201 research outputs found
Community prevalence of carbapenemase-producing Gram-negative bacteria
Purpose: To raise awareness of carbapenemase-producing organisms, identify “at-risk” patients when admitted in a medical healthcare facility, and to outline effective infection prevention and control measures in order to halt the entry and spread of these organisms.
Methods: A total of 1043 un-duplicated urine specimens of healthy volunteers who had no travel history or history of hospitalization were screened. The carbapenemase genotype of each imipenem-resistant strain was determined. Molecular typing and homology analysis of the main carbapenemase-producing strains were used to reveal the mode of transmission of resistance genes. Through transfer joint experiments, the potential risk of spread of carbapenemase genes was assessed.
Results: A total of 19 carbapenemase-producing strains from 1,043 non-duplicated healthy volunteers (1.82 %) were identified. The main carbapenemase-producing organism was E. coli (42.1 %, 8/19). The main carbapenemase genotype of E. coli was blaKPC-2 (7 strains). Results from multi-locus sequence typing (MLST) indicated that 7 E. coli isolates belonged to ST-10, ST-101, ST-131, ST-405, ST-410 and ST-1193 and ST-2562. Homologous cluster analysis revealed that the sequence types among the 7 E. coli were high in diversity. The blaKPC-2 gene was successfully transferred from these isolates to 10.22-14 via conjugation. All recipient cells showed marked decreases in carbapenem sensitivity to imipenem (p < 0.05)). The degrees of conjugation were 2.10±0.12 ×10-4, 1.96±0.14×10-4, 2.72±0.18 ×10-4, 3.15±0.20 × 10-4, 2.92±0.23 ×10-4, 3.50±0.20 ×10-4 and 4.12±0.24 ×10-4 in recipient cells of TC7.23-51, TC8.9-42, TC8.15-11, TC8.23-59-3, TC8.23-83, TC9.08-47 and TC10.13-15, respectively.
Conclusion: The findings demonstrate the pattern and features of carbapenemase-insensitive E. coli. The blaKPC-2 was the main community-prevalent gene of carbapenem-resistant E. coli. In view of increasing incidence of resistance to multi-drug therapy, surveillance of insensitivity to antibiotics is vital, especially urinary system infection due to carbapenem-insensitive E. coli
Comparison of retinal thickness measurements of normal eyes between topcon algorithm and a graph based algorithm
To assess the agreement between Topcon built-in algorithm and our developed graph based algorithm, the retinal thickness of 9-sectors on an Early Treatment of Diabetic Retinopathy Study(ETDRS) chart measurements for normal subjects was compared. A total of fifty eyes were enrolled in this study. The overall and sectoral thickness on ETDRS chart were calculated using Topcon built-in algorithm and our developed three-dimensional graph based algorithm. Correlation analysis and agreement analysis were performed between the commercial algorithm and our algorithm. A high degree of correlation was found between the results obtained from the two methods was from 0.856 to 0.960. It’s showed that our developed graph based algorithm can provide excellent performance similar to Topcon algorithm
Passive Inference Attacks on Split Learning via Adversarial Regularization
Split Learning (SL) has emerged as a practical and efficient alternative to
traditional federated learning. While previous attempts to attack SL have often
relied on overly strong assumptions or targeted easily exploitable models, we
seek to develop more practical attacks. We introduce SDAR, a novel attack
framework against SL with an honest-but-curious server. SDAR leverages
auxiliary data and adversarial regularization to learn a decodable simulator of
the client's private model, which can effectively infer the client's private
features under the vanilla SL, and both features and labels under the U-shaped
SL. We perform extensive experiments in both configurations to validate the
effectiveness of our proposed attacks. Notably, in challenging but practical
scenarios where existing passive attacks struggle to reconstruct the client's
private data effectively, SDAR consistently achieves attack performance
comparable to active attacks. On CIFAR-10, at the deep split level of 7, SDAR
achieves private feature reconstruction with less than 0.025 mean squared error
in both the vanilla and the U-shaped SL, and attains a label inference accuracy
of over 98% in the U-shaped setting, while existing attacks fail to produce
non-trivial results.Comment: 19 pages, 20 figure
An automated framework of inner segment/outer segment defect detection for retinal SD-OCT images
The integrity of inner segment/outer segment (IS/OS) has high correlation with lower visual acuity in patients suffering from blunt trauma. An automated 3D IS/OS defect detection method based on the SD-OCT images was proposed. First, 11 surfaces were automatically segmented using the multiscale 3D graph-search approach. Second, the sub-volumes between surface 7 and 8 containing IS/OS region around the fovea (diameter of mm) were extracted and flattened based on the segmented retinal pigment epithelium layer. Third, 5 kinds of texture based features were extracted for each voxel. A KNN classifier was trained and each voxel was classified as disrupted or nondisrupted and the responding defect volume was calculated. The proposed method was trained and tested on 9 eyes from 9 trauma subjects using the leave-one-out cross validation method. The preliminary results demonstrated the feasibility and efficiency of the proposed method
WGCNA based identification of hub genes associated with cold response and development in Apis mellifera metamorphic pupae
Honeybee is a crucial pollinator in nature, and plays an indispensable role in both agricultural production and scientific research. In recent decades, honeybee was challenged with health problems by biotic and abiotic stresses. As a key ecological factor, temperature has been proved to have an impact on the survival and production efficiency of honeybees. Previous studies have demonstrated that low temperature stress can affect honeybee pupation and shorten adult longevity. However, the molecular mechanism underlying the effects of low temperatures on honeybee growth and development during their developmental period remain poorly understood. In this paper, the weighted gene co-expression analysis (WGCNA) was employed to explore the molecular mechanisms underpinnings of honeybees’ respond to low temperatures (20°C) during four distinct developmental stages: large-larvae, prepupae, early-pupae and mid-pupae. Through an extensive transcriptome analysis, thirteen gene co-expression modules were identified and analyzed in relation to honeybee development and stress responses. The darkorange module was found to be associated with low temperature stress, with its genes primarily involved in autophagy-animal, endocytosis and MAPK signaling pathways. Four hub genes were identified within this module, namely, loc726497, loc409791, loc410923, and loc550857, which may contribute to honeybee resistance to low temperature and provide insight into the underlying mechanism. The gene expression patterns of grey60 and black modules were found to correspond to the developmental stages of prepupae and early-pupae, respectively, with the hub genes loc409494, loc725756, loc552457, loc726158, Ip3k and Lcch3 in grey60 module likely involved in brain development, and the hub genes loc410555 in black module potentially related to exoskeleton development. The brown module genes exhibited a distinct pattern of overexpression in mid-pupae specimens, with genes primarily enriched in oxidative phosphorylation, citrate cycle and other pathways, which may be related to the formation of bee flying muscle. No related gene expression module was found for mature larvae stage. These findings provide valuable insights into the developmental process of honeybees at molecular level during the capped brood stage
A Wide Bandwidth Circularly Polarized Microstrip Antenna Array Using Sequentially Rotated Feeding Technique
Abstract-A wide bandwidth circularly polarized microstrip antenna array using sequentially rotated feeding technique is presented in this paper. First a stacked microstrip antenna with tuning stub is designed, which meets wide bandwidth application. Then sequentially rotated feeding technique is introduced, basing on which a 4 element stacked microstrip antenna array with preferable axial ratio performance is achieved. The corresponding antenna array is fabricated and measured, the results of which shows that the antenna has the advantages of wide bandwidth, high gain and low axial radio, which has good application foreground
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