199 research outputs found
An Aircraft Ranging Algorithm Based on Two Frames of Image in Monocular Image Sequence
We proposed a novel rotation-invariant feature based passive ranging algorithm to estimate the distance of an imaged non-cooperation target to camera. This improved algorithm avoids sometimes occurrence of physically unreasonable results in solving the existing quartic equation, such as the happening of complex or negative value. This method uses three matched points in two adjacent frames of an image sequence to extract depth-dependent line features of the target. With this line features combination of the observer’s displacement and imaging directions, a quadratic equation was build to estimate the distance. Analysis shows that the proposed new passive ranging equation would be solvable when the observer is with non-zero displacement in adjacent sampling instances. Our reduced-model experiment also demonstrates that the proposed algorithm is not only simple and feasible but also with a relative ranging error no more than 4 per cent in most cases.Defence Science Journal, Vol. 64, No. 1, January 2014, DOI:10.14429/dsj.64.288
Study on Multi-step Forming Paths for Double Curved Parts of 1561 Aluminium Alloy
Recently, corrosion-resistant 1561 aluminium alloy has been widely applied to the production of curved parts. However, the sheets of this material will generate a high amount of springback during multi-point forming, which means that a large amount of springback compensation is required. In this paper, four multi-step forming paths are designed to study the effect of forming paths on the multi-point forming results of double curved parts for 1561 aluminium alloy. Numerical simulation of the multi-step forming of curved sheets is carried out by ABAQUS finite element simulation software. The simulation results indicate that the 1561 aluminium alloy double curved parts produce poor situations such as wrinkling and low forming accuracy in single-step forming, while the accuracy improves significantly and the forming quality increases after four-step forming. Therefore, a four-step forming path was adopted for stamping tests on double curved parts. The results of the accuracy inspection of the formed parts by Gom-inspect demonstrate that the quality of the curved parts can be effectively improved by four-step forming, which has a certain significance in guiding the forming preparation of parts for engineering applications
Normal Red Blood Cell Count Reference Values in Chinese Presenile Women Given by Geographical Area
Background/PurposeWe aimed to standardize the normal reference value of red blood cell (RBC) counts in Chinese presenile women using an underlying scientific basis.MethodsThis research was conducted to study the relationship between the normal reference value of 31,405 RBC samples from presenile women in eight different geographical areas in China. RBC counts were determined using a microscopic counting method.ResultsThere was a significant correlation between geographical factors and the normal reference RBC value in presenile women (F = 187.82, p = 0.000). Using stepwise regression analysis, one regression equation was obtained.ConclusionIf geographical values are obtained in a certain area, the normal RBC reference value in presenile women in this area can be obtained using the regression equation
Hydrogen sulfide is involved in the chilling stress response in Vitis vinifera L.
Hydrogen sulfide (H2S) is an important signaling molecule involved in several stress-resistance processes in plants, such as drought and heavy metal stresses. However, little is known about the roles of H2S in responses to chilling stress. In this paper, we demonstrated that chilling stress enhance the H2S levels, the H2S synthetase (L-/D-cysteine desulfhydrase, L/DCD) activities, and the expression of L/DCD gene in Vitis vinifera L. ‘F-242’. Furthermore, the seedlings were treated with sodium hydrosulfide (NaHS, a H2S donor) and hypotaurine (HT, a H2S scavenger) at 4°C to examine the effects of exogenous H2S on grape. The results revealed that the high activity of superoxide dismutase and enhanced expression of VvICE1 and VvCBF3 genes, but low level of super oxide anion radical, malondialdehyde content and cell membrane permeability were detected after addition of NaHS. In contrast, HT treatment displayed contrary effect under the chilling temperature. Taken together, these data suggested that H2S might be directly involved in the cold signal transduction pathway of grape
Irreversible dual inhibitory mode: the novel Btk inhibitor PLS-123 demonstrates promising anti-tumor activity in human B-cell lymphoma.
The B-cell receptor (BCR) signaling pathway has gained significant attention as a therapeutic target in B-cell malignancies. Recently, several drugs that target the BCR signaling pathway, especially the Btk inhibitor ibrutinib, have demonstrated notable therapeutic effects in relapsed/refractory patients, which indicates that pharmacological inhibition of BCR pathway holds promise in B-cell lymphoma treatment. Here we present a novel covalent irreversible Btk inhibitor PLS-123 with more potent anti-proliferative activity compared with ibrutinib in multiple cellular and in vivo models through effective apoptosis induction and dual-action inhibitory mode of Btk activation. The phosphorylation of BCR downstream activating AKT/mTOR and MAPK signal pathways was also more significantly reduced after treatment with PLS-123 than ibrutinib. Gene expression profile analysis further suggested that the different selectivity profile of PLS-123 led to significant downregulation of oncogenic gene PTPN11 expression, which might also offer new opportunities beyond what ibrutinib has achieved. In addition, PLS-123 dose-dependently attenuated BCR- and chemokine-mediated lymphoma cell adhesion and migration. Taken together, Btk inhibitor PLS-123 suggested a new direction to pharmacologically modulate Btk function and develop novel therapeutic drug for B-cell lymphoma treatment
Eff ect of a comprehensive programme to provide universal access to care for sputum-smear-positive multidrugresistant tuberculosis in China: a before-and-after study
Background China has a quarter of all patients with multidrug-resistant tuberculosis (MDRTB) worldwide, but less
than 5% are in quality treatment programmes. In a before-and-after study we aimed to assess the eff ect of a
comprehensive programme to provide universal access to diagnosis, treatment, and follow-up for MDRTB in
four Chinese cities (population 18 million).
Methods We designated city-level hospitals in each city to diagnose and treat MDRTB. All patients with smear-positive
pulmonary tuberculosis diagnosed in Center for Disease Control (CDC) clinics and hospitals were tested for MDRTB
with molecular and conventional drug susceptibility tests. Patients were treated with a 24 month treatment package
for MDRTB based on WHO guidelines. Outpatients were referred to the CDC for directly observed therapy.
We capped total treatment package cost at US796 to $174), reducing the ratio of patients’ expenses
to annual household income from 17·6% to 3·5% (p<0·0001 for all comparisons between baseline and programme
periods). However, 36 (15%) patients did not start or had to discontinue treatment in the programme period because
of fi nancial diffi culties.
Interpretation This comprehensive programme substantially increased access to diagnosis, quality treatment, and
aff ordable treatment for MDRTB. The programme could help China to achieve universal access to MDRTB care but
greater fi nancial risk protection for patients is needed
Reticulation is a Risk Factor of Progressive Subpleural non-Fibrotic Interstitial Lung Abnormalities
Rationale: Interstitial lung abnormalities (ILAs) are being increasingly identified in clinical
practice. In particular for subpleural non-fibrotic ILAs, the risk of progression over time and
the risk factors for progressive behavior are still largely unknown.
Objectives: To determine the age band prevalence of ILAs and the risk of radiological
progression of subpleural non-fibrotic ILAs over time in a large health check-up population,
and to identify how reticulation contributes to the risk of radiological progression.
Methods: Based on ILAs definition by the Fleischner Society, low-dose chest CT images from
community-dwelling population undergone health check-up were evaluated for ILAs.
Multivariable logistic regression was used to assess the risk of radiological progression.
Measurements and Main Results: Among 155,539 individuals, 3,300 (2.1%) were confirmed
to have ILAs: the vast majority (81.7%) were defined as subpleural non-fibrotic ILAs. The
prevalence of ILAs increased linearly with age (P for trend<0.0001). Of 454 individuals with
subpleural non-fibrotic ILAs, 198 (43.6%) had radiological progression over 4 years. The
presence of reticulation on initial imaging was an independent predictor of radiological
progression (OR 1.9; 95%CI 1.2-3.0, P=0.0040). No difference in radiological progression was
identified between subpleural non-fibrotic ILAs with extensive reticulation and subpleural
fibrotic ILAs (73.0% vs. 68.8%, P=0.7626).
Conclusions: The prevalence of ILAs increases linearly with age. Nearly half of subpleural
non-fibrotic ILAs progress radiologically over 4 years. The presence of reticulation is a risk
factor for radiological progression. Subpleural non-fibrotic ILAs with extensive reticulation
are likely to be a feature of subpleural fibrotic ILAs
Gallnut tannic acid alleviates gut damage induced by Salmonella pullorum in broilers by enhancing barrier function and modulating microbiota
Pullorum disease (PD) is a bacterial infection caused by Salmonella pullorum (S. pullorum) that affects poultry. It is highly infectious and often fatal. Antibiotics are currently the mainstay of prophylactic and therapeutic treatments for PD, but their use can lead to the development of resistance in pathogenic bacteria and disruption of the host's intestinal flora. We added neomycin sulfate and different doses of tannic acid (TA) to the drinking water of chicks at 3 days of age and infected them with PD by intraperitoneal injection of S. pullorum at 9 days of age. We analyzed intestinal histopathological changes and the expression of immune-related genes and proteins by using the plate smear method, histological staining, real-time fluorescence quantitative PCR, ELISA kits, and 16S rRNA Analysis of intestinal flora. The results demonstrate that S. pullorum induces alterations in the immune status and impairs the functionality of the liver and intestinal barrier. We found that tannic acid significantly ameliorated S. pullorum-induced liver and intestinal damage, protected the intestinal physical and chemical barriers, restored the intestinal immune barrier function, and regulated the intestinal flora. Our results showed that TA has good anti-diarrhoeal, growth-promoting, immune-regulating, intestinal barrier-protecting and intestinal flora-balancing effects, and the best effect was achieved at an additive dose of 0.2%
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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