George M. Whitesides

Bio: George M. Whitesides is an academic researcher from Harvard University. The author has contributed to research in topics: Microcontact printing & Self-assembled monolayer. The author has an hindex of 240, co-authored 1739 publications receiving 269833 citations. Previous affiliations of George M. Whitesides include University of California, Davis & University of Texas at Austin.

Fabrication of small-scale cylindrical articles

Abstract: Techniques for fabrication of small-scale metallic structures such as microinductors, microtransformers and stents are described. A chemically active agent such as a catalyst is applied from an applicator in a pattern to an exterior surface of an article, metal is deposited according to the pattern and optionally, removed from the substrate. Where the substrate is cylindrical, the pattern can serve as a stent. Alternatively, a pattern of a self-assembled monolayer can be printed on a surface, which pattern can dictate metal plating or etching resulting in a patterned metal structure that can be cylindrical. In another embodiment, a structure is patterned on a surface that serves as a phase-modulating pattern or amplitude-modulating pattern. The article subsequently is exposed to radiation that can induce a change in refractive index within the article, and the phase-modulating or amplitude-modulating pattern results in different indices of refraction being created in different portions of the article. By this technique, a grating can be written into a core of an optical fiber.

Fabrication of Patterned, Electrically Conducting Polypyrrole Using a Self-Assembled Monolayer: A Route to All-Organic Circuits

Abstract: 526IntroductionPolypyrrole is potentially useful as an electricalconductor. It (and other organic conductors ) are difficultto process, particularly in features typical of circuits:they are generally insoluble and decompose upon melt-ing. Soluble or melt-processable derivatives of conju-gated polymers existl-a but often display reducedconductivities compared to their parent polynners. Thus,templating the shape of a conjugated polymer duringsynthesis (e.g., oxidative electropolymerization) mayprove useful. Templating environments such as giasscapillariesb and membrane pores6 have been used toform thin conducting wires of these polymers. Wesought to generalize this templating scheme to formarbitrary patterns on a surface.Recently, we have developed several techniques forthe patterning of a SA-N{ on a gold surface.; 1: of whichthe most generally useful tespecialll for complex pat-terns) is contact printing on microscaies. A number ofgroups have established that SAMs of an appropriatethickness (".9., > 10 carbons in length) essentially blockinterfacial electron transfer.l3 17 Conjugated polymerssuch as polypyrrole. polythiophene and poiyaniline are

Soft lithography and microfabrication

Abstract: Miniaturization is a central theme in technology. As the computer industry knows, smaller microelectronic devices have made computers faster, cheaper and more portable. These advances in microelectronics have also spawned a huge variety of other tiny devices. For example, micro-electro-mechanical systems are now being used in medicine as disposable blood-pressure sensors, and in the automotive industry as tiny accelerometers in airbags that protect drivers in crashes.

Screening derivatized peptide libraries for tight binding inhibitors to carbonic anhydrase II by electrospray ionization-mass spectrometry.

Abstract: This paper describes the use of electrospray ionization-mass spectrometry (ESI-MS) to screen two libraries of soluble compounds to search for tight binding inhibitors for carbonic anhydrase II (EC 4.2.1.1). The two libraries, H2NO2SC6H4C(O)NH-AA1-AA2-C(O)NHCH2CH2CO2H (1), where AA1 and AA2 are l-amino acids (library size: 289 compounds) or d-amino acids (256 compounds), were constructed by attaching tripeptides to the carboxyl group of 4-carboxybenzenesulfonamide. Screening of both libraries yielded, as the tightest binding inhibitor, compound 1 (AA1 = AA2 = l-Leu; binding constant Kb = 1.4 × 108 M-1). The ability of ESI-MS to estimate simultaneously the relative binding affinities of a protein to soluble ligands in a library, if general, should be useful in drug development.

I and i

Abstract: 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 …

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

Abstract: 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。

The Theory of Island Biogeography

Abstract: 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

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

Abstract: 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.

Fuzzy Nanoassemblies: Toward Layered Polymeric Multicomposites

Abstract: 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.