had substantial improvements in health-related quality of life after PCI that were similar to those in younger patients.
Abstract Helicases represent a special class of enzymes which separate the double helix of the nu... more Abstract Helicases represent a special class of enzymes which separate the double helix of the nucleic acid (RNA or DNA) by harnessing energy from ATP hydrolysis and are, therefore important for every aspect of DNA and RNA metabolism. A variety of genomes, including malaria parasite, has been sequenced. The proteome is much more complex, diverse, and vast as compared to the genome. The posttranslational modifications (PTMs) are responsible for this vibrant dynamics and complexity of the proteome. PTMs are basically chemical changes of the structure of protein due to the action of the enzyme specific to the substrate. PTMs play a crucial role in diversifying the biological functions of several proteins, including helicases. In this chapter, an in silico analysis of the PTMs of biochemically characterized helicases of Plasmodium falciparum is presented.
Malaria is one of the major global health concerns still prevailing in this 21st century. Even th... more Malaria is one of the major global health concerns still prevailing in this 21st century. Even the effect of artemisinin combination therapies (ACT) have declined and causing more mortality across the globe. Therefore, it is important to understand the basic biology of malaria parasite in order to find novel drug targets. Helicases play important role in nucleic acid metabolism and are components of cellular machinery in various organisms. In this manuscript we have performed the biochemical characterization of homologue of DDX17 from Plasmodium falciparum (PfDDX17). Our results show that PfDDX17 is an active RNA helicase and uses mostly ATP for its function. The qRT-PCR experiment results suggest that PfDDX17 is highly expressed in the trophozoite stage and it is localised mainly in the cytoplasm and in infected RBC (iRBC) membrane mostly in the trophozoite stage. The dsRNA knockdown study suggests that PfDDX17 is important for cell cycle progression. These studies report the biochemical functions of PfDDX17 helicase and further augment the fundamental knowledge about helicase families of P. falciparum.
Soft pneumatic actuators have been explored for endoscopic applications, but challenges in fabric... more Soft pneumatic actuators have been explored for endoscopic applications, but challenges in fabricating complex geometry with desirable dimensions and compliance remain. The addition of an endoscopic camera or tool channel is generally not possible without significant change in the diameter of the actuator. Radial expansion and ballooning of actuator walls during bending is undesirable for endoscopic applications. The inclusion of strain limiting methods like, wound fibre, mesh, or multi-material molding have been explored, but the integration of these design approaches with endoscopic requirements drastically increases fabrication complexity, precluding reliable translation into functional endoscopes. For the first time in soft robotics, we present a multi-channel, single material elastomeric actuator with a fully corrugated design (inspired by origami); offering specific functionality for endoscopic applications. The features introduced in this design include i) fabrication of mult...
Trans-oral laser microsurgery (TLM) is a surgical procedure for removing malignancies (e.g., cyst... more Trans-oral laser microsurgery (TLM) is a surgical procedure for removing malignancies (e.g., cysts, polyps, tumors) of the laryngeal region through laser ablation. Intraoperative microsurgical forceps (i.e., microforceps) are used for tissue manipulation. The microforceps are rigid, single degree-of-freedom (DOF) devices (open–close) with precurved jaws to access different parts of the curved cylindrical laryngeal region. These microforceps are manually handled and are subject to hand tremors, poor reachability, and nonergonomic use, resulting in poor efficacy and efficiency in the surgery. A novel 3DOF motorized microforceps device is presented here, integrated with a 6DOF serial robotic manipulator. The device, referred to as RMF-3, offers three motorized DOFs: (i) open–close forceps jaw; (ii) tool rotation; and (iii) tool-tip articulation. It is designed to be compliant with TLM spatial constraints. The manual handling is replaced by tele-operation device, the omega.7. The design...
International Journal of Computer Assisted Radiology and Surgery, 2018
Site of research and experiments: The research was carried out at the Istituto Italiano di Tecnol... more Site of research and experiments: The research was carried out at the Istituto Italiano di Tecnologia (IIT) in Genova, Italy. Funding: The study did not receive any external funding. Conflict of Interest: The authors declare that they have no conflict of interest. Ethical approval: For this type of study, formal ethics approval was not required. The Ethics Committee of Liguria Region granted the exemption for the use of human subjects and ex-vivo pig larynxes for the trials. Informed consent: Informed consent was obtained from all individual participants included in the study.
Plasmodium falciparum is responsible for most dangerous and prevalent form of malaria. The emerge... more Plasmodium falciparum is responsible for most dangerous and prevalent form of malaria. The emergence of multi drug resistant parasite hindered the prevention of malaria burden worldwide. Helicases are omnipresent enzymes, which play important role in nucleic acid metabolism and can be used as potential targets for development of novel therapeutics. The genome wide analysis of P. falciparum 3D7 strain revealed some novel parasite specific helicases, which are not present in human host. Here we report the detailed biochemical characterization of P. falciparum parasite specific helicase 3 (PfPSH3). The characteristic ATPase and helicase activities of PfPSH3 reside in its N-terminal region (PfPSH3N) as it contains all the conserved signature motifs whereas the C-terminal does not show any detectable biochemical activity. PfPSH3N also shows DNA helicase activity in the 3'-5' direction. The immunofluorescence microscopy results show that PSH3 is localized in nucleus as well as in ...
2016 IEEE International Conference on Advanced Intelligent Mechatronics (AIM), 2016
Transoral Laser Microsurgeries (TLM) are complex otolaryngological procedures requiring the surge... more Transoral Laser Microsurgeries (TLM) are complex otolaryngological procedures requiring the surgeons to perform intraoperative tissue manipulation with great level of control, accuracy and precision. The process involves the use of a surgical laser to treat abnormalities in the throat without any external incisions. The best removal of the malignant tissue is possible only with coordinated control of the laser aiming for incision and the microsurgical tools for orienting and stretching the tissue. However, the traditional microsurgical tools are long, single purpose, one degree-of-freedom (DOF), rigid tools with small range of motion and a traditional grasping handle inducing non-ergonomic usage. Additionally, there are different variety of microsurgical tools with different modes of actuation for the forceps jaws, i.e. in one mode push action of inner translating rod closes the forceps jaws and in other mode the same action opens the jaws. This paper presents a novel, modular microsurgical tool design to overcome the challenges of the traditional tools and improve the surgeon-tool usage experience. The novel design adds a rotational DOF to expand the reach and functionality of the tool. The device is provided with an ergonomic grasping handle that avoids extreme wrist excursions. A straight line motion mechanism is synthesized such that it is capable of adapting to the variety of tools used in TLM within the same device design. This mechanism was validated by ADAMS simulation as well. The proposed new design adds benefits of functional and ergonomic usage for the surgeons, potentially simplifying the surgical tasks.
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2015
Robot-assisted needle-based surgeries are sought to improve many operations, from brain surgery t... more Robot-assisted needle-based surgeries are sought to improve many operations, from brain surgery to spine and urological procedures. Force feedback from a needle can provide important guidance during needle insertion. This paper presents a new modelling method of needle force during insertion into soft tissue based on finite element simulation. This is achieved by analysing the results of a series of needle inserting experiments with different insertion velocities. The forces acting on the needle are then modelled based on the experimental results. A simulation is implemented to verify the designed model.
Proceedings of the Indian National Science Academy, 2015
The identification of the Toll receptor in Drosophila was a major discovery which restructured th... more The identification of the Toll receptor in Drosophila was a major discovery which restructured the paradigm in immunity as well as developmental biology. Toll homologues are present in mammals where they regulate only immunity. However, in flies, same Toll pathway controls two disparate biological processes like embryonic dorso-ventral patterning and humoral immune response. Toll activation by Spätzle is preceded by a proteolytic cascade which is differently regulated in immunity and embryonic development. Signalling downstream to Toll is similar in both processes and eventually leads to the activation of Drosophila homologues of NF-κB proteins; Dorsal and DIF. Toll pathway, in the early embryo results in graded expression of Dorsal protein leading to Dorso-Ventral axis patterning. On the other hand, activation of Toll-Dorsal pathway in the fat-body leads to induction of antibacterial proteins in larval and adult stages. Here, we review the current status of our knowledge of Dorsal pathway in embryonic development and immunity with special emphasis to regulation of target gene/s of the two pathways by Dorsal.
Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia,... more Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, August 1–5, 2004.
Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia,... more Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, August 1–5, 2004.
The ductility and creep of bulk ultra-fine-grained (UFG) 5083 Al (grain size ;440 nm) processed b... more The ductility and creep of bulk ultra-fine-grained (UFG) 5083 Al (grain size ;440 nm) processed by gas atomization, cryomilling, and consolidation were studied in the temperature range 523 to 648 K. Also, the creep microstructure developed in the alloy was examined by means of transmission electron microscopy (TEM). The ductility as a function of strain rate exhibits a maximum that shifts to higher strain rates with increasing temperature. An analysis of the experimental data indicates that the true stress exponent is about 2, and the true activation energy is close to that anticipated for boundary diffusion in 5083 Al. These creep characteristics along with the ductility behavior of 5083 Al are a reflection of its creep behavior as a superplastic alloy and not as a solid-solution alloy. In addition, the observation of elongations of more than 300 pct at strain rates higher than 0.1 s À1 is indicative of the occurrence of high-strain-rate (HSR) superplasticity. Microstructural evidence for the occurrence of HSR superplasticity includes the retention of equiaxed grains after deformation, the observation of features associated with the occurrence of grain boundary sliding, and the formation of cavity stringers. Grain size stability during the superplastic deformation of the alloy is attributed to the presence of dispersion particles that are introduced during gas spraying and cryomilling. These particles also serve as obstacles for dislocation motion, which may account for the threshold stress estimated from the creep data of the alloy.
Thermal stability in bulk ultrafine-grained (UFG) 5083 Al that was processed by gas atomization f... more Thermal stability in bulk ultrafine-grained (UFG) 5083 Al that was processed by gas atomization followed by cryomilling, consolidation, and extrusion, and that exhibited an average grain size of 305 nm, was investigated in the temperature range of 473 to 673 K (0.55 to 0.79 T m , where T m is the melting temperature of the material) for different annealing times. Appreciable grain growth was observed at temperatures Ͼ573 K, whereas there was limited grain growth at temperatures Ͻ573 K even after long annealing times. The values of the grain growth exponent, n, deduced from the grain growth data were higher than the value of 2 predicted from elementary grain growth theories. The discrepancy was attributed to the operation of strong pinning forces on boundaries during the annealing treatment. An examination of the microstructure of the alloy suggests that the origin of the pinning forces is most likely related to the presence of dispersion particles, which are mostly introduced during cryomilling. Two-grain growth regimes were identified: the low-temperature region (Ͻ573 K) and the high-temperature region (Ͼ573 K). For temperatures lower than 573 K, the activation energy of 25 Ϯ 5 kJ/mol was determined. It is suggested that this low activation energy represents the energy for the reordering of grain boundaries in the UFG material. For temperatures higher than 573 K, an activation energy of 124 Ϯ 5 kJ/mol was measured. This value of activation energy, 124 Ϯ 5 kJ/mol, lies between that for grain boundary diffusion and lattice diffusion in analogous aluminum polycrystalline systems. The results show that the strength and ductility of bulk UFG 5083 Al, as obtained from tensile tests, correlate well with substructural changes introduced in the alloy by the annealing treatment.
Creep behavior and deformation-induced grain growth in electrodeposited (ED) nanocrystalline (nc)... more Creep behavior and deformation-induced grain growth in electrodeposited (ED) nanocrystalline (nc) Ni with a grain size of about 20 nm were studied over more than five orders of magnitude of strain rate (10−9 s−1 to 2×10−4 s−1) at 393 K (0.23 T m, where T mis the melting point). In addition, the activation energy for the creep in ED nc-Ni
Abstract In the present investigation, the occurrence of Harper–Dorn creep in Pb was studied unde... more Abstract In the present investigation, the occurrence of Harper–Dorn creep in Pb was studied under the condition of large strains. In performing the study, two Pb grades, commercial-purity Pb (99.95 pct) and high-purity Pb (99.999 pct), were creep tested at 573 ...
Grain growth behavior of bulk nanocrystalline Ni, prepared by an electrodeposition technique with... more Grain growth behavior of bulk nanocrystalline Ni, prepared by an electrodeposition technique with average grain sizes of 20 and 15 nm was investigated in the homologous temperature (T/T m) range of 0.20-0.40. In studying grain growth, the techniques of X-ray diffraction and transmission electron microscopy were used. The results show that in the temperature range of 0.20-0.30T m , there is no appreciable grain growth, even after long annealing times. However, in the temperature range of 0.3-0.4T m , the rate of grain growth was rapid during the initial period of annealing, which decreases with increase in time. The value of time exponent, n, deduced from the grain growth equation of the general form D 1/n − D 1/n 0 = Kt was found to be approximately 0.1 for both grain sizes of Ni. At temperatures higher than 0.3T m , an approximate activation energy of 105 ± 3 kJ/mol, which is close to the activation energy for grain boundary diffusion in polycrystalline Ni, was measured. At temperatures lower than 0.3T m , an approximate activation energy of 11 ± 3 kJ/mol was found. It is suggested that this low activation energy represents the energy for the reordering of the nanocrystalline grain boundaries.
Journal of the American College of Cardiology, 2004
This study was designed to evaluate the effect of periprocedural myocardial infarction (MI) on mo... more This study was designed to evaluate the effect of periprocedural myocardial infarction (MI) on mortality according to success of the stent procedure. BACKGROUND The mortality effect of periprocedural MI relative to successful versus unsuccessful procedures has not been examined. METHODS All-cause mortality during the first year was evaluated prospectively among 5,850 patients from coronary stent clinical trials. Myocardial infarction was classified according to creatine kinase-MB level as type 1 (Ͼ1 but Ͻ3 times normal), type 2 (Ն3 but Յ8 times normal), or type 3 (Ͼ8 times normal or Q-wave MI). Procedures were classified as successful unless there was a final diameter stenosis Ͼ50%; final Thrombolysis In Myocardial Infarction flow grade Ͻ3; final National Heart, Lung, and Blood Institute dissection grade ՆD; repeat revascularization within 24 h; or stent thrombosis within 24 h. RESULTS Myocardial infarction was more frequent after unsuccessful procedures (69.6% vs. 20.4%, p Ͻ 0.001). Mortality during the first year was higher in patients with MI (2.8% vs. 1.7%, p ϭ 0.01), but the effect was significant only for type 3 MI (4.7% vs. 1.7%, p ϭ 0.008). Moreover, the mortality difference for any MI was confined to patients with unsuccessful procedures (13.1% vs. 0%, p ϭ 0.03), with no significant effect among patients with otherwise successful procedures (2.1% vs. 1.7%, p Ͼ 0.20). The independent predictors of mortality were unsuccessful procedure (p Ͻ 0.001), diabetes mellitus (p ϭ 0.001), history of prior MI (p ϭ 0.003), multivessel disease (p ϭ 0.006), and advancing age (p Ͻ 0.001), but not periprocedural MI. CONCLUSIONS The association of periprocedural MI with increased mortality during the first year following stent placement was confined to patients with unsuccessful procedures.
IOP Conference Series: Materials Science and Engineering, 2010
... illumination variation KC Jondhale 1 and LM Waghmare 2 1 Mahatma Gandhi Mission's Colleg... more ... illumination variation KC Jondhale 1 and LM Waghmare 2 1 Mahatma Gandhi Mission's College of Engineering, Nanded (MS) India 2 Shri Guru Gobind Singhji Institute of Engineering and Technology, Vishnupuri, Nanded (MS) India ...
Percutaneous coronary intervention (PCI) is frequently performed in elderly patients, but little ... more Percutaneous coronary intervention (PCI) is frequently performed in elderly patients, but little is known about its impact on overall health and quality of life. To examine changes in health-related quality of life among elderly patients after PCI. Observational study. 75 U.S. hospitals. Participants in two clinical trials of PCI. Health-related quality of life was assessed by using the Medical Outcomes Study Short Form (SF-36) survey and the Seattle Angina Questionnaire at baseline, 6 months, and 1 year. Serial data on health-related quality of life were available for 295 elderly (> or =70 years) and 1150 nonelderly (<70 years) patients. At 6 months, physical health had improved in 51% of elderly patients and mental health had improved in 29%. Cardiovascular-specific health status had improved in 58% to 75% of elderly patients. Improvement did not significantly differ between elderly and non-elderly patients at 6 months or 1 year. Elderly patients selected for participation in a trial of PCI had substantial improvements in health-related quality of life after PCI that were similar to those in younger patients.
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