140 research outputs found
Optimal Pilots for Anti-Eavesdropping Channel Estimation
Anti-eavesdropping channel estimation (ANECE) is a method that uses specially
designed pilot signals to allow two or more full-duplex radio devices each with
one or more antennas to estimate their channel state information (CSI)
consistently and at the same time prevent eavesdropper (Eve) with any number of
antennas from obtaining its CSI consistently. This paper presents optimal
designs of the pilots for ANECE based on two criteria. The first is the mean
squared error (MSE) of channel estimation for the users, and the second is the
mutual information (MI) between the pilot-driven signals observed by the users.
Closed-form optimal pilots are shown under the sum-MSE and sum-MI criteria
subject to a symmetric and isotropic condition. Algorithms for computing the
optimal pilots are shown for general cases. Fairness issues for three or more
users are discussed. The performances of different designs are compared
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Using the Chinese version of Memorial Delirium Assessment Scale to describe postoperative delirium after hip surgery
Objective:: Memorial Delirium Assessment Scale (MDAS) assesses severity of delirium. However, whether the MDAS can be used in a Chinese population is unknown. Moreover, the optimal postoperative MDAS cutoff point for describing postoperative delirium in Chinese remains largely to be determined. We therefore performed a pilot study to validate MDAS in the Chinese language and to determine the optimal postoperative MDAS cutoff point for delirium. Methods:: Eighty-two patients (80 ± 6 years, 21.9% male), who had hip surgery under general anesthesia, were enrolled. The Confusion Assessment Method (CAM) and Mini-Mental State Examination (MMSE) were administered to the patients before surgery. The CAM and MDAS were performed on the patients on the first, second and fourth postoperative days. The reliability and validity of the MDAS were determined. A receiver operating characteristic (ROC) curve was used to determine the optimal Chinese version MDAS cutoff point for the identification of delirium. Results:: The Chinese version of the MDAS had satisfactory internal consistency (α = 0.910). ROC analysis obtained an average optimal MDAS cutoff point of 7.5 in describing the CAM-defined postoperative delirium, with an area under the ROC of 0.990 (95% CI 0.977–1.000, P < 0.001). Conclusions:: The Chinese version of the MDAS had good reliability and validity. The patients whose postoperative Chinese version MDAS cutoff point score was 7.5 would likely have postoperative delirium. These results have established a system for a larger scale study in the future
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Numerical investigation of GHz repetition rate fundamentally mode-locked all-fiber lasers
GHz repetition rate fundamentally mode-locked lasers have attracted great interest for a variety of scientific and practical applications. A passively mode-locked laser in all-fiber format has the advantages of high stability, maintenance-free operation, super compactness, and reliability. In this paper, we present numerical investigation on passive mode-locking of all-fiber lasers operating at repetition rates of 1-20 GHz. Our calculations show that the reflectivity of the output coupler, the small signal gain of the doped fiber, the total net cavity dispersion, and the modulation depth of the saturable absorber are the key parameters for producing stable fundamentally mode-locked pulses at GHz repetition rates in very short all-fiber linear cavities. The instabilities of GHz repetition rate fundamentally mode-locked all-fiber lasers with different parameters were calculated and analyzed. Compared to a regular MHz repetition rate mode-locked all-fiber laser, the pump power range for the mode-locking of a GHz repetition rate all-fiber laser is much larger due to the several orders of magnitude lower accumulated nonlinearity in the fiber cavity The presented numerical study provides valuable guidance for the design and development of highly stable mode-locked all-fiber lasers operating at GHz repetition rates.National Science Foundation Engineering Research Center for Integrated Access Networks [EEC-0812072]; Technology Research Initiative Fund (TRIF) Photonics Initiative of the University of Arizona; National Natural Science Foundation of China (NSFC) [61575075]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
A real-world study of anlotinib as third-line or above therapy in patients with her-2 negative metastatic breast cancer
BackgroundAntiangiogenic agents provides an optional treatment strategy for patients with metastatic breast cancer. The present study was conducted to evaluate the efficacy and safety of anlotinib as third-line or above therapy for patients with HER-2 negative metastatic breast cancer.MethodsPatients with HER-2 negative metastatic breast cancer who have failed from prior therapy and treated with anlotinib monotherapy or combined with chemotherapy or immunotherapy from June 2018 to December 2020 were retrospectively analyzed based on real-world clinical practice. The primary end point was progression free survival (PFS). Secondary end points included objective response rate (ORR), disease control rate (DCR), overall survival (OS) and safety.Results47 patients with HER-2 negative metastatic breast cancer received anlotinib monotherapy or combination therapy as third-line or above therapy. In the general population, 10 patients achieved PR, 25 patients had SD and 12 patients had PD. The overall ORR and DCR were 21.3% and 74.5%, respectively. Subgroup analysis suggested that there were no statistically significant differences in ORR and DCR with respect to HR status (positive vs. negative), treatment programs (monotherapy vs. combination) and treatment type in combination group (chemotherapy vs. immunotherapy). The patients who did not received previously anti-angiogenesis therapy had superior DCR (84.8% vs. 50.0%, P=0.012). Median PFS and OS were 5.0 months (95% CI=4.3-5.7) and 21.0 (95% CI=14.9-27.1) months, respectively. The PFS (6.5m vs. 3.5m, P=0.042)and OS (28.2m vs. 12.6m, P=0.040) were better in HR positive patients than HR negative patients. And simultaneously, patients who received anlotinib combination therapy obtained better PFS (5.5m vs. 3.0m, P=0.045). The incidence of Grade 3-4 adverse events(AEs) was 31.9%.ConclusionsAnlotinib monotherapy or combination therapy provide a viable third-line or above therapeutic strategy in patients with HER-2 negative metastatic breast cancer, a median PFS of 5.0 months was obtained with well tolerated toxicity
Real-Time Segmentation Method of Lightweight Network For Finger Vein Using Embedded Terminal Technique
Because the existing finger vein segmentation networks are too large and not suitable for implementation in mobile terminals, the reduction of the parameters of the lightweight network leads to the reduction of the segmentation index, and the long-running time of deep network on hardware platforms; this paper proposes a lightweight real-time segmentation method for finger veins based on embedded terminal technique. In the preprocessing stage of the algorithm, the data is greatly expanded by randomly selecting the center to obtain sub-blocks on each image of the training set. The network first uses deep separable convolution to greatly reduce the U-Net parameters of a basic network and introduces an attention module to reorder the features to improve network performance, followed by a preliminary lightweight network Dinty-NetV1. Second, the Ghost module is added to the deep separable convolution, and the feature map of the network part is obtained through a cheap operation so that the network is further compressed to obtain Dinty-NetV2. After adding channel shuffle, all the characteristic channels are evenly shuffled and reorganized to obtain Dinty-NetV3. Finally, a study of the filter norm yields the distribution characteristics of the finger vein picture features. By using the geometric median pruning method, the network models for each stage of the algorithm proposed in this paper achieved better segmentation performance and shorter split time after pruning. The overall Dinty-NetV3 model size is only less than 9% of the U-Net and Mult-Adds is less than 2% of the U-Net with the same structure. After testing on two-finger vein datasets SDU-FV and MMCUBV-6000, we confirm that the performance of Dinty-NetV3 surpasses all previously proposed classic compression model algorithms and it is not inferior to more complex and huge networks such as U-Net, DU-Net, and R2U-Net. The proposed algorithm has advantages in terms of time needed to train the network, and we verify its universality using NVIDIA's full range of embedded terminals
Erratum: Author Correction: Midbrain Circuit Regulation of Individual Alcohol Drinking Behaviors in Mice (Nature Communications (2017) 8 1 (2220))
The original version of this Article contained an error in the spelling of the author Scott Edwards, which was incorrectly given as Scott Edward. This has now been corrected in both the PDF and HTML versions of the Article
Midbrain circuit regulation of individual alcohol drinking behaviors in mice
Alcohol-use disorder (AUD) is the most prevalent substance-use disorder worldwide. There is substantial individual variability in alcohol drinking behaviors in the population, the neural circuit mechanisms of which remain elusive. Utilizing in vivo electrophysiological techniques, we find that low alcohol drinking (LAD) mice have dramatically higher ventral tegmental area (VTA) dopamine neuron firing and burst activity. Unexpectedly, VTA dopamine neuron activity in high alcohol drinking (HAD) mice does not differ from alcohol naive mice. Optogenetically enhancing VTA dopamine neuron burst activity in HAD mice decreases alcohol drinking behaviors. Circuit-specific recordings reveal that spontaneous activity of nucleus accumbens-projecting VTA (VTA-NAc) neurons is selectively higher in LAD mice. Specifically activating this projection is sufficient to reduce alcohol consumption in HAD mice. Furthermore, we uncover ionic and cellular mechanisms that suggest unique neuroadaptations between the alcohol drinking groups. Together, these data identify a neural circuit responsible for individual alcohol drinking behaviors
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