Measurement of dissociation rate of biomolecular complexes using CE

Fluorescence anisotropy (FA), non-equilibrium CE of equilibrium mixtures (NECEEM) and high-speed CE were evaluated for measuring dissociation kinetics of peptide–protein binding systems. Fyn-SH3-SH2, a protein construct consisting of the src homology 2 (SH2) and 3 (SH3) domain of the protein Fyn, and a fluorescein-labeled phosphopeptide were used as a model system. All three methods gave comparable half-life of∼53 s for Fyn-SH3-SH2:peptide complex. Achieving satisfactory results by NECEEM required columns over 30 cm long. When using Fyn-SH2-SH3 tagged with glutathione S -transferase (GST) as the binding protein, both FA and NECEEM assays gave evidence of two complexes forming with the peptide, yet neither method allowed accurate measurement of dissociation rates for both complexes because of a lack of resolution. High-speed CE, with a 7 s separation time, enabled separation of both complexes and allowed determination of dissociation rate of both complexes independently. The two complexes had half-lives of 22.0±2.7 and 58.8±6.1 s, respectively. Concentration studies revealed that the GST-Fyn-SH3-SH2 protein formed a dimer so that complexes had binding ratios of 2:1 (protein-to-peptide ratio) and 2:2. Our results demonstrate that although all methods are suitable for 1:1 binding systems, high-speed CE is unique in allowing multiple complexes to be resolved simultaneously. This property allows determination of binding kinetics of complicated systems and makes the technique useful for discovering novel affinity interactions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/61861/1/457_ftp.pd

Autonomous and Environmentally Comfortable Type of Housing for the Development of the Arctic

Factors that impede the development of the Arctic are: 1) long frosts; 2) low quality of indoor air; 3) an unsanitary surroundings due to low activity of biota; 4) deficiency of fresh vitamin-containing food; 5) high dependency of settlements on external supply. The concept of the Arctic Ecological- Energy Autonomous Dwelling (AEEAD) designed to solve the problems is grounded on: 1) the optimal configuration of housing and heat savings; 2) closure of the flows of substances; 3) the use of autonomous energy sources. To ensure energy savings and maintain a high quality of life air revitalization is required. Air revitalization is provided by household greenhouses, which perform additional functions – heating the living quarters, lighting it, moistening the winter overdried air, growing food, decorating house interior, providing psychological support. New technologies for growing a variety of plants and organic wastes decomposition are discussed. Energetic autonomy is provided by means coupling wind generator with high-heat accumulators based on cheap solid heat-storage materials coupled, in its turn, with Stirling engine/electrical generator unit. Due to “macro-composite” structure of heat exchanger it can be achieved: almost zero heat loss in the absence of thermal insulation; a significant stabilization of the temperature at the output of the thermal battery, over the whole period of the discharg

Novel online data allocation for hybrid memories on tele-health systems

[EN] The developments of wearable devices such as Body Sensor Networks (BSNs) have greatly improved the capability of tele-health industry. Large amount of data will be collected from every local BSN in real-time. These data is processed by embedded systems including smart phones and tablets. After that, the data will be transferred to distributed storage systems for further processing. Traditional on-chip SRAMs cause critical power leakage issues and occupy relatively large chip areas. Therefore, hybrid memories, which combine volatile memories with non-volatile memories, are widely adopted in reducing the latency and energy cost on multi-core systems. However, most of the current works are about static data allocation for hybrid memories. Those mechanisms cannot achieve better data placement in real-time. Hence, we propose online data allocation for hybrid memories on embedded tele-health systems. In this paper, we present dynamic programming and heuristic approaches. Considering the difference between profiled data access and actual data access, the proposed algorithms use a feedback mechanism to improve the accuracy of data allocation during runtime. Experimental results demonstrate that, compared to greedy approaches, the proposed algorithms achieve 20%-40% performance improvement based on different benchmarks. (C) 2016 Elsevier B.V. All rights reserved.This work is supported by NSF CNS-1457506 and NSF CNS-1359557.Chen, L.; Qiu, M.; Dai, W.; Hassan Mohamed, H. (2017). Novel online data allocation for hybrid memories on tele-health systems. Microprocessors and Microsystems. 52:391-400. https://doi.org/10.1016/j.micpro.2016.08.003S3914005

Selection of aptamers for a protein target in cell lysate and their application to protein purification

Functional genomics requires structural and functional studies of a large number of proteins. While the production of proteins through over-expression in cultured cells is a relatively routine procedure, the subsequent protein purification from the cell lysate often represents a significant challenge. The most direct way of protein purification from a cell lysate is affinity purification using an affinity probe to the target protein. It is extremely difficult to develop antibodies, classical affinity probes, for a protein in the cell lysate; their development requires a pure protein. Thus, isolating the protein from the cell lysate requires antibodies, while developing antibodies requires a pure protein. Here we resolve this loop problem. We introduce AptaPIC, Aptamer-facilitated Protein Isolation from Cells, a technology that integrates (i) the development of aptamers for a protein in cell lysate and (ii) the utilization of the developed aptamers for protein isolation from the cell lysate. Using MutS protein as a target, we demonstrate that this technology is applicable to the target protein being at an expression level as low as 0.8% of the total protein in the lysate. AptaPIC has the potential to considerably speed up the purification of proteins and, thus, accelerate their structural and functional studies

Single-molecule techniques in biophysics : a review of the progress in methods and applications

Single-molecule biophysics has transformed our understanding of the fundamental molecular processes involved in living biological systems, but also of the fascinating physics of life. Far more exotic than a collection of exemplars of soft matter behaviour, active biological matter lives far from thermal equilibrium, and typically covers multiple length scales from the nanometre level of single molecules up several orders of magnitude to longer length scales in emergent structures of cells, tissues and organisms. Biological molecules are often characterized by an underlying instability, in that multiple metastable free energy states exist which are separated by energy levels of typically just a few multiples of the thermal energy scale of kBT, where kB is the Boltzmann constant and T the absolute temperature, implying complex, dynamic inter-conversion kinetics across this bumpy free energy landscape in the relatively hot, wet environment of real, living biological matter. The key utility of single-molecule biophysics lies in its ability to probe the underlying heterogeneity of free energy states across a population of molecules, which in general is too challenging for conventional ensemble level approaches which measure mean average properties. Parallel developments in both experimental and theoretical techniques have been key to the latest insights and are enabling the development of highly-multiplexed, correlative techniques to tackle previously intractable biological problems. Experimentally, technological developments in the sensitivity and speed of biomolecular detectors, the stability and efficiency of light sources, probes and microfluidics, have enabled and driven the study of heterogeneous behaviours both in vitro and in vivo that were previously undetectable by ensemble methods..

Graphene and Related Materials for Resistive Random Access Memories

Graphene and related materials (GRMs) are promising candidates for the fabrication of resistive random access memories (RRAM). Here, we analyze, classify and evaluate this emerging field, and summarize the performance of the RRAM prototypes using GRMs. Graphene oxide, amorphous carbon films, transition metal dichalcogenides, hexagonal boron nitride and black phosphorous can be used as resistive switching media, in which the switching can be governed either by the migration of intrinsic species or penetration of metallic ions from adjacent layers. Graphene can be used as electrode to provide flexibility and transparency, as well as an interface layer between the electrode and dielectric to block atomic diffusion, reduce power consumption, suppress surface effects, limit the number of conductive filaments in the dielectric, and improve device integration. GRMs-based RRAMs fit some non-volatile memory technological requirements like low operating voltages 10 years, endurance >109 cycles and power consumption ~10 pJ/transition still remain a challenge. More technology-oriented studies including reliability and variability analyses may lead to the development of GRMs-based RRAMs with realistic possibilities of commercialization.We acknowledge support from the Young 1000 Global Talent Recruitment Program of the Ministry of Education of China, the National Natural Science Foundation of China (grants no. 61502326, 41550110223), the Jiangsu Government (grant no. BK20150343), the Ministry of Finance of China (grant no. SX21400213), the Young 973 National Program of the Chinese Ministry of Science and Technology (grant no. 2015CB932700), the Collaborative Innovation Center of Suzhou Nano Science & Technology, the Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, the Priority Academic Program Development of Jiangsu Higher Education Institutions, the National Natural Science Foundation of China under Grant Nos. 61521064, 61322408, 61422407, the Beijing Training Project for the Leading Talents in S&T under Grant No. ljrc201508, the Opening Project of Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, the EU Graphene Flagship, FP7 Grant CARERAMM, ERC Grants Hetero2D and Highgraink, EPSRC Grants EP/K01711X/1, EP/K017144/1, EP/N010345/1, EP/M507799/1, EP/L016087/1, EP/M013243/1

Semiconductor device and DRAM

Data storage cells are formed on a substrate (13). Each of the data storage cells includes a field effect transistor with a source (18), drain (22) and gate (28) and a body arranged between the source and drain for storing electrical charge generated in the body. The magnitude of the net electrical charge in the body can be adjusted by input signals applied to the transistor and adjustment prevented by applying a voltage between the gate and drain and the source and the drain. An Independent claim is included for a method of storing data in a semiconductor devic

Method of forming an electric charge in a body of a semiconductor component

The device has a semiconductor layer provided on an insulating layer and including source and drain (18,20) regions to define a body (22) region of respective field effect transistors. An energy band modifying unit modifies the valence and conduction band of the body region to increase the amount of electrical charge that can be temporarily stored in the region. An Independent claim is also included for a method of controlling a semiconductor device

Semiconductor device

A semiconductor device, such as a memory device or radiation detector, is disclosed, in which data storage cells are formed on a substrate. Each of the data storage cells includes a field effect transistor having a source, drain, and gate, and a body arranged between the source and drain for storing electrical charge generated in the body. The magnitude of the net electrical charge in the body can be adjusted by input signals applied to the transistor, and the adjustment of the net electrical charge by the input signals can be at least partially cancelled by applying electrical voltage signals between the gate and the drain and between the source and the drain