Dopants in Hgcdte

1997 ◽  
Vol 487 ◽  
Author(s):  
M. A. Berding ◽  
A. Sher

AbstractIn this paper we discuss our ab initio calculations of native point defect and impurity densities in HgCdTe. Our calculations have explained the experimental finding in general, and in particular have explained the in-active incorporation of the group VII elements under mercury-deficient conditions; have shown that the group I elements have a large fraction of interstitial incorporation, thereby explaining their fast diffusion; and have described a microscopic mechanism for the amphoteric behavior of the group V elements. We discuss the trends found among the compounds in terms of the underlying bond strengths to understand why the various elements behave the way they do.

1997 ◽  
Vol 484 ◽  
Author(s):  
M. A. Berding ◽  
A. Sher

AbstractIn this paper we discuss our ab initio calculations of native point defect and impurity densities in HgCdTe. Our calculations have explained the experimental finding in general, and in particular have explained the in-active incorporation of the group VII elements under mercury-deficient conditions; have shown that the group I elements have a large fraction of interstitial incorporation, thereby explaining their fast diffusion; and have described a microscopic mechanism for the amphoteric behavior of the group V elements. We discuss the trends found among the compounds in terms of the underlying bond strengths to understand why the various elements behave the way they do.


Author(s):  
Anton Bózner ◽  
Mikuláš Gažo ◽  
Jozef Dostál

It is anticipated that Japanese quail /Coturnix coturnix japonica/ will provide animal proteins in long term space flights. Consequently this species of birds is of research interest of international space program INTERCOSMOS. In the year 1987 we reported on an experiment /2/ in which the effect of chronic acceleration of 2 G hypergravitation, the hypodynamy and the simultaneous effect of chronic acceleration and the location in the centre of the turntable of the centrifuge on the protein fractions in skeletal muscles was studied. The ultrastructure of the heart muscle was now in this experiments examined as well.Japanese quail cockerels, aged 48 days were exposed to 2 G hypergravitation /group IV/ in a 6,4 m diameter centrifuge, to hypodynamy /group III/ and their combination /group V/, respectively for 6 days / Fig.1/. The hypodynamy in group III was achieved by suspending the birds in jackets without contact the floor. The group II was located in the centre ofthe turntable of the centrifuge. The control group I. was kept under normal conditions. The quantitative ultrastructure of myocard was evaluated by the methods of Weibel/3/ - this enables to determine the number, relative size and volume of mitochondria volume of single mitochondria, defficiency of mitochondrial cristae and volume of myofibrils.


Author(s):  
A. I. Shah ◽  
D. M. Patel ◽  
N. P. Sarvaiya ◽  
S. P. Madhira

This study was undertaken on 36 freshly calved cows randomly divided into 6 equal groups under field conditions. Cows of group-VI that shed placenta within 8-12 hours postpartum naturally served as healthy control. The cows with retained fetal membranes (RFM, n = 18) for more than 12 hrs were managed either by manual removal of placenta without antibiotics (group-I), parenteral antibiotic (Ceftiofur 1 g i/m) for three consecutive days (group-II) or a combination of both (group-III). In group-IV and group-V, cows were administered with Inj. Oxytocin @ 50 IU i/m and Inj. Dinoprost tromethamine (PGF2α) @ 25 mg i/m, respectively, immediately after parturition and time of placental shedding was recorded. The overall prevalence of Brucellosis by RBPT was found to be 5.55 % amongst these 36 animals. The placental expulsion in groups following medicinal treatment was found to be 50 (3/6) % in Ceftiofur alone by 3 days (group-II), and 66.67 (4/6) % in Oxytocin (group-IV) and 100 (6/6) % in PGF2α inj. (group-V) groups within 12 hrs. The time of uterine involution in groups I to VI was found to be 42.00 ± 1.94, 39.50 ± 0.99, 40.67 ± 1.39, 38.33 ± 1.55, 37.50 ± 1.02 and 37.33 ± 1.76 days, respectively, while the interval for the appearance of first postpartum estrus was 54.83 ± 2.06, 51.00 ± 1.05, 52.17 ± 1.96, 50.17 ± 2.03, 48.67 ± 1.90 and 49.17 ± 1.55 days, respectively, which did not vary statistically. The mean serum progesterone profile obtained on day 0 and day 21 postpartum was statistically non-significant between groups. However, it was significantly (p less than 0.05) lower on day 0 as compared to day 21 in group-I, II and VI. The levels on day 0 coincided with the time of blood sampling after calving. The high level of serum P4 on day 0 in group-IV and V could be due to sampling immediately after calving. The serum calcium and phosphorus levels were significantly(p less than 0.05) lower on day 0 than on day 21, but not the magnesium. The group effect was however non-significant for any of three minerals. It was observed that manual removal of RFM without parenteral antibiotics, resulted in puerperal metritis, cervicitis, pyometra which ultimately resulted into delayed uterine involution, delayed first postpartum estrus and thus, reduced the postpartum reproductive efficiency. It was inferred that the PGF2α and Oxytocin injections could be used as a treatment of choice for prevention of RFMs in cattle.


2017 ◽  
Vol 05 (02) ◽  
pp. 084-089
Author(s):  
Alisha Dhingra ◽  
Ashu Gupta ◽  
Anshu Minocha ◽  
Nayantara Sen

Abstract Aim: The aim of this study was to compare the reversal of shear bond strength of composite to bleached enamel immediately after bleaching followed by application of various antioxidant solutions. Material and Methods: Seventy central incisors were divided into seven groups. Groups I and II served as unbleached and bleached controls respectively. Groups III, IV, V, VI and VII served as the experimental groups and were subjected to 37.5% hydrogen peroxide bleaching followed by 10 min application of 10% sodium ascorbate, 25% alpha-tocopherol, 6.5% grape seed extract, 5% lycopene and 5% green tea extract respectively. Following composite bonding, shear bond strength was determined and the results were analyzed using ANOVA followed by Post Hoc Multiple Comparisons test. Results: The bond strength values for Group I (positive control) were maximum and significantly different than all the other groups except Grape seed extract group (Group V). When compared to Group II (bleached control), all the groups showed significantly higher bond strength. Significant difference in the bond strength values were seen between Group III (10% sodium ascorbate) and Group V. Also values for Group V were significantly different from Group VI (5% lycopene). All the other values showed insignificantly different results. Conclusion: All the antioxidant solutions improved the shear bond strength values after bleaching but only Grape seed extract application reversed the values to the non bleached levels. Lycopene was least effective. Other antioxidants showed comparable results.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
S Okutucu ◽  
C Sabanoglu ◽  
A Saglam Ayhan ◽  
E Tulumen ◽  
H Aksoy ◽  
...  

Abstract Background Calcific aortic valve disease (CAVD) is the most common valvular heart disease. Bisphosphonates are stable analogs of pyrophosphates and commonly prescribed in the treatment of osteoporosis. The effects of bisphosphonate treatment on CAVD are not clearly known and there are inconsistent results. Similarly, the effect of calcium supplementation on CAVD remains controversial. Purpose The aim of this study was to assess the effects of bisphosphonate therapy on the normal aortic valve and vitamin D induced in vivo rabbit aortic stenosis (AS) model. Methods The impact of calcium supplementation on the rabbit AS model was also evaluated. A total of 30 New Zealand white rabbits were divided into five equal groups: no treatment (Group I); 25,000 IU/day vitamin D3 (cholecalciferol) (Group II, rabbit AS model); 25,000 IU/day cholecalciferol plus 2500 mg/day calcium carbonate (Group III); 20 μg/kg/week intravenous alendronate (Group IV) and 25,000 IU/day cholecalciferol plus 2500 mg/day calcium carbonate plus 20μg/kg/week alendronate (Group V). Echocardiography was performed at baseline and after 12 weeks of treatment. The left ventricular mass index (LVMI), aortic valve area (AVA), transvalvular velocities and gradients were recorded. Radiologic and histopathologic examination was performed at the end of the 12th week. Control animals displayed no abnormalities of the aortic valve. Results There was no echocardiographic change in Group IV. In Groups II, III and V, there was a significant decrease in AVA and increases in transvalvular velocities and gradients. However, these stenotic changes were significantly prominent in Group V (p=0.001 for all, via repeated measures ANOVA). Moreover, LVMI was only increased in Group V (p<0.05). Calcification of aortic valvar complex was detected in 14 (46.7%) cases by radiologic imaging and 10 (33.3%) cases by histopathologic examination. Most frequent calcification was found in Group V (5 for each method, 83.3%). Agatston, volume and equivalent mass scores of calcific foci in Group V were significantly higher than other groups (p<0.05 for all). There was no significant difference between groups regarding with presence of osteoclasts in calcific foci. Conclusion Calcium supplementation has no effect on the in vivo rabbit AS model. Alendronate treatment aggravates the stenosis and increases the calcification in the rabbit AS model. Alendronate treatment has no effect on the normal valve in which there was no osteogenesis and osteoclastogenesis. Based on these findings, in patients with CAVD, alendronate treatment should be given with regular echocardiographic follow-up or may not be preferred. Central figure Funding Acknowledgement Type of funding source: None


2006 ◽  
Vol 17 (4) ◽  
pp. 300-305 ◽  
Author(s):  
Sérgio Lima Santiago ◽  
José Carlos Pereira ◽  
Ana Christina Bonato Figueiredo Martineli

This study evaluated the influence of time after application of oxalate solutions in reducing dentin hydraulic conductance. Fifty dentin discs were obtained from extracted human third molars and assigned to 5 groups (n=10), according to the desensitizing agent used: Group I: OxaGel; Group II: experimental agent DD-1: Group III: experimental agent DD-2. In Groups IV and V, a placebo gel and deionized water were used as control, respectively. The agents were applied for 3 min, washed out and the hydraulic conductance was measured immediately and at 5-, 15- and 30-min intervals, and after acid etching. Data were analyzed statistically by two-way ANOVA and Duncan's test at 5% significance level. Groups I, II and III did not differ significantly from each other in any of the time intervals (p>0.05). Likewise, Groups IV and V were statistically similar to each other (p>0.05). The active agents reduced significantly dentin permeability in comparison to control groups (p<0.05). Dentin permeability measured in vitro decreased significantly with time regardless of the agent applied (either active or control agents). The results of Group V, in which no dentin desensitizing agent was employed, indicates that the assessment of dentin permeability by this method must be interpreted with caution.


2014 ◽  
Vol 39 (1) ◽  
pp. E9-E15 ◽  
Author(s):  
V Dhingra ◽  
S Taneja ◽  
M Kumar ◽  
M Kumari

SUMMARY This study evaluated the influence of fiber inserts, type of composites, and location of the gingival seat on microleakage in Class II resin composite restorations. Fifty noncarious human third molars were selected for the study. Standardized Class II box type cavities were prepared on the mesial and distal side of 45 teeth. The gingival margin was placed above the cementoenamel junction (CEJ) on the mesial side and below the CEJ on the distal side. The remaining five teeth received no cavity preparations. The prepared samples were divided randomly on the basis of type of composite and presence or absence of fiber inserts, into four experimental groups of 10 teeth each and two control groups of five teeth each. The groups were defined as follows: group I (n=10) – Z350 XT; group II (n=10) – Z350 XT with fibers; group III (n=10) – P90; group IV (n=10) – P90 with fibers; and group V (n=5) – positive controls, cavities were not restored; group VI (n=5) – negative controls, no cavities were prepared. The samples were stored in distilled water in incubator at 37°C for 24 hours and then subjected to 500 cycles of thermocycling (5°C and 55°C) with a dwell time of 15 seconds. They were then placed in a 2% methylene blue dye solution for 24 hours at 37°C. Samples were sectioned longitudinally and evaluated for microleakage at the occlusal and gingival margin under a stereomicroscope at 20× magnification. Kruskal-Wallis and Mann-Whitney U-tests were used to compare the mean leakage scores. Restorations with gingival margins in enamel showed significantly less microleakage. Significant reduction in microleakage was observed in groups restored with P90 composite than those restored with Z350 XT. No improvement in microleakage was observed with the use of fiber inserts (p&gt;0.05).


2021 ◽  
pp. 39-45
Author(s):  
Nura I. Al-Zail ◽  
Salah F. Kamies

Pyrethroid cyhalothrin (PC) is an insecticide that is used worldwide for pest control in agriculture and household use. Samoa extract (SE) is a potent antioxidant protecting cells from oxidative stress. The present study investigates the protective and therapeutic effect of SE on PC-induced changes in sperm quality in male rats. Fifty adult male albino rats were divided into five groups: group I: served as control; group II: received PC i.p. only (6.2 mg/kg b.wt.); group III: received SE only (100 mg/kg b.wt., p.o.) for eight weeks; group IV: received SE as a protective agent daily for eight weeks, then followed by the administration of PC (i.p.) three times a week for two weeks; group V: exposed to PC (i.p.) three times a week for two weeks, then treated with the SE daily for 8 weeks. Results showed that PC caused markedly impaired sperm quality (a count, viability, motility, and abnormality). Compared to PC-treated animals, SE in the protective group markedly restored the alteration of sperm indices. However, SE in the curative group was found to be less effective in restoring PC-induced alterations. In conclusion, the data of this study revealed that the SE as a protective agent is more effective than as a therapeutic agent. Keywords: Samoa; Pyrethroid; Sperm quality; Rat


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