Private search over big data leveraging distributed file system and parallel processing

As the new technologies recently became widespread, enormous amount of data started to be generated in very high speeds and stored in untrusted servers. The big data concept covers not only the exceptional size of the datasets, but also high data generation rate and large variety of data types. Although the Big Data provides very tempting benefits, the security issues are still an open problem. In this thesis, we identify security and privacy problems associated with a certain big data application, namely secure keyword-based search over encrypted cloud data and emphasize the actual challenges and technical difficulties in the big data setting. More specifically, we provide definitions from which privacy requirements can be derived. In addition, we adapt an existing work on privacy-preserving keyword-based search method, which is one of the fundamental operations that can be performed over encrypted data, to the big data setting, in which, not only data is huge but also changing and accumulating very fast. Therefore, in the big data setting, a secure index that allows search over encrypted data should be constructed and updated very fast in addition to an efficient and effective keyword-based search operation method. Our proposal is scalable in the sense that it can leverage distributed file systems and parallel programming techniques such as the Hadoop Distributed File System (HDFS) and the MapReduce programming model to work with very large datasets. We also propose a lazy idf-updating method that can efficiently handle the relevancy scores of the documents in dynamically changing and large datasets. We empirically show the efficiency and accuracy of the method through extensive set of experiments on real dat

Comparison of HCV core antigen and anti-HCV with HCV RNA results

Background: The measurement of anti-HCV antibodies using immunological methods and the confirmation of viral nuclear acid based on molecular methods is important in diagnosis and follow-up of the HCV infection.Objectives: In this study, we aimed to analyse HCV core Antigen positivity among anti-HCV antibody positive sera to determine the significance of testing of HCV core Ag for the laboratory diagnosis of HCV infection, by considering the correlation between serum HCV core Ag and HCV RNA levels.Methods: 115 patients suspected of having hepatitis C and who were positive for anti-HCV antibody were investigated using chemiluminescent and molecular methods. Anti-HCV antibody, HCV core Ag and HCV RNA levels were detected by the Vitros ECiQ immunodiagnostic system, Architect i2000 system and RT-PCR, respectively.Results: The sensitivity, specificity, positive and negative predictive values and accuracy rate of HCV core Antigen assay were detected as 86.5%(83/96), 100%(19/19), 100%(83/83), 59.4%(19/32), 88.7%(102/115) respectively.Conclusion: HCV core Ag assay could be used for diagnosis of HCV infection as it is easy to perform, cost-effective, has high specificity and positive predictive value. However, it should be kept in mind that it may have lack of sensitivity and negative predictive value.Key Words: HCV, anti-HCV antibody, HCV core Ag, HCV RN

Private search over big data leveraging distributed file system and parallel processing

In this work, we identify the security and privacy problems associated with a certain Big Data application, namely secure keyword-based search over encrypted cloud data and emphasize the actual challenges and technical difficulties in the Big Data setting. More specifically, we provide definitions from which privacy requirements can be derived. In addition, we adapt an existing work on privacy-preserving keyword-based search method to the Big Data setting, in which, not only data is huge but also changing and accumulating very fast. Our proposal is scalable in the sense that it can leverage distributed file systems and parallel programming techniques such as the Hadoop Distributed File System (HDFS) and the MapReduce programming model, to work with very large data sets. We also propose a lazy idf-updating method that can efficiently handle the relevancy scores of the documents in a dynamically changing, large data set. We empirically show the efficiency and accuracy of the method through extensive set of experiments on real data

An alternative approach for daily perineal care of patients with indwelling urinary catheterization: Photodynamic inactivation with cationic porphyrin derivatives

Background: Catheter-associated urinary tract infections (CAUTI) constitute a significant portion of healthcare-associated infections. Using antiseptic for routine daily perineal care of patients with IUC may reduce CAUTIs. Aim: This study aimed to examine antimicrobial photodynamic inactivation (aPDI) against clinical isolates for use in the daily perineal care of patients with IUC. In addition, it was also aimed to compare the antimicrobial activities of aPDI and 0.1% chlorhexidine gluconate. Methods:  In this in-vitro study, cationic porphyrin derivatives (CPDs) were used as photosensitizers in the experiments. CPDs, named PM, PE, PN, and PL were synthesized by the researchers. A diode laser device emitting light with a wavelength of 450 nm (blue light) was used as the light source. Methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli and Klebsiella pneumoniae with multidrug-resistant (MDR) properties and Candida albicans were used.  Photosensitizer (PS), aPDI, light (L), and control (C) groups in aPDI experiments; control (C) and chlorhexidine gluconate 0.1% groups were used in the chlorhexidine gluconate experiments. Survival was calculated based on CFU/mL in the control group. Results: In experiments, combinations of 25 J/cm² with 6.25 and 3.125 µM PM, PE reduced E. coli, K. pneumoniae, MRSA, and C. albicans survival in the range of 8.70 to 11.53 log₁₀. In aPDI experiments performed with 6.25 and 3.125 µM PN and PL concentrations at the same energy density, reductions in the range of 4.41 to 0.17 log₁₀ were observed in all four clinical isolates. In experiments where 1.5625 µM concentration was used, survival decreased in the range of 8.29 to 10.87 log₁₀ in PM and PE, while antimicrobial activity was limited in PN and PL. In the 0.1% chlorhexidine gluconate experiments, the survival reduction in all four clinical isolates ranged from 8.87 to 10.24 log₁₀. Conclusion: For PM and PE, a very strong aPDI was obtained in C. albicans, E.coli, K. pneumoniae, and MRSA at low concentrations and energy density. The same antimicrobial activity was found in experiments using 0.1% chlorhexidine gluconate. In this context, we would like to inform you that aPDI to be performed with a combination of 25 J/cm² at 6.25 and 3.125 µM concentrations of PM and PE has the potential to be an antiseptic in the daily perineal care of patients with IUC

Comparison of polymerase chain reaction-restriction enzyme analysis method and DNA sequence analysis results in the identification of non-tuberculous mycobacteria

The typing of non-tuberculous mycobacteria (NTM) is important from a clinical and epidemiological perspective. The polymerase chain reaction-restriction enzyme analysis (PRA) method and DNA sequence analysis method were utilized to target a gene region that codes the 65-kDa heat-shock protein for typing 150 suspected NTM samples isolated from the respiratory tract. Mycobacterium abscessus, Mycobacterium xenopi, Mycobacterium fortuitum, and Mycobacterium peregrinum were most frequently found by both methods. Six isolates that could not be defined by the PRA method were defined as Nocardia cyriacigeorgica, Nocardia abscessus, and Mycobacterium intracellulare by DNA sequence analysis. Discordance between the results of the two methods was observed for only one isolate. The isolate that was defined as Mycobacterium gordonae type 6 by the PRA method was defined as Mycobacterium senegalense by sequence analysis. The PRA method is simple and gives rapid results. Compared with DNA sequence analysis, it gives consistent and reliable results up to a ratio of 90%. DNA sequence analysis is the gold standard method in which all strains can be defined. However, given our laboratory conditions, its disadvantage is that it takes longer to reach a diagnosis than through the PRA method

THE EVALUATION OF ETIOLOGICAL FACTORS IN URTICARIA

Amaç: Urtikarya sık görülen, tanısı kolay konulabilen ancak oldukça değişken etyolojik faktörlerin saptanmasının zor olduğu bir dermatozdur. Bu çalışmada kliniğimizde urtikarya tanısıyla izlenmiş olan hastalarda saptanan etyolojik faktörlerin değerlendirilmesi amaçlanmıştır. Gereç ve yöntem: Bu retrospektif çalışmada 2000-2007 yılları arasında Dokuz Eylül Üniversitesi Tıp Fakültesi Dermatoloji Kliniği'nde yatarak tedavi gören urtikarya tanısı almış 127 olguda saptanan etyolojik etmenler araştırılmıştır. Bulgular: Ayrıntılı anamnez ve etyolojiye yönelik yapılan tetkikler sonucunda özellikle gıdalar, ilaçlar ve infeksiyonlar olmak üzere 92 (%72,4) hastada en az 1 veya daha fazla olası tetikleyici etken saptanırken, 35 (%27,6) hastada tetikleyici etken saptanamamıştır. Sonuç: Çalışmada elde edilen bulgular ışığında; urtikaryalı olguların değerlendirilmesinde infeksiyonlar, ilaçlar ve gıdalar başta olmak üzere olası tetikleyici faktörlerin alınacak ayrıntılı anamnezde yer almasının önemi vurgulanmıştır. Objective: Urticaria is a common skin disease which is easily diagnosed. In contrast to the ease of its diagnosis, the underlying etiologic factors are often difficult to determine. In the present study, we aimed to evaluate the etiologic factors in patients with urticaria who were followed-up by our clinic. Material and method: In this retrospective study; 127 in-patients with urticaria who were followed up in Dokuz Eylül University Medical School Department of Dermatology between the years 2000-2007 were re-evaluated to outline the established etiologic factors. Results: Detailed anamnesis and laboratory investigations revealed at least one etiological factor in 92 (72.4%) patients, especially foods, drugs and infections. On the other hand 35 (27.6%) patients had no associating triggering factors. Conclusion: In this study, the importance of a detailed history regarding triggering factors such as infections, drugs and foods in the evaluation of patients with urticaria was emphasized

Clinical Experience for Modified Thoracoabdominal Nerve Block Through Perichondrial Approach (M-TAPA) in Five Patients. Dermatomal Evaluation and Application of Different Volumes: A Case Series and Review of Literature

Thoracoabdominal nerves block through perichondrial approach (TAPA) is a novel block and provides abdominal analgesia. TAPA block targets the both anterior and the lateral branches of the thoracoabdominal nerves. Modified-TAPA (M-TAPA) was defined due to the need for blocking certain dermatomes depending on the surgical incision sites. In the literature, the knowledge about the efficiency and dermatomal coverage of M-TAPA is limited. In this case series, we want to report our experiences with this issue

The presence of upper extremity problems and the effect on quality of life in breast cancer patients who undergone breast surgery and axillary dissection

Aim: The purpose of this study was to determine the prevalence of upper extremity problems in patients who had undergone breast cancer surgery, to compare the risk factors associated with these problems and to investigate their effects on quality of life. Materials and Methods: One hundred thirty-two patients who had undergone either modified radical mastectomy or breast conserving surgery (lumpectomy) were enrolled to the study. Lymphedema, shoulder pain and restriction of shoulder motion were considered as upper extremity problems. Type of surgery, body mass index (BMI), radiotherapy, chemotherapy, disease stage and dominant hand involvement were recorded. The World Health Organisation (WHO) Quality of Life-BREF-Turkish Version (WHOQOLBREF- TR) was used for the assessment of quality of life. Results: Shoulder pain was the most common symptom (45.5%), followed by lymphedema (34.8%) and shoulder motion restriction (22%). No significant relation was found between lymphedema and age, type of surgery, restriction of shoulder motion, pain and dominant hand involvement. Increased BMI, treatment with chemotherapy or radiotherapy, advanced-disease stage and lymph node involvement were associated with lymphedema (p< 0.05). It was seen that doing regular exercise had positive effect on lymphedema, pain and shoulder motion restriction reduction (p<0.05). Lymphedema, pain and shoulder motion restriction were related with physical and psychological subgroups of WHOQOL-BREF TR, whereas shoulder motion restriction was also associated with the environmental subgroup (p<0.05). When lymphedema, pain and shoulder motion restriction was searched for to determine which one was more effective on quality of life shoulder pain had negative effect in the physical and psychological subgroups; motion restriction had negative effect in the physical subgroup, whereas lymphedema did not affect the quality of life subgroups. Exercise also had positive contribution to environmental and psychological subgroups of quality of life (p<0.05). Conclusion: Arm problems are frequently encountered following breast surgery and affect the daily living of patients by decreasing their quality of life. The major aim in these patients must be taking preventive precautions and preserving the quality of life by minimizing complications with regular follow-up. Turk J Phys Med Re hab 2011;57:186-92. © Turkish Journal of Physical Medicine and Rehabilitation, Published by Galenos Publishing