599 research outputs found

    Acral lentiginous melanoma. A retrospective study

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    Background: Acral lentiginous melanoma (ALM) carries one of the worst prognoses among other subtypes. This malignant tumor is found on the distal limbs and is usually detected at late stages. Hereby, the authors present their experience on this melanoma subtype. Methods: A retrospective study was conducted. Data were extracted from patients’ medical records and from phone interviews. Results: A total of 43 patients were included in the study. The main signs and symptoms disclosed by the patients were bleeding (41.9%), size greater than 6 mm (41.9%), change in size (37.2%), change in shape (30.2%), rise above the surface of the skin (27.9%), change in color (20.9%), irregular borders (16.3%), and inflammation (16.3%). The first healthcare professional consulted was a general practitioner or a dermatologist in the majority of cases (88.3%). Only 44.2% of the patients were sent by their first physician for a biopsy, whereas 30.3% were sent by the 2nd physician. 14 patients underwent biopsy within 1 month from the first appointment with a physician, while 20 patients within 3 months and 9 patients within 6 months. Only 7 patients sought medical attention in the first 3 months; 21 patients sought medical care between 3 months and one year from the appearance of the lesion, while the remaining 15 patients waited more than a year. Conclusions: One of the major issues found in ALM is represented by the diagnostic delay; this may be due to either the patients or the physicians’ failure to recognize warning signs

    A cross layer framework to mitigate a joint MAC and routing attack in multihop wireless networks

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    It is well known that security threats, in wireless ad hoc networks, are becoming a serious problem which may lead to harmful consequences on network performance. Despite that, many routing protocols still not resilient to such threats or their countermeasures are not efficient. Moreover, the vulnerability of MAC layer protocols to some attacks exacerbates the damage caused by the threats at higher layers. Therefore, cooperation between layers in compulsory to face such devastating threats. In this paper, we address a cross-layer attack targeting proactive routing protocols, which is launched at the routing level and reinforced at the MAC layer in order to amplify the resulted damage. We demonstrate that this attack can severely compromise the routing protocols and lead to large data packets loss. We particularly analyze it under the Optimized Link State Routing (OLSR) protocol in detail and propose a lightweight solution to cope with it. The simulation results confirm the efficiency of this solution. ©2009 IEEE

    An acknowledgment-based scheme to defend against cooperative black hole attacks in optimized link state routing protocol

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    In this paper, we address the problem of cooperative black hole attack, one of the major security issues in mobile ad hoc networks. The aim of this attack is to force nodes in the network to choose hostile nodes as relays to disseminate the partial topological information, thereby exploiting the functionality of the routing protocol to retain control packets. In optimized link state routing (OLSR) protocol, if a cooperative black hole attack is launched during the propagation of topology control (TC) packets, the topology information will not be disseminated to the whole network which may lead to routing disruption. In this paper, we investigate the effects of the cooperative black hole attack against OLSR, in which two colluding MPR nodes cooperate in order to disrupt the topology discovery. Then we propose an Acknowledgment based technique that overcomes the shortcomings of the OLSR protocol, and makes it less vulnerable to such attacks by identifying and then isolating malicious nodes in the network. The simulation results of the proposed scheme show high detection rate under various scenarios. ©2008 IEEE

    Prevalence of mastocytosis and hymenoptera venom allergy in the United States

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    Background : Mastocytosis is a risk factor for hymenoptera venom anaphylaxis (HVA). Current guidelines recommend measuring tryptase in HVA patients and that those with mastocytosis pursue lifelong venom immunotherapy (VIT). Available data on HVA and mastocytosis largely derives from European single-center studies and the prevalence of HVA with and without mastocytosis in the United States (US) is unknown. Objective : We sought to determine the prevalence of HVA and mastocytosis in the US using an insurance claims database and evaluate the impact of mastocytosis on VIT in HVA patients in a US cohort. Methods :The IBM Watson Database, consisting of insurance claims from approximately 27 million US patients in 2018, was queried to identify patients with HVA and/or mastocytosis. Further, a retrospective study of 161 patients undergoing VIT between 2015 – 2018 at the University of Michigan (U-M) was conducted. Results :In the IBM Watson Database, the prevalence of HVA was 167 per 100,000 (0.167%) and the prevalence of mastocytosis 10 per 100,000 (0.010%) overall and 97 per 100,000 (0.097%) among those with HVA. Mastocytosis showed a 9.7-fold increase among HVA patients versus the general population. In the U-M cohort, 2.6% of VIT patients had mastocytosis. Tryptase level did not correlate with venom reaction severity but was higher in patients with systemic VIT reactions. Conclusions :We observed a lower US HVA prevalence than previously reported. Mastocytosis was more common in US HVA patients, though at lower rates than previously reported. In VIT patients there was no correlation between tryptase level and reaction severity. Key words :Tryptasevenom allergyvenom immunotherapyanaphylaxismastocytosismast cell activation syndromemast cell disease Abbreviations Hymenoptera venom allergyHVAUnited StatesUSVenom immunotherapyVITMast Cell DiseaseMCDAmerican Academy of Allergy, Asthma, and ImmunologyWOS:000717466600002Scopus - Affiliation ID: 60105072PMID: 33895259Science Citation Index ExpandedQ1ArticleUluslararası iƟbirliği ile yapılan - EVETKasım2021YÖK - 2021-2

    Epidemiological findings on interventional cardiology procedures during the COVID-19 pandemic: A multi-center study

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    Background: The rates of in-hospital mortality following percutaneous interventional procedures (PIP) during the COVID-19 pandemic period compared to the non-pandemic period has not been reported so far. Methods: We retrospectively enrolled all consecutive patients admitted for PIP across five centers from February 2020 to May 2020. Results: A total of 4092 PIP were performed during the reference periods. The total number of procedures dropped from 2380 to 1712 (28.0% reduction). Overall in-hospital mortality increased from 1.1% in 2019, to 2.6% in 2020 (63% relative increase). Conclusion: During the COVID-19 pandemic, in-hospital all-cause mortality significantly increased in patients admitted for cardiological PIP

    Wavelet Based Simulation and Analysis of Single and Multiple Power Quality Disturbances

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    Improving power quality disturbance (PQD) detection and automatic classification has been a major concern ever since the emergence of sensitive non-linear devices. The role of distributed generation in a power system is the main source of PQDs. Short-term and long-term duration single and multiple complex PQDs are difficult to monitor and need higher accuracy and time. This paper presents the analysis of different and distinctive combinations of PQDs. Variety of single and multiple PQD samples are generated using Matlab environment conferring to IEEE STD 1159-2009. Such disturbance samples are accurately detected and analyzed from waveform patterns using multi resolution analysis based discrete wavelet transform. The generation of samples and detection lies in fact that it can allow the feature extraction process for the training/testing sample features for machine learning based automatic recognition of disturbance types

    COVID-19 lessons for climate change and sustainable health

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    The drivers underpinning the emergence of SARS-CoV-2 and climate change attest to the fact that we are now living in the Anthropocene Epoch, with human activities significantly impacting and altering the global ecosystem. Here, we explore the historical context of zoonoses, the effect of anthropogenic climate change and interrelated drivers on the emergence of, and response to emerging infectious diseases. We call attention to an urgent need for inculcating a One Health research agenda that acknowledges the primary interconnection between animals, humans, pathogens, and their collective milieus to foster long term resilience across all systems within our shared planetary environment.</jats:p

    Hepatocellular carcinoma in Pakistan: where do we stand?

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    Context: From the 1970s till the mid 1990s, hepatitis B was the most common etiological factor for hepatocellular carcinoma (HCC) in Pakistan. Afterwards, a shift in HCC etiology was observed with a steady rise in hepatitis C virus (HCV) related HCC cases. HCV-3a, which is the most prevalent genotype, is also most frequent in HCV related HCC. There was an increase in the proportion of non-B non-C (NBNC) HCC cases as well, which might be attributed to an increase in non-alcoholic fatty liver disease. Evidence Acquisition: The age-standardized rate for HCC is 7.64/100 000 in males and 2.8/100 000 in females. Male to female ratio is 3.6:1. Usual age of presentation is in the fifth and sixth decade. Most patients present with advanced disease, as they are not in a regular surveillance program. This is more so for patients with NBNC chronic liver disease. As many sonologists in Pakistan are practicing without sufficient training to pick up early lesions, alpha-fetoprotein is still recommended to compliment ultrasound in the surveillance of HCC. Results: Majority of HCC patients present with nonresectable disease. Interventions such as transarterial chemoembolization, radiofrequency ablation, resection and chemotherapy including sorafenib are available in selected centers. Pakistan appears to be in an area of intermediate endemicity for HCC. There is a need for population based epidemiological studies to estimate the exact disease burden. Conclusions: Measures to prevent the spread of hepatitis C and B can slow down the epidemic rise in the incidence of HCC in the coming decades. There is a need to implement a proper surveillance program to identify HCC cases at an early stage
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