A Study on Dimensionality Reduction and Parameters for Hyperspectral Imagery Based on Manifold Learning.

With the rapid advancement of remote-sensing technology, the spectral information obtained from hyperspectral remote-sensing imagery has become increasingly rich, facilitating detailed spectral analysis of Earth's surface objects. However, the abundance of spectral information presents certain challenges for data processing, such as the "curse of dimensionality" leading to the "Hughes phenomenon", "strong correlation" due to high resolution, and "nonlinear characteristics" caused by varying surface reflectances. Consequently, dimensionality reduction of hyperspectral data emerges as a critical task. This paper begins by elucidating the principles and processes of hyperspectral image dimensionality reduction based on manifold theory and learning methods, in light of the nonlinear structures and features present in hyperspectral remote-sensing data, and formulates a dimensionality reduction process based on manifold learning. Subsequently, this study explores the capabilities of feature extraction and low-dimensional embedding for hyperspectral imagery using manifold learning approaches, including principal components analysis (PCA), multidimensional scaling (MDS), and linear discriminant analysis (LDA) for linear methods; and isometric mapping (Isomap), locally linear embedding (LLE), Laplacian eigenmaps (LE), Hessian locally linear embedding (HLLE), local tangent space alignment (LTSA), and maximum variance unfolding (MVU) for nonlinear methods, based on the Indian Pines hyperspectral dataset and Pavia University dataset. Furthermore, the paper investigates the optimal neighborhood computation time and overall algorithm runtime for feature extraction in hyperspectral imagery, varying by the choice of neighborhood k and intrinsic dimensionality d values across different manifold learning methods. Based on the outcomes of feature extraction, the study examines the classification experiments of various manifold learning methods, comparing and analyzing the variations in classification accuracy and Kappa coefficient with different selections of neighborhood k and intrinsic dimensionality d values. Building on this, the impact of selecting different bandwidths t for the Gaussian kernel in the LE method and different Lagrange multipliers λ for the MVU method on classification accuracy, given varying choices of neighborhood k and intrinsic dimensionality d, is explored. Through these experiments, the paper investigates the capability and effectiveness of different manifold learning methods in feature extraction and dimensionality reduction within hyperspectral imagery, as influenced by the selection of neighborhood k and intrinsic dimensionality d values, identifying the optimal neighborhood k and intrinsic dimensionality d value for each method. A comparison of classification accuracies reveals that the LTSA method yields superior classification results compared to other manifold learning approaches. The study demonstrates the advantages of manifold learning methods in processing hyperspectral image data, providing an experimental reference for subsequent research on hyperspectral image dimensionality reduction using manifold learning methods.

Causes of recurrence of paediatric inguinal hernia after single-port laparoscopic closure.

PURPOSE: This paper explores the causes of paediatric inguinal hernia (PIH) recurrence after single-port laparoscopic percutaneous extraperitoneal closure (SPLPEC). METHOD: From January 2015 to December 2020, the clinical data of 3480 children with PIHs who underwent SPLPEC were retrospectively reviewed, including 644 children who underwent SPLPEC with a homemade single-hook hernia needle from January 2015 to December 2016 and 2836 children who underwent the SPLPEC with a double-hook hernia needle and hydrodissection from January 2017 to December 2020. There were 39 recurrences (including communicating hydrocele) during the 2-5 years of follow-up. The findings of redo-laparoscopy were recorded and correlated with the revised video of the first operation to analyse the causes of recurrence. RESULT: Thirty-three males and 6 females experienced recurrence, and 8 patients had a unilateral communicating hydrocele. The median time to recurrence was 7.1 months (0-38). There were 20 cases (3.11%) in the single-hook group and 19 cases (0.67%) in the double-hook group. Based on laparoscopic findings, recurrence most probably resulted from multiple factors, including uneven tension of the ligation (10 cases), missing part of the peritoneum (14 cases), loose ligation (8 cases), broken knot (5 cases), and knot reaction (2 cases). All children who underwent repeat SPLPEC were cured by double ligations or reinforcement with medial umbilical ligament. CONCLUSION: The main cause of recurrence is improper ligation. Tension-free and complete PIH ligation are critical to the success of surgery, which requires avoiding the peritoneum skip area and the subcutaneous and muscular tissues. Redo-laparoscopic surgery was suitable for the treatment of recurrent inguinal hernia (RIH). For giant hernias, direct ligation of the internal ring incorporating the medial umbilical ligament (DIRIM) may be needed.

Monitoring of Vegetation Disturbance and Restoration at the Dumping Sites of the Baorixile Open-Pit Mine Based on the LandTrendr Algorithm.

Overstocked dumping sites associated with open-pit coal mining occupy original vegetation areas and cause damage to the environment. The monitoring of vegetation disturbance and restoration at dumping sites is important for the accurate planning of ecological restoration in mining areas. This paper aimed to monitor and assess vegetation disturbance and restoration in the dumping sites of the Baorixile open-pit mine using the LandTrendr algorithm and remote sensing images. Firstly, based on the temporal datasets of Landsat from 1990 to 2021, the boundaries of the dumping sites in the Baorixile open-pit mine in Hulunbuir city were extracted. Secondly, the LandTrendr algorithm was used to identify the initial time and duration of vegetation disturbance and restoration, while the Normalized Difference Vegetation Index (NDVI) was used as the input parameter for the LandTrendr algorithm. Thirdly, the vegetation restoration effect at the dumping sites was monitored and analyzed from both temporal and spatial perspectives. The results showed that the dumping sites of the Baorixile open-pit mine were disturbed sharply by the mining activities. The North dumping site, the South dumping site, and the East dumping site (hereinafter referred to as the North site, the South site, and the East site) were established in 1999, 2006, and 2010, respectively. The restored areas were mainly concentrated in the South site, the East site, and the northwest of the North site. The average restoration intensity in the North site, South site, and East site was 0.515, 0.489, and 0.451, respectively, and the average disturbance intensity was 0.371, 0.398, and 0.320, respectively. The average restoration intensity in the three dumping sites was greater than the average disturbance intensity. This study demonstrates that the combination of temporal remote sensing images and the LandTrendr algorithm can follow the vegetation restoration process of an open-pit mine clearly and can be used to monitor the progress and quality of ecological restoration projects such as vegetation restoration in mining areas. It provides important data and support for accurate ecological restoration in mining areas.

Laparoscopic surgery for stage III neuroblastoma: A case report.

Laparoscopic surgery for malignant solid tumors is still in the stage of clinical exploration. Neuroblastoma is a common solid tumor in children. The present study discussed significance and feasibility of complete resection of stage III neuroblastoma by laparoscopic surgery and its safety and effectiveness was compared with traditional surgery. For children suffering from neuroblastoma with large tumor volume and vascular invasion, preoperative chemotherapy can be given and minimally invasive laparoscopic surgery can be one option to be considered when the tumor volume is <6 cm. During the operation, the tumor tissue can be removed by segmental resection and the removal of as much tumor tissue as possible is an important factor in improving the prognosis. Laparoscopic minimally invasive surgery is associated with minimal surgical trauma and quick recovery of patients, and children can receive postoperative chemotherapy as early as possible, which is conducive to good recovery. Basically, the prerequisite and requirements for performing this operation are professional laparoscopic skills and an experienced team.

Inhibited Maternal Bone Resorption Suppress Fetal Rat Bone Development During Pregnancy.

OBJECTIVE: To determine the relationship between maternal bone resorption and bone development in fetuses. METHODS: Female SD rats were injected with either fluorescent calcium indicator calcein alone or together with tetracycline 1 week before pregnancy, followed by fluorescence detection in fetal tibias 21 days post-treatment. Alendronate was subsequently administered to pregnant rats to inhibit maternal bone resorption, while maternal bone turnover and fetal bone development were both examined. RESULTS: The maternal fluorescent labeled calcium before pregnancy was found in the fetal tibia. This indicated that the calcium of maternal bones may be released into the maternal circulation through high bone resorption during pregnancy, thereby participating in the fetal bone development. Bone histomorphometry and serum biomarker results showed that Alendronate significantly inhibited maternal bone resorption in pregnant rats when compared to normal pregnant rats. Moreover, the body weight, bone mass, and bone length of the fetuses in the Alendronate group were significantly decreased; while no apparent abnormality in placental morphology was observed. The above results implied that when maternal bone resorption is suppressed, the development of the fetal bone shall also be suppressed. CONCLUSION: Calcium in the maternal bone is released into the maternal circulation through bone resorption during pregnancy which represents an important material source in fetal bone development. Therefore, high bone turnover during pregnancy is essential for mammalian embryonic bone development.

[Effects of aldosterone on osteoblast proliferation, differentiation and osteogenic gene expressions in vitro].

OBJECTIVE: To study the effect of aldosterone on cell proliferation, alkaline phosphatase (AKP) activity and osteogenic gene expression in rat osteoblasts and explore the mechanisms. METHODS: Osteoblasts isolated from the skull of neonatal SD rats by enzyme digestion were cultured and treated with different concentrations of aldosterone. The cell proliferation and AKP activity were evaluated using CCK-8 assay kit and AKP assay kit, respectively. The effects of aldosterone on mRNA and protein expressions of the osteogenic genes and epithelial sodium channel (ENaC) gene were investigated using semi-quantitative PCR and Western blotting. RESULTS: Compared with the control cells, the cells treated with 0.01-1.0 µmol/L aldosterone showed obviously enhanced proliferation while lower (1×10-3 µmol/L) or higher (10 µmol/L) concentrations of aldosterone did not significantly affect the cell proliferation. Aldosterone within the concentration range of 1×10-3 to 10 µmol/L did not cause significant changes in AKP activity in the osteoblasts. Treatment with 0.01 to 1.0 µmol/L aldosterone significantly upregulated the expressions of the osteogenic genes and α-ENaC gene at both the mRNA and protein levels. CONCLUSION: Aldosterone within the concentration range of 0.01-1.0 µmol/L stimulates the proliferation and osteogenic gene expressions and enhances α-ENaC gene expression in rat osteoblasts in vitro, suggesting the possibility that ENaC participates in aldosterone-mediated regulation of osteoblast functions.

Baicalin positively regulates osteoclast function by activating MAPK/Mitf signalling.

Activation of osteoblasts in bone formation and osteoclasts in bone resorption is important during the bone fracture healing process. There has been a long interest in identifying and developing a natural therapy for bone fracture healing. In this study, we investigated the regulation of osteoclast differentiation by baicalin, which is a natural molecule extracted from Eucommiaulmoides (small tree native to China). It was determined that baicalin enhanced osteoclast maturation and bone resorption activity in a dose-dependent manner. Moreover, this involves the activation of MAPK, increased Mitf nuclear translocation and up-regulation of downstream osteoclast-related target genes expression. The baicalin-induced effect on osteoclast differentiation can be mimicked by specific inhibitors of p-ERK (U0126) and the Mitf-specific siRNA, respectively. Protein-ligand docking prediction identified that baicalin might bind to RANK, which is the upstream receptor of p-ERK/Mitf signalling in osteoclasts. This indicated that RANK might be the binding target of baicalin. In sum, our findings revealed baicalin increased osteoclast maturation and function via p-ERK/Mitf signalling. In addition, the results suggest that baicalin can potentially be used as a natural product for the treatment of bone fracture.

Ferulic acid induces proliferation and differentiation of rat osteoblasts in vitro through cGMP/PKGII/ENaC signaling.

Ferulic acid (FA) is an active component of the traditional Chinese herb Angelica sinensis. Numerous health benefits have been attributed to FA, but few studies have investigated the effects of FA on osteoblasts (Obs). Our work studied the effects of FA on proliferation, differentiation, and mineralization of rat calvarial Obs and examined the signaling pathways involved. Cell proliferation and differentiation were evaluated by Cell Counting Kit-8 (CCK-8) and alkaline phosphatase (ALP) assay kit, respectively. Cyclic guanosine monophosphate (cGMP)-dependent protein kinase II (PKGII) expression was silenced by small interfering RNA (siRNA). The mRNA expression was investigated by semi-quantitative PCR. FA (40-2560 µM) promoted Ob proliferation and differentiation; at 40-640 µM, FA stimulated calcified nodule formation and increased the expression of osteogenic genes encoding osteopontin and collagen-l. FA (40-2560 µM) increased cGMP levels in Obs and upregulated the expression of PKGII, EnaCα, and ENaCγ mRNAs. Downregulated ENaCα mRNA expression in Obs transfected with the siRNA for PKGII was reversed when FA was introduced into Obs. These results demonstrated that FA promoted proliferation, differentiation, and mineralization of Obs in vitro, and enhanced osteogenic genes expression partly through the cGMP-PKGII-ENaC signaling pathway.

[Role of epithelial sodium channel in rat osteoclast differentiation and bone resorption].

OBJECTIVE: To explore the role of epithelial sodium channel (ENaC) in regulating the functional activity of osteoclasts. METHODS: Multinucleated osteoclasts were obtained by inducing the differentiation of rat bone marrow cells with macrophage colony-stimulating factor (M-CSF) and RANKL. The osteoclasts were exposed to different concentrations of the ENaC inhibitor amiloride, and the expression of ENaC on osteoclasts was examined using immunofluorescence technique. The osteoclasts were identified with tartrate-resistant acid phosphatase (TRAP) staining, and the positive cells were incubated with fresh bovine femoral bone slices and the number of bone absorption pits was counted by computer-aided image processing. RT-PCR was performed to analyze the expression of cathepsin K in the osteoclasts. RESULTS: s Exposure to different concentrations of amiloride significantly inhibited the expression of ENaC and reduced the number of TRAP-positive osteoclasts. Exposure of the osteoclasts to amiloride also reduced the number of bone resorption pits on bone slices and the expression of osteoclast-specific gene cathepsin K. CONCLUSION: s ENaC may participate in the regulation of osteoclast differentiation and bone resorption, suggesting its role in functional regulation of the osteoclasts and a possibly new signaling pathway related with ENaC regulation for modulating bone metabolism.

Critical role of myeloid differentiation factor 88 in necrotizing enterocolitis.

BACKGROUND: The importance of toll-like receptor 4 in necrotizing enterocolitis (NEC) has been intensively studied, but its downstream signaling and the potential regulatory mechanisms remain unidentified. Our study focused on the role of myeloid differentiation factor 88 (MyD88), the first downstream adaptor of toll-like receptor 4 inflammatory and apoptotic signaling in the pathogenesis of NEC. METHODS: MyD88 knockout (MyD88(-/-)-Ko) mice and lentivirus-mediated stable MyD88-knockdown cell line (IEC-6) were used. NEC was induced by formula gavage, cold, hypoxia, combined with lipopolysaccharide (LPS) in vivo, or LPS stimulation in vitro. NEC was evaluated by histology and multiple inflammatory cytokines. Enterocyte apoptosis was evaluated by terminal-deoxynucleoitidyl transferase-mediated nick end labeling (TUNEL) or Annexin analysis. Inflammatory or apoptotic molecules including NF-κB, Toll/IL-1R domain-containing adaptor-inducing IFN-ß, interferon regulatory factor 3, Bax, Bcl-2, and caspases were examined by quantitative real-time PCR (qRT-PCR). RESULTS: In the MyD88-Ko group, NEC severity and intestinal enterocyte apoptosis rate were reduced, the expression of NF-κB, caspases, and Bax, were all downregulated, while Toll/IL-1R domain-containing adaptor-inducing IFN-ß and were upregulated, and antiapoptotic gene Bcl-2 remained stable. Cytokine levels of interleukin (IL)-6, IL-1ß, and tumor necrosis factor-α (TNF-α) were also all decreased. CONCLUSION: MyD88-dependent signaling is the prevailing inflammatory and apoptotic signaling in toll-like receptor 4 downstream signaling; MyD88-Ko resulted in reduced inflammatory severity and apoptosis, though MyD88-independent signaling can also be activated, but is of less dominant for the development of NEC.

Epithelial sodium channel enhanced osteogenesis via cGMP/PKGII/ENaC signaling in rat osteoblast.

The amiloride-sensitive epithelial sodium channel (ENaC) is a major contributor to intracellular sodium homeostasis. In addition to epithelial cells, osteoblasts (Obs) express functional ENaCs. Moreover, a correlation between bone Na content and bone disease has been reported, suggesting that ENaC-mediated Na(+) regulation may influence osteogenesis. Obs were isolated and cultured by enzyme digestion. Cell proliferation and differentiation were evaluated by WST-8 assay kit and AKP assay kit respectively. PKGII expression was silenced by siRNA. The mRNA expression was investigated by semi-quantitative PCR and the protein expression was determined by Western-blot. The cell-permeable cGMP analog 8-(4-chlorophenylthio)-cGMP (8-pCPT-cGMP) increased α-ENaC channel expression in primary rat Obs as indicated by RT-PCR. In addition, 8-pCPT-cGMP stimulation enhanced expression of the mRNA encoding cGMP-dependent protein kinases II (PKGII). The cGMP analog also promoted osteoblast proliferation, differentiation and induced the expression of several osteogenic genes, including core binding factor al, osteocalcin, alkaline phosphatase, collagen type I, and osteopontin. Furthermore, the expression of α-ENaC, the main functional subunit of ENaC, was reduced when a small interfering RNA specific for PKGII was introduced into Obs. Treatment with 8-pCPT-cGMP in cells transfected with the siRNA for PKGII partially reversed downregulated α-ENaC mRNA expression. Our results suggest that 8-pCPT-cGMP stimulates proliferation, differentiation, and osteogenic gene expression in Obs through cGMP/PKGII-dependent regulation of ENaC channel expression. The cGMP/PKGII signaling pathway is a potential target for pharmaceutical interventions to treat metabolic bone diseases.

[Effects of drug serum of plantaginis semen on bone formation function of rat osteoblast in vitro].

OBJECTIVE: To study the influence of Plantaginis Semen on cell proliferation, differentiation and function of rat osteoblasts, and investigate the regulation effects of rat osteoblast epithelial sodium channel (ENaC) on bone formation. METHODS: The animal serum was prepared by serum pharmacology means. The cells were got by separating and inducing the SD neonatal rat's skull bone. Cell proliferation and differentiation were evaluated by CCK-8 assay kit and AKP assay kit respectively. Regulation effects on mRNA expression of ENaC and osteogenesis gene were investigated by semi-quantitative PCR. RESULTS: Plantaginis Semen stimulated the osteoblasts proliferation and differentiation,the difference between treatment group and control group had statistical significance (P < 0.01) in a dose-dependent manner. The effects of Plantaginis Semen serum on alpha-ENaC gene expression paralleled those on osteogenic gene (OC, ALP, OP) expression level. CONCLUSION: Plantaginis Semen stimulates proliferation, differentiation and the mRNA expression of ENaC and osteogenesis gene in rat osteoblasts. Our results suggest that ENaC participate in the effects of Plantaginis Semen serum on osteoblast bone formation. Regulation of ENaC channel expression and function may provide a new clue for research on treatment of osteoporosis with traditional Chinese medicine.

The influence of dietary sodium on bone development in growing rats.

The present study investigated the effects of dietary sodium on bone growth in young rats. Five-week-old rats were fed one of three different diets for 60 days: low sodium (NaCl, 0.32 g/kg diet), normal sodium (NaCl, 2.6 g/kg) and high sodium (NaCl, 20 g/kg). The proximal tibial metaphysis (PTM), the fifth lumbar vertebra (LV5) and the middle part of the tibia shaft (TX) were analysed by bone histomorphometry. The expression of three osteogenesis genes, Runx2, osteopontin and osteocalcin, was determined by RT-PCR in bone samples from the skull. In both the PTM and LV5, trabecular area and thickness were increased by the low-sodium diet, while the high-sodium diet decreased trabecular area in LV5. Dynamic data revealed that sodium restriction increased bone formation parameters in the PTM and LV5, but decreased bone resorption in LV5. In TX, endosteal bone formation was enhanced by the low-sodium diet and depressed by the high-sodium diet compared to the normal sodium group. But there were no statistically changes in the cortical bone area of TX. Low-sodium intake significantly enhanced the expression of all three osteogenesis genes compared to the normal sodium group, while high-sodium intake suppressed osteogenic gene expression. Our results suggest that sodium restriction in growing rats promotes bone development by influencing both bone formation and resorption.

[Establishment of a tight tetracycline-controlled HCV-C double transgenic mouse model].

OBJECTIVE: To develop a tight tetracycline-controlled HCV-C double transgenic mouse model. METHODS: By crossbreeding of ApoE-rtTA-tTS transgenic mice with TRE-HCV-C transgenic mice, the double transgenic mice were produced in the F1 generation. The presence of HCV-C and tTS gene in the F1 generation was confirmed by PCR, followed by further identification and quantification of the transgene using Southern blot hybridization. The expression of HCV-C in the liver of the mouse model was detected immunohistochemically. RESULTS AND CONCLUSION: Two transgenic mice were obtained, which contained ApoE-rtTA-tTS and TRE-HCV-C genes in the genome. Five founders contained HCV-C gene as confirmed by PCR and Southern blot hybridization. The tight tetracycline-controlled system may facilitate further study of HCV-C gene expression and gene therapy of hepatic cellular carcinoma.