Cytomegalovirus recruitment of cellular kinases to dissolve the nuclear lamina     

Muranyi W  Haas J  Wagner M  Krohne G  Koszinowski UH 《Science (New York, N.Y.)》2002,297(5582):854-857

The passage of large-sized herpesviral capsids through the nuclear lamina and the inner nuclear membrane to leave the nucleus requires a dissolution of the nuclear lamina. Here, we report on the functions of M50/p35, a beta-herpesviral protein of murine cytomegalovirus. M50/p35 inserts into the inner nuclear membrane and is aggregated by a second viral protein, M53/p38, to form the capsid docking site. M50/p35 recruits the cellular protein kinase C for phosphorylation and dissolution of the nuclear lamina, suggesting that herpesviruses target a critical element of nuclear architecture.  相似文献   

Oxygen Transport     

Markus G 《Science (New York, N.Y.)》1960,132(3419):95-96

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Large magnetic anisotropy of a single atomic spin embedded in a surface molecular network     

Hirjibehedin CF  Lin CY  Otte AF  Ternes M  Lutz CP  Jones BA  Heinrich AJ 《Science (New York, N.Y.)》2007,317(5842):1199-1203

Magnetic anisotropy allows magnets to maintain their direction of magnetization over time. Using a scanning tunneling microscope to observe spin excitations, we determined the orientation and strength of the anisotropies of individual iron and manganese atoms on a thin layer of copper nitride. The relative intensities of the inelastic tunneling processes are consistent with dipolar interactions, as seen for inelastic neutron scattering. First-principles calculations indicate that the magnetic atoms become incorporated into a polar covalent surface molecular network in the copper nitride. These structures, which provide atom-by-atom accessibility via local probes, have the potential for engineering anisotropies large enough to produce stable magnetization at low temperatures for a single atomic spin.  相似文献   

A selective activity-dependent requirement for dynamin 1 in synaptic vesicle endocytosis     

Ferguson SM  Brasnjo G  Hayashi M  Wölfel M  Collesi C  Giovedi S  Raimondi A  Gong LW  Ariel P  Paradise S  O'toole E  Flavell R  Cremona O  Miesenböck G  Ryan TA  De Camilli P 《Science (New York, N.Y.)》2007,316(5824):570-574

Dynamin 1 is a neuron-specific guanosine triphosphatase thought to be critically required for the fission reaction of synaptic vesicle endocytosis. Unexpectedly, mice lacking dynamin 1 were able to form functional synapses, even though their postnatal viability was limited. However, during spontaneous network activity, branched, tubular plasma membrane invaginations accumulated, capped by clathrin-coated pits, in synapses of dynamin 1-knockout mice. Synaptic vesicle endocytosis was severely impaired during strong exogenous stimulation but resumed efficiently when the stimulus was terminated. Thus, dynamin 1-independent mechanisms can support limited synaptic vesicle endocytosis, but dynamin 1 is needed during high levels of neuronal activity.  相似文献   

Tracing the origin and fate of NOx in the Arctic atmosphere using stable isotopes in nitrate     

Morin S  Savarino J  Frey MM  Yan N  Bekki S  Bottenheim JW  Martins JM 《Science (New York, N.Y.)》2008,322(5902):730-732

Atmospheric nitrogen oxides (NOx =NO+ NO2) play a pivotal role in the cycling of reactive nitrogen (ultimately deposited as nitrate) and the oxidative capacity of the atmosphere. Combined measurements of nitrogen and oxygen stable isotope ratios of nitrate collected in the Arctic atmosphere were used to infer the origin and fate of NOx and nitrate on a seasonal basis. In spring, photochemically driven emissions of reactive nitrogen from the snowpack into the atmosphere make local oxidation of NOx by bromine oxide the major contributor to the nitrate budget. The comprehensive isotopic composition of nitrate provides strong constraints on the relative importance of the key atmospheric oxidants in the present atmosphere, with the potential for extension into the past using ice cores.  相似文献   

Quantum spin hall insulator state in HgTe quantum wells   总被引：1，自引：0，他引：1  

König M  Wiedmann S  Brüne C  Roth A  Buhmann H  Molenkamp LW  Qi XL  Zhang SC 《Science (New York, N.Y.)》2007,318(5851):766-770

Recent theory predicted that the quantum spin Hall effect, a fundamentally new quantum state of matter that exists at zero external magnetic field, may be realized in HgTe/(Hg,Cd)Te quantum wells. We fabricated such sample structures with low density and high mobility in which we could tune, through an external gate voltage, the carrier conduction from n-type to p-type, passing through an insulating regime. For thin quantum wells with well width d < 6.3 nanometers, the insulating regime showed the conventional behavior of vanishingly small conductance at low temperature. However, for thicker quantum wells (d > 6.3 nanometers), the nominally insulating regime showed a plateau of residual conductance close to 2e(2)/h, where e is the electron charge and h is Planck's constant. The residual conductance was independent of the sample width, indicating that it is caused by edge states. Furthermore, the residual conductance was destroyed by a small external magnetic field. The quantum phase transition at the critical thickness, d = 6.3 nanometers, was also independently determined from the magnetic field-induced insulator-to-metal transition. These observations provide experimental evidence of the quantum spin Hall effect.  相似文献   

Post-mortem findings in 54 cases of anesthetic associated death in cats from two spay-neuter programs in New York State     

Gerdin JA  Slater MR  Makolinski KV  Looney AL  Appel LD  Martin NM  McDonough SP 《Journal of Feline Medicine and Surgery》2011,13(12):959-966

Anesthetic-associated death (AAD) in cats is infrequent, but occurs far more frequently than in people. Post-mortem investigations of AAD in cats are uncommon, and results only sporadically published. Here we report the findings in 54 cases of AAD in cats. Significant gross and/or microscopic pre-existing disease, including pulmonary, cardiac, and systemic disease, was detected in 33% of cases. Pulmonary disease was most frequently diagnosed (24% of cases), and included cases of Aelurostrongylus abstrusus infection (9% of cases). Heart disease, including two cases of hypertrophic cardiomyopathy, was less frequent (11% of cases). Four percent died from surgical complications. No?significant gross or microscopic disease was detected in 63% of cases. Additional studies are needed to determine if these findings are representative of AAD in cats in other geographic areas or with access to veterinary care. This study demonstrates that post-mortem investigation of AADs is an important and worthwhile endeavor.  相似文献   

The effects of two analgesic regimes on behavior after abdominal surgery in Steller sea lions     

Walker KA  Horning M  Mellish JA  Weary DM 《Veterinary journal (London, England : 1997)》2011,190(1):160-164

This study examined the effects of two non-steroidal anti-inflammatory drug (NSAID) treatment protocols on the behavioral responses of juvenile Steller sea lions after abdominal surgery. Sea lions were randomly assigned to one of two treatments designed to control post-operative pain. The flunixin group (n=6) received flunixin meglumine (1mg/kg) administered as a single intramuscular (IM) injection before extubation from surgery. The carprofen group (n=5) received carprofen (4.4 mg/kg) as an IM injection before extubation, then orally at 24, 48 and 72 h after surgery. Seven behaviors related to post-operative pain were monitored by observers, blinded to treatment, for a total of 10 days (3 days pre-, day of surgery, and 6 days post-surgery). All seven behaviors changed after surgery regardless of NSAID treatment, two of which returned to baseline within 6 days of surgery. Only one behavior was mildly affected by analgesic treatment: sea lions in the carprofen group tended to spend less time lying down in Days 1-3 following surgery (i.e., the days which they received oral carprofen). These results suggested that neither treatment, at the dose administered, was effective in controlling pain in the days following this surgery.  相似文献   

Different sources of heavy metals and their long-term effects on soil microbial properties   总被引：9，自引：3，他引：9  

Krishan Chander  Jens Dyckmans  Rainer Joergensen  Brunk Meyer  Markus Raubuch 《Biology and Fertility of Soils》2001,34(4):241-247

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An Andosol from Eastern Saxony,Germany     

Markus Kleber  Sabine Zikeli  Michael Kastler  Reinhold Jahn 《植物养料与土壤学杂志》2003,166(4):533-542

We tested whether a ‘Lockerbraunerde’ from the heights of the Zittauer Gebirge in Eastern Saxony exhibited andic properties and classified it according to the rules of the World Reference Base for Soil Resources (WRB, 1998). To achieve this, we characterized a selected soil by means of routine soil analysis; selective dissolution procedures; X‐ray diffraction (XRD); X‐ray fluorescence (XRF), and Transmission Electron Microscopy (TEM). We used field criteria (Thixotropy; NaF‐field test) to obtain a map of the spatial distribution of soils with potential andic properties. We found that the soil fulfilled all requirements to be classified as an Andosol. The composition of the colloidal phases was exactly intermediate between sil‐andic and alu‐andic. At the same time, the soil had a spodic horizon [determined through the depth function of the Al_o+½Fe_o criterion]. As there was no indication of vertical translocation of metal‐organic complexes, but sufficient evidence to suggest the downward movement of mobile Al/Si‐phases, we maintain to classify the soil as an Endoskeleti‐Umbric Andosol and propose the existence of a pedogenetic pathway intermediate between Podsolisation and Andosolization. We conclude that the spodic horizon in the WRB is not well defined because of the dominance of the Al_o+½Fe_o criterion over morphological evidence. We further suggest the German soil taxonomy to be modified to better represent soils containing short range order minerals.  相似文献