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Highlights • Organic vapor phase deposition of perylene diimide monolayers significantly reduces surface recombination of InP wafers. • Conformal coating allows for passivation of 3D surfaces such as mesas. • Passivation leads to improved photoconductivity in InP detectors. Abstract We demonstrate the surface passivation of InP using thin layers of a perylenetetracarboxylic diimide derivative (PTCDI-C 9) applied via organic vapor phase deposition (OVPD). The organic layer forms a conformal crystalline film on the InP surface, which is confirmed by atomic force microscopy and X-ray diffraction. Area-dependent photoluminescence measurements indicate that the coating reduces surface recombination. The organic thin film deposited by OVPD exhibits improved photoconductivity compared to an unpassivated InP sample, and to a layer deposited via vacuum thermal evaporation. Our results suggest that semiconductor surface passivation using organic thin films deposited by OVPD has applications to a variety of optoelectronic devices, particularly with structures requiring sidewall or conformal coatings. [ABSTRACT FROM AUTHOR]

Mesenchymal stromal cells (MSCs) continue to be proposed for use in clinical trials to treat various diseases due to their therapeutic potential to pleiotropically influence endogenous regenerative processes, such as vasculogenesis. However, the functional heterogeneity of MSCs has hampered their clinical success and poses a significant manufacturing challenge with respect to MSC quality control. Here, we evaluated and qualified a quantitative bioassay based on an enhanced-throughput, microphysiological system to measure the specific paracrine bioactivity of MSCs to stimulate vasculogenesis as a measure of MSC potency. Using this novel bioassay, MSCs derived from multiple donors at different passages were co-cultured with human umbilical vein endothelial cells (HUVECs) and exhibited significant heterogeneity in vasculogenic potency between donors and cell passage. Using our microphysiological system (MPS)-based platform, we demonstrated that variations in MSC vasculogenic bioactivity were maintained when assayed across laboratories and operators. The differences in MSC vasculogenic bioactivity were also correlated with the baseline expression of several genes involved in vasculogenesis (hepatocyte growth factor (HGF), angiopoietin-1 (ANGPT)) or the production of matricellular proteins (fibronectin (FN), insulin-like growth factor-binding protein 7 (IGFBP7)). These findings emphasize the significant functional heterogeneity of MSCs in vasculogenic bioactivity and suggest that changes in baseline gene expression of vasculogenic or matricellular protein genes during manufacturing may affect this bioactivity. The development of a reliable and functionally relevant potency assay for measuring the specific vasculogenic bioactivity of manufactured MSCs will help to reliably assure their quality when used in appropriate clinical trials. [ABSTRACT FROM AUTHOR]

Support Vector Machine (SVM) is an efficient machine learning technique applicable to various classification problems due to its robustness. However, its time complexity grows dramatically as the number of training data increases, which makes SVM impractical for large-scale datasets. In this paper, a novel Parallel Hyperplane (PH) scheme is introduced which efficiently omits redundant training data with SVM. In the proposed scheme the PHs are recursively formed while the clusters of data points outside the PHs are removed at each repetition. Computer simulation reveals that the proposed scheme greatly reduces the training time compared to the existing clustering-based reduction scheme and SMO scheme, while allowing the accuracy of classification as high as no data reduction scheme. [ABSTRACT FROM AUTHOR]

As flash memory becomes popular, flash memory-based solid-state drive (SSD) has been the major storage device. SSD has numerous merits such as high I/O speed, low energy consumption, strong shock resistance and small form factor. Meanwhile, some shortcomings still exist including erase-before-write and different cost for read, write and erase operation. Aiming at efficient buffer management of SSD, this paper proposes a novel approach based on particle swarm optimization (PSO) algorithm. The PSO algorithm is used to estimate the Predict Hot Fitness value of each logical page in the buffer to correctly identify them either as hot or cold by properly reflecting the spatial and temporal locality. The pages predicted as hot are kept in the buffer to maximize the hit ratio and utilization of the SSD buffer. Simulation with real workload shows that the proposed scheme significantly outperforms the representative SSD buffer management schemes in terms of hit ratio and throughput. [ABSTRACT FROM AUTHOR]

The extraction of large common bile duct (CBD) stones after an endoscopic sphincterotomy is successful in most cases. However, the procedure often requires a prolonged time and repeated trials, therefore, subsequent occurrence of procedure-related complications are not uncommon. The purpose of the present paper was to investigate the utility of a combined endoscopic papillary large balloon dilation (EPLBD) preceded by a mid-incision endoscopic sphincterotomy for the removal of large CBD stones. Stone removal was surprisingly effective with EPLBD in patients with large CBD stones. Occurrence of major complication, such as pancreatitis, bleeding, and perforation, was not observed in any patients who were treated with EPLBD. EPLBD also can be safely carried out on patients with anatomic alteration, such as a periampullary diverticulum, and on patients who have undergone a Billroth II operation. EPLBD is a landmark method of removing a large CBD stone, the impact of which is comparable to that of the introduction of endoscopic mechanical lithotripsy. However, further investigation is required to address the applications and potential outcomes of this procedure. Also, procedure guidelines should be established to avoid major complications. [ABSTRACT FROM AUTHOR]

In this review, we highlight the properties, functions and applications of stimuli-responsive hydrogel patterns in bioanalytical applications. Stimuli-responsive hydrogel patterns can be realized by well-established micro- and nanofabrication technologies such as photolithography and micromolding, and are currently adopted as active components for manipulation of flow and biosamples in microchannel and microarray systems. We overview the properties of stimuli-responsive hydrogel materials and their fabrication methods along with some representative examples in microfluidics and microarrays. [ABSTRACT FROM AUTHOR]

Skin rejuvenation is the most popular topic in cosmetic industry. Recently, skin phototherapy is spotlighted among a lot of skin therapies by its advantageous effects and ease of use. Phototherapy has been widely used for cosmeceutical purposes such as anti-aging or anti-bacterial effects. By the optical properties of light, however, the visible lights cannot reach deep inside the skin layer by reflection and scattering at the outermost boundary of the skin, the stratum corneum and epidermis. This paper describes new method to improve the skin phototherapy using microneedles. We used microneedle as the light transporter like optic fiber to transport light inside the skin by total internal reflection. The total internal reflection inside microneedles was geometrically analyzed and was measured microscopically. The light transmittance with or without a microneedle array was measured using an optical microscope system. Three different ranges of lights (red, green, blue) were exposed on the backside of the microneedle and the light pass through the microneedles. As the results, using microneedles, light transmissivity was dramatically improved even the shorter wavelength of the light (Blue light). Collaboration of phototherapy and microneedle will be a powerful cosmetic and medical tool for skin therapy. [ABSTRACT FROM AUTHOR]

A letter to the editor on a case of 69-year-old woman with right upper quadrant abdominal pain and febrile sense is presented.

Recent work has demonstrated record-high thermophotovoltaic efficiency using thin-film InGaAs cells, but the power density of devices remains low. Elevated power densities are relevant to many thermophotovoltaic (TPV) applications, ranging from mobile generators to stationary energy storage of renewable electricity, and require effective management of heat and charge carriers. Here we investigate the use of single-junction InGaAs airbridge cells (ABCs) under such conditions. Experimental characterization of an InGaAs ABC with varying emitter and cell temperature is used to develop a predictive device model where carrier lifetimes and series resistances are the sole fitting parameters. The utility of this model is demonstrated through its use in identifying near-term opportunities for improving performance at elevated power densities, and for designing a thermal management strategy that maximizes overall power output. After accounting for the power necessary to cool the cells, this model shows that an InGaAs ABC with high material quality can reach a peak efficiency of ∼41% at 0.5 W/cm2, corresponding to an emitter temperature of 1070 °C, and sustain efficiencies above 36% up to 1.5 W/cm2. • Current airbridge TPV cells are limited by recombination, series resistance, and cell heating. • Improved material quality largely addresses recombination and series resistance losses. • An air-cooled design is proposed for thermal management. • A 41%-efficient TPV cell at 0.5 W/cm2 is predicted based on above improvements. [ABSTRACT FROM AUTHOR]