Camera calibration optimization algorithm that uses a step function.

Camera calibration is very important when planning machine vision tasks. Calibration may involve 3D reconstruction, size measurement, or careful target positioning. Calibration accuracy directly affects the accuracy of machine vision. The parameters in many image distortion models are usually applied to all image pixels. However, this may be associated with rather high pixel reprojection errors at image edges, compromising camera calibration accuracy. In this paper, we present a new camera calibration optimization algorithm that features a step function that splits images into center and edge regions. First, based on the increasing pixel reprojection errors according to the pixel distance away from the image center, we gave a flexible method to divide an image into two regions, center and boundary. Then, the algorithm automatically determines the step position, and the calibration model is rebuilt. The new model can calibrate the distortions at the center and boundary regions separately. Optimized by the method, the number of distortion parameters in the old model is doubled, and different parameters represent different distortions within two regions. In this way, our method can optimize traditional calibration models, which define a global model to describe the distortion of the whole image and get a higher calibration accuracy. Experimentally, the method significantly improved pixel reprojection accuracy, particularly at image edges. Simulations revealed that our method was more flexible than traditional methods.

Identification and immunological role of cuproptosis in osteoporosis.

Background: osteoporosis is a skeletal disorder disease features low bone mass and poor bone architecture, which predisposes to increased risk of fracture. Copper death is a newly recognized form of cell death caused by excess copper ions, which presumably involve in various disease. Accordingly, we intended to investigate the molecular clusters related to the cuproptosis in osteoporosis and to construct a predictive model. Methods: we investigated the expression patterns of cuproptosis regulators and immune signatures in osteoporosis based on the GSE56815 dataset. Through analysis of 40 osteoporosis samples, we investigated molecular clustering on the basis of cuproptosis--related genes, together with the associated immune cell infiltration. The WGCNA algorithm was applied to detect cluster-specific differentially expressed genes. Afterwards, the optimum machine model was selected by calculating the performance of the support vector machine model, random forest model, eXtreme Gradient Boosting and generalized linear model. Nomogram, decision curve analysis, calibration curves, and the GSE7158 dataset was utilizing to confirm the prediction efficiency. Results: Differences between osteoporotic and non-osteoporotic controls confirm poorly adjusted copper death-related genes and triggered immune responses. In osteoporosis, two clusters of molecules in connection with copper death proliferation were outlined. The assessed levels of immune infiltration showed prominent heterogeneity between the different clusters. Cluster 2 was characterized by a raised immune score accompanied with relatively high levels of immune infiltration. The functional analysis we performed showed a close relationship between the different immune responses and specific differentially expressed genes in cluster 2. The random forest machine model showed the optimum discriminatory performance due to relatively low residuals and root mean square errors. Finally, a random forest model based on 5 genes was built, showing acceptable performance in an external validation dataset (AUC = 0.750). Calibration curve, Nomogram, and decision curve analyses also evinced fidelity in predicting subtypes of osteoporosis. Conclusion: Our study identifies the role of cuproptosis in OP and essentially illustrates the underlying molecular mechanisms that lead to OP heterogeneity.

Zhuanggu Zhitong Capsule alleviates postmenopausal osteoporosis in ovariectomized rats by regulating autophagy through AMPK/mTOR signaling pathway.

Background: Postmenopausal osteoporosis (PMOP) is the most common primary osteoporosis, which is prone to fractures and affect the health and quality of life of the elderly and even shorten their lifetime. Traditional Chinese medicine can not only effectively improve osteoporosis and reduce fracture rate, but also have tonifying and analgesic effects. The purpose of this study was to investigate the effects of Zhuanggu Zhitong (ZGZT) Capsule on autophagy related genes and proteins in PMOP rats, so as to elucidate the molecular mechanism of tonifying deficiency and regulating stasis in the treatment of osteoporosis and analgesia. Methods: The PMOP rat model was established by bilateral oophorectomy, and then the rats were randomly divided into control group, PMOP group, PMOP + ZGZT group and PMOP + E2 group. The changes of mechanical pain threshold of rats were detected by von Frey filaments, and the changes of mechanical pain threshold of rats in each group were compared. Computed tomography (CT) and dual-energy X-ray were used to measure the bone mineral density of lumbar bone tissue. Enzyme-linked immunosorbent assay (ELISA) and tartrate-resistant acid phosphatase (TRAP) staining were used to detect inflammatory factors and bone metabolism related indicators. Hematoxylin-eosin (HE) staining was used to observe the tissue morphology of lumbar vertebra tissue. Western blot (WB) and quantitative polymerase chain reaction (qPCR) were used to detect AMPK/mTOR pathway- and autophagy-related factor expression. Results: ZGZT can effectively restore the bone mineral density (BMD) of PMOP rats, improve the microstructure of lumbar vertebra of PMOP rats, restore the balance of bone metabolism, promote the expression of AMPK and autophagy related factors, inhibit the expression of mTOR and the release of inflammatory factors, and increase the mechanical pain threshold of PMOP rats, so as to effectively improve osteoporosis and relieving osteoporosis pain in PMOP rats. Conclusions: ZGZT affects autophagy by regulating AMPK/mTOR pathway, restores the homeostasis of bone metabolism and inhibits the release of inflammatory factors. Moreover, the regulation of feedback pathways between bone metabolism and inflammatory factors finally plays the role of "bone strengthening" and "pain relieving". ZGZT may be a new treatment for PMOP and relieving osteoporotic pain.

Cistanoside A promotes osteogenesis of primary osteoblasts by alleviating apoptosis and activating autophagy through involvement of the Wnt/ß-catenin signal pathway.

Background: As a phenylethanoid glycoside extracted from Cistanche deserticola, cistanoside A has been shown to have antioxidative effects. In recent years, it has been found to play an important role in osteoporosis. Methods: Primary osteoblasts were randomly divided into a cistanoside A (Cis A)-1 group (5 µM), a Cis A-2 group (10 µM), and a Cis A-3 group (20 µM) to screen the optimal dose. Then, cells were treated with Rapamycin (Rapa), 3-MA, Dickkopf-1 (DKK-1), 3MA + Cis A (10 µM), and DKK-1 + Cis A (10 µM). After a certain period of routine culture, Alkaline Phosphatase (ALP) and Alizarin Red S Staining were performed again and the cells were collected for subsequent experiments including immunofluorescence staining, western blotting, transmission electron microscopy, mitochondrial membrane measurement, and Annexin-V-Fluorescein isothiocyanate (Annexin-V-FITC). Results: The optimal Cis A dose that preserved osteoblast viability and activated osteogenesis was 10 µM. It appeared that Cis A (10 µM) decreased apoptosis and augmented autophagy via increasing microtubule-associated protein light chain 3 (LC3)-I/II expressions as well as raising Wnt/ß-catenin signal pathway activity. The addition of 3-MA further inhibited osteogenic differentiation and suppressed Wnt/ß-catenin signal pathway activity to increase apoptosis while reducing autophagy levels. A combination of Cis A and DKK-1 resulted in higher levels of apoptosis but lower levels of autophagy. Conclusions: Cis A appears to be a potent inducer of autophagy and inhibitor of apoptosis in primary osteoblasts by working through the Wnt/ß-catenin signal pathway, thereby resulting in enhanced osteogenic differentiation.

Systematic analysis of long non-coding RNA and mRNA profiling using RNA sequencing in the femur and muscle of ovariectomized rats.

OBJECTIVE: To investigate the expression profile of lncRNAs in bone and skeletal muscle of ovariectomized (OVX) rats. METHODS: Six-month-old female Sprague-Dawley (SD) rats were divided into OVX group (ovariectomized, n=12) and sham group (sham-operated, n=12). After 12 weeks, RNA-seq was used to analyze the differential expression of lncRNAs and mRNAs in femur and quadriceps between two groups. Dys-regulated expression of lncRNAs was confirmed by qRT-PCR. The cis and trans-regulatory functions were analyzed to determine their function and biological processes. Lastly, GO and KEGG analyses were performed to assess the biological relevance of genes in each profile. RESULTS: A total of 17 lncRNAs and 440 mRNAs were differentially expressed in the femur. Thirteen lncRNAs and 292 mRNAs were differentially expressed in the quadriceps. qRT-PCR results were in consistent with the RNA-seq data. Among them, ENSRNOT00000090777 was found in both femur and quadriceps samples. Bioinformatics analysis found that LNC_004549 participated in the differentiation of skeletal and skeletal muscle. CONCLUSIONS: The expression profile of lncRNAs was significantly altered in femur and quadriceps of OVX rat models, which may offer new insights into pathogenesis of osteoporosis and sarcopenia and potentially provide novel therapeutic targets.

Gushukang inhibits osteocyte apoptosis and enhances BMP-2/Smads signaling pathway in ovariectomized rats.

BACKGROUND: Traditional herbal formula Gushukang (GSK) has been clinically applied to treat primary osteoporosis, which can stimulate osteoblastogenesis and improve calcium homeostasis. However, it remains unknown the mechanism that GSK against ovariectomized (OVX) induced damage. PURPOSE: The aim of this study was to investigate the effect of GSK on BMP-2/Smsds signaling pathway and osteocyte apoptosis which has been reported to play a central role in bone remodeling. STUDY DESIGN: OVX in rat was established and GSK was administered. RESULTS: BMP-2/Smsds signaling pathway was inhibited and the number of apoptotic osteocytes was increased in OVX rats. Treatment with GSK significantly enhanced BMP-2/Smsds signaling pathway by up-regulating the expression of BMP-2, p-Smad1 and p-Smad5, Osterix and Runx2, and inhibited osteocyte apoptosis by up-regulating Bcl-xl and down-regulating Bak, which were consistent with histological changes revealed by ALP, Trap and TUNEL staining. GSK treatment improved bone mass and micro-structure of trabecular bone at distal femur in OVX rats shown by BMD, micro-CT measurement and HE staining. CONCLUSION: These data suggest that GSK exhibited protective effects on promoting bone formation and precluding osteocyte apoptosis. The underlying mechanism may be attributed to its regulation on BMP-2/Smads signaling pathway and Bcl2 family.

Expression profile analysis of long non-coding RNA in skeletal muscle of osteoporosis by microarray and bioinformatics.

BACKGROUND: Osteoporosis (OP) is a condition featured by bone mass loss and bone tissue microarchitectural alterations due to impaired tissue homeostasis favoring excessive bone resorption versus deposition. The trigger of such an impairment and the downstream molecular pathways involved are yet to be clarified. Long non-coding RNA (lncRNA) plays a role in gene transcription, protein expression and epigenetic regulation; and altered expression results in immune or metabolism related desease development. To determine whether lncRNAs are involved in osteoporosis, we analyzed the expression profile of lncRNAs and mRNAs in osteoporosis. METHOD: Three pairs of osteoporosis patients (OP group) and healthy people controls (NC group) were screened by microarray. Quantitative polymerase chain reaction (qRT-PCR) was performed to confirm dysregulated lncRNA expressions in 5 pairs of OP and NC group tissues samples. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to construct the lncRNA-mRNA co-expression network. RESULT: Through co-expression analysis, differently expressed transcripts were divided into modules, and lncRNAs were functionally annotated. We further analyzed the clinical significance of crucial lncRNAs from modules in public data. Finally, the expression of five lncRNAs, CUST_44695_PI430048170-GeneSymbol:CTA-384D8.35;CUST_39447_PI430048170,CUST_73298_PI430048170,CUST_108340_PI430048170,CUST_118927_PI430048170,this four lncRNAs have not been annotation genes and have not found GeneSymbols, and by quantitative RT-PCR, which may be associated with osteoporosis patients' overall survival. CONCLUSION: Analysis of this study revealed that dysregulated lncRNAs and mRNAs in osteoporosis patients and health people controls could affect the immune or metabolism system and musculoskeletal cell differentiation. The biological functions of those lncRNAs need to be further validated.

A novel parainfluenza virus type 3 (PIV3) identified from goat herds with respiratory diseases in eastern China.

Parainfluenza virus type 3 (PIV3) is one of the most important viral respiratory pathogens for humans and for many animals, but goat infection has been rarely reported. Starting in Aug 2013, goats in the Jiangsu and Anhui provinces of eastern China suffered severe respiratory diseases. In order to identify the causative agent, numerous related pathogens were tested with RT-PCR or PCR. A unique PIV3 strain was detected in most of the clinical nasal swabs or serum samples. The virus was isolated on MDBK cells and characterized by RT-PCR, nucleotide sequence analysis and hemagglutination test. The entire M and F gene coding regions, HN, 5'-UTR-N and L gene fragments were amplified using pairs of degenerate primers. Nucleotide, amino acid sequence alignments and phylogenetic analyses based on these genes indicated that the goat-derived PIV3 strain was distinct from previously reported BPIV3 genotypes and HPIV3 strains. The novel isolate, named JS2013, might be a potentially new member of the respirovirus genus. Goats were experimentally infected with JS2013 culture. The virus-inoculated goats displayed coughing and nasal discharges that were related to respiratory diseases. Viremia and virus shedding were detected during 4-10 days post-inoculation (dpi). Virus-specific HI antibodies became positive from 14 dpi. This is the first report of the detection of PIV3 from Chinese goat herds and genetic and pathogenetic characterization of the novel goat-derived PIV3.