Properties of SiO2 Films Fabricated by Microwave ECR Plasma Processing with and without Energetic Particle Bombardment During Film Deposition. Part II: Electronic Properties

1991 ◽  
Vol 225 ◽  
Author(s):  
T. T Chau ◽  
S. R. Mejia ◽  
K. C. Kao
Keyword(s):  
Electronic Properties ◽  
Particle Bombardment ◽  
Energetic Particle ◽  
Plasma Processing ◽  
Film Deposition ◽  
Dust Particles ◽  
Phase Reaction ◽  
Ecr Plasma ◽  
Group A ◽  
Group B

ABSTRACTSilicon dioxide (SiO2) films were fabricated by microwave ECR plasma processing at 300°C, the range of the film thicknesses being 200 - 300 Å. Two groups of films were fabricated; group A with the substrates placed in a position directly facing the plasma so that the substrates as well as the on-growing films were subjected to bombardment of energetic particles produced in the plasma, and group B with the substrates placed in a processing chamber physically separated from the plasma chamber in order to prevent or suppress the damaging effects resulting from these energetic particle bombardment. It has been found that group A films are poor in both the capacitance-voltage (C-V) and the current-voltage (I-V) characteristics, possibly due to dust particles created by the gas phase reaction of SiH4 and ionic bombardment and radiation damage during film deposition. Group B films, on the other hands, exhibit good electronic properties. On the basis of their I-V and C-V characteristics, group B films yield an average breakdown strength of about 10 MV/cm, an oxide bulk charge density on the order of 1014 q/cm3 and an interface trap density on the order of 1011 cm−2 eV−1 which are approaching those of high quality thermally grown oxides and they are suitable for use as gate insulator for MOS devices.

Properties of SiO2 Films Fabricated by Microwave Ecr Plasma Processing with and Without Energetic Particle Bombardment During Film Deposition Part I. Fabrication Processes and Physical Properties

1991 ◽  
Vol 223 ◽  
Author(s):  
T. T. Chau ◽  
S. R. Mejia ◽  
K. C. Kao
Keyword(s):  
Silicon Dioxide ◽  
Particle Bombardment ◽  
Energetic Particle ◽  
Deposition Temperature ◽  
Film Growth ◽  
Plasma Processing ◽  
Film Deposition ◽  
Ecr Plasma ◽  
Group A ◽  
Group B

ABSTRACTSilicon dioxide (SiO2) films were fabricated by microwave ECR plasma processing. Two groups of films were fabricated; group A with the substrates placed in a position directly facing the plasma so that the substrates as well as the on-growing films were subjected to bombardment of energetic particles produced in the plasma, and group B with the substrates placed in a processing chamber physically separated from the plasma chamber in order to prevent or suppress the damaging effects resulting from these energetic particle bombardment. The systems used for fabricating these two different groups of samples are described. The films were deposited at various deposition temperatures. On the basis of the deposition rate as a function of deposition temperature the film growth for group A samples is due mainly to mass-limited reaction, and that for group B samples is due to surface rate limited reaction. The stoichiometric level for group A does not change with deposition temperature though the films density increases with increasing deposition temperature. However, group B samples exhibit an off-stoichiometric property but they become highly stoichiometric as the deposition temperature is increased beyond 200 °C

Ion-Beam-Assisted Deposition and Synthesis

MRS Bulletin ◽  
1987 ◽  
Vol 12 (2) ◽  
pp. 40-51 ◽  
Author(s):  
S.M. Rossnagel ◽  
J.J. Cuomo
Keyword(s):  
Thin Film ◽  
Particle Bombardment ◽  
Energetic Particle ◽  
Ion Beam ◽  
Chemical Properties ◽  
Film Surface ◽  
Arrival Rate ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Deposition Techniques

Concurrent energetic particle bombardment during film deposition can strongly modify the structural and chemical properties of the resulting thin film. The interest in this technique, ion-assisted deposition, comes about because it can be used to produce thin films with properties not achievable by conventional deposition. Bombardment by low energy ions occurs during almost all plasma-based thin film deposition techniques. Bombardment of a growing film, particularly by accelerated ions, can also be combined with non-plasma-based deposition techniques, such as evaporation, to simulate some of the effects observed with sputtering. The bombarding particle flux is usually controllable so that the arrival rate, energy, and species can be independently varied from the depositing flux. Thus, a basic aspect of ion-beam-based deposition techniques is the “control” often absent in plasma-based techniques. In plasmas, the voltage, current, and pressure are all interdependent. The energetic bombardment at the substrate-film interface depends on the various properties of the plasma, as does the deposition rate. It is often difficult, or even impossible, to decouple these processes. With ion-beam-based deposition techniques, the ion bombardment is essentially independent of the deposition process, and both can be more easily controlled.The incident energetic particle contributes some of its energy or momentum to irreversibly change the dynamics of the film surface. The incident particle may also be incorporated into the growing film, changing the film's chemical nature. The changes induced by particle bombardment during deposition are often not characteristic of equilibrium thermodynamics because the incident particle's energy is often many times the local adsorption or binding energy.

An ultrastructural study of sertoli cells in two geographically isolated populations of Aphanius dispar

1992 ◽  
Vol 50 (1) ◽  
pp. 548-549
Author(s):  
Taber A. Ba-Omar ◽  
Philip F. Prentis
Keyword(s):  
Ultrastructural Level ◽  
Uranyl Acetate ◽  
Freshwater Teleost ◽  
Isolated Populations ◽  
En Bloc ◽  
The North ◽  
Group A ◽  
Ultrathin Sections ◽  
Group B ◽  
Geographically Isolated

We have recently carried out a study of spermiogenic differentiation in two geographically isolated populations of Aphanius dispar (freshwater teleost), with a view to ascertaining variation at the ultrastructural level. The sampling areas were the Jebel Al Akhdar in the north (Group A) and the Dhofar region (Group B) in the south. Specimens from each group were collected, the testes removed, fixed in Karnovsky solution, post fixed in OsO, en bloc stained with uranyl acetate and then routinely processed to Agar 100 resin, semi and ultrathin sections were prepared for study.

Comparison of one-year prognosis of patients classified as chronic critical lower limb ischaemia according to TASC II or European consensus definition in the COPART cohort

VASA ◽  
2015 ◽  
Vol 44 (3) ◽  
pp. 0220-0228 ◽  
Author(s):  
Marion Vircoulon ◽  
Carine Boulon ◽  
Ileana Desormais ◽  
Philippe Lacroix ◽  
Victor Aboyans ◽  
...  
Keyword(s):  
Medical Treatment ◽  
Critical Limb Ischaemia ◽  
Limb Ischaemia ◽  
Medical Group ◽  
Consensus Definition ◽  
Transcutaneous Oxygen ◽  
European Consensus ◽  
Group A ◽  
One Year ◽  
Group B

Background: We compared one-year amputation and survival rates in patients fulfilling 1991 European consensus critical limb ischaemia (CLI) definition to those clas, sified as CLI by TASC II but not European consensus (EC) definition. Patients and methods: Patients were selected from the COPART cohort of hospitalized patients with peripheral occlusive arterial disease suffering from lower extremity rest pain or ulcer and who completed one-year follow-up. Ankle and toe systolic pressures and transcutaneous oxygen pressure were measured. The patients were classified into two groups: those who could benefit from revascularization and those who could not (medical group). Within these groups, patients were separated into those who had CLI according to the European consensus definition (EC + TASC II: group A if revascularization, group C if medical treatment) and those who had no CLI by the European definition but who had CLI according to the TASC II definition (TASC: group B if revascularization and D if medical treatment). Results: 471 patients were included in the study (236 in the surgical group, 235 in the medical group). There was no difference according to the CLI definition for survival or cardiovascular event-free survival. However, major amputations were more frequent in group A than in group B (25 vs 12 %, p = 0.046) and in group C than in group D (38 vs 20 %, p = 0.004). Conclusions: Major amputation is twice as frequent in patients with CLI according to the historical European consensus definition than in those classified to the TASC II definition but not the EC. Caution is required when comparing results of recent series to historical controls. The TASC II definition of CLI is too wide to compare patients from clinical trials so we suggest separating these patients into two different stages: permanent (TASC II but not EC definition) and critical ischaemia (TASC II and EC definition).

Absorbable suture material in carotid surgery

VASA ◽  
2015 ◽  
Vol 44 (6) ◽  
pp. 451-457 ◽  
Author(s):  
Vincenzo Gasbarro ◽  
Luca Traina ◽  
Francesco Mascoli ◽  
Vincenzo Coscia ◽  
Gianluca Buffone ◽  
...  
Keyword(s):  
Suture Material ◽  
Absorbable Suture ◽  
Paediatric Surgery ◽  
Carotid Surgery ◽  
Suture Materials ◽  
Absorbable Suture Material ◽  
Absorbable Sutures ◽  
Group A ◽  
Group B

Abstract. Background: Absorbable sutures are not generally accepted by most vascular surgeons for the fear of breakage of the suture line and the risk of aneurysmal formation, except in cases of paediatric surgery or in case of infections. Aim of this study is to provide evidence of safety and efficacy of the use of absorbable suture materials in carotid surgery. Patients and methods: In an 11 year period, 1126 patients (659 male [58.5 %], 467 female [41.5 %], median age 72) underwent carotid endarterectomy for carotid stenosis by either conventional with primary closure (cCEA) or eversion (eCEA) techniques. Patients were randomised into two groups according to the type of suture material used. In Group A, absorbable suture material (polyglycolic acid) was used and in Group B non-absorbable suture material (polypropylene) was used. Primary end-point was to compare severe restenosis and aneurysmal formation rates between the two groups of patients. For statistical analysis only cases with a minimum period of follow-up of 12 months were considered. Results: A total of 868 surgical procedures were considered for data analysis. Median follow-up was 6 years (range 1-10 years). The rate of postoperative complications was better for group A for both cCEA and eCEA procedures: 3.5 % and 2.0 % for group A, respectively, and 11.8 % and 12.9 % for group B, respectively. Conclusions: In carotid surgery, the use of absorbable suture material seems to be safe and effective and with a general lower complications rate compared to the use of non-absorbable materials.

Randomized trial of medical compression stockings versus two-layer short-stretch bandaging in the management of venous leg ulcers

Phlebologie ◽  
2009 ◽  
Vol 38 (04) ◽  
pp. 157-163 ◽  
Author(s):  
A. Franek ◽  
L. Brzezinska-Wcislo ◽  
E. Blaszczak ◽  
A. Polak ◽  
J. Taradaj
Keyword(s):  
Drug Therapy ◽  
Randomized Clinical Trials ◽  
Therapy Group ◽  
Long Term Results ◽  
Leg Ulcers ◽  
Compression Stockings ◽  
Venous Leg Ulcers ◽  
Group A ◽  
Group B ◽  
Medical Compression Stockings

SummaryA prospective randomized clinical trial was undertaken to compare a medical compression stockings with two-layer short-stretch bandaging in the management of venous leg ulcers. Study endpoints were number of completely healed wounds and the clinical parameters predicting the outcome. Patients, methods: Eighty patients with venous leg ulcers were included in this study, and ultimately allocated into two comparative groups. Group A consisted of 40 patients (25 women, 15 men). They were treated with the compression stockings (25–32 mmHg) and drug therapy. Group B consisted of 40 patients (22 women, 18 men). They were treated with the short-stretch bandages (30–40 mmHg) and drug therapy, administered identically as in group A. Results: Within two months the 15/40 (37.50%) patients in group A and 5/40 (12.50%) in group B were healed completely (p = 0.01). For patients with isolated superficial reflux, the healing rates at two months were 45.45% (10/22 healed) in group A and 18.18% (4/22 healed) in group B (p = 0.01). For patients with superficial plus deep reflux, the healing rates were 27.77% (5/18 healed) in group A and 5.55% (1/18 healed) in group B (p = 0.002). Comparison of relative change of the total surface area (61.55% in group A vs. 23.66% in group B), length (41.67% in group A vs. 27.99% in group B), width (46.16% in group A vs. 29.33% in group B), and volume (82.03% in group A vs. 40.01% in group B) demonstrated difference (p = 0.002 in all comparisons) in favour of group A. Conclusion: The medical compression stockings are extremely useful therapy in enhancement of venous leg ulcer healing (both for patients with superficial and for patients who had superficial plus deep reflux). Bandages are less effective (especially for patients with superficial plus deep reflux, where the efficiency compared to the stockings of applied compression appeared dramatically low). These findings require confirmation in other randomized clinical trials with long term results.

Hypercoagulable State in the Watanabe Heritable Hyperlipidemic Rabbit, an Animal Model for the Progression of Atherosclerosis

1989 ◽  
Vol 61 (01) ◽  
pp. 140-143 ◽  
Author(s):  
Yoshitaka Mori ◽  
Hideo Wada ◽  
Yutaka Nagano ◽  
Katsumi Deguch ◽  
Toru Kita ◽  
...  
Keyword(s):  
Vitamin K ◽  
Fibrinogen Level ◽  
Plasma Cholesterol ◽  
Age Groups ◽  
Clotting Factor ◽  
Clotting Factors ◽  
Group A ◽  
Hyperlipidemic Rabbit ◽  
Group B ◽  
Progression Of Atherosclerosis

SummaryBlood coagulation in a strain of rabbits designated as Watanabe heritable hyperlipidemic (WHHL) rabbits was examined. The activities of vitamin K-dependent clotting factors, contact factors and clotting factor VIII (F VIII) and the fibrinogen level were significantly higher in WHHL rabbits than in normolipidemic rabbits (all age groups). Values for vitamin Independent clotting factor were already higher at 2 months of age. Contact factors and fibrinogen levels increased age after 5 to 8 months. F VIII increased between 5 and 8 months and then decreased. At 2 months of age, WHHL rabbits were divided into two groups. Group A was fed standard rabbit chow and group B standard rabbit chow containing 1% probucol. Probucol prevented the progression of atherosclerosis in group B in the absence of a significant reduction in plasma cholesterol level. F VIII and fibrinogen levels were statistically decreased in all rabbits at all ages in group B (P<0.05). These differences in clotting factors between the two groups were most obvious at 8 months (P<0.02).We conclude that vitamin K-dependent clotting factors may increase with hyperlipemia and that increases in F VIII and fibrinogen may be closely related to the progression of throm- boatherosclerosis.

Factor II Related Antigen and Antithrombin III Levels as Indicators of Liver Failure in Consumption Coagulopathy

1982 ◽  
Vol 47 (03) ◽  
pp. 218-220 ◽  
Author(s):  
P Sié ◽  
E Letrenne ◽  
C Caranobe ◽  
M Genestal ◽  
B Cathala ◽  
...  
Keyword(s):  
Liver Failure ◽  
Antithrombin Iii ◽  
Coagulation Factors ◽  
Consumption Coagulopathy ◽  
Blood Coagulation Factors ◽  
Factor Ii ◽  
At Iii ◽  
Group A ◽  
Group B

SummaryIn order to detect impaired synthesis of blood coagulation factors associated to consumption coagulopathy, a simultaneous evaluation of factor II-related antigen (II rAg) and of antithrombin III (AT III) was carried out in 16 patients affected with severe defibrination. An in vitro preliminary study on plasma and serum demonstrated that the levels of II rAg and of AT III, assessed by the Laurell technique with Behring antisera, were not reduced by the coagulation process. The patients were, a posteriori, classified into two groups according to the absence (group A) or the presence (group B) of factors predisposing to liver failure such as metastasis, cirrhosis, and prolonged shock. II rAg and AT III levels are significantly correlated; they are in the normal range in group A but reduced in group B. Thus II rAg or AT III level determinations are useful markers in the detection of liver failure associated to the consumption phenomenon. These results also suggest that part of the decreased AT III levels reported in severe cases of disseminated intravascular coagulation may be the consequence of an associated liver failure.

Blood Viscosity and Platelet Aggregation in Male and Female Patients with Transient Ischaemic Attacks (TIA)

1979 ◽  
Author(s):  
G. Palareti ◽  
M. Poggi ◽  
G. Fortunato ◽  
S. Coccheri
Keyword(s):  
Platelet Aggregation ◽  
Blood Viscosity ◽  
Indirect Evidence ◽  
Vascular Lesions ◽  
Transient Ischaemic Attacks ◽  
Group A ◽  
Circulating Platelet Aggregates ◽  
Male Patients ◽  
Group B ◽  
Almost All

A series of 40 patients with TIA (25 males and 15 females) was thoroughly investigated by means of angiography and computerized tomography, and divided into a group (A) of 15 “sine materia”, and a group (B) of 25 with direct or indirect evidence of vascular occlusive or stenotic changes. Blood viscosity at 230 sec-1 37° was cp 4.2 ± 0.3 in the controls, cp 4.7 ± 0.7 in all patients (p < 0.05) cp 4.98 ± 0.7 in all male patients (p < 0.01 versus male controls), and cp 4.75 ± 0.8 in group B (p < 0.02). Haematocrit and Fibrinogen were also significantly increased in all male patients and in group B. Circulating platelet aggregates (CPA) were increased in 40% of the patients. Almost all patients with elevated CPA were males, with a slight prevalence in group B. Changes in blood viscosity parameters and in platelet aggregation in TIA patients were therefore related both to evidence of vascular lesions, and to sex, since they were found to prevail in male patients of both groups.

Study the Relationship Between Estrogen Hormone and Calcium in Normal Females Before and After Menopause in Baghdad / Iraq

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Sameerah Mustafa ◽  
Asal Tawfeeq ◽  
Hadeel Hasan
Keyword(s):  
Oral Contraceptive ◽  
Healthy Controls ◽  
Serum Samples ◽  
Oral Contraceptive Pills ◽  
Contraceptive Pills ◽  
Menopausal Women ◽  
Before And After ◽  
Group A ◽  
Group B ◽  
Age Range

This study involved the collection of (90) samples of women serum which included (30) serum samples collected from women before menopause (reproductive women) in the age range of (22-43) years and were considered as (group A- control). While, (group B) included (30) serum samples collected from women using oral contraceptive pills between the ages of (22-43) years old. Whereas, another (30) serum samples were collected from women after menopause between the ages of (43-54) years and were considered as (group C). All of the collected serum samples were subjected to a number of serological and chemical tests for the measurement of (E2, HDL, LDL and Ca). Then, the obtained data were statistical analyzed and results showed a significant decrease (p˂ 0.05) in (E2 ,Ca and HDL) levels in menopausal women compared to that of the normal healthy controls. While, there were non-significant decrease (p> 0.05) in (E2, Ca and HDL) levels in women taking oral contraceptive when compared to the normal healthy controls. On the other hand, a significant increase (p˂ 0.05) was recorded in LDL level in menopausal women compared to that of the normal healthy controls whereas, no-significant increase (p˃ 0.05) in the LDL level in women taking oral contraceptives when compared to the control women.

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