Learning Signed Hyper Surfaces for Oriented Point Cloud Normal Estimation.

We propose a novel method called SHS-Net for point cloud normal estimation by learning signed hyper surfaces, which can accurately predict normals with global consistent orientation from various point clouds. Almost all existing methods estimate oriented normals through a two-stage pipeline, i.e., unoriented normal estimation and normal orientation, and each step is implemented by a separate algorithm. However, previous methods are sensitive to parameter settings, resulting in poor results from point clouds with noise, density variations and complex geometries. In this work, we introduce signed hyper surfaces (SHS), which are parameterized by multi-layer perceptron (MLP) layers, to learn to estimate oriented normals from point clouds in an end-to-end manner. The signed hyper surfaces are implicitly learned in a high-dimensional feature space where the local and global information is aggregated. Specifically, we introduce a patch encoding module and a shape encoding module to encode a 3D point cloud into a local latent code and a global latent code, respectively. Then, an attention-weighted normal prediction module is proposed as a decoder, which takes the local and global latent codes as input to predict oriented normals. Experimental results show that our algorithm outperforms the state-of-the-art methods in both unoriented and oriented normal estimation.

A novel encoder-decoder model based on Autoformer for air quality index prediction.

Rapid economic development has led to increasingly serious air quality problems. Accurate air quality prediction can provide technical support for air pollution prevention and treatment. In this paper, we proposed a novel encoder-decoder model named as Enhanced Autoformer (EnAutoformer) to improve the air quality index (AQI) prediction. In this model, (a) The enhanced cross-correlation (ECC) is proposed for extracting the temporal dependencies in AQI time series; (b) Combining the ECC with the cross-stage feature fusion mechanism of CSPDenseNet, the core module CSP_ECC is proposed for improving the computational efficiency of the EnAutoformer. (c) The time series decomposition and dilated causal convolution added in the decoder module are exploited to extract the finer-grained features from the original AQI data and improve the performance of the proposed model for long-term prediction. The real-world air quality datasets collected from Lanzhou are used to validate the performance of our prediction model. The experimental results show that our EnAutoformer model can greatly improve the prediction accuracy compared to the baselines and can be used as a promising alternative for complex air quality prediction.

Efficient Visible-Light-Driven Photocatalytic Hydrogen Generation over 2D/2D Co-ZIF-9/Ti3 C2 Hybrids.

Exploring precious-metal-free catalysts for efficient photocatalytic H2 evolution is highly desirable but still challenging. Herein, a novel 2D/2D Co-ZIF-9/Ti3 C2 composite was fabricated by a facile electrostatic self-assembly strategy. Owing to higher flux of photogenerated electron-holes and lower rate of recombination, the resultant composite exhibited better photocatalytic H2 evolution compared to Co-ZIF-9. When the content of Ti3 C2 was 2.5 wt %, a maximum photocatalytic H2 -generation rate of 3538.5 µmol g-1 ⋅ h-1 was achieved, which is 9.6 times that of bare Co-ZIF-9. Moreover, the Co-ZIF-9/Ti3 C2 composite displayed high photocatalytic stability. This study demonstrated for the first time the great potential of Co-ZIF-9/Ti3 C2 as a noble-metal-free catalyst for photocatalytic H2 generation.

The complete chloroplast genome of Rhododendron datiandingense (Ericaceae).

Rhododendron datiandingense is newly reported and endemic to China. The genome of R. datiandingense is 207,311 bp in length, including a large single-copy region of 190,689 bp and a small single-copy region of 2582 bp, a pair of inverted repeat regions (IRA) of 7020 bp each. The genome encodes 110 genes, comprising 77 protein-coding genes, four ribosomal RNA genes, and 29 transfer RNA genes. Repeat analysis revealed 62 simple sequence repeats (SSRs) in the genome. Phylogenetic analysis revealed that R. datiandingense is clearly separated from the other Rhododendron species and shown in the basal position.

[Clinical and pathological characteristics and surgical treatment of carotid body tumor with endocrine activity].

OBJECTIVE: To investigate the clinical and pathological characteristics and surgical treatment of carotid body tumor with endocrine activity (CBT). METHODS: Records of seven CBT patients with endocrine activity (Jan, 1991-Aug, 2011) who underwent surgical excision of tumor were retrospectively reviewed. The operations were performed with the careful peroperative preparation on the control of blood pressure, serum potassium and catecholamine. All the tumors were studied with the methods of HE staining, immunohistochemistry of chromogranin A (CgA) and S-100. RESULTS: All the operations were successfully accomplished and the patients recovered quickly. It was confirmed with pathological examination that all the tumors were CBT, coming from paraganglioma. Tumor cells and sertoli cells were found in HE staining, and all were positive of CgA and S-100. All patients were followed up for 12-60 months and no recurrence was found during the follow up. CONCLUSION: CBT with endocrine activity presents with identifiable clinical and pathological characteristics. The recommended treatment is surgical resection, careful perioperative preparation and care is important to avoid the severe complication due to the endocrine activity of tumor.

A comparison between the treatments of functional and nonfunctional carotid body tumors.

BACKGROUND: It is well known that carotid body tumors (CBTs) are rare and almost nonfunctional, and that functional CBTs are even less frequently seen, with or without catecholamine-induced symptoms. Objective of this study is to make comparison between the treatment effects on functional and nonfunctional CBTs. METHODS: The medical records of 46 patients (16 men and 30 women) of our unit who underwent surgical intervention for CBTs were retrospectively reviewed from January 2005 to July 2010. Patients were divided into two groups by function: group A (n = 5, functional CBTs) and group B (n = 41, nonfunctional CBTs). Perioperative and postoperative details were compared accordingly. RESULTS: All the patients successfully underwent tumor resection. Although symptoms were nonspecific, intraoperative hypertension (5/5, 100%) and persistent postoperative hypotension (3/5, 60%) were found in group A. No statistical difference was found in perioperative details and complications between two groups. No recurrence occurred in two groups during the follow-up period for a mean of 35.3 months (with a range of 12-60 months). CONCLUSION: Surgical resection is safe and effective even if the CBT is functional. Besides routine preparation, preoperative measurement of serum catecholamine, treatment with α- and ß-adrenergic blockade and gentle manipulation during operation are necessary.