Degradation research of protective coating on AZ91D Mg alloy components via simulated contamination

Accelerated environmental(hygrothermal)exposure experiments are performed on organic paints coated on commercial die-cast AZ91D Mg alloys to investigate the effects of contamination on blistering.Specifically,artificial human perspiration spray is used to contaminate the substrate surface.Blistering occurred only for paints that are spread on surfaces with the perspiration present.More blisters gradually form at longer test times,and the volume of blistering increases.Scanning electron microscopy indicates that blistering is initiated by contamination and/or substrate corrosion at the interface of the organic paints and the substrate.Blistering is characterized for two samples exposed to the hygrothermal environments for various times,and is found to be initially empty in the early stages.Hydrophilic chloride contaminants from the perspiration lead to in situ adhesion loss.Simultaneously,the paints volume expands,and the associated compressive stress causes it to bulge.After long-term test exposure,chloride anions corrode the substrate under the films,and MgO,Mg(OH)_(2),and Mg_(2)(OH)_(3)Cl corrosion products fill the blisters.Finally,a model of blistering evolution is discussed.

Expression of recombinant human butyrylcholinesterase in the milk of transgenic mice

Butyrylcholinesterase(BCHE)is a natural bioscavenger that protects humans against organophosphate toxicity.Due to the limited yield of human BCHE(hBCHE)when purifying from human plasma,it is necessary to find an alternative method to produce this protein.One potential method is to produce transgenic livestock that make modified milk containing high concentration of hBCHE.In this study,we cloned the hBCHEgene into a human lactoferrin(hLF)bacterial artificial chromosome(BAC)construct to make a hLFhBCHE BAC construct.Subsequently,we injected the BAC construct into pronuclei of mouse fertilized embryos and generated transgenic mice.Expression analysis showed that recombinant hBCHE(rhBCHE)was expressed efficiently in the mammary gland of the transgenic mice and the concentration of rhBCHE in the milk of individual mice ranged from 76
12 to 159
28 mg·L^(–1).Protein function tests showed that rhBCHE has the same enzymatic activity as the native hBCHE.Our results pave the way for making transgenic livestock to produce large quantities of rhBCHE.

Chimera formation of platelet GPⅡb Bak a/b by intrauterine transplantation of fetal liver stem cells

Abstract:Objective To investigate whether artificial heterozygous chimeras of platelets can be established by intrauterine transplantation of fetal liver stem cells and evaluate its potential use for the treatment of Glanzmann thrombasthenia.Methods Platelet glycoprotein (GP) Ⅱb Bak a/b (or GPⅡb Ⅰle843Ser) was used as a genetic marker. A homozygous 16-week-old Bak a/a fetus (as donor) and a homozygous 16.5-week-old Bak b/b fetus (as recipient) were screened from 42 pregnant women hospitalized for abortion. PCR with allele specific primers and FOK Ⅰ digestion based on PCR products were used. Aborted donor fetal liver cell suspensions were prepared and intrauterine transplantation was carried out by infusion of 4?ml fetal liver cells (22×105) into the recipient umbilical vein under ultrasonic visualization.Results At gestation termination (abortion), 21 days after transplantation, chimera GPⅡb Bak a/b of the recipient were detected by FOK 1 digestion based on PCR from DNA and RT-PCR from platelet RNA. Conclusion Intrauterine transplantation of fetal liver cell may provide an effective way for curing GT or other inherited diseases.

Crowd intelligence in AI 2.0 era

The Internet based cyber-physical world has profoundly changed the information environment for the development of artificial intelligence(AI), bringing a new wave of AI research and promoting it into the new era of AI 2.0. As one of the most prominent characteristics of research in AI 2.0 era, crowd intelligence has attracted much attention from both industry and research communities. Specifically, crowd intelligence provides a novel problem-solving paradigm through gathering the intelligence of crowds to address challenges. In particular, due to the rapid development of the sharing economy, crowd intelligence not only becomes a new approach to solving scientific challenges, but has also been integrated into all kinds of application scenarios in daily life, e.g., online-tooffline(O2O) application, real-time traffic monitoring, and logistics management. In this paper, we survey existing studies of crowd intelligence. First, we describe the concept of crowd intelligence, and explain its relationship to the existing related concepts, e.g., crowdsourcing and human computation. Then, we introduce four categories of representative crowd intelligence platforms. We summarize three core research problems and the state-of-the-art techniques of crowd intelligence. Finally, we discuss promising future research directions of crowd intelligence.