195 research outputs found
Highly anisotropic magnetic domain wall behavior in-plane magnetic films
We have studied nucleation of magnetic domains and propagation of magnetic
domain walls (DWs) induced by pulsed magnetic field in a ferromagnetic film
with in-plane uniaxial anisotropy. Different from what have been seen up to now
in out-of-plane anisotropy films, the nucleated domains have a rectangular
shape in which a pair of the opposite sides are perfectly linear DWs, while the
other pair present zigzags. This can be explained by magnetostatic
optimization, knowing that the pulse field is applied parallel to the easy
magnetization axis. The field induced propagation of these two DW types are
very different. The linear ones follow a creep law identical to what is usually
observed in out-of-plane films, when the velocity of zigzag DWs depends
linearly on the applied field amplitude down to very low field. This most
unusual feature can be explained by the shape of the DW, which makes it
possible to go round the pinning defects. Thanks to that, it seems that
propagation of zigzag walls agrees with the 1D model, and these results provide
a first experimental evidence of the 1D model relevance in two dimensional
ferromagnetic thin films. Let's note that it is the effective DW width parallel
to DW propagation direction that matters in the 1D model formula, which is a
relevant change when dealing with zigzag DWs.Comment: 20 pages, 13 figure
Detection of small single-cycle signals by stochastic resonance using a bistable superconducting quantum interference device
We propose and experimentally demonstrate detecting small single-cycle and
few-cycle signals by using the symmetric double-well potential of a radio
frequency superconducting quantum interference device (rf-SQUID). We show that
the response of this bistable system to single- and few-cycle signals has a
non-monotonic dependence on the noise strength. The response, measured by the
probability of transition from initial potential well to the opposite one,
becomes maximum when the noise-induced transition rate between the two stable
states of the rf-SQUID is comparable to the signal frequency. Comparison to
numerical simulations shows that the phenomenon is a manifestation of
stochastic resonance.Comment: 5 pages 3 figure
A Wireless Covert Channel Based on Constellation Shaping Modulation
Wireless covert channel is an emerging covert communication technique which conceals the very existence of secret information in wireless signal including GSM, CDMA, and LTE. The secret message bits are always modulated into artificial noise superposed with cover signal, which is then demodulated with the shared codebook at the receiver. In this paper, we first extend the traditional KS test and regularity test in covert timing channel detection into wireless covert channel, which can be used to reveal the very existence of secret data in wireless covert channel from the aspect of multiorder statistics. In order to improve the undetectability, a wireless covert channel for OFDM-based communication system based on constellation shaping modulation is proposed, which generates additional constellation points around the standard points in normal constellations. The carrier signal is then modulated with the dirty constellation and the secret message bits are represented by the selection mode of the additional constellation points; shaping modulation is employed to keep the distribution of constellation errors unchanged. Experimental results show that the proposed wireless covert channel scheme can resist various statistical detections. The communication reliability under typical interference is also proved
Modeling and Analyzing User Behavior Risks in Online Shopping Processes Based on Data-Driven and Petri-Net Methods
With the rapid spread of e-commerce and e-payment, the increasing number of people choose online shopping instead of traditional buying way. However, the malicious user behaviors have a significant influence on the security of users' accounts and property. In order to guarantee the security of shopping environment, a method based on Complex Event Process (CEP) and Colored Petri nets (CPN) is proposed in this paper. CEP is a data-driven technology that can correlate and process a large amount of data according to Event Patterns, and CPN is a formal model that can simulate and verify the specifications of the online shopping processes. In this work, we first define the modeling scheme to depict the user behaviors and Event Patterns of online shopping processes based on CPN. The Event Patterns can be constructed and verified by formal methods, which guarantees the correctness of Event Patterns. After that, the Event Patterns are translated into Event Pattern Language (EPL) according to the corresponding algorithms. Finally, the EPLs can be inserted into the complex event processing engine to analyze the users' behavior flows in real-time. In this paper, we validate the effectiveness of the proposed method through case studies
A novel folate-modified self-microemulsifying drug delivery system of curcumin for colon targeting
Lin Zhang1*, Weiwei Zhu2*, Chunfen Yang1, Hongxia Guo1, Aihua Yu1, Jianbo Ji3, Yan Gao1, Min Sun1, Guangxi Zhai11Department of Pharmaceutical Engineering, College of Pharmacy, Shandong University, Jinan; 2Department of Pharmacy, Yantai Yuhuangding Hospital, Yantai; 3Department of Pharmacology, College of Pharmacy, Shandong University, Jinan, China*These authors contributed equally to the workBackground: The objective of this study was to prepare, characterize, and evaluate a folate-modified self-microemulsifying drug delivery system (FSMEDDS) with the aim to improve the solubility of curcumin and its delivery to the colon, facilitating endocytosis of FSMEDDS mediated by folate receptors on colon cancer cells.Methods: Ternary phase diagrams were constructed in order to obtain the most efficient self-emulsification region, and the formulation of curcumin-loaded SMEDDS was optimized by a simplex lattice experiment design. Then, three lipophilic folate derivatives (folate-polyethylene glycol-distearoylphosphatidylethanolamine, folate-polyethylene glycol-cholesteryl hemisuccinate, and folate-polyethylene glycol-cholesterol) used as a surfactant were added to curcumin-loaded SMEDDS formulations. An in situ colon perfusion method in rats was used to optimize the formulation of FSMEDDS. Curcumin-loaded FSMEDDS was then filled into colon-targeted capsules and the in vitro release was investigated. Cytotoxicity studies and cellular uptake studies was used in this research.Results: The optimal formulation of FSMEDDS obtained with the established in situ colon perfusion method in rats was comprised of 57.5% Cremophor® EL, 32.5% Transcutol® HP, 10% Capryol™ 90, and a small amount of folate-polyethylene glycol-cholesteryl hemisuccinate (the weight ratio of folate materials to Cremophor EL was 1:100). The in vitro release results indicated that the obtained formulation of curcumin could reach the colon efficiently and release the drug immediately. Cellular uptake studies analyzed with fluorescence microscopy and flow cytometry indicated that the FSMEDDS formulation could efficiently bind with the folate receptors on the surface of positive folate receptors cell lines. In addition, FSMEDDS showed greater cytotoxicity than SMEDDS in the above two cells.Conclusion: FSMEDDS-filled colon-targeted capsules are a potential carrier for colon delivery of curcumin.Keywords: curcumin, SMEDDS, folate receptor, colon targetin
Flow cytometry analysis of glucocorticoid receptor expression and binding in steroid-sensitive and steroid-resistant patients with systemic lupus erythematosus
Phylogenetic signal in gut microbial community rather than in rodent metabolic traits
This work was supported by the National Natural Science Foundation of China (32090020, 32271575, 32070449, 31872232, and 32270508) and the Strategic Priority Research Program of the Chinese Academy of Sciences (XDPB16).Peer reviewedPublisher PD
Correlation between systemic inflammatory response index and thyroid function: 2009-2012 NHANES results
AimsThis study investigates the relationship between the Systemic Inflammatory Response Index (SIRI) and thyroid function.MethodsUtilizing data from the National Health and Nutrition Examination Survey (NHANES) 2009-2012, we excluded participants lacking SIRI or thyroid function data, those under 20 years, and pregnant individuals. SIRI was determined using blood samples. We conducted weighted multivariate regression and subgroup analyses to discern the independent relationship between SIRI and thyroid function.ResultsThe study included 1,641 subjects, with an average age of 47.26Ā±16.77 years, including 48.65% males and 51.35% females. The population was divided into three SIRI-based groups (Q1-Q3). Q3, compared to Q1, exhibited higher age-at-onset, greater male prevalence, and increased levels of FT3, FT4, TT4, leukocytes, and triglycerides. This group also showed a higher incidence of diabetes, hypertension, and smoking. Notably, Q1 had lower LDL and HDL levels. SIRI maintained a positive association with FT4 (Ī² = 0.01, 95% CI = 0.00-0.03, P for trend = 0.0071), TT4 (Ī² = 0.20, 95% CI = 0.10, 0.31, P for trend=0.0001), and TPOAb (Ī² = 8.0, 95% CI = 1.77-14.30, P for trend = 0.0120), indicating that each quartile increase in SIRI corresponded to a 0.01 ng/dL increase in FT4, a 0.2 g/dL increase in TT4, and an 8.03 IU/mL rise in TPOAb. The subgroup analysis suggested the SIRI-thyroid function correlation was influenced by hypertension.ConclusionInflammation may impact the development and progression of thyroid function disorders. Proactive anti-inflammatory treatment might mitigate thyroid abnormalities
Modeling and Analyzing User Behavior Risks in Online Shopping Processes Based on Data-Driven and Petri-Net Methods
With the rapid spread of e-commerce and e-payment, the increasing number of people choose online shopping instead of traditional buying way. However, the malicious user behaviors have a significant influence on the security of usersā accounts and property. In order to guarantee the security of shopping environment, a method based on Complex Event Process (CEP) and Colored Petri nets (CPN) is proposed in this paper. CEP is a data-driven technology that can correlate and process a large amount of data according to Event Patterns, and CPN is a formal model that can simulate and verify the specifications of the online shopping processes. In this work, we first define the modeling scheme to depict the user behaviors and Event Patterns of online shopping processes based on CPN. The Event Patterns can be constructed and verified by formal methods, which guarantees the correctness of Event Patterns. After that, the Event Patterns are translated into Event Pattern Language (EPL) according to the corresponding algorithms. Finally, the EPLs can be inserted into the complex event processing engine to analyze the usersā behavior flows in real-time. In this paper, we validate the effectiveness of the proposed method through case studies
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