Optimization of Virtual Shack-Hartmann Wavefront Sensing

Virtual Shack–Hartmann wavefront sensing (vSHWS) can flexibly adjust parameters to meet different requirements without changing the system, and it is a promising means for aberration measurement. However, how to optimize its parameters to achieve the best performance is rarely discussed. In this work, the data processing procedure and methods of vSHWS were demonstrated by using a set of normal human ocular aberrations as an example. The shapes (round and square) of a virtual lenslet, the zero-padding of the sub-aperture electric field, sub-aperture number, as well as the sequences (before and after diffraction calculation), algorithms, and interval of data interpolation, were analyzed to find the optimal configuration. The effect of the above optimizations on its anti-noise performance was also studied. The Zernike coefficient errors and the root mean square of the wavefront error between the reconstructed and preset wavefronts were used for performance evaluation. The performance of the optimized vSHWS could be significantly improved compared to that of a non-optimized one, which was also verified with 20 sets of clinical human ocular aberrations. This work makes the vSHWS’s implementation clearer, and the optimization methods and the obtained results are of great significance for its applications.

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Ticlopidine Facilitates the Deaggregation of Human Platelets Aggregated by Thrombin

Thrombosis and Haemostasis ◽

10.1055/s-0038-1642389 ◽

1994 ◽

Vol 71 (01) ◽

pp. 091-094 ◽

Cited By ~ 15

Author(s):

M Cattaneo ◽

B Akkawat ◽

R L Kinlough-Rathbone ◽

M A Packham ◽

C Cimminiello ◽

...

Keyword(s):

Cardiovascular Disease ◽

Platelet Aggregation ◽

Prostaglandin E1 ◽

Human Platelet ◽

Adenosine Diphosphate ◽

Human Platelets ◽

Before And After ◽

Normal Human ◽

Platelet Aggregates ◽

Induced Aggregation

SummaryNormal human platelets aggregated by thrombin undergo the release reaction and are not readily deaggregated by the combination of inhibitors hirudin, prostaglandin E1 (PGE1) and chymotrypsin. Released adenosine diphosphate (ADP) plays an important role in the stabilization of thrombin-induced human platelet aggregates. Since ticlopidine inhibits the platelet responses to ADP, we studied thrombin-induced aggregation and deaggregation of 14C-serotonin-labeled platelets from 12 patients with cardiovascular disease before and 7 days after the oral administration of ticlopidine, 250 mg b.i.d. Before and after ticlopidine, platelets stimulated with 1 U/ml thrombin aggregated, released about 80–90% 14C-serotinin and did not deaggregate spontaneously within 5 min from stimulation. Before ticlopidine, hirudin (5× the activity of thrombin) and PGE1 (10 μmol/1) plus chymotrypsin (10 U/ml) or plasmin (0.06 U/ml), added at the peak of platelet aggregation, caused slight or no platelet deaggregation. After ticlopidine, the extent of platelet deaggregation caused by the same inhibitors was significantly greater than before ticlopidine. The addition of ADP (10 μmol/1) to platelet suspensions 5 s after thrombin did not prevent the deaggregation of ticlopidine-treated platelets. Thus, ticlopidine facilitates the deaggregation of thrombin-induced human platelet aggregates, most probably because it inhibits the effects of ADP on platelets.

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Electro-haptic hearing: Speech-in-noise performance in cochlear implant users is enhanced by tactile stimulation of the wrists

10.31234/osf.io/j6bn4 ◽

2019 ◽

Author(s):

Mark D. Fletcher ◽

Amatullah Hadeedi ◽

Tobias Goehring ◽

Sean R Mills

Keyword(s):

Cochlear Implant ◽

Speech Intelligibility ◽

Tactile Stimulation ◽

Electrical Signal ◽

Noise Performance ◽

Speech In Noise ◽

Non Invasive ◽

Real World Application ◽

Before And After ◽

Stimulation Of

Cochlear implant (CI) users receive only limited sound information through their implant, which means that they struggle to understand speech in noisy environments. Recent work has suggested that combining the electrical signal from the CI with a haptic signal that provides crucial missing sound information (“electro-haptic stimulation”; EHS) could improve speech-in-noise performance. The aim of the current study was to test whether EHS could enhance speech-in-noise performance in CI users using: (1) a tactile signal derived using an algorithm that could be applied in real time, (2) a stimulation site appropriate for a real-world application, and (3) a tactile signal that could readily be produced by a compact, portable device. We measured speech intelligibility in multi-talker noise with and without vibro-tactile stimulation of the wrist in CI users, before and after a short training regime. No effect of EHS was found before training, but after training EHS was found to improve the number of words correctly identified by an average of 8.3 %-points, with some users improving by more than 20 %-points. Our approach could offer an inexpensive and non-invasive means of improving speech-in-noise performance in CI users.

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STUDIES ON HUMAN ADRENAL STEROIDS: 1. THE EFFECT OF CORTICOTROPIN ON COMPONENTS OF THE FREE AND CONJUGATED PLASMA C2l ADRENAL STEROID FRACTIONS

Canadian Journal of Biochemistry and Physiology ◽

10.1139/o56-018 ◽

1956 ◽

Vol 34 (2) ◽

pp. 146-157 ◽

Cited By ~ 9

Author(s):

C. M. Southcott ◽

S. K. Gandossi ◽

A. D. Barker ◽

H. E. Bandy ◽

Hamish McIntosh ◽

...

Keyword(s):

Individual Variation ◽

Preliminary Data ◽

Plasma Levels ◽

Adrenal Steroids ◽

Adrenal Steroid ◽

Peripheral Plasma ◽

Before And After ◽

Normal Human ◽

Considerable Individual Variation

The free and conjugated adrenal steroid fractions of peripheral plasma from12 normal human males were studied. Specimens were withdrawn before and after the administration of corticotropin. Hydrocortisone was identified chemically and some evidence was obtained for the presence of corticosterone. Hydrocortisone levels showed a marked but variable increase after corticotropin treatment. In some cases the administration of corticotropin resulted in the appearance of an unconjugated compound which may have been a tetrahydro derivative of cortisone or hydrocortisone. A method for studying the conjugated fraction was developed and preliminary data indicated that four components were present in some specimens after hydrolysis with β-glucuronidase. The level of these conjugates appeared to increase after treatment with corticotropin. In general, the response to a given dose of corticotropin showed considerable individual variation in the plasma levels of the components of both the free and conjugated corticosteroid fractions.

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Bronchodilatation, lung recoil, and density dependence of maximal expiratory flow

Journal of Applied Physiology ◽

10.1152/jappl.1982.52.4.874 ◽

1982 ◽

Vol 52 (4) ◽

pp. 874-878 ◽

Cited By ~ 4

Author(s):

J. W. Weiss ◽

E. R. McFadden ◽

R. H. Ingram

Keyword(s):

Density Dependence ◽

Vital Capacity ◽

Human Subjects ◽

Beta Agonist ◽

Elastic Recoil ◽

Maximal Expiratory Flow ◽

Before And After ◽

Normal Human ◽

Expiratory Flow ◽

Expiratory Flow Rates

Using normal human subjects we have measured maximal expiratory flow rates with air (Vmaxair) and after a washin of 80% He-20% O2 (VmaxHeO2) and static elastic recoil pressures of the lung [Pst(L)] both before and after administration of a beta-agonist, terbutaline. The effects of inhaled drug were compared with those of the subcutaneously administered agent, each given in doses to produce maximal bronchodilatation as assessed by increases in Vmaxair in the mid-vital capacity. Although there was a significant yet modest decrease in Pst(L) only after injection of the agent, density dependence (DD), assessed as the ratio of VmaxHeO2 to Vmaxair, increased significantly and comparably after either route of administration. A modest decrease in Pst(L), therefore, did not affect the changes in DD.

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Analysis on parameter switching methods for hydropower dominant system

E3S Web of Conferences ◽

10.1051/e3sconf/202124203003 ◽

2021 ◽

Vol 242 ◽

pp. 03003

Author(s):

Shengjing She ◽

Chongtao Li ◽

Yiping Chen ◽

Rongzhao Yang ◽

Liang Xiao ◽

...

Keyword(s):

Time Domain ◽

Frequency Control ◽

Rapid Development ◽

Optimization Methods ◽

Time Domain Simulation ◽

Before And After ◽

Primary Frequency ◽

Switching Method ◽

Primary Frequency Control ◽

Parameter Switching

With the rapid development of DC asynchronous interconnection, in order to ensure the frequency quality, higher requirements are put forward for the primary frequency control of hydropower units. In the high proportion hydropower system, it is difficult for the governor parameters to meet the requirements of primary frequency control and dynamic stability simultaneously. In order to solve the problem, this paper proposes a recommended parameter switching method by referring to the Nordic system. The parameter optimization methods before and after switching are proposed, and the effectiveness of the method is verified by time domain simulation.

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Aminophylline and human diaphragm strength in vivo

Journal of Applied Physiology ◽

10.1152/jappl.1990.68.6.2591 ◽

1990 ◽

Vol 68 (6) ◽

pp. 2591-2596 ◽

Cited By ~ 19

Author(s):

R. D. Levy ◽

S. Nava ◽

L. Gibbons ◽

F. Bellemare

Keyword(s):

Motor Units ◽

Normal Subjects ◽

Acute Administration ◽

Transdiaphragmatic Pressure ◽

Gastric Pressure ◽

Significant Difference ◽

Before And After ◽

Normal Human ◽

Twitch Characteristics

The transdiaphragmatic pressure (Pdi) twitch response to single shocks from supramaximal bilateral phrenic nerve stimulation was studied before and after acute intravenous infusions of aminophylline [14.9 +/- 3.1 (SD) micrograms/ml] in nine normal subjects. Stimulation was performed with subjects in the sitting position against an occluded airway from end expiration. Baseline gastric pressure and abdominal and rib cage configuration were kept constant. There was no significant difference in peak twitch Pdi from the relaxed diaphragm between control (38.8 +/- 3.3 cmH2O) and aminophylline (40.2 +/- 5.2 cmH2O) experiments. Other twitch characteristics including contraction time, half-relaxation time, and maximum relaxation rate were also unchanged. The Pdi-twitch amplitude at different levels of voluntary Pdi was measured with the twitch occlusion technique, and this relationship was found to be similar under control conditions and after aminophylline. With this technique, maximum Pdi (Pdimax) was calculated as the Pdi at which stimulation would result in no Pdi twitch because all motor units are already maximally activated. No significant change was found in mean calculated Pdimax between control (146.9 +/- 27.0 cmH2O) and aminophylline (149.2 +/- 26.0 cmH2O) experiments. We conclude from this study that the acute administration of aminophylline at therapeutic concentrations does not significantly affect contractility or maximum strength of the normal human diaphragm in vivo.

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Evidence for Extracellular Processing of Pro-von Willebrand Factor After Infusion in Animals With and Without Severe von Willebrand Disease

Blood ◽

10.1182/blood.v94.5.1637 ◽

1999 ◽

Vol 94 (5) ◽

pp. 1637-1647 ◽

Cited By ~ 17

Author(s):

P.L. Turecek ◽

L. Pichler ◽

W. Auer ◽

G. Eder ◽

K. Varadi ◽

...

Keyword(s):

Von Willebrand Factor ◽

Von Willebrand Disease ◽

Proteolytic Processing ◽

Enzyme Linked Immunosorbent Assay ◽

Targeted Disruption ◽

Agarose Gels ◽

Before And After ◽

Normal Human ◽

Von Willebrand ◽

Willebrand Factor

Abstract Although proteolytic processing of pro-von Willebrand factor (pro-vWF) resulting in free propeptide and mature vWF is known to be initiated intracellularly, vWF released from endothelial cells may contain a high proportion of incompletely processed pro-vWF. Because pro-vWF is only rarely detectable in normal human plasma, we investigated whether extracellular processing of pro-vWF is possible. A recombinant preparation (rpvWF) containing both pro-vWF and mature vWF subunits was infused into 2 pigs and 1 dog with severe von Willebrand disease, 2 mice with a targeted disruption of the vWF gene, and 2 healthy baboons. Total vWF antigen (vWF:Ag), free propeptide, and pro-vWF were measured using enzyme-linked immunosorbent assay techniques in blood samples drawn before and after infusion. vWF:Ag increased promptly. No pro-vWF could be detected when the first postinfusion sample was drawn after 30 minutes (pigs) or 60 minutes (mice), but pro-vWF was detectable for short periods when postinfusion samples were drawn after 15 minutes (dog) or 5 minutes (baboons). In contrast, free propeptide was increased at the first timepoint measured, suggesting that it was generated from the pro-vWF in the rpvWF preparation. vWF multimers were analyzed in the rpvWF preparation and in plasma samples drawn before and after infusion of rpvWF using ultra-high resolution 3% agarose gels to allow separation of homo- and hetero-forms of the vWF polymers. Within 30 minutes after infusion in the pigs, 1 hour in the dog and the mice, and within 2 hours in the baboons, the multimer pattern had changed to that typically seen in mature vWF. These data indicate that propeptide cleavage from unprocessed vWF can occur extracellularly in the circulation. The enzyme or enzymes responsible for this cleavage in plasma remain to be identified.

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Capsaicin effects on blinking

Arquivos de Neuro-Psiquiatria ◽

10.1590/s0004-282x2005000500004 ◽

2005 ◽

Vol 63 (3b) ◽

pp. 745-747 ◽

Cited By ~ 3

Author(s):

Fidias E. Leon-Sarmiento ◽

Jaime Bayona-Prieto ◽

Marta E. Leon-S

Keyword(s):

Female Subject ◽

Normal Subjects ◽

Eye Blink ◽

C Fibers ◽

Before And After ◽

Normal Human ◽

Topical Capsaicin

Blinking is a normal human phenomenom involving trigeminal and facial patways. To gain understanding on the neurobiology of blinking, five normal subjects were investigated before and after application of transdermal capsaicin at the forehead for two weeks. No effects of topical capsaicin were detected in eye blink rates. However, when capsaicin was applied to a female subject with blepharospasm, she showed a dramatic restoration of her vision subsequent to blinking modification. Deactivation of abnormal A-to-C fibers cross talks at the trigeminal-facial pathways seems to be the most likely mechanism of such improvement.

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