220 research outputs found

    Novel polythiophene derivatives functionalized withconjugated side-chain pendants comprisingtriphenylamine/carbazole moieties for photovoltaic cellapplications†

    Get PDF
    We synthesized a series of polythiophenes (PTs) featuring 2-ethylhexyl-substituted terthiophene (T) orquaterthiophene (BT) as the conjugated unit in the polymer backbone with pendant conjugated tertbutyl-substituted triphenylamine (tTPA)- or carbazole (tCz)-containing moieties as side chains, namelyPTtTPA, PBTtTPA, PTtCz and PBTtCz. Incorporating T and BT moieties into the polymer backbone andattaching tTPA or tCz units promoted efficient conjugation within the extended conjugated frameworksof the polymers, resulting in lower band-gap energies and red-shifting of the maximal UV-Visabsorption wavelength. The higher electron-donating ability of tTPA resulted in broader absorptionbands and lower band-gap energies of PTtTPA and PBTtTPA as compared with PTtCz and PBTtCz.Incorporation of the T and BT moieties into the polymer backbone enhanced the compatibility of PTand the fullerene derivative by reducing the side-chain density of PT, thus providing sufficient freevolume for efficient incorporation of [6,6]phenyl-C61-butyric acid methyl ester (PC61BM) into thepolymer chains. Polymer solar cells (PSCs) were fabricated by spin-coating a blend of each PT with thefullerene derivative (PC61BM) as a composite film-type photoactive layer; PBTtTPA/PC61BM-based PSCsshowed superior photovoltaic (PV) performance to PTtTPA/PC61BM-based PSCs in terms of conjugationand absorption band broadness. However, PBTtCz/PC61BM-based PSCs showed inferior PV performanceto PTtCz/PC61BM-based PSCs. The lower HOMO level led to a higher open-circuit voltage (Voc; 0.74 V)and larger photo-energy conversion efficiency (h; 2.77%) of PTtCz/PC61BM-based PSCs

    An Integrated Multiechelon Logistics Model with Uncertain Delivery Lead Time and Quality Unreliability

    Get PDF
    Nowadays, in order to achieve advantages in supply chain management, how to keep inventory in adequate level and how to enhance customer service level are two critical practices for decision makers. Generally, uncertain lead time and defective products have much to do with inventory and service level. Therefore, this study mainly aims at developing a multiechelon integrated just-in-time inventory model with uncertain lead time and imperfect quality to enhance the benefits of the logistics model. In addition, the Ant Colony Algorithm (ACA) is established to determine the optimal solutions. Moreover, based on our proposed model and analysis, the ACA is more efficient than Particle Swarm Optimization (PSO) and Lingo in SMEIJI model. An example is provided in this study to illustrate how production run and defective rate have an effect on system costs. Finally, the results of our research could provide some managerial insights which support decision makers in real-world operations

    Trends and characteristics of pethidine use in Taiwan: a six-year-long survey

    Get PDF
    OBJECTIVES: To investigate the trends and characteristics of pethidine prescriptions and users in Taiwan from 2002 to 2007. METHOD: All pethidine users (n = 3,301,136) in Taiwan from 2002 to 2007 were linked to National Health Insurance claims to identify pethidine prescriptions. We examined the trends in pethidine user prevalence and the proportion of pethidine prescriptions according to health care characteristics. A logistic regression model was used to compare patient demographics and health care characteristics associated with pethidine prescriptions between 2002 and 2007. RESULTS: Despite the decline in the number of pethidine users and prescriptions over the six-year period, more than half a million people were prescribed pethidine annually. In fact, an increasing proportion of pethidine prescriptions were observed in clinics, outpatient settings, and patients who had both operations and cancer diagnoses. Pethidine prescriptions were mostly associated with a non-operation status without a cancer diagnosis (>;60%). However, approximately 10% of the total pethidine prescriptions were found in patients with a cancer diagnosis but no operation. Compared to those in 2002, pethidine prescriptions in 2007 were more likely to be found in people 80 years or older, rural residents, patients from clinics, outpatient settings and operation patients with cancer diagnoses. CONCLUSIONS: A population-based survey in Taiwan demonstrated decreasing consumption of pethidine from 2002 to 2007; however, an increased proportion of prescriptions in certain health care settings was observed. In addition, 10% of the pethidine prescriptions were for cancer patients without operations. These cases need further evaluation for the determination of appropriate pethidine use

    A Distributed Urban Traffic Congestion Prevention Mechanism for Mixed Flow of Human-Driven and Autonomous Electric Vehicles

    Get PDF
    Traffic congestion in urban areas has become a critical problem that municipal governments cannot overlook. Meanwhile, mixed traffic systems containing both autonomous and human-driven electric vehicles ramp up the challenge for traffic management in urban areas. Although numerous researchers have proposed traffic control heuristics to alleviate traffic congestion problems in the recent literature, scant research has addressed the joint problems of route and charging strategies for electric vehicles along with urban traffic congestion prevention. Accordingly, this work tackles the complex task of traffic management in urban areas during peak periods by using practical congestion prevention strategies that consider the characteristics of mixed traffic flows and the charging demands of electric vehicle users. Notably, we apply support vector regressions to compute the charging time at each charging point and the traverse time of an electric vehicle at each road segment/intersection, based on historical traffic data. The simulation results reveal that the proposed algorithms are feasible because they can avoid possible occurrences of traffic congestion during rush hours and provide the routes and charging options that are chosen by electric vehicle users

    MUC4 gene polymorphisms associate with endometriosis development and endometriosis-related infertility

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Mucin 4 (<it>MUC4</it>) plays an important role in protecting and lubricating the epithelial surface of reproductive tracts, but its role in the pathogenesis of endometriosis is largely unknown.</p> <p>Methods</p> <p>To correlate <it>MUC4 </it>polymorphism with the risk of endometriosis and endometriosis-related infertility, we performed a case-control study of 140 patients and 150 healthy women. Six unique single-nucleotide polymorphisms (SNPs) (rs882605, rs1104760, rs2688513, rs2246901, rs2258447 and rs2291652) were selected for this study. DNA fragments containing the target SNP sites were amplified by polymerase chain reaction using the TaqMan SNP Genotyping Assay System to evaluate allele frequency and distribution of genotype in <it>MUC4 </it>polymorphisms.</p> <p>Results</p> <p>Both the T/G genotype of rs882605 and the frequency of haplotype T-T (rs882605 and rs1104760) were higher in patients than in controls and were statistically significant. The frequency of the C allele at rs1104760, the C allele at rs2688513, the G allele at rs2246901 and the A allele at rs2258447 were associated with advanced stage of endometriosis. Moreover, the G allele at rs882605 was verified as a key genetic factor for infertility in patients. Protein sequence analysis indicated that amino acid substitutions by genetic variations at rs882605, rs2688513 and rs2246901 occur in the putative functional loops and the type D von Willebrand factor (VWFD) domain in the MUC4 sequence.</p> <p>Conclusions</p> <p><it>MUC4 </it>polymorphisms are associated with endometriosis development and endometriosis-related infertility in the Taiwanese population.</p

    Trypsin-induced proteome alteration during cell subculture in mammalian cells

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>It is essential to subculture the cells once cultured cells reach confluence. For this, trypsin is frequently applied to dissociate adhesive cells from the substratum. However, due to the proteolytic activity of trypsin, cell surface proteins are often cleaved, which leads to dysregulation of the cell functions.</p> <p>Methods</p> <p>In this study, a triplicate 2D-DIGE strategy has been performed to monitor trypsin-induced proteome alterations. The differentially expressed spots were identified by MALDI-TOF MS and validated by immunoblotting.</p> <p>Results</p> <p>36 proteins are found to be differentially expressed in cells treated with trypsin, and proteins that are known to regulate cell metabolism, growth regulation, mitochondrial electron transportation and cell adhesion are down-regulated and proteins that regulate cell apoptosis are up-regulated after trypsin treatment. Further study shows that bcl-2 is down-regulated, p53 and p21 are both up-regulated after trypsinization.</p> <p>Conclusions</p> <p>In summary, this is the first report that uses the proteomic approach to thoroughly study trypsin-induced cell physiological changes and provides researchers in carrying out their experimental design.</p

    Real-Time Telemetry System for Amperometric and Potentiometric Electrochemical Sensors

    Get PDF
    A real-time telemetry system, which consists of readout circuits, an analog-to-digital converter (ADC), a microcontroller unit (MCU), a graphical user interface (GUI), and a radio frequency (RF) transceiver, is proposed for amperometric and potentiometric electrochemical sensors. By integrating the proposed system with the electrochemical sensors, analyte detection can be conveniently performed. The data is displayed in real-time on a GUI and optionally uploaded to a database via the Internet, allowing it to be accessed remotely. An MCU was implemented using a field programmable gate array (FPGA) to filter noise, transmit data, and provide control over peripheral devices to reduce power consumption, which in sleep mode is 70 mW lower than in operating mode. The readout circuits, which were implemented in the TSMC 0.18-μm CMOS process, include a potentiostat and an instrumentation amplifier (IA). The measurement results show that the proposed potentiostat has a detectable current range of 1 nA to 100 μA, and linearity with an R2 value of 0.99998 in each measured current range. The proposed IA has a common-mode rejection ratio (CMRR) greater than 90 dB. The proposed system was integrated with a potentiometric pH sensor and an amperometric nitrite sensor for in vitro experiments. The proposed system has high linearity (an R2 value greater than 0.99 was obtained in each experiment), a small size of 5.6 cm × 8.7 cm, high portability, and high integration

    Magnetic Particle-Based Hybrid Platforms for Bioanalytical Sensors

    Get PDF
    Biomagnetic nano and microparticles platforms have attracted considerable interest in the field of biological sensors due to their interesting physico-chemical properties, high specific surface area, good mechanical stability and opportunities for generating magneto-switchable devices. This review discusses recent advances in the development and characterization of active biomagnetic nanoassemblies, their interaction with biological molecules and their use in bioanalytical sensors
    corecore