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1.
Transition metal complexes catalyze many important reactions that are employed in medicine, materials science, and energy production. Although high-throughput methods for the discovery of catalysts that would mirror related approaches for the discovery of medicinally active compounds have been the focus of much attention, these methods have not been sufficiently general or accessible to typical synthetic laboratories to be adopted widely. We report a method to evaluate a broad range of catalysts for potential coupling reactions with the use of simple laboratory equipment. Specifically, we screen an array of catalysts and ligands with a diverse mixture of substrates and then use mass spectrometry to identify reaction products that, by design, exceed the mass of any single substrate. With this method, we discovered a copper-catalyzed alkyne hydroamination and two nickel-catalyzed hydroarylation reactions, each of which displays excellent functional-group tolerance.  相似文献   

2.
Physics     
From massive quarks deep in the hearts of atomic nuclei to the catastrophic collapse of giant stars in the farthest reaches of the universe, from the partial realization of Einstein's dream of a unified theory of the forces of nature to the most practical applications in technology, medicine, and throughout contemporary society, physics continues to have a profound impact on man's view of the universe and on the quality of life. The author argues that the past few years, in terms of new discoveries, new insight-and the new questions-have been among the most productive in the history of the field and puts into context his selection of some of the most important new developments in this fundamental science.  相似文献   

3.
Cole JR  Cole S 《Science (New York, N.Y.)》1972,178(4059):368-375
Let us consider, then, some general conclusions that may be drawn from the findings reported in this study. The data allow us to question the view stated by Ortega, Florey, and others that large numbers of average scientists contribute substantially to the advance of science through their research. It seems, rather, that a relatively small number of physicists produce work that becomes the base for future discoveries in physics. We have found that even papers of relatively minor significance have used to a disproportionate degree the work of the eminent scientists. Although the conclusions of this paper may be reasonably clear, the implications of these data for the structure of scientific activity, at least in physics, need careful consideration.  相似文献   

4.
阐述了21世纪食品科学与工程学科人才培养目标和学生知识、能力、素质教育研究所面临的新形势、新趋势和新特点,并做出基本的分析与判断。  相似文献   

5.
[目的/意义]分析开放科学与知识产权的关系,从宏观的角度梳理开放科学发展现阶段面临的重要知识产权问题,为进一步推进开放科学中相关政策研究与制定提供参考。[方法/过程]研究主要采用文献调研、文献计量等方法,对近年来国内外与开放科学、知识产权主题相关的文献进行分析,挖掘开放科学和知识产权的关系,提炼相关知识产权热点问题。[结果/结论]开放科学与知识产权之间存在显著矛盾,但这种矛盾并非不可避免,双方应形成良性互动,建立与开放科学相适应的知识产权制度。当前开放科学中的知识产权问题主要集中在著作权与专利权方面,同时如何保障科学发现的优先权,以及数据权设立等也是研究的热点问题。  相似文献   

6.
Bok DC 《Science (New York, N.Y.)》1981,213(4511):980-982
In reassessing the role of government, many Americans have agreed that public expenditures should be curtailed. Although our universities must bear their full share of the sacrifices, some of the Administration's recent proposals would be to the detriment of the country. Drastic cuts in student aid, for example, will not encourage young people to seek the best possible education and training; reductions in federal funds for scientific instruments and facilities will mean that our laboratories will deteriorate, our accomplishments will be fewer. The success of American science has depended heavily on the talent that came from Europe at the time of World War II. Today that source has largely disappeared, and if we cannot replace it with exceptional young investigators of our own, the quality of our universities and the vitality of our science will diminish.  相似文献   

7.
It is particularly important for us not to lose sight of the fact that people have been around for a long time and that they achieved remarkable technical skills long before Western science was developed. An anonymous writer from the Food and Agriculture Organization has observed: "It is a commonplace that the fundamental discoveries which made civilization possible-fire- making, tool-making, agriculture, building, calculating, writing, money-were all apparently made outside the area which has given us the marvels of modern science" (19). The writer might well have added that it is also commonly overlooked that food technology was not suddenly developed in the 20th century but has been very much a part of the lives of people everywhere ever since they began doing more to their food than gathering it and eating it raw. Lamb's "Essay on Roast Pig" may not be an accurate account of the first conjunction of fire and food, but cooking is a rather ancient practice. Fermentation is another complicated processing technology which is a traditional part of most cultures, particularly those in warm climates-beer, yogurt, cheese, the fish pastes and sauces of Asia, the palm wine of Africa, and soy sauce, are butsome examples. Native Americans, besides accomplishing marvels in plant genetics and crop development, also developed water extraction methods for treating acorns to render the flour palatable and edible, and the alkali method of processing maize. Furthermore, they developed a cure for scurvy-by making a water extraction of pine needles which are rich in ascorbic acid-long before it was first reported by Jacques Cartier in the 16th century. Similarly, calcium-deficient diets of pregnant and nursing women were traditionally successfully supplemented by calcium-rich powdered deer antlers in northern China. Among the Chinese and Greeks, goiter was cured by eating certain kinds of seaweed centuries before the disease was traced to a lack of iodine, and Kenyans learned to suck salt-rich earth to avoid salt depletion symptoms after arduous exertion in tropical heat long before "modern science" learned why (20). The enumeration of examples could go on, but this was not meant to be an essay in folklore. The point is that all so-called primitive societies developed technologies, techniques, and a store of practical knowledge of a wide range of sophistication, by what must be admitted to be the scientific method, and neither their accomplishments and skills nor those of societies "en voie de développement" should be ignored or discounted. We are confident that modern food science and technology has much to contribute to helping the food-deficit nations eat adequately. First, we must find a way of using the best of Western technology without losing sight of the reality of the situation in the third world and without failing to take into account, better than we have done so far, the secondary and tertiary implications of the changes suggested. Second, we must encourage the examination of local problems in terms of the use and improvement of local technologies which are often quite sophisticated and the result of centuries of development. And third, we must inject a greater component of cultural awareness in the education of students to make them more creative in their application of scientific knowledge to local problems and more adaptable to the conditions that exist in developing countries. We should not lose sight of the fact that because of the precarious nature of their food supply, very often developing countries have much more rigid rules governing the production, preparation, and consumption of food than usually is the case in food-surplus societies, and disturbing these rules is a very serious matter. The time is past when "West is best" can be taken for granted; "adapt and adopt" is surely less offensively arrogant and much more to the point.  相似文献   

8.
Zonal centrifuges and other separation systems   总被引:5,自引:0,他引:5  
This discussion has included only a partial list of the systems now under development at Oak Ridge as part of the feasibility studies for the Molecular Anatomy Program. It is evident that we are still in the "Robert Goddard" phase of this work. It may not be premature, however, to suggest several conclusions.Biomedical scientists are discouraged on discovering that developmental efforts cost more, by one or two orders of magnitude, than pure research. In part this is because the full cost of development is generally shown, while in pure research some of the costs may be hidden, or the funds supplied by several sources. Regardless of the reason, the fact remains that development is expensive, as is well understood in nuclear physics and space science. The role and mission of the large national laboratories, and the kinds of research that should be done in them, have been discussed by Weinberg (63). The studies described here were in part stimulated by his ideas. We have been unable to find an environment outside a large national laboratory where a program like the Molecular Anatomy Program could be undertaken at the present rate. It appears that programs which attempt to make use of the multidisciplinary approach characteristic of national laboratories should be carefully designed and should evolve experimentally. There is less chance of success when a program is an administrative invention than when it evolves from scientific invention and discovery. It has been pointed out (64) that most program decisions in science are secret decisions in the sense that the scientific community as a whole does not participate in them. If a choice is to be made at some future time between large-scale expenditures for exploring space, for developing new weapons systems, for constructing new accelerators, for designing large reactors, or for systematically developing methods to explore the molecular basis of human disease, then we will need sufficient information to evaluate each alternative fully, and the information should be generally available. It appears desirable, therefore, to allow the Molecular Anatomy Program to proceed to a point where the full range of its contributions and its inherent limitations may be seen. A rational choice may then be made.  相似文献   

9.
Much of what needs to be changed in U.S. industry involves close ties to manufacturing, design for manufacturability, a rapid design cycle, and up-to-date technical knowledge on the part of the engineers themselves. Being up-to-date requires conscious company effort. Traveling to meetings, reading the technical literature, and being a part of the engineering community are necessities if we are to compete with others who make these efforts and are thus better able to incorporate technical change rapidly into their own products. Outside the product improvement cycle, a research (as opposed to development) organization in industry must have close ties to development and manufacturing in order to succeed. With these close ties, researchers can understand the progress of the cycle and can introduce new steps at the appropriate time and in an acceptable form. A research organization that surmounts the internal barriers and becomes an accepted contributor to the development and manufacturing process can, because of its greater technical depth, its scientific knowledge, and its close ties with the university world, become a forceful initiator of progress. It is more difficult, in our opinion, to make these contributions from a university base and from government laboratories as they are now constituted. Much has been said by industry and government leaders about reforming the educational system and strengthening the national science base-things that help build a strong foundation. A strong science base supplies a vast storehouse of new ideas, and a good educational system provides engineers and manufacturing workers with knowledge; but strength here cannot make up for inadequacies in the functioning of the development and manufacturing cycle. The United States must learn to succeed, not only in the ladder type of innovation in which a wholly new idea from science creates a wholly new product (the science-dominated process at which we have succeeded in the past), but also in the rapid, cyclical, engineer-dominated process of incremental product improvement. Neither process is a substitute for the other; we need both.  相似文献   

10.
Millions of patients may benefit from the applications of stem cell research, although there is disagreement about whether public funds should be used to develop the science. Patients have been key to winning political support. Acting as advocates, they have contended that public investment will speed the research and bring accountability to biomedical technology. A political dispute about the new research, which holds the potential for cures to devastating diseases and to foster healthy aging, shows the need to respect public sensibilities and to court public approval, as well as the importance of involving patients in debates where the methods of biomedical discoveries and ethical beliefs collide.  相似文献   

11.
Because most cooperative societies are despotic, it has been difficult to test models of egalitarianism. Female African lions demonstrate a unique form of plural breeding in which companions consistently produce similar numbers of surviving offspring. Consistent with theoretical predictions from models of reproductive skew, female lions are unable to control each other's reproduction because of high costs of fighting and low access to each other's newborn cubs. A female also lacks incentives to reduce her companions' reproduction, because her own survival and reproduction depend on group territoriality and synchronous breeding. Consequently, female relationships are highly symmetrical, and female lions are "free agents" who only contribute to communal care when they have cubs of their own.  相似文献   

12.
We have identified 21 millisecond pulsars (MSPs) in globular cluster Terzan 5 by using the Green Bank Telescope, bringing the total of known MSPs in Terzan 5 to 24. These discoveries confirm fundamental predictions of globular cluster and binary system evolution. Thirteen of the new MSPs are in binaries, of which two show eclipses and two have highly eccentric orbits. The relativistic periastron advance for the two eccentric systems indicates that at least one of these pulsars has a mass 1.68 times greater than the mass of the Sun at 95% confidence. Such large neutron star masses constrain the equation of state of matter at or beyond the nuclear equilibrium density.  相似文献   

13.
高校绿色化学实验室探讨   总被引:1,自引:0,他引:1  
高校化学实验室作为一种特殊形式的污染源,不可避免地对环境造成了污染。如何消除或尽量减少化学污染,实现化学实验室的绿色化,是实验教学人员研究的新课题。针对基础化学实验室的污染问题,运用绿色化学思想和原则,从精选实验内容,改进实验方式,科学处理实验室废弃物等方面,对实验室的绿色化建设进行了探索和实践。  相似文献   

14.
Murine leukemia viruses (MLVs), including xenotropic-MLV-related virus (XMRV), have been controversially linked to chronic fatigue syndrome (CFS). To explore this issue in greater depth, we compiled coded replicate samples of blood from 15 subjects previously reported to be XMRV/MLV-positive (14 with CFS) and from 15 healthy donors previously determined to be negative for the viruses. These samples were distributed in a blinded fashion to nine laboratories, which performed assays designed to detect XMRV/MLV nucleic acid, virus replication, and antibody. Only two laboratories reported evidence of XMRV/MLVs; however, replicate sample results showed disagreement, and reactivity was similar among CFS subjects and negative controls. These results indicate that current assays do not reproducibly detect XMRV/MLV in blood samples and that blood donor screening is not warranted.  相似文献   

15.
The peroxisomal matrix oxidase,catalase and peroxidase are imported peroxisomes through the shuttling receptors,which regulates the cellular oxidative homeostasis and function.Here,we report that PTS1 shuttling receptor FvPex5 is involved in the localization of PTS1,utilization of carbon sources and lipids,elimination ROS,cell wall stress,conidiation,fumonisin B1(FB1) production,and virulence in maize pathogen Fusarium verticillioides.Significantly,differential expression o...  相似文献   

16.
While the question of whether the Arthropoda represent more than one phylum of animals is debatable, the jointed exoskeleton, a fundamental feature of arthropods, evolved independently in two groups that shared a worm-like common ancestor. The two major branches of Arthropoda, the primitively marine TCC and the primitively terrestrial (with one exception) Uniramia, independently arrived at arthropodization as the solution to the same problems of adaptation of the body mechanical system. New discoveries on trilobite anatomy show the unity of TCC as a group that shared a trilobite-like ancestor near the beginning of the Cambrian. With change in the constituency of Arthropoda through geologic time, the ways in which it would be categorized as a taxonomic group have also changed. The seeming isolation of the major modern arthropod groups is in large part an artifact of extinction of primitive intermediate forms such as trilobites which, in the Early Paleozoic, made the Arthropoda more diverse in basic modes of body organization than the group is at present. The appearance of fossilizable hard parts in arthropods resulted from shift in supporting function from the body cavity, primitively a hydrostatic skeleton, to the cuticle, which came to be strengthened in becoming an exoskeleton. Energetic efficiency, more than protection from predators or evolutionary size increase in itself, was probably the impetus behind the transition. On the scale provided by the general evolutionary trend toward progressive specialization of segments, TCC became arthropodized at earlier stages than did Uniramia. Among TCC, the shift may have been driven by the evolution of locomotory and feeding mechanisms that were exclusively geared to an aqueous medium.  相似文献   

17.
Replication and mutation are necessary elements of evolution, and some properties of self-replicating molecules (replicators) can be explored with synthetic structures. Selection and evolution at the molecular level require systems capable of competition and inheritable change. These phenomena have now been observed with synthetic molecules. Two such molecules were prepared having sufficient structural similarity that they catalyzed each other's formation as well as their own. One of the replicators bears a photochemically active function that is cleaved on irradiation. The resulting species is more effective at replication than the original and rapidly takes over the system's resources.  相似文献   

18.
A major strategy in the creation of sustainable economies is the establishment of alternative market institutions, such as fair trade and local market systems. However, the dynamics of these alternative markets are poorly understood. What are the rules of behavior by which these markets function? How do these markets maintain their separate identity as “alternative”: apart from the conventional (“free”) market system? Building on Lyson’s notion of civic agriculture, we argue that alternative markets maintain themselves through civic engagement. However, we argue that the civically-engaged practices of alternative markets are poorly understood. We seek, therefore, to begin a conversation about the everyday forms of civic engagement in alternative practice and to do this we introduce a few useful conceptual tools. Building upon ideas in science studies about the collaboration of scientists (Hess, Alternative pathways in science and industry, 2007) we argue that civic markets have their own “market fields” and “modes of governance” (Bulkeley et al., Environment and Planning A 39:2733–2753, 2007), their own fields of social interaction in which rules of behavior become stabilized and determine how the market works. The creation of a social field also requires the demarcation of boundaries, referred to in the science studies literature as “boundary work” (Gieryn, Cultural boundaries of science: Credibility on the line, 1999). We apply the idea of boundary work to understand how alternative market actors maintain boundaries between alternative and conventional markets. Finally, studies of collaboration in science have often centered on the object created through these interactions, an object that is partially material and partially a product of knowledge, what (Rheinberger, Toward a history of epistemic things: Synthesizing proteins in the test tube, 1997) calls an “epistemic object.” We use this idea to understand that the creation of alternative objects of exchange, such as organic food, are epistemic objects in that they combine both particular materialities and particular ways of knowing. Using these concepts, we will carry out a close analysis of the mode of governance in the national organic market, looking specifically a recent governance crisis in organic agriculture known as the Harvey lawsuit.  相似文献   

19.
There is no need to summarize the features of this simplified model, which describes the manner in which modern science was transmitted to the lands beyond Western Europe. The graph of Fig. 1 and the examples drawn from science in various lands should have made them clear. It may be in order, however, to reiterate that there is nothing about the phases of my model that is cosmically or metaphysically necessary. I am satisfied if my attempt will interest others to go beyond my crude analysis and make a systematic investigation of the diffusion of Western science throughout the world. Such an investigation would include a comparative appraisal of the development of science in different national, cultural, and social settings and would mark the beginnings of truly comparative studies in the history and sociology of science. The present lack of comparative studies in these disciplines can be attributed to the widespread belief that science is strictly an international endeavor. In one sense this is true.As Sir Isaac Newton remarked in his Principia (49), "the descent of stones in Europe and in America" must both be explained by one set of physical laws. Yet, we cannot ignore the peculiar environment in which members of a national group of scientists are trained and carry on their research. While I do not hold with the Nazi theorists that science is a direct reflection of the racial or national spirit (50), neither do I accept Chekhov's dictum (51) that "there is no national science just as there is no national multiplication table. . . ." In emphasizing the international nature of scientific inquiry we have forgotten that science exists in a local social setting. If that setting does not decisively mold the conceptual growth of science, it can at least affect the number and types of individuals who are free to participate in the internal development of science. Perhaps the effect is more profound; only future scholarship can determine the depth of its influence.  相似文献   

20.
Newt Gingrich introduces the concept of an "opportunities-based budget", as an approach to federal research and development funding. Policy-makers should not frame the debate on science funding in terms of percentage of increase. Rather, a systematic analysis of the promise of opportunities should be conducted and the funds allotted accordingly. This article is a call to rethink how lawmakers are funding the discoveries upon which future generations will rely.  相似文献   

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