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In this article, a proposed 3-D cadmium telluride (CdTe) detector structure is presented and investigated. The electrical performance of the proposed structure is studied using 3-D TCAD simulations. The obtained results could be considered as a proof of concept for the feasibility of the performance of the presented detector under different operating conditions. For the proposed structure, the collection time is found to be about 1.3 ns at 15 V. The fast and hard response of the structure makes it suitable for high energy beams detection. The very low leakage current, which is about 16 pA at 16 V, allows the application of high bias voltages. Higher bias voltages (up to 16 V) may be required to decrease the proposed CdTe detector collection time without affecting its quality. Although the proposed detector structure is more appropriate to be biased at high voltages, these voltage values are still more less than those required in 2-D detectors. Based on this study, the proposed 3-D CdTe detector can be recommended for future high-energy physics and medical applications.

Faster than Nyquist has gained a lot of interest lately since it can enhance OFDM spectral efficiency, which most of current telecommunication systems are based on. This makes it the optimum candidate technology to be deployed for the upcoming systems that are basically based on legacy OFDM systems such as 5G. Towards an era where all devices are predicted to be online, the ease of implementation has become a must as expensive and large chips will not suit wearable devices and micro-computers. In this paper, we offer a system that is not only beneficial for next generation of telecommunication systems, but also adaptive in sense of self-optimization and also in a way that it can be backward compatible with conventional OFDM systems.

This work is to introduce an advanced calculation to enhance the energy efficiency of the radio base station for MU-MIMO-OFDM framework. Advanced Radio Resource Scheduling (ARRS) is introduced. Power utilization is considered a standout amongst the most imperative parts of the research for the wireless network. In view of the increasing mindfulness for saving the earth, and to give green frameworks. The calculations fundamentally divided into two phases. First, it discovers the resource shares, and the number of dynamic antennas in light of channel state based on essential Resource Allocations as Bandwidth Adaptation (BA) and Discontinuous Transmission (DTX). Secondly, it applies the Amplitude Carving Greedy (ACG) and Inverse Water Filling (IWF) Algorithms for the ARRS. Which finds the ideal number of resource blocks allocated to every client in view of the wanted rates, and the number of dynamic receiving antennas that maximize the utilization of base station power for the time changing frequency selective channel. The results illustrate that the proposed ARRS Algorithm is giving an upgrade in the diminishment of the supply power utilization from 10% in low rates up to 17% in high rates, compared with essential asset designation for RAPS calculations.

Injection-locked oscillators (ILOs) are one of many topologies used in forwarded-clock wireline applications. In this paper, a super-harmonic injection-locked ring oscillator (ILRO) is proposed. The proposed ILRO has been designed and simulated using a 130-nm CMOS technology. The circuit is injected with a 7.6-GHz clock signal and generates 10 output clocks of 1.52 GHz each. The proposed design occupies an area of approx. 0.001 , has a phase noise of -148.1 dBc/Hz at 1MHz offset frequency and consumes 9.97 mW from a 1.2-V supply achieving a figure of merit (FoM) of 201.8 dBc/Hz.

Single carrier-frequency division multiple access (SC-FDMA) multiple input multiple output systems should be properly designed in terms of their complexity, and bit error rate performance. This can be realized by frequency domain equalization. In this paper, the research work is dedicated to analyze and investigate the performance improvement of these systems via frequency domain equalization schemes. The bit error rate, a function of the signal to noise ratio, is the performance metric of interest which is utilized to evaluate the system under different standard hypothetical and realistic channel conditions. Using quadrature phase shift keying. The simulation results indicate that the performance of the SC-FDMA system using the Joint Complex Regularized Zero Forcing schemes is highly competitive to the minimum mean squared error s and conventional zero forcing schemes assuming different Carrier Frequency Offsets, and channel models.

The National Institute of Standards and Technology (NIST) started a process to select a symmetric-key encryption algorithm instead of DES. NIST determined the evaluation criteria that would be used to compare the candidate algorithms depending on the analyses and comments received, NIST selected five finalist algorithms (RC6, MARS, Rijndael, Serpent and Twofish). At the end, NIST selected Rijndael as the proposed Advanced Encryption Standard algorithm (AES). Although Twofish algorithm based on Feistel structure and possesses a large security margin, it has some drawbacks as The Twofish structure is not easy to analyses, the mixing of various operations makes it hard to give a clean analysis and forces us to use approximation techniques. Moreover, The use of key-dependent S-Boxes adds complexity and greatly increase the effort required to write automated tools to search for characteristics (differentials, linear, …) of the structure. In this paper a proposal of a new Secure Symmetric-key Encryption (SSE) algorithm based on Feistel structure is produced to overcome the previous drawbacks and produce a provable secure algorithm. Keywords-key cryptography; Block Ciphers; Substitution- Box; Diffusive Components; MDS; branch number.

PV) is one of the main resources of Renewable Energy, as it is environmental friendly and relatively cost effective. It is utilized to produce electricity from the abundant solar energy. A PV system consists of (PV) array of modules, DC/DC converter with a fixed load and maximum power point tracking MPPT controller. The DC/DC converter is controlled to operate at MPP of the PV array. In this paper a system with a controller based on Perturb and Observe (P&O) algorithm is implemented in MATLAB/SIMULINK. A new approach has been devised to reach the maximum power point in two steps. The first step is to get Vpvmax and Ipvmax of the array and then get the working value of the duty ratio to operate the DC/DC converter at Imax. The simulation results show the feasibility of the approach. This technique reduces the computational effort of the system.

Cognitive radio (CR) is a technology which can solve the scarcity and inefficiency of spectrum usage. It achieves this target by enabling the licensed and unlicensed users to share the same spectrum under the condition that the unlicensed user must minimize the power interference produced on the licensed user through using multiple antennas for the transmitters and receivers. This paper introduces the Interference management problem of a CR network for minimizing the interference power introduced to licensed receiver while satisfying capacity and power constraints for unlicensed user transmission. An algorithm is developed that converges to the optimal solution after a few several iterations. Performance of (4×4), (8×8) and (16×16) Multiple-Input Multiple-Output (MIMO) systems with different power constraint values are compared.

The Partial Shadowing (PS) is one of the hotspot topics and one of the significant challenges in the Photovoltaic (PV) systems. The PS of PV modules cause serious energy loss of the PV energy. It is observed (using detailed simulation MATLAB programs) that, The PS effect is clear on both of I-V & P-V output characteristics (Ch/s) curves. Also, it is observed that, the energy loss due to PS when no diode is used is significantly large. But when the diodes are used, the energy loss decreases appreciably. The saving in energy loss increases as the number of diodes per module increases. It is proposed here to increase the number of diodes per each group of solar cells results in saving of energy loss. This Paper shows the recommended number of bypass diodes (Internal or External) solution to reduce the energy loss. The internal solution by increasing of diodes number per module, while the external solution by increasing of diodes number per group. This paper also discusses the effect of increasing the operating voltage of the system on PS loss.

Previous work has shown that lipid nanoparticles (LNP) composed of an ionizable cationic lipid, a poly(ethylene glycol) (PEG) lipid, distearoylphosphatidylcholine (DSPC), cholesterol, and small interfering RNA (siRNA) can be efficiently manufactured employing microfluidic mixing techniques. Cryo-transmission electron microscopy (cryo-TEM) and molecular simulation studies indicate that these LNP systems exhibit a nanostructured core with periodic aqueous compartments containing siRNA. Here we examine first how the lipid composition influences the structural properties of LNP-siRNA systems produced by microfluidic mixing and, second, whether the microfluidic mixing technique can be extended to macromolecules larger than siRNA. It is shown that LNP-siRNA systems can exhibit progressively more bilayer structure as the proportion of bilayer DSPC lipid is increased, suggesting that the core of LNP-siRNA systems can exhibit a continuum of nanostructures depending on the proportions and structural preferences of component lipids. Second, it is shown that the microfluidic mixing technique can also be extended to encapsulation of much larger negatively charged polymers such mRNA (1.7 kb) or plasmid DNA (6 kb). Finally, as a demonstration of the generality of the microfluidic mixing encapsulation process, it is also demonstrated that negatively charged gold nanoparticles (5 nm diameter) can also be efficiently encapsulated in LNP containing cationic lipids. Interestingly, the nanostructure of these gold-containing LNP reveals a "currant bun" morphology as visualized by cryo-TEM. This structure is fully consistent with LNP-siRNA structure predicted by molecular modeling.

This paper introduces novel derived transformation equations to design dual-band filters. The design utilizes the approach adopted for dual-band bandpass filter design based on asymmetric half-wavelength resonator. The obtained optimized filter by this approach is used as a reference and the proposed transformation is applied to calculate the new filter design hardware parameters that satisfy its given specifications. Two dual-band filters are demonstrated by using this ransformation. The reference dual-band filter is designed to have: bandwidths of 96 MHz and 185 MHz at the central frequencies 2.1 GHz and 5.6 GHz for UMTS/ Wi-MAX applications, respectively. Another two dual-band filters for GPS/WiLAN and GPS/Wi-MAX applications are illustrated to verify the transformation technique. The momentum simulations for these filters show that the specifications are: bandwidths of 85 MHz and 100 MHz at the central frequencies 1.575 GHz and 5.8 GHz for the first one while bandwidths of 95 MHz and 100MHz at the central frequencies 1.5 GHz and 3.8 GHz for the second filter, respectively. All the results are obtained using circuit and momentum simulation of the Agilent Design Simulator (ADS) package.

Cognitive Radio applications in satellite communications become challenging and promising research owing to limitations over the available spectrum. Broadband satellite services continuously call for extra band resources, especially in Ka-band. The coexistence among multiple systems including two satellites systems and terrestrial networks sharing the band (17.7–18.1 GHz) is proposed. Harmful interference analysis and detection are provided based on Energy Detection and Matched Filter using an independent dipole chain at cognitive receiver. Also, spectrum sharing decision is deduced through simulation and analytical results. Then exploitation of 3D LCMV (Linearly Constrained Minimum Variance) is adapted for coexistence enabling between systems and protecting cognitive receivers. Spatial filtering is designed based on Focal Plane Array Reflector (FPAR). Finally, simulation and analytical results are used to provide a comparative performance evaluation of spectrum sensing techniques. Real link parameters and measurements from Nilesat (The Egyptian Satellite Company) are considered in calculations. In addition, 3D Beamforming performance evaluation is provided through simulation.

The global navigation satellite system (GPS) receiver has to lock on the satellites signals to calculate its position. The process of locking on the satellites is quite costly and requires millions of hardware multiplications, leading to high power consumption. In order to reduce the GPS receivers cost, acquisition time and power consumption; the complexity of the acquisition process should be reduced. In this paper, A modified algorithm is proposed to reduce the complexity of the time parallel acquisition algorithm with transition detection (TPATD) by using the Sparse Fourier Transform. The acquisition process is considered to two signals −24 dB (weak signal) and −30 dB (very weak signal) in presence of data bit-sign transitions. The complexity of the proposed algorithms without losing the sensitivity will be O (Np+ N/p log N/p) for very weak signals and O (N/p log N/p) for weak signals where p is the down sampling factor. The reduction in complexity because of the proposed algorithm is calculated for the mentioned cases. Simulation results show the performance of the proposed algorithm with the receiver operative characteristic curves using Monte Carlo simulations.

The in vivo gene silencing potencies of lipid nanoparticle (LNP)-siRNA systems containing the ionizable cationic lipids DLinDAP, DLinDMA, DLinKDMA, or DLinKC2-DMA can differ by three orders of magnitude. In this study, we examine the uptake and intracellular processing of LNP-siRNA systems containing these cationic lipids in a macrophage cell-line in an attempt to understand the reasons for different potencies. Although uptake of LNP is not dramatically influenced by cationic lipid composition, subsequent processing events can be strongly dependent on cationic lipid species. In particular, the low potency of LNP containing DLinDAP can be attributed to hydrolysis by endogenous lipases following uptake. LNP containing DLinKC2-DMA, DLinKDMA, or DLinDMA, which lack ester linkages, are not vulnerable to lipase digestion and facilitate much more potent gene silencing. The superior potency of DLinKC2-DMA compared with DLinKDMA or DLinDMA can be attributed to higher uptake and improved ability to stimulate siRNA release from endosomes subsequent to uptake.This study reports on the in vivo gene silencing potency of lipid nanoparticle-siRNA systems containing ionizable cationic lipids. It is concluded that the superior potency of DLinKC2-DMA compared with DLinKDMA or DLinDMA can be attributed to their higher uptake thus improved ability to stimulate siRNA release from endosome.

In this paper, a system of a hybrid pixel detector has been developed. The purpose is to create a flexible and reliable model that simulates the entire system, starting from a 3D detector to a data acquisition system and processing analysis. The model flexibility is achieved by minimizing interdependencies among its entities, so they can be added or removed as needed. The implementation of the system is accomplished using SILVACO and Simulink/MATLAB. The 3D detector is simulated using SILVACO to investigate its electrical performance. It is designed such that to have a good charge collection efficiency, position resolution and reduced charge sharing effects. Simulink is used to implement the readout circuit. The front-end readout circuit includes the Charge Sensitive Amplifier (CSA) and Active Shaper. The most suitable approach and parameters for a real system are selected according to the simulation results. Additionally, practical design constraints are also included in the model.

As OFDM has become the basis of many of telecommunication standards due to its ease of implementation, stability and efficiency, Faster-than-Nyquist signaling became an interesting base for envisioned telecommunication breakthrough, since it is based on an already used and successfully implemented technology which is OFDM, and it inherently obtains the legacy system merits, at the expense of system complexity. In this article we introduce signaling over none orthogonal carriers with a controllable orthogonality factor that optimizes channel usage based on channel quality feedback, with agility to cope with varying channels with rate higher that OFDM can tolerate.

Lipid nanoparticles (LNP) containing ionizable cationic lipids are the leading systems for enabling therapeutic applications of siRNA; however, the structure of these systems has not been defined. Here we examine the structure of LNP siRNA systems containing DLinKC2-DMA(an ionizable cationic lipid), phospholipid, cholesterol and a polyethylene glycol (PEG) lipid formed using a rapid microfluidic mixing process. Techniques employed include cryo-transmission electron microscopy, (31)P NMR, membrane fusion assays, density measurements, and molecular modeling. The experimental results indicate that these LNP siRNA systems have an interior lipid core containing siRNA duplexes complexed to cationic lipid and that the interior core also contains phospholipid and cholesterol. Consistent with experimental observations, molecular modeling calculations indicate that the interior of LNP siRNA systems exhibits a periodic structure of aqueous compartments, where some compartments contain siRNA. It is concluded that LNP siRNA systems formulated by rapid mixing of an ethanol solution of lipid with an aqueous medium containing siRNA exhibit a nanostructured core. The results give insight into the mechanism whereby LNP siRNA systems are formed, providing an understanding of the high encapsulation efficiencies that can be achieved and information on methods of constructing more sophisticated LNP systems.

Limit size systems are defined as the smallest achievable aggregates compatible with the packing of the molecular constituents in a defined and energetically stable structure. Here we report the use of rapid microfluidic mixing for the controlled synthesis of two types of limit size lipid nanoparticle (LNP) systems, having either polar or nonpolar cores. Specifically, limit size LNP consisting of 1-palmitoyl, 2- oleoyl phosphatidylcholine (POPC), cholesterol and the triglyceride triolein were synthesized by mixing a stream of ethanol containing dissolved lipid with an aqueous stream, employing a staggered herringbone micromixer. Millisecond mixing of aqueous and ethanol streams at high flow rate ratios (FRR) was used to rapidly increase the polarity of the medium, driving bottom-up synthesis of limit size LNP systems by spontaneous assembly. For POPC/triolein systems the limit size structures consisted of a hydrophobic core of triolein surrounded by a monolayer of POPC where the diameter could be rationally engineered over the range 20−80 nm by varying the POPC/triolein ratio. In the case of POPC and POPC/cholesterol (55/45; mol/mol) the limit size systems achieved were bilayer vesicles of approximately 20 and 40 nm diameter, respectively. We further show that doxorubicin, a representative weak base drug, can be efficiently loaded and retained in limit size POPC LNP, establishing potential utility as drug delivery systems. To our knowledge this is the first report of stable triglyceride emulsions in the 20−50 nm size range, and the first time vesicular systems in the 20−50 nm size range have been generated by a scalable manufacturing method. These results establish microfluidic mixing as a powerful and general approach to access novel LNP systems, with both polar or nonpolar core structures, in the sub-100 nm size range.

Lipid nanoparticles (LNPs) are currently the most effective in vivo delivery systems for silencing target genes in hepatocytes employing small interfering RNA. Antigen-presenting cells (APCs) are also potential targets for LNP siRNA. We examined the uptake, intracellular trafficking, and gene silencing potency in primary bone marrow macrophages (bmMΦ) and dendritic cells of siRNA formulated in LNPs containing four different ionizable cationic lipids namely DLinDAP, DLinDMA, DLinK-DMA, and DLinKC2-DMA. LNPs containing DLinKC2-DMA were the most potent formulations as determined by their ability to inhibit the production of GAPDH target protein. Also, LNPs containing DLinKC2-DMA were the most potent intracellular delivery agents as indicated by confocal studies of endosomal versus cytoplamic siRNA location using fluorescently labeled siRNA. DLinK-DMA and DLinKC2-DMA formulations exhibited improved gene silencing potencies relative to DLinDMA but were less toxic. In vivo results showed that LNP siRNA systems containing DLinKC2-DMA are effective agents for silencing GAPDH in APCs in the spleen and peritoneal cavity following systemic administration. Gene silencing in APCs was RNAi mediated and the use of larger LNPs resulted in substantially reduced hepatocyte silencing, while similar efficacy was maintained in APCs. These results are discussed with regard to the potential of LNP siRNA formulations to treat immunologically mediated diseases.

We adopted a rational approach to design cationic lipids for use in formulations to deliver small interfering RNA (siRNA). Starting with the ionizable cationic lipid 1,2-dilinoleyloxy-3-dimethylaminopropane (DLinDMA), a key lipid component of stable nucleic acid lipid particles (SNALP) as a benchmark, we used the proposed in vivo mechanism of action of ionizable cationic lipids to guide the design of DLinDMA-based lipids with superior delivery capacity. The best-performing lipid recovered after screening (DLin-KC2-DMA) was formulated and characterized in SNALP and demonstrated to have in vivo activity at siRNA doses as low as 0.01 mg/kg in rodents and 0.1 mg/kg in nonhuman primates. To our knowledge, this represents a substantial improvement over previous reports of in vivo endogenous hepatic gene silencing.

This paper describes the development of new configurations for flip-flops which are based on a microthyristor as a storage element, the NMOS transistor as a series switch or a driver and a high pull-up resistor. The performance of these flip-flops is analysed, using a PSPICE simulator. These devices perform well with regard to speed and power consumption and are more compact because of the use of the microthyrister.

This paper describes the construction of new circuit configurations for some sequential circuits. These circuits are based on the microthyristor as a microelectronic bistable device that can store logic one and logic zero and on NMOS transistors that act either as pass transistors or drivers. The shift register, considered as a main type of sequential circuit, is developed from a D flip-flop that is designed basically from the microthyristor as a bistable device. Moreover, different types of counters based on the microthyristor as a storing element are developed. Microthyristor sequential circuits were found to perform well.

Focal release of cytotoxic proteins by eosinophils onto the target surface plays an important role in parasite killing. Degranulation was stimulated by intracellular application of calcium and guanosine 5'-3-O-(thio)triphosphate via the recording patch pipette or via streptolysin-O permeabilization. Exocytotic fusion was monitored by capacitance measurements, whereas release of fluorescent weak bases, which accumulate selectively within eosinophil granules, was followed by fluorescence imaging. Several distinct types of granule fusion events were directly observed by simultaneous capacitance and fluorescence measurements. These are fusion of a single granule with the plasma membrane, intracellular granule-granule fusion, fusion of large compounds of pre-fused granules with the plasma membrane (compound exocytosis), and sequential fusion of granules to granules previously fused to the plasma membrane. Extensive granule-granule fusion was also observed by electron microscopy of permeabilized cells. All these fusion mechanisms contribute to focal release. The coexistence of distinct modes of exocytosis suggests that their regulation may modulate effector functions of eosinophils during helminth infection and allergic response.

In this paper, a new microthyristor structure suitable for microelectronics applications has been introduced. A suitable technology for its implementation has been chosen. The microthyristor has been designed and its performance has been simulated. The device showed superior performance concerning the switching times and the power dissipation in addition to controllability of its S-curve. During the development of this work, we introduced some new concepts such as doping-engineered devices, thyristor turn-off by shunting its cathode junction, and power consumption reduction by realizing high resistances. The basic requirements and some conditions are put together for successful launch of the microthyristor in microelectronics.

The mechanism whereby cationic lipids destabilize cell membranes to facilitate the intracellular delivery of macromolecules such as plasmid DNA or antisense oligonucleotides is not well understood. Here, we show that cationic lipids can destabilize lipid bilayers by promoting the formation of nonbilayer lipid structures. In particular, we show that mixtures of cationic lipids and anionic phospholipids preferentially adopt the inverted hexagonal (H(II)) phase. Further, the presence of 'helper' lipids such as dioleoylphosphatidylethanolamine or cholesterol, lipids that enhance cationic lipid-mediated transfection of cells also facilitate the formation of the H(II)phase. It is suggested that the ability of cationic lipids to promote nonbilayer structures in combination with anionic phospholipids leads to disruption of the endosomal membrane following uptake of nucleic acid-cationic lipid complexes into cells, thus facilitating cytoplasmic release of the plasmid or oligonucleotide.

Lipids, which adopt nonbilayer phases, have fascinated researchers as to the functional roles of these components in biomembranes. In particular, lipids capable of adopting the hexagonal H(II) phase have received considerable attention because of the observation that such lipids can promote membrane fusion. In the rational design of lipid-based delivery systems, H(II) phase lipids have been employed to endow systems with fusogenic, membrane-destabilizing properties. We will outline the molecular basis for the polymorphic phase behavior of lipids and highlight some of the uses of nonbilayer lipids in the preparation of lipid-based delivery systems. In addition, a distinction will be drawn between lipid-based systems which rely on the inclusion of nonbilayer lipids for activity, and systems which contain components which actively promote formation of nonbilayer structure within biological membranes.

SolubleN-ethylmaleimide-sensitive fusion protein attachment protein receptors (SNAREs) mediate vesicle fusion with the plasma membrane on activation by calcium binding to synaptotagmin. In the present study, we used fluorescence resonance energy transfer (FRET) and fluorescence lifetime imaging microscopy between fluorescently labeled SNARE proteins expressed in cultured rat hippocampal neurons to detect resting SNARE complexes, their conformational rearrangement on exocytosis, their disassembly before endocytosis of vesicular proteins, and SNARE assembly at newly docked vesicles. Assembled SNAREs are not only present in docked vesicles; unexpected residual “orphan SNARE complexes” also reside in para-active zone regions. Real-time changes in FRET between N-terminally labeled SNAP-25 and VAMP reported a reorientation of the SNARE motif upon exocytosis, SNARE disassembly in the active zone periphery, and SNARE reassembly in newly docked vesicles. With VAMP labeled C-terminally, decreased fluorescence in C-terminally labeled syntaxin (extracellular) reportedtrans-cis-conformational changes in SNAREs on vesicle fusion. After fusion SNAP-25 and syntaxin disperse along with VAMP, as well as the FRET signal itself, indicating diffusion of intact SNAREs after vesicle fusion but before their peripheral disassembly. Our measurements of spatiotemporal dynamics of SNARE conformational changes and movements refine models of SNARE function. Technical advances required to detect tiny changes in fluorescence in small fractions of labeled proteins in presynaptic boutons on a time scale of seconds permit the detection of rapid intermolecular interactions between small proportions of protein partners in cellular subcompartments.

The impact of Lightly Doped Drain structures (LDD) on the electrical characteristics of Si MOS transistors is investigated from liquid helium up to room temperature. It is found that the presence of LDD regions strongly alters the ohmic drain current characteristics at low temperatures ( ≤ 100 K). This feature is attributed to the increase of the source-drain series resistance due to the impurity freeze-out which takes place in the LDD regions. In contrast, it is also found that, for sufficiently high drain and gate voltages, the drain current is only weakly affected by the presence of LDDs. The analysis of the drain current and output conductance characteristics allows us to demonstrate that the LDD resistance is indeed a non-linear function of the longitudinal electric field. The above LDD resistance dependence with electric field is interpreted in term of field assisted impurity ionization which occurs in the LDD regions. The mechanisms responsible for the field assisted impurity ionization are discussed with regard to the Poole-Frenkel effect and the shallow level impact ionization process. Moreover, a simple model for the field dependent LDD resistance is proposed and makes it possible to explain quantitatively the change of the output conductance with temperature for MOS devices operated at low and very low temperatures.

In this short paper we introduce new complementary BiCMOS buffers employing multidrain/multi-collector structures. These circuits offer near rail-to-rail output voltage, less circuit complexity, less process complexity, and high performance at scaled down power supply voltages (

Special (lipid) delivery: The role of the ionizable lipid pK(a) in the in vivo delivery of siRNA by lipid nanoparticles has been studied with a large number of head group modifications to the lipids. A tight correlation between the lipid pK(a) value and silencing of the mouse FVII gene (FVII ED(50) ) was found, with an optimal pK(a) range of 6.2-6.5. The most potent cationic lipid from this study has ED(50) levels around 0.005 mg kg(-1) in mice and less than 0.03 mg kg(-1) in non-human primates.

DC characterization of n MOS inverters is carried out from liquid helium up to room temperatures. The benefits resulting from the low temperature operation on the performances of the n MOS inverter are studied. In particular, the improvement of the switching gain at low temperature is pointed out. Moreover, the relative noise margin is found to increase significantly at low temperature (≈50K). The possibility to operate the n MOS inverter at low temperature while reducing the supply voltage and in turn the power consumption is emphasized.

Formation of a fusion pore between a vesicle and its target membrane is thought to involve the so-called SNARE protein complex. However, there is no mechanistic model explaining how the fusion pore is opened by conformational changes in the SNARE complex. it has been suggested that C-terminal zipping triggers fusion pore opening. A SNAP-25 mutant named SNAP-25 Delta 9 (lacking the last nine C-terminal residues) should lead to a less-tight C-terminal zipping. Single exocytotic events in chromaffin cells expressing this mutant were characterized by carbon fiber amperometry and cell-attached patch capacitance measurements. Cells expressing SNAP-25 Delta 9 displayed smaller amperometric "foot-current" currents, reduced fusion pore conductances, and lower fusion pore expansion rates. We propose that SNARE/lipid complexes form proteolipid fusion pores. Fusion pores involving the SNAP-25 Delta 9 mutant will be less tightly zipped and may lead to a longer fusion pore structure, consistent with the observed decrease of fusion pore conductance.

A study of flicker noise in MOS transistors operated in the linear and non linear regions at room and liquid helium temperatures is proposed. Besides, a theoretical analysis of the drain current noise characteristics is developed in the framework of the mobility fluctuation model as well as of the carrier number fluctuation model. It is shown experimentally that a close correlation between the drain current spectral density and the transconductance squared dependencies with gate voltage (or drain current) and drain voltage is observed in our devices both at room and liquid helium temperatures. Therefore, it is concluded that the carrier number fluctuation model is not only applicable to MOS devices operated at room temperature but also at liquid helium temperature in ohmic and non ohmic regimes. In addition, peculiarities of the drain current noise related to the appearance of a kink effect at liquid helium temperature in the saturation current characteristics are also discussed.

An analysis of silicon metal‐oxide‐semiconductor (MOS) transistor operation at liquid‐helium temperature is presented. More specifically, analytical models providing the drain current and transconductance characteristics in the linear and nonohmic regions are established in the presence of source‐drain series resistances. These models, which rely on a specific mobility law for very low temperature, enable a good description of MOS transistor operation to be obtained. They permit the understanding and the prediction of the effects of source‐drain series resistance both in the linear and nonlinear regions. Furthermore, they allow a suitable parameter extraction method to be developed for the liquid‐helium temperature range. In addition, peculiarities of the drain voltage dependence of the mobility at low longitudinal electric field are also pointed out and empirically accounted for in the modeling of the output characteristics.

A numerical model for the ohmic operation of depletion-mode MOS transistors operated at very low temperature is presented. This model which is based on a quantum treatment of the accumulation layer and on a specific mobility law enables a good modelling of the transfer characteristics Id(Ug) and gm(Ug) to be obtained from weak to strong accumulation. An analytical version of this model is also derived for the strong accumulation region above flat-band. This model relies on simple analytical expressions which contain only three parameters i.e. the flat-band voltage Vfb, the maximum mobility μm and the mobility attenuation factor θlt. Moreover, a method for the extraction of the depletion-mode MOSFET parameters based on the plot of the I/g(Ug) characteristics is presented. Ein numerisches Modell fur den ohmschen Bereich von MOS-Verarmungstransistoren bei sehr tiefen Temperaturen wird angegeben. Dieses Modell, das auf einer Quantenberechnung der Akkumulationsschicht und einem spezifischen Beweglichkeitsgesetz beruht, erlaubt eine gute Modellierung der Transfercharakteristiken Id(Ug) und gm(Ug) im Bereich zwischen schwacher und starker Akkumulation. Eine analytische Version dieses Modells wird auch fur den starken Akkumulationsbereich oberhalb Flachband abgeleitet. Dieses Modell beruht auf einfachen analytischen Ausdrucken, die nur drei Parameter, die Flachbandspannung Ufb, die Maximalbeweglichkeit μm und den Beweglichkeitsdampfungsfaktor θlt enthalten. Daruberhinaus wird eine Methode zur Bestimmung der MOSFET-Verarmungsparameter angegeben, die auf der Auftragung von I/g (Ug)-Charakteristiken beruht.

The performance and the physical properties of SIMOX (separation by implantation of oxygen) MOS transistors are studied from room to liquid helium temperatures with particular emphasis on the behavior of carrier mobility, threshold voltage, subthreshold swing, leakage current, and kink effect. Various SIMOX substrates, such as partially depleted films annealed at low or high temperature and ultrathin films (100 nm), are analyzed and compared. Enhancement- and depletion-mode devices with different doping levels, channel lengths, and geometries are considered. The front and back channels are activated independently in order to assess the electrical quality of both interfaces. Comparison with bulk Si transistors reveals a number of interesting features of SIMOX devices, which are explained using comprehensive models. The advantages of low-temperature operation of SIMOX transistors are related to the decrease in subthreshold swing and leakage, increase in mobility, and reasonable shift of the threshold voltage. The performance of ultra-thin-film devices is excellent over the whole range or temperatures, whereas partially depleted transistors exhibit optimum performance at 77 K. >

An analysis of the kink effect in MOS transistors that provides a comprehensive view of the kink effect in bulk silicon MOSFETs and SOI devices is presented. This analysis enables a quantitative description of the excess drain current to be obtained for room and liquid-helium temperatures. In particular, it is found that the kink effect in a MOS transistor can be simply modeled by a body effect. >

Flicker noise in MOS transistors operated in the linear and non linear regions is studied at room and liquid helium temperatures. A theoretical analysis of the drain current noise is conducted within the mobility and carrier number fluctuation models. A close correlation between the drain current noise and the transconductance squared dependencies with gate and drain voltages is found experimentally both at room and liquid helium temperatures. It is concluded that the carrier number fluctuation model is suitable for the interpretation of our data at room and liquid helium temperatures in ohmic and non ohmic regimes. Peculiarities of the drain current noise in the kink effect region are also discussed.

Opening of individual exocytotic fusion pores in chromaffin cells was imaged electrochemically with high time resolution. Electrochemical detector arrays that consist of four platinum microelectrodes were microfabricated on a glass coverslip. Exocytosis of single vesicles containing catecholamines from a cell positioned on top of the array is detected by the individual electrodes as a time-resolved oxidation current, reflecting the time course of arrival of catecholamine molecules at the electrode surfaces. The signals exhibit low noise and reveal foot signals indicating fusion pore formation and expansion. The position of individual release events is determined from the fraction of catecholamines recorded by the individual electrodes. Simultaneous fluorescence imaging of release of acridine orange from individual vesicles confirmed the electrochemical position assignments. This electrochemical camera provides very high time resolution, spatiotemporal localization of individual fusion pore openings and quantitative data on the flux of transmitter from individual vesicles. Analysis of the amperometric currents employing random walk simulations indicates that the time course of amperometric spikes measured near the cell surface is due to a low apparent diffusion coefficient of cat-echolamines near the cell surface and not due to slow dissociation from the granular matrix.