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

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

Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

The Theory of Island Biogeography

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

Multilayer films of organic compounds on solid surfaces have been studied for more than 60 years because they allow fabrication of multicomposite molecular assemblies of tailored architecture. However, both the Langmuir-Blodgett technique and chemisorption from solution can be used only with certain classes of molecules. An alternative approach—fabrication of multilayers by consecutive adsorption of polyanions and polycations—is far more general and has been extended to other materials such as proteins or colloids. Because polymers are typically flexible molecules, the resulting superlattice architectures are somewhat fuzzy structures, but the absence of crystallinity in these films is expected to be beneficial for many potential applications.

https://science.sciencemag.org/content/sci/277/5330/1232.full.pdf

Fuzzy Nanoassemblies: Toward Layered Polymeric Multicomposites

This paper demonstrates the use of poly(dimethylsiloxane) (PDMS), polyurethane (PU), epoxy, and poly(methyl methacrylate) (PMMA) as mandrils to fabricate metallic heat exchangers having 300-700 /spl mu/m internal channels. The mandrils were prepared using two soft lithographic techniques-replica molding and microembossing. To fabricate the heat exchangers, the polymeric mandrils were coated with a thin layer of metal by thermal evaporation or sputtering; this layer acted as the cathode for electrodeposition of a shell of nickel or copper that was 100 /spl mu/m thick. The polymers were removed by burning them out at 400/spl deg/C in air, or by dissolving them with a tetrahydrofuran solution of tetrabutylammonium fluoride. Studies of heat dissipation showed that the nickel heat exchangers with features that range in size from 150-750 /spl mu/m have thermal resistances ranging from 0.07 to 0.12/spl deg//sup -2/C W/sup -1/ cm at flow rates of water of /spl sim/20 L h/sup -1/ and pressures of 8.6-83/spl times/10/sup 3/ N m/sup -2/.

Fabrication of metallic heat exchangers using sacrificial polymer mandrils

This paper describes three types of gold electrodes, each with at least one spatiai dimension as small as 1 prm, fabricated using combinations of micromachining and molecular self-assembly. (i) Large-area (>0.1 mm2) arrays of band-type electrodes were formed by machining micrometer-wide grooves of bare gold into gold frlm covered with a -23-A-thick, electrically insulating, self-assembled monolayer (SAM) of CHs(CHz)rsS. (ii) Micrometer-wide, centimeter-long, 100-nm-thick gold electrodes supported on glass were fabricated by patterning a gold film with monolayers of CHs(CHz)rsS and HO(CHz)zS, and selectively etching the regions of gold covered with HO(CHz)zS using an aqueous solution of CN saturated with Oz. (iii) T\vo microelectrodes, each with electrochemically active areas as small as 100 nm x l rrm and separated from each other by a distance of I !rm, were formed by machining a l-pzm-wide gap into a supported gold wire covered with an electrically insulating SAM of CHs(CHz)rsS; exposed gold on either side of the machined gap formed the electrochemically active surfaces of the microelectrode pair.

Combining Micromachining and Molecular Self-Assembly To Fabricate Microelectrodes

Probing the energetics of dissociation of carbonic anhydrase-ligand complexes in the gas phase.

Fatty acid esters have been synthesized in good yield by reaction between copper(I) ate complexes formed from methylcopper(I) and primary or secondary Grignard reagents and esters of primary iodoalkylcarboxylic acids. The synthetic method is i l lustrated with proced.ures for CHr:gH(CHz)rgCO2C2H5, CeHsCHzO(CH2)16COzCzHs, CH3(CH2)25CO2C2H5, CH3O2C(CH)I2CO2CHI, CzHsOzC(CHz)szCO2C2H5, and CHg(CH2)4CH(CHs)(CHz)roCOzCHs. The reaction sequence uses starting Grignard reagent with high efficiency, provides product mixtures that are conveniently worked up, and tolerates a variety of functional groups. It provides the most direct route presently available to a variety of representative classes of simple fatty acids.

George M. Whitesides

Papers

Fabrication of metallic heat exchangers using sacrificial polymer mandrils

Combining Micromachining and Molecular Self-Assembly To Fabricate Microelectrodes

Probing the energetics of dissociation of carbonic anhydrase-ligand complexes in the gas phase.

Synthesis of fatty acids using organocopper (I) ate complexes derived from Grignard reagents.

Location and mobility of functional groups at the surface of oxidized, low-density polyethylene film