926 research outputs found

    Poly[[[bis­(acetato-κO)copper(II)]-μ-1,4-diimidazol-1-ylbenzene-κ2 N 3:N 3′] dihydrate]

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    In the title linear coordination polymer, {[Cu(C2H3O2)2(C12H10N4)]·2H2O}n, the CuII atom is coordinated by two N atoms from two different symmetry-related 1,4-diimidazol-1-ylbenzene (dib) ligands and two carboxyl­ate O atoms from two acetate ligands in a square-planar geometry. The Cu atoms are linked by the dib ligands, forming an extended chain. These chains are linked by O—H⋯O hydrogen bonds into a three-dimensional supra­molecular network. The CuII atom lies on a center of inversion

    MUSE: An Efficient and Accurate Verifiable Privacy-Preserving Multikeyword Text Search over Encrypted Cloud Data

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    With the development of cloud computing, services outsourcing in clouds has become a popular business model. However, due to the fact that data storage and computing are completely outsourced to the cloud service provider, sensitive data of data owners is exposed, which could bring serious privacy disclosure. In addition, some unexpected events, such as software bugs and hardware failure, could cause incomplete or incorrect results returned from clouds. In this paper, we propose an efficient and accurate verifiable privacy-preserving multikeyword text search over encrypted cloud data based on hierarchical agglomerative clustering, which is named MUSE. In order to improve the efficiency of text searching, we proposed a novel index structure, HAC-tree, which is based on a hierarchical agglomerative clustering method and tends to gather the high-relevance documents in clusters. Based on the HAC-tree, a noncandidate pruning depth-first search algorithm is proposed, which can filter the unqualified subtrees and thus accelerate the search process. The secure inner product algorithm is used to encrypted the HAC-tree index and the query vector. Meanwhile, a completeness verification algorithm is given to verify search results. Experiment results demonstrate that the proposed method outperforms the existing works, DMRS and MRSE-HCI, in efficiency and accuracy, respectively

    Origin of the Oligocene Tuolangla porphyry-skarn Cu-W-Mo deposit in Lhasa terrane, southern Tibet

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    Although some porphyry-skarn deposits occur in post-collisional extensional settings, the post-collisional deposits remain poorly understood. Here the authors describe the igneous geology, and mineralization history of Tuolangla, a newly-discovered porphyry-skarn Cu-W-Mo deposit in southern Tibet that belongs to the post-collisional class. The deposit is associated with Lower Cretaceous Bima Formation. It was intruded by granodiorite porphyry intrusions at about 23.1 Ma. Field investigation indicated that mineralization is spatially and temporally associated with granodiorite porphyry. Molybdenite yielded a Re-Os weighted mean age of 23.5 +/- 0.3 Ma and is considered to represent the age of skarn mineralization at the deposit. The delta S-34 values of sulfides, concentrated in a range between 0.6 parts per thousand to 3.4 parts per thousand, show that the sulfur has a homogeneous source with characteristics of magmatic sulfur. The Pb isotopic compositions of sulfides indicate that ore-forming metal materials were derived from the mantle and ancient crust. The granodiorite porphyry displays high SiO2 (68.78%-69.75%) and K2O (3.40%-3.56%) contents, and relatively lower Cr (2.4x10(-6) -4.09x10(-6) ), Ni (2.79x10(-6)-3.58x10(-6)) contents, and positive epsilon(Hf)(t) values (7.7-12.9) indicating that the mineralization porphyry was derived from the partial melting of juvenile lower crust. The Tuolangla deposit is located in the central part of Zedang terrane. This terrane was once considered an ancient terrane. This terrane is in tectonic contact with Cretaceous ophiolitic rocks to its south and Mesozoic continental margin arc volcanics and intrusions of the Gangdese batholith of the Lhasa terrane to its north. Thus, the authors proposed that the Oligocene porphyry skarn Cu-W-Mo mineralization is probably associated with the Zedang terrane. This finding may clarify why the Oligocene (about 23 Ma) deposits are found only in the Zedang area and why mineralization types of the Oligocene mineralization are considerably different from those of the Miocene (17-14 Ma) mineralization. (C) 2020 China Geology Editorial Office

    Microvascular Endothelial Cells-Derived Microvesicles Imply in Ischemic Stroke by Modulating Astrocyte and Blood Brain Barrier Function and Cerebral Blood Flow

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    Background Endothelial cell (EC) released microvesicles (EMVs) can affect various target cells by transferring carried genetic information. Astrocytes are the main components of the blood brain barrier (BBB) structure in the brain and participate in regulating BBB integrity and blood flow. The interactions between ECs and astrocytes are essential for BBB integrity in homeostasis and pathological conditions. Here, we studied the effects of human brain microvascular ECs released EMVs on astrocyte functions. Additionally, we investigated the effects of EMVs treated astrocytes on regulating BBB function and cerebral ischemic damage. Results EMVs prepared from ECs cultured in normal condition (n-EMVs) or oxygen and glucose deprivation (OGD-EMVs) condition had diverse effects on astrocytes. The n-EMVs promoted, while the OGD-EMVs inhibited the proliferation of astrocytes via regulating PI3K/Akt pathway. Glial fibrillary acidic protein (GFAP) expression (marker of astrocyte activation) was up-regulated by n-EMVs, while down-regulated by OGD-EMVs. Meanwhile, n-EMVs inhibited but OGD-EMVs promoted the apoptosis of astrocytes accompanied by up/down-regulating the expression of Caspase-9 and Bcl-2. In the BBB model of ECs-astrocytes co-culture, the n-EMVs, conversely to OGD-EMVs, decreased the permeability of BBB accompanied with up-regulation of zonula occudens-1(ZO-1) and Claudin-5. In a transient cerebral ischemia mouse model, n-EMVs ameliorated, while OGD-EMVs aggravated, BBB disruption, local cerebral blood flow (CBF) reduction, infarct volume and neurological deficit score. Conclusions Our data suggest that EMVs diversely modulate astrocyte functions, BBB integrity and CBF, and could serve as a novel therapeutic target for ischemic stroke

    Endoscopic Ultrasonography in the Diagnosis and Treatment Strategy Choice of Esophageal Leiomyoma

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    OBJECTIVES: Esophageal leiomyoma is the most common benign tumor of the esophagus, and it originates from mesenchymal tissue. This study analyzed the clinicopathological characteristics of esophageal leiomyoma and aimed to evaluate the role of endoscopic ultrasonography in the diagnosis and treatment selection for these lesions. METHODS: Two hundred and twenty-five patients who had suspected esophageal leiomyomas in endoscopic ultrasonography were enrolled at the Endoscopy Center of The First Affiliated Hospital, Zhejiang University from January 1st, 2009 to May 31th, 2015. The main outcomes included the demographic and morphological characteristics, symptoms, comparisons of diagnosis and treatment methods, adverse events, and prognosis. RESULTS: One hundred and sixty-seven patients were diagnosed as having an esophageal leiomyoma by pathological examination. The mean patient age was 50.57±9.983 years. In total, 62.9% of the lesions originated from the muscularis mucosa, and the others originated from the muscularis propria. The median distance to the incisors was 30±12 cm. The median diameter was 0.72±0.99 cm. As determined by endoscopic ultrasonography, most existing leiomyomas were homogeneous, endophytic, and spherical. The leiomyomas from the muscularis mucosa were smaller than those from the muscularis propria and much closer to the incisors (
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