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1.
Heliyon ; 10(5): e27191, 2024 Mar 15.
Article in English | MEDLINE | ID: mdl-38468936

ABSTRACT

Backgrounds: This study aims to explore the clinical value of P4HA2 (prolyl 4-hydroxylase subunit alpha 2) in Osteosarcoma (OSC), and assess its potential to provide directions and clues for the practice of precision nursing. Methods: The GSE73166 and GSE16088 datasets were used to explore the P4HA2 expression in OSC. We then used the clinical data of patients obtaining from TARGET database to assess the prognostic value of P4HA2 in OSC. We also evaluated the predictive value of prognostic model based on P4HA2-related genes. Further, GSEA analysis was performed to explore related pathways. Results: The P4HA2 mRNA expression was higher in OSC than that in normal tissues and other bone cancer samples. Survival analysis found that P4HA2 high expression caused poor overall survival (OS) of patients with OSC and P4HA2 presented a favorable performance for predicting OS. Specifically, P4HA2 high expression statistically influenced the OS of patients with age≥15 years old and those with or without metastasis. Cox regression analysis indicated the independent prognostic value of P4HA2 in OSC, and nomogram analysis revealed its significant contribution to the survival probability of patients. We further established a prognostic model based on P4HA2-related genes, finding that prognostic model had a good prediction ability on OS. These results supported the clinical significance of P4HA2 in OSC. GSEA analysis suggested that P4HA2 was significantly related to the MAPK signaling pathway. In addition, P4HA2-associated natural killer cell-mediated cytotoxicity and T cell receptor signaling pathway were also predicted. Conclusions: This study revealed that P4HA2 can serve as an important prognostic biomarker for OSC patients, and it may become a promising therapeutic target in OSC treatment.

2.
Neural Netw ; 172: 106151, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38301339

ABSTRACT

Representation learning on temporal interaction graphs (TIG) aims to model complex networks with the dynamic evolution of interactions on a wide range of web and social graph applications. However, most existing works on TIG either (a) rely on discretely updated node embeddings merely when an interaction occurs that fail to capture the continuous evolution of embedding trajectories of nodes, or (b) overlook the rich temporal patterns hidden in the ever-changing graph data that presumably lead to sub-optimal models. In this paper, we propose a two-module framework named ConTIG, a novel representation learning method on TIG that captures the continuous dynamic evolution of node embedding trajectories. With two essential modules, our model exploits three-fold factors in dynamic networks including latest interaction, neighbor features, and inherent characteristics. In the first update module, we employ a continuous inference block to learn the nodes' state trajectories from time-adjacent interaction patterns using ordinary differential equations. In the second transform module, we introduce a self-attention mechanism to predict future node embeddings by aggregating historical temporal interaction information. Experiment results demonstrate the superiority of ConTIG on temporal link prediction, temporal node recommendation, and dynamic node classification tasks of four datasets compared with a range of state-of-the-art baselines, especially for long-interval interaction prediction.


Subject(s)
Machine Learning
3.
J Environ Sci (China) ; 139: 281-292, 2024 May.
Article in English | MEDLINE | ID: mdl-38105055

ABSTRACT

Realizing campus sustainability requires the environmental-friendly and economical treatment of tremendous fallen leaves. Producing fallen leaf biochar at a low temperature is a candidate approach. In this study, six common types of fallen leaves on the campus were pyrolyzed at 300 °C. The obtained biochars were characterized and the adsorption mechanisms of lead (Pb) by the fallen leaf biochars were investigated. The adsorption capacity of leaf biochar for Pb was relatively high, up to 209 mg/g (Yulania denudata leaf biochar). Adsorption of Pb onto active sites was the rate-limiting step for most leaf biochars. But for Platanus leaf biochar, intraparticle diffusion of Pb2+ dominated owing to the lowest adsorption capacity. However, the highest exchangeable Pb fraction (27%) indicated its potential for removing aqueous Pb2+. Ginkgo and Prunus cerasifera leaf biochar immobilized Pb by surface complexation and precipitation as lead oxalate. Hence, they were suitable for soil heavy metal remediation. This study shed the light on the sustainable utilization of campus fallen leaves and the application of fallen leaf biochars in heavy metal remediation.


Subject(s)
Lead , Metals, Heavy , Temperature , Pyrolysis , Charcoal/chemistry , Plant Leaves , Adsorption
4.
Article in English | MEDLINE | ID: mdl-37159978

ABSTRACT

Qing Fei Yi Huo tablets (QFYHT) can relieve the clinical symptoms of acute bronchitis, and is widely prescribed in China. However, the quality standard of QFTHT lacks quantitative assessment. Therefore, it is crucial to develop an effective method for the extraction and analyses of its bioactive components.This study aimed to optimize the ultrasonic extraction of QFYHT and establish a method for the simultaneous quantification of 15 components. Box-Behnken Design (BBD) experiment was employed with three factors (solvent volume, extraction time and ultrasonic power) to optimize the extraction conditions, and the total content of 15 components was measured by high-performance liquid chromatography-diode array detector (HPLC-DAD) method. The total extracted content of 15 components was the highest when 100% methanol was used as the solvent, and the solvent volume was 22 mL, extraction time was 30 min and ultrasonic power was 350 w. The 15 components showed a good linear relationship (r ≥ 0.9998) within a concentration range. The precision, stability and repeatability of this method were satisfactory, and the average recovery rates ranged from 98.08% ∼ 102.87%. These findings demonstrate that optimization of extraction conditions by RSM can significantly improve the ultrasonic extraction rate of the 15 bioactive components of QFYHT. The quantification method is simple, accurate, reliable and practical, and can provide reference for improving the quality control of QFYHT.


Subject(s)
Methanol , Plant Extracts , Solvents , Chromatography, High Pressure Liquid/methods , Ultrasonics
5.
Chemosphere ; 327: 138477, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36966928

ABSTRACT

The long-term effectiveness of heavy metal immobilization is always a concern. This study proposes a completely novel approach to enhance the stability of heavy metals by combined biochar and microbial induced carbonate precipitation (MICP) technology, to create a "surface barrier" of CaCO3 layer on biochar after lead (Pb2+) immobilization. Aqueous sorption studies and chemical and micro-structure tests were used to verify the feasibility. Rice straw biochar (RSB700) was produced at 700 °C, which shows high immobilization capacity of Pb2+ (maximum of 118 mg g-1). But the stable fraction only accounts for 4.8% of the total immobilized Pb2+ on biochar. After MICP treatment, the stable fraction of Pb2+ significantly increased to a maximum of 92.5%. Microstructural tests confirm the formation of CaCO3 layer on biochar. The CaCO3 species are predominantly calcite and vaterite. Higher Ca2+ and urea concentrations in cementation solution resulted in higher CaCO3 yield but lower Ca2+ utilization efficiency. The main mechanism of the "surface barrier" to enhance Pb2+ stability on biochar was likely the encapsulation effect: it physically blocked the contact between acids and Pb2+ on biochar, and chemically buffer the acidic attack from the environment. The performance of the "surface barrier" depends on both the yield of CaCO3 and their distribution uniformity on biochar's surface. This study shed lights on the potential application of the "surface barrier" strategy combining biochar and MICP technologies for enhanced heavy metal immobilization.


Subject(s)
Environmental Restoration and Remediation , Metals, Heavy , Soil Pollutants , Lead , Soil Pollutants/analysis , Charcoal/chemistry , Metals, Heavy/analysis , Calcium Carbonate , Soil/chemistry
6.
Pak J Pharm Sci ; 35(4): 1095-1101, 2022 Jul.
Article in English | MEDLINE | ID: mdl-36008907

ABSTRACT

Rhei Radix et Rhizoma formula granule (RRFG) , Winy Rhei Radix et Rhizoma formula granule(WRFG) and Rhubarb charcoal formula granules (RCFG) are the three most popular and effective formula granules of rhubarb in China and anthraquinone components are their main active ingredients. In order to discuss the difference in anthraquinone components of these three drugs, a simultaneous quantitative analysis method of multicomponents by single-marker (QAMS) was developed. Emodin was chosed as the internal reference standard, the relative correction factors (RCFs) of aloe-emodin, rhein, chrysophanol and physcion were established and the contents of the four components were calculated based on the RCFs, respectively. Meanwhile, the contents of these components was determined by external standard method (ESM) and compared with QAMS to verify its rationality, feasibility and repeatability. The results showed that there were no significant difference between QAMS and ESM (RSDs≤2.26%). The contents of anthraquinone components showed a wide variation in these three drugs. All of 5 components were higher in RRFG than that in the others and RCFG had the lowest content. This method was successfully applied for the evaluation on difference of these drugs and the wide variation in anthraquinone components indicated there were different pharmacodynamic basis.


Subject(s)
Drugs, Chinese Herbal , Emodin , Rheum , Anthraquinones , Chromatography, High Pressure Liquid/methods , Rhizome
7.
Cell Death Discov ; 7(1): 307, 2021 Oct 22.
Article in English | MEDLINE | ID: mdl-34686652

ABSTRACT

Tumor-associated macrophages (TAMs) are known to participate in osteosarcoma (OS) progression. As demonstrated in our previous research, miR-363 played a tumor inhibitory effect in OS cells via lowering the PDZ domain containing 2 (PDZD2) expression. The regulatory roles of TAMs on miR-363/PDZD2 and the internal mechanism relating to long noncoding RNA p53 upregulated regulator of P53 levels (lncRNA PURPL) are examined in this study. TAM-like macrophages were formed by inducing CD14+ peripheral blood mononuclear cells (PBMCs). The TAMs migration was detected after MG-63 cells transfected with miR-363 mimics or inhibitors. We then analyzed the regulatory activity of PURPL on miR-363 expression. We also tested the influences of PURPL overexpression/knockdown on MG-63 cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT), as well as TAMs migration. Silence in PDZD2 expression was used to confirm the effects of PURPL on MG-63 cells. We successfully induced TAM-like macrophages. MG-63 cells transfecting miR-363 mimics suppressed TAMs migration while transfecting a converse effect was seen in miR-363 inhibitor. TAMs raised PURPL expression in MG-63 cells, which was an upstream regulator of miR-363. Along with TAMs migration, PURPL overexpression promoted MG-63 cell proliferation, migration, invasion, and EMT. An opposite influence was seen due to the PURPL knockdown. The silence of PDZD2 weakened the influences of PURPL overexpression on MG-63 cells and TAMs migration. On modulating the PURPL/miR-363/PDZD2 axis, TAMs-promoted OS development might be achieved.

8.
Scanning ; 2020: 5642124, 2020.
Article in English | MEDLINE | ID: mdl-33425091

ABSTRACT

The wide application of superhydrophobic materials is mainly hindered by the poor mechanical robustness and complicated preparation method. To overcome these problems, we tried to make a combination of hierarchical and self-similar structure by the means of a simple spraying method. By adding nanofiller (carbon nanotube) and microfiller (graphite powder and expanded graphite), the hierarchical structure was constructed. By further doping the fillers in the commercial asphalt uniformly, the self-similar structure was prepared. Based on the aforementioned work, the as-prepared sample could withstand the sandpaper abrasion for 12.00 m under 4.90 kPa. Moreover, this superhydrophobic coating demonstrated good conductivity, superior self-cleaning property, and excellent corrosion resistance. The integration of conductivity with the superhydrophobicity might open new avenues for ground grid applications.

9.
Chemosphere ; 235: 825-831, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31284130

ABSTRACT

Rice husk is a common agricultural waste. The utilization of rice husk biochar depends on the characteristics of biochar and its interaction mechanisms with heavy metals. In the present study, rice husk biochars at three different temperatures 300, 500, and 700 °C were produced (RH300, RH500, and RH700). The characteristics of these rice husk biochars and their interaction mechanisms with lead (Pb) were investigated, in order to reveal the potential environmental applications of the biochars. It was observed that the surface area (from 0.632 to 193.149 m2/g) and pH (from 7.13 to 9.80) of the rice husk biochars significantly increased as production temperature rose from 300 to 700 °C, while the number of functional groups (e.g., carboxyl) decreased. The Langmuir maximum removal capacity (Qmax) values for Pb are in the order of RH300 < RH500 < RH700 (14.1, 21.7, and 26.7 mg/g respectively). Although RH300 has the smallest Qmax value, its exchangeable Pb amount is the largest (2.61 versus 0.223-0.377 mg/g), suggesting RH300 may be suitable for water treatment due to the easy separation of immobilized Pb and better recycling usage. The Pb immobilized on RH500 and RH700 was mainly acidic soluble and generally stable. Hydrocerussite is one important form within the acidic soluble fraction. Within the generally stable formation, pyromorphite is a form for the immobilized Pb on the rice husk biochars, particularly for RH500 and RH700. These findings suggest RH500 and RH700 are of promising potential to be applied in soil remediation to immobilize Pb and reduce its environmental risks.


Subject(s)
Lead/chemistry , Water Pollutants, Chemical/chemistry , Water Purification/methods , Agriculture , Carbonates , Charcoal , Lead/analysis , Metals, Heavy/analysis , Oryza , Soil , Temperature , Water Pollutants, Chemical/analysis
10.
Chemosphere ; 233: 149-156, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31173952

ABSTRACT

Based on the "waste-treat-waste" concept, biochars were produced from cadmium (Cd)-contaminated rice straw (CRSBs) at 300, 500, and 700 °C (CRSB300, CRSB500, and CRSB700). The risks of the Cd remaining in CRSBs were evaluated and the optimal biochar pyrolysis temperature for Cd removal was investigated. It was observed that 41% of the total Cd in the raw rice straw was exchangeable, which may pose significant risks to crops and humans. Pyrolyzing at 300 °C did not significantly alter the Cd fractions, while the exchangeable fraction of Cd greatly dropped to 5.79% at 500 °C and further to 2.12% at 700 °C. Increasing the highest pyrolysis temperature resulted in CRSBs with higher pH values, greater surface area, and smaller pore sizes, thus providing more rapid and efficient removal of Cd from aqueous solutions. For Cd removal tests, increasing pyrolysis temperature (300-700 °C) increased the total (24.8-55.1 mg/g) and non-exchangeable (18.9-52.8 mg/g) Cd concentrations immobilized on the CRSBs and significantly decreased the exchangeable Cd fraction (23.7%-4.85%). It is suggested based on the study from aqueous solutions that CRSB700 was the most suitable for the remediation of Cd contaminated soil on site due to the lowest risks of remained Cd from feedstock, fastest and highest Cd removal, and most stable immobilization of Cd.


Subject(s)
Cadmium/isolation & purification , Charcoal , Environmental Pollutants/isolation & purification , Oryza/chemistry , Cadmium/chemistry , Environmental Pollutants/chemistry , Environmental Pollution , Hydrogen-Ion Concentration , Plant Stems/chemistry , Pyrolysis , Risk Factors , Temperature , Water/chemistry
11.
Biosci Rep ; 39(3)2019 03 29.
Article in English | MEDLINE | ID: mdl-30804229

ABSTRACT

Osteoblast-mediated bone formation is a complex process involving various pathways and regulatory factors, including cytokines, growth factors, and hormones. Investigating the regulatory mechanisms behind osteoblast differentiation is important for bone regeneration therapy. miRNAs are known as important regulators, not only in a variety of cellular processes, but also in the pathogenesis of bone diseases. In the present study, we investigated the potential roles of miR-206 during osteoblast differentiation. We report that miR-206 expression was significantly down-regulated in human bone marrow mesenchymal stem cells (BMSCs) at days 7 and 14 during osteogenic induction. Furthermore, miR-206 overexpressing BMSCs showed attenuated alkaline phosphatase (ALP) activity, Alizarin Red staining, and osteocalcin secretion. The mRNA levels of osteogenic markers, Runx2 and Osteopontin (OPN), were significantly down-regulated in miR-206 overexpressing BMSCs. We observed that significantly increased glutamine uptake at days 7 and 14 during the osteogenic induction and inhibition of glutamine metabolism by knocking down glutaminase (GLS)-suppressed osteogenic differentiation of BMSCs. Here, we discover that miR-206 could directly bind to the 3'-UTR region of GLS mRNA, resulting in suppressed GLS expression and glutamine metabolism. Finally, restoration of GLS in miR-206 overexpressing BMSCs led to recovery of glutamine metabolism and osteogenic differentiation. In summary, these results reveal a new insight into the mechanisms of the miR-206-mediated osteogenesis through regulating glutamine metabolism. Our study may contribute to the development of therapeutic agents against bone diseases.


Subject(s)
Bone Marrow Cells/metabolism , Cell Differentiation/genetics , Glutaminase/genetics , Mesenchymal Stem Cells/metabolism , MicroRNAs/genetics , Osteogenesis/genetics , 3' Untranslated Regions/genetics , Cells, Cultured , Gene Expression Regulation , Glutaminase/metabolism , Glutamine/metabolism , Humans , Osteoblasts/cytology , Osteoblasts/metabolism , Osteocalcin/metabolism , Osteopontin/genetics , Osteopontin/metabolism
12.
Sci Total Environ ; 655: 751-758, 2019 Mar 10.
Article in English | MEDLINE | ID: mdl-30476855

ABSTRACT

Production temperature significantly affects biochar properties and consequently the removal mechanisms of heavy metals. In this study, rice straw biochars were produced at 300, 500 and 700 °C (RSB300, RSB500 and RSB700). The influence of production temperature on the adsorption characteristics and removal mechanisms of lead on this set of rice straw biochars were investigated by batch adsorption tests, micro-structural analyses and sequential metal extractions. Biochars produced at higher temperatures had significantly higher pH values and surface areas, resulting in higher metal removal capacities and faster uptake kinetics. Precipitation was a key mechanism for lead removal from solution for all biochars: lead oxalate was precipitated on RSB300, and hydrocerussite was precipitated on RSB500 and RSB700. The immobilized lead fraction on the biochars could be divided into exchangeable, acid soluble and non-available fractions. RSB300 had 11.34% of the total immobilized Pb attributed to the exchangeable fraction, whereas for RSB500 and RSB700, it was <1%. Immobilized Pb on RSB500 and RSB700 was almost exclusively attributable to the acid soluble and non-available fractions (>99%). Based on our results, RSB500 and RSB700 are likely much more appropriate for soil remediation of Pb as compared with RSB300.


Subject(s)
Charcoal/chemistry , Environmental Restoration and Remediation/methods , Hot Temperature , Lead/isolation & purification , Oryza/chemistry , Soil Pollutants/isolation & purification , Adsorption , Biological Availability , Fractional Precipitation , Hydrogen-Ion Concentration , Kinetics , Surface Properties
13.
Brain Behav ; 9(1): e01176, 2019 01.
Article in English | MEDLINE | ID: mdl-30548434

ABSTRACT

OBJECTIVE: Brain injury is implicated in pathogenesis of postoperative delirium (POD) and cognitive dysfunction (POCD). S100A12 is involved in inflammatory process and is recently known as a biomarker for brain injury. Herein, we clarified whether serum S100A12 levels are related to POD and POCD after hip fracture surgery in elderly patients. MATERIALS AND METHODS: In this prospective, observational study, we gauged S100A12 levels in preoperative and postoperative serum from 186 patients and serum from 186 controls. Patients were categorized according to the presence of POD and POCD. RESULTS: Postoperative, but not preoperative serum S100A12 levels were significantly higher in patients than in controls. There was a positive and independent correlation between postoperative C-reactive protein and S100A12 levels (t = 8.797, p < 0.001). Postoperative S10012 levels and age were independently associated with the risk of developing POD (S100A12 levels: odds ratio [OR] = 1.166, 95% confidence interval [CI] = 1.045-2.087, p = 0.001; age: OR = 1.243, 95% CI = 1.073-1.419, p = 0.012) and POCD (S100A12: OR = 1.157, 95% CI = 1.030-1.986, p = 0.003; age: OR = 1.228, 95% CI = 1.054-1.387, p = 0.014). In terms of area under receiver operating characteristic curve, postoperative S100A12 levels had a higher predictive ability than age and their combination dramatically exceeded that of each one alone. CONCLUSIONS: Postoperative elevated serum S100A12 levels have a strong relation to inflammation and are associated independently with the development of POD and POCD, substantializing serum S100A12 as a potential biomarker for predicting POD and POCD in elderly patients undergoing hip fracture surgery.


Subject(s)
Cognitive Dysfunction , Delirium , Fracture Fixation/adverse effects , Hip Fractures/surgery , Inflammation , S100A12 Protein/blood , Aged , C-Reactive Protein/analysis , Cognitive Dysfunction/blood , Cognitive Dysfunction/diagnosis , Cognitive Dysfunction/etiology , Delirium/blood , Delirium/diagnosis , Delirium/etiology , Female , Humans , Inflammation/blood , Inflammation/etiology , Male , Perioperative Period , Postoperative Complications/blood , Postoperative Complications/diagnosis , Predictive Value of Tests , Prospective Studies
14.
Sensors (Basel) ; 18(2)2018 Jan 26.
Article in English | MEDLINE | ID: mdl-29373549

ABSTRACT

Integrated navigation algorithms under the grid frame have been proposed based on the Kalman filter (KF) to solve the problem of navigation in some special regions. However, in the existing study of grid strapdown inertial navigation system (SINS)/Doppler velocity log (DVL) integrated navigation algorithms, the Earth models of the filter dynamic model and the SINS mechanization are not unified. Besides, traditional integrated systems with the KF based correction scheme are susceptible to measurement errors, which would decrease the accuracy and robustness of the system. In this paper, an adaptive robust Kalman filter (ARKF) based hybrid-correction grid SINS/DVL integrated navigation algorithm is designed with the unified reference ellipsoid Earth model to improve the navigation accuracy in middle-high latitude regions for marine application. Firstly, to unify the Earth models, the mechanization of grid SINS is introduced and the error equations are derived based on the same reference ellipsoid Earth model. Then, a more accurate grid SINS/DVL filter model is designed according to the new error equations. Finally, a hybrid-correction scheme based on the ARKF is proposed to resist the effect of measurement errors. Simulation and experiment results show that, compared with the traditional algorithms, the proposed navigation algorithm can effectively improve the navigation performance in middle-high latitude regions by the unified Earth models and the ARKF based hybrid-correction scheme.

15.
Drug Des Devel Ther ; 9: 5925-32, 2015.
Article in English | MEDLINE | ID: mdl-26604690

ABSTRACT

BACKGROUND: The efficacy of ifosfamide-based chemotherapy in the treatment of osteosarcoma has been investigated; however, results are inconsistent. Therefore, we reviewed the relevant studies and conducted a meta-analysis to assess the efficacy of ifosfamide-based chemotherapy in patients with osteosarcoma. METHODS: A systematic literature search on PubMed, Embase, and Web of Science databases was performed. Eligible studies were clinical trials of patients with osteosarcoma who received ifosfamide-based chemotherapy. Hazard ratios (HRs) were pooled to compare event-free survival (EFS) and overall survival (OS). Risk ratios (RRs) were pooled to compare good histologic response rates and adverse event incidence. Meta-analysis was performed using a fixed-effects model or a random-effects model according to heterogeneity. RESULTS: A total of seven randomized controlled trials were included in this meta-analysis. Pooled results showed that ifosfamide-based chemotherapy significantly improved EFS (HR=0.72, 95% confidence interval [CI]: 0.63, 0.82; P=0.000) and OS (HR=0.83, 95% CI: 0.70, 0.99; P=0.034); furthermore, this form of chemotherapy increased good histologic response rate (RR=1.27, 95% CI: 1.10, 1.46; P=0.001). In addition, patients in the ifosfamide group exhibited a significantly higher incidence of fever (RR=2.23, 95% CI: 1.42, 3.50; P=0.000) and required more frequent platelet transfusion (RR=1.92, 95% CI: 1.23, 3.01; P=0.004). CONCLUSION: This meta-analysis confirmed that ifosfamide-based chemotherapy can significantly improve EFS and OS; this chemotherapy can also increase good histologic response rate in patients with osteosarcoma. However, evidence may be limited by potential biases and confounders. Thus, large-scale well-designed randomized controlled trials are needed to verify current findings.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Bone Neoplasms/drug therapy , Osteosarcoma/drug therapy , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Bone Neoplasms/pathology , Disease-Free Survival , Humans , Ifosfamide/administration & dosage , Osteosarcoma/pathology , Randomized Controlled Trials as Topic , Survival Rate
16.
ScientificWorldJournal ; 2014: 294513, 2014.
Article in English | MEDLINE | ID: mdl-25097874

ABSTRACT

Computer-aided process planning (CAPP) is an important interface between computer-aided design (CAD) and computer-aided manufacturing (CAM) in computer-integrated manufacturing environments (CIMs). In this paper, process planning problem is described based on a weighted graph, and an ant colony optimization (ACO) approach is improved to deal with it effectively. The weighted graph consists of nodes, directed arcs, and undirected arcs, which denote operations, precedence constraints among operation, and the possible visited path among operations, respectively. Ant colony goes through the necessary nodes on the graph to achieve the optimal solution with the objective of minimizing total production costs (TPCs). A pheromone updating strategy proposed in this paper is incorporated in the standard ACO, which includes Global Update Rule and Local Update Rule. A simple method by controlling the repeated number of the same process plans is designed to avoid the local convergence. A case has been carried out to study the influence of various parameters of ACO on the system performance. Extensive comparative experiments have been carried out to validate the feasibility and efficiency of the proposed approach.


Subject(s)
Computer Simulation , Algorithms
17.
ScientificWorldJournal ; 2014: 271895, 2014.
Article in English | MEDLINE | ID: mdl-24995355

ABSTRACT

The complex process planning problem is modeled as a combinatorial optimization problem with constraints in this paper. An ant colony optimization (ACO) approach has been developed to deal with process planning problem by simultaneously considering activities such as sequencing operations, selecting manufacturing resources, and determining setup plans to achieve the optimal process plan. A weighted directed graph is conducted to describe the operations, precedence constraints between operations, and the possible visited path between operation nodes. A representation of process plan is described based on the weighted directed graph. Ant colony goes through the necessary nodes on the graph to achieve the optimal solution with the objective of minimizing total production costs (TPC). Two cases have been carried out to study the influence of various parameters of ACO on the system performance. Extensive comparative experiments have been conducted to demonstrate the feasibility and efficiency of the proposed approach.


Subject(s)
Algorithms , Computer Graphics , Numerical Analysis, Computer-Assisted , Animals , Ants , Computer Graphics/instrumentation , Numerical Analysis, Computer-Assisted/instrumentation
18.
Zhongguo Gu Shang ; 22(3): 244-6, 2009 Mar.
Article in Chinese | MEDLINE | ID: mdl-19366126

ABSTRACT

Bone transplantation is widely used in orthopaedics, and allograft bone transplantation is being more and more emphasized. In this article, the allograft bone combined with growth factors transplantation for repairing bone defects were reviewed. Moreover, the way to compound many growth factors and other material is the tendency of allogenic bone grafting, which enhance the opportunity of success in bone transplanting.


Subject(s)
Bone Transplantation , Intercellular Signaling Peptides and Proteins/therapeutic use , Bone Morphogenetic Proteins/therapeutic use , Fibroblast Growth Factor 2/therapeutic use , Humans , Platelet-Derived Growth Factor/therapeutic use , Transforming Growth Factor beta/therapeutic use , Transplantation, Homologous , Vascular Endothelial Growth Factor A/therapeutic use
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