17 research outputs found

    Determining Concrete Composition on Recycled Aggregates

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    abstractPL: -abstractEN: The problem of recycling of construction wastes is important and at the same timedifficult to deal with. One of the possible ways of using the construction wastes coming from thedemolition of concrete constructions is to re-use them in the production of construction concretes asrecycled concrete aggregates RCA. Determining the concrete composition with the use of RCAdemands conditioning its different from the natural aggregates NA physical and mechanicalproperties. In the procedure of projecting the concrete composition with three equations theory theassumption of consistency class of concrete mixture is demanded. Having accepted it, the waterdemand of aggregates and cement is determined. In case of natural aggregates NA the formulas ofSterne's and Bolomey's are used in which aggregates water demand is conditioned from its kind andgranulation and also from concrete mixture consistency. In case of RCA, there is lack of such dataand each time it is necessary to determine the water demand empirically after performing a trialbatch. There also exists a necessity to determine the relation between RCA water demand and itsother properties which are easy to be determined in laboratory conditions and in short time. Such aproperty can be measured with the crushing rate wrm resistance of aggregates to crushing. Crushingrate wrm was used to qualify the recycled aggregates from recycling with the point of their potentialof being re-used in constructive concrete production. It was determined a relation between crushingrate wrm and the coefficient ARCA taking place in the modified strength equation of Bolomey and thusit became possible to use the method of three equations to project the concrete composition onrecycled aggregates.score: 8collation: 266-27

    Changes in the Treg lymphocyte population levels in patients being treated for ovarian cancer with chemotherapy

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    Regulatory T lymphocytes CD4+CD25+FOXP3+ or Treg cells play a major role in immune system surveillance and tolerance. Treg cells are critical for controlling the immunological system because they inhibit the cytotoxic response. Moreover, it has been found that Treg cell recruitment into the tumor microenvironment reduces the chances of survival in cancer patients and that an increase in Treg cells in the peripheral blood correlates with the progression of ovarian cancer. In our study we addressed Treg cell population changes in cases of ovarian cancer where the patients were treated with chemotherapy. Using flow cytometry we determined the levels of CD4+CD25+FOXP3+ lymphocytes in the peripheral blood of the patients prior to chemotherapy, after 3 courses of chemotherapy, and then after 6 courses (the respective regimens were: TK 鈥 13, CP 鈥 1, TPT 鈥 1 patient). We observed that the Treg lymphocyte levels of ovarian cancer patients decreased after 3 courses of chemotherapy though the difference (p=0.3) was not statistically significant. After 6 chemotherapy courses, however, levels did increase to a statistically significant degree (p=0.02). We have therefore concluded that a measurement of the Treg cell population could be helpful in estimating the impact of chemotherapy on a patient鈥檚 host immune system during the systemic treatment of ovarian cancer.Limfocyty regulatorowe T CD4+CD25+FOXP3+ (kom贸rki Treg) odgrywaj膮 istotn膮 rol臋 w mechanizmach nadzoru i tolerancji immunologicznej, hamuj膮c odpowied藕 cytotoksyczn膮 uk艂adu odporno艣ciowego. Wykazano, 偶e w trakcie rozwoju choroby nowotworowej liczebno艣膰 limfocyt贸w Treg wzrasta. Obecno艣膰 naciek贸w z limfocyt贸w Treg w mikro艣rodowisku guza wi膮偶e si臋 z gorszym rokowaniem, a wzrost populacji kom贸rek Treg we krwi obwodowej koreluje z progresj膮 raka jajnika. W niniejszym badaniu sprawdzano wp艂yw chemioterapii stosowanej u chorych z rakiem jajnika na liczebno艣膰 populacji Treg we krwi obwodowej. W tym celu odsetek Treg we krwi oznaczano przed, po 3 oraz po 6 kursach chemioterapii (TK 鈥 13, CP 鈥 1, TPT 鈥 1 chora) za pomoc膮 cytometrii przep艂ywowej. Podczas pierwszych 3 cykli chemioterapii zaobserwowano pocz膮tkowe zmniejszenie odsetka limfocyt贸w T CD4+CD25+ FOXP3+ w艣r贸d limfocyt贸w T CD4+, niemniej jednak r贸偶nica ta nie by艂a znamienna statystycznie (p=0,3). Nast臋pnie w miar臋 kontynuowania chemioterapii odsetek limfocyt贸w T CD4+CD25+FOXP3+ w艣r贸d limfocyt贸w T CD4+ wzrasta艂 i po 6. cyklu w stosunku do aktywno艣ci po 3. cyklu chemioterapii by艂 statystycznie znamiennie wi臋kszy (p=0,02). Autorzy wnioskuj膮, 偶e badanie populacji Treg mo偶e by膰 przydatne do oceny wp艂ywu chemioterapii na uk艂ad odporno艣ciowy gospodarza podczas leczenia systemowego chorych na raka jajnika