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| 1 | THEORY OF DIELECTRIC ELASTOMERS显示文摘In response to a stimulus,a soft material deforms,and the deformation provides a function.We call such a material a soft active material (SAM).This review focuses on one class of soft active materials: dielectric elastomers.When a membrane of a dielectric elastomer is subject to a voltage through its thickness,the membrane reduces thickness and expands area,possibly straining over 100%.The dielectric elastomers are being developed as transducers for broad applications,including soft robots,adaptive optics,Braille displays,and electric generators.This paper reviews the theory of dielectric elastomers,developed within continuum mechanics and thermodynamics,and motivated by molecular pictures and empirical observations.The the-ory couples large deformation and electric potential,and describes nonlinear and nonequilibrium behavior,such as electromechanical instability and viscoelasticity.The theory enables the finite element method to simulate transducers of realistic configurations,predicts the efficiency of elec-tromechanical energy conversion,and suggests alternative routes to achieve giant voltage-induced deformation.It is hoped that the theory will aid in the creation of materials and devices. | Zhigang Suo (School of Engineering and Applied Sciences,Kavli Institute for Nanobio Science and Technology,Harvard University,Cambridge,MA 02138,USA) | 2010 | Acta Mechanica Solida Sinica2010，23，6： | 37 |
| 2 | Epigenetic regulation: methylation of histone and non-histone proteins显示文摘Histone methylation is believed to play important roles in epigenetic memory in various biological processes. However, questions like whether the methylation marks themselves are faithfully transmit- ted into daughter cells and through what mechanisms are currently under active investigation. Previ- ously, methylation was considered to be irreversible, but the recent discovery of histone lysine de- methylases revealed a dynamic nature of histone methylation regulation on four of the main sites of methylation on histone H3 and H4 tails (H3K4, H3K9, H3K27 and H3K36). Even so, it is still unclear whether demethylases specific for the remaining two sites, H3K79 and H4K20, exist. Furthermore, be- sides histone proteins, the lysine methylation and demethylation also occur on non-histone proteins, which are probably subjected to similar regulation as histones. This review discusses recent pro- gresses in protein lysine methylation regulation focusing on the above topics, while referring readers to a number of recent reviews for the biochemistry and biology of these enzymes. | LAN Fei1 & SHI Yang 2 1 Department of Biology, Constellation Pharmaceuticals, 148 Sidney Street, Cambridge, MA 02139, USA 2 Department of Pathology, Harvard Medical School, 77 Ave Louise Pasteur, Boston MA, 02115, USA | 2009 | Science China(Life Sciences)2009，52，4： | 27 |
| 3 | Rapid mitogen-activated protein kinase activation by transforming growth factor α in wounded rat intestinal epithelial cells显示文摘RapidmitogenactivatedproteinkinaseactivationbytransforminggrowthfactorαinwoundedratintestinalepithelialcelsMichaelGkee,Michi... | Michael Gke, Michiyuki Kanai, Kathryn Lynch Devaney, and Daniel K. Podolsky Gastrointestinal Unit, Department of Medicine, and Center for the Study of Inflammatory Bowel Disease, Massachusetts General Hospital and Harvard Medical School, Boston, Massa | 1998 | World Journal of Gastroenterology1998，4，3： | 14 |
| 4 | Carcinogenic potential of duodenal reflux juice from patients with long-standing postgastrectomy显示文摘AIM To determine, whether study on thecarcinogenic potential of reflux juice frompatients with remote gastrectomy could clarifythe inherent relationship between duodenalreflux and gastric stump cancer.METHODS A total of 37 reflux juice samples(13 Billroth T, 24 Billroth Ⅱ ) were employed inthe present study. A two- stage transformationassay using BALB/c 3T3 cells was carried out totest the initiating or promoting activity of thesesamples.RESULTS Two of 18 (11.1%) reflux samplesexerted initiating activities, whereas 9/19(47.4%) samples enhanced the MNNG-initiafingcell transformation, suggesting the duodenalreflux juice might more frequently possess thetumor-promoter activity (P = 0. 029). In addition,there was no difference in initiating activities ofthe samples irrespective of surgical procedures(P=0.488), while Billroth Ⅱ samples exhibitedstronger tumor-promoter activity than Billroth Ⅰsamples (P = 0.027). Furthermore, the promoteractivities were well correlated with thehistological changes of the stomas (rs = 0.625,P = 0.004), but neither their cytotoxicities norinitiating activities had this correlation( Probabilities were 0.523 and 0.085,respectively).CONCLUSION The duodenal reflux juice frompatients with remote postgastrectomy did havecarcinogenic potential, and suggested thattumor-promoting activity should principallyaccount for the high incidence of gastric cancerin gastrectomy patients. In contrast, it isdifficult to explain the high stump-cancerincidence with the 'N-nitroso compounds'theory-a popular theory for the intact stomachcarcinogenesis, and it seemed to be justified tofocus chemoprevention of this cancer on thetumor-promoting potential of reflux juice. | Zhe Fu Ma~1 Zhong Yu Wang~1 Jun Ran Zhang~2 Peng Gong~1 Hai Long Chen~1 ~1Departrnent of General Surgery,First Hospital,Dalian Medical University,Dalian 116011,China ~2Department of Radiation Oncology,Massachusetts General Hospital and Harvard Medical School,Charlestown,MA 02129,USADr.Zhe Fu Ma graduated from Shanxi Medical College in 1993,nowPh.D.,M.D.in Department of Surgery,Dalian Medical University,majoring gastroenteric cancer,having 4 papers published.Correspondence to:Dr.Zhe Fu Ma.Department of General Surgery,First Hospital,Dalian Medical University,Dalian 116011,China Tel.0086-411-4720334 | 2001 | World Journal of Gastroenterology2001，7，3： | 9 |
| 5 | Intrinsic control of axon regeneration显示文摘Spinal cord injury disrupts the connections between the brain and spinal cord, often resulting in the loss of sensory and motor function below the lesion site. The most important reason for such permanent functional deficits is the failure of injured axons to regenerate after injury. In principle, the functional recovery could be achieved by two forms of axonal regrowth: the regeneration of lesioned axons which will reconnect with their original targets and the sprouting of spared axons that form new circuits and compensate for the lost function. Our recent studies reveal the activity of the mammalian target of rapamycin (mTOR) pathway, a major regulator of new protein synthesis, as a critical determinant of axon regrowth in the adult retinal ganglion neurons[1]. In this review, I summarize current understanding of the cellular and molecular mechanisms that control the intrinsic regenerative ability of mature neurons. | Zhigang He F.M. Kirby Neurobiology Center, Children’s Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA. | 2010 | The Journal of Biomedical Research2010，24，1： | 6 |
| 6 | Smashing Tissue Extraction and GC Analysis of Active Fatty Acids from Oil Cake of Perilla Seeds显示文摘Objective To optimize the extraction technology of perilla seeds oil from the oil cake of perilla seeds(OCPS)by using the contents of active fatty acids as evaluation standard.Methods The fatty acids were extracted from OCPS,the residue of perilla seeds after cold-press,by smashing tissue extraction(STE),the new technology selected through comparing with classical leaching extraction(LE),Soxhlet extraction(SE),ultrasonic extraction(UE),and supercritical-CO2 fluid extraction(SFE).For optimized condition of STE,orthogonal test was designed and completed.The contents of five fatty acids in extracted oil and OCPS were determined by GC.Results The optimized extraction parameters were smashing for 1.5 min under extraction power of 150 W and 1:6 of the material/solvent ratio.The contents of five fatty acids in the oils extracted by five techniques from OCPS and determined by GC were as follows:α-linolenic acid(41.12%-51.81%),linoleic acid(15.38%-16.43%),oleic acid (18.93%-27.28%),stearic acid(2.56%-4.01%),and palmitic acid(7.38%-10.77%).Conclusion The results show that STE is the most efficient technology with the highest yield(LE:0.57%;SE:1.03%;UE:0.61%;SFE:0.80%;STE: 1.17%)and shortest time(LE:720 min;SE:360 min;UE:30 min;SFE:120 min;STE:1.5 min)among five tested extraction technologies.It is first reported using STE to extract herbal oil enriched with active fatty acids. | SUN Yan-ling1,LIU Yan-ze2,3,XIAO Han4,WEI Ying-feng4,ZHAO Yu-qing1,5 1.Shenyang Pharmaceutical University,Shenyang 110006,China 2.Bio-organic and Natural Product Laboratory,MRC 311,McLean Hospital/Harvard Medical School,Belmont,MA 02478,USA 3.Institute of Medicinal Plant Development,Chinese Academy of Medical Sciences,Beijing 100193,China 4.Liaoning Jiashi Nutritional Plant Oil Development Co.Ltd.,Shenyang 110035,China 5.Key Laboratory of Structure-Based Drug Design&Discovery,Shenyang Pharmaceutical University,Ministry of Education,Shenyang 110016,China | 2011 | Chinese Herbal Medicines2011，3，1： | 5 |
| 7 | Smashing Tissue Extraction and HPLC Determination of Paclitaxel and 10-Deacetylbaccatin from Taxus x media显示文摘Objective To optimize the extraction technology of Taxus x media by using the contents of Paclitaxel and 10-deacetylbaccatin(10-DAB) ,two representative active diterpene alkaloids of taxane type from T.x media,as evaluation standard.Methods The smashing tissue extraction(STE) of Paclitaxel and 10-DAB from T.x media,was investigated by comparing with ultrasonic extraction(UE) which was one of the modern technologies of extraction.Results STE was more efficient than UE,and the contents of 10-DAB and Paclitaxel in the extracts obtained by STE were higher than those by UE.Conclusion STE is a fast,high-performance,and energy-saving technology for the extraction of diterpene alkaloids of taxane type.STE also provides a simple,component-safe,workable,and highly efficient method for the extraction of active natural product. | LIU Yan-ze1,2,GAO Wen-qin3,WANG Ji-wen4,ZHANG Yu3,ZHAO Yu-qing4,5 1.Institute of Medicinal Plant Development,Chinese Academy of Medical Sciences,Beijing 100193,China 2.Bio-Organic and Natural Product Laboratory,McLean Hospital/Harvard Medical School,MA 02478,USA 3.Shenyang Pharmaceutical University,Shenyang 110006,China 4.Shenyang Tianfeng Bioengineer Technology Co.,Ltd.,Shenyang 110015,China 5.Key Laboratory of Structure-Based Drug Design & Discovery,Ministry of Education,Shenyang Pharmaceutical University,Shenyang 110016,China | 2011 | Chinese Herbal Medicines2011，3，3： | 4 |
| 8 | Nonlinear dynamics of self-oscillating polymer gels显示文摘Self-oscillating polymer gels driven by Belousov-Zhabotinsky (BZ) chemical reaction are a new class of functional gels that have a wide range of potential applications (e.g., autonomously functioning membranes, actuate artificial muscles). However, the precise control of these gels has been an issue due to limited investigations of the influences of key system parameters on the characteristics of BZ gels. To address this deficiency, we studied the self-oscillating behavior of BZ gels using the nonline-ar dynamics theory and an Oregonator-like model, with focus placed upon the influences of various system parameters. The analysis of the oscillation phase indicated that the dynamic response of BZ gels represents the classical limit cycle oscillation. We then investigated the characteristics of the limit cycle oscillation and quantified the influences of key parameters (i.e., ini-tial reactant concentration, oxidation and reduction rate of catalyst, and response coefficient) on the self-oscillating behavior of BZ gels. The results demonstrated that sustained limit cycle oscillation of BZ gels can be achieved only when these key pa-rameters meet certain requirements, and that the pattern, period and amplitude of the oscillation are significantly influenced by these parameters. The results obtained in this study could enable the controlled self-oscillation of BZ gels system. This has several potential applications such as controlled drug delivery, miniature peristaltic pumps and microactuators. | WANG PengFei1, ZHOU JinXiong1, LI MeiE2, XU Feng1,3 & LU TianJian1 1 Biomedical Engineering and Biomechanics Center, SV Laboratory, Xi’an Jiaotong University, Xi’an 710049, China 2 School of Materials Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China 3 HST Center for Biomedical Engineering, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, 510660, USA | 2010 | Science China(Technological Sciences)2010，53，7： | 3 |
| 9 | Stathmin is overexpressed in malignant mesothelioma显示文摘 | HARVARD C YOU L | 2007 | Anticancer Res2007，27，1： | 1 |
| 10 | Economic growth and land-use changes:the declining amount of wilderness land in Norway显示文摘 | ANDERS SKONHOFT HARVARD SOLEMN | 2001 | Ec-ological Economics2001，37，： | 1 |
| 11 | Adefinition of irreversible coma 显示文摘 | Ad Hoc Committee of the Harvard Medical School to examine the definition of brain death | 1968 | JAMA1968，205，： | 1 |
| 12 | E-Books in Libraries:A Briefing Document Developed in Preparation for a Workshop on E-Lending in Libraries显示文摘 | Harvard University-Berkman Center for Internet & Society | 2012 | Berkman Center Research Publication2012，，15： | 1 |
| 13 | Stathmin is overex- pressed in malignant mesothliom显示文摘 | Kim JY Harvard C You L | 2007 | Anticancer Res2007，27，1： | 1 |
| 14 | Genome-wide association analysis identifies loci for type 2 diabetes and triglyceride levels显示文摘 | Diabetes Genetics Initiative of Broad Institute of Harvard and MIT Lurid University and Novartis Institutes of BioMedical Research Saxena R Voight BF | 2007 | Science2007，316，5829： | 1 |
| 15 | RNA and Protein Requirements for Eukaryotic Selenoprotein Synthesis显示文摘Selenium has been recognized as an essential nutrient in animals since the 1950s. Demonstration of the role of dietary selenium in protection from oxidative stress foIlowed in the early 1970s, and was largely attributed to its presence as an integral part of cellular glutathione peroxidase. However, the functions of this enzyme did not explain many of the other effects of selenium deficiency. The identification of other mammalian selenoproteins during the last few years has provided new insights into the functions of this trace nutrient. The discovery that type 1 deiodinase (D1) is a selenoenzyme, in addition to unveiling an essential role for selenium in thyroid hormone action, has had more far-reaching implications. Studies of this protein opened the door for investigation of the requirements for eukaryotic selenoprotein synthesis,and the features that distinguish this pathway from the corresponding prokaryotic pathway.Selenium is present in a number of prokaryotic and eukaryotic proteins in the form of the unusual amino acid, selenocysteine. Incorporation of selenocysteine into these proteins requires a novel translation step in which UGA specifies selenocysteine insertion. Since UGA codons are typically recognized as translation stop signals, an intriguing question is raised: How does a cell recognize and distinguish a UGA selenocysteine codon from a UGA stop codon? In this review, we will focus on what is known about selenocysteine incorporation in eukaryotes, briefly summarizing initial studies and discussing a few recent advances in our understanding of this unique 'recoding' | MARLA J. BERRY GLOVER W. MARTIN Ⅲ, AND SUSAN C. LOW(Thyroid Division, Department of Medicine, Brigham and Women’s Hospital Program in Biological and Biomedical Sciences, Harvard Medical School, Boston, Massachusetts 02115,USA) | 1997 | Biomedical and Environmental Sciences1997，10，2： | 1 |
| 16 | Ethnic differ- ences translate to inadequacy of high-risk screening for gestational diabetes mellitus in an Asian population:a co- hort study显示文摘 | Yap-Seng C Shirong C Harvard L | 2014 | BMC Pregnancy Childbirth2014，14，： | 1 |
| 17 | FINE PARTICULATE AIR POLLUTION: EPIDEMIOLOGIC BASIS FOR AIR QUALITY STANDARDS显示文摘In proposing a new ambient air quality standard for fine particulate air pollution in 1997, the U.S. Environmental Protection Agency was responding to a wealth of epidemiologic evidence. At the same time, it was recognized that there was little supporting evidence from toxicologic or controlled human exposure studies. The epidemiologic findings were questioned as only statistical associations without a plausible biological mechanism or an identified causal agent in the complex mix of pollutants characterized as fine particles. In response to these weaknesses in the scientific evidence, a series of research initiatives have been undertaken in exposure assessment, controlled animal and human exposures, and assessments of free-living populations. Key papers have been subjected to comprehensive review and replication. It is now four to seven years since the seminal papers suggesting adverse health effects of fine particles were published. Have these results held up over time? Have they been confirmed by other investigators in other populations? Do we have insights into the biologic mechanisms? Have the specific toxic characteristics of particles been identified? | Douglas W. Dockery Harvard School of Public Health, 665 Huntington Ave, Boston, MA 02115 USA | 2001 | 安全2001，22，3： | 1 |
| 18 | Genome-wide association analysis identifies loci for type 2 diabetes and triglyceride levels 显示文摘 | Diabetes Genetics Initiative of Broad Institute of Harvard and MIT Lund University and Novartis Institutes for BioMedical Research | 2007 | Science2007，316，： | 1 |
| 19 | Developments in the Law: Academic Freedom 显示文摘 | The Harvard Law Review Association | 1968 | Harvard Law Review1968，，5： | 1 |
| 20 | How can clusters sustain performance? The role of network strength network openness, and en- vironmental uncertainty 显示文摘 | The Social Structure of MA: Harvard University Eisingerich A B | 2010 | Research Policy2010，39，2： | 1 |
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