212 research outputs found

    Monolithic silicon opto-electro-mechanical light modulator

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    A Fabry-Perot light beam modulator of the reflection-type has been designed with process and performance parameters optimized. This design takes advantage of the economies of surface micromaching using silicon substrates and selected thin films. High performance with a low drive voltage are achieved using electrostatic actuation of a thin polysilicon diaphragm. The diaphragm is a novel corrugated structure which has maximum compliance and maintains planarity during actuation. In addition, the corrugationsuspension used provides an improved linearity of amplitude modulation response as a function of the actuation voltage. A preliminary version of this device has been fabricated through a contract foundry using some industry- standard film thicknesses. The preliminary version of the device confirms the physical mask design without optimal film processing. The optimized Fabry-Perot structure is designed for operation at a wavelength of 1.3 nm. Using a thin, corrugated diaphragm of 190 nm thickness a 48.90% modulation index is obtained with an actuation voltage of 5 volts based on detailed simulation results. The final optimized device will be fabricated at NJIT at a future date. The proposed optimized device contains a titanium-tungsten metal film deposited into a cavity of half wavelength depth and insulated from the monolithic silicon substrate. An additional quarter wavelength film of silicon nitride is deposited over the metal to increase the modulation index. In the fabrication process a 325 nm sacrificial film of spinon glass is deposited to fill the cavity and form the spacer between the Fabry-Perot etalon entrance and reflecting surfaces. The optical entrance surface is obtained next in the fabrication process by depositing an infrared-transmissive film of polysilicon. The selected polysilicon thickness is 190 nm or any odd integer multiple of a half wavelength. This device can be used as an economical light modulator in near-infrared communications and control systems. This device suitable for relatively low bandwidth applications is expected to provide cost and reliability advantages over competing torsion mirror and macro-sized modulators

    Antiosteoporotic Activity of Dioscorea alata L. cv. Phyto through Driving Mesenchymal Stem Cells Differentiation for Bone Formation

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    The aim of this study was to evaluate the effect of an ethanol extract of the rhizomes of Dioscorea alata L. cv. Phyto, Dispo85E, on bone formation and to investigate the mechanisms involved. Our results showed that Dispo85E increased the activity of alkaline phosphatase (ALP) and bone nodule formation in primary bone marrow cultures. In addition, Dispo85E stimulated pluripotent C3H10T1/2 stem cells to differentiate into osteoblasts rather than adipocytes. Our in vivo data indicated that Dispo85E promotes osteoblastogenesis by increasing ALP activity and bone nodule formation in both intact and ovariectomized (OVX) mice. Microcomputed tomography (μCT) analysis also showed that Dispo85E ameliorates the deterioration of trabecular bone mineral density (tBMD), trabecular bone volume/total volume (BV/TV), and trabecular bone number (Tb.N) in OVX mice. Our results suggested that Dispo85E is a botanical drug with a novel mechanism that drives the lineage-specific differentiation of bone marrow stromal cells and is a candidate drug for osteoporosis therapy

    Whole-body vibration training effect on physical performance and obesity in mice

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    The purpose of this study was to verify the beneficial effects of whole-body vibration (WBV) training on exercise performance, physical fatigue and obesity in mice with obesity induced by a high-fat diet (HFD). Male C57BL/6 mice were randomly divided into two groups: normal group (n=6), fed standard diet (control), and experimental group (n=18), fed a HFD. After 4-week induction, followed by 6-week WBV of 5 days per week, the 18 obese mice were divided into 3 groups (n=6 per group): HFD with sedentary control (HFD), HFD with WBV at relatively low-intensity (5.6 Hz, 0.13 g) (HFD+VL) or high-intensity (13 Hz, 0.68 g) (HFD+VH). A trend analysis revealed that WBV increased the grip strength in mice. WBV also dose-dependently decreased serum lactate, ammonia and CK levels and increased glucose level after the swimming test. WBV slightly decreased final body weight and dose-dependently decreased weights of epididymal, retroperitoneal and perirenal fat pads and fasting serum levels of alanine aminotransferase, CK, glucose, total cholesterol and triacylglycerol. Therefore, WBV could improve exercise performance and fatigue and prevent fat accumulation and obesity-associated biochemical alterations in obese mice. It may be an effective intervention for health promotion and prevention of HFD-induced obesity

    RINGdb: An integrated database for G protein-coupled receptors and regulators of G protein signaling

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    BACKGROUND: Many marketed therapeutic agents have been developed to modulate the function of G protein-coupled receptors (GPCRs). The regulators of G-protein signaling (RGS proteins) are also being examined as potential drug targets. To facilitate clinical and pharmacological research, we have developed a novel integrated biological database called RINGdb to provide comprehensive and organized RGS protein and GPCR information. RESULTS: RINGdb contains information on mutations, tissue distributions, protein-protein interactions, diseases/disorders and other features, which has been automatically collected from the Internet and manually extracted from the literature. In addition, RINGdb offers various user-friendly query functions to answer different questions about RGS proteins and GPCRs such as their possible contribution to disease processes, the putative direct or indirect relationship between RGS proteins and GPCRs. RINGdb also integrates organized database cross-references to allow users direct access to detailed information. The database is now available at . CONCLUSION: RINGdb is the only integrated database on the Internet to provide comprehensive RGS protein and GPCR information. This knowledgebase will be useful for clinical research, drug discovery and GPCR signaling pathway research

    A Model of Technological Imagination and Creativity: Cognitive Task Analysis

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    An integrated model of cognitive tasks involved in the process of a technological innovation was proposed based on these theories: 1. CDIO theory of technological innovation, 2. Wallas’s creative thinking processes, 3. Khalr & Simon’s theory of scientific discovery, and 4. the conceptual combination theory of imagination. The central theme of this model is the proposition that three cognitive conditions are necessary for technological imagination and innovation: 1. cross-domain knowledge, 2. simple heuristics, and 3. pattern recognition ability. Although the required domain knowledge and implementation methods are different across domains, heuristics that lead to a breakthrough at each phase of CDIO in a technological innovation are similar, with conceptual combination as the cognitive engine for generating original and imaginative ideas

    Mineralization of Progenitor Cells with Different Implant Topographies

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    AbstractThe major challenge for dental implants is achieving an optimal osteoregeneration. Different levels of roughness processed through sand-blasting/ acid-etching (SLA) then further treated with silane and peptide were measured. Peptide bonded with silane on the SLA and machine ground titanium (Ti) surface were used as a culture substitute. The sample properties on the osteogenic abilities were compared by testing the interaction with mesenchymal stem cells (MSCs, D1). When comparing to the SLA only group, the silane treated Ti surface with peptide bonded had smaller wetting angle and the cell proliferative ability did differ with statistical significance (p<0.05). A rougher surface binding with peptide provided higher hydrophilic ability and had the potential ability to enhance the proliferation and mineralization of the progenitor cell D1. Accordingly, a novel implant surface treatment method having tissues integrated was obtained through the supplement of peptide on the surfaces through SLA treatment of titanium

    Pleural Effusion after Percutaneous Radiofrequency Ablation for Hepatic Malignancies

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    AbstractBackground and AimsRadiofrequency ablation (RFA) can play an important role in the treatment of primary or metastatic liver tumors. Currently, percutaneous RFA is generally regarded as a safe, effective, and minimally invasive procedure. This study aimed to evaluate the presence and course of pleural effusion after monopolar RFA.MethodsFrom October 2008 to July 2013, a total of 54 patients (28 male and 26 female, mean age 65.2) treated with monopolar RFA were included in our study. 47 patients were diagnosed with hepatocellular carcinoma, 4 patients with hepatic metastasis, and 3 patients had other diagnoses. There were a total of 115 sessions of treatment and 199 liver tumors to be treated (1.73 ± 1.02 tumors treated per session). The tumor size ranged from 0.8 cm to 5.0 cm (mean 2.31 cm, standard deviation 1.04 cm). Thereafter, a follow-up ultrasound was performed within 24 hours subsequent to ablation to evaluate the presence of pleural effusion. The degree of pleural effusion was assessed by chest X-ray.ResultsFifteen (13.0%) treatment sessions in 14 patients showed right-sided pleural effusion after ablations. One patient had a large amount of effusion, while other patients manifested a minimal to small amount of effusion. There were 5 patients that experienced delayed resolution of pleural effusion; one patient (0.87%) had a minimal amount of pleural effusion even after one month. Overall, there was no pneumothorax, or periprocedural morality. Age, gender, tumor numbers, tumor sizes, and complete ablation of target tumors were similar among groups presenting with or without pleural effusion. Tumor locations associated with S78 segments abutting the diaphragm or right lobe of the liver were not associated with development of pleural effusion. Only the duration of ablation time had a marginal trend toward significance (p = 0.051).ConclusionsThe transient appearance of right-sided pleural effusion after percutaneous RFA for hepatic malignancies was not infrequent. However, refractory pleural effusion was rare

    Natural Product Chemistry of Gorgonian Corals of Genus Junceella—Part II

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    The structures, names, bioactivities, and references of 81 new secondary metabolites obtained from gorgonian corals belonging to the genus Junceella are described in this review. All compounds mentioned in this review were obtained from sea whip gorgonian corals Junceella fragilis and Junceella juncea, collected from the tropical and subtropical Indo-Pacific Ocean
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