129 research outputs found

    Efficient Strong Privacy-Preserving Conjunctive Keyword Search Over Encrypted Cloud Data

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    Searchable symmetric encryption (SSE) supports keyword search over outsourced symmetrically encrypted data. Dynamic searchable symmetric encryption (DSSE), a variant of SSE, further enables data updating. Most DSSE works with conjunctive keyword search primarily consider forward and backward privacy. Ideally, the server should only learn the result sets involving all keywords in the conjunction. However, existing schemes suffer from keyword pair result pattern (KPRP) leakage, revealing the partial result sets containing two of query keywords. We propose the first DSSE scheme to address aforementioned concerns that achieves strong privacy-preserving conjunctive keyword search. Specifically, our scheme can maintain forward and backward privacy and eliminate KPRP leakage, offering a higher level of security. The search complexity scales with the number of documents stored in the database in several existing schemes. However, the complexity of our scheme scales with the update frequency of the least frequent keyword in the conjunction, which is much smaller than the size of the entire database. Besides, we devise a least frequent keyword acquisition protocol to reduce frequent interactions between clients. Finally, we analyze the security of our scheme and evaluate its performance theoretically and experimentally. The results show that our scheme has strong privacy preservation and efficiency

    Gallic acid-grafted chitosan antibacterial hydrogel incorporated with polydopamine-modified hydroxyapatite for enhancing bone healing

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    An open critical-size bone defect is a major medical problem because of the difficulty in self-healing, leading to an increased risk of bacterial infection owing to wound exposure, resulting in treatment failure. Herein, a composite hydrogel was synthesized by chitosan, gallic acid, and hyaluronic acid, termed “CGH.” Hydroxyapatite was modified with polydopamine (PDA@HAP) and introduced to CGH to obtain a mussel-inspired mineralized hydrogel (CGH/PDA@HAP). The CGH/PDA@HAP hydrogel exhibited excellent mechanical performances, including self-healing and injectable properties. Owing to its three-dimensional porous structure and polydopamine modifications, the cellular affinity of the hydrogel was enhanced. When adding PDA@HAP into CGH, Ca2+ and PO43- could release and then promoted differentiation of BMSCs into osteoblasts. Without any osteogenic agent or stem cells, the area of new bone at the site of defect was enhanced and the newly formed bone had a dense trabecular structure after implanting of the CGH/PDA@HAP hydrogel for 4 and 8 weeks. Moreover, the growth of Staphylococcus aureus and Escherichia coli was effectively inhibited through the grafting of gallic acid onto chitosan. Above, this study provides a reasonable alternative strategy to manage open bone defects

    THE PREVENTIVE EFFECT AND ENHANCE IMMUNITY FUNCTION OF BU-ZHONG-YI-QIWAN ON S180 TUMOR MICE.

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    Background: To evaluate the preventive effect and enhance immunity functions of Bu-zhong-yi-qi wan in vivo. Materials and Methods: S180 tumor mice model was established by subcutaneous injection a dose of 0.2 ml (1×107/ml) at the right oxter. The inhibitory rates, spleen indexes and thymus indexes were calculated. Splenic lymphocyte proliferative activity assay and phagocytosis activity of peritoneal macrophages were done. Interferon (IFN-γ), interleukin (IL-2) and tumor necrotic factor (TNF-α) in serum were detected. Results: In the S180 tumor-bearing mice, Bu-zhong-yi-qi wan with medium-dose (975 mg/kg, 100 mg/l) had potent preventive effect and anti-tumor effect, macrophage phagocytosis and Con A-stimulated splenocyte proliferation were increased as compared with model control treatment. Bu-zhong-yi-qi wan could take part in the immune response by promoting the proliferation and differentiation of Tcells, increasing the activity of the macrophages, inducing the generation of cell factor IL-2, TNF-α, IFN-γ. Conclusion: It proved that Bu-zhong-yi-qi wan of medium-dose had great preventive effect and could enhance immunity function

    Upregulation of AT1 Receptor Mediates a Pressor Effect Through ROS-SAPK/JNK Signaling in Glutamatergic Neurons of Rostral Ventrolateral Medulla in Rats With Stress-Induced Hypertension

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    The present study examined whether angiotensin II (Ang II) mediates the pressor effect through nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-derived reactive oxygen species (ROS)-mitogen-activated protein kinase (MAPK) signaling in the glutamatergic neurons of the rostral ventrolateral medulla (RVLM) in stress-induced hypertensive rats (SIHR). The SIHR model was established using electric foot-shocks combined with noises for 15 days. We observed that Ang II type 1 receptor (AT1R) and the glutamatergic neurons co-localized in the RVLM of SIHR. Furthermore, glutamate levels in the intermediolateral column of the spinal cord were higher in SIHR than in controls. Microinjection of Ang II into the RVLM of SIHR activated stress-activated protein kinase/Jun N-terminal kinase (SAPK/JNK), extracellular signal-regulated protein kinase (ERK) 1/2, and p38MAPK. Compared with controls, the activation of SAPK/JNK, ERK1/2, p38MAPK, and ROS in the RVLM were higher in SIHR, an effect that was blocked by an NADPH oxidase inhibitor (apocynin) and an AT1R antagonist (candesartan). RVLM microinjection of apocynin or a SAPK/JNK inhibitor (SP600125), but not an ERK1/2 inhibitor (U0126) or a p38MAPK inhibitor (SB203580), decreased AT1R mRNA and mean arterial blood pressure (MABP) in SIHR. The increase of AT1R protein expression and MABP was inhibited by intracerebroventricular infusion (ICV), for 14 days, of SP600125, but not U0126 or SB203580 in SIHR. We conclude that Ang II modulates the pressor effect through AT1R-dependent ROS-SAPK/JNK signaling in glutamatergic neurons in the RVLM of SIHR

    A Multi-Center Study to Evaluate the Performance of Phage Amplified Biologically Assay for Detecting TB in Sputum in the Pulmonary TB Patients

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    Objective: To evaluate the performance of phage amplified biologically assay (PhaB) for detecting tuberculosis (TB) in sputum in the pulmonary tuberculosis (PTB) patients. Methods: Shanghai Tuberculosis Key Laboratory of Shanghai Pulmonary Hospital participated in the project in collaboration with the laboratories of six hospitals and a total of 1660 eligible participants (1351 PTB patients and 309 non-TB patients) were included in the study. The sputum samples from the participants were detected by smear microscopy, PhaB, and Löwenstein-Jensen (L-J) culture method, respectively. Results: The overall sensitivity of PhaB were higher than that of L-J culture and smear microscopy (p,0.05). The sensitivity of PhaB for detecting smear-negative specimens was obviously higher than that of L-J culture (p,0.05). Compared with L-J culture, the overall sensitivity, specificity, PPV, NPV, ACC and Kappa value of PhaB were 98.4 (95 % Cl: 96.9–99.3), 71.6 (95% Cl: 68.4–74.6), 67.7, 98.7, 81.7 % and 0.643, respectively. The detection median time of PhaB only needed 48 hours, which was significantly less than that (31 days) of L-J culture method. Conclusion: PhaB method is a rapid and sensitive method for detecting TB in sputum in PTB patients; especially for th

    Evaluation of a Novel Biphasic Culture Medium for Recovery of Mycobacteria: A Multi-Center Study

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    on L-J slants. Automated liquid culture systems are expensive. A low-cost culturing medium capable of rapidly indicating the presence of mycobacteria is needed. The aim of this study was to develop and evaluate a novel biphasic culture medium for the recovery of mycobacteria from clinical sputum specimens from suspected pulmonary tuberculosis patients.<0.001).

    Effects of Corn Varieties and Moisture Content on Mechanical Properties of Corn

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    The purpose of this study is to explore how corn varieties and moisture content affect the mechanical properties of corn with high moisture content (26.0~36.4%). The mechanical properties of corn that affect corn threshing quality are determined by establishing the contact mechanical model of the threshing elements and corn kernels. These mechanical properties of corn include the size characteristics of corn (corn ear weight and corn kernel triaxial size) in addition to the mechanical characteristics of corn (corn elastic modulus, corn kernel breaking force, and corn stalk breaking force). The effects of corn varieties and moisture content on the mechanical properties of corn were tested. The results showed that the corn varieties and moisture content had significant effects on the mechanical properties of corn. Among them, the different levels of moisture content levels have significant differences in the mechanical properties of corn, while corn varieties have different significant differences in the mechanical properties of corn. The ear weight, corn kernel triaxial size, and the axial and radial breaking force of corn pedicels all increased significantly as the moisture content increased. Corn’s elastic modulus, kernel breaking force, and the normal breaking force of corn pedicels all decreased significantly as moisture content increased. The breaking force of corn kernels at different positions is in the order of ventral, lateral, and top surface, and the breaking force of corn pedicels in different directions is in the order of normal, axial, and radial. When the moisture content is between 26.0% and 36.4%, the maximum breaking force of a corn kernel is 401.62 N, and the minimum is 35.47 N. The maximum breaking force of corn pedicels is 32.72 N, and the minimum is 5.37 N. Understanding the influences of these relationships is very important for applications related to the threshing process, such as selecting the threshing mode, designing the threshing mechanism, and setting the threshing parameters
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