211 research outputs found
Pavement structural evaluation using the Rolling Wheel Deflectometer
The Rolling Wheel Deflectometer (RWD) offers the benefit to measure pavement deflection without causing any traffic interruption or compromising safety along the tested road segments. This study describes a detailed field evaluation of the RWD system in Louisiana in which 16 different test sites representing a wide array of pavement conditions were tested. Measurements were used to assess the repeatability of RWD measurements, to examine the effect of truck speeds, and to study the relationship between RWD and FWD deflection measurements and pavement conditions. Based on the results of the experimental program, it was determined that the repeatability of RWD measurements was acceptable with an average coefficient of variation at all test speeds of 15%. In addition, the influence of the testing speed on the measured deflections was minimal. The scattering and uniformity of the FWD and RWD data appear to follow closely the conditions of the roadway. Both test methods appear to properly reflect pavement conditions and structural integrity of the road network by providing for a greater average deflection and scattering for sites in poor conditions. RWD deflection measurements were in general agreement with FWD deflections measurements; however, the mean center deflections from RWD and FWD were statistically different for 15 of the 16 sites. This study also developed and validated a direct and simple model for determining the pavement Structural Number (SN) using RWD deflection data. To develop this model, the relationship between the average RWD surface deflection and the peak FWD deflection was investigated. The developed model correlates pavement SN to two RWD-measured properties (average RWD deflection and RWD Index). The developed model was fitted to RWD data collected in 16 road-sections (each 1.5 miles), referred to as research sites, in Louisiana. The model was then validated based on FWD and RWD data collected on 52 road sections in Louisiana. Results showed a good agreement between SN calculations obtained from FWD and RWD deflection testing. While the developed model is independent of the pavement thickness and layer properties, it provides promising results as an indicator of structural integrity of the pavement structure at the network level. The fitting statistics support the use of the proposed model as a screening tool for identifying structurally-deficient pavements at the network level
Inter-observer agreement of the Coronary Artery Disease Reporting and Data System (CAD-RADS^{TM}) in patients with stable chest pain
Purpose: To assess inter-observer variability of the Coronary Artery Disease - Reporting and Data System (CAD-RADS) for classifying the degree of coronary artery stenosis in patients with stable chest pain. Material and methods: A prospective study was conducted upon 96 patients with coronary artery disease, who underwent coronary computed tomography angiography (CTA). The images were classified using the CAD-RAD system according to the degree of stenosis, the presence of a modifier: graft (G), stent (S), vulnerable plaque (V), or non-diagnostic (n) and the associated coronary anomalies, and non-coronary cardiac and extra-cardiac findings. Image analysis was performed by two reviewers. Inter-observer agreement was assessed. Results: There was excellent inter-observer agreement for CAD-RADS (k = 0.862), at 88.5%. There was excellent agreement for CAD-RADS 0 (k = 1.0), CAD-RADS 1 (k = 0.92), CAD-RADS 3 (k = 0.808), CAD-RADS 4 (k = 0.826), and CAD-RADS 5 (k = 0.833) and good agreement for CAD-RADS 2 (k = 0.76). There was excellent agreement for modifier G (k = 1.0) and modifier S (k = 1.0), good agreement for modifier N (k = 0.79), and moderate agreement for modifier V (k = 0.59). There was excellent agreement for associated coronary artery anomalies (k = 0.845), non-coronary cardiac findings (k = 0.857), and extra-cardiac findings (k = 0.81). Conclusions: There is inter-observer agreement of CAD-RADS in categorising the degree of coronary arteries stenosis, and the modifier of the system and associated cardiac and extra-cardiac findings
ARE OPTIMISTS HAPPIER AND MORE SATISFIED WITH THEIR LIFE?هل المتفائلون أكثر سعادة ورضا عن حياتهم؟
استهدفت هذه الدراسة استكشاف العلاقة بين التفاؤل وكل من السعادة، والرضا عن الحياة، فضلاً عن فحص العلاقة بين التشاؤم والسعادة، والرضا عن الحياة. أجابت عينة متاحة (ن = 225) من طلبة جامعة الإسكندرية وطالباتها عن: القائمة العربية للتفاؤل والتشاؤم، ومقياسي التقدير الذاتي لكل من السعادة، والرضا عن الحياة، ولم تكشف النتائج عن فروق دالة إحصائيًا بين الجنسين في كل متغيرات الدراسة، في حين استخرجت ارتباطات دالة إحصائيًا بين التفاؤل وكل من السعادة، والرضا عن الحياة (موجبة)، وبين التشاؤم وكل من السعادة، والرضا عن الحياة (سالبة). وكشف تحليل المكونات الأساسية عن عامل ثنائي القطب لدى الجنسين، سمي: الحياة الطيبة في مقابل التشاؤم . وخلصت هذه الدراسة، إلى أن التفاؤل أحد المتغيرات المهة في الحياة النفسية الطيبة، وهو الموضوع الأساسي في علم النفس الإيجابي
Kinetics and Mechanism of Oxidation of Co (II) Ternary Complexes Involving N-(2-Acetamido) Iminodiacete and Some Amino Acids Acid by Periodate
The kinetics of oxidation of the cobalt (II) complexes, [CoII(ADA)(Gly)(H2O)2]-, (ADA = N-(2-acetamido) iminodi-acetic acid and (Gly = Glycine) by periodate in aqueous acetate medium to cobalt (III) have been studied spectrophotometrically at 530 nm over the 30–50°C and a variety pH 4.57-5.25 range and I = 0.50 mol dm-3 under pseudo first order condition by taking large excess of oxidant [IO4-] and it obeys the following rate law: Rate=[CoII(ADA)(Gly)(H2O)2]-[H5IO6]{k4K6+(k5K7K5/[H+])}. Also, the kinetics of oxidation of the cobalt(II) complexes, [CoII(ADA)(Val)(H2O)2]- (ADA = N-(2-acetamido) iminodi-acetic acid and (Val = valine) by periodate in aqueous medium to cobalt (III) have been studied spectrophotometrically at 580 nm over the 30–50°C and a variety pH 4.3-5.12 range and I = 0.50 mol dm-3 under pseudo first order condition by taking large excess of oxidant [IO4-] and it obeys the following rate law: Rate=[CoII(ADA)(Val)(H2O)2]-[H5IO6]{k4K6+(k5K7K5/[H+])
Kinetics and Mechanism of Oxidation of Co (II) Ternary Complexes Involving N-(2-Acetamido) Iminodiacete and Some Amino Acids Acid by Periodate
The kinetics of oxidation of the cobalt (II) complexes, [CoII(ADA)(Gly)(H2O)2]-, (ADA = N-(2-acetamido) iminodi-acetic acid and (Gly = Glycine) by periodate in aqueous acetate medium to cobalt (III) have been studied spectrophotometrically at 530 nm over the 30–50°C and a variety pH 4.57-5.25 range and I = 0.50 mol dm-3 under pseudo first order condition by taking large excess of oxidant [IO4-] and it obeys the following rate law: Rate=[CoII(ADA)(Gly)(H2O)2]-[H5IO6]{k4K6+(k5K7K5/[H+])}. Also, the kinetics of oxidation of the cobalt(II) complexes, [CoII(ADA)(Val)(H2O)2]- (ADA = N-(2-acetamido) iminodi-acetic acid and (Val = valine) by periodate in aqueous medium to cobalt (III) have been studied spectrophotometrically at 580 nm over the 30–50°C and a variety pH 4.3-5.12 range and I = 0.50 mol dm-3 under pseudo first order condition by taking large excess of oxidant [IO4-] and it obeys the following rate law: Rate=[CoII(ADA)(Val)(H2O)2]-[H5IO6]{k4K6+(k5K7K5/[H+])
Inter-observer agreement of whole-body computed tomography in staging and response assessment in lymphoma : the lugano classification
Background: to assess inter-observer agreement of whole-body computed tomography (WBCT) in staging and response assessment in lymphoma according to the Lugano classification. Material/Methods: Retrospective analysis was conducted of 115 consecutive patients with lymphomas (45 females, 70 males; mean age of 46 years). Patients underwent WBCT with a 64 multi-detector CT device for staging and response assessment after a complete course of chemotherapy. Image analysis was performed by 2 reviewers according to the Lugano classification for staging and response assessment. Results: The overall inter-observer agreement of WBCT in staging of lymphoma was excellent (k=0.90, percent agreement=94.9%). There was an excellent inter-observer agreement for stage I (k=0.93, percent agreement=96.4%), stage II (k=0.90, percent agreement=94.8%), stage III (k=0.89, percent agreement=94.6%) and stage IV (k=0.88, percent agreement=94%). The overall inter-observer agreement in response assessment after a completer course of treatment was excellent (k=0.91, percent agreement=95.8%). There was an excellent inter-observer agreement in progressive disease (k=0.94, percent agreement=97.1%), stable disease (k=0.90, percent agreement=95%), partial response (k=0.96, percent agreement=98.1%) and complete response (k=0.87, Percent agreement=93.3%). Conclusions: We concluded that WBCT is a reliable and reproducible imaging modality for staging and treatment assessment in lymphoma according to the Lugano classification
Functional Results Following Treatment of Vestibular Schwannomas: Comparative Study between Surgery and Radiation
Objective:
Treatment of vestibular Schwannomas, represent a matter of strong controversy, and to date no class I evidence can support the benefit of certain treatment modality over the others. Expectant treatment, microsurgery, and gamma knife radiosurgery represent the most important options to be considered. The main goal of the present study is to compare the functional outcome after gamma knife and surgical treatment in the long-term follow up.
Patients and Methods:
269 patients submitted to microsurgery and 427 patients treated with gamma knife in two different centers were followed up for 16.4 ± 13.6 months and 42.4 ± 26.8 months respectively. Tumor volumetry based on serial MR images, facial nerve function according to the House-Brackman scale, hearing function according to the Gardner-Robertson scale, tinnitus, trigeminal symptoms, and dizziness were systematically analyzed and compared between both treatment modalities.
Results:
Based on the normalized volumetry over time, surgery was more efficient than gamma knife on tumor control. While functional results regarding facial nerve and hearing preservation favored radiosurgery over surgery especially in large VS, the results were comparable in cases of smaller tumors (Class T1, T2 and T3). There was a relative advantage of surgery over radiosurgery for tinnitus, dizziness and facial hypoesthesia.
Conclusion:
Our results represent a further contribution to the field and offer evidence-based criteria to support the indication of one treatment modality according to patients’ expectations and professional activity.Ziel: Die Therapie von Vestibularisschwannomen gliedert sich weitestgehend in drei Teilbereiche: Mikrochirurgische Resektion des Tumors, strahlentherapeutische Behandlung oder sog. „Wait-Scan-Strategie“ womit eine Verlaufsbeobachtung des Tumorwachtums in festgelegten Intervallen gemeint ist. Eine evidenz-basierte Entscheidungshilfe im Sinne von Evidenz-Klasse-1 Studien, existiert in der medizinischen Literatur bis heute nicht. Das Hauptziel der vorliegenden Studie ist es daher, die funktionellen langfristigen Ergebnisse der strahlentherapeutischen Behandlung mit dem Gamma-Knife und der mikrochirurgische Behandlung zu vergleichen.
Patienten und Methoden: Die retrospektive Analyse der vorgelegten Studie beinhaltet 269 Patienten in der mikrochirurgische Gruppe und 427 Patienten in der radiochirurgischen Gruppe, mit medianen Beobachtungszeiträumen von 16.4 ± 13.6 Monaten in der mikrochirurgischen Gruppe und 42.4 ± 26.8 Monaten in der radiochirurgischen Gruppe. Auswertung und statistische Evaluation von prä-therapeutischen Tumorvolumen (Hannover-Klassifikation) und deren Veränderung im Behandlungsverlauf, N. Fazialis-Funktion anhand der House-Brackman-Skala, Hörfunktion anhand der Gardner-Robertson-Skala, Beurteilung eines persistierenden Tinnitus, Störungen der Sensibilität im Gesicht (N.trigeminus Affektion), sowie persistierende Schwindel-Symtomatik wurden restrospektiv analysiert.
Ergebnisse: Es zeigte sich im Langzeitsverlauf der Tumorvolumetriebestimmung besser Ergebnisse nach mikrochirurgischer Behandlung. Die radiochirurgische Behandlung war bezogen auf den funktionellen Erhalt der N. fazialis sowie des Erhalt des auditorischen Systems insbesondere bei grösseren Tumoren der mikrochirurgischen Resektion űberlegen, jedoch gilt dies nicht fűr kleine Tumore (Klasse T1, T2 und T3). Post-therapeutischer Tinnitus, Schwindelsymptomatik, sowie Beinträchtigung der N. trigeminus Funktion zeigten mit mikrochirurgischer Behandlung bessere Endergebnisse.
Schlussfolgerungen: Die Ergebnisse der vorgelegten Studie stellen einen weiteren nűtzlichen evidenz-basierten Beitrag zur Wahl der geeigneten Behandlungsmethode bei Patienten mit Vestibularisschwannomen dar
Direct foreign investment, transnational corporations and the transfer of technology to Egypt
The main concern of this thesis is to assess the performance of the transnational corporations in the transfer of technology to Egypt. The thesis first, reviews the economic literature concerning the economic rationale behind the phenomenon of direct foreign investment and its effect on transnationals' performance in host developing countries. It surveys the debate on the transfer of technology to developing countries and the major issues that arise and then looks at the development of the industrialisation process in Egypt from 1952 to 1974, the date that marks the adoption of the Open Door Economic Policy. The magnitude of foreign investment is assessed by sector and industry and the domestic policy context which might affect the outcome of the transfer of technology is discussed in some detail. The main part of this thesis reports the results of a survey undertaken in Egypt on the contribution of the transnational corporations to the transfer of technology. It was found that the finms surveyed have not engaged in a genuine transfer of technology. The transnationals were found to be keen to transfer mostly unadapted technology from their own home countries or other advanced markets. Accordingly, no genuine effort has been made in fields such as research and development, training of local personnel and co-operation with local research and development institutes. Moreover, these firms were found to concentrate on products with a high import content. In the meantime, their record of exports from Egypt has proved to be very poor. These conclusions are mostly consonant with what has been argued by the critical literature and dissonant with the conventional view of the transnationals' impact on developing countries with regard to both direct foreign investment and the transfer of technology
Magnetic resonance spectroscopy of the frontal region in patients with metabolic syndrome : correlation with anthropometric measurement
Purpose: to demonstrate 1H-MR spectroscopy of the frontal region in patients with metabolic syndrome and to correlate the metabolic ratios with anthropometric measurement. Material and methods: A prospective study was conducted upon 20 patients with metabolic syndrome (10 male, 10 female; mean age 52 years) and 20 age- and sex-matched volunteers. Patients were mild-moderate (n = 14) and marked and morbid obesity (n = 6). Patients and volunteers underwent 1H-MR spectroscopy of the frontal region. The Ch/Cr and NAA/Cr ratio were calculated and correlated with anthropometric measurement. Results: The Cho/Cr and NAA/Cr of patients with Mets (1.03 ± 0.08 and 1.62 ± 0.08) were significantly different (p = 0.001) to those of volunteers (0.78 ± 0 and 1.71 ± 0.61, respectively). The Cho/Cr and NAA/Cr cutoffs used to differentiate patients from volunteers were 0.89 and 1.77 with areas under the curve of 0.992 and 0.867 and accuracy of 97% and 93%, respectively. There was a significant difference in Cho/Cr and NAA/Cr between patients with marked-morbid obesity and moderate-mild obesity (p = 0.001 respectively). Conclusions: We concluded that NAA/Cr and Cho/Cr ratios of the frontal region can differentiate patients with metabolic syndrome from volunteers and are well correlated with the anthropometric measurement
Computed tomography assessment of hepatic metastases of breast cancer with revised response evaluation criteria in solid tumors (RECIST) criteria (version 1.1) : inter-observer agreement
Background: To assess inter-observer agreement of revised RECIST criteria (version 1.1) for computed tomography assessment of hepatic metastases of breast cancer. Material/Methods: A prospective study was conducted in 28 female patients with breast cancer and with at least one measurable metastatic lesion in the liver that was treated with 3 cycles of anthracycline-based chemotherapy. All patients underwent computed tomography of the abdomen with 64-row multi-detector CT at baseline and after 3 cycles of chemotherapy for response assessment. Image analysis was performed by 2 observers, based on the RECIST criteria (version 1.1). Results: Computed tomography revealed partial response of hepatic metastases in 7 patients (25%) by one observer and in 10 patients (35.7%) by the other observer, with good inter-observer agreement (k=0.75, percent agreement of 89.29%). Stable disease was detected in 19 patients (67.8%) by one observer and in 16 patients (57.1%) by the other observer, with good agreement (k=0.774, percent agreement of 89.29%). Progressive disease was detected in 2 patients (7.2%) by both observers, with perfect agreement (k=1, percent agreement of 100%). The overall inter-observer agreement in the CT-based response assessment of hepatic metastasis between the two observers was good (k=0.793, percent agreement of 89.29%). Conclusions: We concluded that computed tomography is a reliable and reproducible imaging modality for response assessment of hepatic metastases of breast cancer according to the RECIST criteria (version 1.1)
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