A Small-Object-Detection Algorithm Based on LiDAR Point-Cloud Clustering for Autonomous Vehicles.

3D object-detection based on LiDAR point clouds can help driverless vehicles detect obstacles. However, the existing point-cloud-based object-detection methods are generally ineffective in detecting small objects such as pedestrians and cyclists. Therefore, a small-object-detection algorithm based on clustering is proposed. Firstly, a new segmented ground-point clouds segmentation algorithm is proposed, which filters out the object point clouds according to the heuristic rules and realizes the ground segmentation by multi-region plane-fitting. Then, the small-object point cloud is clustered using an improved DBSCAN clustering algorithm. The K-means++ algorithm for pre-clustering is used, the neighborhood radius is adaptively adjusted according to the distance, and the core point search method of the original algorithm is improved. Finally, the detection of small objects is completed using the directional wraparound box model. After extensive experiments, it was shown that the precision and recall of our proposed ground-segmentation algorithm reached 91.86% and 92.70%, respectively, and the improved DBSCAN clustering algorithm improved the recall of pedestrians and cyclists by 15.89% and 9.50%, respectively. In addition, visualization experiments confirmed that our proposed small-object-detection algorithm based on the point-cloud clustering method can realize the accurate detection of small objects.

Machine learning algorithm to predict postoperative bleeding complications after lateral decubitus percutaneous nephrolithotomy.

Bleeding is a serious complication following percutaneous nephrolithotomy (PCNL). This study establishes a predictive model based on machine learning algorithms to forecast the occurrence of postoperative bleeding complications in patients with renal and upper ureteral stones undergoing lateral decubitus PCNL. We retrospectively collected data from 356 patients with renal stones and upper ureteral stones who underwent lateral decubitus PCNL in the Department of Urology at Peking University First Hospital-Miyun Hospital, between January 2015 and August 2022. Among them, 290 patients had complete baseline data. The data was randomly divided into a training group (n = 232) and a test group (n = 58) in an 8:2 ratio. Predictive models were constructed using Logistic Regression, Random Forest, and Extreme Gradient Boosting (XGBoost). The performance of each model was evaluated using Accuracy, Precision, F1-Score, Receiver Operating Characteristic curves, and Area Under the Curve (AUC). Among the 290 patients, 35 (12.07%) experienced postoperative bleeding complications after lateral decubitus PCNL. Using postoperative bleeding as the outcome, the Logistic model achieved an accuracy of 73.2%, AUC of 0.605, and F1 score of 0.732. The Random Forest model achieved an accuracy of 74.5%, AUC of 0.679, and F1 score of 0.732. The XGBoost model achieved an accuracy of 68.3%, AUC of 0.513, and F1 score of 0.644. The predictive model for postoperative bleeding after lateral decubitus PCNL, established based on machine learning algorithms, is reasonably accurate. It can be utilized to predict postoperative stone residue and recurrence, aiding urologists in making appropriate treatment decisions.

Experimental Investigation of Seismic Performance of Precast Concrete Wall-Beam-Slab Joints with Overlapping U-Bar Loop Connections.

In the era of energy conservation and environmental protection, as well as the industrialization of buildings, precast concrete (PC) structures have been developed and increasingly applied in construction industries due to their advantages of outstanding workability and ecofriendliness. In order to verify the reliability of overlapping U-bar loop connections and a modified form of these connections, and study the seismic performance of PC wall-beam-slab joints with these connection methods, three full-scale wall-beam-slab joints were designed and tested under low reversed cyclic loading, including one cast-in-place (CIP) specimen and two PC specimens. Based on the test results, the seismic performance of the PC joints was studied by comparing their damage process, hysteretic loops and skeleton curves, load-carrying capacity, ductility, equivalent stiffness, and energy dissipation with those of the CIP joint. After analyzing the experimental results, the following conclusions can be drawn: the overlapping U-bar loop connection and its modified form are effective and reasonable; the specimen with the modified connection form showed slightly better mechanical properties; the failure mode of the PC joints was consistent with that of the CIP joint; and the generation, distribution, and development of cracks in the PC specimens were similar to those in the CIP specimen. In addition, the stiffness of the PC joints was similar to that of the CIP joint, and the load-carrying capacity, ductility, and energy dissipation of the PC joints were better than those of the CIP joint. Moreover, the research in this paper can also provide some guidance for assembling wall-beam-slab joints in PC shear wall structures.

Effect of endovascular treatment on high-risk patients with chronic carotid artery occlusion.

OBJECTIVE: This study aims to discuss the safety and short-term efficacy of endovascular treatment on high-risk patients with chronic carotid artery occlusion. METHODS: A retrospective analysis was performed on the clinical data of 16 high-risk patients with chronic carotid artery occlusion who received endovascular treatment at the Department of Neurosurgery of the First Affiliated Hospital of Xinjiang Medical University from November 2013 to July 2016. The incidence of adverse events at 1 week, 30 days and six months post-operation were observed, and NIHSS was adopted to assess the neurological function of patients six months before and after the operation. Follow-up time was 6-26 months, with an average of 18.4 months. RESULTS: The degree of carotid artery stenosis of these 16 patients was 100%. The degree of which after the operation was 24.9 ± 17.0%; and the difference was statistically significant (P<0.05). Iatrogenic carotid artery dissection occurred in one case, and persistent hypotension and sinus bradycardia occurred in one case. Furthermore, one case of endovascular treatment was not approved to be opened. Afterwards, temporal artery-STA-MCA bypass was performed; upon postoperative head CTA and DSA, the result showed that the perfusion was good. One case refused to undergo surgical treatment. The NHSS score of 14 cases of endovascular treatment that were successfully opened six months after the operation was 2.0 ± 1.36, which improved (P<0.05) compared with that of pre-operation. CONCLUSION: Endovascular treatment on high-risk patients with chronic carotid artery occlusion is safe and effective. And it has obvious curative effect in short mid-term. KEY WORDS: Arterial occlusive disease, Carotid artery, Endovascular treatment, Treatment outcome.

Fifteen novel immunoreactive proteins of Chinese virulent Haemophilus parasuis serotype 5 verified by an immunoproteomic assay.

Haemophilus parasuis (H. parasuis) is associated with meningitis, polyserositis, polyarthritis and bacterial pneumonia. At present, its prevention and control is difficult because of the lack of suitable subunit vaccines. Nowadays, high-throughput methods, immunoproteomics, are available to screen for more vaccine candidates. A protein extraction method for H. parasuis and two-dimensional electrophoresis (2-DE) were optimized to provide high-resolution profiles covering pH 3 to 10. Twenty immunoreactive spots were excised from gels after strict comparison between 2-DE Western blot membranes and the relevant gels. Matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) and MALDI-TOF-TOF-MS successfully identified 16 different proteins. Fifteen of them were reported as immunoreactive proteins in H. parasuis for the first time. In addition, recombinant HP5-7 (ABC transporter, periplasmic-binding protein) showed immunoreactivity both with hyperimmune rabbit serum and convalescent swine serum. Four recombinants of the 14 successfully expressed genes showed immunoreactivity with hyperimmune rabbit serum.

Endovascular embolization of large and giant intracranial aneurysms of long-term angiographic fol-low-up / 中国神经精神疾病杂志

Objective To investigate the outcome of endovascular treatment of large or giant intracranial aneu?rysm by long-term angiographic follow-up. Methods Clinical data of 72 patients with large or giant intracranial aneu?rysms receiving endovascular treatment were analyzed retrospectively. Thirty aneurysms were treated with coil emboliza?tion alone, 14 with stent-assisted coiling, 15 with covered stent-deployment and 13 with parent artery occlusion. Results complete occlusion was achieved in 10 cases of pure coil embolization, 7 cases of stent assisted coil embolization,11 cas?es of completely covered stent-deployment and,13 cases of parent artery occlusion. The postoperative immediate com?plete embolism rate was 56.9%. Nearly completely occlusion was achieved in 17 cases of pure coil embolization, in 6 cas?es of stent auxiliary coil embolization, 4 cases of covered stent-deloyment and zero case of parent artery occlusion. The total postoperative immediate nearly completely embolism rate was 37.5%. Incomplete occlusion was achieved in 3 cases of pure coil thrombosis, 1 case of stent assisted coil, zero case of ,covered stent-deloyment and zero case of parent artery occlusion. The total immediate postoperative incomplete embolization rate was 5.6%. Patients were followed up for 6 to 72 months, with an average follow-up of 24.2 months . All patients had no bleeding. The total periprocedural complica?tion rate was 9.7%and there were no death cases. The recurrence of aneurysm in pure spring coil embolization treatment was higher compared with other treatments. The overall recurrence rate was 23.6%. The recurrent 14 aneurysms were suc?cessfully treated endovascularly. Conclusions Endovascular embolization treatment of intracranial large or giant aneu?rysm is safe and effective but its long-term recurrence rate is high. Thus a close follow-up is needed. Endovascular inter?ventional therapy based on the location of aneurysm and shape characteristics can improve treatment effectiveness and re?duce recurrence rate.

Chaperonin GroEL: a novel phylogenetically conserved protein with strong immunoreactivity of Avian Pathogenic Escherichia coli isolates from duck identified by immunoproteomics.

Avian Pathogenic Escherichia coli (APEC) is one of the most important bacterial pathogens of poultry. The lack of suitable vaccines and the emergence of multi-resistant strains have hampered the control of avian colibacillosis. To identify immunogenic proteins of APEC as vaccine candidates, immunoproteomics and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) were applied. Proteins from total cell lysates of APEC DE205B isolated from the brain of a duck with septicemia and neurological symptom in China were separated by two-dimensional electrophoresis (2-DE) and reacted with hyperimmune duck serum against DE205B. Fourteen immunoreactive spots were found, representing 11 distinct proteins. These included two predominant immunogenic components, outer membrane protein A (OmpA) and flagellin (FliC). GroEL, which is a member of the molecular chaperone family and identical structurally to eukaryotic heat shock protein 60 (Hsp60), and the other eight antigens are reported here as immunoreactive proteins of APEC for the first time. Subsequently, nine genes encoding the identified proteins were successfully cloned and expressed in E. coli BL21 (DE3). Seven of the recombinant proteins were able to react with hyperimmune duck serum and three of them, GroEL, OmpA and FliC, showed stronger immunoreactivity. Challenge studies revealed that, just like OmpA and FliC, recombinant GroEL stimulated a strong antibody response and supported protective efficacy against APEC infection in ducks. With high phylogenetic conservation, it is considered that GroEL would be an ideal immunogen of APEC for vaccine development.

Immunoproteomics selection of cross-protective vaccine candidates from Riemerella anatipestifer serotypes 1 and 2.

Riemerella anatipestifer (RA) is one of the most important bacterial pathogens of ducks and other avian species worldwide. Current approaches for controlling RA are hindered by the absence of effective vaccines, particularly cross-protective vaccines. In this present study, an immunoproteomics approach was used to identify cross-protective vaccine candidates against RA serotype 1 strain RAf63 and serotype 2 strain RAf153. First, whole-cell and secreted proteins of RAf153 and RAf63 were separated by two-dimensional gel electrophoresis. Then, western blotting of the proteome was performed using duck convalescent serum against RAf153, followed by matrix-assisted laser desorption/ionization time of flight mass spectrometry and peptide mass fingerprinting. Finally, common immunoreactive proteins from RAf153 and RAf63 were identified as cross-protective vaccine candidates, and so these were cloned and expressed recombinantly. The cross-protection abilities of purified recombinant protein vaccines were tested against homologous and heterologous virulent strains in a challenge model that followed vaccination. Six proteins were identified as cross-protective vaccine candidates. Three of these proteins showed reactivity with convalescent sera after prokaryotic expression, and the recombinant outer membrane protein A (OmpA) showed high protective indices against challenges with RAf153 (60%) and RAf63 (50%). In summary, we have developed a high-throughout, accurate, rapid and efficient method for the successful selection of cross-protective vaccine candidates.

Immunoproteomic identification of 11 novel immunoreactive proteins of Riemerella anatipestifer serotype 2.

Riemerella anatipestifer (RA) is one of the most important bacterial pathogens of ducks and other avian species worldwide. Twenty-one serotypes of RA have been identified, with RA serotype two (RA2) being reported as one of the most predominant serotypes underlying infections in China. Current approaches to the control of RA are hindered by the absence of effective vaccines, particularly those that exhibit cross-protection between different serotypes. In this study, a combination of two-dimensional electrophoresis, Western blot analysis and mass spectrometry were used to identify the antigenic proteins of RA2. A total of 16 immunoreactive proteins, representing 12 distinct proteins, were identified. These included OmpA, a known immunogenic protein of RA, as well as novel immunogens. PCR analysis also indicated that genes corresponding to each of the 12 distinct proteins were conserved among different RA serotypes. Eleven genes encoding these proteins were cloned and expressed in Escherichia coli BL21 (DE3). Eight of the 11 expressed proteins were able to react with hyperimmune rabbit serum against RAf153. One of these, recombinant elongation factor G, responded to RA2 sera but not RA1, whereas recombinant OmpA responded to both RA1 and RA2 sera. These data form a basis for the development of vaccine for both homologous and heterogeneous RA serotypes in addition to the production of target antigens for the development of diagnostic antibodies with the potential to distinguish between RA serotypes.

Immunoproteomic analysis of bacterial proteins of Actinobacillus pleuropneumoniae serotype 1.

BACKGROUND: Actinobacillus pleuropneumoniae (APP) is one of the most important swine pathogens worldwide. Identification and characterization of novel antigenic APP vaccine candidates are underway. In the present study, we use an immunoproteomic approach to identify APP protein antigens that may elicit an immune response in serotype 1 naturally infected swine and serotype 1 virulent strain S259-immunized rabbits. RESULTS: Proteins from total cell lysates of serotype 1 APP were separated by two-dimensional electrophoresis (2DE). Western blot analysis revealed 21 immunoreactive protein spots separated in the pH 4-7 range and 4 spots in the pH 7-11 range with the convalescent sera from swine; we found 5 immunoreactive protein spots that separated in the pH 4-7 range and 2 in the pH 7-11 range with hyperimmune sera from S259-immunized rabbits. The proteins included the known antigens ApxIIA, protective surface antigen D15, outer membrane proteins P5, subunit NqrA. The remaining antigens are being reported as immunoreactive proteins in APP for the first time, to our knowledge. CONCLUSIONS: We identified a total of 42 immunoreactive proteins of the APP serotype 1 virulent strain S259 which represented 32 different proteins, including some novel immunoreactive factors which could be researched as vaccine candidates.