1,262 research outputs found

    Combining interscalene brachial plexus block with intravenous-inhalation combined anesthesia for upper extremity fractures surgery: A randomized controlled trial

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    AbstractBackground: A parallel-group randomized controlled trial (RCT) was conducted to evaluate the effect of combining the interscalene brachial plexus block (IBPB) with Intravenous–inhalation combined anesthesia to isolated Intravenous–inhalation anesthesia in the upper extremity fractures surgery of elderly patients. Methods: One hundred elderly patients who underwent upper extremity surgery were randomly assigned to received isolated Intravenous–inhalation combined anesthesia (group CI, n = 50) and IBPB associated with Intravenous–inhalation combined anesthesia (group NB, n = 50). Associated side effects, recovery time after operation, as well as the dose of intraoperative vasoactive agents and auxiliary drugs were noted. Results: The two groups were not significantly different in gender (P = 0.539), ages (P = 0.683) and weight (P = 0.212). Five patients (10%) in the group NB and 17 patients (34%) in the group CI suffered from preoperative hypotension (P = 0.004). Besides, lower incidence of other adverse effects such as mental stress, incision pain and hypertension were also found in the group NB; however, the differences were not statistically significant (P > 0.05). The consumption of general anesthetics in the group NB was significantly less than that of the group CI (propofol, P = 0.004; lsoflurane, P < 0.001), and the recovery time of the group NB was significantly shorter than that of the group CI (P = 0.020). Conclusion: Combining IBPB with Intravenous–inhalation combined anesthesia in elderly patients hold a greater potential for upper extremity fractures surgery due to its improved clinical effectiveness and fewer side effects

    2-Amino-4-(4-fluoro­phen­yl)-6-(naphthalen-1-yl)pyridine-3-carbonitrile

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    The title compound, C22H14FN3, was prepared by a one-pot condensation using malononitrile, an aromatic aldehyde, a methyl ketone and ammonium acetate as reacta­nts under microwave irradiation. The pyridine ring is twisted with respect to the benzene ring and the naphthalene ring system, making dihedral angles of 41.9 (1) and 45.2 (1)°, respectively. In the crystal, mol­ecules are connected via inter­molecular N—H⋯N and C—H⋯F hydrogen bonds, forming a three-dimensional network

    tert-Butyl N-{4-methyl-3-[4-(3-pyrid­yl)pyrimidin-2-yl­oxy]phen­yl}carbamate

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    In the mol­ecule of the title compound, C21H22N4O3, the pyrimidine ring is oriented at dihedral angles of 0.51 (3) and 50.76 (3)° to the pyridine and benzene rings, respectively. In the crystal structure, inter­molecular N—H⋯N hydrogen bonds link the mol­ecules into centrosymmetric dimers, forming R 2 2(24) ring motifs; the dimers are linked by inter­molecular C—H⋯O hydrogen bonds into a two-dimensional network. π–π contacts between the benzene rings and between the pyrimidine and pyridine rings [centroid–centroid distances = 3.891 (1) and 3.646 (1) Å, respectively] may further stabilize the structure. Two weak C—H⋯π inter­actions are also present

    Efficient Secure Storage with Version Control and Key Rotation

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    Periodic key rotation is a widely used technique to enhance key compromise resilience. Updatable encryption (UE) schemes provide an efficient approach to key rotation, ensuring post-compromise security for both confidentiality and integrity. However, these UE techniques cannot be directly applied to frequently updated databases due to the risk of a malicious server inducing the client to accept an outdated version of a file instead of the latest one. To address this issue, we propose a scheme called Updatable Secure Storage (USS), which provides a secure and key updatable solution for dynamic databases. USS ensures both data confidentiality and integrity, even in the presence of key compromises. By using efficient key rotation and file update procedures, the communication costs of these operations are independent of the size of the database. This makes USS particularly well-suited for managing large and frequently updated databases with secure version control. Unlike existing UE schemes, the integrity provided by USS holds even when the server learns the current secret key and intentionally violates the key update protocol

    Re–Os isotope geochronology of the Shangbao pyrite–flourite deposit in southeastern Hunan, South China: Evidence for multiple mineralization events and the role of crust–mantle interaction in polymetallic deposits

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    In South China, both crustal reworking and crust–mantle interaction were important geological processes during the Paleozoic and Mesozoic eras. However, the relationships between these two processes and metal mineralization are still unknown. Here we report rhenium and osmium isotopic data for pyrite grains from a pyrite deposit associated with a granite intrusion in the Shangbao area, southeastern Hunan Province (South China). Two pyrite samples, both containing many euhedral pyrite grains, were collected from the same locality, but the samples yield distinct ages. Six euhedral pyrite grains from one sample yield an isochronal age of 279 ± 12 Ma, with an initial 187Os/188Os ratio of 0.39 ± 0.71, and Re and Os concentrations of 0.12–63.5 ppb and 2.14–185 ppt, respectively. This Early Permian age is in good agreement with the age of the strata that host the pyrite deposit. Five euhedral pyrite grains from the other sample yield an isochronal age of 75.2 ± 4.3 Ma, with an initial 187Os/188Os ratio of 0.141 ± 0.030 and Re and Os concentrations of 0.15–0.43 ppb and 1.0–39.9 ppt, respectively. If one pyrite grain with the highest 187Re/188Os and 187Os/188Os ratios is excluded, other four pyrite grains give an isochronal age of 85 ± 13 Ma. The Late Cretaceous age (75–85 Ma) is consistent with the zircon U–Pb age of the Shangbao granites (80.1 ± 0.3 Ma) to within uncertainties. Considering also the relatively lower radiogenic initial 187Os/188Os ratio of this sample, we suggest that the later stage pyrite ore was probably formed through crystallization from the magmatic hydrothermal fluids. Combined with other geological and associated magmatic data, we propose a skarn-related fluid–ore interaction process to explain the second stage of metallogenesis in the Shangbao pyrite deposit. The Early Permian pyrite ore was deposited in a brine basin with evaporites during the Early Permian. Later magmatic hydrothermal fluids originating from the Shangbao granites, which included mantle components, interacted with the strata and the Early Permian pyrite ore during the Late Cretaceous and precipitated a later stage pyrite ore. During the Late Mesozoic, the roll-back of subducted Paleo-Pacific plate caused lithospheric extension in South China, triggering the upwelling and partial melting of the asthenosphere. The resulting underplating of mantle-derived magmas provided a vast amount of heat and materials for the formation of the granites and polymetallic deposits in South China. Given that the multiple mineralization events were spatially and temporally associated with the Paleozoic–Mesozoic magmatism, the Re–Os isotopic dating of euhedral pyrite grains has been shown to be a viable method for unveiling the evolutionary history of ore-deposits. Skarn development caused by granite and mafic dike emplacement resulting from crust–mantle interaction explains the occurrence of two mineralization episodes at the same locality

    Speeding Dumbo: Pushing Asynchronous BFT Closer to Practice

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    Asynchronous BFT consensus can implement robust mission-critical decentralized services in the unstable or even adversarial wide-area network without relying on any form of timing assumption. Starting from the work of HoneyBadgerBFT (CCS 2016), several studies tried to push asynchronous BFT towards practice. In particular, in a recent work of Dumbo (CCS 2020), they redesigned the protocol backbone and used one multi-valued validated Byzantine agreement (MVBA) to replace nn concurrent asynchronous binary agreement (ABA) protocols and dramatically improved the performance. Despite those efforts, asynchronous BFT protocols remain to be slow, and in particular, the latency is still quite large. There are two reasons contributing to the inferior performance: (1) the reliable broadcast (RBC) protocols still incur substantial costs; (2) the MVBA protocols are quite complicated and heavy, and all existing constructions need dozens of rounds and take the majority of he overall latency. We first present a new construction of asynchronous BFT that replaces RBC instance with a cheaper broadcast component. It not only reduces the O(n3)O(n^3) message complexity incurred by nn RBCs to O(n2)O(n^2), but also saves up to 67% communications (in the presence of a fair network scheduler). Moreover, our technical core is a new MVBA protocol, Speeding MVBA, which is concretely more efficient than all existing MVBAs. It requires only 6 rounds in the best case and expected 12 rounds in the worst case (by contrast, several dozens of rounds in the MVBA from Cachin et al. [12] and the recent Dumbo-MVBA [32], and around 20 rounds in the MVBA from Abraham et al. [4]). Our new technique of the construction might be of independent interests. We implemented Speeding Dumbo and did extensive tests among up to 150 EC2 t2.medium instances evenly allocated in 15 AWS regions across the globe. The experimental results show that Speeding Dumbo reduces the latency to about a half of Dumbo\u27s, and also doubles the throughput of Dumbo, through all system scales from 4 nodes to 150 nodes. We also did tests to benchmark individual components such as the broadcasts and the MVBA protocols, which may be of interests for future improvements

    Refined mapping of loss of heterozygosity in Chinese sporadic gastric carcinoma

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    The aim of this study is to explore precise deleted regions where the candidate tumor suppressor genes might be located in Chinese sporadic gastric carcinoma. By searching in Genothon, NCBI and GDB databases, 145 polymorphic microsatellite markers were chosen, at a mean density of approximately one marker every 2 - 4 cM, covering 15 chromosomes. These polymorphic microsatellite markers in gastric carcinoma and adjacent tissue were analyzed via PCR. PCR products were submitted to electrophoresis on an ABI 3730 DNA sequencer. Genemapper3.2 software was used for LOH (Loss of Heterozygosity) scanning and analysis. Comparison between LOH frequency and clinicopathological factors was performed by Fisher’s exact test. 26 refined regions were mapped as candidate regions for TSGs (Tumor suppression genes) in Chinese sporadic gastric cancer. Associations between LOH and clinical information indicated that 6 loci was associated with pTNM stage, 5 with Lauren's type, 4 with lymph nodes metastasis and another 2 with distant metastasis. Through refined deletion mapping, 26 candidate regions, where TSGs may be located, were found and 17 loci were proposed to be used as clinical markers in Chinese sporadic gastric cancer.Keywords: Gastric carcinoma, refined mapping, loss of heterozygosity (LOH), tumor suppressor genes (TSGs), tumor markersAfrican Journal of Biotechnology Vol. 9(35), pp. 5754-5761, 30 August, 201
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