48 research outputs found

    A unit-based symbolic execution method for detecting memory corruption vulnerabilities in executable codes

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    Memory corruption is a serious class of software vulnerabilities, which requires careful attention to be detected and removed from applications before getting exploited and harming the system users. Symbolic execution is a well-known method for analyzing programs and detecting various vulnerabilities, e.g., memory corruption. Although this method is sound and complete in theory, it faces some challenges, such as path explosion, when applied to real-world complex programs. In this paper, we present a method for improving the efficiency of symbolic execution and detecting four classes of memory corruption vulnerabilities in executable codes, i.e., heap-based buffer overflow, stack-based buffer overflow, use-after-free, and double-free. We perform symbolic execution only on test units rather than the whole program to avoid path explosion. In our method, test units are considered parts of the program's code, which might contain vulnerable statements and are statically identified based on the specifications of memory corruption vulnerabilities. Then, each test unit is symbolically executed to calculate path and vulnerability constraints of each statement of the unit, which determine the conditions on unit input data for executing that statement or activating vulnerabilities in it, respectively. Solving these constraints gives us input values for the test unit, which execute the desired statements and reveal vulnerabilities in them. Finally, we use machine learning to approximate the correlation between system and unit input data. Thereby, we generate system inputs that enter the program, reach vulnerable instructions in the desired test unit, and reveal vulnerabilities in them. This method is implemented as a plugin for angr framework and evaluated using a group of benchmark programs. The experiments show its superiority over similar tools in accuracy and performance

    Loss of Guide Wire as an Important Complication of Central Venous Catheterization; a Case Report

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    Many critically ill patients need aggressive procedures, such as central venous catheterization. The complication rate of central venous line placement is estimated to be 15%. Common complications include arterial puncture, hematoma, pneumothorax, hemothorax, arrhythmia, thoracic duct injury, infection, and thrombosis. Cardiac tamponade, pericardial effusions, pleural effusions, air or guidewire embolisms, and lost guide wires are rare but severe complications. Here we report a case of lost guide wire following central venous line insertion

    Review of possible mechanisms of analgesic effect of herbs and herbal active ingredient

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    Pain is a distressing feeling caused by damage to different tissues. Consequently the person reacts, and tries to remove the painful stimulus. On the other hand, prostaglandins contribute to the emergence of pain. These compounds are formed and secreted by cyclogenase 2 or COX-2 enzymes. It is through inhibiting these enzymes that most of the analgesic medications act. Thus, this study aims to investigate and review some of the scientific findings on analgesic effects and possible active ingredients and analgesic mechanisms of these herbs. Result: Nowadays one of the methods to control pain is using non-steroid anti-inflammatory medications. Although the analgesic effects of these medications emerge relatively fast, but their side effects are considered to be a limiting factor in their usage. Therefore researchers are constantly in the search of new medications with less side effects. In recent years the tendency to use herbal medications has significantly increased in the treatment and prediction of these diseases. Since analgesic medications show a wide range of complications therefore using secondary herbal compounds may be an appropriate alternative for chemical medications. In this respect, many analgesic effects of herbal medications have been brought into attention and it is believed that many natural compounds may serve as new medical compounds.Conclusion: Regarding the importance of research about pain and the effort in increasing awareness in this respect and also regarding the problems caused by using opioid medications, it is necessary to find herbal medications

    Achievements of the Cochrane Iran Associate Centre: Lessons Learned

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    Healthcare decision-making is a process that mainly depends on evidence and involves increasing numbers of stakeholders, including the consumers. Cochrane evidence responds to this challenge by identifying, appraising, integrating and synthesizing high-quality evidence. Recently, a collaborative effort has been initiated in Iran with Cochrane to establish a representative local entity. A variety of multifaceted interventions were conducted according to Cochrane’s strategy to 2020, such as producing evidence, making Cochrane evidence accessible, advocating for evidence and building an effective and sustainable organization. In this report, the authors present the two and half year performance and achievements of Cochrane Iran based on a comprehensive and systematic approach. This case might be an example of health diplomacy, which is initiated by a successful international collaboration and proceed with recognizing the importance of adherence to the strategic action plans and goals

    CN2F: A Cloud-Native Cellular Network Framework

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    Upcoming 5G and Beyond 5G (B5G) cellular networks aim to improve the efficiency and flexibility of mobile networks by incorporating various technologies, such as Software Defined Networking (SDN), Network Function Virtualization (NFV), and Network Slicing (NS). In this paper, we share our findings, accompanied by a comprehensive online codebase, about the best practice of using different open-source projects in order to realize a flexible testbed for academia and industrial Research and Development (R&D) activities on the future generation of cellular networks. In particular, a Cloud-Native Cellular Network Framework (CN2F) is presented which uses OpenAirInterface's codebase to generate cellular Virtual Network Functions (VNFs) and deploys Kubernetes to disperse and manage them among some worker nodes. Moreover, CN2F leverages ONOS and Mininet to emulate the effect of the IP transport networks in the fronthaul and backhaul of real cellular networks. In this paper, we also showcase two use cases of CN2F to demonstrate the importance of Edge Computing (EC) and the capability of Radio Access Network (RAN) slicing

    The evaluation of a virtual education system based on the DeLone and McLean model:  A path analysis [version 2; referees: 3 approved]

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    Background: The Internet has dramatically influenced the introduction of virtual education. Virtual education is a term that involves online education and e-learning. This study was conducted to evaluate a virtual education system based on the DeLone and McLean model. Methods: This descriptive analytical study was conducted using the census method on all the students of the Nursing and Midwifery Department of Alborz University of Medical Sciences who had taken at least one online course in 2016-2017. Data were collected using a researcher-made questionnaire based on the DeLone and McLean model in six domains and then analyzed in SPSS-16 and LISREL-8.8 using the path analysis. Results: The goodness of fit indices (GFI) of the model represent the desirability and good fit of the model, and the rational nature of the adjusted relationships between the variables based on a conceptual model (GFI = 0.98; RMSEA = 0.014).The results showed that system quality has the greatest impact on the net benefits of the system through both direct and indirect paths (β=0.52), service quality through the indirect path (β=0.03) and user satisfaction through the direct path (β=0.73). Conclusions: According to the results, system quality has the greatest overall impact on the net benefits of the system, both directly and indirectly by affecting user satisfaction and the intention to use. System quality should therefore be further emphasized, to use these systems more efficiently

    Deleterious ABCA7 mutations and transcript rescue mechanisms in early onset Alzheimer's disease

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    Altres ajuts: The sponsors of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the report. The research was funded in part by the European Commission Seventh Framework Programme for research, technological development, and demonstration under grant agreement 305299 (AgedBrainSYSBIO), the Belgian Science Policy Office Interuniversity Attraction Poles program, the Alzheimer Research Foundation (SAO-FRA), the Flemish government-initiated Flanders Impulse Program on Networks for Dementia Research (VIND), the Flemish government-initiated Methusalem Excellence Program, the Research Foundation Flanders (FWO), the VIB Technology Fund, the University of Antwerp Research Fund, Belgium; European Regional Development Fund, the Italian Ministry of Health (Ricerca Corrente and RF-2010-2319722), and the Fondazione Cassa di Risparmio di Pistoia e Pescia grant (2014.0365).Premature termination codon (PTC) mutations in the ATP-Binding Cassette, Sub-Family A, Member 7 gene (ABCA7) have recently been identified as intermediate-to-high penetrant risk factor for late-onset Alzheimer's disease (LOAD). High variability, however, is observed in downstream ABCA7 mRNA and protein expression, disease penetrance, and onset age, indicative of unknown modifying factors. Here, we investigated the prevalence and disease penetrance of ABCA7 PTC mutations in a large early onset AD (EOAD)-control cohort, and examined the effect on transcript level with comprehensive third-generation long-read sequencing. We characterized the ABCA7 coding sequence with next-generation sequencing in 928 EOAD patients and 980 matched control individuals. With MetaSKAT rare variant association analysis, we observed a fivefold enrichment (p = 0.0004) of PTC mutations in EOAD patients (3%) versus controls (0.6%). Ten novel PTC mutations were only observed in patients, and PTC mutation carriers in general had an increased familial AD load. In addition, we observed nominal risk reducing trends for three common coding variants. Seven PTC mutations were further analyzed using targeted long-read cDNA sequencing on an Oxford Nanopore MinION platform. PTC-containing transcripts for each investigated PTC mutation were observed at varying proportion (5-41% of the total read count), implying incomplete nonsense-mediated mRNA decay (NMD). Furthermore, we distinguished and phased several previously unknown alternative splicing events (up to 30% of transcripts). In conjunction with PTC mutations, several of these novel ABCA7 isoforms have the potential to rescue deleterious PTC effects. In conclusion, ABCA7 PTC mutations play a substantial role in EOAD, warranting genetic screening of ABCA7 in genetically unexplained patients. Long-read cDNA sequencing revealed both varying degrees of NMD and transcript-modifying events, which may influence ABCA7 dosage, disease severity, and may create opportunities for therapeutic interventions in AD

    No supportive evidence for TIA1 gene mutations in a European cohort of ALS-FTD spectrum patients

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    We evaluated the genetic contribution of the T cell-erestricted intracellular antigen-1 gene (TIA1) in a European cohort of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) patients. Exonic resequencing of TIA1 in 1120 patients (693 FTD, 341 ALS, 86 FTD-ALS) and 1039 controls identified in total 5 rare heterozygous missense variants, affecting the TIA1 low-complexity domain (LCD). Only 1 missense variant, p.Met290Thr, identified in a familial FTD patient with disease onset at 64 years, was absent from controls yet received a combined annotation-dependent depletion score of 11.42. By contrast, 3 of the 4 variants also detected in unaffected controls, p.Val294Glu, p.Gln318Arg, and p.Ala381Thr, had combined annotation-dependent depletion scores greater than 20. Our findings in a large European patient-control series indicate that variants in TIA1 are not a common cause of ALS and FTD. The observation of recurring TIA1 missense variants in unaffected individuals lead us to conclude that the exact genetic contribution of TIA1 to ALS and FTD pathogenesis remains to be further elucidated
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