Ultrafast pump-probe spectroscopic studies have been performed on (C 5 Me 5 ) 2 U[-NdC(Ph)(CH 2 P... more Ultrafast pump-probe spectroscopic studies have been performed on (C 5 Me 5 ) 2 U[-NdC(Ph)(CH 2 Ph)] 2 and (C 5 Me 5 ) 2 Th[-NdC(Ph)(CH 2 Ph)] 2 including, for the uranium complex, the first direct measurement of dynamics of electronic deactivation within a 5f-electron manifold. Evidence has been found for strong coupling between the electronic ground state and the f-electron manifold which dominates the dynamics of the excited states of the bis(ketimide) uranium complex. These also demonstrate strong singlet-f manifold coupling, which assists in the deactivation of the photoexcited state of the uranium complex, and provide information on intersystem crossing and internal conversion processes in both complexes.
As the head-disk spacing reduces in order to achieve the areal density goal of , the dynamic stab... more As the head-disk spacing reduces in order to achieve the areal density goal of , the dynamic stability of the slider is compromised due to a variety of proximity interactions. Lubricant pickup by the slider from the disk is one of the major reasons for the decrease in the stability as it ...
We envisioned that label-free control of the transport of cells in two dimensions through recepto... more We envisioned that label-free control of the transport of cells in two dimensions through receptorligand interactions would enable simple separation systems that are easy to implement, yet retain the specificity of receptor-ligand interactions. Here we demonstrate nanomechanical control of cell transport in two dimensions via transient receptor-ligand adhesive bonds by patterning of receptors that direct cell rolling through an edge effect. HL-60 cells rolling on P-selectin receptor patterns were deflected at angles of 5 -10° with respect to their direction of travel. Absence of this effect in the case of rigid microsphere models of cell rolling suggests that this twodimensional motion depends on nanomechanical properties of the rolling cell. This work suggests the feasibility of simple continuous-flow microfluidic cell separation systems that minimize processing steps and yet retain the specificity of receptor-ligand interactions.
The peer-to-peer technology offers many advantages, but at the same time, it poses many novel cha... more The peer-to-peer technology offers many advantages, but at the same time, it poses many novel challenges for the research community. Modern peer-to-peer systems are characterized by large scale, poor reliability, and extreme dynamism of the participating nodes, with a continuous flow of nodes joining and leaving the systems. Selection of an optimal network requires estimation of its rank using attributes such as storage, average load, cost, reliability etc. There are multiple networks, each vying for users business by providing them novel services. The user in turn has to decide which network best meets its service requirements and accordingly join a network.
We hypothesized that the cardioprotective effect of angiotensin II (AngII) type 1 receptor (AT(1)... more We hypothesized that the cardioprotective effect of angiotensin II (AngII) type 1 receptor (AT(1)R) blockade during in vivo ischemia-reperfusion (IR) might be associated with an increase in AngII type 2 receptor (AT(2)R) protein, as well as 1,4,5-inositol trisphosphate type 2 receptor (IP(3)R) and protein kinase C(epsilon) (PKC(epsilon)) proteins and cyclic guanosine 3',5' monophosphate (cGMP). We studied the effects of the AT(1)R blocker, candesartan, on in vivo left ventricular (LV) systolic and diastolic function and remodeling (echocardiogram/Doppler) and hemodynamics during canine reperfused anterior infarction (90-minute ischemia, 120-minute reperfusion), and ex vivo infarct size and AT(1)R/AT(2)R, IP(3)R, and PKC(epsilon) proteins (immunoblots), and cGMP (enzyme immunoassay). Compared with controls, candesartan (1 mg/kg intravenously over 30-minute preischemia) inhibited the AngII pressor response, decreased preload and afterload, improved LV systolic and diastolic function, limited LV remodeling, decreased infarct size (55% vs 27% risk; P <.000003), markedly increased AT(2)R, IP(3)R, and PKC(epsilon) proteins in the infarct zone, but not the AT(1)R protein, and increased infarct more than noninfarct cGMP. The overall results suggest that cardioprotective effects of AT(1)R blockade on acute IR injury might involve AT(2)R activation and downstream signaling via IP(3)R, PKC(epsilon), and cGMP.
The Bluetooth specification defines the notion of interconnected piconets, called scatternets, bu... more The Bluetooth specification defines the notion of interconnected piconets, called scatternets, but does not define the actual mechanisms and algorithms necessary to set up and maintain them. The operation of a scatternet requires some Bluetooth units to be interpiconet units (gateways), which need to time-division multiplex their presence among their piconets. This requires a scatternet-scheduling algorithm that can schedule the presence of these units in an efficient manner. In this paper, we propose a distributed scatternet-scheduling scheme that is implemented using the HOLD mode of Bluetooth and adapts to non-uniform and changing traffic. Another attribute of the scheme is that it results in fair allocation of bandwidth to each Bluetooth unit. This scheme provides an integrated solution for both intraand inter-piconet scheduling, i.e., for polling of slaves and scheduling of gateways. He joined the faculty of the UCLA Computer Science Department in 1977. His current research is in the area of analysis, design and control of communication networks. Ongoing projects include the design and evaluation of QoS routing and multicast algorithms for IP domains, the design and evaluation of all-optical network topologies and access protocols, the design of wireless mobile, multimedia networks for mobile computing applications, and the development of measurement methods and tools for evaluating the performance of high-speed networks and applications.
Background: Pollens are important triggers for allergic asthma and seasonal rhinitis, and proteas... more Background: Pollens are important triggers for allergic asthma and seasonal rhinitis, and proteases released by major allergenic pollens can injure airway epithelial cells in vitro. Disruption of mucosal epithelial integrity by proteases released by inhaled pollens could promote allergic sensitisation.
Ultrafast pump-probe spectroscopic studies have been performed on (C 5 Me 5 ) 2 U[-NdC(Ph)(CH 2 P... more Ultrafast pump-probe spectroscopic studies have been performed on (C 5 Me 5 ) 2 U[-NdC(Ph)(CH 2 Ph)] 2 and (C 5 Me 5 ) 2 Th[-NdC(Ph)(CH 2 Ph)] 2 including, for the uranium complex, the first direct measurement of dynamics of electronic deactivation within a 5f-electron manifold. Evidence has been found for strong coupling between the electronic ground state and the f-electron manifold which dominates the dynamics of the excited states of the bis(ketimide) uranium complex. These also demonstrate strong singlet-f manifold coupling, which assists in the deactivation of the photoexcited state of the uranium complex, and provide information on intersystem crossing and internal conversion processes in both complexes.
As the head-disk spacing reduces in order to achieve the areal density goal of , the dynamic stab... more As the head-disk spacing reduces in order to achieve the areal density goal of , the dynamic stability of the slider is compromised due to a variety of proximity interactions. Lubricant pickup by the slider from the disk is one of the major reasons for the decrease in the stability as it ...
We envisioned that label-free control of the transport of cells in two dimensions through recepto... more We envisioned that label-free control of the transport of cells in two dimensions through receptorligand interactions would enable simple separation systems that are easy to implement, yet retain the specificity of receptor-ligand interactions. Here we demonstrate nanomechanical control of cell transport in two dimensions via transient receptor-ligand adhesive bonds by patterning of receptors that direct cell rolling through an edge effect. HL-60 cells rolling on P-selectin receptor patterns were deflected at angles of 5 -10° with respect to their direction of travel. Absence of this effect in the case of rigid microsphere models of cell rolling suggests that this twodimensional motion depends on nanomechanical properties of the rolling cell. This work suggests the feasibility of simple continuous-flow microfluidic cell separation systems that minimize processing steps and yet retain the specificity of receptor-ligand interactions.
The peer-to-peer technology offers many advantages, but at the same time, it poses many novel cha... more The peer-to-peer technology offers many advantages, but at the same time, it poses many novel challenges for the research community. Modern peer-to-peer systems are characterized by large scale, poor reliability, and extreme dynamism of the participating nodes, with a continuous flow of nodes joining and leaving the systems. Selection of an optimal network requires estimation of its rank using attributes such as storage, average load, cost, reliability etc. There are multiple networks, each vying for users business by providing them novel services. The user in turn has to decide which network best meets its service requirements and accordingly join a network.
We hypothesized that the cardioprotective effect of angiotensin II (AngII) type 1 receptor (AT(1)... more We hypothesized that the cardioprotective effect of angiotensin II (AngII) type 1 receptor (AT(1)R) blockade during in vivo ischemia-reperfusion (IR) might be associated with an increase in AngII type 2 receptor (AT(2)R) protein, as well as 1,4,5-inositol trisphosphate type 2 receptor (IP(3)R) and protein kinase C(epsilon) (PKC(epsilon)) proteins and cyclic guanosine 3',5' monophosphate (cGMP). We studied the effects of the AT(1)R blocker, candesartan, on in vivo left ventricular (LV) systolic and diastolic function and remodeling (echocardiogram/Doppler) and hemodynamics during canine reperfused anterior infarction (90-minute ischemia, 120-minute reperfusion), and ex vivo infarct size and AT(1)R/AT(2)R, IP(3)R, and PKC(epsilon) proteins (immunoblots), and cGMP (enzyme immunoassay). Compared with controls, candesartan (1 mg/kg intravenously over 30-minute preischemia) inhibited the AngII pressor response, decreased preload and afterload, improved LV systolic and diastolic function, limited LV remodeling, decreased infarct size (55% vs 27% risk; P <.000003), markedly increased AT(2)R, IP(3)R, and PKC(epsilon) proteins in the infarct zone, but not the AT(1)R protein, and increased infarct more than noninfarct cGMP. The overall results suggest that cardioprotective effects of AT(1)R blockade on acute IR injury might involve AT(2)R activation and downstream signaling via IP(3)R, PKC(epsilon), and cGMP.
The Bluetooth specification defines the notion of interconnected piconets, called scatternets, bu... more The Bluetooth specification defines the notion of interconnected piconets, called scatternets, but does not define the actual mechanisms and algorithms necessary to set up and maintain them. The operation of a scatternet requires some Bluetooth units to be interpiconet units (gateways), which need to time-division multiplex their presence among their piconets. This requires a scatternet-scheduling algorithm that can schedule the presence of these units in an efficient manner. In this paper, we propose a distributed scatternet-scheduling scheme that is implemented using the HOLD mode of Bluetooth and adapts to non-uniform and changing traffic. Another attribute of the scheme is that it results in fair allocation of bandwidth to each Bluetooth unit. This scheme provides an integrated solution for both intraand inter-piconet scheduling, i.e., for polling of slaves and scheduling of gateways. He joined the faculty of the UCLA Computer Science Department in 1977. His current research is in the area of analysis, design and control of communication networks. Ongoing projects include the design and evaluation of QoS routing and multicast algorithms for IP domains, the design and evaluation of all-optical network topologies and access protocols, the design of wireless mobile, multimedia networks for mobile computing applications, and the development of measurement methods and tools for evaluating the performance of high-speed networks and applications.
Background: Pollens are important triggers for allergic asthma and seasonal rhinitis, and proteas... more Background: Pollens are important triggers for allergic asthma and seasonal rhinitis, and proteases released by major allergenic pollens can injure airway epithelial cells in vitro. Disruption of mucosal epithelial integrity by proteases released by inhaled pollens could promote allergic sensitisation.
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