Seismic vulnerability analysis of traditional brick-wood buildings with cracks

The evaluation of seismic vulnerability of traditional brick-wood buildings is hindered by the presence of cracks in their walls. The purpose of this study is to explore the influence of wall cracks on the vulnerability of traditional brick-wood buildings, with a specific focus on Zhang Fang's former residence in Kaifeng City as a representative case. The dynamic characteristics of the structure are analyzed by ambient vibration test. The stress analysis under static loading and the vulnerability analysis under different seismic waves are carried out for the finite element method (FEM) models with and without cracks to evaluate the failure probability of structure under damage state. The results show that the dynamic response characteristics of the FEM model with cracks are closer to the results of ambient vibration test than that of the FEM model without cracks. From the time-history analysis results, the acceleration and displacement of the structure are mainly transmitted and diffused along the longitudinal direction under seismic waves. With the increase of seismic intensity, the structural acceleration amplification factor tends to increase and then decrease, and the inter-story drift angle tends to increase. Compared the vulnerability analysis results of models with cracks to that of models without cracks, the failure probabilities of FEM model with cracks under different seismic intensity are higher. Consequently, it is crucial to consider wall cracks in numerical simulations of traditional brick-wood buildings in order to ensure more accurate results for seismic vulnerability analysis

Pb2+ biosorption from aqueous solutions by live and dead biosorbents of the hydrocarbon-degrading strain Rhodococcus sp. HX-2.

In this study, the Pb2+ biosorption potential of live and dead biosorbents of the hydrocarbon-degrading strain Rhodococcus sp. HX-2 was analyzed. Optimal biosorption conditions were determined via single factor optimization, which were as follows: temperature, 25°C; pH, 5.0, and biosorbent dose, 0.75 g L-1. A response surface software (Design Expert 10.0) was used to analyze optimal biosorption conditions. The biosorption data for live and dead biosorbents were suitable for the Freundlich model at a Pb2+ concentration of 200 mg L-1. At this same concentration, the maximum biosorption capacity was 88.74 mg g-1 (0.428 mmol g-1) for live biosorbents and 125.5 mg g-1 (0.606 mmol g-1) for dead biosorbents. Moreover, in comparison with the pseudo-first-order model, the pseudo-second-order model seemed better to depict the biosorption process. Dead biosorbents seemed to have lower binding strength than live biosorbents, showing a higher desorption capacity at pH 1.0. The order of influence of competitive metal ions on Pb2+ adsorption was Cu2+ > Cd2+ > Ni+. Fourier-transform infrared spectroscopy analyses revealed that several functional groups were involved in the biosorption process of dead biosorbents. Scanning electron microscopy showed that Pb2+ attached to the surface of dead biosorbents more readily than on the surface of live biosorbents, whereas transmission electron microscopy confirmed the transfer of biosorbed Pb2+ into the cells in the case of both live and dead biosorbents. It can thus be concluded that dead biosorbents are better than live biosorbents for Pb2+ biosorption, and they can accordingly be used for wastewater treatment

Morphological characteristics of 21-d-old seedlings of WT and transgenic maize.

<p>The data point are the mean of two independent biological experiments, and each experiment comprised five samples. Error bars denote the standard deviation values.</p

A redox-responsive self-assembling COA-4-arm PEG prodrug nanosystem for dual drug delivery suppresses cancer metastasis and drug resistance by downregulating hsp90 expression

Metastasis and resistance are main causes to affect the outcome of the current anticancer therapies. Heat shock protein 90 (Hsp90) as an ATP-dependent molecular chaperone takes important role in the tumor metastasis and resistance. Targeting Hsp90 and downregulating its expression show promising in inhibiting tumor metastasis and resistance. In this study, a redox-responsive dual-drug nanocarrier was constructed for the effective delivery of a commonly used chemotherapeutic drug PTX, and a COA-modified 4-arm PEG polymer (4PSC) was synthesized. COA, an active component in oleanolic acid that exerts strong antitumor activity by downregulating Hsp90 expression, was used as a structural and functional element to endow 4PSC with redox responsiveness and Hsp90 inhibitory activity. Our results showed that 4PSC/PTX nanomicelles efficiently delivered PTX and COA to tumor locations without inducing systemic toxicity. By blocking the Hsp90 signaling pathway, 4PSC significantly enhanced the antitumor effect of PTX, inhibiting tumor proliferation and invasiveness as well as chemotherapy-induced resistance in vitro. Remarkable results were further confirmed in vivo with two preclinical tumor models. These findings demonstrate that the COA-modified 4PSC drug delivery nanosystem provides a potential platform for enhancing the efficacy of chemotherapies

Schematic structure of the T-DNA and molecular analysis of <i>LOS5</i>-expressing maize.

<p>(A) T-DNA region of the vector pCAMBIA1300-<i>LOS5</i>. LB, left T-DNA border; RB, right T-DNA border; pSuper, ‘Super-Promoter’; Hygromycin, hygromycin phosphotransferase II gene; CaMV, cauliflower mosaic virus 35S promoter. (B) PCR analysis using two <i>LOS5</i>-specific primers to identify four independent T4 transgenic lines. (C) Northern analyses of T4 transgenic maize (lines M-6 and M-8) under well-watered and drought stress conditions. Moderate drought stress (D1) was applied to 21-d-old maize by maintaining 60% normal water supply for 5 d, whereas the control plants were watered normally. Total RNAs were isolated from uppermost fully expanded leaves of WT and transgenic maize and used for northern blotting. (D) Expression of <i>LOS5</i> under 20% PEG. Expression of <i>LOS5</i> was determined by RT-qPCR using RNAs isolated from 21-d-old WT and transgenic maize (lines M-6 and M-8) exposed to 20% PEG for 12 h. <i>Actin</i> gene was used as the control. Expression level of transgenic line was shown relative to the expression of transgenic line grown under well-watered condition. Error bars denote the standard deviation values, and asterisks indicated a significant difference (*<i>P</i><0.05) compared with the corresponding controls.</p

Leaf water status assay.

<p>Changes in leaf water potential (A) and relative water content (B) in WT and transgenic maize (lines M-6 and M-8) subjected to drought stress. Drought stress treatment was imposed as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052126#pone-0052126-g002" target="_blank">Fig. 2 (A)</a> above. Error bars denote the standard deviation values, and asterisks indicate a significant difference (*<i>P</i><0.05) compared with the corresponding controls.</p

Drought-stress-tolerant phenotype, water loss and stomatal assay.

<p>(A) Drought-stress-tolerant phenotype of transgenic maize (lines M-6 and M-8). Drought stress treatment was applied to 21-d-old seedlings of WT and transgenic maize by completely withholding irrigation for 10 d, then re-watering for 2 d. 21 d, 21-d-old seedling; D 2 d, completely withholding irrigation for 2 d; D 5 d, completely withholding irrigation for 5 d; D 10 d, completely withholding irrigation for 10 d; R 2 d, re-watered for 2 d. (B) Survival rates of transgenic maize plants overexpressing <i>LOS5</i> under drought-stress conditions. Fifty 21-d-old seedling from each lines or WT were deprived of water for 14 d, watering was resumed for 7 d, and then the plants were scored for viability. Plants were considered dead if all the leaves were brown and there was no growth after 7 d of watering. Each column represents an average of two independent experiments with three replicates, and values represented the mean ±SD. (C) Comparison of transpirational water loss in detached leaves of WT and transgenic maize. Values represent the mean ±SD (n = 4). (D) Comparison of stomatal apertures of WT and transgenic maize under drought stress conditions. Drought stress treatment was imposed as described in Fig. 2 (A) above. Error bars denote the standard deviation values, and asterisks indicated a significant difference (*<i>P</i><0.05) compared with the corresponding controls.</p

RT-qPCR analysis of stress-responsive genes.

<p>RNA levels of <i>Rad 17</i> (A), <i>NECD1</i> (B), <i>CAT1</i> (C), and <i>ZmP5CS1</i> (D) genes were determined by RT-qPCR using RNAs isolated from 21-d-old WT and transgenic maize (lines M-6 and M-8) exposed to 20% PEG. <i>Actin</i> gene was used as the control. The expression level of transgenic lines is shown relative to the expression of WT plants grown under well-watered condition. Error bars denote the standard deviation values, and asterisks indicate a significant difference (*<i>P</i><0.05; ** <i>P</i><0.01) compared with the corresponding controls.</p