Pre-Segmented Down-Sampling Accelerates Graph Neural Network-Based 3D Object Detection in Autonomous Driving.

Graph neural networks (GNNs) have been proven to be an ideal approach to deal with irregular point clouds, but involve massive computations for searching neighboring points in the graph, which limits their application in large-scale LiDAR point cloud processing. Down-sampling is a straightforward and indispensable step in current GNN-based 3D detectors to reduce the computational burden of the model, but the commonly used down-sampling methods cannot distinguish the categories of the LiDAR points, which leads to an inability to effectively improve the computational efficiency of the GNN models without affecting their detection accuracy. In this paper, we propose (1) a LiDAR point cloud pre-segmented down-sampling (PSD) method that can selectively reduce background points while preserving the foreground object points during the process, greatly improving the computational efficiency of the model without affecting its 3D detection accuracy. (2) A lightweight GNN-based 3D detector that can extract point features and detect objects from the raw down-sampled LiDAR point cloud directly without any pre-transformation. We test the proposed model on the KITTI 3D Object Detection Benchmark, and the results demonstrate its effectiveness and efficiency for autonomous driving 3D object detection.

Elbow Kinematics and Function Following Treatment with Open Arthrolysis and Hinged External Fixator.

OBJECTIVE: Open arthrolysis (OA) combined with hinged external fixator (HEF) is a promising surgical option for patients with elbow stiffness. This study aimed to investigate elbow kinematics and function following a combined treatment with OA and HEF in elbow stiffness cases. METHODS: Patients treated with OA with or without HEF due to elbow stiffness were recruited between August 2017 and July 2019. Elbow flexion-extension motion and function (Mayo elbow performance scores, MEPS) were recorded and compared between patients with and without HEF during a 1-year follow-up period. Additionally, those with HEF were assessed by dual fluoroscopy at week 6 postoperatively. Flexion-extension and varus-valgus motions, as well as ligament insertion distances of the anterior medial collateral ligament (AMCL) and lateral ulnar collateral ligament (LUCL), were compared between the surgical and intact sides. RESULTS: This study included 42 patients, of which 12 with HEF demonstrated a similar flexion-extension angle and range of motion (ROM) and MEPS as the other patients. In patients with HEF, the surgical elbows showed limitations in flexion-extension (maximal flexion, 120.5° ± 5.3° vs 140.4° ± 6.8°; maximal extension, 13.1° ± 6.0° vs 6.4° ± 3.0°; ROM, 107.4° ± 9.9° vs 134.0° ± 6.8°; all Ps < 0.01) compared with the contralateral sides. During elbow flexion, a gradual valgus-to-varus transition of the ulna, increase in the AMCL insertion distance, and steady change in the LUCL insertion distance were observed, with no significant differences between the bilateral sides. CONCLUSIONS: Patients treated with OA and HEF demonstrated similar elbow flexion-extension motion and function to those treated with OA alone. Although the use of HEF could not restore an intact flexion-extension ROM and might result in some minor but not significant changes in kinematics, it contributed to clinical outcomes comparable to that of the treatment with OA alone.

Stenotic intercondylar notch is not a risk factor for posterior cruciate ligament rupture: a morphological analyses using magnetic resonance imaging.

PURPOSE: The present study aimed to examine the factors related to the morphological characteristics of the femoral condyle in posterior cruciate ligament rupture in female and male populations. METHODS: One hundred and three patients (41 females, 62 males) with posterior cruciate ligament rupture from 2010 to 2020 were included in this retrospective case-control study. The sex and age of the posterior cruciate ligament rupture group were matched to those of the control group (41 females, 62 males; age range 16-69 years). Magnetic resonance imaging was used to measure the intercondylar notch width, femoral condylar width, and intercondylar notch angle in both the axial and coronal images. The 'α' angle was also measured using magnetic resonance imaging. The notch width index is the ratio of the intercondylar notch width to the femoral condylar width. Three types of intercondylar notch shapes (types A, U, and W) were evaluated in the axial magnetic resonance imaging images. RESULTS: The difference in the mean coronal notch width index between the study groups was statistically significant in the female population. The difference in the mean coronal femoral condylar width between the study groups was statistically significant in the male population. CONCLUSIONS: A larger coronal notch width index was the greatest risk factor for posterior cruciate ligament rupture in the female population. In the male population, decreased coronal condylar width was the greatest risk factor for posterior cruciate ligament rupture. The results did not indicate that patients with a PCL rupture have a stenotic intercondylar notch. Posterior cruciate ligament injury prevention strategies could be applied to females with a larger coronal notch width index and males with a decreased condylar width. LEVELS OF EVIDENCE: Level III.

PI3K/Akt pathway expression in children with different obesity degrees and its relationship with glucolipid metabolism and insulin resistance.

OBJECTIVE: This study investigated and analyzed the expression of PI3K/Akt pathway in children with different degree of obesity and its connection with glucolipid metabolism and insulin resistance (IR). METHODS: 157 children with simple obesity, who admitted to our hospital from March 2020 to September 2020, were enrolled as obesity group. These children were divided into mild-group (n=67), moderate-group (n=55) and severe-group (n=35) referring to their body mass index (BMI). Another 60 healthy children admitted to hospitalized were randomly chosen as control group. The expression of PI3K mRNA and Akt mRNA in peripheral blood mononuclear cells (PBMCs) of each group were detected by RT-PCR, and its connection with glucose and lipid metabolism, as well as IR was analyzed. RESULTS: Each group of children had insignificant difference in FBG (Fasting blood glucose) level (P>0.05). The triglyceride (TG), total cholesterol (TC), Low-density lipoprotein (LDL), Fasting insulin (FINS) and Homeostasis model assessment insulin resistance (HOMA-IR) levels in each obesity group were substantially higher than those in control group (P<0.05), and these levels decreased remarkably with the increase of obesity severity (P<0.05). The high-density lipoprotein (HDL) level of children in each obesity group was notably lower than that of the control group (P<0.05), and the level decreased remarkably with the ascending degree of obesity (P<0.05). The levels of PI3K mRNA and Akt mRNA in PBMCs of children in each obesity group were obviously lower than those in control group (P<0.05), and these index levels decreased much with the increasing worsen of children's obesity degree (P<0.05). The relative expression of PI3K mRNA and Akt mRNA in children with simple obesity was negatively correlated with TG, TC, LDL, FINS and HOMA-IR (P<0.05), positively correlated with HDL (P<0.05), and was not associated with FBG level (P>0.05). CONCLUSION: The inhibition of PI3K/Akt signaling pathway in children with simple obesity is associated with the abnormal glucolipid metabolism and IR, which affects the occurrence and progression of obesity.

Dual fluoroscopic imaging and CT-based finite element modelling to estimate forces and stresses of grafts in anatomical single-bundle ACL reconstruction with different femoral tunnels.

PURPOSE: Little is known about the in vivo forces and stresses on grafts used in anterior cruciate ligament (ACL) reconstruction. The aims of this study were to evaluate and compare the forces and stresses on grafts used in anatomical single-bundle ACL reconstruction at different locations of the femoral footprint (anterior vs middle vs posterior; high vs middle vs low) during a lunge motion. METHODS: Establish subject-specific finite element models with different graft's tunnel loci to represent the primary ACL reconstructions. A displacement controlled finite element method was used to simulate lunge motions (full extension to ~ 100° of flexion) with six-degree-of-freedom knee kinematics data obtained from the validated dual fluoroscopic imaging techniques. The reaction force of the femur and maximal principal stresses of the grafts were subsequently calculated during knee flexion. RESULTS: Increased and decreased graft forces were observed when the grafts were located higher and lower on the femoral footprint, respectively; anterior and posterior graft placement did not significantly affect the graft force. Lower and posterior graft placement resulted in less stress on the graft at higher degrees of flexion; there were no significant differences in stress when the grafts were placed from 0° to 30° of flexion on the femoral footprint. CONCLUSION: The proposed method is able to simulate knee joint motion based on in vivo kinematics. The results demonstrate that posterior to the centre of the femoral footprint is the strategic location for graft placement, and this placement results in anatomical graft behaviour with a low stress state.

Lack of Potential Pharmacokinetic and Pharmacodynamic Interactions Between Piragliatin, a Glucokinase Activator, and Simvastatin in Patients With Type 2 Diabetes Mellitus.

To evaluate the potential pharmacokinetic (PK) and pharmacodynamic (PD, glucose-lowering effect) interaction between simvastatin and piragliatin, both CYP3A substrates, 30 patients with type 2 diabetes mellitus participated in this open-label, randomized, 6-sequence, 3-way crossover (William's design) study. During 3 periods, patients were randomized to receive a single dose of 80 mg simvastatin alone, a single dose of 100 mg piragliatin alone, as well as single doses of 80 mg simvastatin and 100 mg piragliatin together. Primary PK and PD parameters were AUCs on dosing days. The ratio of geometric means (90% confidence intervals) of the AUCinf of piragliatin coadministered with simvastatin compared with piragliatin alone was 0.98 (0.92-1.05), whereas that of the AUCinf of simvastatin acid (active metabolite) coadministered with piragliatin compared with simvastatin alone, was 1.02 (0.90-1.16), suggesting lack of pharmacokinetic interaction between piragliatin and simvastatin. Piragliatin's glucose-lowering effect was not affected by coadministration of simvastatin. Overall, administration of piragliatin with simvastatin was without additional clinically relevant adverse effects as well as abnormality in laboratory tests, vital signs, and electrocardiogram parameters. Concomitant administration of simvastatin and piragliatin, both CYP3A substrates, has no clinically relevant effect on the pharmacokinetics of either piragliatin or simvastatin or on the pharmacodynamics for piragliatin.

Exploratory effects of a strong CYP3A inhibitor (ketoconazole), a strong CYP3A inducer (rifampicin), and concomitant ethanol on piragliatin pharmacokinetics and pharmacodynamics in type 2 diabetic patients.

Piragliatin is a CYP3A substrate; its inactive metabolite M4, formed through cytosolic reductase, is reversibly metabolized back to piragliatin through CYP3A. The impact of concomitant CYP3A modifiers thus cannot be predicted. Drinking alcohol under fasting conditions is associated with a recognized glucose-lowering effect, which might be synergistic with piragliatin's hypoglycemic effect. Two exploratory studies were conducted to examine these potential interactions in type 2 diabetes (T2D) patients: 16 completed an open-label, sequential 2-way crossover, 2-arm (randomized to ketoconazole and rifampicin) CYP3A study; another 18 participated in a double-blind, placebo-controlled, randomized 3-way crossover ethanol study. Administration of piragliatin (100-mg single dose) resulted in a 32% Cmax and 44% area under the curve (AUC∞ ) increase in piragliatin exposure without affecting glucose AUC0-6h following ketoconazole (400 mg QD × 5 days); 30% Cmax and 72% AUC∞ decrease in piragliatin exposure with a 13% increase in glucose AUC0-6h following rifampicin (600 mg QD × 5 days); and, unexpectedly, a 32% Cmax and 23% AUC0-6h decrease (no change in AUC∞ ) in piragliatin exposure with a 13% increase in glucose AUC0-6h following alcohol (40-g single dose). In conclusion, a strong CYP3A modifier or concomitant alcohol could lead to a change in exposure to piragliatin with a potential alteration in glucose-lowering effect.