다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

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

Two-dimensional materials are attractive for use in next-generation nanoelectronic devices because, compared to one-dimensional materials, it is relatively easy to fabricate complex structures from them. The most widely studied two-dimensional material is graphene, both because of its rich physics and its high mobility. However, pristine graphene does not have a bandgap, a property that is essential for many applications, including transistors. Engineering a graphene bandgap increases fabrication complexity and either reduces mobilities to the level of strained silicon films or requires high voltages. Although single layers of MoS(2) have a large intrinsic bandgap of 1.8 eV (ref. 16), previously reported mobilities in the 0.5-3 cm(2) V(-1) s(-1) range are too low for practical devices. Here, we use a halfnium oxide gate dielectric to demonstrate a room-temperature single-layer MoS(2) mobility of at least 200 cm(2) V(-1) s(-1), similar to that of graphene nanoribbons, and demonstrate transistors with room-temperature current on/off ratios of 1 × 10(8) and ultralow standby power dissipation. Because monolayer MoS(2) has a direct bandgap, it can be used to construct interband tunnel FETs, which offer lower power consumption than classical transistors. Monolayer MoS(2) could also complement graphene in applications that require thin transparent semiconductors, such as optoelectronics and energy harvesting.

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Single-layer MoS2 transistors

Problems associated with large-scale pattern growth of graphene constitute one of the main obstacles to using this material in device applications. Recently, macroscopic-scale graphene films were prepared by two-dimensional assembly of graphene sheets chemically derived from graphite crystals and graphene oxides. However, the sheet resistance of these films was found to be much larger than theoretically expected values. Here we report the direct synthesis of large-scale graphene films using chemical vapour deposition on thin nickel layers, and present two different methods of patterning the films and transferring them to arbitrary substrates. The transferred graphene films show very low sheet resistance of approximately 280 Omega per square, with approximately 80 per cent optical transparency. At low temperatures, the monolayers transferred to silicon dioxide substrates show electron mobility greater than 3,700 cm(2) V(-1) s(-1) and exhibit the half-integer quantum Hall effect, implying that the quality of graphene grown by chemical vapour deposition is as high as mechanically cleaved graphene. Employing the outstanding mechanical properties of graphene, we also demonstrate the macroscopic use of these highly conducting and transparent electrodes in flexible, stretchable, foldable electronics.

Large-scale pattern growth of graphene films for stretchable transparent electrodes

There is intense interest in graphene in fields such as physics, chemistry, and materials science, among others. Interest in graphene's exceptional physical properties, chemical tunability, and potential for applications has generated thousands of publications and an accelerating pace of research, making review of such research timely. Here is an overview of the synthesis, properties, and applications of graphene and related materials (primarily, graphite oxide and its colloidal suspensions and materials made from them), from a materials science perspective.

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Graphene and Graphene Oxide: Synthesis, Properties, and Applications

Ultrahigh electron mobility in suspended graphene

The resistivity of ultraclean suspended graphene is strongly temperature ($T$) dependent for $5lTl240\text{ }\text{ }\mathrm{K}$ At $T\ensuremath{\sim}5\text{ }\text{ }\mathrm{K}$ transport is near-ballistic in a device of $\ensuremath{\sim}2\text{ }\text{ }\ensuremath{\mu}\mathrm{m}$ dimension and a mobility $\ensuremath{\sim}170\text{ }000\text{ }\text{ }{\mathrm{cm}}^{2}/\mathrm{V}\text{ }\mathrm{s}$ At large carrier density, $ng05\ifmmode\times\else\texttimes\fi{}{10}^{11}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}2}$, the resistivity increases with increasing $T$ and is linear above 50 K, suggesting carrier scattering from acoustic phonons At $T=240\text{ }\text{ }\mathrm{K}$ the mobility is $\ensuremath{\sim}120\text{ }000\text{ }\text{ }{\mathrm{cm}}^{2}/\mathrm{V}\text{ }\mathrm{s}$, higher than in any known semiconductor At the charge neutral point we observe a nonuniversal conductivity that decreases with decreasing $T$, consistent with a density inhomogeneity $l{10}^{8}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}2}$

https://physics.aps.org/featured-article-pdf/10.1103/PhysRevLett.101.096802

Temperature-dependent transport in suspended graphene.

By muon spin-relaxation measurements on single-crystal specimens, we show that superconductivity in the $A{\text{Fe}}_{2}{\text{As}}_{2}$ $(A=\text{Ca},\text{Ba},\text{Sr})$ systems, in both the cases of composition and pressure tunings, coexists with a strong static magnetic order in a partial volume fraction. The superfluid response from the remaining paramagnetic volume fraction of $({\text{Ba}}_{0.5}{\text{K}}_{0.5}){\text{Fe}}_{2}{\text{As}}_{2}$ exhibits a nearly linear variation in $T$ at low temperatures, suggesting an anisotropic energy gap with line nodes and/or multigap effects.

/pdf/superconducting-state-coexisting-with-a-phase-separated-4iow3k1prh.pdf

K. J. Sikes

Papers

Ultrahigh electron mobility in suspended graphene

Temperature-dependent transport in suspended graphene.

Superconducting state coexisting with a phase-separated static magnetic order in (Ba,K)Fe2As2, (Sr,Na)Fe2As2, and CaFe2As2