Tạp chí khoa học số 2006-11-17

17 November 2006 | $10 High-Temperature Superconductivity Turns 20 >> page 1072 www.piercenet.com Tel: 815-968-0747 or 800-874-3723 • Fax: 815-968-7316 Customer Assistance E-mail: CS@piercenet.com © Pierce Biotechnology, Inc., 2006. Pierce products are supplied for laboratory or manufacturing applications only. Slide-A-Lyzer ® is a registered trademark of Pierce Biotechnology, Inc. Slide-A-Lyzer ® Dialysis Cassette Technology is protected by US patent # 5,503,741 and 7,056,440. *Void where prohibited. Limit one frame per order. For European offices and distributors, visit www.perbio.com For distributors outside the U.S. and Europe, visit www.piercenet.com How does the Cassette dialyze? 1. Inject sample into the Cassette through one of the guide ports on top of the gasket. Draw up on the syringe to remove air. 2. For Cassettes other than the 12-30 ml unit, attach a flotation buoy and dialyze. Forget about having to hassle with dialysis bag suspension! 3. After dialysis, inject the Cassette chamber with air, and withdraw your dialyzed sample from the Cassette. High-Performance Dialysis Dialysis The Protein People ™ No more leaking! Avoid sample loss with Pierce Slide-A-Lyzer ® Dialysis Cassettes. The Pierce Slide-A-Lyzer ® Dialysis Cassettes have a silicone-like gasket that prevents them from leaking. The new color-coded transparent frames allow you to instantly know the MWCO of the membrane and to see the sample being injected. No knots, caps, lids or clamps to loosen, fall off or leak. Obtain >95% sample recovery with a rigid frame that permits smooth and complete withdrawal of samples. Easy to hold on to frame and inject sample. >95% sample recovery. Sample remains intact with no contamination from surrounding dialysate. High surface area/sample volume ratio will dialyze twice as fast as conventional tubing. SAMPLE HANDLING SAMPLE RECOVER Y SAMPLE INTEGRITY SPEED 20 K MWCO Slide-A-Lyzer ® Cassettes are available in 2, 3.5, 7, 10 and now 20 K MWCO. See our website for the full line that best serves your dialysis needs. New! FREE picture frame offer!* Buy any package of Slide-A-Lyzer ® Dialysis Cassettes before 12/31/06 and receive a free magnetic picture frame that looks just like our Cassettes! SLIPPERY WHEN WET. Flat tubing is difficult to handle and fill when wet. SLIPPERY WHEN WET. Sample can easily be lost when tubing leaks or clamps slip off. SLIPPERY WHEN WET. Leaking into dialysate can compromise sample. SLIPPERY WHEN WET. Typically dialyze overnight. Difficult to recover sample from wet tubing. vs. A MPLIF I C A T I ON C E LL BIOLOGY C L ONI N G MIC R O A RRA Y S N U C L E I C A C I D A N A L Y S I S PROT EIN FUNCTION & ANALYS I S QU A NTI T A T I V E P C R S O F T W A R E S O L U T I ONS Our Mx3000P ® and Mx3005P ™ personal quantitative PCR (QPCR) Systems combine an advanced optical system with powerful data analysis to give you complete flexibility at an affordable price. Our open platform design supports traditional and advanced applications as well as newly emerging QPCR chemistries. In addition, our MxPro ™ QPCR Software combines leading edge data analysis algorithms with intuitive organization designed for ultimate ease-of-use. Need More Information? Give Us A Call: Stratagene US and Canada Order: 800-424-5444 x3 Technical Service: 800-894-1304 x2 Stratagene Europe Order: 00800-7000-7000 Te chnical Service: 00800-7400-7400 www.stratagene.com Stratagene Japan K.K. Order: 3-5821-8077 Technical Service: 3-5821-8076 Systems that set the standard, software that’s a step ahead. Lead the way with a Stratagene personal QPCR system featuring enhanced MxPro ™ QPCR Software. • Four- or five-color systems to best fit your research needs • 96-well thermal block with temperature uniformity of +/-0.25°C • New MxPro ™ QPCR Software with optional features for 21 CFR Part 11 compatibility Mx3000P ® is a registered trademarkof Stratagene in the United States. Mx3005P ™ and MxPro ™ are trademarks of Stratagene in the United States. GE Healthcare When it comes to life sciences, GE Healthcare is setting the standard. Tens of thousands of scientists worldwide rely on our products and proven expertise in protein analysis and detection every day. But we’re never content to stand still. We’re constantly striving for innovations that boost accuracy and deliver quantitative data. The result is new fluorescence platforms like the Ettan ™ DIGE Imager and Amersham ECL Plex ™ for quantitative protein analysis. By continually developing technology that can turn your scientific ideas into reality, we’re bringing science to life and helping to transform drug discovery and healthcare. We call it Protein Analysis Re-Imagined. Discover the full power of Ettan DIGE and the Amersham ECL ™ family of Western blotting systems at www.gehealthcare.com/protein_analysis Bringing protein analysis to life with Ettan DIGE and Amersham ECL GE Healthcare Bio-Sciences AB, a General Electric Company. Björkgatan 30, 751 84 Uppsala, Sweden. © 2006 General Electric Company - All rights reserved. GE08-06 www.sciencemag.org SCIENCE VOL 314 17 NOVEMBER 2006 1037 CONTENTS CONTENTS continued >> DEPARTMENTS 1043 Science Online 1045 This Week in Science 1050 Editors’ Choice 1054 Contact Science 1057 Random Samples 1059 Newsmakers 1161 New Products 1162 Science Careers For related online content, see page 1043 EDITORIAL 1049 Don’t Grandfather Coal Plants by M. Granger Morgan 1072 INTRODUCTION The Right Combination 1099 PERSPECTIVE Composites in Armor 1100 P. J. Hogg REVIEWS In Quest of Virtual Tests for Structural Composites 1102 B. Cox and Q. Yang Nanoparticle Polymer Composites: Where Two Small 1107 Worlds Meet A. C. Balazs, T. Emrick, T. P. Russell SPECIAL SECTION Materials Science: Composites Volume 314, Issue 5802 COVER Fluorescence optical microscopy image of cadmium selenide nanoparticles. These polyethylene glycol–functionalized nanoparticles have segregated to cracks in a composite film confined between a brittle silicon oxide layer and a silicon substrate. Field of view is 30 by 50 μm. See the special section on materials science beginning on page 1099. Image: S. Gupta and Q. Zhang NEWS OF THE WEEK Election 2006 Science Awaits Impact of Democratic Sweep 1060 in Congress Environmentalists See a Greener Congress 1061 Gordon Steps Up to House Science Post 1061 Stem Cell Supporters Hail Results, But Political 1062 Lessons Aren’t Clear Scientists Get Out the Word 1063 Elsewhere on the Election Front 1063 False Alarm: Atlantic Conveyor Belt Hasn’t 1064 Slowed Down After All Novartis Invests $100 Million in Shanghai 1064 Electronic Nuisance Changes Its Ways 1065 >> Report p. 1121 SCIENCESCOPE 1065 SARS and Bird Flu Veteran to Take WHO Helm 1067 NEWS FOCUS The Dawn of Stone Age Genomics 1068 >> Research Article p. 1113 A Neandertal Legacy? Special Report: High-Temperature Superconductivity Turns 20 High T c : The Mystery That Defies Solution 1072 >> Science Express Reports by T. Valla et al. and K. Tanaka et al. The Next Big Hurdle: Economics 1075 Determined Duo Scored a Victory for 1078 Small-Scale Science The BioRobot EZ1 is useddaily in hundreds offorensic and clinicallaboratories worldwide.It makes nucleic acid purification easy, ro bust, and reproducible for a wide range of applications. ■ Unparalleled inhibitor removal — from body fluids, swabs, or crime-scene samples ■ Reliable and flexible purification — using presealed reagent cartridges for DNA or RNA ■ Rapid results — purify 1 to 6 samples in as little as 15–20 minutes The BioRobot EZ1 workstation is intended forresearch applications. No claim orrepresentation is intended for itsuse to provide information for the diagnosis, prevention, or treatment of a disease. Trademarks:QIAGEN ® , BioRobot ® (QIAGENGroup). AUTOEZ110061WW © 2006 QIAGEN, all rights reserved. Integrated Solutions—Forensic and Clinical Labs Standard-setting nucleic acid purification WWW. Q I AGEN. C OM BioRobot EZ1 Visit www.qiagen.com/goto/EZ1mylab to find out more! www.sciencemag.org SCIENCE VOL 314 17 NOVEMBER 2006 1039 CONTENTS continued >> SCIENCE EXPRESS www.sciencexpress.org PHYSICS The Ground State of the Pseudogap in Cuprate Superconductors T. Valla, A. V. Fedorov, J. Lee, J. C. Davis, G. D. Gu The existence of an energy gap in a nonsuperconducting cuprate suggests that a comparable gap in superconductors arises as electrons pair up but are not fully coherent. >> News story p. 1072 10.1126/science.1134742 PHYSICS Distinct Fermi-Momentum–Dependent Energy Gaps in Deeply Underdoped Bi2212 K. Tanaka et al. Spectrometry on a high-temperature superconductor lacking a few of its electrons reveals that two additional energy gaps separate the pseudogap and the true superconducting gap. >> News story p. 1072 10.1126/science.1133411 PLANT SCIENCE A Cytokinin Perception Mutant Colonized by Rhizobium in the Absence of Nodule Organogenesis J. D. Murray, B. J. Karas, S. Sato, S. Tabata, L. Amyot, K. Szczyglowski 10.1126/science.1132514 A Gain-of-Function Mutation in a Cytokinin Receptor Triggers Spontaneous Root Nodule Organogenesis L. Tirichine et al. In the legume Lotus, symbiotic, nitrogen-fixing bacteria induce formation of the root nodules in which they reside by eliciting a growth response from the plant itself. 10.1126/science.1132397 CONTENTS LETTERS Why Aren’t There More Scientists Advocating 1081 for Funding? R. D. Wells and P. Farnham Fighting Waterborne Infectious Diseases R. C. Spear et al. Response A. Fenwick Debating the Worth of NCCAM Research S. Folkman et al. Response D. M. Marcus and A. P. Grollman BOOKS ET AL. The Regulatory Genome Gene Regulatory Networks 1085 in Development and Evolution E. H. Davidson, reviewed by D. Arendt The Reluctant Mr. Darwin An Intimate Portrait of 1086 Charles Darwin and the Making of His Theory of Evolution D. Quammen, reviewed by J. Browne POLICY FORUM NIH in the Post-Doubling Era: 1088 Realities and Strategies E. A. Zerhouni PERSPECTIVES Money Is Material 1091 C. B. Burgoyne and S. E. G. Lea >> Report p. 1154 Why Do Freezing Rocks Break? 1092 B. Hallet >> Report p. 1127 What Do Robots Dream Of? 1093 C. Adami >> Report p. 1118 Sara Splits the Signal 1094 J. A. Knoblich >> Report p. 1135 Breaking the H 2 Marriage and Reuniting the Couple 1096 G. J. Kubas >> Report p. 1124 RNA Polymerase, a Scrunching Machine 1097 J. W. Roberts >> Reports pp. 1139 and 1144 BREVIA ECOLOGY Rapid Temporal Reversal in Predator-Driven 1111 Natural Selection J. B. Losos, T. W. Schoener, R. B. Langerhans, D. A. Spiller As island lizards shift from ground to trees to escape predators, the selective pressure favors longer legs instead of the shorter legs favored on the ground. RESEARCH ARTICLE EVOLUTION Sequencing and Analysis of Neanderthal 1113 Genomic DNA J. P. Noonan et al. The sequences of DNA fragments from Neanderthal bones date the divergence of humans and Neanderthals to about 370,000 years ago. >> News story p. 1068 REPORTS COMPUTER SCIENCE Resilient Machines Through Continuous 1118 Self-Modeling J. Bongard, V. Zykov, H. Lipson When it receives appropriate sensory information, a mobile robot can compensate for damage to one of its four legs by updating an internal model of itself. >> Perspective p. 1093 PHYSICS Solid-State Thermal Rectifier 1121 C. W. Chang, D. Okawa, A. Majumdar, A. Zettl Systematically increasing the amount of a platinum compound along the length of a boron or carbon nanotube allows heat to flow preferentially in the opposite direction. >> News story p. 1065 miRNA Expression Profiling Analyze miRNA levels across samples • mir Vana™ miRNA Bioarrays • mir Vana™ miRNA Probe Set • mir Vana™ miRNA LabelingKit miRNA Isolation Collect small RNAs that other kits miss • mirVana™ RNA Isolation Kit (for miRNA) • RecoverAll™ Total Nucleic AcidIsolation Kit (for FFPE samples) miRNA Functional Analysis Uncover the regulatory roles of miRNAs • Pre-miR™ miRNA Precursors • Anti-miR™ miRNA Inhibitors • pMIR-REPORT™ miRNA ReporterVector Ambion, Inc. U.S. 800-327-3002 • Canada 800-668-6913 U.S. tel +1-512-651-0200 •f ax +1-512-651-0201 Direct free phone numbers, distributors: www.ambion.com/contact © Copyright 2006 Ambion , Inc. All rights reserved. Ambion (Europe)Ltd tel +44 (0)1480-373-020 fax + 44 (0)1480-373-010 Applied Biosystems Japan, Ltd. tel +03 (5566)6100 fax + 0 3 (5566)6501 An Applied Biosystems Business mirVana ™ miRNA Bioarrays V2 • Comprehensive, pre-printed probe panel for expression profiling of human, mouse, and rat microRNAs • Probes to all human, mouse and rat miRNAs in miRBase 8.0, plus 152 additional unpublished human miRNAs • Manufactured using GE Healthcare’s CodeLink™ 3-D Gel Matrix Technology • One color detection capability provides quantitative data and enables comparisons between experiments • Highly reproducible results (CV <10%) with superior sensitivity and specificity Evaluation of the global expression patterns of microRNAs (miRNAs)— small, highly conserved RNA molecules that have been implicated in oncogenesis, development, viral infection, and other critical biological processes —pro- vides key opportunities to identify regulatory points for various disease states and biological processes. Ambion’s mirVana miRNA Bioarrays make it easy to illuminate the mysteries of miRNA function. These ready-to-use slide-based arrays enable the profiling of human, mouse, and rat miRNA expression pat- terns in different tissues, cells, and developmental states. Shine Light on microRNA Expression Profiles Reproducibility of Differential Expression Ratios with mirVana™miRNA Bioarrays. Relative miRNA expression levels in tissues A and B were determined by analysis of each tissue on two independent mirVana™ miRNA Bioarrays and comparison of the resulting normalized signal intensities [log 2 Ratio (tissue A/tissue B)]. The experiment was performed in duplicate on two different days (Exp #1, Exp #2). Correlation of LogRatios between the two experiments was >99%, demonstrating excellent reproducibility. *Ruvkun, G. 2001. Glimpses of a tiny RNA world. Science 294(Oct. 26):797-799. 10 2 4 6 8 10 –2 –2 –4 –4 –6 –6 –8 –8 –10 –10 2 4 6 8 R 2 =0.9919 LogRatio (tissueA/tissueB) Exp #1 LogRatio (tissueA/tissueB) Exp #2 Learn how you can elucidate miRNA function at www.ambion.com/info/bioarrays For research use only. Not for use in diagnostic procedures. THE COMPLETE miRNA SOLUTION PROVIDER™ . >> DEPARTMENTS 1043 Science Online 1045 This Week in Science 1050 Editors’ Choice 1054 Contact Science 1057 Random Samples 1059 Newsmakers 1161 New Products 1162 Science Careers For related. www.qiagen.com/goto/EZ1mylab to find out more! www.sciencemag.org SCIENCE VOL 314 17 NOVEMBER 2006 1039 CONTENTS continued >> SCIENCE EXPRESS www.sciencexpress.org PHYSICS The Ground State of. Healthcare Bio-Sciences AB, a General Electric Company. Björkgatan 30, 751 84 Uppsala, Sweden. © 2006 General Electric Company - All rights reserved. GE08-06 www.sciencemag.org SCIENCE VOL 314