1,338 research outputs found

    Activation of the neurokinin-1 receptor by substance P triggers the release of substance P from cultured adult rat dorsal root ganglion neurons

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    <p>Abstract</p> <p>Background</p> <p>Although substance P (SP) is an important primary afferent modulator in nociceptive processes, it is unclear whether SP regulates its own release from primary sensory neurons.</p> <p>Results</p> <p>Using a highly sensitive radioimmunoassay for SP, we have demonstrated that the activation of neurokinin-1 receptor by SP or GR73632 (a potent neurokinin-1 receptor agonist) triggered an increase of SP release from cultured adult rat dorsal root ganglion (DRG) neurons depending on the dose and exposure time within 60 min, and thereafter, the SP release level gradually decreased over 360 min. Accompanying the SP release, a significant reduction in the percentage of neurons expressing neurokinin-1 receptor on their membranes during exposure to SP (200 pg/dish) occurred time dependently (56 Ā± 5% and 32 Ā± 2% at 180 and 360 min, respectively). The GR73632-evoked (10 nM, 60 min) SP release was attenuated by several inhibitors for mitogen-activated protein kinase kinase, p38 mitogen-activated protein (MAP) kinase and cyclooxygenase-2 (COX-2), protein kinase C (PKC), respectively. In contrast, a c-Jun NH<sub>2</sub>-terminal kinase inhibitor increased the GR73632-evoked SP release.</p> <p>Conclusion</p> <p>These results indicate that the neurokinin-1 receptor activation by its agonists regulates the SP release process involving the activation of MAP kinases, PKCs and COX-2 from cultured DRG neurons.</p

    Intrinsic intermediate gap states of TiOā‚‚ materials and their roles in charge carrier kinetics

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    Titanium dioxide (TiO 2 ) is regarded as an important prototype photocatalytic material for several decades. The charge carrier kinetics determines the photocatalytic properties of TiO 2 materials; this is found to be greatly dependent on electronic structures. It has been revealed that the intrinsic intermediate gap states (intrinsic GSs) play a significant role in charge carrier kinetics that drive the photocatalytic processes of TiO 2 materials, which are not well summarized until now. Motivated by this thought, the purpose of this review focuses on physiochemical science of the intrinsic GSs of TiO 2 materials and their important role in charge carrier kinetics. We first give a summary on the chemical resources of the intrinsic GSs in TiO 2 and their physiochemical nature. Their general energy distribution, charge carrier population, and the associated thermodynamic properties are also elaborated from an overall viewpoint. We further carefully summarize and compare the experimental studies on the energy and the density distribution of the intrinsic GSs and discuss the associated chemical resources and charge carrier localizations. Trapping is the dominant function of intrinsic GSs in the charge carrier kinetics of TiO 2 materials. The significant effect of trapping on the transport, recombination, and interfacial transfer of charge carriers are also comprehensive summarized. Furthermore, the effects of charge carrier kinetics on photocatalytic performances are also discussed to some extents. Because of the importance of intrinsic GSs in modulating charge carrier kinetics, it is expected to increase the photocatalytic activity by engineering the intrinsic GSs, not only for TiO 2 materials, but also for the other semiconductor photocatalysts

    Revisiting a kNN-based Image Classification System with High-capacity Storage

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    In existing image classification systems that use deep neural networks, the knowledge needed for image classification is implicitly stored in model parameters. If users want to update this knowledge, then they need to fine-tune the model parameters. Moreover, users cannot verify the validity of inference results or evaluate the contribution of knowledge to the results. In this paper, we investigate a system that stores knowledge for image classification, such as image feature maps, labels, and original images, not in model parameters but in external high-capacity storage. Our system refers to the storage like a database when classifying input images. To increase knowledge, our system updates the database instead of fine-tuning model parameters, which avoids catastrophic forgetting in incremental learning scenarios. We revisit a kNN (k-Nearest Neighbor) classifier and employ it in our system. By analyzing the neighborhood samples referred by the kNN algorithm, we can interpret how knowledge learned in the past is used for inference results. Our system achieves 79.8% top-1 accuracy on the ImageNet dataset without fine-tuning model parameters after pretraining, and 90.8% accuracy on the Split CIFAR-100 dataset in the task incremental learning setting.Comment: 16 pages, 7 figures, 6 table

    Formation of SiC Nanocrystals Aligned at the SiO2ļ¼Si Interface Aiming at Sample Preparation for Scanning Tunneling Luminescence Spectroscopy

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    We investigated the synthesis of SiC nanocrystals (NCs) of several nanometers on a crystalline Si(001) surface, aiming at sample preparation for scanning tunneling luminescence using a novel conductive transparency probe. Two methods for C implantation and CO diffusion to SiO2/Si(001) samples were adopred for the formation of nanocrystalline SiC aligned on the Si(001) surface. The characterization of NCs: crystalline structure, shape, size and areal density, were analyzed by reflection high-energy electron diffraction, scanning probe microscopy and Rutherford backscattering spectroscopy. The C implantation method could not form sufficient NCs on the surface since the diffusion of C to the interface was not adequarely promoted by thermal annealing. On the other hand, almost an ideal structure of SiC NCs of ~10 nm on the Si(001) surface was realized by CO annealing under 0.2 bar at 1100 ā„ƒ for 0.5 h. The size of NCs primarily depends on the annealing time: the annealing conditions should be optimized for further decrement of the NC size.Full-Length PaperBy a grant from Research Institute for Integrated Science, Kanagawa Universit

    MicroRNA, hsa-miR-200c, is an independent prognostic factor in pancreatic cancer and its upregulation inhibits pancreatic cancer invasion but increases cell proliferation

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    <p>Abstract</p> <p>Background</p> <p>Recently, the microRNA-200 family was reported to affect cancer biology by regulating epithelial to mesenchymal transition (EMT). Especially, the expression of <it>miR-200c </it>has been shown to be associated with upregulating the expression of <it>E-cadherin</it>, a gene known to be involved in pancreatic cancer behavior. However, the significance of <it>miR-200c </it>in pancreatic cancer is unknown.</p> <p>Methods</p> <p>In the present study, we investigated the relationship between <it>E-cadherin </it>and <it>miR-200c </it>expression in a panel of 14 pancreatic cancer cell lines and in macro-dissected formalin-fixed paraffin-embedded (FFPE) tissue samples obtained from 99 patients who underwent pancreatectomy for pancreatic cancer. We also investigated the effects of <it>miR-200c </it>on the proliferation and invasion of pancreatic cancer cells.</p> <p>Results</p> <p>We found that patients with high levels of <it>miR-200c </it>expression had significantly better survival rates than those with low levels of <it>miR-200c </it>expression. We also found a remarkably strong correlation between the levels of <it>miR-200c </it>and <it>E-cadherin </it>expression.</p> <p>Conclusions</p> <p>These data indicate that <it>miR-200c </it>may play a role in the pancreatic cancer biology and may be a novel marker for the prognosis of pancreatic cancer.</p

    Crystal structure of mixed fluorites Ca(1-x)Sr(x)F(2) and Sr(1-x)Ba(x)F(2) and luminescence of Eu(2+) in the crystals

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    Within the framework of the virtual crystal method implemented in the shell model and pair potential approximation the crystal structure of mixed fluorites Ca(1-x)Sr(x)F(2) and Sr(1-x)Ba(x)F(2) has been calculated. The impurity center Eu(2+) and the distance Eu(2+)-F in this crystals have been also calculated. The low level position of excited 4f65d configuration of the Eu(2+) ion has been expressed using phenomenological dependence on distance E(2+)-F. The dependences of Stokes shift and Huang-Rhys factor on concentration x have been received for yellow luminescence in Sr(1-x)Ba(x)F(2):Eu(2+). The value x, for which the eg -level of Eu(2+) ion will be in conduction band in Sr(1-x)Ba(x)F(2):Eu(2+) has been calculated.Comment: 8 pages, 3 figures. The manuscript is sent to journal 'Physics of the solid state'. The results will be submitted on inernational conference SCINTMAT'2002 in oral session (june,20-22,2002,Ekaterinburg,Russia). Corresponding author e-mail: [email protected]

    Auto-tracking camera for dry-box laparoscopic training

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    While laparoscopic surgery is less invasive than open surgery and is now common in various medical fields, laparoscopic surgery often requires more time for the operator to achieve mastery. Dry box training is one of the most important methods for developing laparoscopic skill. However, the camera is usually fixed to a particular point, which is different from practical surgery, during which the operational field is constantly adjusted by an assistant. Therefore, we introduced a camera for dry box training that can be moved by surgeons as desired by using computer vision. By detecting the ArUco marker, the camera attached onto the servomotor successfully tracked the forceps automatically. This system could easily be modified and become operable by a foot switch or voice, and collaborations between surgeons and medical engineers are expected

    A Deā€…Novo Designed Metalloenzyme for the Hydration of CO 2

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    Protein design will ultimately allow for the creation of artificial enzymes with novel functions and unprecedented stability. To test our current mastery of natureā€™s approach to catalysis, a Zn II metalloenzyme was prepared using deā€…novo design. Ī± 3 DH 3 folds into a stable singleā€stranded threeā€helix bundle and binds Zn II with high affinity using His 3 O coordination. The resulting metalloenzyme catalyzes the hydration of CO 2 better than any small molecule model of carbonic anhydrase and with an efficiency within 1400ā€fold of the fastest carbonic anhydrase isoform, CAII, and 11ā€fold of CAIII. Chasing down the cheetah : A synthetic metalloenzyme was created that is capable of catalyzing the hydration of carbon dioxide with an efficiency within 1400ā€fold of carbonic anhydraseā€…II, one of the most efficient enzymes known. This designed zinc enzyme performs better than smallā€molecule models of carbonic anhydrase. Picture: Znā€…purple, Nā€…dark blue, Oā€…red, Cā€…cyan.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108029/1/anie_201404925_sm_miscellaneous_information.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/108029/2/7900_ftp.pd
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