101 research outputs found

    Efficient Hardware Accelerator for IPSec Based on Partial Reconfiguration on Xilinx FPGAs

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    Abstract—In this paper we present a practical low-end embed-ded system solution for Internet Protocol Security (IPSec) imple-mented on the smallest Xilinx Field Programmable Gate Array (FPGA) device in the Virtex 4 family. The proposed solution supports the three main IPSec protocols: Encapsulating Security Payload (ESP), Authentication Header (AH) and Internet Key Exchange (IKE). This system uses efficiently hardware-software co-design and partial reconfiguration techniques. Thanks to utilization of both methods we were able to save a significant portion of hardware resources with a relatively small penalty in terms of performance. In this work we propose a division of the basic mechanisms of IPSec protocols, namely cryptographic algorithms and their modes of operation to be implemented either in software or hardware. Through this, we were able to combine the high performance offered by a hardware solution with the flexibility of a software implementation. We show that a typical IPSec protocol configuration can be combined with Partial Reconfiguration techniques in order to efficiently utilize hardware resources. Index Terms—Partial reconfiguration; IPSec; Xilinx FPGA I

    Treatment of focal degenerative cartilage defects with polymer-based autologous chondrocyte grafts: four-year clinical results

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    INTRODUCTION: Second-generation autologous chondrocyte implantation with scaffolds stabilizing the grafts is a clinically effective procedure for cartilage repair. In this ongoing prospective observational case report study, we evaluated the effectiveness of BioSeed-C, a cell-based cartilage graft based on autologous chondrocytes embedded in fibrin and a stable resorbable polymer scaffold, for the treatment of clinical symptomatic focal degenerative defects of the knee. METHODS: Clinical outcome after 4-year clinical follow-up was assessed in 19 patients with preoperatively radiologically confirmed osteoarthritis and a Kellgren-Lawrence score of 2 or more. Clinical scoring was performed before implantation of the graft and 6, 12, and 48 months after implantation using the Lysholm score, the Knee injury and Osteoarthritis Outcome Score (KOOS), the International Knee Documentation Committee (IKDC) score, and the International Cartilage Repair Society (ICRS) score. Cartilage regeneration and articular resurfacing were assessed by magnetic resonance imaging (MRI) 4 years after implantation of the autologous cartilage graft. RESULTS: Significant improvement (P < 0.05) of the Lysholm and ICRS scores was observed as early as 6 months after implantation of BioSeed-C and remained stable during follow-up. The IKDC score showed significant improvement compared with the preoperative situation at 12 and 48 months (P < 0.05). The KOOS showed significant improvement in the subclasses pain, activities of daily living, and knee-related quality of life 6 months as well as 1 and 4 years after implantation of BioSeed-C in osteoarthritic defects (P < 0.05). MRI analysis showed moderate to complete defect filling with a normal to incidentally hyperintense signal in 16 out of 19 patients treated with BioSeed-C. Two patients without improvement in the clinical and MRI scores received a total knee endoprosthesis after 4 years. CONCLUSIONS: The results show that the good clinical outcome achieved 1 year after implantation of BioSeed-C remains stable over the course of a period of 4 years and suggest that implanting BioSeed-C is a promising treatment option for the repair of focal degenerative defects of the knee

    The role of p53 dysfunction in colorectal cancer and its implication for therapy

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    Colorectal cancer (CRC) is one of the most common and fatal cancers worldwide. The carcinogenesis of CRC is based on a stepwise accumulation of mutations, leading either to an activation of oncogenes or a deactivation of suppressor genes. The loss of genetic stability triggers activation of proto-oncogenes (e.g., KRAS) and inactivation of tumor suppression genes, namely TP53 and APC, which together drive the transition from adenoma to adenocarcinoma. On the one hand, p53 mutations confer resistance to classical chemotherapy but, on the other hand, they open the door for immunotherapy, as p53-mutated tumors are rich in neoantigens. Aberrant function of the TP53 gene product, p53, also affects stromal and non-stromal cells in the tumor microenvironment. Cancer-associated fibroblasts together with other immunosuppressive cells become valuable assets for the tumor by p53-mediated tumor signaling. In this review, we address the manifold implications of p53 mutations in CRC regarding therapy, treatment response and personalized medicine

    Incident dementia in elderly patients with nonalcoholic fatty liver disease in Germany

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    Dementia and NAFLD are two frequent conditions that share underlying risk factors mainly in the realm of metabolic disease. Additionally, an association between NAFLD and brain aging has been proposed. Therefore, we investigated the hypothesis if NAFLD is an independent risk factor for emerging dementia. In this population-based cohort study, elderly patients (≥ 65 years) with NAFLD diagnosed between 2000 and 2015 were matched 1:1 to a cohort without NAFLD based on ICD-10 coding in the Disease Analyzer database. Matching criteria were age, sex, physician, index year, and co-diagnoses associated with dementia. The primary outcomes of this study were all-cause dementia diagnoses, the incidence of vascular dementia, and antidementive drug prescription. A total of 22,317 patients with NAFLD were matched to 22,317 patients without NAFLD. Within 10 years of the index date, 16.0% of patients with NAFLD and 15.6% of the patients without NAFLD were diagnosed with dementia. On Cox regression analysis, there is no association between NAFLD and the incidence of all-cause dementia (HR 0.97, 95% CI 0.92–1.04), vascular dementia (HR 0.89, 95% CI 0.78–1.02), or the new prescription of antidementive therapy (HR 0.87, 95% CI 0.76–1.01). In sensitivity analyses, there was no association between NAFLD and dementia in different age-groups as well as men or women. In conclusion, in this database study of elderly patients coded with NAFLD no independent association with incident dementia was detected. Risk assessment regarding dementia in patients with NAFLD should be carried out in the same way as for metabolic burdened patients

    Lehren und Lernen mit dem Smarten Physiklabor

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    In diesem Beitrag wird ein neues Aufgabendesign vorgestellt, welches die klassischen Übungsaufgaben in der Einführungsvorlesung 'Experimentalphysik 1 - Mechanik' ergänzt. Zusätzlich zu den wöchentlich ausgegebenen Übungsaufgaben müssen die Studierenden experimentelle Problemstellungen lösen. Durch dieses neue Aufgabenformat erhoffen wir uns eine deutliche Verbesserung des konzeptuellen Verständnisses und der physikalischen Problemlösekompetenz der Lernenden.  In den Experimentieraufgaben dient das Smartphone zeitgleich als Experimentiermedium und Messgerät. Wir präsentieren die Integration solcher smartphonebasierten Experimentierhausaufgaben in den regulären Vorlesungsbetrieb. Des Weiteren wird ein exemplarisches Beispiel einer solchen Aufgabe vorgestellt. Den Abschluss bildet das Feedback unserer Studierenden sowie erste empirische Ergebnisse dieses Lehr-Lern-Projekts

    Lehren und Lernen mit dem Smarten Physiklabor

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    In diesem Beitrag wird ein neues Aufgabendesign vorgestellt, welches die klassischen Übungsaufgaben in der Einführungsvorlesung 'Experimentalphysik 1 - Mechanik' ergänzt. Zusätzlich zu den wöchentlich ausgegebenen Übungsaufgaben müssen die Studierenden experimentelle Problemstellungen lösen. Durch dieses neue Aufgabenformat erhoffen wir uns eine deutliche Verbesserung des konzeptuellen Verständnisses und der physikalischen Problemlösekompetenz der Lernenden.  In den Experimentieraufgaben dient das Smartphone zeitgleich als Experimentiermedium und Messgerät. Wir präsentieren die Integration solcher smartphonebasierten Experimentierhausaufgaben in den regulären Vorlesungsbetrieb. Des Weiteren wird ein exemplarisches Beispiel einer solchen Aufgabe vorgestellt. Den Abschluss bildet das Feedback unserer Studierenden sowie erste empirische Ergebnisse dieses Lehr-Lern-Projekts

    Development of a High-Throughput Screening Assay Based on the 3-Dimensional Pannus Model for Rheumatoid Arthritis

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    Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.The 3-dimensional (3-D) pannus model for rheumatoid arthritis (RA) is based on the interactive co-culture of cartilage and synovial fibroblasts (SFs). Besides the investigation of the pathogenesis of RA, it can be used to analyze the active profiles of antirheumatic pharmaceuticals and other bioactive substances under in vitro conditions. For a potential application in the industrial drug-screening process as a transitional step between 2-dimensional (2-D) cell-based assays and in vivo animal studies, the pannus model was developed into an in vitro high-throughput screening (HTS) assay. Using the CyBi™-Disk workstation for parallel liquid handling, the main cell culture steps of cell seeding and cultivation were automated. Chondrocytes were isolated from articular cartilage and seeded directly into 96-well microplates in high-density pellets to ensure formation of cartilage-specific extracellular matrix (ECM). Cell seeding was performed automatically and manually to compare both processes regarding accuracy, reproducibility, consistency, and handling time. For automated cultivation of the chondrocyte pellet cultures, a sequential program was developed using the CyBio Control software to minimize shear forces and handling time. After 14 days of cultivation, the pannus model was completed by coating the cartilage pellets with a layer of human SFs. The effects due to automation in comparison to manual handling were analyzed by optical analysis of the pellets, histological and immunohistochemical staining, and real-time PCR. Automation of this in vitro model was successfully achieved and resulted in an improved quality of the generated pannus cultures by enhancing the formation of cartilage-specific ECM. In addition, automated cell seeding and media exchange increased the efficiency due to a reduction of labor intensity and handling time. (Journal of Biomolecular Screening 2007:956-965)BMBF, 0313604A, Verbundprojekt: Evaluierung eines interagierenden 3D Testsystems als Krankheitsmodell der rheumatoiden Arthritis (in vitro Pannus Modell) zur effektiven Prüfung von Wirkstoffen, Teilprojekt 1BMBF, 0313604B, Verbundprojekt: Entwicklung eines interagierenden 3D Testsystems als Krankheitsmodell der rheumatoiden Arthritis (in vitro Pannus Modell) zur effektiven Prüfung von Wirkstoffen, Teilprojekt

    Vulnerability Analysis of a Soft Core Processor through Fine-grain Power Profiling

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    Embedded microprocessors are an important component of reconfigurable architectures. Fine-grain (e.g., cycle-accurate) power analysis of such processors has been used to improve power and energy efficiency, and detect implementation vulnerabilities, in embedded applications. However, such analysis is difficult to conduct; it requires either specialized and often expensive equipment, or construction of test architectures using disparate acquisition and analysis tools. In this research, we expand the Flexible Open-source workBench fOr Side-channel analysis (FOBOS) to facilitate exact time-domain correlation of clock cycle and device state to power measurements, and to perform power analysis on a soft core processor. We first validate the fine-grain power analysis capabilities of FOBOS through cycle-accurate analysis of power consumption of AES encryption running on a soft core processor in the Spartan-6 FPGA. We then analyze the results in the context of Simple Power Analysis side-channel attacks, and confirm power correlation of certain instructions with Hamming Weight or Hamming Distance of secret key bytes. Finally, we show that an assumption of a pure Hamming Distance power model for load-to-register instructions is not sufficient for this embedded processor architecture, and that power models using both Hamming Distance and Hamming Weight should be considered for Differential Power Analysis

    Treatment of posttraumatic and focal osteoarthritic cartilage defects of the knee with autologous polymer-based three-dimensional chondrocyte grafts: 2-year clinical results

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    Autologous chondrocyte implantation (ACI) is an effective clinical procedure for the regeneration of articular cartilage defects. BioSeed®-C is a second-generation ACI tissue engineering cartilage graft that is based on autologous chondrocytes embedded in a three-dimensional bioresorbable two-component gel-polymer scaffold. In the present prospective study, we evaluated the short-term to mid-term efficacy of BioSeed-C for the arthrotomic and arthroscopic treatment of posttraumatic and degenerative cartilage defects in a group of patients suffering from chronic posttraumatic and/or degenerative cartilage lesions of the knee. Clinical outcome was assessed in 40 patients with a 2-year clinical follow-up before implantation and at 3, 6, 12, and 24 months after implantation by using the modified Cincinnati Knee Rating System, the Lysholm score, the Knee injury and Osteoarthritis Outcome Score, and the current health assessment form (SF-36) of the International Knee Documentation Committee, as well as histological analysis of second-look biopsies. Significant improvement (p < 0.05) in the evaluated scores was observed at 1 and/or 2 years after implantation of BioSeed-C, and histological staining of the biopsies showed good integration of the graft and formation of a cartilaginous repair tissue. The Knee injury and Osteoarthritis Outcome Score showed significant improvement in the subclasses pain, other symptoms, and knee-related quality of life 2 years after implantation of BioSeed-C in focal osteoarthritic defects. The results suggest that implanting BioSeed-C is an effective treatment option for the regeneration of posttraumatic and/or osteoarthritic defects of the knee

    Higher scores in the Clinical Frailty Scale are associated with covert and overt hepatic encephalopathy in patients with cirrhosis

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    Background: Frailty increases the vulnerability to internal and external stressors and may therefore be an indicator of a higher frequency of cirrhosis complications. We aimed to investigate the association of the Clinical Frailty Scale (CFS) with covert (CHE) and overt HE (OHE) development in patients with cirrhosis. Methods: This study analyzed data of 228 patients with cirrhosis. Frailty was assessed using CFS. Patients were examined for the presence of CHE (using PHES) at study inclusion and followed for OHE. Results: Median CFS was 3 and 26 (11 %) patients were at least pre-frail (CFS>3). In multivariable logistic regression analysis in patients without a history of OHE (n = 195), a higher CFS was associated with the presence of CHE at baseline (OR 1.6, p = 0.039). During follow-up, 42 (18 %) patients developed an episode of OHE. In multivariable competing risk regression analyses, a higher CFS was independently associated with the development of an OHE episode in the total cohort (sHR 1.97, p < 0.001) and in the subcohort of patients without a history of OHE (sHR 1.88, p = 0.008). Conclusion: CFS appears to be a reliable tool to identify patients at higher risk of HE in whom intensified monitoring and treatment may be justified
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