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

Approaches, Derivatives and Applications Vasilios Georgakilas,† Michal Otyepka,‡ Athanasios B. Bourlinos,‡ Vimlesh Chandra, Namdong Kim, K. Christian Kemp, Pavel Hobza,‡,§,⊥ Radek Zboril,*,‡ and Kwang S. Kim* †Institute of Materials Science, NCSR “Demokritos”, Ag. Paraskevi Attikis, 15310 Athens, Greece ‡Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo naḿ. 2, 166 10 Prague 6, Czech Republic

Functionalization of Graphene: Covalent and Non-Covalent Approaches, Derivatives and Applications

Carbon dioxide is a major culprit of climate change, dramatically warming the Earth with its accumulation in the atmosphere. Converting CO2 to high end fuels could potentially solve environmental problems and create a sustainable energy cycle. In spite of Cu being the most successful catalyst capable of producing hydrocarbons from CO2, its efficiency suffers from high overpotentials, which originate from the highly endothermic CO protonation to CHO. Using density functional theory (DFT), we optimize the composition of a bimetallic core TMxNi13−x (TM = 3d transition metals; x = 3, 6, and 9) encapsulated in a 42 atom Cu icosahedral shell to lower the CO2 reduction overpotential. On Sc5(6)Ni8(7)–Cu42, this overpotential reduces to an unprecedented value of ∼0.17 V below the standard potential value (SPV). These specific core compositions optimize the position of the d-band center of the shell, required for better interaction with CHO π orbitals than CO, giving exergonic CO reduction. The estimated statistical coverage of CHO exceeds 60% under ambient conditions on Sc6Ni7–Cu42, which will promote CO2 conversion to the high end fuel CH4 without CO poisoning of the catalyst. The effect of implicit solvent is found to be marginal on the stability, reaction barriers and overpotentials, ensuring the robustness of Sc5(6)Ni8(7)–Cu42 for efficient CO2 electro-reduction.

Synergistic core–shell interactions enable ultra-low overpotentials for enhanced CO2 electro-reduction activity

We report the presence of giant spontaneous exchange bias (HSEB) in a hard and soft antiferromagnetic composite of BiFeO3-TbMnO3 (BFO-TMO in 7:3 and 8:2 ratio). The HSEB varies between 5-778Oe, but persists up to room temperature with a maximum near a spin reorientation transition temperature observed from magnetization vs. temperature measurement in Zero-field cooled (ZFC) and Field cooled (FC) modes. Isothermal remnant magnetization measurements at room temperature indicate the presence of an interfacial layer of a 2 dimensional dilute antiferromagnet in a field (2D DAFF). A stable value of the exchange bias has been observed via training effect measurements which signify the role of interfacial exchange coupling in the system. Based on the experimental results we explain the presence of the giant spontaneous exchange bias on the basis of a strong strain-mediated magnetoelectriccoupling induced exchange interaction and the creation of 2D DAFF layer at the interface. Theproperties of this layer are defined by canting and pinning of BFO spins at the interface with TMO due to Fe and Mn interaction. X-ray Magnetic Circular Dichroism (XMCD) confirms the presence of canted antiferromagnetic ordering of BiFeO3, charge transfer between Mn ions and different magnetically coupled layers which play vital role in getting the exchange bias.

Room temperature large spontaneous exchange bias in hard-soft antiferromagnetic composite BiFeO3-TbMnO3

A family of Mexican hat wavelet transforms associated with an isometry in the heat equation

Sebaceous gland carcinoma usually arises from the meibomian or Zeis glands within the eyelid, but tumor arising primarily from the conjunctiva, especially bulbar conjunctiva, is a rarity. We hereby report a case of a 50-year-old female who presented with a painless mass in the inferior limbus, encroaching the cornea and hanging over the lower eyelid without involving it. Imprint cytology was suggestive of adenosquamous carcinoma. Management consisted of wide local excision, cryotherapy to tumor bed, and topical 5-fluorouracil (5-FU) 1% preoperatively and postoperatively. Histopathologic analysis was in favor of sebaceous gland carcinoma. This case suggests that although sebaceous gland carcinoma commonly originates as a lid tumor, it can present as a bulbar conjunctival mass. Topical 5-FU is a viable and efficient cost-effective alternative for neo-adjuvant and adjuvant treatment of sebaceous gland carcinoma.

Primary sebaceous gland carcinoma of the bulbar conjunctiva without involvement of eyelid: A clinical dilemma.

The present article deals with the reflection and refraction phenomenon of a plane wave at the interface of two distinct functionally (exponentially) graded incompressible monoclinic media in the two separate cases. The first case (Case I) deliberates the influence of initial stress; however, the second case (Case II) analyses the influence of gravity associated with both upper and lower incompressible functionally graded monoclinic media on amplitude ratios of reflected and refracted waves. Two types of waves namely quasi-P and quasi-SV are generated due to the plane wave incident at the common interface of the considered structure. An analytical approach has been employed to compute velocity equations for each of the two cases. The dependency relations of dimensionless amplitude ratio of reflected and refracted waves on various affecting parameters along with angle of incidence have been established in closed form for both the cases. Moreover, the expressions for slowness section have also been derived for the corresponding cases and depicted by the means the graphs. Also as a special case of the problem, the deduced results are validated with the pre-established result. An analysis to unravel the effect of angle of incidence, gravity parameter, material gradient parameter and initial stress associated with lower and upper media on the reflected and refracted waves has also been made meticulously through numerical computations and graphical illustrations. Furthermore, through comparative analysis some important peculiarities in the phenomenon have also been highlighted.

Analysis of reflection and refraction of plane wave at the separating interface of two functionally graded incompressible monoclinic media under initial stress and gravity

Abhishek K. Singh

Papers

Synergistic core–shell interactions enable ultra-low overpotentials for enhanced CO2 electro-reduction activity

Room temperature large spontaneous exchange bias in hard-soft antiferromagnetic composite BiFeO3-TbMnO3

A family of Mexican hat wavelet transforms associated with an isometry in the heat equation

Primary sebaceous gland carcinoma of the bulbar conjunctiva without involvement of eyelid: A clinical dilemma.

Analysis of reflection and refraction of plane wave at the separating interface of two functionally graded incompressible monoclinic media under initial stress and gravity