34 research outputs found
Screening and identification of the dominant antigens of the African swine fever virus
African swine fever is a highly lethal contagious disease of pigs for which there is no vaccine. Its causative agent African swine fever virus (ASFV) is a highly complex enveloped DNA virus encoding more than 150 open reading frames. The antigenicity of ASFV is still unclear at present. In this study, 35 proteins of ASFV were expressed by Escherichia coli, and ELISA was developed for the detection of antibodies against these proteins. p30, p54, and p22 were presented as the major antigens of ASFV, positively reacting with all five clinical ASFV-positive pig sera, and 10 pig sera experimentally infected by ASFV. Five proteins (pB475L, pC129R, pE199L, pE184L, and pK145R) reacted well with ASFV-positive sera. The p30 induced a rapid and strong antibody immune response during ASFV infection. These results will promote the development of subunit vaccines and serum diagnostic methods against ASFV
Large expert-curated database for benchmarking document similarity detection in biomedical literature search
Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
Different femoral tunnel placement in posterior cruciate ligament reconstruction: a finite element analysis
Abstract Background At present, there is no consensus on the optimal biomechanical method for Posterior cruciate ligament (PCL) reconstruction, and the “critical corner” that is produced by the femoral tunnel is currently considered to be one of the main reasons for PCL failure. Thus, the purpose of this study was to identify one or several different tunnels of the femur, thereby reducing the influence of the "critical corner" without reducing the posterior stability of the knee. Methods CT and MRI data of the knee joint of a healthy adult man were collected, and computer-related software was used to reconstruct the finite element model of the knee joint, to provide different properties to different materials and to allow for the performance of a finite element analysis of the reconstructed model. The position of the femoral tunnel was positioned and partitioned according to anatomical posture, and three areas were divided (the antero-proximal region, the antero-distal region and the posterior region). In addition, we applied a posterior tibial load of 134 N to the reconstructed model, recorded and compared different tunnels of the femur, conducted peak stress at the flexion of the knee joint of 0°, 30°, 60° and 90°, and elicited the displacement of the proximal tibia. Results Among the 20 different femoral tunnels, the graft peak stress was lower in tunnels 4, 12 and 18 than in the PCL anatomical footpath tunnel 13, especially at high flexion angles (60° and 90°). These three tunnels did not increase the posterior displacement of the proximal tibia compared with the anatomical footpath tunnel 13. Conclusion In summary, among the options for PCL reconstruction of the femoral tunnel, the tunnels located 5 mm distal to the footprint and 5 mm anterior to the footprint could reduce the peak stress of the graft; additionally, it may reduce the "critical corner" and was shown to not reduce the posterior stability of the knee joint
Two Novel Measurements for the Drive-Mode Resonant Frequency of a Micromachined Vibratory Gyroscope
To investigate the drive-mode resonance frequency of a micromachined vibratory gyroscope (MVG), one needs to measure it accurately and efficiently. The conventional approach to measure the resonant frequency is by performing a sweep frequency test and spectrum analysis. The method is time-consuming and inconvenient because of the requirements of many test points, a lot of data storage and off-line analyses. In this paper, we propose two novel measurement methods, the search method and track method, respectively. The former is based on the magnitude-frequency characteristics of the drive mode, utilizing a one-dimensional search technique. The latter is based on the phase-frequency characteristics, applying a feedback control loop. Their performances in precision, noise resistivity and efficiency are analyzed through detailed simulations. A test system is implemented based on a field programmable gate array (FPGA) and experiments are carried out. By comparing with the common approach, feasibility and superiorities of the proposed methods are validated. In particular, significant efficiency improvements are achieved whereby the conventional frequency method consumes nearly 5,000 s to finish a measurement, while only 5 s is needed for the track method and 1 s for the search method
Taxonomy of Buellia epigaea-group (Caliciales, Caliciaceae), revealing a new species and two new records from China
During the Second Tibetan Plateau Scientific Expedition and Research Program, we discovered that white terricolous lichenized fungal species of Buellia De Not. were widely distributed across the Tibetan Plateau. After examining their morphology, chemistry and phylogeny, we describe Buellia alpina Xin Y. Wang & Li S. Wang, sp. nov. as new to science. It is present in alpine meadows, and is characterized by its effigurate thallus, distinct linear marginal lobes, cover of thick white pruina and four-spored asci. This is also the first report of Buellia elegans Poelt and Buellia epigaea (Pers.) Tuck from China. The Buellia epigaea-group has previously been characterized by white and often effigurate thalli that occur mainly on soil. However, our results show that species in this group actually belong to two distinct clades. This conclusion is based on analyses of the nuITS region and the combined regions dataset (nuITS-nuLSU-mtSSU-β-tubulin). We discuss differences in morphology, anatomy, chemistry and ecology among the putative Buellia epigaea-group. Detailed descriptions and figures for the three species from China and a key for species of Buellia epigaea-group are provided
A New Transient Frequency Acceptability Margin Based on the Frequency Trajectory
When the electric power system is disturbed, the transient frequency deviation may be large and harmful to its stable operation, especially in some small power systems. However, there is a lack of transient frequency acceptability margin (TFAM) which could be directly used by dispatchers. In this paper, a new TFAM is proposed based on the transient frequency acceptability index (TFAI). First, based on the frequency trajectory and the philosophy of “different weights to the different frequency offset levels„, a new TFAI is proposed combined with frequency thresholds and time duration limits. The effectiveness of the TFAI is verified, and the critical acceptable disturbance is determined by using the TFAI. Then, a new TFAM is proposed based on the critical acceptability disturbance. The proposed TFAM can quantitatively describe the distance of the operation point from the critical frequency acceptability point, and distinguish the transient frequency acceptability of different disturbances. Finally, with different simulations, the effectiveness and applicability of the proposed TFAM are verified. The TFAM can be used for disturbances with single-parameter and multiple parameters
Rediscovery of Five <i>Rinodina</i> Species Originally Described from Southwest China and One New Species
Rinodina is a lichenized fungal genus belonging to the Physciaceae, with c. 300 species worldwide. Nearly a century ago, Zahlbruckner described five species of the genus Rinodina from Southwest China. The type collections were the only records for these species. In the present study, new records for four of these species: Rinodina cornutula, R. globulans, R. handelii, and R. setschwana, and a recently described species, R. pluriloculata, are documented based on specimens collected from the holotype localities. Furthermore, one new species was discovered: Rinodina hengduanensis, characterized by areolate to subsquamulose thallus, jigsaw-like areoles, lecanorine apothecium, and Dirinaria-type ascospores. Rinodina setschwana is transferred to the genus Buellia based on its morphology, chemistry, and phylogeny and proposed as Buellia setschwana. We provide detailed morphological descriptions, pictures, and molecular phylogenetic analyses
A Resilient Method for Visual–Inertial Fusion Based on Covariance Tuning
To improve localization and pose precision of visual–inertial simultaneous localization and mapping (viSLAM) in complex scenarios, it is necessary to tune the weights of the visual and inertial inputs during sensor fusion. To this end, we propose a resilient viSLAM algorithm based on covariance tuning. During back-end optimization of the viSLAM process, the unit-weight root-mean-square error (RMSE) of the visual reprojection and IMU preintegration in each optimization is computed to construct a covariance tuning function, producing a new covariance matrix. This is used to perform another round of nonlinear optimization, effectively improving pose and localization precision without closed-loop detection. In the validation experiment, our algorithm outperformed the OKVIS, R-VIO, and VINS-Mono open-source viSLAM frameworks in pose and localization precision on the EuRoc dataset, at all difficulty levels
Squamarina (lichenised fungi) species described from China belong to at least three unrelated genera
Volume: 66Start Page: 135-15
Dynamics of hydrocarbon accumulation in the west section of the northern margin of the Qaidam Basin, NW China
Studies were conducted on the dynamic processes of hydrocarbon migration and accumulation in the west part of the northern margin of the Qaidam Basin, based on previous studies on basin evolution and hydrocarbon system. Based on the dynamics of petroleum accumulation, basin analysis and the numerical stimulation method were applied to reconstruct the basin evolution. Simulation analysis of petroleum accumulation in the main reservoir-forming stages were conducted in the light of source rock properties in different stages, fluid potential field and seepage property distribution of carrier beds. Controlling factors of reservoir formation in the northern margin of the Qaidam Basin were summarized. Studies showed that the Miocene is the main period of oil generation for the Jurassic source rocks in the studied area. The oil generation and migration volume were large. However, Saishiteng Sag was just on the slope in the northern part of Yiliping Sag. Structural traps were distributed at the margin of the basin. There was abundant oil migration to the north margin and a dissipation of the oil there during the later strong tectonic activities. During the late reservoir formation stage after the Pliocene, the source rocks generated mainly gas and not oil, and structural traps were well developed and provided good conditions for the natural gas reservoir formation. Deep structural traps in the basins were conducive to the formation of a large-scale low-permeability gas reservoir. Key words: northern margin of Qaidam Basin, petroleum accumulation dynamics, basin evolution, carrier bed, fluid potential, migration pathwa