219 research outputs found
Lateral response and energetics of cable-guided hoisting system with time-varying length
The lateral response, energetics and stability of the cable-guided hoisting system that differs from the rail-guided, such as elevator systems, is investigated in this paper. While the equations of motion are established by Hamilton's principle, the boundary conditions are obtained to calculate the natural frequencies with the modified velocity of wave propagation. Then, the governing equation is transformed into a set of ordinary differential equations through the Galerkin method and the rate of change in the energy is derived from the control volume viewpoint. The system frequencies, response of each order and energy characteristics are analyzed. The results show that the system frequencies first decrease, and then increase with the increase of the length and demonstrate that the modified velocity of wave propagation is reasonable by comparison of three approaches. The presented method proves to be effective to obtain the response of each order. According to Lyapunov’s second method, the rate of change in the energy indicates the cable-guided hoisting system experiences stability and instability during downward and upward movements, respectively
Vegetation dynamics of abandoned paddy fields and surrounding wetlands in the lower Tumen River Basin, Northeast China
On the temperate lowland plain of the lower Tumen River, agricultural development has converted most marshland into paddy fields. However, the locations of old paddy fields in the lowland temperate zone, where the vegetation structure is dominated by herbs adapted to seasonally wet or waterlogged conditions, are poorly known, and the impact of land use history on marshland diversity and shifts in plant functional groups has been scantly researched. In this study, we used a chronosequence approach to investigate herbaceous wetland communities in different recovery phases (15 years), as well as natural wetland as a reference. We assessed their ecological characteristics, species composition and diversity to determine how they change during natural succession. Plant species composition and dominance in the abandoned fields changed markedly during natural secondary succession. Initially, the annual weeds Echinochloa crus-galli and Bidens tripartita were dominant. Later, communities gradually became dominated first by Polygonum thunbergii and then by tussock-forming Carex rostrata. Species diversity was higher in abandoned fields than in natural wetlands and decreased with time. The partition of β-diversity components revealed that replacement was the prominent process structuring plant communities in paddy field at different times since abandonment. Our results suggest that the vegetation of abandoned paddy fields could be restored effectively through natural succession, although there were some differences in plant functional group traits. Abandoned paddy fields may be good sites for restoration of wetland species and conservation of wetland habitat
Galaxy Morphology Classification Using Multi-Scale Convolution Capsule Network
The classification of galaxy morphology is a hot issue in astronomical
research. Although significant progress has been made in the last decade in
classifying galaxy morphology using deep learning technology, there are still
some deficiencies in spatial feature representation and classification
accuracy. In this study, we present a multi-scale convolutional capsule network
(MSCCN) model for the classification of galaxy morphology. First, this model
improves the convolutional layers through using a multi-branch structure to
extract multi-scale hidden features of galaxy images. In order to further
explore the hidden information in the features, the multi-scale features are
encapsulated and fed into the capsule layer. Second, we use a sigmoid function
to replace the softmax function in dynamic routing, which can enhance the
robustness of MSCCN. Finally, the classification model achieving 97% accuracy,
96% precision, 98% recall, and 97% F1-score under macroscopic averaging. In
addition, a more comprehensive model evaluation were accomplished in this
study. We visualized the morphological features for the part of sample set,
which using the t-distributed stochastic neighbor embedding (t-SNE) algorithm.
The results shows that the model has the better generalization ability and
robustness, it can be effectively used in the galaxy morphological
classification
Lateral and torsional vibrations of cable-guided hoisting system with eccentric load
Theoretical investigation of the lateral and torsional vibrations of the hoisting cage in the cable-guided hoisting system caused by the eccentric load and the flexibility of the guiding cable is presented in this paper. The assumed modes method (AMM) is adopted to discretize the hoisting cable and two guiding cables, then Lagrange equations of the first kind are used to derive the equations of motion, while the geometric relationships between the hoisting cage and the cables are accounted for by the Lagrangian multiplier. Considering all the geometric matching conditions are approximately linear, the differential algebraic equations (DAEs) are transformed to the ordinary differential equations (ODEs). The dynamic responses of the hoisting cage are calculated, and especially the lateral displacements of the guiding cable and the constraints forces at the interfaces are obtained. Preload plays a vital role in affecting the cage vibration, thus, the effects of the total preload and the tension difference are analyzed. The numerical results indicate increasing the total preload can decrease the vibration displacements, while the tension difference has little impact on the vibration but can obviously change the constraint forces. In addition, the vibration displacements are directly proportional to the eccentric load, but less sensitive to the hoisting mass
Clusterin confers gmcitabine resistance in pancreatic cancer
<p>Abstract</p> <p>Objective</p> <p>To measure clusterin expression in pancreatic cancer tissues and cell lines and to evaluate whether clusterin confers resistance to gmcitabine in pancreatic cancer cells.</p> <p>Methods</p> <p>Immunohistochemistry for clusterin was performed on 50 primary pancreatic cancer tissues and 25 matched backgrounds, and clusterin expression in 5 pancreatic cancer cell lines was quantified by Western blot and PT-PCR. The correlation between clusterin expression level and gmcitabine IC50 in pancreatic cancer cell lines was evaluated. The effect of an antisense oligonucleotide (ASO) against clusterin(OGX-011) on gmcitabine resistance was evaluated by MTT assays. Xenograft model was used to demonstrate tumor growth.</p> <p>Results</p> <p>Pancreatic cancer tissues expressed significantly higher levels of clusterin than did normal pancreatic tissues (<it>P </it>< 0.01). Clusterin expression levels were correlated with gmcitabine resistance in pancreatic cancer cell lines, and OGX-011 significantly decreased BxPc-3 cells resistance to gmcitabine (<it>P </it>< 0.01). <it>In vivo </it>systemic administration of AS clusterin and gmcitabine significantly decreased the s.c. BxPC-3 tumor volume compared with mismatch control ODN plus gmcitabine.</p> <p>Conclusion</p> <p>Our finding that clusterin expression was significantly higher in pancreatic cancer than in normal pancreatic tissues suggests that clusterin may confer gmcitabine resistance in pancreatic cancer cells.</p
The intestinal γδ T cells: functions in the gut and in the distant organs
Located in the frontline against the largest population of microbiota, the intestinal mucosa of mammals has evolved to become an effective immune system. γδ T cells, a unique T cell subpopulation, are rare in circulation blood and lymphoid tissues, but rich in the intestinal mucosa, particularly in the epithelium. Via rapid production of cytokines and growth factors, intestinal γδ T cells are key contributors to epithelial homeostasis and immune surveillance of infection. Intriguingly, recent studies have revealed that the intestinal γδ T cells may play novel exciting functions ranging from epithelial plasticity and remodeling in response to carbohydrate diets to the recovery of ischemic stroke. In this review article, we update regulatory molecules newly defined in lymphopoiesis of the intestinal γδ T cells and their novel functions locally in the intestinal mucosa, such as epithelial remodeling, and distantly in pathological setting, e.g., ischemic brain injury repair, psychosocial stress responses, and fracture repair. The challenges and potential revenues in intestinal γδ T cell studies are discussed
A novel endophytic fungus strain of Cladosporium: its identification, genomic analysis, and effects on plant growth
IntroductionEndophytic microorganisms are bacteria or fungi that inhabit plant internal tissues contributing to various biological processes of plants. Some endophytic microbes can promote plant growth, which are known as plant growth-promoting endophytes (PGPEs). There has been an increasing interest in isolation and identification of PGPEs for sustainable production of crops. This study was undertaken to isolate PGPEs from roots of a halophytic species Sesuvium portulacastrum L. and elucidate potential mechanisms underlying the plant growth promoting effect.MethodsSurface-disinfected seeds of S. portulacastrum were germinated on an in vitro culture medium, and roots of some germinated seedlings were contaminated by bacteria and fungi. From the contamination, an endophytic fungus called BF-F (a fungal strain isolated from bacterial and fungal contamination) was isolated and identified. The genome of BF-F strain was sequenced, its genome structure and function were analyzed using various bioinformatics software. Additionally, the effect of BF-F on plant growth promotion were investigated by gene cluster analyses.ResultsBased on the sequence homology (99%) and phylogenetic analysis, BF-F is likely a new Cladosporium angulosum strain or possibly a new Cladosporium species that is most homologous to C. angulosum. The BF-F significantly promoted the growth of dicot S. portulacastrum and Arabidopsis as well as monocot rice. Whole genome analysis revealed that the BF-F genome has 29,444,740 bp in size with 6,426 annotated genes, including gene clusters associated with the tryptophan synthesis and metabolism pathway, sterol synthesis pathway, and nitrogen metabolism pathway. BF-F produced indole-3-acetic acid (IAA) and also induced the expression of plant N uptake related genes.DiscussionOur results suggest that BF-F is a novel strain of Cladosporium and has potential to be a microbial fertilizer for sustainable production of crop plants. The resulting genomic information will facilitate further investigation of its genetic evolution and its function, particularly mechanisms underlying plant growth promotion
Test methods to determine durability of concrete under combined environmental actions and mechanical load: final report of RILEM TC 246-TDC
At present several methods are available to predict the durability of reinforced concrete structures. In most cases, one dominant deterioration process such as carbonation or chloride penetration is taken into consideration. Experimental results as well as observations in practice show that this is not a realistic and certainly not a conservative approach. In order to test more realistically, RILEM TC 246-TDC, founded in 2011, has developed a method to determine the durability of concrete exposed to the combined action of chloride penetration and mechanical load. In this report, a test method is presented which allows determination of realistic diffusion coefficients for chloride ions in concrete under compressive or tensile stress. Comparative test results from five different laboratories showed that the combination of mechanical and environmental loads may be much more severe than a single environmental load without mechanical loading. Modelling and probabilistic analysis also showed that the obvious synergetic effects cannot be neglected in realistic service life prediction
Variasi Temperatur Pencampuran Terhadap Parameter Marshall Pada Campuran Lapis Aspal Beton
This study was conducted to determine the effect of temperature variations on the mixing processof the asphalt concrete AC-WC (Asphalt Concrete-Wearing Course) subtle gradations in themiddle limit and lower limit of the Marshall parameters with reference to specifications of BinaMarga, 2010.From the results of experiments conducted that the optimum asphalt content is used to middle limitusing a asphalt content of 5,7% and 6,8% for the lower limit after that mixing was done usingtemperature variation of 120 o C, 130 o C, 140 o C, 150 o C, and 160 o C.To a mixture of Laston AC-WC subtle gradations middle limit grading 5,7% asphalt contentmixing temperature using a temperature of 120 o C, 130 o C, 140 o C, 150 o C, 160 o C and still meet allstandards of marshall parameters. Ideal mixing temperature variations in the middle limit ofmixing temperature 150 o C-160 o C. While the lower limit to the level of 6,8% asphalt contentmixing temperatures between 120 o C-160 o C did not meet the specifications, because the MQ valuebelow the minimum value of 250 kg / mm
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Association of increased Treg and Th17 with pathogenesis of moyamoya disease
Immuno-inflammation has been shown to play a pivotal role in the pathogenesis of moyamoya disease (MMD). However, how did circulating Treg/Th17 cells involve in MMD patients remains unclear. 26 MMD, 21 atherothrombotic stroke, and 32 healthy controls were enrolled in this study. MMD patients have a significantly higher percentage of circulating Treg and Th17 cells as well as their dominantly secreting cytokines than other groups (P < 0.0001), whereas no difference was found in the ratio of Treg/Th17 between patients in MMD and atherothrombotic stroke group or control subjects (P = 0.244). However, the increased Treg in MMD patients which were enriched with FrIII Treg cells had deficient suppressive functions (P = 0.0017) compared to healthy volunteers. There was a positive correlation between Treg or TGF-β and MMD Suzuki’s stage. And the level of circulating Treg was as an independent factor associated with MMD stage. Besides, TGF-β was also correlated with the increased expression of VEGF in MMD patients. Our findings indicated an important involvement of circulating Treg in the pathogenic development of MMD and TGF-β in Treg induced VEGF
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