3,551 research outputs found

    Investigation on the changes of corneal curvature after non-phacoemulsification in small-incision cataract surgery with intraocular lens implantation

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    AIM: To investigate the changes of corneal curvature after non-phacoemulsification in small-incision cataract surgery with intraocular lens implantation and discuss the essence of iatrogenic astigmatism. <p>METHODS: In this study, the horizontal corneal curvature(HCC)and vertical corneal curvature(VCC)of 99 patients(116 eyes)were documented before and after cataract surgery,with the postoperative follow-up of 3d; 1, 2wk; 1, 3, 6mo; 1, 2, 3a. The difference value of the HCC and the VCC between preoperation and postoperation were calculated and statistically analyzed. <p>RESULTS: The VCC was deceased by 2.01D, while the HCC was increased by 1.62D on the 3d after surgery; the difference value of the HCC and VCC were both decreased acutely in the 3mo postoperationly(the difference value of the VCC was -0.52D and HCC was 0.46D); the difference value of the HCC and VCC both were decreased mildly after 3mo of postoperation, There was no significant difference between the difference value of HCC(0.29D)and VCC(-0.29D)at 6mo(<i>P</i>=0.801); VCC was still smaller than that of preoperation(-0.26D), and HCC was larger than that of preoperation(0.25D)at the 3a. Paired <i>t</i> test was performed in these curvature differences, which both decreased apparently from 3d to 6mo after surgery(<i>P</i><0.001), while they stayed still from 6mo to 3a postoperatively(VCC: <i>P</i>=0.284; HCC:<i>P</i>=1.000). <p>CONCLUSION: It remains astigmatism for a short time after small-incision cataract surgery and the treatment requires improvement so as to minimize the astigmatism as much as possible

    Fusion-based Few-Shot Morphing Attack Detection and Fingerprinting

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    The vulnerability of face recognition systems to morphing attacks has posed a serious security threat due to the wide adoption of face biometrics in the real world. Most existing morphing attack detection (MAD) methods require a large amount of training data and have only been tested on a few predefined attack models. The lack of good generalization properties, especially in view of the growing interest in developing novel morphing attacks, is a critical limitation with existing MAD research. To address this issue, we propose to extend MAD from supervised learning to few-shot learning and from binary detection to multiclass fingerprinting in this paper. Our technical contributions include: 1) We propose a fusion-based few-shot learning (FSL) method to learn discriminative features that can generalize to unseen morphing attack types from predefined presentation attacks; 2) The proposed FSL based on the fusion of the PRNU model and Noiseprint network is extended from binary MAD to multiclass morphing attack fingerprinting (MAF). 3) We have collected a large-scale database, which contains five face datasets and eight different morphing algorithms, to benchmark the proposed few-shot MAF (FS-MAF) method. Extensive experimental results show the outstanding performance of our fusion-based FS-MAF. The code and data will be publicly available at https://github.com/nz0001na/mad maf

    Study on the control algorithm for lower limb exoskeleton based on ADAMS/Simulink co-simulation

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    A sliding mode control algorithm based on proportional switching function was developed to make the lower limb exoskeleton more fit the human walking gait trajectory. It could improve the comfort of the exoskeleton wearer and enhance the reliability of the system. The three-dimensional mechanical model of the exoskeleton built using software SolidWorks was introduced to ADAMS and then the model parameters were set. The model was combined with the software MATLAB so that the human-machine cooperation control algorithm for lower limb exoskeleton based on ADAMS and Simulink co-simulation was developed. The simulation result was compared with the desired trajectory and the trajectory under PID control. The research discovered that the ability of trajectory tracking under the sliding mode control was much better than that under PID control. It provided an important theoretical basis for the research on human-machine cooperation control algorithm

    Insights into high temperature pretreatment on cellulase processing of bamboo

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    Bamboo processing was performed with commercial cellulase. The properties of cellulase and the effect of high temperature pretreatment on cellulase hydrolysis of bamboo were investigated. Results indicated that cellulase hydrolysis performed fast and dramatically within 30 minutes, and then gradually reached its balance. It was found that pretreatment played an active role in cellulase processing, which enhanced the saccharification of bamboo and benefited high-molecular-weight lignin degradation and removal. Additionally, a better performance of bamboo processing was achieved under the cellulase concentration of 15IU in total reaction system of 100 ml at 50°C, pH 4.8, together with the high temperature pretreatment of 120°C for 15 minutes

    Effects of ACE inhibition on endothelial progenitor cell mobilization and prognosis after acute myocardial infarction in type 2 diabetic patients

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    OBJECTIVE: We aimed to assess the chemotactic response of endothelial progenitor cells to angiotensin-converting enzyme inhibitors in T2DM patients after acute myocardial infarction, as well as the associated prognosis. METHODS: Sixty-eight T2DM patients with acute myocardial infarction were randomized to either receive or not receive daily oral perindopril 4 mg, and 36 non-diabetic patients with acute myocardial infarction were enrolled as controls. The numbers of circulating CD45−/low+CD34+CD133+KDR+ endothelial progenitor cells, as well as the stromal cell-derived factor-α and high-sensitivity C reactive protein levels, were measured before acute percutaneous coronary intervention and on days 1, 3, 5, 7, 14, and 28 after percutaneous coronary intervention. Patients were followed up for 6 months. Chinese Clinical Trial Registry: ChiCTR-TRC-12002599. RESULTS: T2DM patients had lower circulating endothelial progenitor cell counts, decreased plasma vascular endothelial growth factor and α levels, and higher plasma high-sensitivity C reactive protein levels compared with non-diabetic controls. After receiving perindopril, the number of circulating endothelial progenitor cells increased from day 3 to 7, as did the plasma levels of vascular endothelial growth factor and stromal cell-derived factor-α, compared with the levels in T2DM controls. Plasma high-sensitivity C reactive protein levels in the treated group decreased to the same levels as those in non-diabetic controls. Furthermore, compared with T2DM controls, the perindopril-treated T2DM patients had lower cardiovascular mortality and occurrence of heart failure symptoms (

    Density alteration in non-physiological cells

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    In the present study an important phenomenon of cells was discovered: the change of intracellular density in cell&#x27;s response to drug and environmental factors. For convenience, this phenomenon is named as &#x22;density alteration in non-physiological cells&#x22; ( DANCE). DANCE was determined by discontinuous sucrose gradient centrifugation (DSGC), in which cells were separated into several bands. The number and position of the bands in DSGC varied with the change of cell culture conditions, drugs, and physical process, indicating that cell&#x27;s response to these factors was associated with alteration of intracellular density. Our results showed that the bands of cells were molecularly different from each other, such as the expression of some mRNAs. For most cells tested, intracellular density usually decreased when the cells were in bad conditions, in presence of drugs, or undergoing pathological changes. However, unlike other tissue cells, brain cells showed increased intracellular density in 24 hrs after the animal death. In addition, DANCE was found to be related to drug resistance, with higher drug-resistance in cells of lower intracellular density. Further study found that DANCE also occurred in microorganisms including bacteria and fungus, suggesting that DANCE might be a sensitive and general response of cells to drugs and environmental change. The mechanisms for DANCE are not clear. Based on our study the following causes were hypothesized: change of metabolism mode, change of cell membrane function, and pathological change. DANCE could be important in medical and biological sciences. Study of DANCE might be helpful to the understanding of drug resistance, development of new drugs, separation of new subtypes from a cell population, forensic analysis, and importantly, discovery of new physiological or pathological properties of cells

    Effects of mindfulness-based stress reduction on compliance in primary open angle glaucoma patients with topical medication

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    AIM: To explore the effects of mindfulness-based stress reduction(MBSR)on anxiety, compliance and visual function in primary open angle glaucoma(POAG)patients.METHODS:Totally 64 patients, who were treated with topical medication and were diagnosed with POAG in the department of ophthalmology at Shaanxi Provincial People's Hospital, were randomly divided into the intervention group(n=32)and the control group(n=32). Both groups received conventional mental health education while the intervention group was complemented with MBSR intervention. The patient's anxiety status, compliance rates and MD before and after the intervention were evaluated.RESULTS:After the MBSR intervention, the scores of HAMA of the intervention group were significantly lower than that of the control group(PPCONCLUSION:The MBSR intervention can effectively relieve the anxiety of patients and improve the compliance in primary open angle glaucoma patients. It can be promoted and put into clinical application
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