Mean Lifetime of an Embryo in the Homogeneous Nucleation from Solution of the Tetracyanoplatinates(II) of Barium, Calcium, and Magnesium

1973 ◽  
Vol 51 (20) ◽  
pp. 3435-3442 ◽  
Author(s):  
O. A. Bempah ◽  
O. E. Hileman Jr.
Keyword(s):  
Homogeneous Nucleation ◽  
Silicone Oil ◽  
Classical Model ◽  
Selective Extraction ◽  
Supersaturation Ratio ◽  
Mean Lifetime ◽  
High Supersaturation ◽  
The Mean ◽  
Calcium And Magnesium ◽  
Oil Crystallization

The mean lifetime of an embryo in the homogeneous nucleation from aqueous solution of the tetracyanoplatinates(II) of barium, calcium, and magnesium has been studied using the droplet technique. Supersaturation in the droplets was generated by selective extraction of the solvent into the surrounding silicone oil. Crystallization in the droplets was followed by photomicrography using plane polarized light.The data were analyzed using both the classical model and the mean lifetime model of Carlier and Frisch. The experimental results are consistent with the predicted relationship between the logarithm of the nucleation rate or the logarithm of the mean lifetime of an embryo and the inverse of the square of the logarithm of the supersaturation ratio at high supersaturation ratios. The calculated values of the inter-facial energy, using both models, are in close enough agreement to justify the assumptions made in the analysis.

Temperature Dependences in the O + OH → O2 + H Reaction. Quasiclassical Trajectory Calculation

1993 ◽  
Vol 58 (2) ◽  
pp. 234-243 ◽  
Author(s):  
Viliam Klimo ◽  
Martina Bittererová ◽  
Stanislav Biskupič ◽  
Ján Urban ◽  
Miroslav Micov
Keyword(s):  
Temperature Dependence ◽  
Energy Surface ◽  
Analytical Form ◽  
Mean Values ◽  
Quantum Numbers ◽  
Mean Lifetime ◽  
Temperature Dependences ◽  
Quasiclassical Trajectory Calculation ◽  
The Mean ◽  
Combustion Processes

The reaction O + OH → O2 + H in conditions of combustion of hydrocarbons and polymers was modelled by using the method of quasiclassical trajectories. The potential energy surface was determined by the multiconfiguration interaction method and fitted with the analytical form of the extended LEPS function. Attention was paid to the mean values of the vibrational and rotational quantum numbers of O2 molecules and their temperature dependence. The temperature dependence of the mean lifetime of the OOH collision complex was also examined. The calculated rate constants were analyzed and compared with the experimental data over the temperature region of the combustion processes.

Retinotomy and retinectomy for anterior inferior proliferative vitreoretinopathy: Can visual outcome be improved?

2021 ◽  
pp. 112067212110128
Author(s):  
Mumin Hocaoglu ◽  
Murat Karacorlu ◽  
M. Giray Ersoz ◽  
Isil Sayman Muslubas ◽  
Serra Arf
Keyword(s):  
Proliferative Vitreoretinopathy ◽  
Rhegmatogenous Retinal Detachment ◽  
Silicone Oil ◽  
Clinical Stage ◽  
Case Series ◽  
Visual Outcome ◽  
Attachment Rate ◽  
Good Visual Outcome ◽  
The Mean

Purpose: To describe the treatment outcomes and prognostic factors of retinotomy/retinectomy for rhegmatogenous retinal detachment (RD) complicated anterior inferior proliferative vitreoretinopathy (PVR). Methods: Retrospective, nonrandomized, single-center case series. The outcomes of 126 cases of retinotomy/retinectomy for RD complicated by advanced (Grade C) anterior inferior PVR managed consistently by one surgeon during a 15-year period were evaluated. Results: Forty-two eyes (33%) had primary RDs and 84 (67%) had recurrent RDs. The extent of retinotomy/retinectomy varied: 90° in 21 eyes (17%), >90° to <180° in 49 eyes (39%), and ⩾180° to ⩽240° in 56 eyes (44%). The retinotomy/retinectomy location was peripheral in 58 eyes (46%) and equatorial in 68 eyes (54%). The mean follow-up period was 43 ± 42 months. The silicone oil (SO) was removed from 98% of the eyes. The single-operation success rate after the primary retinectomy was 87%, and the final attachment rate was 94%. Visual acuity improved from 20/630 to 20/160 ( p < 0.001). Vision ⩾20/200 was achieved in 101 eyes (80%). Good visual outcome was correlated positively with preoperative VA ( p = 0.02), previous vitrectomy with gas tamponade ( p = 0.007), and was negatively correlated with number of previous RD operations ( p = 0.01), larger extent of RD ( p = 0.02) and more extensive retinotomy/retinectomy ( p = 0.04). Conclusions: An appropriate and timely intervention, including vitrectomy alone, inferior relaxing retinotomy/retinectomy and standard SO tamponade provide satisfactory outcomes for RDs complicated by PVR. Lesser extension of grade C PVR at baseline, such as PVR limited to one quadrant should encourage vitreoretinal specialists to consider retinotomy/retinectomy at a milder clinical stage of PVR development.

Results and Complications after Implantation of a Black Iris-Lens Diaphragm in Patients with Traumatically Induced Aphakia and Aniridia

2011 ◽  
Vol 21 (6) ◽  
pp. 754-759 ◽  
Author(s):  
Vasileios Petousis ◽  
Lothar Krause ◽  
Gregor Willerding ◽  
Michael H. Foerster ◽  
Nikolaos E. Bechrakis
Keyword(s):  
Anterior Chamber ◽  
Surgical Repair ◽  
Silicone Oil ◽  
Case Series ◽  
Corrected Visual Acuity ◽  
Time Out ◽  
Anatomic Results ◽  
The Mean ◽  
Positive Effect

Purpose. The black iris-lens diaphragm (ILD) can be used in the treatment of traumatic aniridia and aphakia. The aim of our study was to show postoperative functional and anatomic results and complications in a small case series. Methods. We retrospectively analyzed the files of 16 patients managed with a black ILD or a sole iris diaphragm in the period 1994–2007. Four of them were female and 12 were male. The mean age of the group was 50±17 years. At the time of the implantation, all of the eyes had already undergone primary surgical repair. Results. The preoperative best-corrected visual acuity in half of the patients was ≥0.1 and remained stable after the first postoperative year. During the follow-up years, one eye developed a subluxation of the implant and one eye an anterior chamber hemorrhage. At the same time, out of 8 eyes carrying a silicone tamponade in the vitreous cavity, silicone oil entered the anterior chamber in 3 cases. In one case, enucleation was undertaken due to phthisis. Conclusions. In the case of severely traumatized eyes with aniridia and aphakia, the implantation of a black ILD can have a positive effect on functional and anatomic stabilization.

scholarly journals On the Absoluteness of Time

2017 ◽  
Vol 9 (3) ◽  
pp. 46
Author(s):  
Carmine Cataldo
Keyword(s):  
Analytical Solutions ◽  
Relativistic Corrections ◽  
Mean Lifetime ◽  
The Mean

This paper aims to qualitatively summarize the results up until now obtained in investigating the compatibility between the absoluteness of time and several well-known phenomena, such as the alleged increase of the mean lifetime of muons and the so-called relativistic corrections for GPS, whose explanation is commonly provided by resorting to Einstein’s Relativity. To make the discussion more flowing, we have herein preferred to completely avoid the writing of equations. All the analytical solutions, as well as several explicative figures, can be found in the first six articles cited in the references, drafted by the same author of this manuscript.

A Formula for the Mean Lifetime of Metapopulations in Heterogeneous Landscapes

2002 ◽  
Vol 159 (5) ◽  
pp. 530-552 ◽  
Author(s):  
Karin Frank ◽  
Christian Wissel
Keyword(s):  
Heterogeneous Landscapes ◽  
Mean Lifetime ◽  
The Mean

High Temperature Laminate Characterization

2014 ◽  
Vol 2014 (HITEC) ◽  
pp. 000235-000245
Author(s):  
David Shaddock ◽  
Liang Yin
Keyword(s):  
Weight Loss ◽  
High Temperature ◽  
Printed Circuit Boards ◽  
Stress Test ◽  
Model Development ◽  
Peel Strength ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Mean Lifetime ◽  
The Mean

Printed circuit boards have been reported to have limited lifetime at 200 to 250°C. Characterization and modeling high temperature laminates for application at 200 to 250°C was conducted to better quantify the mean lifetime using accelerated testing of key functional parameters. Life testing and model development was applied for via cyclic life, peel strength, and weight loss. Four high temperature laminates consisting of 2 types were evaluated. Via lifetime was characterization using Interconnect Stress Test (IST) coupons. Peel strength was tested using IPC IPC-TM-650 method 2.4.8c. Weight loss was characterized using isothermal aging. Comparison of lifetime is made between the laminate samples.

Endoscopy-Assisted Vitrectomy Outcomes During Silicone Oil Removal After Complex Retinal Detachment Repair

2019 ◽  
Vol 3 (6) ◽  
pp. 445-451 ◽  
Author(s):  
Natalia Vila ◽  
Emmanouil Rampakakis ◽  
Flavio Rezende
Keyword(s):  
Retrospective Study ◽  
Retinal Detachment ◽  
Pars Plana Vitrectomy ◽  
Silicone Oil ◽  
Endoscopic Examination ◽  
Oil Removal ◽  
Visualization System ◽  
Silicone Oil Removal ◽  
Pars Plana ◽  
The Mean

Purpose: This retrospective study recorded intraoperative findings during silicone oil removal and postoperative anatomical outcomes comparing endoscopy-assisted pars plana vitrectomy (E-PPV) vs pars plana vitrectomy (PPV) alone after proliferative vitreoretinopathy (PVR)-related retinal detachment (RD) repair. Methods: This single-center retrospective study included patients who underwent PPV for silicone oil removal after RD with PVR from July 2009 to January 2017. Patients with diabetic tractional RD, history of trauma, uveitis, or endophthalmitis were excluded. After 2013, an endoscopic visualization system (E2 MicroProbe; Endo Optiks) was used in a nonrandomized fashion. Data collection included reattachment rate, intraoperative endoscopic findings and phthisis rate. Results: Fifty-four eyes of 54 patients were included. The mean participant age was 58.4 ± 12.9 years and 36 (65.5%) participants were male. The mean (± SD) follow-up duration after oil removal was 24.3 ± 20.1 months. E-PPV combined with wide-angle visualization system was performed in 26 (48.1%) of the patients; the surgical management was modified after endoscopic examination in 17 (65.4%) of the cases. Reattachment rate in the E-PPV group was 96.2% compared with 76.0% in the PPV-alone group ( P = .04). Conclusions: E-PPV for silicone oil removal appears to be advantageous for prevention of RD recurrence, thus achieving better reattachment rates. A thorough examination is facilitated by endoscopic visualization and contributory factors for anterior PVR can be identified and treated.

The post-synaptic action of some putative excitatory transmitter substances

1976 ◽  
Vol 192 (1109) ◽  
pp. 481-489 ◽  
Keyword(s):  
Current Fluctuations ◽  
Synaptic Action ◽  
Synaptic Noise ◽  
Mean Lifetime ◽  
The Mean ◽  
Excitatory Transmitter

L-Glutamate, L-aspartate and L-cysteate all produce current fluctuations when applied to the excitatory junctional membrane of Maia squinado . This post-synaptic ‘noise’ indicates that all three substances cause an elementary conductance event of approximately the same amplitude but with different average lifetimes. The mean lifetime of the ‘molecular shot effect’ produced by L-aspartate and L-cysteate is only about half that of L-glutamate.

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