检索结果-南通市图书馆

Milestone of the meridian science──970th anniversary of the Chinese Bronze Statue of Meridian

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1998年第5期43卷 353-362页

作者： ZHANG Renji college of life sciences, peking university, beijing 100871, china college of life sciences Peking University Beijing 100871 China

For more than a thousand years, Chinese people were aware of the transmitted sensations by the application of needles on the body surface. This practice is called acupuncture. Acupuncture had been recorded and transcribed in writings and in drawings, until finally the acupoints were inscribed onto a bronze statue. The bronze statue was called the Meridian Figure. Deeply embodied in the bronze statue is a tripartite confrontation-prism representation of the humans body. This concept was a great scientific achievement in ancient china. The author traces the history of Meridian science described in traditional Chinese medical terms. Then he explores a clear analogy of the meridian pathway (MP) phenomenon. In a model system, by using a simple segmental in vertebrate, certain parallels can be demonstrated with the meridian concept. For example, the author demonstrated a clear correlation rule among the central mechano-sensory channels, and characteristics of positional discrimination in individual nerve cells from different receptive field inputs. The evidence suggests that the MP phenomenon is an objective neurobiological response. To clarify the research objective in this paper, the author suggests that the MP is a bi-directional pathway along which a positional message signal is transmitted. This phenomenon is evoked by physical stimulation, transmitted linearly across the human body segments, and is perceived by the brain. The MP consists of low resistance paths, is connected by the liquid media contained in the apposite membranous structure. At the cellular level, the regulation functions of MP must pass through along this low resistance path. Two aspects of the modern Meridian research are the functional regulation and the mechanism of intercellular liquid modulation at the nanometer level.

关键词： meridian pathway tripartite confrontation-prism coordinate position discriminative recognition apposite membranous structure.

INFINITE ELEMENT METHOD FOR THE EXTERIOR PROBLEMS OF THE HELMHOLTZ EQUATIONS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2000年第6期18卷 657-672页

作者： Lung-an Ying (School of Mathematical sciences, peking university, beijing 100871, china) 北京大学北京 100871

There are two cases of the exterior problems of the Helmholtz equation. If λ ≥ 0 the bilinear form is coercive, and if λ < 0 it is the scattering problem. We give a new approach of the infinite element method, which enables us to solve these exterior problems as well as corner problems. A numerical example of the scattering problem is given. [ABSTRACT FROM AUTHOR]

关键词： Helmholtz equation exterior problem infinite element method

Biotic communities of the marine ecosystem in Meizhou Bay

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental sciences 1996年第1期8卷 48-56页

作者： Ren Jiuchang Cai Xiaoming (Center of Environmental sciences,peking university, beijing 100871,china)Chen Bin(college of life sciences, peking university, beijing 100871, china )Li Peng(college of Chemistry and Molecular Engineering, peking university, Bei Ctr of Envmtl Sci Peking Univ Beijing China China

The current situation of biotic communities in Meizhou Bay is presented in this *** species composition,seasonal variation,and distribution of phytoplankton,zooplankton, red tide organisms,fishes,and benthos in Meizhou Bay were investigated,and the content of chlorophyll a and primary production and their seasonal variation were also *** water quality of Meizhou Bay was monitored by measuring the density of Escherichia coli. Results reveal that there is a great variety of species in Meizhou Bay and the water in Meizhou Bay is *** the individual numbers of various organisms are very low, especially those of ***,there are more than 40 species of red tide organisms and there exist opportunities of red tides between May and *** these demand cautious be taken in the future development of this area although it has great environment capacity.

关键词： biotic community marine ecosystem Meizhou Bay.

GM-CSF-induced Ca_(2+) -activated non-voltage-dependent inwardly rectifying K_+ channel in murine peritoneal exudate macrophages

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第11期42卷 947-952页

作者： ZHANG Xiaofeng, FENG Meifu, WU Caihong and ZHOU Pei’aiState Key Laboratory of Biomembrane and Membrane Biotechnology, Chinese Academy of sciences, beijing 100080, china 1 . In-stitute of Zoology, Chinese Academy of sciences, beijing 100080, china 2 college of life sciences, peking university, beijing 100871, china State Key Laboratory of Biomembrane and Membrane Biotechnology Chinese Academy of Sciences Beijing 100080 China

GRANULOCYTE-MACROPHAGE colony-stimulating factor(GM-CSF),a member in the family ofglycoprotein cytokines,can not only act to stimulate proliferation of immature progenitors,butalso enhance differentiated functions of mature effector *** has two kinds of biologicaleffects on mature effector cells,*** effect and indirect *** latter is also

关键词： K+ channel patch clamp GM-CSF macrophage.

Nuclear apoptosis induced by isolated mitochondria

在线全文

学校读者我要写书评

暂无评论

Cell Research 2000年第3期10卷 221-232页

作者： JIANG ZHENG FAN, YUN ZHAO, XIA HONG, ZHONG HE ZHAI (college of life sciences, peking university, beijing, 100871 china) collegeoflifesciences PekingUniversityBeijingChina.

We isolated and purified mitochondria from mouse livers and spinach leaves. When added into egg extracts of Xenopus laevis, they caused nuclei of mouse liver to undergo apoptotic changes. Chromatin condensation, margination and DNA ladder were observed. After incubating isolated mitochondria in some hypotonic solutions, and centrifuging these mixtures at high speed, we got mitochondrial supernatants. It was found that in the absence of cytosolic factor, the supernatant alone was able to induce apoptotic changes in nuclei. The effective components were partly of protein. DNA fragmentation was partly inhibited by caspase inhibitors AC-DEVD-CHO and AC- YVADCHO. Meanwhile, caspase inhibitors fully blocked chromatin condensation. Primary characterization of the nuclear endonuclease(s) induced by mitochondrial supernatants was also conducted. It was found that this endonuclease is different from endonuclease G, cytochrome c-induced nuclease, or Ca2+-activated endonuclease.

关键词： Mitochondria supernatant apoptosis egg ex- tract nuclei DNA cleavage.

BRILL-NOETHER MATRIX FOR RANK TWO VECTOR BUNDLES

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2002年第4期23卷 531-538页

作者： TAN XIAOJIANGSchool of Mathematical sciences, peking university, beijing 100871, china School of Mathematical sciences Peking University Beijing 100871 China

Let X be an arbitrary smooth irreducible complex projective curve, E (?)X a rank two vector bundle generated by its sections. The author first represents ?as a triple {D1,D2,f}, where D1 , D2 are two effective divisors with d = deg(D1) + deg(D2), and f ∈ H?X, [D1] |D2) is a. collection of polynomials. E is the extension of [D2] by [D1] which is determined by f. By using / and the Brill-Noether matrix of D1+D2, the author constructs a 2g × d matrix WE whose zero space gives Im{H0(X,[D1]) (?) H0(X, [D1] |D1)}(?) Im{H?X, E) (?) H0(X,[D2]) (?) H0(X, [D2]|D2)} From this and H0(X,E) = H0(X,[D1]) (?)Im{H0(X,E) (?) H0(X, [D2])}, it is got in particular that dimH0(X, E) = deg(E) - rank(WE) + 2.

关键词： Brill-Noether matrix Vector bundle Effective divisor

THE PHYSICAL ENTROPY OF SINGLE CONSERVATION LAWS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 1998年第5期16卷 437-444页

作者： (Department of Mathematics, peking university, beijing 100871, china) beijing Univ Dept Math Beijing 100871 Peoples R China

By means of the comparisons with the formulas in statistical mechanics and thermodynamics, in this paper it is demonstrated that for the single conservation law partial derivative(t)u + partial derivative(x)f(u) = 0, if the flux function f(u) is convex (or concave), then, the physical entropy is S = -f(u); Furthermore, if we assume this result can be generalized to any f(u) with two order continuous derivative, from the thermodynamical principle that the local entropy production must be non-negative, one entropy inequality is derived, by which the O.A. Olejnik's famous E- condition can be explained successfully in physics.

关键词： conservation laws entropy entropy production

Soluble protein and acid phosphatase exuded by ectomycorrhizal fungi and seedlings in response to excessive Cu and Cd

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental sciences 2009年第12期21卷 1667-1672页

作者： ZHENG Weishuang, FEI Yingheng, HUANG Yi college of Environmental sciences and Engineering, peking university, beijing 100871, china. [a] college of Environmental sciences Engineering Peking University Beijing 100871 China

Fungi and their symbionts can alleviate heavy metal stress by exuding soluble proteins and enzymes. This study examined the role of soluble protein and acid phosphatase （APase） exuded by Xerocomus chrysenteron, an ectomycorrhizal fungus, and the seedlings of its symbiont, Chinese pine （Pinus tabulaeformis）, under conditions of excessive Cu and Cd. The growth type showed that this poorly studied ectomycorrhizal fungus was capable of tolerating high concentrations of Cu, and may be useful in phytoremediation. X. chrysenteron grew well at 80 mg/L Cu, and the EC50 for Cd was 17.82 mg/L. X. chrysenteron also showed enhanced exudation of soluble protein in both isolated and inoculated cultivations under the influence of Cu and Cd. Soluble protein exudation, however, differed under Cu and Cd stress in isolates. In mediums containing Cu, soluble protein exudation increased with concentration, but in mediums containing Cd the content of soluble protein increased to a comparable level at all concentrations. This study demonstrated that soluble protein was related to heavy metal tolerance, although the different ions played different roles. While APase activity in exudates of fungi and seedlings decreased under Cu and Cd stress in comparison to the control, the APase activity in seedlings was maintained by inoculation. Thus, X. chrysenteron facilitated the ability of plant to maintain a normal nutrient uptake, and therefore to protect it from heavy metal toxicity.

关键词： soluble protein acid phosphatase exudate Cu, Cd Xerocomus chrysenteron

Anti-nociceptive role of neuropeptide Y in the nucleus accumbens in rats with inflammation, an effect modulated by mu- and kappa-opioid receptors

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2006年第2期16卷 133-141页

作者： LI Jinju and YU Longchuan (Laboratory of Neurobiology, college of life sciences, and National Laboratory of Biomembrane and Membrane Biotechnology, peking university, beijing 100871, china) [a]Laboratory of Neurabiology College of life Sciences and National Laboratory of Biomembrane and Membrane Biotechnology Peking University Beijing China

Recent study in our laboratory showed that neuropeptide Y (NPY) plays an antinociceptive role in the nucleus accum-bens (NAc) in intact rats. The present study was performed to further investigate the effect of NPY in nociceptive modulation in the NAc of rats with inflammation, and the possible interaction between NPY and the opioid systems. Experimental inflammation was induced by subcutaneous injection of carrageenan into the left hindpaw of rats. Intra-NAc administration of NPY induced a dose-dependent increase of hindpaw withdrawal latencies (HWLs) to thermal and mechanical stimulations in rats with inflammation. The anti-nociceptive effect of NPY was significantly blocked by subsequent intra-NAc injection of the Y1 receptor antagonist NPY28-36, suggesting an involvement of Y1 receptor in the NPY-induced anti-nociception. Furthermore, intra-NAc administration of the opioid antagonist naloxone significantly antagonized the increased HWLs induced by preceding intra-NAc injection of NPY, suggesting an involvement of the endogenous opioid system in the NPY-induced anti-nociception in the NAc during inflammation. Moreover, the NPY-induced anti-nociception was attenuated by following intra-NAc injection of the μ-opioid antagonist β-funaltrexamine (β-FNA), and κ-opioid antagonist nor-binaltorphimine (nor-BNI), but not by S-opioid antagonist naltrindole, indicating that μ- and K-opioid receptors, not S-opioid receptor, are involved in the NPY-induced anti-nociception in the NAc in rats with inflammation.

关键词： nucleus accumbens, neuropeptide Y, Y1 receptor, carrageenan anti-nociception, μ- and κ-opioid receptors.