278 research outputs found
Hyperbolic inverse mean curvature flow
summary:We prove the short-time existence of the hyperbolic inverse (mean) curvature flow (with or without the specified forcing term) under the assumption that the initial compact smooth hypersurface of () is mean convex and star-shaped. Several interesting examples and some hyperbolic evolution equations for geometric quantities of the evolving hypersurfaces are shown. Besides, under different assumptions for the initial velocity, we can get the expansion and the convergence results of a hyperbolic inverse mean curvature flow in the plane , whose evolving curves move normally
Part2Word: Learning Joint Embedding of Point Clouds and Text by Matching Parts to Words
It is important to learn joint embedding for 3D shapes and text in different
shape understanding tasks, such as shape-text matching, retrieval, and shape
captioning. Current multi-view based methods learn a mapping from multiple
rendered views to text. However, these methods can not analyze 3D shapes well
due to the self-occlusion and limitation of learning manifolds. To resolve this
issue, we propose a method to learn joint embedding of point clouds and text by
matching parts from shapes to words from sentences in a common space.
Specifically, we first learn segmentation prior to segment point clouds into
parts. Then, we map parts and words into an optimized space, where the parts
and words can be matched with each other. In the optimized space, we represent
a part by aggregating features of all points within the part, while
representing each word with its context information, where we train our network
to minimize the triplet ranking loss. Moreover, we also introduce cross-modal
attention to capture the relationship of part-word in this matching procedure,
which enhances joint embedding learning. Our experimental results outperform
the state-of-the-art in multi-modal retrieval under the widely used benchmark
Effect of fish meal replacement by Chlorella meal with dietary cellulase addition on growth performance, digestive enzymatic activities, histology and myogenic genes' expression for crucian carp Carassius auratus
This study was conducted to investigate the effects of fish meal (FM) replacement by Chlorella meal (CM) with dietary cellulase supplementation on growth performance, digestive enzymatic activities, histology and myogenic genes' expression in crucian carp Carassius auratus (initial body weight: 2.90 +/- 0.02 g, mean +/- SEM). Six isonitrogenous diets were formulated at two cellulase levels (0 and 2 g kg(-1)). At each cellulase level, CM was added at three levels of 0, 533.1 and 710.8 g kg(-1) to substitute 0, 75 and 100% of dietary FM respectively. Each experimental diet was randomly assigned to triplicate groups with 25 juvenile fish per fibreglass tank for 8 weeks. Dietary CM substitution significantly increased growth, feed utilization, amylase activity and the expression of Myod, Mrf4 and Myf5, but reduced the Myog expression. Dietary cellulase addition increased hepatosomatic and viscerosomatic index, lipase activity and the expression of Mrf4, but reduced trypsin activity and the expression of Myog and Myf5. Dietary CM substitution enlarged the cell size and also caused some karyopyknosis in liver. Our results showed that CM could totally replace FM in diets; dietary cellulase supplementation at the level of 2 g kg(-1) played a subtle role in improving growth and feed utilization for crucian carp.</p
Systematic Assessment of the Effect of Internal Library in Targeted Analysis of SWATH-MS.
Targeted analysis of sequential window acquisition of all theoretical mass spectra (SWATH-MS) requires the spectral library, which can be generated by shotgun mass spectrometry (MS) or by the pseudo-spectra files directly obtained from SWATH-MS data. The external library generated by shotgun MS is employed in most SWATH-MS research. However, performance of the internal library, which is constructed by pseudo-spectra files, in the targeted analysis of SWATH-MS has not been systemically evaluated. Here, we show that up to 40% of the peptides detected by the internal library were not overlapped with those detected by the external library for most SWATH-MS data sets. However, the internal library did not identify extra phosphopeptides compared with the external library for phosphoproteomic SWATH-MS data. Therefore, the internal library should be incorporated into the external library for targeted analysis of nonphosphoproteomic SWATH-MS, given that it can significantly increase the number of peptides of SWATH-MS without requiring additional instrument measurement time
A novel fluorescence “on–off–on” chemosensor for Hg²⁺ via a water-assistant blocking heavy atom effect
Upper rim pyrene-functionalized hexahomotrioxacalix[3]arene L was synthesized via Click chemistry, and its fluorescence behaviors toward several common metal cations were investigated. L exhibited a significant fluorescence quenching response to Hg²⁺ in CH₃CN solution, which was unaffected by the coexistence of other competitive metal cations. Thus, L can be utilized as a highly selective and sensitive fluorescent chemosensor for Hg²⁺ with a detection limit in the nM level. Interestingly, the quenched fluorescence emission can be successfully revived upon the addition of water. In this process, the heavy atom effect of Hg²⁺ can be blocked by further coordination of a water molecule and resulted in the revival of the fluorescence emission of L/Hg²⁺ complex. Particularly, other polar solvents such as CH₃OH and CH₃CH₂OH also have the ability to revive the fluorescence emission of the L/Hg²⁺ complex, but on a much smaller scale than observed for H₂O. The heavy atom effect and blocking thereof were demonstrated within the same system by the use of a C₃-symmetric homooxacalix[3]arene scaffold. The present studies provided further evidence for the blocking heavy atom effect
Click synthesis of a quinoline-functionalized hexahomotrioxacalix[3]arene : a turn-on fluorescence chemosensor for Fe³⁺
A novel quinoline-functionalized hexahomotrioxacalix[3]arene L was synthesized via Click chemistry and its chemosensing properties with various metal ions were investigated. The chemosensor L exhibited a high selectivity for Fe³⁺ with little interference from other environmentally and biologically relevant metal ions, leading to a prominent ‘off-on’ type fluorescent signalling behaviour. Our studies demonstrated that the detection limit on fluorescence response of the sensor to Fe³⁺+ is in the 10⁻⁷ M range. The mechanism of the interaction between the L and Fe³⁺ has been investigated in detail by ¹H NMR spectroscopic titration experiments
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