1,905 research outputs found
Genomic epidemiology of Vibrio cholerae reveals the regional and global spread of two epidemic non-toxigenic lineages
Non-toxigenic Vibrio cholerae isolates have been found associated with diarrheal disease globally, however, the global picture of non-toxigenic infections is largely unknown. Among non-toxigenic V. cholerae, ctxAB negative, tcpA positive (CNTP) isolates have the highest risk of disease. From 2001 to 2012, 71 infectious diarrhea cases were reported in Hangzhou, China, caused by CNTP serogroup O1 isolates. We sequenced 119 V. cholerae genomes isolated from patients, carriers and the environment in Hangzhou between 2001 and 2012, and compared them with 850 publicly available global isolates. We found that CNTP isolates from Hangzhou belonged to two distinctive lineages, named L3b and L9. Both lineages caused disease over a long time period with usually mild or moderate clinical symptoms. Within Hangzhou, the spread route of the L3b lineage was apparently from rural to urban areas, with aquatic food products being the most likely medium. Both lineages had been previously reported as causing local endemic disease in Latin America, but here we show that global spread of them has occurred, with the most likely origin of L3b lineage being in Central Asia. The L3b lineage has spread to China on at least three occasions. Other spread events, including from China to Thailand and to Latin America were also observed. We fill the missing links in the global spread of the two non-toxigenic serogroup O1 V. cholerae lineages that can cause human infection. The results are important for the design of future disease control strategies: surveillance of V. cholerae should not be limited to ctxAB positive strains
Role of salivary anti-SSA/B antibodies for diagnosing primary Sjögren’s syndrome
The diagnosis of primary Sjögren’s syndrome (pSS) is complex, and the saliva test is a potential method to improve the existing diagnostic criteria.
Objective: To estimate the diagnostic accuracy of salivary anti-SSA/B antibodies in primary Sjögren’s syndrome
(pSS), and to analyze their correlations with clinical and laboratory profiles.
Study Design: This study enrolled 100 pSS patients and 140 non-pSS controls, including 40 rheumatoid arthritis
(RA) patients, 40 systemic lupus erythematosus (SLE) patients, and 60 healthy controls. Unstimulated whole saliva and stimulated parotid saliva samples were collected from the subjects. Salivary anti-SSA/B antibodies were
measured using an enzyme-linked immunosorbent assay (ELISA). Clinical and laboratory data were retrieved
from the medical records.
Results: In the pSS group, the sensitivity of anti-SSA and anti-SSB antibodies in whole saliva was 49% and 29%,
respectively, and the specificity was 87.5% and 95%. The sensitivity of anti-SSA and anti-SSB antibodies in parotid saliva was 32% and 8%, respectively, and the specificity was 95.52% and 97.86%, respectively. In the pSS
group, the diagnostic accuracy of anti-SSA/B antibodies in whole saliva was significantly higher than in parotid
saliva (
p
<0.05), but was significantly lower than in serum (
p
<0.05). The salivary flow rate in the pSS group posi
-
tive for whole salivary anti-SSA was significantly lower than in the negative group (
p
<0.05). The prevalence of
rheumatoid factor and antinuclear factor were significantly higher in salivary SSB-positive pSS patients than in
SSB-negative patients (
p
<0.05).
Conclusions: Compared to parotid saliva, whole saliva is a more suitable diagnostic fluid. Using salivary anti-
SSA/B antibodies as a single test item is insufficient given the relatively low sensitivity. Further studies should investigate the possibility of combining tests for different salivary autoantibodies as a method for diagnosing pSS
Design of automotive structural components using high strength sheet steels structural strength of cold-formed steel I-beams and hat sections subjected to web crippling load
INTRODUCTION When cold-formed steel beam webs are subjected to partial edge loading, they may fail by web crippling rather than bending of the beam. Web crippling is caused by a highly localized intensity of the load or reaction. Because of the complexity of the web crippling behavior, empirical expressions are presently used for the design of cold-formed steel beams in buildings and automotive structural components to prevent web crippling. 1,2,3. The research on the structural behavior of cold-formed steel beam webs subjected to web crippling has been conducted at Cornell University and the University of Missouri-Rolla (UMR) under the sponsorship of the American Iron and Steel Institute (AISI).4,5 Since 1982, additional work has been performed at the University of Missouri-Rolla, Inland Steel Company, and Ford Motor Company to investigate the web crippling strength of automotive structural components using high strength sheet steels. 6-9 The research findings of the UMR study were summarized in the Eighth Progress Report. 7 In the UMR Fifth and Eighth Progress Reports, it was noted that if the I-beam specimens are subjected to the end one-flange loading without connecting the beam flange to the bearing plate, the failure of all sections used in the pilot tests occured by cross-bending of the flange about the connector location as shown in Fig. 1 instead of the conventional web crippling. This type of failure will be referred to as a flange cross-bending mode of failure in this report. It seems to be dependent primarily on the bend radius, the thickness of the web, the location of connectors and other parameters. Figure 2 shows the failure of an I-beam subjected to end one-flange loading. The tested loads for the specimens having the flange cross-bending type of failure were lower than those caused by the conventional web crippling. The purpose of this brief study reported herein was to review the test results described in Ref. 6 for the flange cross-bending type of failure of cold-formed steel I-beams using high strength sheet steels and to develop some new design criteria, if possible. Because of the limited number of test results, the present investigation can only be treated as a preliminary study of the problem. An extensive experimental work will be needed for the development of general design criteria. Section II contains a review of the experimental research results described in Ref. 6. In Section III, an analytical study of this type of failure mode for cold-formed steel I-beams is presented by using the finite element method. The development of an empirical expression for predicting the ultimate load is discussed in Section IV. Also included in this section is the comparison of test results and predicted values based on the newly developed equations for flange cross-bending failure. In addition to the study of the web crippling strength of I-beams, this report also evaluates the results of 157 beam tests using hat sections. These tests were conducted recently at the Research Laboratories of Inland Steel Company. Section V includes the information on beam specimens 10 and comparisons of the tested and predicted failure loads on the basis of the design recommendations proposed in Ref. 7. Finally, conclusions are drawn in Section VI
A Prospective Randomized Study of Adjuvant Chemotherapy in Resected Stage IIIA-N2 Non-small Cell Lung Cancer
Background and objective Lung cancer is one of the leading cause of cancer-related death around the world. Surgery is the primary treatment for patients with stage I, II, or IIIA non-small cell lung cancer (NSCLC). However, longterm survival of NSCLC patients after surgery alone is largely unsatisfactory. We undertook to determine whether adjuvant vinorelbine/paclitaxel plus carboplatin prolong overall survival among patients with completely resected stage IIIA-N2 nonsmall cell lung cancer. Methods We randomly assigned patients with completely resected stage IIIA-N2 non-small cell lung cancer to vinorelbine/paclitaxel plus carboplatin or to observation. Results A total of 150 patients (1999-2003) underwent randomization to vinorelbine/paclitaxel plus carboplatin (79 patients) or observation. In both groups, the median age was 57 years, 73 percent were male, and 28 percents had squamous carcinoma. Chemotherapy caused neutropenia in 82 percents of patients (including grade 3 and 4 neutropenia in 42 percent) and there was no treatment-related death observed in this trial. After median follow-up of 39 months (range 1-110), overall survival was significantly prolonged in the chemotherapy group as compared with the observation group (33 months versus 24 months, χ2=4.363, P=0.037), as was disease-free survival (32 months versus 20 months, χ2=5.413, P=0.020). Five-year overall survival rates were 31.1 percent and 19.1 percent, respectively. Conclusion Adjuvant vinorelbine/paclitaxel plus carboplatin have an acceptable level of toxicity and prolongs disease-free and overall survival among patients with completely resected stage IIIA-N2 non-small cell lung cancer
Poly[diaquaÂbis[ÎĽ2-2,4-(dichloroÂphenoxy)Âacetato-Îş2 O:O′]iron(II)]
In the title compound, [Fe(C8H5Cl2O3)2(H2O)2]n, the FeII atom is located on an inversion center. It is coordinated by four O atoms from four 2,4-dichloroÂphenoxyÂacetate ligands and two water molÂecules, displaying a distorted octaÂhedral geometry. The carboxylÂate groups of the 2,4-dichloroÂphenoxyÂacetate ligands link the Fe atoms, forming a polymeric layered network in the bc plane. IntraÂlayer O—Hâ‹ŻO hydrogen bonds enhance the stability of the two-dimensional network
Observation of quantum fingerprinting beating the classical limit
Quantum communication has historically been at the forefront of advancements,
from fundamental tests of quantum physics to utilizing the quantum-mechanical
properties of physical systems for practical applications. In the field of
communication complexity, quantum communication allows the advantage of an
exponential reduction in the information transmitted over classical
communication to accomplish distributed computational tasks. However, to date,
demonstrating this advantage in a practical setting continues to be a central
challenge. Here, we report an experimental demonstration of a quantum
fingerprinting protocol that for the first time surpasses the ultimate
classical limit to transmitted information. Ultra-low noise superconducting
single-photon detectors and a stable fibre-based Sagnac interferometer are used
to implement a quantum fingerprinting system that is capable of transmitting
less information than the classical proven lower bound over 20 km standard
telecom fibre for input sizes of up to two Gbits. The results pave the way for
experimentally exploring the advanced features of quantum communication and
open a new window of opportunity for research in communication complexity and
testing the foundations of physics.Comment: 19 pages, 4 figure
SMAT: Simultaneous and Self-Reinforced Mapping and Tracking in Dynamic Urban Scenariosorcing Framework for Simultaneous Mapping and Tracking in Unbounded Urban Environments
Despite the increasing prevalence of robots in daily life, their navigation
capabilities are still limited to environments with prior knowledge, such as a
global map. To fully unlock the potential of robots, it is crucial to enable
them to navigate in large-scale unknown and changing unstructured scenarios.
This requires the robot to construct an accurate static map in real-time as it
explores, while filtering out moving objects to ensure mapping accuracy and, if
possible, achieving high-quality pedestrian tracking and collision avoidance.
While existing methods can achieve individual goals of spatial mapping or
dynamic object detection and tracking, there has been limited research on
effectively integrating these two tasks, which are actually coupled and
reciprocal. In this work, we propose a solution called SMAT (Simultaneous
and Self-Reinforced Mapping and Tracking) that integrates a front-end dynamic
object detection and tracking module with a back-end static mapping module.
SMAT leverages the close and reciprocal interplay between these two modules
to efficiently and effectively solve the open problem of simultaneous tracking
and mapping in highly dynamic scenarios. We conducted extensive experiments
using widely-used datasets and simulations, providing both qualitative and
quantitative results to demonstrate SMAT's state-of-the-art performance in
dynamic object detection, tracking, and high-quality static structure mapping.
Additionally, we performed long-range robotic navigation in real-world urban
scenarios spanning over 7 km, which included challenging obstacles like
pedestrians and other traffic agents. The successful navigation provides a
comprehensive test of SMAT's robustness, scalability, efficiency, quality,
and its ability to benefit autonomous robots in wild scenarios without
pre-built maps.Comment: homepage: https://sites.google.com/view/smat-na
Source attack of decoy-state quantum key distribution using phase information
Quantum key distribution (QKD) utilizes the laws of quantum mechanics to
achieve information-theoretically secure key generation. This field is now
approaching the stage of commercialization, but many practical QKD systems
still suffer from security loopholes due to imperfect devices. In fact,
practical attacks have successfully been demonstrated. Fortunately, most of
them only exploit detection-side loopholes which are now closed by the recent
idea of measurement-device-independent QKD. On the other hand, little attention
is paid to the source which may still leave QKD systems insecure. In this work,
we propose and demonstrate an attack that exploits a source-side loophole
existing in qubit-based QKD systems using a weak coherent state source and
decoy states. Specifically, by implementing a linear-optics
unambiguous-state-discrimination measurement, we show that the security of a
system without phase randomization --- which is a step assumed in conventional
security analyses but sometimes neglected in practice --- can be compromised.
We conclude that implementing phase randomization is essential to the security
of decoy-state QKD systems under current security analyses.Comment: 12 pages, 5 figure
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