149 research outputs found
A Novel Buffer Tank to Attenuate the Peak Flow of Runoff
Impermeable pavements and roofs in urban areas convert most rainfall to runoff, which is commonly discharged to local sewers pipes and finally to the nearby streams and rivers. In case of heavy rain, the peak flow of runoff usually exceeds the carrying capacity of the local sewer pipes, leading to urban flooding. Traditional facilities, such as green roofs, permeable pavements, soakaways, rainwater tanks, rain barrels, and others reduce the runoff volume in case of a small rain but fail in case of a heavy rain. Here we propose a novel rainwater buffer tank to detain runoff from the nearby sealed surfaces in case of heavy rain and then to discharge rainwater from an orifice at the tankβs bottom. We found that considering a 100m2 rooftop with 0.80 runoff coefficient and a 10cm rainfall depth for an hour, a cubic tank with internal edge side of a square of 2 m attenuates the peak flow about 45%. To reduce a desirable peak flow, the outlet orifice of the buffer tank must be optimized according to site-specific conditions. The orifice can be set at an elevation from the tankβs bottom to create a dead storage for harvesting rainwater
Facile fabrication of lightweight porous FDM-printed polyethylene/graphene nanocomposites with enhanced interfacial strength for electromagnetic interference shielding
In order to shield the massive electromagnetic perturbations and meet the more and more stringent requirement for advanced electronic equipment, development of diverse, lightweight and high-performance electromagnetic interference (EMI) shielding materials is urgent but still challenging. Herein, the facile and green method which combines fused deposition modeling (FDM) 3D printing, ball milling and microwave (MW) irradiation technology was proposed to fabricate exfoliated graphene nanoplatelets (GNPs) incorporated liner low density polyethylene (LLDPE) nanocomposite lightweight parts with porous and complex geometry structure. FDM 3D printing possesses high flexibility for structure design, which can significantly broaden the application of materials in various fields. Benefiting from design of a unique porous lamellar structure, the printed LLDPE/GNPs nanocomposite parts can achieve a prominent EMI shielding effectiveness (SE) of ~32.4 dB (with thickness-normalized specific EMI SE (SSE/t) of 318 dB cm2/g) in the range of 8.2β12.4 GHz. This remarkable characteristic is due to internal multiple reflections and absorption of electromagnetic (EM) waves. In addition, the specific FDM 3D-printed porous parts prepared by our strategy exhibit a relatively higher EMI SE at a lower density than those lightweight EMI shields in literatures. The use of MW irradiation technology improves mechanical properties, especially for the interfacial bonding strength between filaments. More importantly, this strategy is highly favorable for the fabrication of lightweight porous EMI shields with tailorable and optimized shape/structure, which could be expected to be applied in aerospace fields, portable electronic devices, smart devices and so on
HSP60, a protein downregulated by IGFBP7 in colorectal carcinoma
<p>Abstract</p> <p>Background</p> <p>In our previous study, it was well defined that <it>IGFBP7 </it>was an important tumor suppressor gene in colorectal cancer (CRC). We aimed to uncover the downstream molecules responsible for <it>IGFBP7</it>'s behaviour in this study.</p> <p>Methods</p> <p>Differentially expressed protein profiles between PcDNA3.1(<it>IGFBP7</it>)-transfected RKO cells and the empty vector transfected controls were generated by two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) identification. The selected differentially expressed protein induced by IGFBP7 was confirmed by western blot and ELISA. The biological behaviour of the protein was explored by cell growth assay and colony formation assay.</p> <p>Results</p> <p>Six unique proteins were found differentially expressed in PcDNA3.1(<it>IGFBP7</it>)-transfected RKO cells, including albumin (ALB), 60 kDa heat shock protein(HSP60), Actin cytoplasmic 1 or 2, pyruvate kinase muscle 2(PKM2), beta subunit of phenylalanyl-tRNA synthetase(FARSB) and hypothetical protein. The downregulation of HSP60 by IGFBP7 was confirmed by western blot and ELISA. Recombinant human HSP60 protein could increase the proliferation rate and the colony formation ability of PcDNA3.1(<it>IGFBP7</it>)-RKO cells.</p> <p>Conclusion</p> <p>HSP60 was an important downstream molecule of IGFBP7. The downregulation of HSP60 induced by IGFBP7 may be, at least in part, responsible for IGFBP7's tumor suppressive biological behaviour in CRC.</p
Hepatotoxicity induced by zoledronic acid in an aged woman with primary osteoporosis
Zoledronic acid, a bisphosphonate, has been approved for treatment and prevention of osteoporosis. This case describes a 73-year-old woman with primary osteoporosis who developed transient hepatotoxicity after zoledronic acid (ZOL) treatment. Three days after ZOL infusion, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma-glutamyltransferase (GGT) were increased by 9.9, 8.1, and 3.7 times, respectively, compared with pretreatment values. Liver protective agents were administered. The aminotransferase returned within normal ranges 12 days post-infusion. Currently, the relationship of ZOL and liver damage is not quite clear, which cannot be explained by its pharmacokinetics. The aim of this
case report is to increase the clinicianβs awareness of the possible adverse effect on the liver, and ZOL should be cautiously administered in patients with liver disease
Psoralen-loaded lipid-polymer hybrid nanoparticles enhance doxorubicin efficacy in multidrug-resistant HepG2 cells
Background: Psoralen (PSO), a major active component of Psoralea corylifolia, has been shown to overcome multidrug resistance in cancer. A drug carrier comprising a lipid-monolayer shell and a biodegradable polymer core for sustained delivery and improved efficacy of drug have exhibited great potential in efficient treatment of cancers. Methods: The PSO-loaded lipid polymer hybrid nanoparticles were prepared and characterized. In vitro cytotoxicity assay, cellular uptake, cell cycle analysis, detection of ROS level and mitochondrial membrane potential (ΞΞ¨m) and western blot were performed. Results: The P-LPNs enhanced the cytotoxicity of doxorubicin (DOX) 17-fold compared to free DOX in multidrug resistant HepG2/ADR cells. Moreover, P-LPNs displayed pro-apoptotic activity, increased levels of ROS and depolarization of ΞΞ¨m. In addition, there were no significant
effects on cellular uptake of DOX, cell cycle arrest, or the expression of P-glycoprotein. Mechanistic studies suggested that P-LPNs enhanced DOX cytotoxicity by increased release of cytochrome c and enhanced caspase3 cleavage, causing apoptosis in HepG2/ADR cells. Conclusion: The lipid-polymer hybrid nanoparticles can be considered a powerful and promising
drug delivery system for effective cancer chemotherapy. Keywords: lipid-polymer hybrid nanoparticles, psoralen, drug delivery, HepG2, ADR cells,
apoptosis.This work was supported by the National Natural Science Foundation of China (81273707), the Ministry of Education in the New Century Excellent Talents (NECT-12-0677), the Natural Science Foundation of Guangdong (S2013010012880,
2016A030311037), the Science and Technology Program of Guangzhou (2014J4500005, 201704030141), the Science Program of the Department of Education of Guangdong (2013KJCX0021, 2015KGJHZ012), the Science and Technology Program of Guangdong (2015A050502027), and the Special Project of International Scientific and Technological Cooperation in Guangzhou Development District (2017GH16)
Ambient volatile organic compounds in a suburban site between Beijing and Tianjin : Concentration levels, source apportionment and health risk assessment
Volatile organic compounds (VOCs) have vital implications for secondary pollutants, atmospheric oxidation and human health. Ambient VOCs were investigated using an online system, gas chromatography-mass spectrometry/flame ionization detector (GC-MS/FID), at a suburban site in Xianghe in the North China Plain from 6 November 2017 to 29 January 2018. Positive matrix factorization (PMF) receptor model was applied to identify the major VOC contributing sources. Four-step health risk assessment method was used to estimate risks of all risk-posing VOC species. A total of 101 VOCs were quantified, and the mean concentration of total VOCs was 61.04 +/- 65.18 ppbv. The VOCs were dominated by alkanes (38.76%), followed by alkenes, aromatics, halocarbons, OVOCs, acetylene and acetonitrile. The results of PMF revealed that vehicle exhaust, industrial emissions, liquefied petroleum gas & natural gas, solvent utilization and secondary and long-lived species contributed 31.0%, 26.4%, 18.6%, 13.6% and 10.4%, respectively, to the total VOCs. Pollutant-specific and source-specific non-carcinogenic and carcinogenic risk estimates were conducted, which showed that acrolein and vehicle exhaust had evident noncarcinogenic risks of 4.9 and 0.9, respectively. The carcinogenic risks of specific species (1,3-butadiene, acetaldehyde, benzene, chloroformand 1,2-dichloroethane) and identified sources were above the United States Environmental Protection Agency (USEPA) acceptable level (1.0 x 10(-6)) but below the tolerable risk level (1.0 x 10(-4)). Vehicle exhaust was the largest contributor (56.2%) to noncarcinogenic risk, but solvent utilization (32.6%) to carcinogenic risk. Moreover, with the evolution of pollution levels, almost all VOC species, contributions of alkenes, aromatics, solvent utilization and vehicle exhaust, and pollutant-specific and source-specific risks increased continuously and noticeably. Collectively, our findings unraveled the importance of alkenes, aromatics, solvent utilization and vehicle exhaust in the evolution of pollution levels. Future studies should consider targeting these VOC groups and sources when focusing on effective reduction strategies and assessing public health risks. (c) 2019 Elsevier B.V. All rights reserved.Peer reviewe
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