Elaboration and application of mathematical model for estimation of mould contamination of some building materials based on ergosterol content determination

The study presents a mathematical function describing a correlation between the amount of ergosterol and the number of colony-forming units (CFU) of mould contaminating selected building materials such as: a block of cellular concrete, gypsum—carton board and gypsum—carton board covered with emulsion paint. The dependence obtained for a particular material as well as an average dependence for all the investigated materials has been described by means of an exponential equation. It has been found out that there is high, statistically significant correlation between ergosterol content and CFU number of mould in all of the building materials. The correlation coefficients have ranged from r=0.790 to 0.933. The elaborated equation describing the above dependence can be applied to estimate mould contamination by means of culture methods within the range 10³–10⁸ CFU/m² of the surface. In addition, the estimated level of ergosterol in these materials has been shown to be the criterion by which to evaluate the degree of filamentous fungal contamination. It has been assessed that an ergosterol content exceeding the level of 3.96 mg/m² indicates the active development of mould. This criterion has been applied to evaluate several building materials i.e.: concrete, gypsum board, emulsion coatings, brick, plaster, wallpaper, glass wool, mineral wool and wood. No statistically significant differences have been observed between CFU number of mould calculated from a model equation on the basis of the ergosterol content and CFU number of mould experimentally determined by traditional methods. The results presented in this paper show that the elaborated equation of correlation between the ergosterol content and CFU number of mould can be applied to estimate mould contamination of different building materials, based on the determination of ergosterol.     

Different requirements for Ia-bearing accessory cells in mitogen versus antigen induction of human B-cell responses

The accessory cell requirements for the induction of proliferative and specific antibody responses of human lymphocytes stimulated with either antigen or mitogen were examined. An Ia-negative human myeloid tumor cell line, K562, could substitute for monocytes in the proliferation of monocyte-depleted lymphocytes in response to pokeweed mitogen (PWM) stimulation. K562 cells could also act as accessory cells in the PWM-induced anti-keyhole limpet hemocyanin (KLH) antibody synthesis of cells from a KLH-immunized donor. In contrast, only monocytes and not K562 cells could function as accessory cells in antigen-induced lymphocyte proliferation as well as in antigen-induced, antigen-specific antibody production. However, K562 cells, like monocytes, were able to positively and negatively regulate polyclonal immunoglobulin responses. Thus, Ia-bearing accessory cells can function in antigen-induced proliferation and antibody responses while non-Ia-bearing cells can function in mitogen-induced, but not anti-geninduced responses. These studies indicate a dichotomy in the nature of required accessory cells in antigen-induced versus mitogen-induced human lymphocyte responses and strongly suggest an obligatory role of Ia or an Ia-related molecule on accessory cells in antigen-induced responses of human lymphocytes.     

Inhibition by specific monosaccharides of interleukin 2-induced thymocyte proliferation

When rat thymocytes are cultured for 3 days in serum-free medium and are stimulated to divide by interleukin 2 (IL 2), concanavalin A, or sodium periodate oxidation, addition to the medium of 10–25 mMd-ribose, 2-deoxy-d-ribose, or N-acetyl-d-galactosamine inhibits by 40% or more the incorporation of [³H]thymidine. d-ribose and lectin-free IL 2 generated from sodium periodate oxidation of rat spleen cells were used to study the characteristics of this inhibition and to test possible mechanisms of inhibition. Viability of thymocytes cultured with d-ribose is similar to that of cells cultured without this sugar. In order to be inhibitory, d-ribose has to be added to the cultures within the first 24 hr, and the inhibition can be prevented if the sugar is removed 18–24 hr after the start of culture. d-Ribose does not block the absorption of IL 2 by unstimulated rat thymocytes or by concanavalin A-generated thymic or splenic blast cells. When thymocytes are cultured with d-ribose for 24 hr, inactivated with mitomycin C, and then cultured for 3 days with fresh mitogenically stimulated cells, [³H]thymidine incorporation into the latter is not altered. This suggests that the sugar does not generate suppressor cells or suppressor supernates. d-Ribose does not appear to be a general metabolic inhibitor since [³H]leucine incorporation into thymocyte proteins and the release of [³H]leucine into medium after a 2-hr. [³H]leucine pulse are not altered by d-ribose. Trivial or artifactual effects (nonspecific cytotoxicity, changes in thymidine transport, or changes in isotonicity of the culture medium) cannot explain the inhibition. A hypothetical mechanism of inhibition is discussed.     

In vitro growth of murine T cells. IV. Use of T-cell growth factor to clone lymphoid cells

Murine bone marrow cells can suppress the in vitro primary antibody response of normal spleen cells without apparent cytotoxicity. The bone marrow cells suppress the response to both T-dependent (SRBC) and T-independent (DNP-Ficoll) antigens. When bone marrow cells are fractionated on a sucrose density gradient, the suppressive activity is found in the residue rather than the lymphocyte fraction. The suppressive activity is either unaffected or enhanced by treatment with anti-T- and anti-B-cell serums. Pretreatment of mice with phenylhydrazine which reduces the number of pre-B cells did not reduce the suppressive activity of their bone marrow cells. Suppressive activity is abolished by irradiation of the marrow cells in vitro with 1000 R prior to assay. The activity is present in the marrow of thymus deficient (nude) mice, infant mice, and mice which have been made polycythemic by transfusion. Furthermore, the suppressor cell can phagocytize iron carbonyl particles, is slightly adherent to plastic and Sephadex G-10, and can bind to EA monolayers. We conclude that the suppressor cell is not a mature lymphocyte or granulocyte nor a member of the erythrocytic series, but is likely to be an immature cell possibly of the myeloid series. We speculate on the physiologic role of this cell.     

Creatine kinase of heart mitochondria: Changes in its kinetic properties induced by coupling to oxidative phosphorylation

A complete kinetic analysis of the forward mitochondrial creatine kinase reaction was conducted to define the mechanism for its rate enhancement when coupled to oxidative phosphorylation. Two experimental systems were employed. In the first, ATP was produced by oxidative phosphorylation. In the second, heart mitochondria were pretreated with rotenone and oligomycin, and ATP was regenerated by a phosphoenolpyruvate-pyruvate kinase system. Product inhibition studies showed that oxidative phosphorylation did not effect the binding of creatine phosphate to the enzyme. Creatine phosphate interacted competitively with both ATP and creatine, and the E · MgATP · CrP dead-end complex was not readily detected. In a similar manner, the dissociation constants for creatine were not influenced by the source of ATP: K_ib = 29 mm; K_b = 5.3 mM, and the maximum velocity of the reaction was unchanged: V₁ = 1 μmol/ min/mg. Slight differences were noted for the dissociation constant (K_ia) of MgATP from the binary enzyme complex, E · MgATP. The values were 0.75 and 0.29 mm in the absence and presence of respiration. However, a 10-fold decrease in the steady-state dissociation constant (K_a) of MgATP from the ternary complex, E · MgATP · creatine, was documented: 0.15 mm with exogenous ATP and 0.014 mm with oxidative phosphorylation. Since K_ia × K_b does not equal K_a × K_ib under respiring conditions, the enzyme appears to be altered from its normal rapid-equilibrium random binding kinetics to some other mechanism by its coupling to oxidative phosphorylation.     

A framework for evaluating sustainability indicators in the real estate industry

The growth in the use of sustainability indicators and ratings in the real estate industry has been accompanied by strong criticism of the most commonly used rating systems designed to evaluate the sustainability performance of real estate developments. Most of these criticisms focus on the content of the different rating systems. A systematic evaluation of the methodologies of sustainability ratings is lacking. This article builds a framework that can be used to evaluate the methodologies of sustainability ratings and applies the evaluation framework to five widely used sustainability ratings for homes and communities (BREAAM, CASBEE, Estidama, Green Star, LEED). The evaluation results highlight three major shortcomings in the rating systems that have been evaluated. First, the systems lack unambiguous definitions of sustainability. They give insufficient explanation of why certain components are included in the ratings and on what basis these components have been accorded their weights. Second, the rating systems put more emphasis on sustainable design than performance, especially for the ratings for communities. Finally, the ratings are generally not responsive to local conditions of a project. Each rating system has its particular strengths and weaknesses and no system is superior on all dimensions. The proposed evaluation framework can be applied to sustainability ratings in different industries and is adaptable depending on stakeholder requirements.     

通往风景园林行业的BIM之路——数字化竖向设计教育

随着全球建造业向数字化全面转型,建筑信息模型（BIM)的教学将是未来几年风景园林设计与实施的重要主题。介绍了风景园林专业BIM的教学方法和数字化竖向设计及其应用在BIM场地设计项目中的重要性。数字化竖向设计是实现BIM的途径。风景园林教育必须在其教学中讲解BIM建模方法和过程。     

Synthesis and biological evaluation of PSMA-targeting paclitaxel conjugates

Prostate cancer (PC) is the second most commonly occurring cancer in men. Conventional chemotherapy has wide variety of disadvantages such as high systemic toxicity and low selectivity. Targeted drug delivery is a promising approach to decrease side effects of therapy. Prostate specific membrane antigen (PSMA) is overexpressed in prostate cancer cells while low level of expression is observed in normal cells. In this study we describe the development of Glu-urea-Lys based PSMA-targeting conjugates with paclitaxel. A series of new PSMA targeting conjugates with paclitaxel was designed and synthesized. The cytotoxicity of conjugates was evaluated against prostate (LNCaP, 22Rv1 and PC-3) and non-prostate (Hek293T, VA13, A549 and MCF-7) cell lines. The most promising conjugate 21 was examined in vivo using 22Rv1 xenograft mice model. It demonstrated good efficiency comparable with paclitaxel, while reduced toxicity. 3D molecular docking study was also performed to understand underlying mechanism of binding and further optimization of the linker substructure and conjugates structure for improving the target affinity. These conjugates may be useful for further design of novel PSMA targeting delivery systems for PC.