73 research outputs found

    Quiescent consistency: Defining and verifying relaxed linearizability

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    Concurrent data structures like stacks, sets or queues need to be highly optimized to provide large degrees of parallelism with reduced contention. Linearizability, a key consistency condition for concurrent objects, sometimes limits the potential for optimization. Hence algorithm designers have started to build concurrent data structures that are not linearizable but only satisfy relaxed consistency requirements. In this paper, we study quiescent consistency as proposed by Shavit and Herlihy, which is one such relaxed condition. More precisely, we give the first formal definition of quiescent consistency, investigate its relationship with linearizability, and provide a proof technique for it based on (coupled) simulations. We demonstrate our proof technique by verifying quiescent consistency of a (non-linearizable) FIFO queue built using a diffraction tree. © 2014 Springer International Publishing Switzerland

    Digital light processing stereolithography of hydroxyapatite scaffolds with bone-like architecture, permeability, and mechanical properties

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    This work deals with the additive manufacturing and characterization of hydroxyapatite scaffolds mimicking the trabecular architecture of cancellous bone. A novel approach was proposed relying on stereolithographic technology, which builds foam-like ceramic scaffolds by using three-dimensional (3D) micro-tomographic reconstructions of polymeric sponges as virtual templates for the manufacturing process. The layer-by-layer fabrication process involves the selective polymerization of a photocurable resin in which hydroxyapatite particles are homogeneously dispersed. Irradiation is performed by a dynamic mask that projects blue light onto the slurry. After sintering, highly-porous hydroxyapatite scaffolds (total porosity ~0.80, pore size 100-800 µm) replicating the 3D open-cell architecture of the polymeric template as well as spongy bone were obtained. Intrinsic permeability of scaffolds was determined by measuring laminar airflow alternating pressure wave drops and was found to be within 0.75-1.74 × 10−9m2, which is comparable to the range of human cancellous bone. Compressive tests were also carried out in order to determine the strength (~1.60 MPa), elastic modulus (~513 MPa) and Weibull modulus (m = 2.2) of the scaffolds. Overall, the fabrication strategy used to print hydroxyapatite scaffolds (tomographic imaging combined with digital mirror device [DMD]-based stereolithography) shows great promise for the development of porous bioceramics with bone-like architecture and mass transport properties

    An Empirical Study on Collaborative Architecture Decision Making in Software Teams

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    Architecture decision making is considered one of the most challenging cognitive tasks in software development. The objective of this study is to explore the state of the practice of architecture decision making in software teams, including the role of the architect and the associated challenges. An exploratory case study was conducted in a large software company in Europe and fifteen software architects were interviewed as the primary method of data collection. The results reveal that the majority of software teams make architecture decisions collaboratively. Especially, the consultative decision- making style is preferred as it helps to make decisions efficiently while taking the opinions of the team members into consideration. It is observed that most of the software architects maintain a close relationship with the software teams. Several organisational, process and human related challenges and their impact on architecture decision-making are also identified

    Heavy Metal Ions Cu (II), Co (II) and Cr (III) Bifunctionally Improved with Hydroxamic and Amidoxime Groups Chelating Ion Exchangers

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    Two new types of bifunctional chelating ion exchangers on the basis of ethylacrylate acrylonitrile: divinylbenzene copolymers with hydroxamic acid and amidoxime groups have been evaluated for Cu(II), Co(II) and Cr(III)ions sorption from unbuffered diluted aqueous solutions. To model the retention and to compare the sorption capacity of bifunctional acrylic chelating sorbents for the tested cations the Langmuir and Freundlich isotherm equations have been used. The Langmuir maximum sorption capacities for the sorbent of type A were determined to be 2.081, 1.423 and 1.384 mmole/g for Cu (II), Co (II) and Cr (III), respectively. The increase of cross- linking degree for the bifunctional chelating ion exchanger of type B resulted in the decrease of its sorption capacity toward heavy metal ions under study. The negative values of ΔG in all cases point to the spontaneous character of the sorption process. The kinetics of the Cu (II), Co (II) and Cr (III) sorption follows the Lagergren pseudo – first order model. The results are significant for the future development of the tested sorbents into beneficial materials for industrial and environmental applications

    Эффективность озонотерапии в сочетании со стабильной стенокардией путем оценки велоэргометрических проб у пожилых больных

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    Discipline Occupational Diseases, Department of Internal Medicine No 6, Nicolae Testemitanu State Medical and Pharmaceutical University, Congresul III al Medicilor de Familie din Republica Moldova 17–18 mai, 2012, Chişinău, Republica MoldovaThe aim of this study was to assess the clinical efficacy and tolerance of ozone therapy with bicycle stress test in patients of older age groups with coronary artery disease and stable angina. The study included 36 patients with ischemic disease, including 20 men and 16 women, between the ages of 61-70 (mean 64.6 ± 4.8 years). It was proven that the use of ozone therapy in treatment of patients with coronary artery disease could improve the standard antianginal therapy, which manifests an increase in exercise tolerance, decreasing the frequency of anginal attacks, and, as a consequence, decreasing the number of nitroglycerin tablets taken. Была исследована клиническая эффективность комплексного лечения озоном у пациентов со стабильной стенокардией старших возрастных групп. В исследование было включено 36 больных с ишемической болезнью сердца, включая 20 мужчин и 16 женщин, в возрасте 61-70 лет (в среднем 64,6 ± 4,8 года). Было доказано, что использование озонотерапии в лечении пациентов с ишемической болезнью сердца улучшило стандартную терапию, которая проявлялась уменьшением частоты болевых приступов стенокардии и, как следствие, уменьшением приема таблеток нитроглицерина

    Перекисное окисление липидов и ферментные антиоксиданты при неспецифическом язвенном колите

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    Increased oxidative stress has been previously demonstrated in patients with inflammatory bowel disease. But this phenomenon has not been analyzed in the course of ulcerative colitis (UC). In this study we evaluated levels of malondialdehyde (the main product of lipid peroxidation), superoxide dismutase and catalase erythrocyte activities in 62 patients with active UC, in 22 patients after achievement of complete, endoscopic remission and in 52 control subjects. Significant increase of malondialdehyde in patients with active disease in comparison with control subjects, demonstrated in this study, suggests the presence of enhanced oxidative stress in active UC. Activation of enzymatic antioxidant system is characteristic of active UC, which is confirmed by an increase in superoxide dismutase and catalase erythrocyte activities in patients with active disease in comparison with control group. There is no significant difference in malondialdehyde and catalase erythrocyte activity between patients in remission of UC and the control subjects. The increase of conditional adaptive index in patients with active UC confirms large adaptive possibilities of enzymatic antioxidant system. The normal levels of malondialdehyde and catalase can be proposed as markers of complete disease remission in UC.В ряде научных исследований доказано наличие оксидативного стресса при неспецифическом язвенном колите (НЯК). Однако, этот феномен не был изучен в динамике заболевания. В настоящей работе оцениваются уровни малонового диальдегида (основного продукта перекисного окисления липидов), супероксиддисмутазной и каталазной активности эритроцитов у 62-х больных в период обострения НЯК, у 22-х больных после достижения полной, эндоскопической ремиссии и у 52-х человек из группы контроля. Существенное увеличение концентрации малонового диальдегида у пациентов в период обострения заболевания по сравнению с контрольной группой, выявленное в данном исследовании, указывает на наличие выраженного оксидативного стресса при активном НЯК. Для обострения НЯК характерна активация ферментной антиоксидантной системы, что подтверждается значительным увеличением супероксиддисмутазной и каталазной активности эритроцитов у пациентов с активными формами заболевания по сравнению с контрольной группой. Статистически значимых различий уровней малонового диальдегида и каталазной активности не было выявлено между группой контроля и пациентами в период ремиссии. В период обострения заболевания установлено увеличение условного адаптационного индекса, что свидетельствует о широких адаптивных возможностях ферментной антиоксидантной системы. Нормальные уровни малонового диальдегида и каталазы могут быть рекомендованы как маркеры полной ремиссии заболевания при НЯК

    Level of Retinol Deposit and Cervical Cancer

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    Objective: To analyze level of retinol deposit sufficiency in the natural history of cervical cancer. Methods: Serum retinol level was measured by ELISA from peripheral blood of subjects with normal cervix, cleared and persistent high risk human papilloma virus (HR-HPV) subclinical infection, and cervical cancer who fulfilled the inclusion and exclusion criteria. The study was held in Dr. Cipto Mangunkusumo and Fatmawati Hospital, Jakarta, within 2 years (August 2013- 2015). Blood was taken twice, consisting of post-8-hour fasting blood and 2 hours after 6000 IU retinyl palmitate oral administration. Results: Of 47 total samples, sufficient level of retinol deposit in normal cervix, cleared and persistent HR-HPV subclinical infection, and cervical cancer group was 85.0% (reference), 75.0% (OR 1.89), 33.3% (OR 11.33), and 75% (OR 1.89); respectively. Statistically, there was no significant difference from sufficiency level of retinol deposit between normal cervix and clearance HR-HPV subclinical infection (p=0.628), normal cervix and persistent HR-HPV subclinical infection (p=0.078), normal cervix and cervical cancer (p=0.433), cervical cancer and clearance HR-HPV subclinical infection (p=1.000), cervical cancer and persistent HR-HPV subclinical infection (p=0.430), persistent and clearance HR-HPV subclinical infection group (p=0.740). Conclusion: This study proves that normal cervix group has the highest level of retinol deposit sufficiency; however, it cannot be stated that cervical cancer group has less sufficiency level. Persistent HR-HPV subclinical infection group has the lowest level of retinol deposit (OR 11.33). There is no association between sufficient level of retinol deposit and clearance of HR-HPV. [Indones J Obstet Gynecol 2017; 5-1: 46-54] Keywords: cervical cancer, HR-HPV clearance, retinol deposi

    Оценка противовирусной терапии у больных с циррозом печени вирусной этиологии C и D

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    Summary: Study group: 49 patients, 17 (34.69%) women and 32 (65.31%) men with hepatic viral cirrhosis, Child-Pugh stage A: 24 – D viral etiology and 25 – viral C genesis. Average age: 44.41 ± 0.4 years in women and 47.59 ± 0.6 years in men. Purpose: evaluation of the antiviral treatment response at 12 weeks and 24 weeks after initiation and assessment of laboratory results during antiviral therapy in patients with liver cirrhosis C and D. In patients with liver cirrhosis HDV, treated with Peg-INF undetectable viral load was achieved at 12 weeks in 28% cases and after 24 weeks of treatment it is observed in 25% of cases. In the group of patients with liver cirrhosis HCV, treated with Peg-INF + Ribabirină – 12 weeks of treatment – 75% of patients responded positively: 48% achieved complete EVR and 24% – EVR part. Evaluation of patients at 24 weeks of treatment show a positive virologic response in 56% cases. In patients with liver cirrhosis HCV and HDV, where the virological response was absent, more severe, and early complications of antiviral therapy are observed: the blood count shows anemia, major leukopenia and thrombocytopenia.Pезюме: Группа исследования: 49 пациентов, 17 (34,69%) женщин и 32 (65,31%) мужчин с циррозом печени вирусной этиологии, стадия Child-Pugh А: 24 – вирусной этиологии D и 25 – вирусной этиологии C. Средний возраст: 44,41 ± 0,4 лет у женщин и 47,59 ± 0,6 лет у мужчин. Цель: оценка ответа на противовирусное лечение на 12-ой неделе и на 24-ой неделе после начала лечения и оценка лабораторных показателей во время противовирусной терапии у больных с циррозом печени С или D. У пациентов с циррозом печени HDV, леченных Peg-INF, была достигнута авиремия на 12-ой неделе в 28% случаев и на 24-ой неделе лечения – в 25% случаев. В группе пациентов с циррозом печени вирусной этиологии С, леченных Peg-INF + рибавирин, наблюдается на 12-ой неделе лечения положительный ответ у 75% пациентов: у 48% достигнут полный ранний вирусологический ответ, у 24% – частичный. Оценка противовирусного лечения через 24 недели после начала показала положительный вирусологический ответ в 56% случаев. У пациентов с циррозом печени вирусной этиологии С или D с отсутствием вирусологического ответа на противирусную терапию обнаруживаются осложнения более тяжелые и раньше: в анализе крови – анемия, лейкопения и тромбоцитопения

    A practical and user-friendly toxicity classification system with microbiotests for natural waters and wastewaters

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    Various types of toxicity classification systems have been elaborated by scientists in different countries, with the aim of attributing a hazard score to polluted environments or toxic waste-waters or of ranking them in accordance with increasing levels of toxicity. All these systems are based on batteries of standard acute toxicity tests (several of them including chronic assays as well) and are therefore dependent on the culturing and maintenance of live stocks of test organisms. Most systems require performance of the bioassays; on dilution series of the original samples, for subsequent calculation of L(E C50 or threshold toxicity values. Given the complexity and costs of these toxicity measurements, they can only be applied in well-equipped and highly specialized laboratories, and none of the classification methods so far has found general acceptance at the international level. The development of microbiotests that are independent of continuous culturing of live organisms has stimulated international collaboration. Coordinated at Ghent University, Belgium, collaboration by research groups from 10 countries in central and eastern Europe resulted in an alternative toxicity classification system that was easier to apply and substantially more cost effective than any of the earlier methods. This new system was developed and applied in the framework of a cooperation agreement between the Flemish community in Belgium and central and eastern Europe. The toxicity classification system is based on a battery of (culture-independent) microbiotests and is particularly suited for routine monitoring. It indeed only requires testing on undiluted samples of natural waters or wastewaters discharged into the aquatic environment, except for wastewaters that demonstrate more than 50% effect. The scoring system ranks the waters or wastewaters in 5 classes of increasing hazard/toxicity, with calculation of a weight factor for the concerned hazard/toxicity class. The new classification system was applied during 2000 by the participating laboratories on samples of river water, groundwaters, drinking waters, mine waters, sediment pore waters, industrial effluents, soil leachates, and waste dump leachates and was found to be easy to apply and reliable. © 2003 Wiley Periodicals, Inc
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