153 research outputs found

    Quality of life in dialysis versus kidney transplantation

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    Introduction: The compromised health-related quality of life (HRQOL) of patient with end-stage renal disease(ESRD) is now well documented. One of the main pointswhen treating patients with ESRD, whose cure is not arealistic goal, is maximizing functioning and well-being,which refer to the ability to perform various dailyactivities and functions and to more subjective internalstates such as symptoms and feelings.Aim: Is to study the difference in QOL between dialysispatients and living renal transplant recipients using SF-36 Health survey and factors affecting QOL.Setting and participant: Seventy patients were includedin our study 34 of them were males and 36 females. Theywere divided into 3groups: Group Ia: 30 hemodialysispatients of at least 6 months duration on dialysis, GroupIb: 10 continuous ambulatory peritoneal dialysis (CAPD)and Group II: 30 recipients of living renal transplants of? 6 months duration. SF-36 questionnaire was filled byall patients; it includes eight subscales which can also becombined into two component summary scores, Aphysical component summary PCS {general heath (GH),physical function (PF), role-physical (RP), bodily pain(BP)} and a mental component summary MCS {roleemotional(RE), vitality (VT), mental health (MH), andsocial function (MH)}. Data were analyzed from thisquestionnaire to determine the QOL for all patients andwere correlated also with clinical and laboratoryparameters.Results: Among hemodialysis patients, PCS, PF and VTparameters were better in young subjects and MH waspositively correlated with the hemoglobin level. Patientswithout co-morbid conditions had significantly betterQOL in PF and RP parameters. QOL was significantlybetter in employed than unemployed persons regardingPF, RP, VT, SF, GH and PCS. As regard CAPD patients without co-morbid conditions had significantly better QOL than those with co-morbid condition regarding RP, GH, SF and PCS. Among recipients of renal transplantation, there was a significant positive correlation between hemoglobin level and QOL parameters PCS, MCS, VT, SF and MH and a significant negative correlation between age of transplanted recipients and PF and VT was recorded. Finally in comparison of the three studied groups there was significant difference between the studied groups as regard PF parameter of SF-36 health survey which was higher in transplanted group than HD and CAPD.Conclusion: In hemodialysis patients the best quality of life was to males young aged with high hemoglobin level and no co-morbid conditions. In CAPD the best quality of life was to young aged and no co-morbid conditions. In renal transplant the best quality of life was to young age and high hemoglobin level. Finally there was no difference in QOL with three forms of renal replacement therapy

    Authentication enhancement in command and control networks: (a study in Vehicular Ad-Hoc Networks)

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    Intelligent transportation systems contribute to improved traffic safety by facilitating real time communication between vehicles. By using wireless channels for communication, vehicular networks are susceptible to a wide range of attacks, such as impersonation, modification, and replay. In this context, securing data exchange between intercommunicating terminals, e.g., vehicle-to-everything (V2X) communication, constitutes a technological challenge that needs to be addressed. Hence, message authentication is crucial to safeguard vehicular ad-hoc networks (VANETs) from malicious attacks. The current state-of-the-art for authentication in VANETs relies on conventional cryptographic primitives, introducing significant computation and communication overheads. In this challenging scenario, physical (PHY)-layer authentication has gained popularity, which involves leveraging the inherent characteristics of wireless channels and the hardware imperfections to discriminate between wireless devices. However, PHY-layerbased authentication cannot be an alternative to crypto-based methods as the initial legitimacy detection must be conducted using cryptographic methods to extract the communicating terminal secret features. Nevertheless, it can be a promising complementary solution for the reauthentication problem in VANETs, introducing what is known as “cross-layer authentication.” This thesis focuses on designing efficient cross-layer authentication schemes for VANETs, reducing the communication and computation overheads associated with transmitting and verifying a crypto-based signature for each transmission. The following provides an overview of the proposed methodologies employed in various contributions presented in this thesis. 1. The first cross-layer authentication scheme: A four-step process represents this approach: initial crypto-based authentication, shared key extraction, re-authentication via a PHY challenge-response algorithm, and adaptive adjustments based on channel conditions. Simulation results validate its efficacy, especially in low signal-to-noise ratio (SNR) scenarios while proving its resilience against active and passive attacks. 2. The second cross-layer authentication scheme: Leveraging the spatially and temporally correlated wireless channel features, this scheme extracts high entropy shared keys that can be used to create dynamic PHY-layer signatures for authentication. A 3-Dimensional (3D) scattering Doppler emulator is designed to investigate the scheme’s performance at different speeds of a moving vehicle and SNRs. Theoretical and hardware implementation analyses prove the scheme’s capability to support high detection probability for an acceptable false alarm value ≤ 0.1 at SNR ≥ 0 dB and speed ≤ 45 m/s. 3. The third proposal: Reconfigurable intelligent surfaces (RIS) integration for improved authentication: Focusing on enhancing PHY-layer re-authentication, this proposal explores integrating RIS technology to improve SNR directed at designated vehicles. Theoretical analysis and practical implementation of the proposed scheme are conducted using a 1-bit RIS, consisting of 64 × 64 reflective units. Experimental results show a significant improvement in the Pd, increasing from 0.82 to 0.96 at SNR = − 6 dB for multicarrier communications. 4. The fourth proposal: RIS-enhanced vehicular communication security: Tailored for challenging SNR in non-line-of-sight (NLoS) scenarios, this proposal optimises key extraction and defends against denial-of-service (DoS) attacks through selective signal strengthening. Hardware implementation studies prove its effectiveness, showcasing improved key extraction performance and resilience against potential threats. 5. The fifth cross-layer authentication scheme: Integrating PKI-based initial legitimacy detection and blockchain-based reconciliation techniques, this scheme ensures secure data exchange. Rigorous security analyses and performance evaluations using network simulators and computation metrics showcase its effectiveness, ensuring its resistance against common attacks and time efficiency in message verification. 6. The final proposal: Group key distribution: Employing smart contract-based blockchain technology alongside PKI-based authentication, this proposal distributes group session keys securely. Its lightweight symmetric key cryptography-based method maintains privacy in VANETs, validated via Ethereum’s main network (MainNet) and comprehensive computation and communication evaluations. The analysis shows that the proposed methods yield a noteworthy reduction, approximately ranging from 70% to 99%, in both computation and communication overheads, as compared to the conventional approaches. This reduction pertains to the verification and transmission of 1000 messages in total

    Study of Lateral Load Influence on Behaviour of Negative Skin Friction on Circular and Square Piles

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    Negative skin friction developed on the pile surface causes many problems when piles are built in fully saturated clay. In this work, a study of NSF on a square cross-section pile corresponding to the circular pile circumference was developed. The pile was modeled as a concrete element, embedded and fully contacted with fully saturated soft clay. The clay layer is supported on a sand layer as a sub-base using ABAQUS software, and the NSF was developed on piles due to the consolidation of the clay over a 5-year period. A square pile has been found to provide lower NSF values than a round pile. Then, for the first investigation, both piles were loaded with lateral loads at the top to investigate the effect of the horizontal load on the NSF values, as there is no literature or study done on this point. The results emphasized that lateral loads reduce the NSF developed on piles. A parametric study was performed to investigate the parameters affecting the NSF values induced on piles, such as soil permeability, ballast, and lateral load values. It was concluded that square piles provide better NSF values than round piles for both single piles and pile groups. Doi: 10.28991/CEJ-2022-08-10-08 Full Text: PD

    Quality of Context Enhancements and Cost Effective Radio over Fiber Network Planning

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    The In-hospital prognostic value of high sensitivity C-reactive protein in STEMI patients treated by thrombolysis versus primary

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    Introduction: Coronary artery disease (CAD) is considered a major causative agent of mortality and morbidity. Many reports recommended the use of C-reactive protein (CRP) as an inflammatory marker for its high sensitivity that could help in prevention of CAD.Objective: This work aimed to clarify the in-hospital prognostic value of high-sensitivity CRP (hs-CRP) in ST-elevation myocardial infarction (STEMI) cases who are treated by thrombolysis vs. primary percutaneous coronary intervention (PCI) and comparing the outcome of the treatment between the two groups.Patients and methods: 48 STEMI cases were divided into two groups in this cross-section study: Patients in group A had Primary PCI, whereas those in group B received thrombolysis treatment. Patients were evaluated by history, examinations, investigations and coronary angiography.Results: Most of patients had grade II mitral regurge (68.8%) with statistical insignificant differences between the study groups. Most of patients had wall motion abnormalities in anterior septum (43.8%) with statistical insignificant difference between groups. In this study, 41.7% of patients had positive troponin with statistical insignificant difference between groups. According to distribution of patients as regards outcomes, died patient and patients with heart failure had significantly higher median of first- and second-hour CRP than patients without adverse eventsConclusion: Impaired reperfusion was correlated with higher hs-CRP compared to optimal reperfusion. This study was conducted on CRP so further investigation with larger population size are necessary especially for inflammatory cascade

    Study of amino acid disorders among a high risk group of Egyptian infants and children

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    Aim of the work: The present work aimed at investigating infants (In neonatal and post neonatal period) and children suspected of having inborn errors of metabolism with unexplained mental retardation. The frequency pattern of the various amino acid disorders, in a group of selected infants and children was done to document the prevalence of various amino acid disorders among Egyptian children. Patients and Method: In this study, recent methods to investigate such disorders have been carried out by amino acid analyzer which detects levels of amino acids. Extended metabolic screen which also detects amino acid disorders, organic acid disorders and the defects of fatty acid oxidation has been carried out. These recent methods have therefore the potential of yielding information on the physiological and pathophysiological status of different metabolic pathways, as well as their interrelationship. Results: The total number of cases attending the outpatient clinic during the period of study were 1343 index cases, among them 50 index cases (3.72%) were suspected of having inborn errors of amino acid and, 20 cases (40%) of them have confirmed positive inborn errors of amino acid metabolism. Concerning the confirmed 20 cases, their ages ranged from 5 days to 11 years with a mean of 54.75±33.09 months with equally sex distribution. The overall consanguinity rate recorded was 65%, while the family history of the similarly affected cases was 30%. The main clinical findings included mental retardation 85%, convulsions 40%, and hypo pigmentation 75%, micro-cephally 15%. Associated anomalies were present in 35% of cases. Among them eye anomalies were the most common (8%). Conclusion: The prevalence of amino-acido-pathies during the period of the study was 1.5% (Of 20 studied cases), among them PKU was found to be the commonest amino-acido-pathies 1.11%, while the remaining diagnosed cases representing 0.07% for each. Keywords: Amino acid disorders, high risk, children Egypt. J. Hum. Genet Vol. 8 (2) 2007: pp. 173-19

    The Effect of Mineral Pigments on Mechanical Properties of Concrete

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     Pigmented concrete exhibits artesian properties in addition to ordinary concrete properties, explicitly high strength, excellent durability, and weather resistance. However, the influence of several parameters that affect the characteristics of colored concrete should be studied; extensively. In this paper, the impact of the w/b (water/binder) ratio using color pigments on the mechanical properties such as compressive and flexural strengths of colored cement mortar prisms and cubes experimentally investigated. The experimental program included 21 mixes with six cubes and three flexural prisms specimens for assessing compressive and flexural strength, respectively. The blends included different water/binder ratios with values of 0.4, 0.5, and 0.6, in addition to several color pigments as a partial replacement of cement. The percentage of replacements altered between 0, 2.5%, 5% and 7.5% with two different shades of pigments consisting of red iron and green chromium oxide. Based on the experimental results, empirical expressions were generated based on Abram’s law to assess the relationship between the compressive strength of colored concrete and w/b ratio. The results revealed that the compressive and flexural strength of colored concrete is influenced by w/b ratio and partially replacement percentage of cement by color pigment not proportionally direct. Furthermore, the shade of pigments also has a different impact as well

    Impact of occult hepatitis B virus infection on antiviral therapy in chronic hepatitis C patients

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    Background: Occult HBV infection (OBI) can be defined by the presence of HBV-DNA in the serum of patients who are negative for HBsAg. The presence of OBI has been associated with a poor therapeutic response to alpha IFN in many, but not in all studies.Objective: The aim of our study was to assess the prevalence of OBI in the serum of Egyptian patients with CHC, and to evaluate its impact on the response to treatment with a combination of Peg-IFNa and RBV.Materials and methods: Fifty chronic HCV infected patients who were treated with Peg-IFNa once a week in combination with RBV for 48 weeks were included in this study. Patients were divided into two groups, group I which included 25 patients who achieved SVR and group II that included 25 patients who failed to achieve SVR (Non-SVR). Both patient groups were subjected to detailed questionnaire, clinical examination, routine laboratory investigations and virological studies.Results: No statistical significant difference was found in sex distribution regarding SVR and Non-SVR. The frequency of patients with low viral load has a statistically significant association.KEYWORDS: Chronic hepatitis C; Occult HBV infection; Sustained virological respons

    Efficient blockchain-based group key distribution for secure authentication in VANETs

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    This paper proposes a group key distribution scheme using smart contract-based blockchain technology. The smart contract’s functions allow for securely distributing the group session key, following the initial legitimacy detection using public key infrastructure-based authentication. For message authentication, we propose a lightweight symmetric key cryptography-based group signature method, supporting the security and privacy requirements of vehicular ad hoc networks (VANETs). Our discussion examined the scheme’s robustness against typical adversarial attacks. To evaluate the gas costs associated with smart contract’s functions, we implemented it on the Ethereum main network. Finally, comprehensive analyses of computation and communication costs demonstrate the scheme’s effectiveness

    Scanning electron microscopic study of the effect of chlorpyrifos on the developing neural tube in comparison with Arsenic in mouse embryo

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    Background: Arsenic is an important environmental toxicant which is usually found in drinking water in inorganic form. Arsenic exposure in pregnant mice causes neural tube defects (NTDs). Chlorpyrifos, an organophosphorus insecticide, recommended universally and in Egypt to control various pests, was evaluated for its potential developmental toxicity. Studies have shown increasing evidence to suggest an association between environmental exposure to this agricultural pesticides and adverse reproductive outcomes. The hypothesis tested in this investigation is chlorpyrifos causes significant defects on the developing central nervous system compared to the proven Arsenic.Objectives: The aim of this work was to assess congenital malformations induced by the organophosphorus insecticide chlorpyrifos on the neural tube and brain development in comparison with the positive control Arsenic.Methods: Virgin female ICR (CD-1) mice, approximately 10 weeks old were mated with adult males. The day the vaginal plug was found was considered day 0 of gestation. It consisted of 320 mice. They were subdivided into four groups of 80 bred mice each. Each group was divided into 4 subgroups, and 20 mice per each were treated by gavage as follows: 30 mg/kg/day chlorpyrifos (tested group), 40 mg/kg/day sodium Arsenite (positive control group), and corn oil and distilled water (negative control groups) on days 6–15 of gestation. Maternal observations throughout gestation were reported. In each subgroup the mice proved to be pregnant were sacrificed on gestational days; GD 10, 11, 12 and 16. The day of scarification was determined according to the neural tube developmental stages. The conceptus extraction was done and their number reported to be subjected to the SEM study. After mice scarification, the uteri were opened and a total of 30 embryos and fetuses, randomly selected from each subgroup were processed for scanning electron microscopy investigating the neural tube developmental defects.Results: CPF ingested by gravid mice at dose of 30 mg/kg/day started from 6th day of gestation proved to produce NTDs as compared to Arsenite.Conclusion: Neural tube defects are due to chlorpyrifos that may directly influence brain cell replication and differentiation
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