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.

Abstract The particle concentration in oil has a significant impact on the pressure signal of oil flow; it has multi-layer and multi-scale vibration characteristics. The pressure signal of oil was analyzed using the Morlet wavelet function on its for has 6-layer decomposition, and the corresponding wavelet coefficients of oil samples with different particle concentrations are obtained. The energy density and vibration energy distribution of pressure signals along time series are analyzed. The results show that with the increase of particle concentration in the oil, the number of the extreme value of the wavelet coefficient and its difference range is reduced in the range of 30–64 wavelet decomposition scale of the distributions of the real part of the wavelet coefficient of oil pulsating flow along with the time series, and the degree of cyclical of pressure signal gradually reduce; In the same particle concentration, the periodicity of pulsating flow decreases with the decrease of the wavelet decomposition scale; With the increase of particle concentration, the wavelet decomposition scales corresponding to the first and second main periods gradually increases, and the vibration frequency of the first and second main periods of the oil pulsating flow pressure signal decreases successively.

Extraction characteristics of pressure signals of oil pulsating flow with different particle concentration based on wavelet analysis

Percutaneous transhepatic biliary drainage (PTBD) does not always lead to a reduction in serum total bilirubin (TBil) level in patients with hepatocellular carcinoma and obstructive jaundice. We aimed to develop a model for pre-PTBD prediction of post-procedural TBil decrease in these patients. Retrospective database searches were conducted at four teaching hospitals (reference period: January 2010 to December 2018), and baseline characteristics of eligible patients were extracted. Any decrease in TBil after PTBD and the lowest level of TBil post-PTBD <5 mg/dL, 3 mg/dL, and 2 mg/dL were each taken as the standard of effectiveness for computation of its own predictive nomogram. For data dimension decrease and feature selection, the least absolute shrinkage and selection operator (LASSO) regression model was used. A multivariable logistic regression analysis was used to develop nomograms. Each nomogram's performance was internally evaluated for its calibration, discriminative ability, and clinical usefulness. Included in the study were 138 patients. The model for end-stage liver disease (MELD) score, platelet count, and portal vein thrombosis (PVT) were predictors in the nomogram for any decrease in TBil; international normalized ratio (INR), MELD score, platelet count, and PVT were predictors for a decrease to <5 mg/dL; MELD score, cholinesterase level (CHE), platelet count, and PVT were predictors for a decrease to <3 mg/dL; and MELD score, CHE, platelet count, and pre-albumin level were predictors for a decrease to <2 mg/dL. The clinical value of the nomograms was proven by decision curve analysis. These models may help inform clinical decision making for performing PTBD procedures. 

Prediction of effective percutaneous transhepatic biliary drainage in patients with hepatocellular carcinoma: A multi-central retrospective study

Androgen receptor transcriptionally inhibits programmed death ligand-1 (PD-L1) expression and influences immune escape in bladder cancer.

Methods to Measure the Inhibition of ABCG2 Transporter and Ferrochelatase Activity to Enhance Aminolevulinic Acid-Protoporphyrin IX Fluorescence-Guided Tumor Detection and Resection.

Rainfall-induced landslides commonly occur in residual-soil layers of Chenzhou city, China. Slope failure induced by rainfall is intimately related to changes in the mechanical property and microstructures of residual soils. In this study, series of direct shear tests were respectively conducted on four typical residual soils from the area of Chenzhou to study influences of rainwater on their mechanical behaviors. Meanwhile, X-ray diffraction (XRD) tests and scanning electron microscope (SEM) tests were also performed to investigate microstructure characteristic of several types of soils. Experimental results revealed that the shear strength of soils decreased with increasing water content and its development trends were obviously influenced by the types of residual soils. Meanwhile, the shear strength of soils increased with the increase of vertical loads, and the relationship between them could be well expressed by a linear function. As water content increased, the calculated cohesions and internal friction angles both decreased. XRD observations implied that several residual soils showed rich clay minerals, including pyrophyllite, illite, kaolinite and montmorillonite, etc. Microstructures of these soils presented a sheet-structure system which was composed of various-sized clay particles. During hydration, these clay minerals gradually transferred from a face-face arrangement to face-edge or even edge-edge one, leading to the softening of clay particles and the reduction of the contact force between soil particles.

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Mingwei Chen

Papers

Extraction characteristics of pressure signals of oil pulsating flow with different particle concentration based on wavelet analysis

Prediction of effective percutaneous transhepatic biliary drainage in patients with hepatocellular carcinoma: A multi-central retrospective study

Androgen receptor transcriptionally inhibits programmed death ligand-1 (PD-L1) expression and influences immune escape in bladder cancer.

Methods to Measure the Inhibition of ABCG2 Transporter and Ferrochelatase Activity to Enhance Aminolevulinic Acid-Protoporphyrin IX Fluorescence-Guided Tumor Detection and Resection.

Effects of Rainfall on Mechanical Behaviors of Residual-Soil Landslide