Rapid nanomolar detection of methamphetamine in biofluids via a reagentless electrochemical aptamer-based biosensor.

The availability of sensing platforms able to rapidly measure abused drugs directly in biological fluids in a single step would allow performing drugged driving screening on the site. The achievement of this goal is extremely important for preventing and controlling drug abuse and crime incidence. Motived by this, we constructed a simple, cost-effective and reagentless electrochemical aptamer-based (EAB) sensor with methamphetamine (MAMP) as the target molecule. This EAB sensor produced a nanomolar level of detection accuracy in unprocessed or minimally processed bio-samples. Specifically, circular dichroic spectrum was used to confirm that the truncated aptamer from the original sequence would undergo large binding-induced conformational changes. We then engineered the aptamer to work in the EAB platform and the resulting sensor enabled sensitive and specific detection of MAMP with the detection limit of 30 nM in undiluted serum, 50 nM in undiluted urine and 20 nM in 50% saliva. The sensor has good recovery rate, implying this method has good reliability and repeatability. The detection limit is far below the clinical detection threshold, it would be hopefully used for preliminary screening of drugged driving in real world.

Exploring the Positive User Experience Possibilities Based on Product Emotion Theory: A Beverage Unmanned Retail Terminal Case.

Since the last century, user experience has been regarded as a key concept in the process of product and service design. With the development of positive psychology, the transformation from negative to positive user experience has also taken place in the field of user experience; it emphasizes exploring the future possibility of positive user experience rather than just solving existing problems. Based on the research and analysis of existing literature, this study makes it clear that positive user experience research should be based on the "positive experience," and arousing a positive emotion is conducive to improving positive user experience. On this basis, the product emotion theory is applied to the analysis process of "positive experience." Through word frequency screening, thematic analysis, and correlation calculation, the relationship between product stimulus (object, activity, and identity) and user concern (goal, attitude, and standard) based on positive "user comments" is constructed, and positive user experience is understood from multiple levels. Based on the comment score, the positive user experience interval is divided in order to clarify the improvement direction. Finally, taking the "Angel Orange" unmanned retail terminal as an example, this study carried out an empirical analysis. As an exploratory study, this study can provide some insights into the quantitative research process of positive user experience design that evokes positive emotions from a user's "positive experience" story.

A Data-Driven Expectation Prediction Framework Based on Social Exchange Theory.

Along with the rapid application of new information technologies, the data-driven era is coming, and online consumption platforms are booming. However, massive user data have not been fully developed for design value, and the application of data-driven methods of requirement engineering needs to be further expanded. This study proposes a data-driven expectation prediction framework based on social exchange theory, which analyzes user expectations in the consumption process, and predicts improvement plans to assist designers make better design improvement. According to the classification and concept definition of social exchange resources, consumption exchange elements were divided into seven categories: money, commodity, services, information, value, emotion, and status, and based on these categories, two data-driven methods, namely, word frequency statistics and scale surveys, were combined to analyze user-generated data. Then, a mathematical expectation formula was used to expand user expectation prediction. Moreover, by calculating mathematical expectation, explicit and implicit expectations are distinguished to derive a reliable design improvement plan. To validate its feasibility and advantages, an illustrative example of CoCo Fresh Tea & Juice service system improvement design is further adopted. As an exploratory study, it is hoped that this study provides useful insights into the data mining process of consumption comment.

[Notch1 signaling participates in the release of inflammatory mediators in mouse RAW264.7 cells via activating NF-κB pathway].

Objective To study the effect of Notch1 signaling on the release of inflammatory mediators in lipopolysaccharide (LPS)-induced macrophages and the related mechanism. Methods The expressions of Notch1 and hairy and enhancer of split 1 (Hes1) mRNAs were investigated by reverse transcription PCR (RT-PCR) in mouse RAW264.7 cells after stimulated with 100 ng/mL LPS for 8 hours. Prior to stimulation with LPS, mouse RAW264.7 cells were treated with DAPT (10 µmol/L), an inhibitor of Notch1 signaling, for 1 hour. The concentrations of tumor necrosis factor (TNF-α), interleukin 1ß (IL-1ß), IL-6, nitric oxide (NO) and prostaglandin E2 (PGE2) in cell culture media were measured by ELISA. The mRNA levels of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were examined by RT-PCR. The protein levels of iNOS, COX-2, nuclear factor kappa Bp65 (NF-κBp65) and phosphorylated nuclear factor κB inhibitor α (p-IκBα) were detected by Western blotting. Results The expressions of Notch1 and Hes1 mRNAs significantly increased in mouse RAW264.7 cells after stimulated with LPS. The levels of TNF-α, IL-1ß, IL-6, NO and PGE2 were significantly up-regulated in cell culture media after stimulated with LPS, but the levels of those inflammatory mediators were reduced by DAPT. The mRNA and protein levels of iNOS and COX-2 were significant raised in mouse RAW264.7 cells after stimulated with LPS, while they were inhibited by DAPT. Both IκBα-phosphorylation and NF-κBp65 translocation into nuclear in LPS-induced RAW264.7 cells were also inhibited by DAPT. Conclusion Notch1 signaling activates NF-κB to participate in LPS-induced inflammatory mediator release in macrophages.

RGD mimetics γ-AApeptides and methods of use (US 20,140,004,039 A1): a patent evaluation.

The patent (US 20140004039 A1) claims Arg-Gly-Asp (RGD) mimetics based on a new type of peptidomimetics - γ-AApeptides - which display high binding affinity and specificity to integrin αvß3. Integrin αvß3 is one of the most important proteins involved in tumor angiogenesis and metastasis of solid tumors. It binds tightly to the tripeptide RGD, a prominent recognition motif found in extracellular matrix proteins. As αvß3 is frequently upregulated during tumor angiogenesis, molecules mimicking the RGD recognition motif may target αvß3 specifically and therefore can be used for cancer prevention or targeted diagnosis. Indeed, several positron emission tomography tracers targeting αvß3 are currently under clinical investigation. γ-AApeptides as a new class of peptidomimetics show enhanced stability against proteolytic degradation and are amendable for derivatization due to their enormous chemodiversity. γ-AApeptide-based RGD mimetics, including linear, cyclic and multimeric γ-AApeptides, display comparable binding affinity and specificity to integrin αvß3. These RGD mimetics can be synthesized easily on the solid phase and have been shown to be excellent positron emission tomography tracers by targeting glioblastoma tumor on the mouse model. As γ-AApeptide-based peptidomimetics are more stable than RGD peptides, they could be novel agents for the diagnostics and treatment of various cancers.

Mussel-inspired polydopamine coated mesoporous silica nanoparticles as pH-sensitive nanocarriers for controlled release.

A novel pH-sensitive controlled release system is proposed by using mussel-inspired polydopamine (PDA) coated mesoporous silica nanoparticles (MSNs) as nanocarriers. MSNs with a large pore diameter are synthesized by using 1,3,5-trimethylbenzene as a pore-expanding agent and are modified with a PDA coating by virtue of oxidative self-polymerization of dopamine in neutral pH. PDA coated MSNs are characterized by FTIR, TEM, N2 adsorption and XPS techniques. The PDA coating can work as pH-sensitive gatekeepers to control the release of drug molecules from MSNs in response to the pH-stimulus. Doxorubicin (DOX, an anticancer drug) can be released in the acid media and blocked in the neutral media.

A pH-responsive controlled release system using layered double hydroxide (LDH)-capped mesoporous silica nanoparticles.

A pH-responsive controlled release system is proposed using acid-decomposable layered double hydroxides (LDHs) as inorganic nanovalves by virtue of the electrostatic adsorption of LDH nanosheets on the surface of mesoporous silica nanoparticles (MSNs). Guest molecules (Ru(bpy)3Cl2 in this case) are loaded and encapsulated in a neutral environment. The dissolution of the LDH coatings in an acidic environment triggers the release of the guest molecules from the MSNs.