2,134 research outputs found
A fault-tolerant triple-redundant voice coil motor for direct drive valves: Design, optimization, and experiment
AbstractA direct drive actuator (DDA) with direct drive valves (DDVs) as the control device is an ideal solution for a flight actuation system. This paper presents a novel triple-redundant voice coil motor (TRVCM) used for redundant DDVs. The TRVCM features electrical/mechanical hybrid triple-redundancy by securing three stators along with three moving coils in the same frame. A permanent magnet (PM) Halbach array is employed in each redundant VCM to simplify the system structure. A back-to-back design between neighborly redundancies is adopted to decouple the magnetic flux linkage. The particle swarm optimization (PSO) method is implemented to optimize design parameters based on the analytical magnetic circuit model. The optimization objective function is defined as the acceleration capacity of the motor to achieve high dynamic performance. The optimal geometric parameters are verified with 3D magnetic field finite element analysis (FEA). A research prototype has been developed for experimental purpose. The experimental results of magnetic field density and force output show that the proposed TRVCM has great potential of applications in DDA systems
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OMMA enables population-scale analysis of complex genomic features and phylogenomic relationships from nanochannel-based optical maps.
BackgroundOptical mapping is an emerging technology that complements sequencing-based methods in genome analysis. It is widely used in improving genome assemblies and detecting structural variations by providing information over much longer (up to 1 Mb) reads. Current standards in optical mapping analysis involve assembling optical maps into contigs and aligning them to a reference, which is limited to pairwise comparison and becomes bias-prone when analyzing multiple samples.FindingsWe present a new method, OMMA, that extends optical mapping to the study of complex genomic features by simultaneously interrogating optical maps across many samples in a reference-independent manner. OMMA captures and characterizes complex genomic features, e.g., multiple haplotypes, copy number variations, and subtelomeric structures when applied to 154 human samples across the 26 populations sequenced in the 1000 Genomes Project. For small genomes such as pathogenic bacteria, OMMA accurately reconstructs the phylogenomic relationships and identifies functional elements across 21 Acinetobacter baumannii strains.ConclusionsWith the increasing data throughput of optical mapping system, the use of this technology in comparative genome analysis across many samples will become feasible. OMMA is a timely solution that can address such computational need. The OMMA software is available at https://github.com/TF-Chan-Lab/OMTools
Establish real-time monitoring models of cotton aphid quantity based on different leaf positions in cotton seedlings
Cotton aphids, Aphis gossypii glover, are major pest threats to cotton plants, leading to quality and yield loss of cotton. Rapid and accurate evaluation on the occurrence and quantity of cotton aphids can help precision management and treatment of cotton aphids. The occurrence rules of cotton aphids on different leaf positions in cotton seedling stage for two cultivars of cotton were studied. The quantity of cotton aphids in the whole cotton seedlings were predicted based on the single leaf cotton aphid quantity. The correlation analysis results showed that cotton aphids of single leaf were significantly and positively correlated with the infected time, the all leaves of the whole plant, the whole plant contained all leaves and branches. The variance analysis results showed that cotton aphids of single leaf were significant difference with the extension of infected time. Based on different leaf positions, monitoring models were constructed respectively. The modelling set’s determination coefficient of ‘Xinluzao-45’ was greater than 0.8, while ‘Lumainyan-24’ was greater than 0.6. The best monitoring leaf position was the third for ‘Xinluzao-45’, the sixth for ‘Lumianyan-24’. From the data analysis, we can realize that it is feasible to construct a monitoring model based on the occurrence of cotton aphid in one leaf in cotton seedling, and different cotton varieties have different leaf positions. This will greatly reduce the investment of manpower and time
Intranasal Immunization with Chitosan/pCAGGS-flaA Nanoparticles Inhibits Campylobacter jejuni in a White Leghorn Model
Campylobacter jejuni is the most common zoonotic bacterium associated with human diarrhea, and chickens are considered to be one of the most important sources for human infection, with no effective prophylactic treatment available. We describe here a prophylactic strategy using chitosan-DNA intranasal immunization to induce specific immune responses. The chitosan used for intranasal administration is a natural mucus absorption enhancer, which results in transgenic DNA expression in chicken nasopharynx. Chickens immunized with chitosan-DNA nanoparticles, which carried a gene for the major structural protein FlaA, produced significantly increased levels of serum anti-Campylobacter jejuni IgG and intestinal mucosal antibody (IgA), compared to those treated with chitosan-DNA (pCAGGS). Chitosan-pCAGGS-flaA intranasal immunization induced reductions of bacterial expellation by 2-3 log10 and 2 log10 in large intestine and cecum of chickens, respectively, when administered with the isolated C. jejuni strain. This study demonstrated that intranasal delivery of chitosan-DNA vaccine successfully induced effective immune response and might be a promising vaccine candidate against C. jejuni infection
The negative interplay between Aurora A/B and BRCA1/2 controls cancer cell growth and tumorigenesis via distinct regulation of cell cycle progression, cytokinesis, and tetraploidy
It is well known that the activation of Aurora A/B (Aur A/B) or inactivation of BRCA1/2 induces tumor formation. Others and we have reported that the mutual suppression between Aur A/B and BRCA1/2 may manipulate cancer cell growth and tumorigenesis, however, the interactive regulation and mechanism between these molecules are still elusive. In this study, by consecutive silencing of Aur A/B or/and BRCA1/2 with specific shRNAs, we showed that, in BRCA2-deficient pancreatic cancer cell line Capan-1 and in ovarian cancer cell line OVCA433, Aur A/B and BRCA1/2 inversely regulated the expression of each other likely through proteasome-mediated proteolysis but not through gene transcription. Aur A/B and BRCA1/2 conversely regulated cell cycle progression mainly through control of p53 and cyclin A. Moreover, the disruption of Aur A/B blocked abnormal cytokinesis and decreased cell multinuclearity and chromosome tetraploidy, whereas the deprivation of BRCA1/2 promoted the abnormal cytokinesis and enhanced the cell multinuclearity and tetraploidy. Furthermore, we showed by animal assays that the depletion of Aur A/B inhibited tumor growth of both cell lines, while the knockdown of BRCA1/2 promoted the tumor growth. However, the concurrent silencing of Aur A/B and BRCA1/2 diminished the effects of these molecules on the regulation of cell cycle, cytokinesis, and tetraploidy, leading to the burdened tumor sizes similar to those induced by scrambled shRNA-treated control cells. In summary, our study revealed that the negative interplay between Aur A/B and BRCA1/2 inversely controls the cell proliferation, cell cycle progression, cell multinuclearity, and tetraploidization to modulate tumorigenesis
Simple Cholecystectomy Is Adequate for Patients With T1b Gallbladder Adenocarcinoma < 1 cm in Diameter
Purpose: Consensus-based clinical guidelines recommend that simple cholecystectomy (SC) is adequate for T1a gallbladder adenocarcinoma (GBA), but extended cholecystectomy (EC), SC plus lymphatic dissection, should be considered for T1b and more advanced GBA. Whether lymphatic dissection is necessary for the treatment of T1b GBA remains controversial. This study attempts to better define the current criteria for local treatment of T1b GBA, by examining the relationship between lymph node (LN) metastasis and tumor size in such patients.Patients and methods: Clinical data from patients with T1b GBA receiving curative surgical treatment between 2004 and 2015 were collected from the Surveillance, Epidemiology, and End Results (SEER) database. Baseline characteristics for the entire cohort were described, and overall survival (OS) and cancer-specific survival (CSS) were analyzed with the Kaplan–Meier method.Results: In total, 277 patients were enrolled for further analysis; 127 underwent lymphadenectomy. Among them, 23 patients had tumors <1 cm in diameter, none of which had LN metastasis; 104 patients had tumors ≥1 cm, 15 of which had positive LNs. In the group with tumor size <1 cm, there was no significant survival difference between treatment with SC or EC (P = 0.694). A clinical benefit was observed in T1b GBA patients with a tumor size ≥1 cm receiving EC vs. those receiving SC (P = 0.012).Conclusion: SC was adequate for treatment of T1b GBA < 1 cm in diameter. This evidence may be included as part of current guidelines
Nitrate Removal Characteristics of Nitrate-reducing Bacteria Pseudomonas sp. XS-18 at Low Carbon-to-nitrogen Ratio
Low carbon-to-nitrogen (C/N) ratios are the main characteristic of domestic wastewater. In this study, we evaluated the nitrate removal characteristics of Pseudomonas sp. XS-18 at low C/N ratios (4.0 and 6.0) and pH 11.0. We also analyzed the causes of the nitrate removal at low C/N ratios in this strain. At pH 11.0 and a C/N ratio of 4.0, the strain was effective in removing nitrate. Additionally, the total organic carbon content decreased over time at low C/N ratios, requiring more energy to complete vital activities. Furthermore, low C/N conditions resulted in less strain secretion compared to high C/N settings, and the polysaccharide content degraded more quickly than protein over time. To provide a carbon source for the nitrate reduction process, strains with low C/N ratio and high pH secreted more soluble microbial by-products. This strain is able to metabolize its own secreted extracellular polymeric substances as a carbon source to enhance nitrate removal
Fatal Interstitial Lung Disease after Addition of Sorafenib to a Patient with Lung Adenocarcinoma Who Had Failed to Improve with Erlotinib Alone
A comparative study of virus nucleic acid re-positive and non-re-positive patients infected with SARS-CoV-2 Delta variant strain in the Ningxia Hui Autonomous Region
ObjectiveThis study aimed to provide a basis for epidemic prevention and control measures as well as the management of re-positive personnel by analyzing and summarizing the characteristics of re-positive patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta variant infections discharged from a hospital in the Ningxia Hui Autonomous Region in 2021.MethodsThis case-control study included a total of 45 patients with Delta variant infections diagnosed in the Fourth People's Hospital of the Ningxia Hui Autonomous Region between October 17 and November 28, 2021. Based on the nucleic acid test results post-discharge, the patients were dichotomized into re-positive and non-re-positive groups. Based on the time of the first re-positive test, the re-positive group was further divided into <7 and ≥7 days groups to compare their clinical characteristics and explore the possible influencing factors of this re-positivity.ResultsOf the 45 total patients, 16 were re-positive (re-positivity rate: 35.6%), including four patients who were re-positive after 2 weeks (re-positivity rate: 8.8%). The median time of the first re-positive after discharge was 7 days (IQR: 14-3). The re-positive group was younger than the non-re-positive group (35 vs. 53, P < 0.05), had a higher proportion of patients who were not receiving antiviral therapy (56.2 vs. 17.2%, P < 0.05). The median CT value of nucleic acid in the re-positive group was considerably greater than that at admission (36.7 vs. 22.6 P < 0.05). The findings demonstrated that neutralizing antibody treatment significantly raised the average IgG antibody level in patients, particularly in those who had not received COVID-19 vaccine (P < 0.05). The median lowest nucleic acid CT value of the ≥7 days group during the re-positive period and the immunoglobulin G (IgG) antibody level at discharge were lower than those in the <7 days group (P < 0.05). When compared to the non-positive group, patients in the ≥7 days group had a higher median virus nucleic acid CT value (27.1 vs. 19.2, P < 0.05) and absolute number of lymphocytes at admission (1,360 vs. 952, P < 0.05), and a lower IgG antibody level at discharge (P < 0.05).ConclusionsIn conclusion, this study found that: (1) The re-positivity rate of SARS-CoV-2 Delta variant infection in this group was 35.6%, while the re-positivity rate was the same as that of the original strain 2 weeks after discharge (8.0%). (2) Young people, patients who did not use antiviral therapy or had low IgG antibody levels at discharge were more likely to have re-positive. And the CT value of nucleic acid at the time of initial infection was higher in re-positive group. We speculated that the higher the CT value of nucleic acid at the time of initial infection, the longer the intermittent shedding time of the virus. (3) Re-positive patients were asymptomatic. The median CT value of nucleic acid was > 35 at the re-positive time, and the close contacts were not detected as positive. The overall transmission risk of re-positive patients is low
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