244 research outputs found

    Watermarking Using Decimal Sequences

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    This paper introduces the use of decimal sequences in a code division multiple access (CDMA) based watermarking system to hide information for authentication in black and white images. Matlab version 6.5 was used to implement the algorithms discussed in this paper. The advantage of using d-sequences over PN sequences is that one can choose from a variety of prime numbers which provides a more flexible system.Comment: 8 pages, 9 figure

    Watermarking using decimal sequences

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    This thesis introduces the use of decimal sequences in watermarking to hide information for authentication. The underlying system is based on code division multiple access (CDMA), which is a form of spread spectrum communication. Different algorithms for the use of decimal sequences have been formulated for use in black and white images. The watermark is spread across the carrier image by using the d- sequences of optimal period and retrieval is made by the use of correlation. Matlab version 6.5 was used to implement the algorithms discussed in this thesis. The advantage of using d-sequences over PN sequences is that one can choose from a variety of prime numbers which provides a more flexible system. Different methods for adding the random sequence to the image were investigated and results for random shifts and cyclic shifts have also been discussed

    Effect of Inhalation Steroids in Children with Coexistent Atopic Disorders & Nephrotic Syndrome on Prevention of Relapses of Nephrotic Syndrome

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    In many nephrotic syndrome children, it has been observed that onset of rhinitis and/or wheezing attacks precipitate the relapseof nephrotic syndrome. This association is known since long time. We decided to observe the response of inhalation steroids inprevention of relapses of nephrotic syndrome in children who presented with frequently relapsing nephrotic syndrome andcoexistent atopic disorders

    Role of MMP-2, MMP-9 and VEGF as serum biomarker in early prognosis of renal cell carcinoma

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    Introduction: Renal cell carcinoma epitomizes a diversified group of tumors which contributes more than 15,000 deaths annually worldwide. In spite of tremendous efforts to identify prognostic factors apart from grade, histology and tumor size, they are not so obvious yet to fulfill the requirement. In this study, the prognostic role of serum matrix metalloproteinase (MMP)-2, 9, and vascular endothelial growth factor (VEGF) levels in patients with pre and postoperative renal cell carcinoma are evaluated to use as biomarker.Patients and methods: A total of 100 patients with a diagnosis of renal cell carcinoma included in the study. Additionally, hundred healthy kidney donors enrolled as control, serum MMP-2, MMP-9, and VEGF levels were analyzed in the serum of post and preoperative patients and parallel in control serum samples by ELISA method.Result: Most of the patients with RCC were found to have high concentrations of serum MMP-2, MMP-9, and VEGF. The levels of MMP-2 in the serum of preoperative patients ranged from 627 to 1117 ng/ml (833.90 ± 111.91), postoperative MMP-2 range 302–913 (553.02 ± 150.08), control range 122–384 (228.33 ± 72.52). In MMP-9 pre-operative range 619–1233 (862.32 ± 119.77), post-operative range 124–909 (552.88 ± 151.91) and control range 42–467 (245.44 ± 116.52 and in VEGF preoperative range was 0.792–2.214 (1.35 ± 0.36), postoperative range was 0.315–1.917 (0.81 ± 0.46) and in control it was 0.01–0.39 (0.10 ± 0.09). We observed that preoperative levels of all three markers, were significantly increased if compared with postoperative and control levels (P = 0.001) however, no any significant correlation found when the levels correlated with grade, stage, size, and type for MMP-2 and MMP-9, but VEGF shows some significance in comparison

    Wetting transitions on superhydrophobic auxetic metamaterials

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    Superhydrophobicity plays a pivotal role in numerous applications. Recently, we have demonstrated the potential of auxetic metamaterials in creating superhydrophobic materials with unique wetting properties. However, the superhydrophobic properties are lost when the liquid penetrates into the surface structure. Understanding the conditions for droplet penetration is crucial for advancing wetting control. Here, we experimentally identify the transition from droplet suspension to full-penetration on an auxetic bowtie/honeycomb lattice membrane. We develop a comprehensive physical model surface representing different states of strain, ranging from auxetic to conventional lattice membranes, and consider the wetting as the liquid surface tension is varied using water/ethanol mixtures. By examining the interplay between contact angle and lattice structure, we gain valuable insights into the conditions for droplet suspension and full-penetration. Additionally, we develop a simple touch test to discern whether a droplet has effectively fully penetrated the structure, providing a practical and efficient means of distinguishing the different wetting states (suspended or partially penetrating vs fully penetrating)

    Polymorphism of GSTM1 and GSTT1 genes in prostate cancer: A study from North India

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    BACKGROUND: Glutathione-S-transferases (GSTs) are active in the detoxification of wide variety of endogenous or exogenous carcinogens. The genetic polymorphisms of GSTM1 and GSTT1 genes have been studied earlier to evaluate the relative risk of various cancers. AIM, SETTING AND DESIGN: In the present study, we examined the association of the GSTM1 and GSTT1 gene polymorphisms with sporadic prostate cancer patients in north Indian population. MATERIAL AND METHODS: This case control study was undertaken over a period of 24 months and included 103 prostate cancer patients and 117 controls; both patients and controls originated from northern part of India. The GSTT1 and GSTM1 genotypes were identified by multiplex PCR in peripheral blood DNA samples. STATISTICAL ANALYSIS: Difference in genotype prevalence and association between case and control group were assessed by the Chi square and Fisher Exact tests. RESULTS: Frequencies of null genotypes in GSTT1 and GSTM1, was 11% (13/117) and 30% (35/117) respectively in control individuals. The frequencies of GSTT1 and GSTM1 null genotypes in prostate cancer patients were 34% (35/103) and 53% (55/103) respectively. CONCLUSION: Our study demonstrates that the null genotypes of GSTT1 and GSTM1 are substantially at higher risk for prostate carcinoma as compared to the normal healthy controls. The GSTT1 and GSTM1 null genotypes did not show significant association with tobacco usage in prostate cancer patients. However, the null genotypes were significantly stratified in 50-60 year-old patients when incidence of prostate cancer is high

    Prognosticfactors in patients with renal cell carcinoma: Is TNM (1997) staging relevant in Indian subpopulation?

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    BACKGROUND: RCC (Renal Cell Carcinoma) is a common genitourinary malignancy, but its behavior has not been studied in the Indian Subpopulation. AIMS: The aim of this study was to assess the validity of 1997 AJCC TNM staging in Indian subpopulation and also to identify independent predictors for survival in patients having RCC. SETTING AND DESIGN: Retrospective uncontrolled analysis of patients with RCC was performed at our centre. MATERIAL AND METHODS: Medical records of patients of undergoing radical nephrectomy at our center between 1994 to August 2003 were identified retrospectively. Medical records of 178 patients were available for analysis. Patient characteristics, preoperative imaging and surgical details were reviewed. Each tumor was staged according to the 1997 AJCC TNM classification. Nuclear grade was assigned according to the Fuhrman\u2032s grading system. STATISTICAL METHODS: Statistical analysis was performed using statistical software and descriptive statistics and survival functions were obtained. Univariate and multivariate analysis of factors affecting outcome of the patient were performed. RESULTS: Mean follow up period was 42.3 months (range 3 to 108 months). Stage wise 5-year Cancer specific survival was 87.2% in stage 1 disease, 74.3% in stage 2, 36.4% in stage 3 and 3.1% in stage 4. Univariate analysis revealed that stage, grade and lymph node status were statistically significant (P=0.009, 0.007 and 0.003 respectively). Sub-classifying stage 1 tumors between tumor of less than 4 cm. and more than 4 cm. did not reveal any statistically significant difference in survival (P=0.32). Multivariate analysis model revealed that Fuhrman\u2032s grade and lymph node status were statistically significant (P=0.007 and 0.002 respectively). CONCLUSION: This study validates the TNM (1997) staging for RCC as having significant survival impact in the Indian subpopulation. Sub-classifying stage 1 tumors between tumor of less than 4 cm. and more than 4 cm is not of much importance. Nuclear grade and lymph node involvement are important independent predictors of survival. Organ confined tumors with high nuclear grades need to be followed up more rigorously

    Transforming Auxetic Metamaterials into Superhydrophobic Surfaces

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    Superhydrophobic materials are often inspired by nature, whereas metamaterials are engineered to have properties not usually occurring naturally. In both, the key to their unique properties is structure. Here, it is shown that a negative Poisson's ratio (auxetic) mechanical metamaterial can transform into a unique superhydrophobic material. When stretched, its surface has the counterintuitive property that it also expands in the orthogonal lateral direction. The change in the solid surface fraction as strain is applied is modeled, and it is shown that it decreases as the space between solid elements of the auxetic lattice expands. This results in a unique dependence of the superhydrophobicity on strain. Experimental models are constructed to illustrate the relationship between different states of strain and superhydrophobicity as the lattice transitions from an auxetic to a conventional structure. The findings offer a new approach to designing superhydrophobic materials for self‐cleaning surfaces, droplet transportation, droplet encapsulation, and oil–water separation
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