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Human sensory and motor systems provide the natural means for the exchange of information between individuals, and, hence, the basis for human civilization. The recent development of brain-computer interfaces (BCI) has provided an important element for the creation of brain-to-brain communication systems, and precise brain stimulation techniques are now available for the realization of non-invasive computer-brain interfaces (CBI). These technologies, BCI and CBI, can be combined to realize the vision of non-invasive, computer-mediated brain-to-brain (B2B) communication between subjects (hyperinteraction). Here we demonstrate the conscious transmission of information between human brains through the intact scalp and without intervention of motor or peripheral sensory systems. Pseudo-random binary streams encoding words were transmitted between the minds of emitter and receiver subjects separated by great distances, representing the realization of the first human brain-to-brain interface. In a series of experiments, we established internet-mediated B2B communication by combining a BCI based on voluntary motor imagery-controlled electroencephalographic (EEG) changes with a CBI inducing the conscious perception of phosphenes (light flashes) through neuronavigated, robotized transcranial magnetic stimulation (TMS), with special care taken to block sensory (tactile, visual or auditory) cues. Our results provide a critical proof-of-principle demonstration for the development of conscious B2B communication technologies. More fully developed, related implementations will open new research venues in cognitive, social and clinical neuroscience and the scientific study of consciousness. We envision that hyperinteraction technologies will eventually have a profound impact on the social structure of our civilization and raise important ethical issues.  相似文献   
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Functional alterations of macrophages in autoimmune MRL-lpr/lpr mice   总被引:6,自引:0,他引:6  
To assess the role of macrophages (MAC) in the pathogenesis of systemic lupus erythematosus, we investigated functional aspects of peritoneal MAC obtained from autoimmune MRL/MpJ-lpr/lpr (MRL-lpr) mice. MRL-lpr and control C3H/HeN MAC were obtained from untreated mice or mice injected i.p. with 1 ml of 10% sterile peptone 3 days before cell harvest. MRL-lpr mice had significantly more peritoneal cells (MAC and lymphocytes) than did control mice. In endotoxin-free conditions, MRL-lpr MAC were similar to C3H/HeN MAC in their baseline, and IFN-gamma and/or LPS enhanced cytolysis of 3T12 fibrosarcoma tumor cells. Compared with C3H/HeN MAC, MRL-lpr MAC had a significant increase in antibody-dependent cellular cytotoxicity activity against sheep erythrocytes. This enhanced activity was not accompanied by a similar increase in adherence and/or phagocytosis of the same targets. Finally, in response to phorbol myristate acetate stimulation, both resident and peptone-induced MAC from MRL-lpr mice produced significantly more hydrogen peroxide than did those from control mice. These results indicate that MAC from MRL-lpr mice display features of selective "activation", and suggest that MAC or their products may play a role in the pathogenesis of inflammatory disorders seen in autoimmune diseases.  相似文献   
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Synthetic peptides corresponding to 57% of the sequence of alpha subunits of acetylcholine receptors from Torpedo californica electric organ and extending from the NH2 to the COOCH terminus have been synthesized. The alpha-bungarotoxin binding site on denatured alpha subunits was mapped within the sequence alpha 185-199 by assaying binding of 125I-alpha-bungarotoxin to slot blots of synthetic peptides. Further studies showed that residues in the sequence alpha 190-194, especially cysteines-alpha 192, 193, were critical for binding alpha-bungarotoxin. Reduction and alkylation studies suggested that these cysteines must be disulfide linked for alpha-bungarotoxin to bind. Binding sites for serum antibodies to native receptors or alpha subunits were mapped by indirect immunoprecipitation of 125I-peptides. Several antigenic sequences were identified, but a synthetic peptide corresponding to the main immunogenic region (which is highly conformation dependent) was not identified.  相似文献   
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An aminopeptidase was purified from cell extracts of Lactococcus lactis subsp. cremoris AM2 by ion-exchange chromatography. After electrophoresis of the purified enzyme in the presence or absence of sodium dodecyl sulfate, one protein band was detected. The enzyme was a 300-kilodalton hexamer composed of identical subunits not linked by disulfide bridges. Activity was optimal at 40 degrees C and pH 7 and was inhibited by classical thiol group inhibitors. The aminopeptidase hydrolyzed naphthylamide-substituted amino acids, as well as dipeptides and tripeptides. Longer protein chains such as the B chain of insulin were hydrolyzed, but at a much slower rate. The Michaelis constant (K(m)) and the maximal rate of hydrolysis (V(max)) were, respectively, 4.5 mM and 3,600 pkat/mg for the substrate l-histidyl-beta-naphthylamide. Amino acid analysis showed that the enzyme contained low levels of hydrophobic residues. The partial N-terminal sequence of the first 19 residues of the mature enzyme was determined. Polyclonal antibodies were obtained from the purified enzyme, and after immunoblotting, there was no cross-reaction between these antibodies and other proteins in the crude extract.  相似文献   
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Green cybrids with a new nucleus-chloroplast combination cannot be selected after protoplast fusion in the intersubfamilial Nicotiana-Solanum combination. As an approach to overcome the supposed plastomegenome incompatibility, a partial plastome transfer by genetic recombination has been considered. After fusions of protoplasts of a light-sensitive Nicotiana tabacum (tobacco) plastome mutant and lethally irradiated protoplasts of wild-type Solanum tuberosum (potato), a single green colony was recovered among 2.5×104 colonies. The regenerated plants had tobacco-like (although abnormal) morphology, but were normally green, and sensitive to tentoxin, demonstrating chloroplast markers of the potato parent. Restriction enzyme analysis of the chloroplast DNA (cpDNA) revealed recombinant, nonparental patterns. A comparison with physical maps of the parental cpDNA demonstrated the presence of a considerable part of the potato plastome flanked by tobacco-specific regions. This potacco plastome proved to be stable in backcross and backfusion experiments, and normally functional in the presence solely of N. tabacum nucleus.  相似文献   
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Summary DNA clones that encode the group-II subunits of soybean glycinin were identified and compared with clones for group-I subunits. The group-I clones hybridize weakly to those from group-II at low stringency, but fail to hybridize with them at moderate or high stringency. The genes for the group-II subunits are contained in 13 and 9 kb EcoRI fragments of genomic DNA in cultivar CX635-1-1-1. These fragments contain genes for subunits A5A4B3 and A3B4, respectively. The larger size of mature group-II subunits compared with group-I subunits is correlated with a larger sized mRNA. However, the gross arrangement of introns and exons within the group-II coding regions appears to be the same as for the genes which encode group-I subunits. Messenger RNA for both groups of glycinin subunits appear in the seed at the same developmental interval, and their appearance lags slightly behind that of mRNAs for the a/a subunits of -conglycinin. These data indicate that the glycinin gene family is more complex than previously thought.Abbreviations bp base pairs - kb kilobase pairs - SDS sodium dodecyl sulfate Cooperative research between USDA/ARS and the Indiana Agric. Expt. Station. This work was supported in part by grants from the USDA Competitive Grants Program and the American Soybean Association Research Foundation. This is Journal Paper No. 10,078 from the Purdue Agricultural Experiment Station  相似文献   
9.
The conformation–biological activity relationships in a series of angiotensin II analogs substituted in position 5 were studied. Results indicated that only analogs with β-branched residue in position 5 possess spectral and biological properties identical to that of parent angiotensin II.  相似文献   
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The budding capacity ofBegonia rex leaf fragments is well known; that of undetached leaves has been shown by us only recently after treating the leaves with 6γγ DMAAP. Benzyladenine is as effective as 6γγ DMAAP in stimulating budding. Lower temperatures (17°, 22–12°, 12°) are also capable of inducing bud formation but only after a small cut has been made in a main vein of the undetached leaf. Root formation can also be provoked on undetached leaves which have a cut in the main leaf vein by higher temperatures (24–22°) or by an IAA treatment. Differences in the first stages of bud formation on leaf fragments and on undetached leaves are observed using histochemical and histoautoradiographic techniques.  相似文献   
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