Label-free sugar detection using phenylboronic acid-functionalized piezoresistive microcantilevers

By appropriate surface functionalization using a thiolated phenylboronic acid derivative, gold-coated piezoresistive microcantilevers responsive to analytes having vicinal cis-diols were fashioned. A reference, uncoated cantilever permitted reliable subtraction of background signal (i.e., differential measurement). Experiments carried out in static mode under flow conditions, using the monosaccharide D-(-)-fructose as a test analyte in aqueous buffer, showed that the measured stationary-state surface stress was linear in analyte concentration over the 0-25 mM range, allowing this sugar to be readily detected at physiologically meaningful concentrations and at neutral pH. This approach offers a simple, reagentless, and flexible format for polyol screening that does not require aqueous alkaline solutions, suggesting potential applications in biomass process monitoring and glucose assay.     

Fabrication and characterization of electrospun titania nanofibers

Titania (TiO₂) nanofibers were fabricated by electrospinning three representative spin dopes made of titanium (IV) n-butoxide (TNBT) and polyvinylpyrrolidone (PVP) with the TNBT/PVP mass ratio being 1/2 in three solvent systems including N,N-dimethylformamide (DMF), isopropanol, and DMF/isopropanol (1/1 mass ratio) mixture, followed by pyrolysis at 500 °C. The detailed morphological and structural properties of both the as-electrospun precursor nanofibers and the resulting final TiO₂ nanofibers were characterized by SEM, TEM, and XRD. The results indicated that the precursor nanofibers and the final TiO₂ nanofibers made from the spin dopes containing DMF alone or DMF/isopropanol mixture as the solvent had the common cylindrical morphology with diameters ranging from tens to hundreds of nanometers, while those made from the spin dope containing isopropanol alone as the solvent had an abnormal concave morphology with sizes/widths ranging from sub-microns to microns. Despite the morphological discrepancies, all precursor nanofibers were structurally amorphous without distinguishable phase separation, while all final TiO₂ nanofibers consisted of anatase-phased TiO₂ single-crystalline grains with sizes of approximately 10 nm. The electrospun TiO₂ nanofiber mat is expected to significantly outperform other forms (such as powder and film) of TiO₂ for the solar cell (particularly dye-sensitized solar cell) and photo-catalysis applications.     

Evaluation of the Central Effects of Systemic Lentiviral-Mediated Leptin Delivery in Streptozotocin-Induced Diabetic Rats

Type 1 diabetes (T1D) is characterized by hyperphagia, hyperglycemia and activation of the hypothalamic–pituitary–adrenal (HPA) axis. We have reported previously that daily leptin injections help to alleviate these symptoms. Therefore, we hypothesized that leptin gene therapy could help to normalize the neuroendocrine dysfunction seen in T1D. Adult male Sprague Dawley rats were injected i.v. with a lentiviral vector containing the leptin gene or green fluorescent protein. Ten days later, they were injected with the vehicle or streptozotocin (STZ). HPA function was assessed by measuring norepinephrine (NE) levels in the paraventricular nucleus (PVN) and serum corticosterone (CS). Treatment with the leptin lentiviral vector (Lepvv) increased leptin and insulin levels in non-diabetic rats, but not in diabetic animals. There was a significant reduction in blood glucose levels in diabetic rats due to Lepvv treatment. Both NE levels in the PVN and serum CS were reduced in diabetic rats treated with Lepvv. Results from this study provide evidence that leptin gene therapy in STZ-induced diabetic rats was able to partially normalize some of the neuroendocrine abnormalities, but studies with higher doses of the Lepvv are needed to develop this into a viable option for treating T1D.     

Ground penetrating radar (GPR) study to detect seepage pathways in the Ajanta Caves in India

The present study used the ground penetrating radar (GPR) tool to decipher the presence of fractures which may be possible pathways for seepage into the Ajanta Caves in India. GPR data were collected by 40- and 200-MHz antennas from Geophysical Survey Systems, Inc. (GSSI). The data were edited and processed using the RADAN 6.5 software. The processed data indicate the presence of fractures of varying orientation in the basaltic formations. The study shows high reflection zones indicative of fractures as well as strong absorbance zones which may be a homogeneous zone without any fractures.     

Narrow and wide band monopole antenna design using heterogeneous bidirectional recurrent neural network for LTE and UWB applications

The proposed antenna is a small wideband monopole with wideband circular polarization using heterogeneous bidirectional recurrent neural network for both narrow and wide band applications (NWB-MAD-HBRNN). The electromagnetic structure is designed, fabricated, and simulated with 1 mm thickness on FR4 substrate material along dielectric constant 4.3. The proposed antenna includes 4.3–8.85 GHz for ultrawideband applications; it contains reconfigurable narrow band for L-band 1.27 GHz, LTE, and ultrawideband applications. To enhance the antenna impedance bandwidth (BW) along axial ratio bandwidth (ARBW), a slit is etched at the antenna patch, a rectangular stub is inserted into the ground plane, and semicircular stub is added to the top of antenna feed line. The better agreement is observed in the measured and simulated gain performance of 4.8 dB for LTE band applications. The proposed NWB-MAD-HBRNN design provides 13.50%, 18.91%, and 22.58% higher bandwidth and 18.36%, 20.38%, and 27.58% lower return loss than the existing designs, such as bio-inspired wideband antenna for wireless applications based on perturbation technique (BWA-WA-PA), a compact circularly polarized modified printed monopole antenna for wireless applications (CCP-MPMA-WA), and new multiband monopole antenna for certain broadband wireless applications along wireless personal communications (PA-MMA-BWA), respectively.     

使用双变压器配置时宽带ADC前端设计

变压器用于信号隔离,并且将单端信号转换成差分信号。当在高速模数转换器(ADC)前端电路中使用变压器时常常忽略的一个问题是变压器绝非理想器件。任何由变压器引起的输入失衡都会使输入的正弦信号变成非理想的正弦信号波形传送给ADC的输入端,从而导致ADC的总体性能不如其它方式耦合到ADC的性能。本文讨论了变压器的输入失衡对ADC性能造成的影响,并且提供了改进电路的实例。1变压器制造商提供的多种多样的型号给变压器选择造成混乱。规定性能的供应商所采用的不同方法将问题复杂化;它们通常在选择和定义其规定的参数方面都不相同。当选…     

Hydrogen production by alcoholysis of sodium borohydride

Alcoholysis of sodium borohydride offers advantages due to reduction in number of steps for recycling of sodium borohydride, elimination of freezing problems that are associated with the use of water, fast generation of hydrogen, etc. Methanol was used to liberate hydrogen from sodium borohydride. The influence of the amount of solvent, substrate concentration, temperature and catalyst on the kinetics of alcoholysis reaction in non‐stabilized sodium borohydride has been examined in the present study. The reaction was found to be first order with respect to substrate concentration and zero order with respect to solvent concentration. Effect of soluble metal salts, metal powder and metal boride as catalysts on hydrogen generation rate has also been investigated. It was found that NiCl₂, Ni₂B and RuCl₃ were effective catalysts and hydrogen generation proceeds with high efficiency in the presence of these catalysts. Copyright © 2013 John Wiley & Sons, Ltd.     

AMZ Driverless: The full autonomous racing system

This paper presents the algorithms and system architecture of an autonomous racecar. The introduced vehicle is powered by a software stack designed for robustness, reliability, and extensibility. To autonomously race around a previously unknown track, the proposed solution combines state of the art techniques from different fields of robotics. Specifically, perception, estimation, and control are incorporated into one high‐performance autonomous racecar. This complex robotic system, developed by AMZ Driverless and ETH Zürich, finished first overall at each competition we attended: Formula Student Germany 2017, Formula Student Italy 2018 and Formula Student Germany 2018. We discuss the findings and learnings from these competitions and present an experimental evaluation of each module of our solution.     

Squirrel Search Algorithm Based Support Vector Machine for Congestion Control in WSN-IoT

Wireless Personal Communications - As the Wireless sensor network (WSN) has huge part in Internet of Things (IoT), it is used in different applications, for example, detecting climate and sending...