An In-Line photonic biosensor for monitoring of glucose concentrations

This paper presents two PDMS photonic biosensor designs that can be used for continuous monitoring of glucose concentrations. The first design, the internally immobilized sensor, consists of a reactor chamber, micro-lenses and self-alignment structures for fiber optics positioning. This sensor design allows optical detection of glucose concentrations under continuous glucose flow conditions of 33 μL/h based on internal co-immobilization of glucose oxidase (GOX) and horseradish peroxidase (HRP) on the internal PDMS surface of the reactor chamber. For this design, two co-immobilization methods, the simple adsorption and the covalent binding (PEG) methods were tested. Experiments showed successful results when using the covalent binding (PEG) method, where glucose concentrations up to 5 mM with a coefficient of determination (R2) of 0.99 and a limit of detection of 0.26 mM are detectable. The second design is a modified version of the internally immobilized sensor, where a microbead chamber and a beads filling channel are integrated into the sensor. This modification enabled external co-immobilization of enzymes covalently onto functionalized silica microbeads and allows binding a huge amount of HRP and GOX enzymes on the microbeads surfaces which increases the interaction area between immobilized enzymes and the analyte. This has a positive effect on the amount and rate of chemical reactions taking place inside the chamber. The sensor was tested under continuous glucose flow conditions and was found to be able to detect glucose concentrations up to 10 mM with R2 of 0.98 and a limit of detection of 0.7 mM. Such results are very promising for the application in photonic LOC systems used for online analysis © 2014 by the authors; licensee MDPI, Basel, Switzerland.This work has been funded by the German Research Foundation (DFG) within the framework of the Research Unit 856 Microsystems for Particulate Life-Science Products. One of the authors (S.B.) gratefully acknowledges the financial support of the Volkswagen Foundation. We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)Peer Reviewe

New approaches and algorithms for the analysis of vertical refractivity profile below 1 KM in a subtropical region

YesIn this paper, 17 years of high resolution surface and radiosonde meteorological data from 1997-2013 for the subtropical Gulf region are analysed. Relationships between the upper air refractivity, Nh, and vertical refractivity gradient, ΔN, in the low troposphere and the commonly available data of surface refractivity, Ns are investigated. A new approach is discussed to estimate Nh and ΔN from the analysis of the dry and wet components of Ns, which gives better results for certain cases. Results are compared with those obtained from existing linear and exponential models in the literature. The investigation focusses on three layer heights at 65 m, 100 m and 1 km above ground level. Correlation between the components of Ns with both Nh and ΔN are studied for each atmospheric layer. Where high correlations were found, empirical models are derived from best-fitting curves

Electronic Switch Arrays for Managing Microbattery Arrays

Integrated circuits have been invented for managing the charging and discharging of such advanced miniature energy-storage devices as planar arrays of microscopic energy-storage elements [typically, microscopic electrochemical cells (microbatteries) or microcapacitors]. The architecture of these circuits enables implementation of the following energy-management options: dynamic configuration of the elements of an array into a series or parallel combination of banks (subarrarys), each array comprising a series of parallel combination of elements; direct addressing of individual banks for charging/or discharging; and, disconnection of defective elements and corresponding reconfiguration of the rest of the array to utilize the remaining functional elements to obtain the desited voltage and current performance. An integrated circuit according to the invention consists partly of a planar array of field-effect transistors that function as switches for routing electric power among the energy-storage elements, the power source, and the load. To connect the energy-storage elements to the power source for charging, a specific subset of switches is closed; to connect the energy-storage elements to the load for discharging, a different specific set of switches is closed. Also included in the integrated circuit is circuitry for monitoring and controlling charging and discharging. The control and monitoring circuitry, the switching transistors, and interconnecting metal lines are laid out on the integrated-circuit chip in a pattern that registers with the array of energy-storage elements. There is a design option to either (1) fabricate the energy-storage elements in the corresponding locations on, and as an integral part of, this integrated circuit; or (2) following a flip-chip approach, fabricate the array of energy-storage elements on a separate integrated-circuit chip and then align and bond the two chips together

To Be Ethical Or Not To Be: An International Code Of Ethics For Leadership

To be ethical or not to be that is the question? Leadership is about setting the right example and making a difference in people's lives. You do not have to do great things to make a difference (Ayres, 2004). Honesty, tell the truth no matter what, respect, punctuality, not judgmental, just, humble, and dignity can be international code of ethics every leader should follow. Much has changed in our world in the past several decades including people’s beliefs of what is right and wrong. Have their ethics changed as well? This paper introduces an international code of ethics that can guide all different international leadership styles. What is the definition of Ethical Leadership? How can we introduce an international code of ethics for leadership? Finally, leadership is all about example. While an extensive review of literature was not conducted, this researcher was unable to identify an international code of ethics for leadership. Consequently, it is the opinion of this researcher that the following leader characteristics may apply beyond international and cultural boundaries in most instances— honesty, tell the truth no matter what, respect, punctuality, not judgmental, just, humble, and dignity

Green synthesis, characterization and biofunctionalisation of nanoparticles for medical applications

In the presented work, the phytochemicals existent in the aqueous extract of (Hypericum perforatum L.) St. John's wort was harnessed to prepare silver nanoparticles. Many conditions have been tried and changed until we reached the final protocol, through which we obtained the desired nanoparticles in terms of size, shape and effectiveness. The organic compounds present in the St. John's wort plant played an important role in reducing the silver ions in the solution to metallic silver, as well as in protecting the formed silver nanoparticles in nano dimensions and preventing them from growing to millimeter dimensions by forming a protective layer on the surfaces of these nanoparticles and finally maintaining the stability of these formed nanoparticles in colloidal solutions. This green chemistry approach for the preparation of AgNPs is a simple, safe, sustainable, credible and eco-friendly protocol and the resulting silver nanoparticles are considered promising for later application in the treatment of various infectious and non-communicable diseases. green synthesized silver nanoparticles have been characterized using various techniques such as ultraviolet-visible spectroscopy (UV-Vis), dynamic light scattering (DLS), zeta potential, Fourier transform infrared (ATR-FTIR) spectroscopy, X-Ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), energy dispersive X-Ray (EDX), nanoparticle tracking analysis (NTA), atomic force microscopy (AFM), thermogravimetric analysis (TGA) and atomic absorption spectroscopy (AAS), and all results proved that biosynthesized silver nanoparticles are spherical in shape, stable in colloidal solution, the size of their particles ranges between 20 to 50 nm, have a face-centered cubic (fcc) and crystalline in nature and on the surfaces of these particles, there is a protective layer consisting of a group of St. John's wort compounds, the percentage of which varies according to the number of washing times. It is known that reducing agents and the chemical composition of nanoparticle surfaces are the most influential factors in determining the activity and toxicity of these nanoparticles later because they affect cellular uptake, biodistribution, penetration into biological barriers and the resulting therapeutic effects. Therefore, the second objective of this study was to identify the organic compounds from the aqueous extract of the St. John’s wort, which is present on the surfaces of silver nanoparticles as a protective agent. To achieve this goal, it was necessary to analyze the plant itself, i.e. develop a protocol in HPLC to separate the components of the extracts for this plant well. The aerial parts of the plant were extracted using 8 different solvents. A simple protocol has been developed to obtain isolated peaks in the HPLC spectrum. Detection was carried out at 260 for phloroglucinols (Hyperforin and derivates), 350 for Flavonols and 590 nm for naphthodianthrones (Hypericins). Various standards were selected for this, which also represent the most important and best-known compounds of St. John's wort and the mass spectrometric analysis in positive ion mode was performed to allow in-line analysis coupled directly to the HPLC system used for the separation of the molecular ions according to mass to charge (m/z). Finally, the major ingredients (Hyperforin, Adhyperforin, Hypericin, Rutin, Quercetin, Quercitrin, Quercitrin-hydrate, Hyperoside, Biapigenin and Chlorogenic acid) have been identified. Total phenolic, antioxidant activity (DPPH and ABTS assays.) and their relationship for different extracts were also presented in this study. In another study, the layer on the surfaces of silver nanoparticles was isolated using a mixture of solvents and following a specific protocol. After that, LC–ESI-Q-TOF–MS/MS analysis was carried out to determine these substances, and they have already been identified, which are 1=Neochlorogenic acid; 2=Hyperoside; 3=Isoquercitrin; 4=l3,II8-biapigenin; 5=Furohyperforin; 6= Hyperforin; 7=Furoadhyperforin; 8=Adhyperforin. Antioxidant activity of the biologically prepared AgNPs was studied using 3 different methods: DPPH, ABTS and SO assays, and the results were very impressive and better than all that was mentioned by other researchers. The antimicrobial effect on about 20 types of microbes (Gram-positive bacteria, Gram-negative bacteria, Pathogenic yeast and leishmaniasis tropica Syrian strain (LT_SYR_24)) has been studied in multiple areas and using different methods. In fact, the results were very excellent compared to antibiotics, silver nitrate, as well as silver nanoparticles prepared by other researchers, as they were mostly lethal at very low concentrations. Anti-cancer activity against 3 types (Hela, Hep G2 and A549 cells) at various concentrations and various exposure times, and the results were very distinctive and promising for use as a future treatment for cancer. After the prepared silver nanoparticles achieved great success in treating different types of cancer cells, the last and most important step was how to modify these particles to be selectivity, that is, when injected in vivo, they go directly to the tumor or cancer cells without affecting healthy cells. Since oligonucleotide-based aptamers (APTs) are excellent ligands for targeting cancer cells, we have already developed a special protocol to conjugate silver nanoparticles prepared in our method with a specific aptamer as a selective targeting part for uptake by A549 cells. Many conditions and factors have been tried to reach a high coupling ratio without affecting the effectiveness of the aptamer. the cytotoxicity of aptamer-conjugated AgNPs against A549 (human non-small cell lung cancer) and BEAS-2B (normal human bronchial epithelial ) were studied using CTB test, cellular uptake, viability staining (using Calcein AM and Propidium Iodide), Quantitation of Apoptosis and Necrosis cells (using Annexin V and Propidium Iodide) and Cellular morphological changes (laser scanning confocal microscope and normal microscope). All results indicated that the effect of aptamer conjugated AgNPs was very large on cancer cells (A549 cells) compared to healthy cells (BEAS2B) at the same or lesser concentrations. This indicates that these nanoparticles exhibited selective binding and internalization to target A549 cells, but not by normal human bronchial epithelium BEAS2B, thus exhibiting high selective specificity

Using Low-cost IoT-based inclinometers for damage detection of a Bridge model

Nowadays, researchers are paying close attention to using inclinometers for Structural Health Monitoring (SHM) applications. Moreover, the applications based on using inclinometers can detect the magnitude and location of bridge pathologies. However, as these applications are based on expensive commercial inclinometers, their use is typically exclusive to the SHM of structures with a high monitoring budget. There is a gap in the literature with the development and validation of low-cost accurate angular-meters for decreasing the monitoring cost of inclinometer-based damage detection applications. This work aims to develop low-cost IoT-based inclinometers for detecting damage in bridge structures. The Low-cost Adaptable Reliable Angle-meter (LARA) is a novel inclinometer that accurately measures an induced inclination by combining the measurements of five gyroscopes and five accelerometers. The accuracy, resolution, Allan variance, and standard deviation of LARA are examined through laboratory experiments and are compared with those obtained by numerical slope calculations and a commercial inclinometer (HI-INC). For further experimental validation, a robotic vehicle model is designed and developed to simulate a moving load over a bridge model. The vehicle model integrates IoT technology and can be utilized in different damage detection experiments. The outcomes of a load test experiment using a simple beam model demonstrate the high accuracy (0.003 degrees) of LARA measurements. LARA may be used for structural damage identification and location in bridges utilizing inclinometers because of its low cost and high accuracy