A coarse-to-fine point completion network with details compensation and structure enhancement.

Point cloud completion, the issue of estimating the complete geometry of objects from partially-scanned point cloud data, becomes a fundamental task in many 3d vision and robotics applications. To address the limitations on inadequate prediction of shape details for traditional methods, a novel coarse-to-fine point completion network (DCSE-PCN) is introduced in this work using the modules of local details compensation and shape structure enhancement for effective geometric learning. The coarse completion stage of our network consists of two branches-a shape structure recovery branch and a local details compensation branch, which can recover the overall shape of the underlying model and the shape details of incomplete point cloud through feature learning and hierarchical feature fusion. The fine completion stage of our network employs the structure enhancement module to reinforce the correlated shape structures of the coarse repaired shape (such as regular arrangement or symmetry), thus obtaining the completed geometric shape with finer-grained details. Extensive experimental results on ShapeNet dataset and ModelNet dataset validate the effectiveness of our completion network, which can recover the shape details of the underlying point cloud whilst maintaining its overall shape. Compared to the existing methods, our coarse-to-fine completion network has shown its competitive performance on both chamfer distance (CD) and earth mover distance (EMD) errors. Such as, the repairing results on the ShapeNet dataset of our completion network are reduced by an average of [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] in terms of CD error, comparing with PCN, FoldingNet, Atlas, and CRN methods, respectively; and also reduced by an average of [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] in terms of EMD error, respectively. Meanwhile, the completion results on the ModelNet dataset of our network have an average reduction of [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] in terms of CD error, comparing to PCN, FoldingNet, Atlas, and CRN methods, respectively; and also an average reduction of [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] in terms of EMD error, respectively. Our proposed point completion network is also robust to different degrees of data incompleteness and model noise.

A highly selective and easily acquisitive near-infrared fluorescent probe for detection and imaging of hydrogen sulfide in cells.

Hydrogen sulfide (H2S) plays a substantial role as a messenger in the physiological and pathological processes of many diseases. Recently, the fluorescence probe of H2S based on organic dye has attracted great attention. However, the emission of many probes is in the UV-vis region (400-600 nm), so it has the disadvantages of shallow tissue penetration and more vulnerable to spontaneous fluorescence interference. Although several H2S probes have been developed that emit more than 650 nm, there is a complex structure difficult to synthesize or unstable in storage. Aimed at simply structural and easily synthesized H2S fluorescent probes with emission wavelength more than 650 nm, a novel near-infrared (NIR) probe (NIR-H2S) here was rationally designed with 4-(2-carboxyphenyl)-7-(diethylamino)-2-(4-hydroxystyryl)chromenylium (NIR-OH) as a fluorescent dye and 2,4-dinitrophenyl moiety as a recognition group. Addition of H2S, the "turn-on" NIR fluorescence response at 736 nm of NIR-H2S was displayed, accompanied by a visual colour change from purple to green when excited at 686 nm. As an easily acquisitive H2S probe, NIR-H2S has been successfully applied to cell imaging for H2S detection with the advantages such as long fluorescence emission, low toxicity, high sensitivity and strong selectivity.

Comparative properties and functions of type 2 and type 4 pigeon cryptochromes.

Two types of vertebrate cryptochromes (Crys) are currently recognized. Type 2 Crys function in the molecular circadian clock as light-independent transcriptional repressors. Type 4 Crys are a newly discovered group with unknown function, although they are flavoproteins, and therefore, may function as photoreceptors. It has been postulated that Crys function in light-dependent magnetoreception, which is thought to contribute towards homing and migratory behaviors. Here we have cloned and annotated the full-length pigeon ClCry1, ClCry2, and ClCry4 genes, and characterized the full-length proteins and several site-directed mutants to investigate the roles of these proteins. ClCry1 and ClCry2 are phylogenetically grouped as Type 2 Crys and thus are expected to be core components of the pigeon circadian clock. Interestingly, we find that ClCry4 is properly annotated as a Type 4 Cry. It appears that many birds possess a Type 4 Cry which, as in pigeon, is misannotated. Like the Type 2 Crys, ClCry4 is widespread in pigeon tissues. However, unlike the Type 2 Crys, ClCry4 is cytosolic, and purified ClCry4 possesses FAD cofactor, which confers characteristic UV-Vis spectra as well as two photochemical activities. We find that ClCry4 undergoes light-dependent conformational change, which is a property of insect Type 1 Crys involved in the insect-specific pathway of photoentrainment of the biological clock. ClCry4 can also be photochemically reduced by a mechanism common to all FAD-containing Cry family members, and this mechanism is postulated to be influenced by the geomagnetic field. Thus pigeon Crys control circadian behavior and may also have photosensory function.

The antenna transcriptome changes in mosquito Anopheles sinensis, pre- and post- blood meal.

Antenna is the main chemosensory organ in mosquitoes. Characterization of the transcriptional changes after blood meal, especially those related to chemoreception, may help to explain mosquito blood sucking behavior and to identify novel targets for mosquito control. Anopheles sinensis is an Asiatic mosquito species which transmits malaria and lymphatic filariasis. However, studies on chemosensory biology in female An. sinensis are quite lacking. Here we report a transcriptome analysis of An. sinensis female antennae pre- and post- blood meal. We created six An. sinensis antenna RNA-seq libraries, three from females without blood meal and three from females five hours after a blood meal. Illumina sequencing was conducted to analyze the transcriptome differences between the two groups. In total, the sequenced fragments created 21,643 genes, 1,828 of them were novel. 12,861 of these genes were considered to be expressed (FPKM >1.0) in at least one of the two groups, with 12,159 genes expressed in both groups. 548 genes were differentially expressed in the blood-fed group, with 331 genes up-regulated and 217 genes down-regulated. GO enrichment analysis of the differentially expressed genes suggested that there were no statistically over represented GO terms among down-regulated genes in blood-fed mosquitoes, while the enriched GO terms of the up-regulated genes occurred mainly in metabolic process. For the chemosensory gene families, a subtle distinction in the expression levels can be observed according to our statistical analysis. However, the firstly comprehensive identification of these chemosensory gene families in An. sinensis antennae will help to characterize the precise function of these proteins in odor recognition in mosquitoes. This study provides a first global view in the changes of transcript accumulation elicited by blood meal in An. sinensis female antennae.