Classification guided thick fog removal network for drone imaging: ClassifyCycle.

The foggy images captured by drones are nonuniform due to inhomogeneous distribution of fog in higher altitude, leading to the obvious fog thickness differences in the images. This paper proposes a classification guided thick fog removal network for drone imaging, termed ClassifyCycle. The drone images are input into the proposed classification module (ICLFn) to enhance the reliability of follow-up learning network. The style migration module (ISMn) is introduced to reduce the image distortion, such as hue artifact and texture distort. The proposed network ClassifyCycle does not require paired foggy and corresponding fog-free datasets, avoiding the phenomena of overexposure, distortion, color deviation and fog residue after defogging. Extensive experimental results show that the proposed ClassifyCycle network surpasses the state-of-the-art algorithms on synthetic and realistic drone images captured in thick fog weather.

Influence of Obesity and Changes in Weight or BMI on Incident Fractures in Postmenopausal Women: From Peking Vertebral Fracture Study.

This study aims to investigate the influence of overweight/obesity and change in weight or body mass index (BMI) on incident fractures among Chinese postmenopausal women. According to BMI, 754 postmenopausal women were categorized into normal weight (NW), overweight (OW), and obesity (OB) groups, respectively. We used data from the baseline and the second survey for statistical analysis, including anthropometric data, clinical fractures, and morphometric vertebral fractures (MVFs) assessed by X-rays. The prevalence of previous MVFs was 32.7% and 21.8% in the OB and NW groups, respectively (p < 0.05). All incident fractures and incident MVFs accounted for 10.7 and 6.3% among all participants within five years. Overweight/obesity and increase in weight or BMI during the follow-up had no associations with all incident fractures, incident MVFs, and incident clinical non-VFs among all participants. However, after multivariate adjustment, the increased BMI at baseline was the risk factor of incident MVFs in the OW group (odds ratio, OR 2.06, 95% confidence interval, 95% CI 1.16-3.66, p = 0.014), and increase in weight (OR 0.89, 95% CI 0.79-0.99, p = 0.036) or BMI (OR 0.77, 95% CI 0.59-0.99, p = 0.045) during the follow-up were the protective factors of all incident fractures in the NW group. Overweight/obesity and change in weight or BMI do not correlate with fracture risk in postmenopausal women, but an increase in weight is the protective factor against incident fractures in normal-weight participants. Overweight postmenopausal women with a higher BMI should pay attention to the risk of MVFs.

Relationships between sclerostin and morphometric vertebral fractures, bone mineral density, and bone microarchitecture in postmenopausal women.

Higher sclerostin levels in postmenopausal women are associated with improved bone microarchitecture, areal and volumetric bone mineral density, and bone strength. However, the serum sclerostin level had no independent associations with the prevalence of morphometric vertebral fractures in this population after multivariable adjustment. PURPOSE: We aim to investigate the associations between serum sclerostin levels and morphometric vertebral fractures (VFs) prevalence, bone mineral density (BMD), and bone microarchitecture in postmenopausal women. METHODS: A total of 274 community-dwelling postmenopausal women were randomized enrolled. We collected general information and measured the serum sclerostin level. Morphometric VFs were assessed on the lateral thoracic and lumbar spine X-rays. Areal BMD and calculated trabecular bone score (TBS) were detected by dual-energy X-ray absorptiometry, and volumetric BMD and bone microarchitecture data were acquired from high-resolution peripheral quantitative computed tomography. RESULTS: The prevalence of morphometric VFs was 18.6% in the cohort, and it was significantly higher in the lowest quartile of the sclerostin group than that in the highest quartile of the sclerostin group (27.9% vs. 11.8%, p<0.05). But the serum sclerostin had no independent association with the prevalence of morphometric VFs after adjusting by age, body mass index, BMD at the lumbar vertebrae 1-4, and fragility fracture history after 50 years old (odds ratio: 0.995, 95% confidence interval: 0.987-1.003, p=0.239). The serum sclerostin level positively correlated with the areal, volumetric BMDs, and TBS. It also had significant positive associations with Tb.BV/TV, Tb.N, Tb.Th, and Ct.Th, and negative associations with Tb.Sp and Tb.1/N.SD. CONCLUSION: Chinese postmenopausal women with higher serum sclerostin levels had a lower prevalence of morphometric VFs, higher BMDs, and better bone microarchitecture. Nevertheless, the serum sclerostin level had no independent association with the prevalence of morphometric VFs.

Serum Irisin level is associated with fall risk, muscle strength, and cortical porosity in postmenopausal women.

Background: Irisin plays a role in bone-muscle crosstalk, but the relationship between the serum irisin level and bone microarchitecture remains unknown. Objective: This study aimed to investigate the relationships between serum irisin level and fall risk, muscle strength, bone mineral density (BMD), and bone microarchitecture among Chinese postmenopausal women. Methods: In all 138 postmenopausal women, handgrip strength, short physical performance battery (SPPB), and the timed up-and-go test were performed to evaluate muscle strength, physical performance, and fall risk, respectively. The serum irisin was measured. High-resolution peripheral quantitative computed tomography (HR-pQCT) was performed to acquire volumetric BMD and bone microarchitecture. Bivariate analysis was used to explore relationships between serum irisin level and muscle strength and HR-pQCT parameters. Univariate and multivariate linear regression analyses were performed to determine associations between serum irisin level and vBMD and cortical porosity (Ct.Po). Results: All participants had a median serum irisin level of 3.91 µg/ml. Participants with high fall risk had significantly lower serum irisin levels than those with low fall risk (2.22 µg/ml vs. 4.16 µg/ml, p=0.024). Irisin level was positively related to handgrip strength (rs=0.185, p=0.030) and SPPB performance. In univariate linear regression, serum irisin level was positively associated with cortical volumetric BMD (Ct.vBMD, radius: standardized ß=0.184, p=0.031; tibia: standardized ß=0.242, p=0.004), but it had no significant associations with Ct.vBMD after multivariate adjustment. After adjusting by age, height, serum sclerostin level, and body fat ratio, only Ct.Po at the distal radius had a significantly negative association with serum irisin level (standardized ß=-0.276, p=0.003). Conclusion: Postmenopausal women with lower serum irisin levels have a higher fall risk, weaker muscle strength, and higher cortical porosity. Moreover, serum irisin level has a positive association with Ct.vBMD, but it is affected by factors such as age.

A Chinese case of CHST3-related skeletal dysplasia and a systematic review.

PURPOSE: We reported a case with carbohydrate sulfotransferase 3 (CHST3) spondyloepiphyseal dysplasia and made a systematic review of all previously reported cases. METHODS: A 14.8-year-old boy underwent clinical, radiological, and genetic evaluations. The patients and five age-matched healthy boys accepted high-resolution peripheral quantitative computed tomography evaluation. All CHST3-related skeletal dysplasia cases from PubMed and Embase were collected and summarized. The genotype-phenotype correlation was analyzed. RESULTS: The proband complained of aggravated joint pain and had a compression fracture of L2 during his second decade. Physical examination showed a height Z score of -4.94, short limbs, and restricted movement of the elbows and knees. X-rays showed carpal epiphyseal dysplasia, enlargement of elbow and knee joints, and subluxation of the left hip. Echocardiography showed abnormal cardiac valves. Compared with the norm, his total and trabecular volumetric bone mineral density (BMD), and the microarchitecture of the trabecular bone had trends to be worse at the distal radius and tibia. Two novel missense variants of c.1343T>G and c.761C>G in CHST3 were inherited from his father and mother, respectively. In the systematic review, short stature, limited joint extension, joint pain, and joint dislocation were the most common characteristics of this disorder. Height Z score and the proportion of hearing impairment had no significant differences between the missense and nonmissense mutations groups. CONCLUSION: Progressive joint pain and movement restriction are the main characteristics of CHST3-related skeletal dysplasia. BMD and bone microarchitecture of this disorder needs further exploration. There is no apparent genotype-phenotype correlation in this disorder.

Association of early-life famine exposure with low bone mass in adulthood.

Famine exposure in early life has been found to have a long-term effect on metabolic diseases, but its effect on bone health was not clear. In this study, we found women, who suffered from famine exposure during their childhood or adolescence period, had significantly decreased BMD at several skeletal sites compared to the age-matched non-exposed groups. The risk of clinical fracture was also elevated in adolescence-exposed women. PURPOSE: To investigate the correlation between famine exposure at certain stages and bone mass in adulthood. METHODS: We enrolled participants born in 1943-1962 from the China Osteoporosis Prevalence Study (COPS), which were classified into three famine exposure groups according to their birth year: fetal-famine exposure (1959-1962, n = 1693), childhood-famine exposure (1949-1958, n = 5557), and adolescence-famine exposure (1943-1948, n = 1530). We also selected age-balanced non-exposed participants as the control groups for men and women separately. Bone mineral density (BMD) and vertebral fractures (VFs) were measured by dual X-ray absorptiometry (DXA) and X-ray, respectively. The associations of famine exposure in early life with BMD were assessed via multiple linear regression. Logistic regression was performed to examine the association of famine exposure in early life with fracture risk with adjustments for covariates. RESULTS: In women, the childhood-exposed and adolescence-exposed groups had significantly decreased BMD at several skeletal sites compared to the age-matched non-exposed groups. No significant decreased BMD was found in the fetal-exposed groups compared to the non-exposed groups in both sexes. Multiple linear regression analysis showed that famine exposure during childhood and adolescence was negatively associated with BMD at the femoral neck after adjusting for covariates in women. The risk of clinical fracture was also elevated in adolescence-exposed women. CONCLUSION: Famine exposure during early life especially childhood and adolescence is associated with decreased bone mass in adulthood in women but did not affect bone mass in men.

Evaluation of Volumetric Bone Mineral Density, Bone Microarchitecture, and Bone Strength in Patients with Achondroplasia Caused by FGFR3 c.1138G > A Mutation.

Achondroplasia (ACH) is a skeletal disorder caused by fibroblast growth factor receptor 3 (FGFR3) variants. Volumetric bone mineral density (vBMD), bone microarchitecture, and strength have not been evaluated in these patients previously. This study aims to evaluate vBMD, bone microarchitecture, and strength in ACH patients. Seventeen patients underwent clinical and biochemical evaluations, and genetic testing. High-resolution peripheral quantitative computed tomography was performed in 10 ACH patients and 21 age- and sex-matched healthy subjects. All individuals had the hotspot mutation of c.1138G > A in FGFR3. Linear growth retardation, disproportionate short stature, and genu varum are the most common manifestations. The mean height was 108.82 ± 24.08 cm (Z score: - 5.72 ± 0.96). Total vBMD in the ACH and the control groups was 427.08 ± 49.29 mg HA/cm3 versus 300.35 ± 69.92 mg HA/cm3 (p < 0.001) at the radius and 336.90 ± 79.33 mg HA/cm3 versus 292.20 ± 62.35 mg HA/cm3 (p = 0.098) at the tibia; both at the radius and tibia, vBMD of trabecular bones was significantly lower in the ACH group than in the control group, but vBMD of cortical bones was slightly higher in the ACH group. Trabecular separation and cortical thickness in the ACH group were significantly higher than those in the control group, but trabecular number was significantly decreased in the ACH group. Stiffness and failure load were only better at the radius in the ACH group. ACH patients have higher total and cortical vBMD, lower trabecular vBMD, worse trabecular bone microarchitecture, thicker cortical bone thickness, and better estimated bone strength.

Marginal bone loss of tissue- or bone-level implants after simultaneous guided bone regeneration in the posterior mandibular region: A retrospective cohort study.

PURPOSE: To analyze the marginal bone loss (ΔMBL) of tissue- or bone-level implants after placed with simultaneous guided bone regeneration (GBR). MATERIALS AND METHODS: A total of 151 patients who received 104 tissue-level or 128 bone-level implants placement with simultaneous GBR in the mandibular posterior region between January 2011 and December 2016 were included in this study. The marginal bone level (MBL) was recorded using the radiographic data obtained at implant placement, second-stage surgery, and the follow-up visit. Generalized estimating equation (GEE) was used to compare the ΔMBL of tissue- and bone-level implants, and the influencing factors of ΔMBL were further analyzed. RESULTS: At the last follow-up visit, the MBL of tissue-level implants was 0.73 ± 0.86 mm, above the rough-smooth interface, while that of bone-level implants was 0.82 ± 1.05 mm, above the implant platform. The ΔMBL of tissue-level implants was 1.03 mm, which was slightly higher than 0.81 mm of bone-level implants, but there was no significant difference (p > 0.05). No contributing factor associated with ΔMBL was identified by multivariate regression analysis in this study. CONCLUSION: Within the limits of this retrospective analysis, the ΔMBL of tissue-level implants is similar to that of bone-level implants after placed with simultaneous GBR, and both types of implants can achieve desirable marginal bone stability.

Bone characteristics of autosomal dominant hypophosphatemic rickets patients.

OBJECTIVE: Autosomal dominant hypophosphatemic rickets (ADHR) is a rare disease caused by activating mutations in fibroblast growth factor 23 (FGF23) gene. With FGF23 activation, ADHR is a good model to explore the effects of FGF23 on skeletal development and mineralization. However, the bone microarchitecture of ADHR patients is poorly investigated. This study aims to illustrate the bone properties of ADHR patients and clarify the effect of FGF23 on load bearing and non-load bearing bone. METHODS: Bone microarchitectures of 11 ADHR subjects and sex- and age-matched healthy controls were analyzed by HR-pQCT. The effect of FGF23 mutations on load bearing and non-load bearing bone was explored by comparison of bone microarchitecture in distal radius and distal tibia. The BMD, bone microarchitecture and bone strength were compared between 7 ADHR patients and 7 age- and sex-matched XLH patients. RESULTS: Among 11 subjects with FGF23 mutations, 10 patients presented with obvious symptoms, five of which had received 1-3 years of iron supplement, neutral phosphate, and calcitriol treatments. The symptomatic patients presented with low bone density and fractures in X rays, with decreased Z score of aBMD (L1-L4: -1.3 ± 1.4, femoral neck: -2.1 ± 1.8, total hip: -1.85 ± 1.6). Compared with controls, HR-pQCT analysis of 5 untreated ADHR patients showed increased total area (+61.6 %, p = 0.03) and cortical perimeter (+17.2 %, p = 0.03) in distal radius. No significant differences were found in other parameters in distal radius. In distal tibia, the patients presented obvious defects in cancellous bone, with decreased trabecular vBMD (-62.9 %, p = 0.003), trabecular BV/TV (-48.7 %, p = 0.003) and trabecular number (-42.2 %, p = 0.001). The trabecular separation (+113.3 %, p = 0.007) and trabecular network inhomogeneity (+226.7 %, p = 0.001) were accordingly increased. In addition to another 5 treated patients, the bone microarchitecture changes revealed similar pattern, but the increase of total area and cortical perimeter in distal radius was no longer statistically significant. The non-symptomatic ADHR patient demonstrated slightly decreased total vBMD, trabecular vBMD and trabecular BV/TV in distal tibia. The changing pattern of bone geometry and microarchitecture of ADHR patients were similar to XLH patients but showed less deficit and stronger bone strength. CONCLUSION: ADHR patients presented increased total area and cortical perimeter in distal radius, and obvious defect in cancellous bone in distal tibia. FGF23 have impairment effect on trabecular bone especially in weight bearing site.

Clinical characteristics and the influence of rs1800470 in patients with Camurati-Engelmann disease.

Background: Camurati-Engelmann disease (CED) is a sclerosing bone dysplasia caused by transforming growth factor ß1 (TGFB1) gene variants. Objective: We aim to summarize the clinical characteristics and the efficacy of glucocorticoids in 14 individuals with CED, and explore the correlation between the phenotype and the SNP of rs1800470 (c.29C>T). Methods: Clinical, biochemical, radiological, and therapeutic data were collected from 14 patients. DNA was extracted for TGFB1 variants detection by Sanger sequencing. Results: The median onset and record age were 3.0 and 16.1 years, respectively. All patients manifested bone pain and decreased subcutaneous fat tissue. Inflammatory markers increased in over 60% of patients, and the median erythrocyte sedimentation rate (ESR) was 1.40 (0.50~3.67) of the upper limit of normal (ULN), and the median high sensitivity C reactive protein (hsCRP) was 1.71 (0.48~12.56) of ULN. There was a positive correlation between ESR and hsCRP (rs=0.806, p=0.003). Both ESR and hsCRP were negatively correlated with the levels of hemoglobin (HGB), calcium, and creatinine, but positively correlated with the level of alkaline phosphatase. Four known variants of TGFB1 were identified, including p.Tyr171Cys, p.Arg218Cys, p.Arg218His, and p.Cys225Arg. Moreover, 35.7% and 28.6% of them carried the heterozygous and homozygous SNP of c.29C>T, called C/T and T/T groups, respectively, but 35.7% of them were without c.29C>T (C/C group). The onset age, anthropometric data, percentages of different clinical manifestations, and biochemical parameters were comparable among the three groups. But there were increasing trends in levels of HGB and calcium and decreasing trends in ESR and hsCRP among C/C, C/T, and T/T groups in turn. Glucocorticoid improves the two inflammatory markers among CED patients. Conclusion: The phenotype of CED is highly heterogeneous. There is no clear genotype-phenotype correlation, but it seems to have better trends of biochemical parameters in patients with CED carrying the T allele of rs1800470.

Bone Microarchitecture in Obese Postmenopausal Chinese Women: The Chinese Vertebral Osteoporosis Study (ChiVOS).

Background: Obesity is associated with improved bone mass and microarchitecture in Caucasian individuals, but evidence in obese Asian individuals is lacking. Objective: To analyze the areal bone mineral density (aBMD) and bone microarchitecture in normal-weight, overweight, and obese postmenopausal Chinese women. Methods: A total of 243 postmenopausal women from the Chinese Vertebral Osteoporosis Study (ChiVOS) were included and were divided into three groups (OB, obese group; OW, overweight group; NW, normal weight group) by BMI level. aBMD, trabecular bone score (TBS), and appendicular lean mass (ALM) were measured by dual-energy X-ray absorptiometry (DXA). Bone microarchitecture was measured by HR-pQCT at the distal radius and tibia. X-ray was performed to confirm vertebral fractures (VFs). Multiple linear regression was used to evaluate the correlations between bone parameters and ALM after adjusting for confounding variables. Results: The prevalence of VFs and clinical fractures were similar among the groups. Participants in the OB group showed a lower level of osteocalcin with comparable levels of other bone turnover markers (BTMs). The aBMD at several skeletal sites was higher in the OB group than in the NW group after adjusting for age (p<0.01 for all comparisons). At the radius, the OB group had a higher Ct.Ar, Tb.vBMD, Tb.BV/TV, Tb.N, Tb.Th, and Ct.Th than the NW group after adjusting for covariates (p<0.05 for all). Differences of a similar magnitude were found at the distal tibia. There was a trend of decreasing trend in Tb.Sp, Tb.1/N/SD, and Ct.Po among groups at both sites. However, the bone microarchitecture did not differ between participants with severe obesity (BMI≥35.0kg/m2) and those with 30.0≤BMI<35 kg/m2. Multiple linear regression revealed that the associations between ALM and most of the bone microarchitecture parameters at both sites were much stronger than the association between body weight and bone parameters. Conclusion: We have observed significant improvements in aBMD, bone geometry, and bone microarchitecture in obese postmenopausal Chinese women. Except for a lower level of osteocalcin in the OB group, no significant differences in BTMs were found among the groups. Compared with body weight, ALM may explain greater variance in the improvement of bone microarchitecture parameters.

Na-Cl Co-transporter (NCC) gene inactivation is associated with improved bone microstructure.

Gitelman syndrome (GS) is the disease model of the inactivation of thiazide-sensitive sodium chloride cotransporter (NCC), which is believed to benefit bone mass and reduce fracture risk. In this study, we found that GS patients have superior bone microarchitecture, which is associated with the disease status. Several decreased bone parameters with aging in healthy controls were reversed in GS patients to a certain extent. PURPOSE: To evaluate the impact of the inactivation of NCC on bone turnover and microarchitecture in Gitelman syndrome patients. METHODS: A cross-sectional study was conducted in 45 GS patients (25 males and 20 females). Serum procollagen type 1 N-terminal propeptide (P1NP), ß-carboxy-terminal crosslinked telopeptide of type 1 collagen (ß-CTX), and osteocalcin were measured. High-resolution peripheral quantitative computed tomography (HR-pQCT) was conducted to evaluate bone microarchitecture in GS patients and age- and sex-matched healthy controls. Areal bone mineral density (aBMD) was measured by dual-energy X-ray absorptiometry (DXA) simultaneously. RESULTS: GS patients had a relatively lower level of ß-CTX. aBMD at several skeletal sites was improved in GS patients. HR-pQCT assessment revealed that GS patients had slightly thinner but significantly more compact trabecular bone (increased trabecular number and decreased thickness), notably decreased cortical porosity, and increased volume BMD (vBMD) at both the radius and tibia compared with controls. The disease severity, represented as the relationship with the minimum level of magnesium during the course and standard base excess, was associated with bone microarchitecture parameters after adjusting for age, sex, and BMI. The decreased vBMD and Tb.BV/TV, and increased Tb.Sp and Ct.Po with aging, were reversed in GS patients to a certain extent. CONCLUSION: GS patients have superior bone microarchitecture, which suggests that the inactivation of NCC might be beneficial for avoiding osteoporosis.

LRP5 promotes cancer stem cell traits and chemoresistance in colorectal cancer.

The overactivation of canonical Wnt/ß-catenin pathway and the maintenance of cancer stem cells (CSCs) are essential for the onset and malignant progression of most human cancers. However, their regulatory mechanism in colorectal cancer (CRC) has not yet been well demonstrated. Low-density lipoprotein receptor-related protein 5 (LRP5) has been identified as an indispensable co-receptor with frizzled family members for the canonical Wnt/ß-catenin signal transduction. Herein, we show that activation of LRP5 gene promotes CSCs-like phenotypes, including tumorigenicity and drug resistance in CRC cells, through activating the canonical Wnt/ß-catenin and IL-6/STAT3 signalling pathways. Clinically, the expression of LRP5 is upregulated in human CRC tissues and closely associated with clinical stages of patients with CRC. Further analysis showed silencing of endogenous LRP5 gene is sufficient to suppress the CSCs-like phenotypes of CRC through inhibiting these two pathways. In conclusion, our findings not only reveal a regulatory cross-talk between canonical Wnt/ß-catenin signalling pathway, IL-6/STAT3 signalling pathway and CD133-related stemness that promote the malignant behaviour of CRC, but also provide a valuable target for the diagnosis and treatment of CRC.

Dental follicles promote soft tissue management in surgical exposure of labially impacted maxillary canine.

BACKGROUND: The present study aimed to report a technically improved operation on the surgical exposure of labially impacted maxillary canine, elaborating the management of soft tissue to achieve better aesthetic results, and post-treatment periodontal health. METHODS: Patients sought orthodontic treatment with unilateral labially impacted maxillary canines were selected in this study. The impacted teeth were assigned to the experimental group and contralateral unimpacted canines were assigned to the control group. The impacted canines were surgically exposed with dissected dental follicle (DF) stitching to muscle and mucosa surrounding the crowns. The gingival index (GI), probing depth (PD), the width of the keratinized gingiva (WKG), gingival scars (GS), bone loss (BL), and apical root resorption (ARR) were recorded after the removal of the fixed appliance. A two-sample t-test was used for independent samples for parametric variables. RESULTS: A total of 24 patients with unilateral maxillary canine impaction were successfully treated. The outcomes of GI, WKG, GS, BL, and ARR did not indicate statistical significance between the experimental group and the control group. CONCLUSIONS: The preservation of DF promotes soft tissue management in combined surgical and orthodontic treatment of labially impacted maxillary canine to achieve better periodontal status. Trial Registration Chinese Clinical Trial Registry ChiCTR2000029091, 2020-01-12.

A Nighttime Vehicle Detection Method with Attentive GAN for Accurate Classification and Regression.

Vehicle detection plays a vital role in the design of Automatic Driving System (ADS), which has achieved remarkable improvements in recent years. However, vehicle detection in night scenes still has considerable challenges for the reason that the vehicle features are not obvious and are easily affected by complex road lighting or lights from vehicles. In this paper, a high-accuracy vehicle detection algorithm is proposed to detect vehicles in night scenes. Firstly, an improved Generative Adversarial Network (GAN), named Attentive GAN, is used to enhance the vehicle features of nighttime images. Then, with the purpose of achieving a higher detection accuracy, a multiple local regression is employed in the regression branch, which predicts multiple bounding box offsets. An improved Region of Interest (RoI) pooling method is used to get distinguishing features in a classification branch based on Faster Region-based Convolutional Neural Network (R-CNN). Cross entropy loss is introduced to improve the accuracy of classification branch. The proposed method is examined with the proposed dataset, which is composed of the selected nighttime images from BDD-100k dataset (Berkeley Diverse Driving Database, including 100,000 images). Compared with a series of state-of-the-art detectors, the experiments demonstrate that the proposed algorithm can effectively contribute to vehicle detection accuracy in nighttime.

An Adaptive Deblurring Vehicle Detection Method for High-Speed Moving Drones: Resistance to Shake.

Vehicle detection is an essential part of an intelligent traffic system, which is an important research field in drone application. Because unmanned aerial vehicles (UAVs) are rarely configured with stable camera platforms, aerial images are easily blurred. There is a challenge for detectors to accurately locate vehicles in blurred images in the target detection process. To improve the detection performance of blurred images, an end-to-end adaptive vehicle detection algorithm (DCNet) for drones is proposed in this article. First, the clarity evaluation module is used to determine adaptively whether the input image is a blurred image using improved information entropy. An improved GAN called Drone-GAN is proposed to enhance the vehicle features of blurred images. Extensive experiments were performed, the results of which show that the proposed method can detect both blurred and clear images well in poor environments (complex illumination and occlusion). The detector proposed achieves larger gains compared with SOTA detectors. The proposed method can enhance the vehicle feature details in blurred images effectively and improve the detection accuracy of blurred aerial images, which shows good performance with regard to resistance to shake.

Three-dimensional printed model of impacted third molar for surgical extraction training.

OBJECTIVES: Extraction of impacted mandibular third molars is one of the most common surgical procedures performed at dental clinics; however effective training models for teaching oral surgery to dental students are limited. This study aimed to use three-dimension (3D) printing technology to develop an effective training model for impacted third molar extraction. METHODS: The data for the 3D model were digitally processed using high-resolution computed tomography, and two common, but different patterns of impacted third molars were simulated using computer-aided design. Thereafter, the model was printed using the 3D-printing technology, and the efficiency of the 3D-printed model and an animal model (pig mandible) were compared using a five-point Likert scale by 35 oral surgeons in the oral surgery department and 208 students of stomatology in the internship stage. RESULTS: The 3D-printed model consisted of three parts: a non-replaceable part (i.e., the body of the mandible and the teeth from the left first molar to the right first molar) and two replaceable parts (i.e., the part of the ascending ramus of the mandible, as well as the second and third molars). It was covered with a layer of rubber-like material to simulate the gingiva. For the comparison between the 3D-printed and animal models, a total of 205 questionnaires were collected. Both oral surgeons and students agreed that the 3D-printed model was better than the animal model in terms of total value and the anatomy of the bone and teeth, simulating the surgical procedure (p < 0.05), while the two models achieved similar results for haptic feedback of the soft tissue (p > 0.05). CONCLUSIONS: The 3D-printed model is realistic and effective for learning impacted third molar extraction and received positive feedback from students and oral surgeons. This model can significantly improve the pre-clinical skill training of dental students.

Serial cellular events in bone formation initiated by calcium phosphate ceramics.

To better understand the biological mechanisms triggered by osteoinductive materials in vivo, we evaluated the timeline of cellular responses to osteoinductive materials subcutaneously implanted in FVB mice. More F4/80-positive macrophages were present in osteoinductive tri-CaP ceramic (TCP) with submicron surface topography (TCPs) than non-osteoinductive TCP with micron surface topography (TCPb) at week 1. Moreover, TCPs (but not TCPb) significantly enhanced osteoclastogenesis, and induced macrophages to polarize from M1 to M2 in the first week. The time sequence and relevance of macrophages and osteoclasts responses involved in bone formation was then evaluated through peri-implant injection of specific chemicals in mice implanted with osteoinductive TCPs. Day-1 injection of clodronate liposomes (LipClod) depleted macrophages, inhibited macrophage polarization to M2, blocked osteoclastogenesis and bone formation, while the day-6 injection was less effective. Anti-RANKL antibody (aRANKL) did not affect macrophage colonization but inhibited osteoclastogenesis. Injection of aRANKL before week 2 aborted bone formation in TCPs, while injection at week 4 partially inhibited bone formation. The overall data show that following ectopic implantation, osteoinductive materials allow macrophage colonization in hours to days, macrophage polarization to M2 in days (within 7 days), osteoclastogenesis in weeks (e.g. in 2 weeks) and bone formation thereafter (after 4 weeks). The serial cellular events verified herein bring a new insight on material-induced bone formation and pave the way to further explore the mechanisms triggered by osteoinductive materials. STATEMENT OF SIGNIFICANCE: A series of key cellular events triggered by osteoinductive calcium phosphate ceramic was revealed: macrophages colonized within hours to days, polarization of M2 macrophages occurred within 7 days, osteoclastogenesis mainly occurred in weeks (e.g. in 2 weeks) and bone formation finally arose thereafter (after 4 weeks). Moreover, such time sequence of cellular events was confirmed with specific chemicals (clodronate liposomes and anti-RANKL antibody). The findings verified herein bring a new insight on material-induced bone formation and pave the way to further explore the mechanisms triggered by osteoinductive materials.

Macrophage polarization plays roles in bone formation instructed by calcium phosphate ceramics.

To investigate the roles of macrophages in material-instructed bone formation, two calcium phosphate (TCP) ceramics with the same chemistry but various scales of surface topography were employed in this study. After being implanted subcutaneously in FVB mice for 8 weeks, TCPs (TCP ceramics with submicron surface topography) gave rise to bone formation, while TCPb (TCP ceramics with micron surface topography) did not, showing the crucial role of surface topography scale in material-instructed bone formation. Depletion of macrophages with liposomal clodronate (LipClod) blocked such bone formation instructed by TCPs, confirming the role of macrophages in material-instructed bone formation. Macrophage cells (i.e. RAW 264.7 cells) cultured on TCPs in vitro polarized to tissue repair macrophages as evidenced by gene expression and cytokine production, while polarizing to pro-inflammatory macrophages on TCPb. Submicron surface topography of TCP ceramics directed macrophage polarization via PI3K/AKT pathways with the synergistic regulation of integrin ß1. Finally, the tissue repair macrophage polarization on TCPs resulted in osteogenic differentiation of mesenchymal stem cells in vitro. At early implantation in FVB mice, TCPs recruited more macrophages which polarized towards tissue repair macrophages with time. The present data demonstrate the important roles of macrophage polarization in bone formation instructed by calcium phosphate ceramics.

Facial alveolar bone alterations and gray value changes based on cone beam computed tomography around maxillary anterior implants: A clinical retrospective study of 1-3 years.

OBJECTIVES: The purpose of this cone beam computed tomography (CBCT) study was to describe facial alveolar bone alterations and gray value (GV) changes around implants in aesthetic anterior maxilla with simultaneous guided bone regeneration (GBR) and to investigate potential influence of factors related to vertical alveolar bone stability, such as particle sizes of the deproteinized bovine bone mineral (DBBM) used. MATERIALS AND METHODS: A retrospective study design was adopted. Four facio-palatal cross-sectional CBCT images of 166 implants from 124 patients who had maxillary anterior implants were obtained. Measurements of the vertical facial alveolar bone level (VFBL), horizontal facial alveolar bone thickness (HFBT), and GV were identified of 1-3 years. Then, correlation coefficients for those parameters were calculated. Finally, linear mixed models were established to investigate potential factors influencing vertical alveolar bone resorption. RESULTS: Facial alveolar bone underwent fast bone modeling and remodeling during the first 6 months, with decreases of 1.00 ± 1.19 and 0.74 ± 0.86 mm in VFBL and HFBT in implant shoulder, respectively, and there was positive and significant correlation between the alterations in VFBL and HFBT1 (rs  = .516, p = .000). Linear mixed models identified particle size of DBBM as a critical factor associated with vertical bone resorption (p = .000). The GV gradually increased during the follow-up period. CONCLUSIONS: Rapid and unavoidable peri-implant bone resorption usually happened during the first 6 months after implant placement. GBR is a predictable treatment for maxillary anterior implants, since GV has an increasing trend. Large bone particles of DBBM help maintain vertical alveolar bone stability.