Nanotechnology

Droplet microfluidics are a powerful approach for hydrogel cell encapsulations. Much of the field has focused on single-cell encapsulations with pico-nanoliter droplet volumes necessary for single-cell sequencing or high-throughput screening. These small volumes, however, limit the use of hydrogel droplets for tissue engineering or cell therapies. We describe simple droplet microfluidics to generate millimeter-sized alginate droplets and demonstrate their use for cell encapsulations. This effort builds on our recent efforts [1], specifically by replacing the glass slide forming the bottom layer of the chamber with a more hydrophobic acrylic (PMMA) layer to improve the alginate-in-oil droplet formation. Using glass layer and PMMA layer devices, we characterized the tunable production of water-in-oil droplets (average droplet lengths ranged from 0.8 to 3.7 mm). Next, PMMA layer devices were used to demonstrate the tunable generation of alginate-in-oil droplets (average droplet lengths ranged from 3-6 mm). Increasing the flow ratio (Q.ratio = Q.oil/Q.alginate) led to more uniform droplets as measured by the coefficient of variance (COV%), which was approximately 5%. Finally, a proof-of-use experiment used HUVEC-encapsulated alginate droplets as part of a scratch-healing assay. Specifically, HUVEC-encapsulated droplets (AH droplets) led to recovery of 3T3 fibroblast monolayers compared to no droplets or cell-free droplets (A droplets). Our results extended the use of simple microfluidics to generate and retrieve millimeter-sized alginate droplets for effective cell encapsulations.

Brownian ratchet based particle separation systems for application in lab on chip devices have drawn interest and are subject to ongoing theoretical and experimental investigations. We demonstrate a compact microfluidic particle separation chip, which implements an extended on-off Brownian ratchet scheme that actively separates and sorts particles using periodically switching magnetic fields, asymmetric sawtooth channel sidewalls, and Brownian motion. The microfluidic chip was made with Polydimethylsiloxane (PDMS) soft lithography of SU-8 molds, which in turn was fabricated using Proton Beam Writing. After bonding of the PDMS chip to a glass substrate through surface activation by oxygen plasma treatment, embedded electromagnets were cofabricated by the injection of InSn metal into electrode channels. This fabrication process enables rapid production of high resolution and high aspect ratio features, which results in parallel electrodes accurately aligned with respect to the separat...

Introduction: This study presents a microfluidic tumor microenvironment (TME) model for evaluating the anti-metastatic efficacy of a novel thienopyrimidines analog with anti-cancer properties utilizing an existing commercial platform. The microfluidic device consists of a tissue compartment flanked by vascular channels, allowing for the co-culture of multiple cell types and providing a wide range of culturing conditions in one device.Methods: Human metastatic, drug-resistant triple-negative breast cancer (TNBC) cells (SUM159PTX) and primary human umbilical vein endothelial cells (HUVEC) were used to model the TME. A dynamic perfusion scheme was employed to facilitate EC physiological function and lumen formation.Results: The measured permeability of the EC barrier was comparable to observed microvessels permeability in vivo. The TNBC cells formed a 3D tumor, and co-culture with HUVEC negatively impacted EC barrier integrity. The microfluidic TME was then used to model the intravenou...

An easy shortcut synthesis of thermally stable, near-monodisperse Bi nanoparticles from BiCl 3 and Na[N(SiMe 3 ) 2 ] is described. The diameters of the Bi nanoparticles are controlled in the range of 4-29 nm by varying the amounts of BiCl 3 and Na[N(SiMe 3 ) 2 ] employed. Standard deviations in their diameter distributions are 5-15% of the mean diameters, consistent with near monodispersity. These Bi nanoparticles are shown to be the best currently available catalysts for the solution-liquid-solid (SLS) growth of high-quality CdSe quantum wires.

Herein, we report the detailed pathway for the formation of CdSe quantum belts (QBs). We show that CdX 2 (X = OAc, I) compounds in long-chain primary-amine solvents form lamellar structures that serve as templates for the formation of (CdSe) 13 nanoclusters. The resulting amine-template nanocluster composites spontaneously organize into double-lamellar assemblies. Recrystallization of the nanoclusters within the templates affords CdSe quantum belts (QBs) having widths and thicknesses determined by the periodicities of the double-lamellar nanostructures. This template synthesis affords excellent control over QB thickness and accounts for the excellent optical properties of the QBs. The preparation of CdSe nanoribbons, nanoplatelets, and nanosheets was reported independently by Hyeon and coworkers 1,2 and by Ithurria and Dubertret 3,4 under synthetic conditions similar to those employed here. We subsequently demonstrated that CdSe quantum belts, which were morphologically comparable to the nanoribbons of Hyeon and co-workers, 1 exhibit photoluminescence quantum yields of 30 ( 10%. 5 Such high photoluminescence efficiencies are unprecedented for pseudo-one-dimensional colloidal semiconductor nanostructures and indicate that excitons are effectively transported over micrometerscale diffusion distances parallel to the QB long axes. A remarkable aspect of the nanoribbon, nanoplatelet, nanosheet, and QB syntheses is the flat, layer-like, morphologies of the nanocrystals. Normally, nanocrystals grown in solution have dot 6 or rod-like morphologies, 7À10 or wire morphologies if appropriate catalyst nanoparticles are present, 11À13 or a selfassembly mechanism is active. 14À17 Additionally, the reaction temperatures employed (∼70À120 °C) are quite low for nanocrystal syntheses. Consequently, the mechanisms or pathway by which these nanostructures form must be unusual. Hyeon and co-workers, who demonstrated that dissolution of CdCl 2 in primary-amine solvents resulted in the formation of lamellar CdCl 2 (amine) 2 complexes. 2 They showed that such lamellar precursors served as templates for the formation of planar CdSe nanosheets. In a subsequent paper, Hyeon and coworkers determined that (CdSe) 33,34 and (CdSe) 13 nanoclusters were intermediates in the process. Here, we elucidate a similar pathway for the formation of CdSe QBs with experimental detail that accounts for the morphology produced. We demonstrate that the templates adopt doublelamellar structures that are responsible for the QB morphologies. We confirm that the intermediate nanoclusters are indeed entrained within the template structures. We show that the conversion of (CdSe) 13 nanoclusters to CdSe QBs is reversible. We also show that the double-lamellar assemblies of (CdSe) 13 nanoclusters and CdSe QBs dissociate or unbundle in different dimensions, the (CdSe) 13 nanoclusters into lateral sheets and the QBs into vertical stacks. Finally, we report the synthesis of QBs of two specific thicknesses and demonstrate that the thinner QBs are intermediates in the formation of the thicker QBs. ' EXPERIMENTAL SECTION Materials. n-Octylamine (n-OA) from Aldrich (+99%) and Alfa Aesar (99%), selenourea (99.9%, metal basis) from Alpha Aesar, Cd(OAc) 2 3 2H 2 O (Aldrich), trioctylphosphine (TOP) from Sigma-Aldrich (97%), and oleylamine (or cis-9-octadecenylamine) from TCI (>40.0% by GC) and Sigma-Aldrich (technical grade, 70%) were used as received and stored under N 2 . Toluene from Sigma-Aldrich

A simple and potentially general means of eliminating the planar defects and phase alternations that typically accompany the growth of semiconductor nanowires by catalyzed methods is reported. Nearly phase-pure, defectfree wurtzite II-VI semiconductor quantum wires are grown from solid rather than liquid catalyst nanoparticles. The solidcatalyst nanoparticles are morphologically stable during growth, which minimizes the spontaneous fluctuations in nucleation barriers between zinc blende and wurtzite phases that are responsible for the defect formation and phase alternations. Growth of single-phase (in our cases the wurtzite phase) nanowires is thus favored.

Defect engineering is a strategy that has been widely used to design active semiconductor photocatalysts. However, understanding the role of defects, such as oxygen vacancies, in controlling photocatalytic activity remains a challenge. Here we report the use of chemically-triggered fluorogenic probes to study the spatial distribution of active regions in individual tungsten oxide nanowires using super-resolution fluorescence microscopy. The nanowires show significant heterogeneity along their lengths for the photocatalytic generation of hydroxyl radicals. Through quantitative, coordinate-based colocalization of multiple probe molecules activated by the same nanowires, we demonstrate that the nanoscale regions most active fo the photocatalytic generation of hydroxyl radicals also possess a greater concentration of oxygen vacancies. Chemical modifications to remove or block access to surface oxygen vacancies, supported by calculations of binding energies of adsorbates to different surface sites on tungsten oxide, show how these defects control catalytic activity at both the ensemble and single-particle level. These findings reveal that clusters of oxygen vacancies activate surface-adsorbed water molecules towards photooxidation to produce hydroxyl radicals, a critical intermediate in several photocatalytic reactions.

A simple and potentially general means of eliminating the planar defects and phase alternations that typically accompany the growth of semiconductor nanowires by catalyzed methods is reported. Nearly phase-pure, defectfree wurtzite II-VI semiconductor quantum wires are grown from solid rather than liquid catalyst nanoparticles. The solidcatalyst nanoparticles are morphologically stable during growth, which minimizes the spontaneous fluctuations in nucleation barriers between zinc blende and wurtzite phases that are responsible for the defect formation and phase alternations. Growth of single-phase (in our cases the wurtzite phase) nanowires is thus favored.

Heterostructured ZnSe-ZnTe quantum wires are grown by the solution-liquid-solid (SLS) mechanism. The nature of the axial or radial heterostructure obtained is strongly influenced by the growth sequence and related synthetic conditions. Compositionally graded ZnSe x Te 1-x wires, ZnSe-ZnTe axial heterostructures containing a ZnSe x Te 1-x transitional segment, ZnSe-ZnTe wires with sharp axial heterojunctions, and radial core-shell ZnSe-ZnTe quantum wires have been selectively prepared. The axial and radial quantum-wire heterostructures are characterized microscopically and spectroscopically.

Biosynthesis of nanoparticles is the preferred route for the fabrication of biocompatible and cheaper drugs. In this study, the extract and major secondary metabolite from Helichrysum aureonitens, 3,5-dihydroxy-6,7,8-trimethoxyflavone, were used to synthesize silver and zinc oxide nanoparticles. Spectroscopic and microscopic techniques confirmed the formation of the nanoparticles. The flavone alone showed higher DPPH radical scavenging ability (IC50 = 487.1 μg mL−1) relative to the control, butylated hydroxytoluene. In addition, silver nanoparticles synthesized using the flavone had higher ferric reducing potential (Fe3+ to Fe2+) compared to the other test samples. The cytotoxic activity of the plant extract, the flavone, and their biosynthesized nanoparticles was also investigated using the MTT assay against the cancerous MCF-7 (breast adenocarcinoma) and A549 (human lung adenocarcinoma)), and non-cancerous HEK293 (human embryonic kidney) cell lines. The plant extract decreased the...

Single walled carbon nanotubes (SWNTs), with high carboxylic acid content, were chemically modified in order to develop hydrophilic and organophilic analogues. The hydrophilic SWNTs were prepared by wrapping a water-soluble polymer, namely poly (sodium 4-styrene sulfonate) (PSSNa) around the pristine SWNTs, while the organophilic SWNTs were developed by forming amide bonds with oleylamine (C 18 H 37 N). The modification of carbon nanotubes was studied through IR spectroscopy. Moreover, the sorption properties of pristine and modified carbon nanotubes were studied by using adsorbates, which differ in polarity (i.e. water, ethanol and n-hexane). Based on these measurements it is concluded that the sorption behaviour of the SWNTs has been completely modified after the treatment, since the hydrophilic and organophilic carbon nanotubes reveal enhanced selectivity of water and n-hexane respectively.

Magnetic graphite films have been realized through encapsulation of magnetic nanoparticles within graphitic layers. In addition to their unique magnetic characteristics, these core-shell structures exhibit remarkable stability owing to the resistant carbon shell around the functional particles that protects them against degradation and reduces interparticle magnetic coupling. Inspired by these advancements, we have induced magnetism into parallel-oriented carbon nanotubes (CNTs) by in situ inclusion of magnetic iron carbide nanocrystals inside the tube walls. The resulting ferromagnetic composite consisting of monodisperse, perfectly aligned, and inherently open-ended CNTs can open up new prospects in high-flux magnetic separations and microfluidics, bio-capturing, and controlled drug delivery and release, while the stability of the wall-encapsulated magnetic particles prolongs material durability and extends the limits of application conditions without compromising functionality. Doping of CNTs with magnetic particles proceeds through loading of the tube core, e.g., by capillary wettability, or by attachment onto the tube external surface after appropriate modification. Yet, although functionality has been demonstrated, the integrity of the resulting composites is often compromised by oxidation of the environmentexposed particles, agglomeration and detachment upon processing under a magnetic field, and non-uniform particle distribution caused by inefficient surface treatment and/or incomplete opening of the nanotube ends. In addition, the presence of particles blocks the tubes rendering the material inappropriate for applications where fast and uninterrupted flow of substances is desired. Biological separations, in particular, require high sample throughput and simultaneous processing of multiple samples in a fraction of the usual separation time. Most magnetic separation methods, however, while effective, operate in a batch rather than in a flow mode, making them too slow and inefficient for optimal use in a high-throughput setting. The use of magnetic CNTs can overcome this challenge as CNTs, when appropriately engineered, can exhibit extremely high permeability, owing to the inherent smoothness of the nanotube inner surfaces that provides nearly frictionless molecular transport. The morphological characteristics of the synthesized nanotubes are extracted from microscopy data shown in Figure . Figure 1a reveals that one CNT extends out of almost every COMMUNICATION www.MaterialsViews.com

Although hollow nanostructures, such as nanotubes, represent a major portion of nanoscaled materials with a tremendously large application range, a detailed evaluation of their internal characteristics still remains elusive. Transmission electron microscopy is the most common analytical technique to examine the internal configuration of these structures, yet it can only provide evidence of a minimal portion of the overall material, thus, it cannot be accurately generalized. In the present paper, in addition to electron microscopy and other spot‐size analysis methods (X‐ray diffraction, Raman spectroscopy, etc.), a combination of techniques including adsorption, permeability, and relative permeability are employed in order to provide important insights into various crucial details of the overall internal surface and hollow‐space characteristics of carbon nanotube (CNT) arrays and membranes. The CNT arrays are fabricated using anodized alumina as a template in a flow‐through chemical ...

Magnetic cellulose (MC) is prepared by hydrolysis of iron precursors in an aqueous dispersion of cellulose nanofibres. A thin, flexible film was then prepared by removing the water and drying the sample in a hot press at 110°C followed by the removal of the water. Structural analysis of MC was performed and correlated with the measurement of electromagnetic properties. The magnetic cellulose showed high magnetic saturation of 68 emu/g with characteristic superparamagnetic behaviour, and conductivity in a range of semiconductors, with an increase of DC conductivity with increasing temperature. Modification of cellulose with Fe3O4 has a positive effect on the DC conductivity and lower limit that needs to be exceeded to achieve a stable and sustainable conductivity in the range of ~5-20 ×10-9 (Ω cm)-1 @30 °C is 65 wt% of the Fe3O4 for studied MC composites. The surface roughness of the magnetic cellulose shows a dynamic change with increasing temperature, which is closely related to th...

Here, we present a systematic study about the effect of the pore length and its diameter on the specular reflection in nanoporous anodic alumina. As we demonstrate, the specular reflection can be controlled at will by structural tuning (i.e., by designing the pore geometry). This makes it possible to produce a wide range of Fabry-Pérot interferometers based on nanoporous anodic alumina, which are envisaged for developing smart and accurate optical sensors in such research fields as biotechnology and medicine. Additionally, to systematize the responsiveness to external changes in optical sensors based on nanoporous anodic alumina, we put forward a barcode system based on the oscillations in the specular reflection.

This study aimed to analyze the influence of salesmanship, relationship quality, and consumer value on consumer loyalty and also to determine which variables are the dominant influence among three variables salesmanship, relationship quality, and consumer value on consumer loyalty. The population used in this research is the consumer who has ever bought furniture at PT.MUSTIKA JATI JEPARA, Jl. KH. Wahid Hasyim KM 2, Jepara. The samples are obtained by using purposive sampling method, that the sampling technique is based on certain characteristics, which is considered to have links with the characteristics of the population that has been determination before. Methods of data analysis using multiple linear regression analysis. The results showed that the variables of salesmanship, relationship quality and consumer value simultaneously significant effect on consumer loyalty. Then partially variable relationship quality has the highest significant effect on consumer loyalty, while the c...

Tin oxide (SnO2), a versatile metal oxide due to its wide range of applications and its nature as an amphoteric oxide, has attracted researchers globally for many decades. Hydrothermal synthesis of wide band gap oxides with controllable nano shape and size is of primary attraction leading to myriad areas of applications such as electrodes in Lithium-ion batteries, gas sensing, photo-catalyst etc. to name a few. In this work, we have synthesized different types of nanostructures of Tin oxide through low temperature(180oC) Hydrothermal process by varying the concentration of its precursor solution (SnCl4.5H2O) from 0.0625M to 0.25M. The characterization of as -Synthesized SnO2 done using UV-Vis spectroscopy, Scanning Electron Microscopy (SEM), Energy Dispersive X ray (EDX) and X-Ray Diffraction (XRD) confirm synthesis of tin oxide and formation of various nanostructures as a function of concentration of the precursor solution. The evolution of various shapes of nanostructures has been...

Silver nanoparticles (AgNPs), are amongst the utmost striking nanosized materials that are extensively applied in a variety of biomedical applications which includes diagnostic use, disease management, medical device coating, drug delivery and for personal health care. With the growing interest and the use of AgNPs in the health care sector, it is becoming essential for a better understanding of AgNPs mechanism of action like biological interaction, their possible toxicity, and safety concern to human exposure. AgNPs have been the subjects of researchers attention and interest due to the unique properties and quality such as shape and size depending optical, electrical, and antimicrobial potentials (antibacterial, antifungal, antiviral etc.). In this review, a short overview of AgNPs synthesis approach is presented (physical, chemical, and biological or green synthesis) and it also delivers a historical outlook of AgNPs application as an antimicrobial agent which includes combined e...

By using isomeric N,N′-di(2-pyridyl)adipoamide (L 1 ), N,N′-di(3-pyridyl)adipoamide (L 2 ) and N,N′-di(4-pyridyl)adipoamide (L 3 ) and isomeric 1,2-benzenedicarboxylic acid (1,2-H 2 BDC), 1,3-benzenedicarboxylic acid (1,3-H 2 BDC) and 1,4-benzenedicarboxylic acid (1,4-H 2 BDC), eight Zn(II) and Cd(II , have been synthesized under hydrothermal conditions. Complexes 1, 4, and 5 form 1D double-looped chain, 1D chain with loops and 2D layer with loops, respectively, and complex 6 exhibits a 1D ladder chain. Complex 2 shows rare 3-fold interpenetrated hcb layers, in which each layer interdigitates with other four parallel layers by directing the 1,3-BDC ligands into the windows of the adjacent nets, whereas complexes 3 and 8 forms planar and undulated hcb layers, respectively. Complex 7 shows a 3D selfpenetrating net of {4 24 .5.6 3 }-ilc topology with a unique arrangement for the L 2 spacer ligands. The L 1 ligands in complexes 3 and 8 adopt the new tetradentate bonding mode involving chelation and bridge through two pyridyl nitrogen atoms and two amide oxygen atoms, whereas the L 2 and L 3 ligands in other complexes show the bidentate bonding mode through the two pyridyl nitrogen atoms. The various bonding modes and the ligand-isomerism of the spacer ligands BDC 2-and L 1 -L 3 as well as the identity of the metal center play important roles in determining the structural diversity.

Screen technology for "smart" devices continues to advance as researches seek to enhance display performance by reducing energy consumption and improving color characteristics. To that end, researchers are turning to organic light-emitting diodes (OLEDs) as the display materials due to higher energy saving and richer color compared to liquid crystal displays (LCDs). However, one major setback of the OLED technology is that the devices are very sensitive to the impurities present in the OLED materials, impacting device lifetime, stability, and overall performance. The isolation of large quantities of the main OLED components from the synthetic impurities is challenging using the traditional purification process (i.e., train sublimation), which has poor reproducibility, and high capital and operating cost. Supercritical fluid chromatography (SFC) could lend itself as an alternative technique for the profiling of impurities and their purification. In this study, we investigated the use of SFC to analyze a mixture of amorphous monomeric molecular glasses with charge-transporting property typical of OLED materials. The separation behavior of four different chromatographic columns containing the stationary phases 1aminoanthracene (1-AA), naphthyl, 2-ethylpyridine, and C-18 were examined to perform the SFC separations. The effect of using three different co-solvents (i.e., isopropyl alcohol, acetonitrile, and tetrahydrofuran) to the CO2 mobile phase on the separation selectivity and resolution was also investigated. For the probe mixture used, the naphthyl column in combination with the addition of acetonitrile as co-solvent provided the best separation in terms of resolution. The SFC method was farther optimized for co-solvent composition, temperature, pressure, and flow rate. The SFC analysis showed high resolution and short analysis time compared to HPLC, and also provided for the separation of small components that have been attributed to impurities in the sample.

The interaction of actin filaments with myosin is crucial to cell motility, muscular contraction, cell division and other processes. The in vitro motility assay involves the motion of actin filaments on a substrate coated with myosin, and is used extensively to investigate the dynamics of the actomyosin system. Following on from previous work, we propose a new mechanical model of actin motility on myosin, wherein a filament is modeled as a chain of beads connected by harmonic springs. This imposes a limitation on the ‘stretching’ of the filament. The rotation of one bead with respect to its neighbors is also constrained in similar way. We implemented this model and used Monte Carlo simulations to determine whether it can predict the directionality of filament motion. The principal advantages of this model are that we have removed the empirically correct but artificial assumption that the filament moves like a ‘worm’ i.e. the head determines the direction of movement and the rest of ...

The actin-myosin system, responsible for muscle contraction, is also the force-generating element in dynamic nanodevices operating with surface-immobilized motor proteins. These devices require materials that are amenable to micro-and nano-fabrication, but also preserve the bioactivity of molecular motors. The complexity of the protein-surface systems is greatly amplified by those of the polymer-fluid interface; and of the structure and function of molecular motors, making the study of these interactions critical to the success of molecular motor-based nanodevices. We measured the density of the adsorbed motor protein (heavy meromyosin, HMM) using quartz crystal microbalance; and motor bioactivity with ATPase assay, on a set of model surfaces, i.e., nitrocellulose, polystyrene, poly(methyl methacrylate), and poly(butyl methacrylate), poly(tert-butyl methacrylate). A higher hydrophobicity of the adsorbing material translates in a higher total number of HMM molecules per unit area, but also in a lower uptake of water, and a lower ratio of active per total HMM molecules per unit area. We also measured the motility characteristics of actin filaments on the model surfaces, i.e., velocity, smoothness and deflection of movement, determined via in vitro motility assays. The filament velocities were found to be controlled by the relative number of active HMM per total motors, rather than their absolute surface density. The study allowed the formulation of the general engineering principles for the selection of polymeric materials for the manufacturing of dynamic nanodevices using protein molecular motors.

Micro-contact printing, μCP, is a well-established soft-lithography technique for printing biomolecules. μCP uses stamps made of Poly(dimethylsiloxane), PDMS, made by replicating a microstructured silicon master fabricated by semiconductor manufacturing processes. One of the problems of the μCP is the difficult control of the printing process, which, because of the high compressibility of PDMS, is very sensitive to minute changes in the applied pressure. This over-sensitive response leads to frequent and/or uncontrollable collapse of the stamps with high aspect ratios, thus decreasing the printing accuracy and reproducibility. Here we present a straightforward methodology of designing and fabricating PDMS structures with an architecture which uses the collapse of the stamp to reduce, rather than enlarge the variability of the printing. The PDMS stamp, organized as an array of pyramidal micro-posts, whose ceiling collapses when pressed on a flat surface, replicates the structure of t...

The fabrication and operation of biodevices require the accurate control of the concentration of the bioactive molecules on the surface, as well as the preservation of their bioactivity, in particular proteins that have a significant propensity for surface-induced denaturation. A method that allows the adsorption of proteins on 'combinatorial' micro/nano-surfaces fabricated via laser ablation of a thin metal layer deposited on a polymer that has been proposed allows for the up to 10-fold amplification of the protein adsorption on micro/nanostructures. This contribution studies the relationship between amplification of adsorption and protein molecular characteristics (total molecular surface; and charge-and hydrophobicity-specific surface).

Many areas of biochemistry and molecular biology, both fundamental and applications-orientated, require an accurate construction, representation and understanding of the protein molecular surface and its interaction with other, usually small, molecules. There are however many situations when the protein molecular surface gets in physical contact with larger objects, either biological, such as membranes, or artificial, such as nanoparticles. The contribution presents a methodology for describing and quantifying the molecular properties of proteins, by geometrical and physico-chemical mapping of the molecular surfaces, with several analytical relationships being proposed for molecular surface properties. The relevance of the molecular surface-derived properties has been demonstrated through the calculation of the statistical strength of the prediction of protein adsorption. It is expected that the extension of this methodology to other phenomena involving proteins near solid surfaces, in particular the protein interaction with nanoparticles, will result in important benefits in the understanding and design of protein-specific solid surfaces.

Tujuan dari penelitian ini adalah untuk mengetahui Kinerja Keuangan Berdasarkan Rasio Rentabilitas Pada PT. PLN (Persero) Area Bulukumba di Kota Bulukumba. Adapun populasi dalam penelitian ini adalah laporan keuangan PT. PLN (Persero) Area Bulukumba di Kota Bulukumba. Sedangkan sampel pada penelitian ini adalah Neraca dan Laporan laba rugi PT. PLN (Persero) Area Bulukumba di Kota Bulukumba dalam lima tahun terakhir (2011-2015). Teknik pengumpulan data dilakukan dengan cara dokumentasi. Teknik analisis data yang digunakan adalah Rasio Rentabilitas yaitu Net Profit Margin,Return On Investment dan Return On Equity . Hasil penelitian yang diperoleh bahwa kemampuan kinerja keuangan PT. PLN (Persero) Area Bulukumba di Kota Bulukumba pada tahun 2011-2015 Net Profit Margin dan Return On Investmentdi katakana baik karena beradi di atas rata-rata industri. Dimana proporsi peningkatan presentase Earning After Interest and Tax, Sales dan Assets sama-sama meningkat, walaupun rata-rata presentase...

This study constitutes a demonstration of the biological route to controlled nano-fabrication via modular multi-functional inorganic-binding peptides. Specifically, we use gold-and silica-binding peptide sequences, fused into a single molecule via a structural peptide spacer, to assemble presynthesized gold nanoparticles on silica surface, as well as to synthesize nanometallic particles in situ on the peptide-patterned regions. The resulting film-like gold nanoparticle arrays with controlled spatial organization are characterized by various microscopy and spectroscopy techniques. The described bio-enabled, single-step synthetic process offers many advantages over conventional approaches for surface modifications, self-assembly and device fabrication due to the peptides' modularity, inherent biocompatibility, material specificity and catalytic activity in aqueous environments. Our results showcase the potential of artificially-derived peptides to play a key role in simplifying the assembly and synthesis of multi-material nano-systems in environmentally benign processes.

By evolution, nature has created an astonishing collection of micro and nano scale structures. In this paper, we discuss the development of a "molecular toolkit" which builds the basis for the biomimetic natural processes. As the first step, we have demonstrated the capability to identify polypeptides that specifically bind to an inorganic (platinum) and differentiate between this metal and other inorganic surfaces such as silicon dioxide and gold. We have achieved the integration of the polypeptides with a microfabricated heterogeneous substrate, by selectively immobilizing them on the specific inorganic materials. In the future, this "toolkit", integrating micro-, nano-and biotechnology, can be used for the development of new generation of biomimetic manufacturing process.

Semiconductor nanocrystal quantum dots are utilized in numerous applications in nano-and biotechnology. In device applications, where several different material components are involved, quantum dots typically need to be assembled at explicit locations for enhanced functionality. Conventional approaches cannot meet these requirements where assembly of nanocrystals is usually material-nonspecific, thereby limiting the control of their spatial distribution. Here we demonstrate directed self-assembly of quantum dot emitters at material-specific locations in a color-conversion LED containing several material components including a metal, a dielectric, and a semiconductor. We achieve a spatially selective immobilization of quantum dot emitters by using the unique material selectivity characteristics provided by the engineered solid-binding peptides as smart linkers. Peptide-decorated quantum dots exhibited several orders of magnitude higher photoluminescence compared to the control groups, thus, potentially opening up novel ways to advance these photonic platforms in applications ranging from chemical to biodetection.

By evolution, nature has created an astonishing collection of micro and nano scale structures. In this paper, we discuss the development of a "molecular toolkit" which builds the basis for the biomimetic natural processes. As the first step, we have demonstrated the capability to identify polypeptides that specifically bind to an inorganic (platinum) and differentiate between this metal and other inorganic surfaces such as silicon dioxide and gold. We have achieved the integration of the polypeptides with a microfabricated heterogeneous substrate, by selectively immobilizing them on the specific inorganic materials. In the future, this "toolkit", integrating micro-, nano-and biotechnology, can be used for the development of new generation of biomimetic manufacturing process.

We present a self-assembly method for guiding and positioning nano-and microscale objects onto a template mediated by a genetically engineered polypeptide. We have identified a polypeptide that can specifically recognize and bind to gold via cell surface display and biopanning. We demonstrate that this polypeptide can differentiate between various inorganic materials such as platinum, gold, and silicon dioxide. We have utilized this polypeptide to guide the assembly of nanoscale quantum dots or microscale gold spheres onto patterned microfabricated substrates. Our approach of using the material recognition polypeptides opens a new venue for bridging the organic and inorganic domains and guiding self-assembly of structures and devices from the bottom up.

Adapting molecular biology to materials science we developed peptide-based protocols for the assembly and formation of hybrid materials and systems. In this approach of generating molecular scale biomimetic materials, peptides are designed, synthesized, genetically tailored and, finally, utilized as potential molecular linkers in self-assembly, ordered organization, and fabrication of inorganics for specific technological applications. The potential areas range from molecular and nanoscale functional materials to medical fields, e.g., from diagnosis to biosensors. Here, we describe a selection of inorganic binding polypeptides via directed evolution, post-selection modifications through genetic engineering, and utility in practical applications. The selection of the inorganic binders is accomplished through combinatorial biology based peptide libraries. The diversity of applications is highlighted in three case studies. First, the molecular and nanoscale recognition of the polypeptide is presented via nanosize gold particle immobilization onto a molecular template by gold binding polypeptide. Second, we present that the alkaline phosphatase fused with multiple repeats of gold binding polypeptide can still be enzymatically active when it is immobilized onto a solid substrate. Finally, we present silica biosynthesis in aqueous environment using engineered quartz-binding peptides.

Over the last decade, solid-binding peptides have been increasingly used as molecular building blocks coupling bio- and nanotechnology. Despite considerable research being invested in this field, the effects of many surface-related parameters that define the binding of peptide to solids are still unknown. In the quest to control biological molecules at solid interfaces and, thereby, tailoring the binding characteristics of the peptides, the use of surface charge of the solid surface may probably play an important role, which then can be used as a potential tuning parameter of peptide adsorption. Here, we report quantitative investigation on the viscoelastic properties and binding kinetics of an engineered gold-binding peptide, 3RGBP 1, adsorbed onto the gold surface at different surface charge densities. The experiments were performed in aqueous solutions using an electrochemical dissipative quartz crystal microbalance system. Hydrodynamic mass, hydration state and surface coverage ...

Combinatorially selected peptides and peptide-organic conjugates were used as linkers with controlled structural and organizational conformations to attach quantum dots (QDs) at addressable distances from a metal surface. This study demonstrates an approach towards nanophotonics by integrating inorganic, organic, and biological constructs to form hybrid nanoassemblies through template-directed self-assembly. Peptide-organic-linked QD arrays showed stronger fluorescence than peptide-linked QD arrays. We attribute this difference primarily to the increased number density of QDs on peptide-organic-linked QD arrays.

This study constitutes a demonstration of the biological route to controlled nano-fabrication via modular multi-functional inorganic-binding peptides. Specifically, we use gold-and silica-binding peptide sequences, fused into a single molecule via a structural peptide spacer, to assemble presynthesized gold nanoparticles on silica surface, as well as to synthesize nanometallic particles in situ on the peptide-patterned regions. The resulting film-like gold nanoparticle arrays with controlled spatial organization are characterized by various microscopy and spectroscopy techniques. The described bio-enabled, single-step synthetic process offers many advantages over conventional approaches for surface modifications, self-assembly and device fabrication due to the peptides' modularity, inherent biocompatibility, material specificity and catalytic activity in aqueous environments. Our results showcase the potential of artificially-derived peptides to play a key role in simplifying the assembly and synthesis of multi-material nano-systems in environmentally benign processes.

Self-assembly of proteins on surfaces is utilized in many fields to integrate intricate biological structures and diverse functions with engineered materials. Controlling proteins at bio-solid interfaces relies on establishing key correlations between their primary sequences and resulting spatial organizations on substrates. Protein self-assembly, however, remains an engineering challenge. As a novel approach, we demonstrate here that short dodecapeptides selected by phage display are capable of self-assembly on graphite and form long-range ordered biomolecular nanostructures. Using atomic force microscopy and contact angle studies, we identify three aminoacid domains along the primary sequence that steer peptide ordering and lead to nanostructures with uniformly displayed residues. The peptides are further engineered via simple mutations to control fundamental interfacial processes, including initial binding, surface aggregation and growth kinetics, and intermolecular interactions. Tailoring short peptides via their primary sequence offers versatile control over molecular self-assembly, resulting in well-defined surface properties essential in building engineered, chemically rich, bio-solid interfaces.

Semiconductor nanocrystal quantum dots are utilized in numerous applications in nano-and biotechnology. In device applications, where several different material components are involved, quantum dots typically need to be assembled at explicit locations for enhanced functionality. Conventional approaches cannot meet these requirements where assembly of nanocrystals is usually material-nonspecific, thereby limiting the control of their spatial distribution. Here we demonstrate directed self-assembly of quantum dot emitters at material-specific locations in a color-conversion LED containing several material components including a metal, a dielectric, and a semiconductor. We achieve a spatially selective immobilization of quantum dot emitters by using the unique material selectivity characteristics provided by the engineered solid-binding peptides as smart linkers. Peptide-decorated quantum dots exhibited several orders of magnitude higher photoluminescence compared to the control groups, thus, potentially opening up novel ways to advance these photonic platforms in applications ranging from chemical to biodetection.

The objective of this study was to evaluate the potential of nanofiltration (NF) and ozonation for indirect potable reuse in terms of pharmaceutical residuals. To simultaneously obtain a reasonable retentate volume for further treatment, the tests were performed at a high volume reduction factor (VRF) of 60. The feed to the pilot plant was the effluent from a BNR plant with a final process step of chemical precipitation and rapid sand filtration. Two tests were performed 1) nanofiltration of treated wastewater followed by ozonation and 2) ozonated treated wastewater as feed to NF. Of the 95 pharmaceuticals analysed, three were not removed to the quantification limit, oxazepam in the first test and glibenclamide and ketoprofen in the second. The water quality after the two processes was similar, with an overall removal of pharmaceutical residuals of 99%. There are two advantages of ozonated water as feed to NF—a higher specific flux of 35% and a potential removal of ozonation by-prod...

Theoretical Investigation on the Electronic Structure of Alq3/Al Interface SUSUMU YANAGISAWA, Osaka University, YOSHITADA MORIKAWA, Osaka Univ., RICS-AIST -Alq 3 [tris-(8-hydroxyquinolinato) aluminum] is one of the most widely used electron transport and emissive material in organic light-emitting devices (OLEDs). From the experimental observation of an extra gap state at the Alq 3 /Al interface, a strong chemical interaction between the Alq 3 molecule and the Al surface was suggested. Contrary to the experimental studies, previous DFT calculations concluded that the interaction was physisorptive. One possible reason for the discrepancy between the theoretical and the experimental results is the complexity of the experimentally used electrode surfaces. In the present study, we investigated the effect of the surface roughness on the electronic properties of the Alq 3 /Al interface by examining various possible electrode structures. We examined three structures for the Al substrate, the flat Al(111) surface, the Al(332) stepped surface, and the Al adatom adsorbed Al(111) surface. Alq 3 molecules are bound to Al substrates through their O atoms and about 0.3-0.6 electrons are transferred from the Al substrates to Alq 3 . Upward configurations, in which molecular permanent dipole moments are directed to the vacuum side, reduce the work function by 1.0-1.5 eV, in reasonable agreement with experimental results. The characteristic of the molecular orbitals of Alq 3 were kept upon adsorption, which seems inconsistent with the gap state derived from the interfacial chemical interaction observed in the UPS and MAES experiments. Further details will be presented.