Recent Advances in Calcium-Based Anticancer Nanomaterials Exploiting Calcium Overload to Trigger Cell Apoptosis

Calcium ion is vital for the regulation of many cellular functions and serves as a second messenger in the signal transduction pathways. Once the intracellular Ca²⁺ level exceeds the tolerance of cells (called Ca²⁺ overload), oxidative stress, mitochondrial damage, and cell/mitochondria apoptosis happen. Therefore, Ca²⁺ overload has started to be deeply exploited as a new strategy for cancer therapy due to its high efficiency and satisfactory safety. This review aims to highlight the recent development of Ca²⁺-based nanomaterials (such as Ca₃(PO₄)₂, CaCO₃, CaO₂, CaH₂, CaS, and others) able to trigger intracellular Ca²⁺ overload and apoptosis in cancer therapy. The intracellular mechanisms of varied Ca²⁺-based nanomaterials and the different types of strategies to enhance Ca²⁺ overload are discussed in detail. Moreover, the design of more efficient Ca²⁺ overload-mediated cancer therapies is prospected mainly based on 1) the enhanced cellular uptake by surface modification and morphology optimization of nanomaterials, 2) the accelerated Ca²⁺ release from nanomaterials by increasing the intracellular H⁺ level and by photothermal effect, and 3) the overload maintenance by Ca²⁺ efflux inhibition, Ca²⁺ influx promotion, or promoting Ca²⁺ release from the endoplasmic reticulum.     

Artifact removal in magnetoencephalogram background activity with independent component analysis

The aim of this study was to assess whether independent component analysis (ICA) could be valuable to remove power line noise, cardiac, and ocular artifacts from magnetoencephalogram (MEG) background activity. The MEGs were recorded from 11 subjects with a 148-channel whole-head magnetometer. We used a statistical criterion to estimate the number of independent components. Then, a robust ICA algorithm decomposed the MEG epochs and several methods were applied to detect those artifacts. The whole process had been previously tested on synthetic data. We found that the line noise components could be easily detected by their frequency spectrum. In addition, the ocular artifacts could be identified by their frequency characteristics and scalp topography. Moreover, the cardiac artifact was better recognized by its skewness value than by its kurtosis one. Finally, the MEG signals were compared before and after artifact rejection to evaluate our method.     

An On-Chip Spectrum Analyzer for Analog Built-In Testing

This paper presents an analog built-in testing (BIT) architecture and its implementation. It enables the frequency response and harmonic distortion characterizations of an integrated device-under-test (DUT) through a digital off-chip interface. External analog instrumentation is avoided, reducing test time and cost. The proposed on-chip testing scheme uses a digital frequency synthesizer and a simple signal generator synchronized with a switched capacitor bandpass filter. A general methodology for the use of this structure in the functional verification of a DUT is also provided. The circuit-level design and experimental results of an integrated prototype in standard CMOS 0.5 m technology are presented to demonstrate the feasibility of the proposed BIT technique.Marcia G. Mendez-Rivera was born in Irapuato, Mexico in 1972. She received the Communications and Electronics Engineering Degree from the Universidad de Guanajuato, Guanajuato, Mexico. in 1996, the M.Sc. degree from the Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), Puebla, Mexico in 1998 and the M.Sc. from Texas A&M University, College Station in 2002. Her research interest is in the design and fabrication of analog and mixed-signal circuits.Alberto Valdes-Garcia born in 1978, grew up in San Mateo Atenco, Mexico. He received the B.S. in Electronic Systems Engineering degree from the Monterrey Institute of Technology (ITESM), Campus Toluca, Mexico in 1999 (with honors as the best score from all majors). Since the fall of 2000 he has been working towards the Ph.D. degree at Analog and Mixed-Signal Center (AMSC), Texas A&M University. During the spring and summer of 2000 he was a Design Engineer with Motorola Broadband Communications Sector. In the summer of 2002 he was with the Read Channel Design Group at Agere Systems where he investigated wide tuning range GHz LC VCOs for mass storage applications. During the summer of 2004 he was with the Mixed-Signal Communications IC Design Group at the IBM T. J. Watson Research Center, where worked on design and analysis of SiGe power amplifiers for millimeter wave radios. Since the fall of 2001 he has been a Semiconductor Research Corporation (SRC) research assistant at the AMSC working on the development of analog built-in testing techniques. Since the fall of 2000, Alberto has been the recipient of a scholarship from the Mexican National Council for Science and Technology (CONACYT). He represented Mexico in the 1994 Odyssey of the Mind World Creativity Contest and in the 1997 International Exposition for Young Scientists. His present research interests include built-in testing implementations for analog and RF circuits, system level design for wireless receivers and RF circuit design for UltraWideBand (UWB) communications.Jose Silva-Martinez was born in Tecamachalco, Puebla, México. He received the B.S. degree in electronics from the Universidad Autónoma de Puebla, México, in 1979, the M.Sc. degree from the Instituto Nacional de Astrofísica Optica y Electrónica (INAOE), Puebla, México, in 1981, and the Ph.D. degree from the Katholieke Univesiteit Leuven, Leuven Belgium in 1992. From 1981 to 1983, he was with the Electrical Engineering Department, INAOE, where he was involved with switched-capacitor circuit design. In 1983, he joined the Department of Electrical Engineering, Universidad Autonoma de Puebla, where he remained until 1993; He was a co-founder of the graduate program on Opto-Electronics in 1992. From 1985 to 1986, he was a Visiting Scholar in the Electrical Engineering Department, Texas A&M University. In 1993, he re-joined the Electronics Department, INAOE, and from May 1995 to December 1998, was the Head of the Electronics Department; He was a co-founder of the Ph.D. program on Electronics in 1993. He is currently with the Department of Electrical Engineering (Analog and Mixed Signal Center) Texas A&M University, at College Station, where He holds the position of Associate Professor. His current field of research is in the design and fabrication of integrated circuits for communication and biomedical application. Dr. Silva-Martinez has served as IEEE CASS Vice President Region-9 (1997–1998), and as Associate Editor for IEEE Transactions on Circuits and Systems part-II from 1997–1998 and May 2002–December 2003. Since January 2004 is serving as Associate Editor of IEEE TCAS Part-I. He was the main organizer of the 1998 and 1999 International IEEE-CAS Tour in region 9, and Chairman of the International Workshop on Mixed-Mode IC Design and Applications (1997–1999). He is the inaugural holder of the TI Professorship-I in Analog Engineering, Texas A&M University. He was a co-recipient of the 1990 European Solid-State Circuits Conference Best Paper Award.Edgar Sánchez-Sinencio was born in Mexico City, Mexico. He received the degree in communications and electronic engineering (Professional degree) from the National Polytechnic Institute of Mexico, Mexico City, the M.S.E.E. degree from Stanford University, CA, and the Ph.D. degree from the University of Illinois at Urbana-Champaign, in 1966, 1970, and 1973, respectively. In 1974 he held an industrial Post-Doctoral position with the Central Research Laboratories, Nippon Electric Company, Ltd., Kawasaki, Japan. From 1976 to 1983 he was the Head of the Department of Electronics at the Instituto Nacional de Astrofísica, Optica y Electrónica (INAOE), Puebla, Mexico. He was a Visiting Professor in the Department of Electrical Engineering at Texas A&M University, College Station, during the academic years of 1979–1980 and 1983-1984. He is currently the TI J Kilby Chair Professor and Director of the Analog and Mixed-Signal Center at Texas A&M University. He was the General Chairman of the 1983 26th Midwest Symposium on Circuits and Systems. He was an Associate Editor for IEEE Trans. on Circuits and Systems, (1985–1987), and an Associate Editor for the IEEE Trans. on Neural Networks. He is the former Editor-in-Chief of the Transactions on Circuits and Systems II. He is co-author of the book Switched Capacitor Circuits (Van Nostrand-Reinhold 1984), and co-editor of the book Low Voltage/Low-Power Integrated Circuits and Systems (IEEE Press 1999). In November 1995 he was awarded an Honoris Causa Doctorate by the National Institute for Astrophysics, Optics and Electronics, Mexico. The first honorary degree awarded for Microelectronic Circuit Design contributions. He is co-recipient of the 1995 Guillemin-Cauer for his work on Cellular Networks. He is a former IEEE CAS Vice President-Publications. He was also the co-recipient of the 1997 Darlington Award for his work on high-frequency filters He received the Circuits and Systems Society Golden Jubilee Medal in 1999. He was the IEEE Circuits and Systems Society, Representative to the Solid-State Circuits Society (2000–2002). He is presently a member of the IEEE Solid-State Circuits Fellow Award Committee. His present interests are in the area of RF-Communication circuits and analog and mixed-mode circuit design. He is an IEEE Fellow Member since 1992.     

Dynamic modeling of tunable analog integrated filters for a stability study of on-chip automatic tuning loops

Continuous-time filters with automatic tuning loops are nonlinear feedback systems that are potentially unstable. To ensure stability, particularly if the design of the loop controllers is to be improved, the appropriate linear dynamic modeling of the tunable filter, including control inputs, should be attained. This work aims to present a general dynamic modeling of continuous-time analog filters with automatic tuning capability. The general analysis leads to an equivalent small-signal linearized incremental model, from which transfer functions between output variables and control voltages are obtained. Subsequent to the analysis, it is possible to design compensated loops with enhanced stability and dynamic performance. By way of example, the modeling of a particular band-pass CMOS continuous-time analog filter is presented in this paper. Two transfer functions are derived: the transfer function between the output phase shift and the central frequency control voltage, and that between the output amplitude and the quality factor control voltage. These functions are required to properly tune the central frequency and quality factor parameters. This modeling makes it possible to propose an adaptive controller with improved stability and a possible implementation for such a controller. Finally, experimental results are shown for a CMOS 0.8 μm technology.     

License Plate Recognition for Parking Control System by Mathematical Morphology

Nowadays, license plate recognition for parking systems is a critical task to provide automatic control of customers and payment. This paper introduces a new method for automatic recognition of license plates of vehicles by mathematical morphology.The proposed method can provide the license plate number of the plates in different light conditions, colors,sizes, and inclination(angles). The algorithm can recognize the license plates of European Union vehicles quickly and correctly. The pattern learning of mathematical skeletons has high efficiency in the process. The performance of the algorithm is demonstrated well by the test in a parking control system.     

Thermal Aging Effects on Cu Ball Shear Strength and Cu/Al Intermetallic Growth

Intermetallic growth and ball shear behavior of annealed Cu wire bonds on Al have been studied. The shear strength of Cu ball bonds decreased with time, and ductile fracture was the dominant failure mode from 125°C to 150°C. Al pad peel-off occurred as the aging temperature was increased above 150°C. The overall Cu/Al intermetallic thickness exhibited parabolic behavior as a function of time. A linear correlation was established between ball shear strength, metal peel-off occurrence, and intermetallic growth. The Cu/Al intermetallic growth activation energy was 0.23 eV, and the intermetallics identified in the experiment were CuAl₂ and CuAl.     

A highly efficient receiver for satellite‐based automatic identification system signal detection

An innovative receiver architecture for the satellite‐based automatic identification system has been recently proposed. In this paper, we describe a few modifications that can be introduced on the algorithms for synchronization and detection, which provide an impressive performance improvement. The receiver architecture has been designed for an on‐board implementation, and a prototype has been implemented by the University of Parma and CGS S.p.A. Compagnia Generale per lo Spazio under the European Space Agency project FENICE (Flexible innovative AIS receiver prototype). A few modifications are also here described that could allow a further performance improvement in case of processing moved to ground‐based stations, based on a priori information there available. Copyright © 2014 John Wiley & Sons, Ltd.     

Antioxidant activity of virgin olive oil phenolic compounds in a micellar system†

The antioxidant activity of two virgin olive oils, obtained from the same olive (Olea europaea sativa) batch but processed with different hammer crushing conditions, was evaluated by measuring their protective action towards linoleic acid peroxidation in a micellar system. The antioxidant efficiency (AE) of the oil phenolic fraction was higher when the olives were processed with a higher hammer crusher rotation rate. HPLC analysis demonstrated that one of the main derivatives of oleuropein, indicated as 3,4-DHPEA-EDA (the dialdehydic form of elenolic acid linked with 3,4-dihydroxyphenylethanol), is present only in the oil with higher AE. 3,4-DHPEA-EDA showed the greatest antioxidant ability among virgin olive oil phenols. Its greater efficiency in the micellar system in comparison with 3,4-dihydroxyphenylethanol (3,4-DHPEA) is related to its greater lipophilicity. It is suggested that the behaviour in the water–micellar environment is representative of that in a real system such as tomato-based sauce with added virgin olive oil. © 1999 Society of Chemical Industry     

Highly Stretchable Conducting SIBS‐P3HT Fibers

Poly(styrene‐β‐isobutylene‐β‐styrene)‐poly(3‐hexylthiophene) (SIBS‐P3HT) conducting composite fibers are successfully produced using a continuous flow approach. Composite fibers are stiffer than SIBS fibers and able to withstand strains of up 975% before breaking. These composite fibers exhibit interesting reversible mechanical and electrical characteristics, which are applied to demonstrate their strain gauging capabilities. This will facilitate their potential applications in strain sensing or elastic electrodes. Here, the fabrication and characterization of highly stretchable electrically conducting SIBS‐P3HT fibers using a solvent/non‐solvent wet‐spinning technique is reported. This fabrication method combines the processability of conducting SIBS‐P3HT blends with wet‐spinning, resulting in fibers that could be easily spun up to several meters long. The resulting composite fiber materials exhibit an increased stiffness (higher Young’s modulus) but lower ductility compared to SIBS fibers. The fibers’ reversible mechanical and electrical characteristics are applied to demonstrate their strain gauging capabilities.     

Design of different planar geometries of antenna arrays for isoflux radiation in GEO satellites

The synthesis of different planar geometries of antenna arrays for isoflux radiation is presented in this paper. This synthesis considers the reduction of the side lobe level and the isoflux radiation requirements for Geostationary Earth Orbit satellites. The behavior of the radiation is studied in three geometries of two-dimensional antenna arrays such as uniform planar arrays, aperiodic planar arrays (APA) and concentric ring arrays (CRA). The well-known methods of genetic algorithm and particle swarm optimization are utilized for the optimization problem. In this way, the designs of APA and CRA presented in this paper could provide an acceptable solution for reducing the antenna hardware and simplifying the power feeding even more than results presented previously in the literature.