430 research outputs found

    Role of interface charges on high-k based poly-Si and aetal gate nano-scale MOSFETs

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    The characteristics of typical sub-100 nm high K gate dielectrics MOSFET with different gate materials are simulated by two dimensional device simulators (ATLAS and ATHENA). The impact of interface charges on the characteristics of Poly-Si and TiN metal gate MOSFETs are investigated. The simulation results shows that, at high interface charge densities, the devices with Poly-Si gate degrade much compared to metal gate MOSFET structures. Emphasis is given to study the mobility degradation which stands as a major hurdle with the implementation of high-k dielectrics in nano-scale devices. The advantages of using Watt model over other models for the extraction of channel mobility is also clearly explained. The performance of the high-k MOSFET with metal electrode and poly-silicon electrode is also compared for various interface state charges. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2788

    Vascularity of human atrioventricular valves: A myth or fact?

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    BackgroundKnowledge of heart valve vascularity is an important factor for understanding the valvular pathology and to develop tissue-engineered valves for repair procedures. Some investigators believe that blood vessels may exist in normal human heart valves whereas some recent publications have proposed that the presence of blood vessels in the valves is secondary to inflammation.MethodsTissues from 60 normal formalin-fixed human hearts were examined microscopically for type, location, and number of vessels in atrioventricular valves. The age of the patient ranged from 10 to 70 years, and an attempt was made to study the age-related morphologic changes in atrioventricular valves.ResultsOf the 60 tricuspid and 60 mitral valves examined, 12 tricuspid (20%) and 14 mitral (23.33%) valves were found to have vessels without the presence of an inflammatory process. In tricuspid valves the vessels were observed mainly in the fibrosa layer with a range of 1 to 4 vessels, whereas in mitral valves the vessels were situated mainly in the spongiosa layer with a range of 1 to 2 vessels. The maximum vascularity was seen in the fourth decade of life, in which the vessels were found in 40% of both tricuspid and mitral valves. The mean transverse diameter of these vessels was 0.23 ± 0.18 mm, with a range of 0.06 to 0.79 mm in tricuspid valves, whereas it was 0.15 ± 0.08 mm, with a range of 0.04 to 0.4 mm in mitral valves. The capillaries (3-11 capillaries) were found scattered in the fibrosa and spongiosa with an average lumen area of 0.39 ± 0.18 mm2.ConclusionsThe blood vessels in atrioventricular valves also can be seen in the absence of inflammation and are likely to be a necessary component of valve leaflets. Thus, when performing procedures involving in situ tissue engineering and valve repair the physician needs to be aware of the presence of these vessels in human heart valves

    Quantifying uncertainty in the measurement of arsenic in suspended particulate matter by Atomic Absorption Spectrometry with hydride generator

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    Arsenic is the toxic element, which creates several problems in human being specially when inhaled through air. So the accurate and precise measurement of arsenic in suspended particulate matter (SPM) is of prime importance as it gives information about the level of toxicity in the environment, and preventive measures could be taken in the effective areas. Quality assurance is equally important in the measurement of arsenic in SPM samples before making any decision. The quality and reliability of the data of such volatile elements depends upon the measurement of uncertainty of each step involved from sampling to analysis. The analytical results quantifying uncertainty gives a measure of the confidence level of the concerned laboratory. So the main objective of this study was to determine arsenic content in SPM samples with uncertainty budget and to find out various potential sources of uncertainty, which affects the results. Keeping these facts, we have selected seven diverse sites of Delhi (National Capital of India) for quantification of arsenic content in SPM samples with uncertainty budget following sampling by HVS to analysis by Atomic Absorption Spectrometer-Hydride Generator (AAS-HG). In the measurement of arsenic in SPM samples so many steps are involved from sampling to final result and we have considered various potential sources of uncertainties. The calculation of uncertainty is based on ISO/IEC17025: 2005 document and EURACHEM guideline. It has been found that the final results mostly depend on the uncertainty in measurement mainly due to repeatability, final volume prepared for analysis, weighing balance and sampling by HVS. After the analysis of data of seven diverse sites of Delhi, it has been concluded that during the period from 31st Jan. 2008 to 7th Feb. 2008 the arsenic concentration varies from 1.44 ± 0.25 to 5.58 ± 0.55 ng/m3 with 95% confidence level (k = 2)

    GCM2 Silencing in Parathyroid Adenoma is associated with Promoter Hypermethylation and Gain of Methylation on Histone 3

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    PURPOSE: Glial cells missing 2 (GCM2), a zinc finger-transcription factor, is essentially required for the development of parathyroid glands. We sought to identify if the epigenetic alterations in the GCM2 transcription are involved in the pathogenesis of sporadic parathyroid adenoma. In addition, we examined the association between promoter methylation and histone modifications with disease indices. EXPERIMENTAL DESIGN: mRNA and protein expression of GCM2 were analyzed by RT-qPCR and immunohistochemistry in 33 adenomatous and 10 control parathyroid tissues. DNA methylation and histone methylation/acetylation of GCM2 promoter were measured by bisulfite sequencing and ChIP-qPCR. Additionally, we investigated the role of epigenetic modifications on GCM2 and DNA methyltransferase 1 (DNMT1) expression in PTH-C1 cells by treating with 5-aza 2\u27deoxycytidine (DAC) and BRD4770 and assessed for GCM2 mRNA and DNMT1 protein levels. RESULTS: mRNA and protein expression of GCM2 were lower in sporadic adenomatous than in control parathyroid tissues. This reduction correlated with hypermethylation (P\u3c0.001) and higher H3K9me3 levels in GCM2 promoter (P\u3c0.04) in adenomas. In PTH-C1 cells, DAC treatment resulted in increased GCM2 transcription and decreased DNMT1 protein expression, while cells treated with the BRD4770 showed reduced H3K9me3 levels but a non-significant change in GCM2 transcription. CONCLUSION: These findings suggest the concurrent association of promoter hypermethylation and higher H3K9me3 with the repression of GCM2 expression in parathyroid adenomas. Treatment with DAC restored GCM2 expression in PTH-C1 cells. Our results showed a possible epigenetic landscape in the tumorigenesis of parathyroid adenoma and also that DAC may be promising avenues of research for parathyroid adenoma therapeutics

    The Effects of Parental Attachment on Personality Traits

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    This study aims to identify parental attachment's effects on trainee counsellors' personality traits in the Universiti of Malaysia Sarawak UNIMAS. This research adopted a correlational research design. The respondents were 209 trainee counsellors from the Counselling Program, Universiti Malaysia Sarawak UNIMAS. Two questionnaires were used in this study: The Inventory of Parents and Peer Attachment (IPPA) and the Big Five Personality. The findings indicated a significant relationship between Parents Communication, Attachment and Extraversion and the Agreeableness Trait of Personality. It also showed a significant relationship between Parents Communication Attachment and Extraversion, Agreeableness and Conscientiousness. We also found a significant relationship between Parents' Alienation Attachment and Conscientiousness, Neuroticism and Openness. The study informs society about the need to increase awareness about the importance of knowing attachment styles and personality traits as both impact individuals' lives.

    The effects of parental attachment on personality traits

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    This study aims to identify parental attachment's effects on trainee counsellors' personality traits in the Universiti of Malaysia Sarawak UNIMAS. This research adopted a correlational research design. The respondents were 209 trainee counsellors from the Counselling Program, Universiti Malaysia Sarawak UNIMAS. Two questionnaires were used in this study: The Inventory of Parents and Peer Attachment (IPPA) and the Big Five Personality. The findings indicated a significant relationship between Parents Communication, Attachment and Extraversion and the Agreeableness Trait of Personality. It also showed a significant relationship between Parents Communication Attachment and Extraversion, Agreeableness and Conscientiousness. We also found a significant relationship between Parents' Alienation Attachment and Conscientiousness, Neuroticism and Openness. The study informs society about the need to increase awareness about the importance of knowing attachment styles and personality traits as both impact individuals' lives

    Stepwise complexometric determination of aluminium, titanium and iron concentrations in silica sand and allied materials

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    <p>Abstract</p> <p>Background</p> <p>This study aimed at measuring the quantities of Al, Ti and Fe in silica sand and allied materials employing a complexometric method in the same analyte and a stepwise indirect titration with EDTA. The method involves the complexation of Al, Ti and Fe with excess EDTA and the selective de-complexation of TiO-EDTA and Al-EDTA complexes with tartaric acid and NaF respectively. In addition to its simplicity, rapidity and accuracy, the proposed method does not require the use of a separation technique or any sophisticated instrumentation.</p> <p>Results</p> <p>Each of the test samples were analyzed five times using the proposed method. The method's accuracy was confirmed by analyzing the US National Institute of Standards and Technology's (NIST) Standard Reference Materials (SRM) 81a, 89 and IPT SRM 61 using the procedure proposed, in addition to analyzing Ti and Fe levels by spectrophotometry and that of Al by complexometry.</p> <p>Conclusion</p> <p>The study shows that there is good agreement between the proposed and existing methods. The standard deviations of the measurements were calculated by analyzing five replicates of each sample, and were found to be less than 1.5% in our method.</p
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