抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Infectious Diseases Society of America.

Memristive devices are electrical resistance switches that can retain a state of internal resistance based on the history of applied voltage and current. These devices can store and process information, and offer several key performance characteristics that exceed conventional integrated circuit technology. An important class of memristive devices are two-terminal resistance switches based on ionic motion, which are built from a simple conductor/insulator/conductor thin-film stack. These devices were originally conceived in the late 1960s and recent progress has led to fast, low-energy, high-endurance devices that can be scaled down to less than 10 nm and stacked in three dimensions. However, the underlying device mechanisms remain unclear, which is a significant barrier to their widespread application. Here, we review recent progress in the development and understanding of memristive devices. We also examine the performance requirements for computing with memristive devices and detail how the outstanding challenges could be met.

Memristive devices for computing

Transparent electronics is today one of the most advanced topics for a wide range of device applications. The key components are wide bandgap semiconductors, where oxides of different origins play an important role, not only as passive component but also as active component, similar to what is observed in conventional semiconductors like silicon. Transparent electronics has gained special attention during the last few years and is today established as one of the most promising technologies for leading the next generation of flat panel display due to its excellent electronic performance. In this paper the recent progress in n- and p-type oxide based thin-film transistors (TFT) is reviewed, with special emphasis on solution-processed and p-type, and the major milestones already achieved with this emerging and very promising technology are summarizeed. After a short introduction where the main advantages of these semiconductors are presented, as well as the industry expectations, the beautiful history of TFTs is revisited, including the main landmarks in the last 80 years, finishing by referring to some papers that have played an important role in shaping transparent electronics. Then, an overview is presented of state of the art n-type TFTs processed by physical vapour deposition methods, and finally one of the most exciting, promising, and low cost but powerful technologies is discussed: solution-processed oxide TFTs. Moreover, a more detailed focus analysis will be given concerning p-type oxide TFTs, mainly centred on two of the most promising semiconductor candidates: copper oxide and tin oxide. The most recent data related to the production of complementary metal oxide semiconductor (CMOS) devices based on n- and p-type oxide TFT is also be presented. The last topic of this review is devoted to some emerging applications, finalizing with the main conclusions. Related work that originated at CENIMAT|I3N during the last six years is included in more detail, which has led to the fabrication of high performance n- and p-type oxide transistors as well as the fabrication of CMOS devices with and on paper.

Oxide Semiconductor Thin‐Film Transistors: A Review of Recent Advances

Despite much progress in semiconductor integrated circuit technology, the extreme complexity of the human cerebral cortex, with its approximately 10(14) synapses, makes the hardware implementation of neuromorphic networks with a comparable number of devices exceptionally challenging. To provide comparable complexity while operating much faster and with manageable power dissipation, networks based on circuits combining complementary metal-oxide-semiconductors (CMOSs) and adjustable two-terminal resistive devices (memristors) have been developed. In such circuits, the usual CMOS stack is augmented with one or several crossbar layers, with memristors at each crosspoint. There have recently been notable improvements in the fabrication of such memristive crossbars and their integration with CMOS circuits, including first demonstrations of their vertical integration. Separately, discrete memristors have been used as artificial synapses in neuromorphic networks. Very recently, such experiments have been extended to crossbar arrays of phase-change memristive devices. The adjustment of such devices, however, requires an additional transistor at each crosspoint, and hence these devices are much harder to scale than metal-oxide memristors, whose nonlinear current-voltage curves enable transistor-free operation. Here we report the experimental implementation of transistor-free metal-oxide memristor crossbars, with device variability sufficiently low to allow operation of integrated neural networks, in a simple network: a single-layer perceptron (an algorithm for linear classification). The network can be taught in situ using a coarse-grain variety of the delta rule algorithm to perform the perfect classification of 3 × 3-pixel black/white images into three classes (representing letters). This demonstration is an important step towards much larger and more complex memristive neuromorphic networks.

Training and operation of an integrated neuromorphic network based on metal-oxide memristors

In this paper, we propose a floating-gate-based synaptic transistor with two independent control gates that implement both offline and online learning. Unlike previous research on double-gated synaptic transistors, the proposed device is capable of online learning without facing a fan-out problem. Basic operation of the device was verified and a program/erase scheme based on Fowler-Northeim tunneling is suggested for the multi-conductance utilization of the synaptic device. With the proposed P/E scheme, an offline-trained single-layered hardware-based spiking neural network was simulated for MNIST classification, resulting in 87.37% classification accuracy with 10% conductance variation. To alleviate this performance degradation, the online learning method is applied on the offline-trained SNN by reusing 3,000 training images. The effectiveness of the proposed method is also verified under existence of the synaptic weight variance. As a result, up to 86.89% of the performance degradation is alleviated.

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Double-Gated Asymmetric Floating-Gate-Based Synaptic Device for Effective Performance Enhancement Through Online Learning

An analytic expression was obtained to examine the dependence of dielectric layers thickness and silicon radius on V th shift, which is an important characteristic of gate all around SONOS/TANOS memory. As the radius of silicon decreases, the V th shift decreases because of increasing capacitance in dielectric layers under the condition of same trapped charge density. The V th shift is almost linearly dependant on bottom oxide thickness and top oxide thickness. The maximum V th shift of TANOS is lower than that of SONOS because of high dielectric constant of blocking layer in TANOS. On the other hand, the program speed of TANOS is faster than that of SONOS.

A comparative study of the program efficiency of gate all around SONOS and TANOS flash memory

Trend and issues of the bulk FinFET

By utilizing the fringing electric field from the control gate of cells in NAND flash memory string, the source/drain in the cells could be removed, which improves cell scalability and gives very positive effects. In this scheme, cells with underlapped S/D or localized buried oxide in the space shown more reasonable read current characteristics. For NOR flash memory, cells with recess channel structure have studied. We demonstrated successful operation of 4-bit/cell using the recess structure and found no interference in a cell and adjacent cells. Finally, we compared measured RTN in FinFET SONOS and saddle SONOS devices. The current fluctuation of the FinFET devices is higher by ~3 times than that in the saddle devices. We expect that our approach is very promising for future high density and high performance flash memory technology.

Cell devices for high-density flash memory

Ameloblastoma is the most common benign odontogenic tumor of the jaw, and expansional growth of a huge untreated ameloblastoma can result in disturbances in facial aesthetics and function, such as difficulty with mouth opening, swallowing, chewing, breathing, neurologic deficits, and pathologic fractures Radical wide resection with safety margins and subsequent reconstruction is generally recommended A fibular free flap (FFF) is commonly used to reconstruct the mandible in order to adequately restore both aesthetic appearance and function The aim of this brief clinical report is to present a case of huge ameloblastoma after wide resection with free safety margins, and describe the immediate one-step mandibular reconstruction using a vascularized composite FFF The sterolithographic(rapid prototype, RP) model, a wax pattern of the resected mandible, and a surgical fibular stent made from the wax pattern were constructed preoperatively We suggest a standardized surgical protocol for mandibular reconstruction with FFF Funding : Supported by the International Research & Development Program of the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (NRF-2015K1A3A9A01028230) Keywords : Mandibular reconstruction, fibular osteocutaneous free flap, huge ameloblastoma, stereolithographic model, standardized formula

/pdf/a-standardized-formula-for-aesthetic-mandibular-50dclxbn44.pdf

Jong-Ho Lee

Papers

Double-Gated Asymmetric Floating-Gate-Based Synaptic Device for Effective Performance Enhancement Through Online Learning

A comparative study of the program efficiency of gate all around SONOS and TANOS flash memory

Trend and issues of the bulk FinFET

Cell devices for high-density flash memory

A standardized formula for aesthetic mandibular reconstruction using an osteocutaneous fibular free flap.