Papers by Abhishek Agarwal
Bookmarks Related papers MentionsView impact
Journal of Radiology Case Reports, 2013
Coronary artery anomalies may involve the origin, course, and structure of epicardial coronary ar... more Coronary artery anomalies may involve the origin, course, and structure of epicardial coronary arteries and occur in less than 1% of the general population. Clinical presentation ranges from being completely asymptomatic to sudden death. Multi-detector computed tomography has come a long way in the diagnosis of coronary artery anomalies since the introduction of 4 rows of detectors in scanners, considering its non invasive nature and the benefits of 3D reconstruction. Defining the coronary anatomy helps in clinical decision making and timely intervention. Since repeated angiographies may be required, low dose CT is an excellent investigation for diagnosis and post interventional follow up rather than repeated invasive catheter angiographies or high dose CT examination. We report two cases of clinically significant single coronary artery anomalies; a case of single Right coronary artery and another case of single Left coronary artery (Anomaly of origin & course).
Bookmarks Related papers MentionsView impact
The Indian Journal of Pediatrics, 2004
Bookmarks Related papers MentionsView impact
Indian Journal of Pediatrics, 2004
Choroid plexus papillomas are rare, benign tumors of neuroectodermal origin usually observed in t... more Choroid plexus papillomas are rare, benign tumors of neuroectodermal origin usually observed in the lateral ventricles of children. The usual presenting signs of choroid plexus papillomas are related to hydrocephalus and increased intracranial pressure. A child presented to us with clinical features of delayed milestones, which was later diagnosed as a case of choroid plexus papilloma with hydrocephalus. He underwent complete excision of the tumour with gradual recovery of milestones.
Bookmarks Related papers MentionsView impact
Nature, 2006
Bookmarks Related papers MentionsView impact
Lab on A Chip, 2007
We present autonomously-triggered on-chip microfluidic cooling devices that utilize thermo-respon... more We present autonomously-triggered on-chip microfluidic cooling devices that utilize thermo-responsive hydrogels to adapt to local environmental temperatures. An external rotating magnetic stirrer couples with an in situ fabricated nickel impeller in these centrifugal-based microfluidic cooling devices to recirculate cooler water. Temperature-responsive hydrogels, which exhibit volumetric expansion and contraction, are integrated at the axle of the impeller. In this design, the hydrogels behave similar to an automotive clutch, to autonomously control the impeller's rotation as a function of the local environmental temperature. Therefore, the hydrogels act as both sensors and actuators and help take away the necessity for additional temperature sensing, feedback, and/or control units here. Cooling devices capable of on-chip thermal management at multiple predetermined onset operation points are realized by changes to the composition of hydrogel to alter its lowest critical solution temperature (LCST). Furthermore, the effect of magnetic stirrer frequency on the fluid cooling and flowrates for different two-blade nickel impeller designs are presented.
Bookmarks Related papers MentionsView impact
Lab on A Chip, 2006
We demonstrate a chemical and biological sensing mechanism in microfluidics that transduces chemi... more We demonstrate a chemical and biological sensing mechanism in microfluidics that transduces chemical and biological signals to electrical signals with large intrinsic amplification without need for complex electronics. The sensing mechanism involves a dissolvable membrane separating a liquid sample chamber from an interdigitated electrode. Dissolution of the membrane (here, a disulfide cross-linked poly(acrylamide) hydrogel) in the presence of a specific target (here, a reducing agent-dithiothreitol) allows the target solution to flow into contact with the electrode. The liquid movement displaces the air dielectric with a liquid, leading to a change (open circuit to approximately 1 kOmega) in the resistance between the electrodes. Thus, a biochemical event is transduced into an electrical signal via fluid movement. The concentration of the target is estimated by monitoring the difference in dissolution times of two juxtaposed sensing membranes having different dissolution characteristics. No dc power is consumed by the sensor until detection of the target. A range of targets could be sensed by defining membranes specific to the target. This sensing mechanism might find applications in sensing targets such as toxins, which exhibit enzymatic activity.
Bookmarks Related papers MentionsView impact
The Indian Journal of Pediatrics, 2004
Bookmarks Related papers MentionsView impact
Journal of Micromechanics and Microengineering, 2006
Page 1. Integration of polymer and metal microstructures using liquid-phase photopolymerization T... more Page 1. Integration of polymer and metal microstructures using liquid-phase photopolymerization This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2006 J. Micromech. Microeng. 16 332 ...
Bookmarks Related papers MentionsView impact
Indian Journal of Pediatrics, 2004
Choroid plexus papillomas are rare, benign tumors of neuroectodermal origin usually observed in t... more Choroid plexus papillomas are rare, benign tumors of neuroectodermal origin usually observed in the lateral ventricles of children. The usual presenting signs of choroid plexus papillomas are related to hydrocephalus and increased intracranial pressure. A child presented to us with clinical features of delayed milestones, which was later diagnosed as a case of choroid plexus papilloma with hydrocephalus. He underwent complete excision of the tumour with gradual recovery of milestones.
Bookmarks Related papers MentionsView impact
IEEE/ASME Journal of Microelectromechanical Systems, 2005
Page 1. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 14, NO. 6, DECEMBER 2005 1409 Programmabl... more Page 1. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 14, NO. 6, DECEMBER 2005 1409 Programmable Autonomous Micromixers and Micropumps Abhishek K. Agarwal, Sudheer S. Sridharamurthy, David ...
Bookmarks Related papers MentionsView impact
Nature, 2006
Bookmarks Related papers MentionsView impact
Nature, 2006
Bookmarks Related papers MentionsView impact
Lab on A Chip, 2007
We present autonomously-triggered on-chip microfluidic cooling devices that utilize thermo-respon... more We present autonomously-triggered on-chip microfluidic cooling devices that utilize thermo-responsive hydrogels to adapt to local environmental temperatures. An external rotating magnetic stirrer couples with an in situ fabricated nickel impeller in these centrifugal-based microfluidic cooling devices to recirculate cooler water. Temperature-responsive hydrogels, which exhibit volumetric expansion and contraction, are integrated at the axle of the impeller. In this design, the hydrogels behave similar to an automotive clutch, to autonomously control the impeller's rotation as a function of the local environmental temperature. Therefore, the hydrogels act as both sensors and actuators and help take away the necessity for additional temperature sensing, feedback, and/or control units here. Cooling devices capable of on-chip thermal management at multiple predetermined onset operation points are realized by changes to the composition of hydrogel to alter its lowest critical solution temperature (LCST). Furthermore, the effect of magnetic stirrer frequency on the fluid cooling and flowrates for different two-blade nickel impeller designs are presented.
Bookmarks Related papers MentionsView impact
Biosensors and Bioelectronics, 2013
Bookmarks Related papers MentionsView impact
Lab on A Chip, 2006
We demonstrate a chemical and biological sensing mechanism in microfluidics that transduces chemi... more We demonstrate a chemical and biological sensing mechanism in microfluidics that transduces chemical and biological signals to electrical signals with large intrinsic amplification without need for complex electronics. The sensing mechanism involves a dissolvable membrane separating a liquid sample chamber from an interdigitated electrode. Dissolution of the membrane (here, a disulfide cross-linked poly(acrylamide) hydrogel) in the presence of a specific target (here, a reducing agent-dithiothreitol) allows the target solution to flow into contact with the electrode. The liquid movement displaces the air dielectric with a liquid, leading to a change (open circuit to approximately 1 kOmega) in the resistance between the electrodes. Thus, a biochemical event is transduced into an electrical signal via fluid movement. The concentration of the target is estimated by monitoring the difference in dissolution times of two juxtaposed sensing membranes having different dissolution characteristics. No dc power is consumed by the sensor until detection of the target. A range of targets could be sensed by defining membranes specific to the target. This sensing mechanism might find applications in sensing targets such as toxins, which exhibit enzymatic activity.
Bookmarks Related papers MentionsView impact
Analytical Chemistry, 2011
In this report, we demonstrate the purification of DNA and RNA from a 10% serum sample using an o... more In this report, we demonstrate the purification of DNA and RNA from a 10% serum sample using an oligonucleotide capture matrix. This approach provides a one-stage, completely aqueous system capable of purifying both RNA and DNA for downstream PCR amplification. The advantages of utilizing the polymer capture matrix method in place of the solid-phase extraction method is that the capture matrix eliminates both guanidine and the 2-propanol wash that can inhibit downstream PCR and competition with proteins for the binding sites that can limit the capacity of the device. This method electrophoreses a biological sample (e.g., serum) containing the nucleic acid target through a polymer matrix with covalently bound oligonucleotides. These capture oligonucleotides selectively hybridize and retain the target nucleic acid, while the other biomolecules and reagents (e.g., SDS) pass through the matrix to waste. Following this purification step, the solution can be heated above the melting temperature of the capture sequence to release the target molecule, which is then electrophoresed to a recovery chamber for subsequent PCR amplification. We demonstrate that the device can be applied to purify both DNA and RNA from serum. The gag region of HIV at a starting concentration of 37.5 copies per microliter was successfully purified from a 10% serum sample demonstrating the applicability of this method to detect viruses present in low copy numbers.
Bookmarks Related papers MentionsView impact
Journal of Micromechanics and Microengineering, 2006
Page 1. Integration of polymer and metal microstructures using liquid-phase photopolymerization T... more Page 1. Integration of polymer and metal microstructures using liquid-phase photopolymerization This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2006 J. Micromech. Microeng. 16 332 ...
Bookmarks Related papers MentionsView impact
IEEE/ASME Journal of Microelectromechanical Systems, 2005
Page 1. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 14, NO. 6, DECEMBER 2005 1409 Programmabl... more Page 1. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 14, NO. 6, DECEMBER 2005 1409 Programmable Autonomous Micromixers and Micropumps Abhishek K. Agarwal, Sudheer S. Sridharamurthy, David ...
Bookmarks Related papers MentionsView impact
Nature, 2006
Bookmarks Related papers MentionsView impact
Uploads
Papers by Abhishek Agarwal