期刊文献+
共找到29篇文章
< 1 2 >
每页显示 20 50 100
Effect of demineralization on pyrolysis characteristics of LPS coal based on its chemical structure 被引量:1
1
作者 Lin Qian Jinkai Xue +3 位作者 Chao Tao Chao Ma Xiaopeng Jiang Feiqiang Guo 《International Journal of Coal Science & Technology》 EI CAS CSCD 2023年第2期181-195,共15页
The critical issue in developing mature Oxy-Coal Combustion Steam System technology could be the reactivity of deminer-alized coal which,is closely related to its chemical structure.The chemical structures of Liupansh... The critical issue in developing mature Oxy-Coal Combustion Steam System technology could be the reactivity of deminer-alized coal which,is closely related to its chemical structure.The chemical structures of Liupanshui raw coal(LPS-R)and Liupanshui demineralized coal(LPS-D)were analyzed by FTIR and solid-state 13C-NMR.The pyrolysis experiments were carried out by TG,and the pyrolysis kinetics was analyzed by three iso-conversional methods.FTIR and 13C-NMR results suggested that the carbon structure of LPS coal was not altered greatly,while demineralization promoted the maturity of coal and the condensation degree of the aromatic ring,making the chemical structure of coal more stable.The oxygen-containing functional groups with low bond energy were reduced,and the ratio of aromatic carbon with high bond energy was increased,decreasing the pyrolysis reactivity.DTG curve-fitting results revealed that the thermal weight loss of LPS coal mainly came from the cleavage of aliphatic covalent bonds.By pyrolysis kinetics analysis of LPS-R and LPS-D,the apparent activation energies were 76±4 to 463±5 kJ/mol and 84±2 to 758±12 kJ/mol,respectively,under different conversion rates.The reactivity of the demineralized coal was inhibited to some extent,as the apparent activation energy of pyrolysis for LPS-D increased by acid treatment. 展开更多
关键词 demineralization Chemical structure of coal Coal pyrolysis Pyrolysis kinetics Iso-conversional
下载PDF
Demineralization mechanism and influence of parameters on high ash Indian coal by chemical leaching of acid and alkali solution 被引量:2
2
作者 Sushanta K. Behera Sudipto Chakraborty B. C. Meikap 《International Journal of Coal Science & Technology》 EI 2018年第2期142-155,共14页
The current research was investigated the mechanism of coal demineralization and the effect of leaching parameters on high ash coal and study the characterization of pre and post-treated coal. The two high ash Indian ... The current research was investigated the mechanism of coal demineralization and the effect of leaching parameters on high ash coal and study the characterization of pre and post-treated coal. The two high ash Indian coal selected from Mahanadi Coalfield Limited, Odisha, pulverized to 375, 230 and 180 gm particle size were undergone simultaneous acid and alkali treatment at a different concentration, temperature and time. The percent demineralization was increased with decrease the size of the particle and rises with leaching parameters. The investigation suggested 180 μm particle size offers efficient demineralization for both coals at 30% NaOH and 30% H2SO4 concentration. The alkali leaching leads to obtaining the demineralization 46% and 42% whereas acid treatment resulted in 34% and 32% of the original coal samples. The extent of demineralization was improved the calorific value of coal. Besides, the degree of demineralization was proved from the FTIR, XRF and FESEM-EDX analysis results. FTIR analysis result showed that the peak intensity of mineral band decreased by the leaching effect and the degree of demineralization was significantly obtained to large extent by the X-ray Fluorescence spectrometer; which elucidates major minerals removed from coal by the leaching effect of acid and alkali solution. 展开更多
关键词 High ash coal LEACHING Mineral matter demineralization Calorific value
下载PDF
Clinical assessment of demineralization and remineralization surrounding orthodontic brackets with FluoreCam
3
作者 Bora Korkut Duygu Korkut +1 位作者 Funda Yanikoglu Dilek Tagtekin 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2017年第4期373-377,共5页
Objective: To determine quantitatively the amount of demineralization and the ability of commercially available products and an experimental cream to inhibit or reverse orthodontic related demineralization.Methods: A ... Objective: To determine quantitatively the amount of demineralization and the ability of commercially available products and an experimental cream to inhibit or reverse orthodontic related demineralization.Methods: A total of 20 patients who were 25–35 years old and having orthodontic treatment for 6–8 months were chosen.Caries risk assessments were done for each patient and ones with "moderate risk" were included.Patients with fixed orthodontic appliances were divided into 4 groups(5 patients each) including one control and 3 study groups.All patients used same toothpaste 2 times a day during the 3 weeks study period.Additional to the toothpaste first study group used MI Paste Plus(GC, Tokyo, Japan), second study group used Remin Pro(Voco, Cuxhaven, Germany) and third group used an experimental remineralizing cream per day for 3 weeks.Maxillary central and lateral incisors of each patient were examined by FluoreCam(Daraza Therametric Technologies, USA) device.The examinations were performed at baseline and at the end of 1st, 2nd and 3rd weeks.Results: According to the FluoreCam measurements the control group showed significant amount of demineralization at the end of 3 weeks, moreover the amount of demineralization has gradually increased in time.At the end of the study all 3 study groups showed significant amount of remineralization and the amount of remineralization for all the 3 study groups has gradually increased in time.However the amount of remineralization for 3rd study group was lesser than the 1st and 2nd study groups.The remineralization amounts for the 1st and 2 nd study groups were determined to be identical.Conclusions: This study demonstrated that demineralization is measurable around orthodontic brackets and the demineralization can be completely inhibited and/or reversed by the use of commercially available remineralization products. 展开更多
关键词 demineralization REMINERALIZATION FluoreCam Orthodontic brackets MI Paste Plus Remin Pro
下载PDF
Demineralization of Gondwana coal with Pseudomonas mendocina strain B6-1: a case study of coal from Gopinathpur top and bottom seams of Mugma mine, Dhanbad, Jharkhand (India)
4
作者 Prakash K. Singh Asha Lata Singh +4 位作者 Mahendra P. Singh A. S. Naik Dharmshila Singh Spardha Rai Aniruddha Kumar 《International Journal of Coal Science & Technology》 EI 2016年第2期235-245,共11页
In the present investigation an attempt has been made to demineralize the Gondwana coal of Gopinathpur top and bottom seams of Mugma mine, Raniganj coalfield, Dhanbad with the help of Pseudomonas mendocina strain B6-1... In the present investigation an attempt has been made to demineralize the Gondwana coal of Gopinathpur top and bottom seams of Mugma mine, Raniganj coalfield, Dhanbad with the help of Pseudomonas mendocina strain B6-1. The change in the amount of ash yield and decrease in the concentration of selected minor elements like Na, K, Mn and Ca and environmentally sensitive selected trace elements such as Cd, Pb, Se, Ni, Mn, and Zn have been studied as a function of time of bacterial treatment as well as with variation in the bacterial biomass. After 28 days of bacterial treatment there was variable amount of decrease observed in ash yield as well as in the concentration of minor and trace elements. The removal of the elements was further enhanced with the increase in the bacterial biomass from 10 to 25 mg/mL. Due to over exploitation of superior grade coals in the country, the remaining coal resources, available for current use, are inferior in grade and contain high level of impurities and there is ample scope of bio-beneficiation of these coals using bacterial biomass. 展开更多
关键词 Pseudomonas mendocina Gondwana coal Minor and trace elements demineralization
下载PDF
Longitudinal evaluation of mineral loss at the earliest stage of enamel demineralization using micro-computed tomography
5
作者 Koji Watanabe Tomomi Nakamura +2 位作者 Takashi Ogihara Yoshiyuki Ochiai Shigeru Watanabe 《Health》 2012年第6期334-340,共7页
As the prevalence of dental caries decreases, the diagnosis and treatment of initial mineral loss resulting in white spot lesions have been getting more and more important. Since dental CT provides computed tomography... As the prevalence of dental caries decreases, the diagnosis and treatment of initial mineral loss resulting in white spot lesions have been getting more and more important. Since dental CT provides computed tomography images of a tooth with radiation exposure similar to panoramic radiography, it will become possible in the near future to evaluate the enamel mineral density using CT in the same way as measurement of the bone mineral density. Such computed tomography images enable dentists to perform longitudinal, three-dimensional, and precise evaluation of the enamel mineral density before a demineralized lesion becomes detectable by any other traditional means. Despite their advantage, there are not enough reports on evalu- ation of the enamel mineral density using CT. This study evaluated the serial changes in mineral density in the earliest stage of enamel demineralization. Eight bovine enamel specimens were coated with nail varnish. On each specimen, 4 square windows measuring 1 mm2 were created. The specimens were incubated in lactic acid solution at 38?C. During incubation, the windows were covered by nail varnish one by one at 30, 60, and 90 minutes, respectively. At 120 minutes, the specimens were removed from the solution. After the nail varnish was removed, X-ray microradiography was performed using SKYSCAN1172 at settings of 100 kV and 100 μA. The mean Hounsfield unit values (HUV) of enamel in a non-window area and those in the window areas were calculated every 180 μm over a depth of 0 - 900 μm and analyzed by two-way ANOVA. Data were affected by the incubation time and depth from the enamel surface, and there was not interaction between the two factors. Considering the incubation time, HUV of the whole measured enamel (0 - 900 μm) in the non-window group was significantly higher than that of the other incubated groups. Considering the depth, HUV was decreased at 721 - 900 μm compared with that at 0 - 180 μm in the 30-minute-incubated group, and the decrease spread to 361 - 900 μm in the 60- and 90- minutes-incubated groups. HUV was additionally calculated at increments of 18 μm and compared within the 60-minute-incubated group, and changes in the mineral density at the boundary of the earliest demineralized lesion could be observed. This study demonstrated detailed mineral density changes in the earliest period of demineralization. 展开更多
关键词 MINERAL Density MICRO-CT demineralization BOVINE ENAMEL Over Time Eval-uation
下载PDF
Influence of EDTA on Demineralization Rate of Dentine:Calcification Treatment in Root Canal Therapy 被引量:7
6
作者 Yang Ji Min He +2 位作者 Shijie Chang Xiaodong Zhang Huazhe Yang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2014年第7期692-698,共7页
The aim of this study was to investigate the influence of ethylenediaminetetraacetic acid (EDTA) irrigation on demineralization rate of dentine located in the apical third of root canal walls. Teeth were divided int... The aim of this study was to investigate the influence of ethylenediaminetetraacetic acid (EDTA) irrigation on demineralization rate of dentine located in the apical third of root canal walls. Teeth were divided into A and B two groups. In group A, all of the teeth was irrigated with EDTA and NaOCI (sodium hypochlorite), followed by cutting the apical third into slices longitudinally to examine the influence of EDTA on different portions of apical third of root canal. In group B, the apical third of a tooth was firstly cut into slices longitudinally, followed by coating the root canal walls with EDTA to in-situ observe the demineralization of dentine with different time. It was found that the influence of EDTA on root-canal was gradually increased from the apical to the upper end of the apical third for group A. In addition, the demineralization rate of dentine was remarkable in the first 25 min for group B. The diffusion of EDTA into root dentine would lead to potential damage to the dentine. Furthermore, demineralization rate curve was calculated. 展开更多
关键词 Ethylenediaminetetraacetic acid (EDTA) Root canal demineralization DENTINE
原文传递
A comparative study on demineralization of coals by acid-washing and solvent-extraction methods for low temperature catalytic coal gasification application 被引量:2
7
作者 Atul Sharma Akimitsu Matsumura 《Carbon Resources Conversion》 2019年第3期175-181,共7页
Catalytic coal gasification is an efficient way to achieve high conversion rates at low temperatures.Catalyst loss due to the reaction between the inherent mineral matter in the coal and the catalyst is a major hurdle... Catalytic coal gasification is an efficient way to achieve high conversion rates at low temperatures.Catalyst loss due to the reaction between the inherent mineral matter in the coal and the catalyst is a major hurdle for its practical application.The problem may be overcome by removing the mineral matter from the coal before use.Two demineralizing approaches,acid-washing and solvent-extraction methods are investigated for demineralizing the coals.Elemental analysis,XRD analysis,NMR analysis,and N_(2)adsorption analysis were made to compare the demineralization efficiency,crystallographic carbon microstructure,chemical structure,and micro-porosity,respectively.Solvent-extraction method was found be more efficient for demineralization.Difference was observed in the chemical structure and micro-porosity while crystallographic carbon-microstructure was found to be similar.Non-catalytic and catalytic gasification reactivity of the chars obtained by the two methods was compared.Gas composition and gas evolution profiles were also obtained and found to be influenced by the degree of demineralization. 展开更多
关键词 COAL demineralization Acid washing Solvent extraction Catalytic gasification
原文传递
Demineralized Bone Matrix Fibers plus Allograft Bone for Multilevel Posterolateral Spine Fusion: A Game Changer?
8
作者 Bodin Arnaud Barnouin Laurence +2 位作者 Coulomb Remy Haignere Vincent Kouyoumdjian Pascal 《Open Journal of Orthopedics》 2024年第2期105-113,共9页
Introduction: While autograft bone is the gold standard for multilevel posterolateral lumbar fusion, bone substitutes and graft extenders such as allograft bone, ceramics and demineralized bone matrix (DBM) have been ... Introduction: While autograft bone is the gold standard for multilevel posterolateral lumbar fusion, bone substitutes and graft extenders such as allograft bone, ceramics and demineralized bone matrix (DBM) have been used to avoid the morbidity and insufficient quantity associated with harvesting autologous bone. The primary objective of this retrospective study was to determine whether, in patients with increased risk of operative nonunion related to multilevel fusion, adding DBM fibers to mineralized bone allograft resulted in better fusion than using allograft alone. The secondary objectives were to evaluate how adding DBM fibers affects functional disability, low back pain, intraoperative blood loss and the nonunion rate. Methods: This retrospective study involved a chart review of consecutive patients who underwent multilevel lumbar spinal fusion and were operated on by a single surgeon. The patients were divided into two groups: 14 patients received mineralized bone allograft (control group) and 14 patients received a combination of mineralized bone allograft and DBM (experimental group). Patients were reviewed at a mean of 16.4 ± 2.2 months after surgery at which point CT scans were analyzed to determine whether fusion had occurred;Oswestry disability index (ODI) and pain were also evaluated. Results: A mean of 5 levels [min 2, max 13] were fused in these patients. Posterolateral fusion as defined by the Lenke classification was not significantly different between groups. The experimental DBM group had a significantly better composite fusion score than the control group (P Discussion: Adding DBM fibers to allograft bone during multilevel posterolateral spinal fusion was safe and produced better composite fusion than using allograft only as an autograft extender. 展开更多
关键词 Spine Surgery Demineralized Bone Fibers Bone Substitutes Retrospective Study
下载PDF
Biofilm three-dimensional architecture influences in situ pH distribution pattern on the human enamel surface 被引量:4
9
作者 Jin Xiao Anderson T Hara +3 位作者 Dongyeop Kim Domenick T Zero Hyun Koo Geelsu Hwang 《International Journal of Oral Science》 SCIE CAS CSCD 2017年第2期74-79,共6页
To investigate how the biofilm three-dimensional(3D) architecture influences in situ pH distribution patterns on the enamel surface. Biofilms were formed on human tooth enamel in the presence of 1% sucrose or 0.5% glu... To investigate how the biofilm three-dimensional(3D) architecture influences in situ pH distribution patterns on the enamel surface. Biofilms were formed on human tooth enamel in the presence of 1% sucrose or 0.5% glucose plus 0.5% fructose. At specific time points, biofilms were exposed to a neutral pH buffer to mimic the buffering of saliva and subsequently pulsed with 1% glucose to induce re-acidification. Simultaneous 3D pH mapping and architecture of intact biofilms was performed using two-photon confocal microscopy. The enamel surface and mineral content characteristics were examined successively via optical profilometry and microradiography analyses. Sucrose-mediated biofilm formation created spatial heterogeneities manifested by complex networks of bacterial clusters(microcolonies). Acidic regions(pH<5.5) were found only in the interior of microcolonies,which impedes rapid neutralization(taking more than 120 min for neutralization). Glucose exposure rapidly re-created the acidic niches, indicating formation of diffusion barriers associated with microcolonies structure. Enamel demineralization(white spots),rougher surface, deeper lesion and more mineral loss appeared to be associated with the localization of these bacterial clusters at the biofilm-enamel interface. Similar 3D architecture was observed in plaque-biofilms formed in vivo in the presence of sucrose. The formation of complex 3D architectures creates spatially heterogeneous acidic microenvironments in close proximity of enamel surface, which might correlate with the localized pattern of the onset of carious lesions(white spot like) on teeth. 展开更多
关键词 biofilms demineralization dental caries EXOPOLYSACCHARIDES microcolonies pH microenvironments PLAQUE Streptococcus mutans
下载PDF
Effect of Galla chinensis on the In Vitro Remineralization of Advanced Enamel Lesions 被引量:4
10
作者 Jacob M.ten Cate 《International Journal of Oral Science》 SCIE CAS CSCD 2010年第1期15-20,共6页
Aim The effect of Galla chinensis on de-/re-mineralization of advanced enamel lesions was investigated by using micro-CT in a prolonged in vitro experiment. Methodology Baseline mineral contents of sound enamels were ... Aim The effect of Galla chinensis on de-/re-mineralization of advanced enamel lesions was investigated by using micro-CT in a prolonged in vitro experiment. Methodology Baseline mineral contents of sound enamels were first analyzed. Then lesions were produced in an acidic buffer solution (2.2 mmol.L-1 Ca(NO3)2, 2.2 mmol-L1 KH2PO4, and pH=4.5) for 21 days, with thrice daily three-minute treatments, divided into four groups: Group A, 4 000 ppm crude aqueous extract of Galla chinensis (GCE); Group B, 4 000 ppm gallic acid; Group C, 1 000 ppm F aq. (as NaF, positive control); Group D, deionized water (negative control). Next, the blocks were immersed in a remineralization solution (1.5 mmol.Lz CaC12, 0.9 mmol.L1 KH2PO4, 0.1 ppm F, and pH=7,0) for 200 days. Mineral loss (ML) in each region of interest (ROI) and integrated mineral loss (IML) of the lesions were calculated (comparing with baseline mineral content of sound enamel) at different time points. Results After 21 days demineralization, fluoride treatment showed a statistically significant demineralization-inhibiting effect among the four groups, and after 200 days of remineralization, mineral content recovery was ordered (lowest to highest) as A=C〈B〈D. Conclusion GCE could slow down the remineralization of enamel in the surface layer and thereby facilitate ion transport into the lesion body. The mechanism of Galla chinensis in enhancing the remineralization of dental caries is different from fluoride. 展开更多
关键词 demineralization REMINERALIZATION advanced enamel lesion Galla chinensis
下载PDF
Reactivities of Shenfu Chars Toward Gasification with Carbon Dioxide 被引量:3
11
作者 ZHANG Jia-wei ZONG Zhi-min +7 位作者 WANG Tao-xia XIE Rui-lun DING Ming-jie CAI Ke-ying HUANG Yao-guo GAO Jin-sheng WU You-qing WEI Xian-yong 《Journal of China University of Mining and Technology》 EI 2007年第2期197-200,共4页
Five Shenfu char samples were prepared from Shenfu raw coal at different temperatures (950, 1100, 1200, 1300 and 1400℃) using a muffle furnace. Demineralization of the char samples was performed by treating them wi... Five Shenfu char samples were prepared from Shenfu raw coal at different temperatures (950, 1100, 1200, 1300 and 1400℃) using a muffle furnace. Demineralization of the char samples was performed by treating them with 10% nitric acid for 10 min in a CEM Discover microwave reactor. The gasification of the chars, and corresponding demineralized chars, in a carbon dioxide (CO2) atmosphere was conducted in a Netzsch STA 409Cl31F tempera- ture-programmed thermogravimetry apparatus. The effects of charring temperature and demineralization on the gasification reactivity of chars were systematically investigated. The results show that a char formed at a lower temperature is more reactive except for demineralized char formed at 1100℃, which is less reactive than char formed at 1200℃. Demineralization decreases the char reactivities toward gasification with CO2 to a small extent. 展开更多
关键词 demineralization temperature-programmed thermogravimetry reactivity
下载PDF
Effect of ash removal on structure and pyrolysis/gasification reactivity of a Chinese bituminous coal
12
作者 Qing He Yan Gong +2 位作者 Lu Ding Xingjun Wang Guangsuo Yu 《International Journal of Coal Science & Technology》 EI 2020年第3期444-455,共12页
In this study,the effect of ash removal on Shenfu bituminous coal was investigated.The coal was pretreated by hydrofluoric acid(HF)pickling,and the raw/pretreated coal chars were prepared at 900°C in a fixed bed ... In this study,the effect of ash removal on Shenfu bituminous coal was investigated.The coal was pretreated by hydrofluoric acid(HF)pickling,and the raw/pretreated coal chars were prepared at 900°C in a fixed bed reactor.The structure of coal and char were detected by Fourier transform infrared(FTIR)and Raman spectroscopy.The reactivity was tested in a thermogravimetric analyzer,including coal pyrolysis and char gasification.The reaction kinetics was analyzed through the Coats–Redfern method,master plots,the model-free and model-fitting method.The results show that the HF pickling can remove silicon from coal efficiently,and the macromolecular framework of coal is quite stable according to FTIR.The Raman parameters imply some carbonaceous structure on coal surface changed.For slow pyrolysis of coal,the effect of heating rate is considered.The changes of pyrolysis characteristics and kinetics are insignificant.For char gasification,the reactivity under isothermal and non-isothermal condition are discussed with an emphasis in different residence time of devolatilization process.In kinetic control region(low temperature),the activation energy(Ea)is very close(about 240 kJ/mol)for all chars.With the temperature increases,the reactivity of raw coal char is more easily suffered by diffusion.The random pore model is more suitable for the ash-free coal char,and the char with long residence time has a larger value of structural parameterψand smaller value of pre-exponential factor A.The Ea calculated by model-fitting and model-free method were in good agreement. 展开更多
关键词 GASIFICATION PYROLYSIS demineralization KINETICS Structure evolution Master plot
下载PDF
Clinical Management and Evaluation of White Spot Lesions: A Report of 11 Cases
13
作者 Domenico Aiello Riccardo Pulcini +2 位作者 Sandro Sestito Michele Mario Figliuzzi Sergio Paduano 《Open Journal of Stomatology》 2020年第7期156-173,共18页
<b><span>Introduction:</span></b><b><span> </span></b><span>Today’s society is always more interested to the concept of aesthetics. The patients frequently ask to... <b><span>Introduction:</span></b><b><span> </span></b><span>Today’s society is always more interested to the concept of aesthetics. The patients frequently ask to dentist to resolve unaesthetic problems of teeth, in particular that of the upper frontal group.</span><span> </span><span>The WSLs are enamel white </span><span>alterations due to alteration during the demineralization and remineralization of enamel. This effect is caused by alteration of the pH in the oral cavity and buffer action of saliva. An alteration of this relationship leads to a progressive </span><span>demineralization of enamel until the formation of a dental cavitation.</span><span> </span><b><span>Materials </span></b><b><span>and Methods:</span></b><span> </span><span>For this study are selected 11 patients, of which 3 men and 8 women, with total </span><span>of </span><span>17 WSLs. The inclusion criteria included WLSs with </span><span>ICDAS = 2 and WLSs caused by hypomineralization of traumatic origin. Th</span><span>es</span><span>e </span><span>patients were subjected to treatment with infiltrating resin according to operative procedure.</span><span> </span><b><span>Discussion:</span></b><span> </span><span>The therapy with infiltrating resin gave grea</span><span>t re</span><span>sults in 12 lesions out of 17. In the lesions where there weren’t a complete remiss</span><span>ion we obtained a great aesthetic improvement and a good reduction of </span><span>lesions. The follow up could improve the result after a better rehydration of </span><span>hard tissue.</span><span> </span><b><span>Conclusions:</span></b><span> </span><span>With a correct selection of cases and good operativ</span><span>e procedure, the use of the micro-infiltrative technique by low viscosity resin is </span><span>a good procedure to resolve WSLs problems of non-orthodontic origins. Oth</span><span>er studies with a larger sample are required to validate this clinical approach.</span> 展开更多
关键词 WSL Microinfiltration demineralization ICON ENAMEL
下载PDF
Use of demineralized bone matrix in the extremities 被引量:4
14
作者 Georgios I Drosos Panagiotis Touzopoulos +2 位作者 Athanasios Ververidis Konstantinos Tilkeridis Konstantinos Kazakos 《World Journal of Orthopedics》 2015年第2期269-277,共9页
Autologous bone graft is considered as the gold standard for all indications for bone grafting procedures but the limited availability and complications in donor site resulted in seeking other options like allografts ... Autologous bone graft is considered as the gold standard for all indications for bone grafting procedures but the limited availability and complications in donor site resulted in seeking other options like allografts andbone graft substitutes. Demineralized bone matrix(DBM) is an allograft product with no quantity limitation. It is an osteoconductive material with osteoinductive capabilities, which vary among different products, depending on donor characteristics and differences in processing of the bone. The purpose of the present review is to provide a critical review of the existing literature concerning the use of DBM products in various procedures in the extremities. Clinical studies describing the use of DBM alone or in combination with other grafting material are available for only a few commercial products. The Level of Evidence of these studies and the resulting Grades of Recommendation are very low. In conclusion, further clinical studies of higher quality are required in order to improve the Recommendation Grades for or against the use of DBM products in bone grafting procedures. 展开更多
关键词 BONE GRAFTING ALLOGRAFT Demineralized BONE MATRIX NON-UNION
下载PDF
Use of demineralized bone matrix in spinal fusion 被引量:4
15
作者 Konstantinos Tilkeridis Panagiotis Touzopoulos +3 位作者 Athanasios Ververidis Sotirios Christodoulou Konstantinos Kazakos Georgios I Drosos 《World Journal of Orthopedics》 2014年第1期30-37,共8页
Spinal fusion remains the gold-standard treatment for several pathological spine conditions. Although, autologous Iliac Crest Bone Grafting is considered the goldstandard graft choice to promote spinal fusion; however... Spinal fusion remains the gold-standard treatment for several pathological spine conditions. Although, autologous Iliac Crest Bone Grafting is considered the goldstandard graft choice to promote spinal fusion; however, it is associated with significant donor site morbidity and a limited graft quantity. Therefore, several bone graft alternatives have been developed, to augment arthrodesis. The purpose of this review is to present the results of clinical studies concerning the use of demineralized bone matrix(DBM), alone or as a composite graft, in the spinal fusion. A critical review of the English-language literature was conducted on Pubmed, using key word "demineralized bone matrix", "DBM", "spinal fusion", and "scoliosis". Results had been restricted to clinical studies. The majority of clinical trials demonstrate satisfactory fusion rates when DBM is employed as a graft extender or a graft enhancer.Limited number of prospective randomized controlled trials(4 studies), have been performed comparing DBM to autologous iliac crest bone graft in spine fusion. The majority of the clinical trials demonstrate comparable efficacy of DBM when it used as a graft extender in combination with autograft, but there is no clinical evidence to support its use as a standalone graft material. Additionally, high level of evidence studies are required, in order to optimize and clarify the indications of its use and the appropriate patient population that will benefit from DBM in spine arthrodesis. 展开更多
关键词 BONE GRAFTS Demineralized BONE MATRIX SPINAL FUSION SCOLIOSIS
下载PDF
Effects of hypoxia on the biological behavior of MSCs seeded in demineralized bone scaffolds with different stiffness 被引量:1
16
作者 Yuanyuan Sun Guobao Chen Yonggang Lv 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2019年第2期309-320,共12页
Matrix stiffness has been demonstrated in many studies to adjust the biological behaviors of mesenchymal stem cells (MSCs). However, in the initial phase of bone restore, MSCs will encounter a hypoxic microenvironment... Matrix stiffness has been demonstrated in many studies to adjust the biological behaviors of mesenchymal stem cells (MSCs). However, in the initial phase of bone restore, MSCs will encounter a hypoxic microenvironment. Studying the connection existing between the matrix stiffness and biological behavior of MSCs under hypoxic condition can better simulate the microenvironment at the prime period of bone repairment. In this work, three-dimensional (3D) decalcified bone scaffolds with diverse stiffness (high stiffness (66.06 ± 27.83) MPa, medium stiffness (26.90 ± 13.16) MPa, and low stiffness (0.67 ± 0.14) MPa) but same microstructure have been prepared by controlling decalcification time. In addition, the decellularized bone scaffold was regard as control group and its stiffness was (230.93 ± 72.65) MPa. The viability, proliferation, infiltration, and osteogenic differentiation of MSCs seeded into these 3D demineralized bone scaffolds were systematically investigated under 100 μM CoCl2-simulated hypoxic and normoxic environments. The results showed that the viability, proliferation, and extracellular matrix (ECM) secretion of MSCs had no significant difference on scaffolds with diverse stiffness but the degree of collagen deposition of MSCs gradually increased with the increase of scaffold stiffness both under normoxia and hypoxia. Compared to normoxia, the viability, proliferation, ECM secretion, vascular endothelial growth factor (VEGF) expression, and osteogenis of MSCs on the scaffolds with the same stiffness were evidently inhibited by hypoxia. Additionally, under hypoxic condition, the expression of VEGF and hypoxia inducible factor 1α(HIF-1α) in MSCs on the low stiffness scaffold was markedly increased comparing to those on other groups. In summary, we found that the low stiffness scaffold can improved the proliferation and osteoginic differentiation of MSCs under hypoxic environment, which may help to explore efficient methods for bone defect repairing. 展开更多
关键词 MESENCHYMAL stem cells HYPOXIA Matrix STIFFNESS Demineralized bone SCAFFOLD OSTEOGENIC differentiation
下载PDF
Permeable Resin Applied to Surface of Sealed Demineralized Enamel
17
作者 裴秀洁 白玉兴 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2011年第2期251-253,共3页
The self-made demineralized teeth samples treated with preamble resin to seal or not were observed under electron microscopy and tested microhardness value to show surface structure and hardness of demineralized ename... The self-made demineralized teeth samples treated with preamble resin to seal or not were observed under electron microscopy and tested microhardness value to show surface structure and hardness of demineralized enamel.The experimental results showed that the permeable resin formed longer resin tags on the surface of the enamel and a lot of cracks in the deep part which has a higher microhardness value than ordinary enamel. 展开更多
关键词 permeable resin demineralized enamel resin tag
下载PDF
Advantage of Introducing Quantitative Light-Induced Fluorescence in School Dental Checkups
18
作者 Koji Watanabe Takashi Sasabe +7 位作者 Akihiro Nakamura Kosuke Eda Kosuke Tanase Hidefumi Ikeda Naoko Ohata Yukiko Minohara Kenshi Maki Shigeru Watanabe 《Health》 2018年第8期1095-1106,共12页
Background: Caries detection in school oral examinations insufficient accuracy. Objective: To evaluate advantages of introducing quantitative light-induced fluorescence-digital (QLF-D) in school oral examinations. Met... Background: Caries detection in school oral examinations insufficient accuracy. Objective: To evaluate advantages of introducing quantitative light-induced fluorescence-digital (QLF-D) in school oral examinations. Methods: Experiment No. 1. Early demineralized lesions in the upper and lower incisors and canines were visually inspected by three dentists and by QLF-D. The numbers of tooth planes with early demineralized lesions were compared between the methods. Experiment No. 2. Approximal demineralized lesions in molars were assessed by visual inspection, x-ray imaging, and QLF-D. The numbers of tooth planes with demineralized lesions were compared among the methods. Experiment No. 3. Plaque distribution was evaluated by QLF-D and a traditional staining method. The ratio of the diameter of plaque to tooth crown in the tooth axis direction in each method was calculated. The results were evaluated by Pearson’s correlation coefficient analysis and Bland-Altman plot. Results: Experiment No. 1. The three dentists found 0.67 tooth planes on average. QLF-D found 22 tooth planes with early demineralized lesions in the same samples. Experiment No. 2. Fourteen approximal tooth planes of molars were found to have demineralized lesions by x-ray imaging. QLF-D detected 71.4% of the tooth planes out of the 14, whereas visual inspection found 7.1%. Experiment No. 3. The Pearson’s correlation coefficient for the evaluations of plaque distribution between the QLF-D and traditional staining methods was 0.77 (P Conclusion: The results support introduction of QLF-D for use in school dental examinations. 展开更多
关键词 Oral CHECKUP Early Demineralized LESION Approximal Demineralized LESION QUANTITATIVE LIGHT-INDUCED Fluorescence-Digital
下载PDF
Soft tissue swelling incidence using demineralized bone matrix in the outpatient setting
19
作者 Kingsley R Chin Fabio JR Pencle +1 位作者 Jason A Seale Juan M Valdivia 《World Journal of Orthopedics》 2017年第10期770-776,共7页
AIM To assess use of demineralized bone matrix(DBM) use in anterior cervical discectomy and fusion(ACDF) in outpatient setting.METHODS One hundred and forty-five patients with prospectively collected data undergoing s... AIM To assess use of demineralized bone matrix(DBM) use in anterior cervical discectomy and fusion(ACDF) in outpatient setting.METHODS One hundred and forty-five patients with prospectively collected data undergoing single and two level ACDF with DBM packed within and anterior to polyetheretherketone(PEEK) cages. Two groups created, Group 1(75) outpatients and control Group 2(70) hospital patients. Prevertebral soft tissue swelling(PVSTS) was measured anterior to C2 and C6 on plain lateral cervical radiographs preoperatively and one week postoperatively and fusion assessed at two years. RESULTS There was no intergroup significance between preoperative and postoperative visual analogue scales(VAS)and neck disability index(NDI) scores between Group 1 and 2. Mean preoperative PVSTS in Group 1 was 4.7 ± 0.2 mm at C2 level and 11.1 ± 0.5 at C6 level compared to Group 2 mean PVSTS of 4.5 ± 0.5 mm and 12.8 ± 0.5, P = 0.172 and 0.127 respectively. There was no radiographic or clinical evidence of adverse reaction noted. In Group 1 mean postoperative PVSTS was 5.5 ± 0.4 mm at C2 and 14.9 ± 0.6 mm at C6 compared Group 2 mean PVSTS was 4.9 ± 0.3 mm at C2 and 14.8 ± 0.5 mm at C6, P = 0.212 and 0.946 respectively. No significant increase in prevertebral soft tissue space at C2 and C6 level demonstrated.CONCLUSION ACDF with adjunct DBM packed PEEK cages showed a statistical significant intragroup improvement in VAS neck pain scores and NDI scores(P = 0.001). There were no reported serious patient complications; post-operative radiographs demonstrated no significant difference in prevertebral space. We conclude that ACDF with DBMpacked PEEK cages can be safely done in an ASC with satisfactory outcomes. 展开更多
关键词 AMBULATORY SURGERY center ANTERIOR cervical DISCECTOMY and fusion Demineralized bone matrix Less Exposure SURGERY Packed POLYETHERETHERKETONE CAGES
下载PDF
Quality Testing of Air Conditioner Condensate and Its Potential in Water Conservation
20
作者 Apurva Sabnis Madhuvanti Kale +1 位作者 Manik Dhanorkar Sharad P. Kale 《Journal of Water Resource and Protection》 2020年第2期93-101,共9页
A major part of world is facing water shortages today. While the world’s population has grown to more than 7.75 billion, the quantity of sweet water has remained the same. The ever increasing use of water by such a l... A major part of world is facing water shortages today. While the world’s population has grown to more than 7.75 billion, the quantity of sweet water has remained the same. The ever increasing use of water by such a large population has resulted in pollution of many water sources. The developing world where a large fraction of total world population is located faces water scarcity in a more severe manner than the developed world. The developed world has managed to control human population and preserve natural water resources more effectively. As a result of this and also due to stabilized population, they face lesser problems for water availability. Indian population stands at 1.386 billion as nowadays. The erratic monsoon rains over last few years have resulted in floods and subsequent water shortages in summer months in major part of the country. A similar situation is faced by many Asian and African countries. The means of recycling and using every possible source of water are always welcome in these countries. Since many of these countries lie in tropical or semitropical zone, the average relative humidity is more than 50% for most of the year. Changing life styles in these countries and spread of information technology based sectors have resulted in a growth spurt in air conditioning facilities. An air conditioner draws heat from surrounding air and cools the premises to desired temperature. During this process, a large amount of moisture in the atmosphere gets condensed and is drained out. There are no efforts made to recover this water in India and neighbouring countries. We have undertaken studies to check the quality of this water and see the feasibility of its use in a decentralized but effective manner. The results show that this water condensate from air conditioners is highly pure, substantial and available almost round the year. This can help in recovering millions of litres of good quality water daily. This water would find uses in industries, laboratories, households and farming. It would also create good business opportunities. 展开更多
关键词 WATER Conservation Resource Sustainability Air CONDITIONER CONDENSATE Relative Humidity Distilled WATER Demineralized WATER Total Dissolved SOLIDS (TDS) HARD WATER
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部