STUDY ON THE SENSITIVITY OF FUNCTIONALIZEDNANOWIRES USING VARIED CHEMICALS

Silicon nanowire-based metal-oxide-semiconductor field-effect transistors (SiNW MOSFETs) havebeen demonstrated excellent sensitivity and stability after surface modification and functionalization ofnanowires. Chemical molecules have been applied to functionalize the surface of silicon surface. Silanecoupling agents are good candidates for forming self-assembled monolayers (SAMs) by chemicallyinteracting with silicon oxide. Those chemically modified SAMs can provide a functional surface tofurther conjugate biomolecules on SiNW MOSFETs. After functionalization, SiNW MOSFETs withtunably biocompatible surface can sustain a functional biointerface for biological tests. In this work,SiNW MOSFETs were fabricated using the standard I-line stepper of MOS semiconducting process andthen visualized by scanning electron microscopy (SEM). The n-type SiNW MOSFETs devices werefabricated after the process of trimming, the scale of nanowire was down to a level of approximate 165 nm.3-aminopropyl trimethoxysilane (APTMS) and 3-mercaptopropyl trimethoxysilane (MPTMS) SAMs wereindependently used to modify the surface of SiNW MOSFETs for pH sensing in biological buffer solution.Atomic force microscopy (AFM) and electron spectroscopy for chemical analysis (ESCA) were appliedto characterize before and after surface modification. AFM found APTMS and MPTMS were successfullymodified on silicon substrates. The average vertical length of APTMS and MPTMS SAMs from our AFMobservation was around 2.628 nm and 2.698 nm, respectively. ESCA showed the specifically functionalamino (-NH2) groups and mercapto (-SH) groups on each APTMS and MPTMS modified silicon substrates.The specific amine functional group at 399.4 eV occurred after the modification of APTMS on siliconsubstrate in N1s spectra. S2p spectra showed the specific binding at 163.6 eV (C-SH) and 165.8 eV (-C-SS-C-) after the modification of MPTMS on silicon substrate. Those disulfide bonds further influenced theorganization of MPTMS-SAM on the surface; therefore, the APTMS had better SAM performance on oursilicon substrate. On the other hand, electrical measuring system was used for elucidating that the suitablesurface modification would have great impact on the sensing response and sensitivity. Varied biologicalPBS solutions at different pH values showed that unmodified SiNW MOSFETs were sensitive to theH+ ion change. When the pH level of the solution increased, the drain current of the unmodified SiNWMOSFETs decreased accordingly. In comparison with unmodified nanowires in current measurement,the changes of current of APTMS or MPTMS modified nanowires were enhanced in sensing of differentpH solutions. Our results also showed that amino and mercapto groups of APTMS and MPTMS canimprove the protonation and deprotonation reactions in different pH solutions. Both APTMS and MPTMSmodified SiNW MOSFETs in pH sensings possessed good electrical sensing response and sensitivity incontrast with unmodified one. Moreover, in consequence of lower mercaptal groups of MPTMS on NWs,the relatively minor signal responses to varied pH solutions in MPTMS modified SiNW MOSFETs. Theelectrical measurement showed that the amino groups of APTMS significantly improve the sensitivity ofSiNW MOSFET in different pH sensings. Our results showed that adequate modification could provide afunctionable surface for SiNW MOSFETs. We inferred the APTMS modified SiNW MOSFETs could be areal-time sensor for different pH levels detection and further applied in monitoring biological environmentin the future

Paving the Way for Digital Transformation: Investigate Customer Experiences of Using Mobile Apps

Background: Mobile apps have become a critical channel for retailers to interact with their customers and digitalize shopping behaviors in the customer journeys. In the transition of digital transformation, convenience stores have launched mobile apps to interact with and particularly collecting data from their customers. It is critical to investigate customer experiences in using mobile apps because it paves the way for successful digital transformation. This paper aims to investigate the customer experiences of convenience stores’ mobile apps from the online reviews. Method: This study proposed a mobile apps quality model as the theoretical framework to empirically test the online reviews of mobile apps. Large volumes of online reviews generated by customers provide important strategic values for business and service design for mobile apps. This paper collected 40,521 online reviews of two leading convenience stores in Taiwan and analyzed with text analysis and qualitative analysis. Results: Applying text analysis and qualitative analysis, this paper identified the critical quality attributes of mobile apps in the convenience stores that need to be improved. In addition, software quality is the major concern that 7-11 Open Point needs to improve, followed by service quality and information quality respectively. Software quality is also the major concern that FamilyMart app needs to improve the customer experiences, followed by service quality and information quality. Moreover, customer dissatisfaction primarily resulted from problems in software quality and information quality. Instead, convenience, ease of use, and practicability of mobile apps lead to customer satisfaction. Conclusion: The results demonstrate that software quality, information quality, and service quality are critical dimensions in affecting customer experiences in using mobile apps. Although different mobile apps may have different priorities of quality attributes that are needed to be improved, these improvements of mobile apps help to enhance customer experiences and accelerate digital transformation of the convenience stores

Individuation and connection in mother-daughter relationships

The purpose of this study is to explore the processes of individuation and connection in mother-daughter relationships, and describe how these relationships may or may not be facilitated by the intervention of reflections and joint narratives. This study used social constructionism as the epistemological framework and involved in-depth interviews with three mother-daughter pairs. Hermeneutics was used to analyse the data. The participants' experiences were recounted through the researcher's lens in the form of themes that characterised their relationships as well as interactional patterns. Participant's experiences of the research process, and what the researcher believed were helpful and unhelpful behaviours in her interaction with each mother-daughter pair, were discussed. A comparative analysis was also undertaken between the common themes identified in the stories of the mother-daughter pairs and the literature. The information gained could assist women as well as professionals in understanding and respecting mother-daughter relationships in their specific contexts.PsychologyM. A. (Psychology

Novel Quinolone CHM-1 Induces Apoptosis and Inhibits Metastasis in a Human Osterogenic Sarcoma Cell Line

[[abstract]]Novel 2-phenyl-4-quinolone compounds have potent cytotoxic effects on different human cancer cell lines. In this study, we examined anticancer activity and mechanisms of 20-fluoro-6,7-methylenedioxy-2-phenyl-4-quinol one (CHM-1) in human osterogenic sarcoma U-2 OS cells. CHM-1-induced apoptosis was determined by flow cytometric analysis, DAPI staining, Comet assay, and caspase inhibitors. CHM-1-inhibited cell migration and invasion was assessed by a wound healing assay, gelatin zymography, and a Transwell assay. The mechanisms of CHM-1 effects on apoptosis and metastasis signaling pathways were studied using Western blotting and gene expression. CHM-1 induced G2/M arrest and apoptosis at an IC50 (3 mu M) in U-2 OS cells and caspase-3, -8, and -9 were activated. Caspase inhibitors increased cell viability after exposure to CHM-1. CHM-1-induced apoptosis was associated with enhanced ROS generation, DNA damage, decreased Delta Psi(m), levels, and promotion of mitochondrial cytochrome c release. CHM-1 stimulated mRNA expression of caspase-3, -8, and -9, AIF, and Endo G. In addition, CHM-1 inhibited cell metastasis at a low concentration (<3 mu M). CHM-1. inhibited the cell metastasis through the inhibition of MMP-2, -7, and -9. CHM-1 also decreased the levels of MAPK signaling pathways before leading to the inhibition of MMPs. In summary, CHM-1 is a potent inducer of apoptosis, which plays a role in the anticancer activity of CHM-1. (C) 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1.637-1644, 200

Oxygen Vacancy Induced Ferromagnetism in V2_2O5−x_{5-x}

{\it Ab initio} calculations within density functional theory with generalized gradient approximation have been performed to study the effects of oxygen vacancies on the electronic structure and magnetism in undoped V$_2$O$_{5-x}$ ($0 < x < 0.5$). It is found that the introduction of oxygen vacancies would induce ferromagnetism in V$_2$O$_{5-x}$ with the magnetization being proportional to the O vacancy concentration $x$. The calculated electronic structure reveals that the valence electrons released by the introduction of oxygen vacancies would occupy mainly the neighboring V $d_{xy}$-dominant band which then becomes spin-polarized due to intra-atomic exchange interaction, thereby giving rise to the half-metallic ferromagnetism.Comment: To be published as a Letter in J. Phys. Soc. Japa

Site-directed in vitro immunization leads to a complete human monoclonal IgG4λ that binds specifically to the CDR2 region of CTLA-4 (CD152) without interfering the engagement of natural ligands

<p>Abstract</p> <p>Background</p> <p>The ability to acquire fully human monoclonal antibodies (mAbs) with pre-defined specificities is critical to the development of molecular tags for the analysis of receptor function in addition to promising immunotherapeutics. Yet most of the arriving affinity maturated and complete human immunoglobulin G (IgG) molecules, which are actually derived from single human B cells, have not widely been used to study the conserved self antigens (Ags) such as CD152 (cytotoxic T lymphocyte antigen-4, CTLA-4) because proper hosts are lacking.</p> <p>Results</p> <p>Here we developed an optimized protocol for site-directed <it>in vitro </it>immunizing peripheral blood mononuclear cells (PBMC) by using a selected epitope of human CD152, an essential receptor involved in down-regulation of T cell activation. The resultant stable trioma cell lines constantly produce anti-CD152 mAb (γ4λhuCD152), which contains variable (V) regions of the heavy chain and the light chain derived from the VH3 and Vλ human germline genes, respectively, and yet displays an unusual IgG4 isotype. Interestingly, γ4λhuCD152 has a basic pI not commonly found in myeloid monoclonal IgG4λs as revealed by the isoelectric focusing (IEF) analysis. Furthermore, γ4λhuCD152 binds specifically, with nanomolar affinity, to an extracellular constituency encompassing the putative second complementarity determining region (CDR2) of CD152, whereby it can react to activated CD3⁺cells.</p> <p>Conclusion</p> <p>In a context of specific cell depletion and conditioned medium,<it>in vitro </it>induction of human Abs against a conserved self Ag was successfully acquired and a relatively basic mAb, γ4λhuCD152, with high affinity to CDR2 of CD152 was thus obtained. Application of such a human IgG4λ mAb with designated CDR2 specificity may impact upon and prefer for CD152 labeling both <it>in situ </it>and <it>ex situ</it>, as it does not affect the binding of endogenous B7 ligands and can localize into the confined immunological synapse which may otherwise prevent the access of whole IgG1 molecules.</p