Reliability and validity study of the Indonesian Smartphone Application-Based Addiction Scale (SABAS) among college students.

Background/objective: Smartphone addiction, smartphone dependence, and compulsive smartphone use all describe similar phenomena that can cause problems in everyday daily life in many countries worldwide. Most scholars agree that it is the applications on smartphones that individuals have problems with rather than the smartphone itself. For this reason, smartphone application-based addiction is an issue of concern and one instrument has been specifically developed to assess this risk, namely, the Smartphone Application-Based Addiction Scale (SABAS).

Scattering of spoof surface plasmon polaritons in defect-rich THz waveguides.

We report on the first observation of 'Spoof' Surface Plasmon Polariton (SPP) scattering from surface defects on metal-coated 3D printed, corrugated THz waveguiding surfaces. Surface defects, a result of the printing process, are shown to assist the direct coupling of the incident free-space radiation into a spoof SPP wave; removing the need to bridge the photon momentum gap using knife-edge or prism coupling. The free space characteristics, propagation losses and confinement of the spoof SPPs to the surface are measured, and the results are compared to finite-difference time domain simulations.

A functional connectome: regulation of Wnt/TCF-dependent transcription by pairs of pathway activators.

Background: Wnt/β-catenin signaling is often portrayed as a simple pathway that is initiated by Wnt ligand at the cell surface leading, via linear series of interactions between 'core pathway' members, to the induction of nuclear transcription from genes flanked by β-catenin/TCF transcription factor binding sites. Wnt/β-catenin signaling is also regulated by a much larger set of 'non-core regulators'. However the relationship between 'non-core regulators' is currently not well understood.

Lighting up insulin action.

Understanding the mechanism of insulin action remains one of the most important challenges in modern medical biology. Recent advances in cell imaging techniques, increased processing power of computers and the internet, and the introduction of novel fluorescent reagents such as green fluorescent proteins (GFPs) have revolutionized our ability to scrutinize insulin action by time-lapse microscopy at the single-cell level. This article outlines some of the advances made in the authors' laboratory, with particular reference to imaging the movements of the insulin-sensitive glucose transporter, GLUT4, and the generation of phosphoinositide lipids.

Rapid caspase-3 activation during apoptosis revealed using fluorescence-resonance energy transfer.

Caspase-3 is a crucial component of the apoptotic machinery in many cell types. Here, we report the timescale of caspase-3 activation in single living cells undergoing apoptosis. This was achieved by measuring the extent of fluorescence resonance energy transfer within a recombinant substrate containing cyan fluorescent protein (CFP) linked by a short peptide possessing the caspase-3 cleavage sequence, DEVD, to yellow fluorescent protein (YFP; i.

Naturally-occurring and recombinant forms of the aspartic proteinases plasmepsins I and II from the human malaria parasite Plasmodium falciparum.

Comparable kinetic parameters were derived for the hydrolysis of peptide substrates and the interaction of synthetic inhibitors with recombinant and naturally-occurring forms of plasmepsin II. In contrast, recombinant plasmepsin I was extended by 12 residues at its N-terminus relative to its naturally-occurring counterpart and a 3-10-fold diminution in the k(cat) values was measured for substrate hydrolysis by the recombinant protein. However, comparable Ki values were derived for the interaction of two distinct inhibitors with both forms of plasmepsin I, thereby validating the use of recombinant material for drug screening.

Expression and characterisation of plasmepsin I from Plasmodium falciparum.

Two aspartic proteinases, plasmepsins I and II, are present in the digestive vacuole of the human malarial parasite Plasmodium falciparum and are believed to be essential for parasite degradation of haemoglobin. Here we report the expression and kinetic characterisation of functional recombinant plasmepsin I. In order to generate active plasmepsin I from its precursor, an autocatalytic cleavage site was introduced into the propart of the zymogen by mutation of Lys110P to Val (P indicates a propart residue).

High level expression and characterisation of Plasmepsin II, an aspartic proteinase from Plasmodium falciparum.

DNA encoding the last 48 residues of the propart and the whole mature sequence of Plasmepsin II was inserted into the T7 dependent vector pET 3a for expression in E. coli. The resultant product was insoluble but accumulated at approximately 20 mg/l of cell culture.