Genotype-phenotype associations in patients with severe hyperinsulinism of infancy (2007)
Greer, RM, Shah, J, Jeske, YW, Brown, D, Walker, RM, Cowley, D, ...
In hyperinsulinism of infancy (HI), unregulated insulin secretion causes hypoglycemia. Pancreatectomy may be required in severe cases, most of which result from a defect in the beta-cell K-ATP...
Genotype-Phenotype associations in patients with severe hyperinsulinism of infancy (2007)
Greer, R.M., Shah, J., Jeske, Y.W., Brown, D., Walker, R., Cowley, D., ...
In hyperinsulinism of infancy (HI), unregulated insulin secretion causes hypoglycemia. Pancreatectomy may be required in severe cases, most of which result from a defect in the beta-cell K-ATP...
A pictorial essay - imaging in surgical jaundice (2006)
Patel, N, Parekh, H, Vasavada, D, Mehta, S, Porecha, M, Shah, J
Oral physiology to pathology: learning lesson from tobacco related oral lesions (2004)
Bhatt, Janardan, Shah, J., Falguni, S.
It is concluded that the prevalence of malignant lesions were significantly high amongst tobacco users compared to non tobacco users .Oral consumption of tobacco is significant health hazard...
Clinico-pathological profile of cervical lymphadenopathy (2000)
Bhatt, Janardan, Shah, J., Shah, F.
The study concluded the fact that the tuberculosis is the most common cause of cervical lymphadenopathy. In our set up 51.9 % of patient of CL were suffering from tuberculous cervical lymphadenitis....
Hallervorden Spatz disease: MR imaging. (1999)
Shah, J, Patkar, D, Patankar, T, Krishnan, A, Prasad, S, Limdi, J
Giant rheumatoid synovial cyst of the hip joint: diagnosed by MRI. (1999)
Patkar, D, Shah, J, Prasad, S, Patankar, T, Gokhale, S, Krishnan, A, ...
MR imaging in children with ectopic pituitary gland and anterior hypopituitarism. (1999)
Patkar, D, Patankar, T, Krishnan, A, Prasad, S, Shah, J, Limdi, J
Ruptured intracranial dermoids: magnetic resonance imaging. (1999)
Patkar, D, Krishnan, A, Patankar, T, Prasad, S, Shah, J, Limdi, J
Pedunculated nasal glioma: MRI features and review of the literature. (1999)
Shah, J, Patkar, D, Patankar, T, Krishnan, A, Prasad, S, Limdi, J
Several major areas of current research activities in the field of Hot Carriers maybe identified from the program of this conference. The ability to grow high quality micro- and nano- structures usng...
Schäfer, W., Shah, J., Damen, T.C., Cunningham, J.E., Goossen, K.W., ...
We present a unified microscopic approach to four-wave mixing (FWM) in semiconductors on an ultrashort time scale. The theory is valid for resonant excitation in the vicinity of the excitonic...
Energy use, emissions, and air pollution reduction strategies in Asia. (1995)
Foell, W., Green, C., Amann, M., Bhattacharya, S., Carmichael, G., Chadwick, M., ...
Löser, F., Klatt, D., Leo, K., Bakker, H., Shah, J., ...
The polarization and population dynamics of resonantly generated excitions in GaAs/AlGaAs quantum well structures are investigated using transient three-pulse four-wave mixing. The decay dynamics...
Bakker, H.J., Leo, K., Shah, J., Köhler, K.
We present an experimental and theoretical study of the dephasing of heavy-hole excitons in a 70 Angström GaAs/AlxGa1-xAs multiple-quantum-well structure. We measure the time-integrated threepulse...
Schneider, H., Vinattieri, A., Shah, J., Ehret, S., Larkins, E.C., Rossmanith, M.
We have investigated electron and hole capture times in n-type double-barrier quantum well (DBQW) infrared (3-5 mym) detector structures. Photoluminescence upconversion allows us to observe the...
Shah, J., Damen, T.C., Schäfer, W., Pfeiffer, L.N., Köhler, K.
We show the existence of an instantaneous contribution to the time-resolved four-wave mixing (FWM) from GaAs quantum wells near zero time delay ( T = 0), which is very sensitive to the excitation...
Schneider, H., Ehret, S., Vinattieri, A., Shah, J., Larkins, E.C.
We report on the carrier dynamics in n-type double-barrier quantum well structures in an electric field. Both the intersubband and interband photocurrents, excited by long-wavelength (4 mym) and...
Coherent excitonic effects in quantum wells (1993)
Coherent transient spectroscopy of semiconductor nanostructures has become an active field of research in recent years. Most such experiments are analyzed in terms of a simple two-level model in...
Picosecond photoluminescence of resonantly-excited excitons in GaAs quantum wells (1993)
Vinattieri, A., Shah, J., Damen, T., Kim, D., Pfeiffer, L., Sham, L.
We show that the initial dynamics of resonantly-excited excitons in quantum wells is controlled by several processes such as radiative recombination, spin relaxation of excitons, electrons and holes,...
Coherent excitonic effects in quantum wells (1993)
Coherent transient spectroscopy of semiconductor nanostructures has become an active field of research in recent years. Most such experiments are analyzed in terms of a simple two-level model in...
Picosecond photoluminescence of resonantly-excited excitons in GaAs quantum wells (1993)
Vinattieri, A., Shah, J., Damen, T., Kim, D., Pfeiffer, L., Sham, L.
We show that the initial dynamics of resonantly-excited excitons in quantum wells is controlled by several processes such as radiative recombination, spin relaxation of excitons, electrons and holes,...
Coherent excitonic effects in quantum wells (1993)
Coherent transient spectroscopy of semiconductor nanostructures has become an active field of research in recent years. Most such experiments are analyzed in terms of a simple two-level model in...
Picosecond photoluminescence of resonantly-excited excitons in GaAs quantum wells (1993)
Vinattieri, A., Shah, J., Damen, T., Kim, D., Pfeiffer, L., Sham, L.
We show that the initial dynamics of resonantly-excited excitons in quantum wells is controlled by several processes such as radiative recombination, spin relaxation of excitons, electrons and holes,...
Terahertz radiation from coherent electron oscillations in a double-quantum-well structure. (1993)
Roskos, H.G., Nuss, M.C., Shah, J., Leo, K., Miller, D.A.B., Schmitt-Rink, S., ...
We detect the submillimeter-wave radiation from excitonic wave packets that, after excitation by an ultrashort laser pulse, oscillate coherently between the two wells of a semiconductor...
Observation of Bloch oscillations in a semiconductor superlattice (1993)
Haring Bolivar, P., Leisching, P., Leo, K., Shah, J., Köhler, K.
We investigate the polarization decay in biased superlattices with transient degenerate four-wave mixing. The signals have a strong periodic modulation in the field regime where the cw optical...
Coupling of exciton transitions associated with different quantum-well islands (1993)
Koch, M., Feldmann, J., Göbel, E.O., Thomas, P., Shah, J., Köhler, K.
We show by means of time-resolved four-wave-mixing experiments that the simultaneous excitation of energetically distinct and inhomogenously broadened exciton transitions associated with spatially...
Schäfer, W., Jahnke, F., Damen, T.C., Köhler, K., Schmitt-Rink, S., ...
Four-wave-mixing signals from excitions in high-quality GaAs quantum wells show an unusually slow temporal evolution, in stark contrast to the behavior expected for a noninteracting two-level system....
Subpicosecond spectroscopy of excitons in GaAs/AlGaAs heterostructures (1992)
Leo, K., Shah, J., Schmitt-Rink, S., Köhler, K.
We study the dynamics of excitons in GaAs/AlGaAs quantum wells using time-resolved self-diffracted four-wave-mixing. We discuss two topics: First, we show that the decay of the diffracted signal is...
Quantum beats of excitons in quantum wells (1992)
Schmitt-Rink, S., Damen, T., Göbel, E.O., Köhler, K., Leo, K., Schäfer, W., ...
We review our observations of quantum beats of excitons in quantum wells arising from (i) heavy hole-light hole splitting, (ii) exciton splitting due to fluctuations in the well-width of quantum...
Polarization dependence of heavy- and light-hole quantum beats (1992)
Schmitt-Rink, S., Bennhardt, D., Heuckeroth, V., Thomas, P., Haring, P., Maidorn, G., ...
Simultaneous excitation of heavy- and light-hole quantum-well excitions with linearly polarized ultrashort laser pulses results in oscillating four-wave-mixing and pump-probe signals. These are...
Dissipative dynamics of an electronic wavepacket in a semiconductor double well potential. (1992)
Schulze, A., Meier, T., Thomas, P., Luo, M.S.C., Schäfer, W., Chuang, S.L., ...
We present a detailed study of coherent tunneling oscillations of an optically excited electronic wavepacket in a semiconductor double quantum-well structure. The oscillation of the wavepacket...
Coherent submillimeter-wave emission from charge oscillations in a double-well potential (1992)
Roskos, H.G., Nuss, M.C., Miller, D.A.B., Köhler, K., Leo, K., Schmitt-Rink, S., ...
We directly observe the electromagnetic radiation emitted by electrons coherently oscillating between the two wells of a semiconductor coupled-quantum- well structure. Using time-resolved coherent...
Terahertz absorption between split subbands in coupled Quantum Wells. (1991)
Cunningham, J., Köhler, K., Nuss, M.C., Roskos, H., Shah, J., Tell, B.
The transition between split subbands (design splitting: 5 meV) in n-doped coupled quantum wells is investigated by time-domain spectroscopy with ultrafast pulses of far-infrared radiation. This very...
Subpicosecond four-wave mixing in GaAs/Al(x)Ga(1-x)As quantum wells (1991)
Leo, K., Shah, J., Schmitt-Rink, S., Schäfer, W., Müller, J.F., Damen, T.C., ...
We investigate the properties of coherent exciton states in GaAs/AlxGa1-xAs quantum wells using the four-wave-mixing technique with subpicosecond time resolution. In the first part of this work, we...
Resonant tunneling in double quantum wells - the cases of strong and weak collisions. (1991)
Leo, K., Shah, J., Schmitt-Rink, S., Schäfer, W., Damen, T.C., Göbel, E.O., ...
Quantum beats of excitons in quantum wells (1991)
Leo, K., Shah, J., Schmitt-Rink, S., Schäfer, W., Müller, J.F., Köhler, K., ...
We briefly review or recent observations of quantum beats of excitons in quantum wells. The quantum beats are observed as an oscillatory structure in the polarization decay of energetically closely...
Coherent oscillations of a wave packet in a semiconductor double-quantum-well structure (1991)
Damen, T.C., Göbel, E.O., Köhler, K., Leo, K., Schäfer, W., Schmitt-Rink, S., ...
We present the first observation of the spatial dynamics of a wavepacket in a solid. Using an ultrashort laser pulse, we create an excitonic wavepacket in one well of an asymmetric double quantum...
Tunneling in semiconductor heterostructures studied by subpicosecond four-wave mixing. (1990)
Damen, T.C., Ganser, P., Göbel, E.O., Köhler, K., Leo, K., Shah, J.
We apply time-resolved four-wave mixing as novel tool to study resonant tunneling of carriers in semiconductor heterostructures. The polarization decay of excitons in a quantum well is much faster...
Damen, T.C., Ganser, P., Göbel, E.O., Köhler, K., Leo, K., Shah, J.
We introduce sub-picosecond transient four-wave-mixing techniques as a novel tool to optically study resonant tunneling in semiconductor heterostructures. The resonant carrier transfer in an...
Quantum beats of light hole and heavy hole excitons in quantum wells. (1990)
Damen, T.C., Köhler, K., Leo, K., Shah, J.
We report the first observation of quantum beats due to the interference of the polarization decay of heavy hole and light hole excitons in semiconductor quantum wells.
Quantum beats of free and bound excitons in GaAs/Al(x)Ga(1-x)As quantum wells (1990)
Leo, K., Shah, J., Köhler, K., Damen, T.C.
We report the observation of quantum beats in the decay of the coherent polarization of intrinsic excitations in GaAs/GaAlAs quantum wells. The beating arises from interference of excitons with...
Quantum beats from extended electronic states in quantum wells (1990)
Müller, J.F., Schmitt-Rink, S., Schäfer, W., Damen, T.C., Ganser, P., Göbel, E.O., ...
We study the polarization decay of excitons in GaAs/AlGaAs quantum wells using timeresolved degenerate-four-wave-mixing (DFWM) with subpicosecond time resolution. The coherent excitation of two...
Femtosecond transient-grating experiments in quantum wells (1990)
Schmitt-Rink, S., Müller, J.F., Damen, T.C., Ganser, P., Göbel, E.O., Köhler, K., ...
Using degenerate four-wave mixing (DFWM) with subpicosecond timeresolution, we demonstrate the following phenomena: (I) a novel coherent interaction of excitonic polarizations and (II) quantum beats...
Platelet function and blood coagulation in tetanus. (1981)
Manikeri, S, Kshirsagar, N, Karandikar, S, Dastur, F, Awatramani, V, Shah, J, ...
INVESTIGATION OF HOT CARRIER RELAXATION WITH PICOSECOND LASER PULSES (1981)
Recent availability of subpicosecond lasers has enhanced the usefulness of optical techniques in the investigation of hot carrier relaxation in semiconductors by allowing us to directly probe the...
TIME RESOLVED OPTICAL SPECTROSCOPY IN AMORPHOUS SILICON AND CHALCOGENIDES (1981)
Time resolved optical spectroscopy has become a valuable technique for studying the nature of electronic states in solids. Over the past few years, amorphous solids have been investigated using a...
INVESTIGATION OF HOT CARRIER RELAXATION WITH PICOSECOND LASER PULSES (1981)
Recent availability of subpicosecond lasers has enhanced