There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

Fast parallel algorithms for short-range molecular dynamics

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

Single-layer metal dichalcogenides are two-dimensional semiconductors that present strong potential for electronic and sensing applications complementary to that of graphene.

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Electronics and optoelectronics of two-dimensional transition metal dichalcogenides.

Nanoengineered metal materials with the property of surface enhanced fluorescence (SEF) are attracting considerable attention due to their promising contribution to the fields such as biosensing and photonics by lowering the limit of detection (LOD) and enhancing the illumination efficiency. A variety of SEF materials such as nanoantennae [1, 2] and nanoparticles [3–8] have demonstrated significant fluorescence enhancement on organic fluorophores. Despite numerous advantages, such nanomaterials have their own limitations. Fabrication of SEF materials often involves complicated lithography processes, limiting their ubiquitous application. In addition, most SEF materials are designed to enhance fluorescence at certain local “hot spots” [4]; however, strong enhancement over a wide area is preferred in many applications. Herein we demonstrate a tunable three-dimensional (3D) free-standing nanoporous gold (NPG) film which greatly enhances the fluorescence of semiconductor quantum dots (QDs). QDs on the ligament experience near-field enhanced excitation and the decay of magnetic field, emitting more photons in a given time period. The NPG film is fabricated by simple chemical etching process and its nanopore size can be flexibly tuned by controlling the etching time and temperature. We demonstrate a high enhancement factor of ∼50-fold of QDs fluorescence achieved by NPG films. The superior fluorescence enhancement greatly improves imaging of single QDs using regular fluorescence microscopy.

Single quantum dot fluorescence enhancement by tunable nanoporous gold

This paper develops a risk model that captures the inherent uncertainties concerning the value and cost of a customized product. Analysis based on the model reveals that risks may handicap potential transactions and consequently prevent customers and manufactures from tapping into the value of customization. Prototyping, as commonly used in product customization, is then interpreted as a means of risk reduction and modeled via a Bayesian estimation process. Numerical analysis based on simulation is conducted to investigate the investment decision upon prototyping with respect to the fidelity and cost of the prototype. This paper provides a decision framework for practitioners to understand and manage transaction risks in product customization.

A simulation study of prototyping for risk reduction in product customization

Real-time monitoring of blood flow and thrombosis formation induced by laser irradiation is critical to reveal the thermal-damage mechanism and successfully implement vascular-dermatology laser surgery. Laser speckle contrast imaging (LSCI) is a non-invasive technique to visualize perfusion in various tissues. However, the ability of the LSCI to monitor the transient thermal response of blood vessels, especially thrombus formation during laser irradiation, requires further research. In this paper, an LSCI system was constructed and a 632 nm He-Ne laser was employed to illuminate a Sprague Dawley rat dorsal skin chamber model irradiated by a 1064 nm Nd: YAG therapy laser. The anisotropic diffusion filtering (ADF) technique is implemented after temporal LSCI (tLSCI) processing to improve the SNR and temporal resolution. The speckle flow index is used to characterize the blood-flow velocity to reduce the computational cost. The combination of the tLSCI and ADF increases the temporal resolution by five times and the SNR by 17.2 times and 16.14 times, without and with laser therapy, respectively. The laser-induced thrombus formation and vascular damage during laser surgery can be visualized without any exogenous labels, which provides a powerful tool for thrombus monitoring during laser surgery.

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Transient Thermal Response of Blood Vessels during Laser Irradiation Monitored by Laser Speckle Contrast Imaging

Locking screws with a typical buttress thread have high levels of failure in patients with osteoporotic bones. This study aims to develop a novel thread design for the locking screw and compare its fixation stability with the typical buttress thread.Locking screws with a novel thread design that possess an undercut feature and locking screws with a typical buttress thread were manufactured from stainless steel. Their fixation stabilities were then evaluated individually under a lateral migration test and evaluated in pairs together with a locking plate (LP) in an osteoporotic bone substitute under cyclic craniocaudal and torsional loadings. A finite element analysis (FEA) model was constructed to analyze the stress distributions present in the bone tissue adjacent to the novel thread versus the buttress thread.The biomechanical test revealed that the novel thread had a significantly higher lateral migration strength than the buttress thread. When applied to a LP, the locking screw with the novel thread requires more cycles and higher forces or torque to resist migration up to 5 mm or 10° than the buttress thread. The FEA simulation showed that the novel thread can make the stress distribute more evenly at the adjacent bone tissue when compared with the buttress thread.The locking screw with the novel undercut thread had superior lateral migration resistance during both initial and continued migration and superior fixation stability when applied to a LP under both cyclic craniocaudal loading and torsional loading than the locking screw with a typical buttress thread. 

Development and initial validation of a novel undercut thread design for locking screws.

/pdf/correction-to-electroacupuncture-ameliorates-cognitive-1jhv5r72.pdf

Correction to: Electroacupuncture Ameliorates Cognitive Impairment Through the Inhibition of NLRP3 Inflammasome Activation by Regulating Melatonin-Mediated Mitophagy in Stroke Rats

Mingwei Chen

Papers

Single quantum dot fluorescence enhancement by tunable nanoporous gold

A simulation study of prototyping for risk reduction in product customization

Transient Thermal Response of Blood Vessels during Laser Irradiation Monitored by Laser Speckle Contrast Imaging

Development and initial validation of a novel undercut thread design for locking screws.

Correction to: Electroacupuncture Ameliorates Cognitive Impairment Through the Inhibition of NLRP3 Inflammasome Activation by Regulating Melatonin-Mediated Mitophagy in Stroke Rats