Venous segmentation of the spleen

Summary The authors conducted a study of the human splenic venous system by corrosion cast. The existence of two main venous territories or lobes separated by an avascular plane is confirmed. Smaller territories or segments, drained systematically by segmentary veins, and also separated by avascular planes, are defined in them. Their number ranged from four to eight, the mean being five segments. Four different ways of confluence of intrasplenic vessels forming the splenic vein are described.

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Segmentation veineuse de la rate

Résumé Les auteurs ont mené une étude du système veineux de la rate chez l'homme par injection-corrosion. Ils confirment l'existence de deux principaux territories ou lobes séparés par un plan avasculaire ; des territories plus petits, ou segments, drainés de manière systématique par des veines segmentaires, et également séparés par des plans avasculaires sont définis à l'intérieur de ces lobes. Leur nombre se situe entre quatre et huit, la moyenne est de cinq segments. Quatre modes différents de confluence des vaisseaux intra-spléniques à l'origine de la v. splénique sont décrits.

     

Surface structure and properties of biomedical NiTi shape memory alloy after Fenton's oxidation

Fenton's oxidation is traditionally used to remove inorganic and organic pollutants from water in waster water treatment. It is an advanced oxidation process in which H2O2 is catalytically decomposed by ferrous irons into hydroxyl radicals (*OH) which have a higher oxidation potential (2.8V) than H2O2. In the work reported here, we for the first time use Fenton's oxidation to modify the surface of biomedical NiTi shape memory alloy (SMA). The influences of Fenton's oxidation on the surface microstructure, blood compatibility, leaching of harmful Ni ions and corrosion resistance in simulated body fluids is assessed using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, inductively coupled plasma mass spectrometry, electrochemical tests, hemolysis analysis and the blood platelet adhesion test. The mechanical stability of the surface titania film produced by Fenton's oxidation as well as their effects on the shape memory behavior of the SMA are studied by bending tests. Our results show that Fenton's oxidation produces a novel nanostructured titania gel film with a graded structure on the NiTi substrate without an intermediate Ni-rich layer that is typical of high-temperature oxidation. Moreover, there is a clear Ni-free zone near the top surface of the titania film. The surface structural changes introduced by Fenton's oxidation improve the electrochemical corrosion resistance and mitigate Ni release. The latter effects are comparable to those observed after oxygen plasma immersion ion implantation reported previously and better than those of high-temperature oxidation. Aging in boiling water improves the crystallinity of the titania film and further reduces Ni leaching. Blood platelet adhesion is remarkably reduced after Fenton's oxidation, suggesting that the treated SMA has improved thrombo resistance. Enhancement of blood compatibility is believed to stem from the improved hemolysis resistance, the surface wettability and the intrinsic electrical characteristics of the titania film. The titania film produced by Fenton's oxidation has good mechanical stability and does not adversely impact the shape memory behavior of NiTi. Our work suggests that Fenton's oxidation is a promising low-temperature, low-cost surface modification method for improving the surface properties of biomedical NiTi SMA.     

3种牙科铸造金属模拟唾液浸泡后粗糙度的变化

目的：通过考察钴铬合金、镍铬合金以及纯钛在不同pH值人工唾液中浸泡后表面粗糙度的变化,研究3种常用牙科金属的耐腐蚀能力。方法：将3种金属的标准铸造试件逐级打磨抛光后。浸泡于pH值分别为7．0和5．6的人工唾液中。3个月后检测试件表面粗糙度,并用金相显微镜观察试件表面。采用SPSS11．0软件包对数据进行单因素方差分析及t检验。结果：pH=5．6的人工唾液浸泡后,3种材料表面粗糙度有显著差异,镍铬合金〉钴铬合金〉纯钛金属（P〈0．01）。pH=7．0的人工唾液浸泡后,镍铬合金表面粗糙度大于钴铬合金和纯钛（P〈0．01）,但钴铬合金和纯钛之间无统计学差异（p〉0．05）。pH=5．6人工唾液浸泡组的镍铬合金和钴铬合金表面粗糙度大于pH=7．0组的同种材料（P〈0．01）。各试验组表面粗糙度大小与显微镜观察到的材料表面腐蚀程度一致。结论：纯钛在酸性和中性环境下均有较强的耐腐蚀性,钴铬合金、镍铬合金在酸性介质中的耐腐蚀性较差。3种金属的耐腐蚀性由大到小排列为：纯钛金属〉钴铬合金〉镍铬合金。     

钴铬、镍铬、含钛镍铬烤瓷合金在人工唾液中耐腐蚀性能的比较

目的:评价钴铬、镍铬、含钛镍铬烤瓷合金在人工唾液中的耐腐蚀性能。方法:采用动电位极化曲线法测定钴铬、镍铬、含钛镍铬烤瓷合金试件的自腐蚀电流密度、极化电阻、自腐蚀电位,并得出3种合金的极化曲线。应用场发射扫描电子显微镜(FSEM),观察实验前、后试件表面的形貌变化。采用SPSS11.0软件包对数据进行单因素方差分析。结果:钴铬合金试件自腐蚀电流密度显著低于镍铬合金(P<0.05)及含钛镍铬合金(P<0.05);含钛镍铬合金试件自腐蚀电流密度低于镍铬合金(P<0.05)。钴铬合金试件的极化电阻显著高于镍铬合金(P<0.05)及含钛镍铬合金(P<0.05);含钛镍铬合金试件的极化电阻明显高于镍铬合金(P<0.05)。钴铬合金试件的自腐蚀电位高于镍铬合金(P<0.05)及含钛镍铬合金(P>0.05);含钛镍铬合金试件的自腐蚀电位高于镍铬合金(P>0.05)。FSEM显示,钴铬合金试样表面腐蚀较镍铬合金及含钛镍铬合金轻微。结论:钴铬烤瓷合金的耐腐蚀性优于镍铬烤瓷合金及含钛镍铬烤瓷合金,含钛镍铬烤瓷合金耐腐蚀性不及镍铬烤瓷合金。     

Influence of different polyphenol extracts of Taxus baccata on the corrosion process and their effect as additives in electrodeposition

The corrosion inhibition of carbon steel in 1 M HCl solution by methylene dichloride (MDE), ethyl acetate (EAE) and butanolic (BE) extracts of Taxus baccata and the evaluation of their behaviours as additives in electroplating were studied. Potentiodynamics polarization, electrochemical impedance spectroscopy (EIS), weight loss meseurment and scanning electron microscopy (SEM) methodes were employed for this investigation. The experimental results indicate that all tested extracts exhibited a good corrosion inhibition reaching values of 79%, 82% and 74% for MDE, EAE and BE respectively. However, the protection efficiency decreased whil temperature goes up. The polarization curves showed that MDE, EAE and BE acted as mixed type inhibitors. The free adsorption energies of the extracts vary from (?23 KJ/mol) to (?19 KJ/mol) revealed a spontaneous physical adsorbtion on the steel surface following Langmuir isotherm. The electrodeposition of zinc on the steel in chloride solution using different concentrations of Taxus baccata extracts as additives was performed using a DC-supply. The presence of the extracts as additives in the electrolytical bath performes the quality of the electrodeposition of the zinc. These constatation was observed throught the deposit parameters as the brightness, the adhesion and the thickness. It was found that the electrodeposition process changed in both additive concentration and extract type. In addition their efficiency against corrosion was evaluated indicating that the samples coated in the presence of extracts were more resistant.     

Variations in the Branching Pattern of Renal Artery and its Clinical Implications

Renal artery arises from the aorta and divides into an anterior and posterior division. The anterior division further divides into 4 segmental arteries: apical, superior anterior, middle anterior and lower. The posterior division continues as posterior segmental artery. These segmental arteries serve as end arteries and supply a specified segment of the kidney. In the present study, variations in the branching pattern of the renal artery and vascular segmentation of the kidney was studied by dissection, corrosion cast and radiographic methods in 72 kidneys obtained from post-mortem cases of Forensic department. Five vascular segments were observed in all the kidneys studied. The anterior division of the renal artery showed considerable variations in giving segmental branches on the basis of which it was classified into 6 types; most common being anterior division dividing into an upper and a lower branch. The upper branch further divided into an apical and an upper segmental artery and the lower branch divided into middle and a lower segmental artery (29.19%). Knowledge of branching pattern of the renal artery is very important for the proper interpretation of radiographic interpretation of renal vasculature and planning surgical procedures in cases of renal trauma, renal transplantation, and partial nephrectomy.     

Mucosal microvasculature of the gastric pars nonglandularis and margo plicatus in the horse: A scanning electron microscopic study on corrosion casts

The microvascularisation of the equine non-glandular gastric mucosa was investigated using corrosion casts for scanning electron microscopy. Specimens from 11 healthy horses were examined. Corresponding to the high incidence of gastric lesions in the margo plicatus, special attention was paid to the differentiation between the pars nonglandularis and the margo plicatus as a distinct area of the aglandular mucosa. In both areas, the blood vessels of the lamina propria mucosae were arranged in three vascular layers; i. e. I) a basal, II) an intermediate, and III) a subepithelial horizontal level. In the basal (I) and in the intermediate (II) layers the vascular supply was organised in arterial retia-rete arteriosum profundum, rete arteriosum subpapillare- and venous plexus-plexus venosus profundus, plexus venosus subpapillare. Vertical interconnections integrated the layers into the vascular network of the entire lamina propria. The subepithelial (III) layer represented the blood vessels of all the individual connective tissue papillae in the lamina propria mucosae. Ansae capillares intrapapillares were found in the pars nonglandularis. In contrast, each of the papilla of the margo plicatus contained a "cone shaped" rete capillare intrapapillare. The thicker epithelium and lamina propria mucosae of the margo plicatus was therefore supplied by less numerous, but longer intrapapillary blood vessel systems. The typical vascular components of the margo plicatus may be considered to be one of several links in the etiological chain which characterises gastric mucosal lesions in the horse's stomach.     

Corrosion in Haas expanders with and without use of an antimicrobial agent: an in situ study

Objectives

The purpose of this study was to evaluate in situ the occurrence of corrosion in the soldering point areas between the wire, silver brazing and band in Haas expanders.

Material and Methods

Thirty-four 7-12-year-old patients who needed maxillary expansion with a Haas expander were randomly assigned to two groups of 17 individuals each, according to the oral hygiene protocol adopted during the orthodontic treatment: Group I (control), toothbrushing with a fluoride dentifrice and Group II (experimental), toothbrushing with the same dentifrice plus 0.12% chlorhexidine gluconate (Periogard^®) mouthrinses twice a week. The appliances were removed after approximately 4 months. Fragments of the appliances containing a metallic band with a soldered wire were sectioned at random for examination by stereomicroscopy, scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS). Data were analyzed statistically by Fisher''s test at 5% significance level.

Results

The analysis by optical microscopy revealed areas with color change suggestive of corrosion in the soldering point areas joining the band and the wire in all specimens of both groups, with no statistically significant difference between the groups (p=1). The peaks of chemical elements (Ni, Fe, Cr, O, C and P) revealed by EDS were also similar in both groups.

Conclusion:

Color changes and peaks of chemical elements suggestive of corrosion were observed in the soldering point areas between the wire, silver brazing and band in both control and experimental groups, which indicate that the 0.12% chlorhexidine gluconate mouthrinses did not influence the occurrence of corrosion in situ.     

三种口腔铸造合金耐蚀性及表面氧化膜的比较

目的 探讨3种常用口腔铸造合金模拟烤瓷前后的耐蚀性差异及氧化膜成分,以期为临床合理选择非贵金属合金提供依据.方法 用电感耦合等离子体原子发射光谱法(inductively coupled plasma atomic emission spectroscopy,ICP-AES)检测模拟烤瓷前后3种常用烤瓷非贵金属合金(镍铬合金、钴铬合金、镍钛合金)在达尔伯克改良伊格尔培养液中浸泡30 d后离子析出的种类和含量.同时用X射线光电子能谱(X-ray photoelectron spectroscopy,XPS)对模拟烤瓷后合金表面生成的氧化膜进行分析,扫描电镜(SEM)对合金表面腐蚀形态进行观察.结果 模拟烤瓷前3种合金离子总质量浓度由大到小依次为镍铬合金[(2.829±0.694)mg/L]、钴铬合金[(2.120±0.418)mg/L]、镍钛合金[(1.211±0.101)mg/L];镍铬合金组镍的质量浓度[(1.531±0.392)mg/L]＞镍钛合金组[(0.830±0.052)mg/L],钴和钼离子质量浓度由大到小为钴铬合金组[钴:(0.048±0.011)mg/L;钼:(1.562±0.333)mg/L]、镍铬合金组[钴:(0.034±0.002)mg/L;钼:(1.264±0.302)mg/L]、镍钛合金组[钴:(0.013±0.006)mg/L;钼:(0.151±0.026)mg/L],差异有统计学意义(P＜0.05).模拟烤瓷后3种合金离子析出总量[镍铬合金:(0.861±0.054)mg/L;钴铬合金:(0.695±0.327)mg/L;镍钛合金:(0.892±0.115)mg/L]均比未模拟烤瓷处理的合金离子析出总量少,差异有统计学意义(P＜0.05).XPS分析显示,模拟烤瓷后3种合金表面Cr2O3和钼、镍氧化物的含量增加.结论 3种常用烤瓷铸造合金中镍铬合金的离子析出量最大,耐蚀性最差;烤瓷加热处理可促进这3种合金生成连续的Cr2O3氧化膜,使合金的耐蚀性增强.

Abstract：

Objective To evaluate the types and compositions of oxide films formed during porcelain-fused-to-metal( PFM ) firing on three kinds of dental casting alloys, and to investigate the corrosion property of these alloys in Dulbecco's modification of Eagle's medium( DMEM ) cell culture fluid, before and after PFM firing. Methods Specimens of three dental casting alloys( Ni-Cr, Co-Cr and Ni-Ti) before and after PFM firing were prepared, and were immersed in DMEM cell culture fluid. After 30 days, the type and concentration of released metal ions were measured using inductively coupled plasma atomic emission spectroscopy(ICP-AES). X-ray photoelectron spectroscopy(XPS) and scanning electron microscope( SEM )were used for analysis of oxide film on the alloys. One way-ANOVA was adopted in data analysis. Results The total amount of metal ions released from the three dental alloys was found to be highest in Ni-Cr alloy [(2.829±0.694) mg/L], followed by Co-Cr[(2. 120 ±0.418) mg/L]and Ni-Ti alloy[(1.211 ±0. 101 ) mg/L]. The amount of Ni ions released from Ni-Cr alloys[( 1. 531 ± 0. 392) mg/L]was higher than that from Ni-Ti alloys[(0. 830 ±0. 052) mg/L]. The amount of Cr, Mo ions released from Co-Cr alloy [Cr: (0. 048 ± 0. 011 ) mg/L, Mo: ( 1. 562 ± 0. 333 ) mg/L]was higher than that from Ni-Cr alloy[Cr:(0. 034 ±0. 002) mg/L, Mo: ( 1. 264 ±0. 302) mg/L]and Ni-Ti alloy[Cr: (0. 013 ±0. 006) mg/L, Mo:(0. 151 ±0. 026) mg/L](P ＜0. 05). After PFM firing, the total amount of metal irons released from the three dental alloys decreased[N i-Cr: (0. 861 ± 0. 054 ) mg/L, Co-Cr: (0. 695 ± 0. 327 ) mg/L, Ni-Ti:(0. 892 ±0. 115) mg/L](P ＜ 0. 05). In addition, XPS showed increase of Cr2O3 and Mo-Ni oxide on the surface of all the alloys after PFM firing. Conclusions The amount of ions released from Ni-Cr alloy was the highest among the three dental casting alloys, this means Ni-Cr alloy is prone to corrode. The PFM firing process changed the alloys' surface composition. Increased Ni, Cr and Mo were found in oxide film, and the increase in Cr2O3 can improve the corrosion-resistance of alloys.     

TiN、TiCN涂层对牙科纯钛耐腐蚀性能的影响

目的:在模拟口腔环境条件下,研究TiN、TiCN涂层对纯钛耐腐蚀性能的影响。方法:选用制作活动义齿常用的牙科纯钛材料,制作成10mm×l0mm×1mm规格的试件15个,随机分为A、B、C 3组。其中,B、C组采用电弧离子镀物理气相沉积技术,分别在其表面沉积一层厚为2.5μm的TiN、TiCN涂层。应用场发射环境扫描电子显微镜(FESEM)观察各组试样表面形貌并进行显微能谱分析;运用纳米压痕技术测试涂层的硬度和弹性模量;将3组试件分别置于人工唾液中,通过PARSTAT’2273电化学工作站进行极化曲线分析。采用SPSS 17.0软件包对数据进行t检验、单因素方差分析及非参数检验。结果:纳米压痕技术测试显示,B、C组的显微硬度及弹性模量均显著高于A组(P<0.001),而C组又显著高于B组(P<0.01)。电化学实验结果显示,3组试件的自腐蚀电位为A>B>C(P<0.05),自腐蚀电流为A0.05),三者的钝化膜击穿电位关系为A相似文献