Development of a carbon nanotubes paste electrode modified with crosslinked chitosan for cadmium(II) and mercury(II) determination

A functionalized carbon nanotubes paste electrode modified with cross-linked chitosan for the determination of trace amounts of cadmium(II) and mercury(II) by linear anodic stripping voltammetry is described. Under optimal experimental conditions, the peak current was linear in the Cd(II) concentration range from 5.9 × 10⁻⁸ to 1.5 × 10⁻⁶ mol L⁻¹ with a detection limit of 9.8 × 10⁻⁹ mol L⁻¹ and, for Hg(II) from 6.7 × 10⁻⁹ to 8.3 × 10⁻⁸ mol L⁻¹with a detection limit of 2.4 × 10⁻⁹ mol L⁻¹. The proposed method was successfully applied for the determination of Hg(II) in natural and industrial wastewater samples, and Cd(II) in sediments, human urine, natural, and industrial wastewater samples.     

Autocatalytic reduction of Cu(II) to copper by Co(II) studied by electrochemical quartz crystal microgravimetry in a wall jet cell

Electrochemical Quartz Crystal Microgravimetry (EQCM) studies were carried out in a new type of electroless copper plating solution containing Co(II)-ethylenediamine species as a reducing agent for Cu(II)-ethylenediamine complex. The rates of partial reactions of Cu(II) reduction and Co(II) oxidation were studied as a function of the electrode potential (?0.3 V to 0.05 V vs. SHE) under stopped-flow and wall jet conditions. The increase in the rate of partial reactions and the overall process under wall jet conditions suggests diffusion limitations occur in the transport of reacting species (Cu(II) and Co(II)) to the electrode and/or inhibiting products of reaction (Co(III) and ethylenediamine) to the bulk of the solution. Anodic dissolution of copper starts at 0.0 V.     

苯丙芘联合佛波酯恶性转化HIOEC细胞的实验研究

目的:诱导永生化口腔上皮细胞系HIOEC细胞恶性转化,建立HIOEC-B(a)P-TPA细胞系。方法:通过递增浓度的化学致癌剂苯丙芘复合促癌剂佛波酯体外诱导HIOEC细胞,筛选得到具有恶性表型的鳞状细胞癌细胞系HIOEC-B(a)P-TPA。通过微分干涉显微镜和HE染色观察细胞形态学改变,免疫组化染色检测细胞角蛋白和波形蛋白表达情况;软琼脂集落形成、裸小鼠异体皮下成瘤性鉴定HIOEC-B(a)P-TPA细胞的恶性表型。结果:(1)HIOEC细胞诱导培养6个月后,可以在正常生理钙离子浓度、含胎牛血清培养液中生长;(2)细胞在诱导过程中形态多变,最后以成纤维样细胞为主,异形性明显;(3)HIOEC-B(a)P-TPA细胞中细胞角蛋白表达减弱,同时表达波形蛋白;(4)有很强的软琼脂集落形成能力,集落形成率为24.5%;(5)HIOEC-B(a)P-TPA细胞尚未观察到成瘤性。结论:生物化学致癌因素B(a)P和TPA可诱导HIOEC细胞恶性转化,反映了口腔黏膜上皮细胞体外恶变发生、发展过程。     

The pzc of Au(111) and Pt(111) in a perchloric acid solution: an ex situ approach to the immersion technique

An electrochemically activated glassy carbon electrode was employed for fabrication of an H₂O₂ sensor through incorporation of horseradish peroxidase (HRP) into the activated surface layer of the electrode during the electrochemical deposition of phenol. The immobilized HRP showed excellent stability and biocatalytic activity for the reduction of H₂O₂. The enzyme electrode exhibited linear responses to H₂O₂ in a concentration range of 5 × 10^?8 to 1 × 10^?5 M and its response time was less than 5 s. At a moderate operating potential of 0V vs. SCE, the direct responses of H₂O₂ and other electroactive interferants, such as ascorbate and urate, on the activated glassy carbon electrode were minimal. The interference of ascorbate and urate was further reduced by the insulating polyphenol film.     

Cyclic voltammetry and quartz crystal microgravimetry study of autocatalytic copper(II) reduction by cobalt(II) in ethylenediamine solutions

Cyclic voltammetry (CV) and electrochemical quartz crystal microgravimetry (EQCM) were used to study the reactions in a new type autocatalytic (electroless) copper deposition system using cobalt(II)–ethylenediamine complex as a reducing agent. The rates of Co(II) oxidation and Cu(II) reduction (partial reactions of the autocatalytic process) as well as those of Cu anodic dissolution and Co(III) reduction were measured both in separate Co(II)–En, Cu(II)–En, and in complete electroless plating systems (pH 6–8) as a function of Cu potential (from ?0.4 to 0.05 V vs. SHE), in unstirred solution and under flow-through (wall-jet) conditions. The experimental results show that the autocatalytic process results from a coupling of partial electrochemical reactions of Co(II) oxidation and Cu(II) reduction on the Cu surface, some deviations from partial reactions additivity being explained by ligand (En) concentration changes at the Cu surface in the separate solutions of Co(II) and Cu(II) and in the complete system. The Co(II) oxidation rate increases with the solution pH alongside the increase in CoEn₃²⁺ complex concentration in the solution. The partial reaction rate increases remarkably at solution flow conditions, this effect being related both to the transport of reacting Cu(II) and Co(II) species to the electrode, and to the removal of Co(III) species from the Cu surface. Chloride ions possibly act as a bridge between reacting complex species and the Cu electrode.     

口腔鳞癌中VEGF和MMP-2的表达及其相关性

目的：探讨MMP-2、VEGF在口腔鳞状细胞癌（OSCC）中的表达、两者相关性及其作用。方法：采用免疫组化法检测MMP-2和VEGF在86例OSCC和20例正常非肿瘤组织中的表达情况及两者的相关性。结果：MMP-2和VEGF在OSCC中的阳性表达率分别为85．9％和88．4％，均高于正常组织的10．0％，15．0％；差异均有显著性差异如〈0．01）：MMP-2和VEGF在OSCC中的表达呈正相关（CAMMA值0．476，p=0．007）。结论：MMP-2和VEGF在OSCC中呈过表达，二者之间的相互作用与OSCC增殖、侵袭和转移密切相关。     

数字化口腔修复（20）--数字化全口覆盖义齿的临床应用（附病例报告）

目的：利用计算机辅助设计与制造（ computer aided design／computer aided manufacturing,CAD／CAM）技术,制作数字化的全口覆盖义齿并评价其修复效果。方法：临床病例为上下颌各残余经根管治疗和金属根帽修复的两个残根的无牙颌患者,按照传统全口义齿的临床操作完成印模,哥特式弓记录轨迹,面弓转移牙合记录,上牙合架,再经过扫描牙合架上的模型,在CAD虚拟牙合架上完成虚拟排牙和虚拟咬合运动,CAM切削基托蜡型和成品人工牙,最后将人工牙安放在切削基托蜡型咬合面的基底上。经过传统试排牙和三维数字化试排牙后,患者满意后,常规充胶,完成全口覆盖义齿制作并戴牙。结果：数字化全口覆盖义齿的固位和稳定良好,美观,能够正常行使咀嚼功能。结论：数字化全口覆盖义齿与传统的全口覆盖义齿比较,具有简单数字化排牙工艺,牙合设计精确,形成的牙合曲线完美,基托厚薄一致,患者适应期短的优点,是今后全口义齿制作的发展方向。     

Probiotic intervention influences the salivary levels of Matrix Metalloproteinase (MMP)-9 and Tissue Inhibitor of metalloproteinases (TIMP)-1 in healthy adults

ObjectiveTo study the effect of orally administered Bifidobacterium animalis subsp. lactis BB-12 and Lactobacillus rhamnosus GG on the salivary levels of Matrix Metalloproteinases (MMP)-8, MMP-9 and of Tissue Inhibitor of Metalloproteinases (TIMP)-1 in healthy adults. Furthermore, the correlations between MMP-8, MMP-9 and TIMP-1 and plaque and gingival indices, salivary mutans streptococci and lactobacilli counts, and stimulated saliva secretion rate were analysed.DesignThe salivary samples originated from a randomized controlled trial where healthy student volunteers consumed probiotic or placebo lozenges twice a day for four weeks. The saliva samples were collected and clinical parameters measured at the baseline and at the end of the original study. For this study, the salivary levels of MMP-8, MMP-9 and TIMP-1 were analysed with immunofluorometric assay (IFMA) and enzyme-linked immunosorbent assay (ELISA).ResultsIn the probiotic group (n = 29), salivary MMP-9 levels increased (p < 0.01) and TIMP-1 levels decreased (p < 0.01) significantly during the intervention. Furthermore, MMP-9/TIMP-1 ratio differed significantly from the baseline level (p < 0.01). These changes were not observed in the control group (n = 31). In the whole data, salivary MMP-9 and gingival index correlated (r = 0.260, p < 0.05 at baseline and r = 0.354, p < 0.01 at the end of the study). Intergroup differences or correlations with other clinical parameters were not found. Probiotic consumption did not affect the saliva flow rate.ConclusionsIncreased MMP-9 and decreased TIMP-1 levels in saliva may indicate that probiotics have immunomodulatory effects in the oral cavity. Furthermore, increased salivary MMP-9 levels may be an indication of the defensive potential of matrix metalloproteinases.     

The relationship between phenylthiocarbamide (PTC) and 6-n-propylthiouracil (PROP) taster status and taste thresholds for sucrose and quinine

OBJECTIVE: The aim of this study was to investigate the relationship of taster status with taste detection and recognition thresholds for sucrose and quinine. DESIGN: Sixty-nine subjects (35 men and 34 women; mean age, 23.9+/-1.2 years) were included. Stimulus fluids were prepared, one each for phenylthiocarbamide (PTC), 6-n-propylthiouracil (PROP), sucrose and quinine HCl. In each series, successive solutions, which comprised a total of 15 grades, differed by 0.25log units of the molar concentration. Two concentrations of NaCl (0.32 and 1.0 M) were prepared. The subjects were classified as nontasters and tasters using their PTC and PROP perceptions. Tasters were classified as medium-tasters and supertasters by the ratio of perceived bitterness of above-threshold PROP relative to the perceived saltiness of NaCl (PROP ratio). Taste detection and recognition thresholds for sucrose and quinine were determined by standard two-alternative forced choice trials. A Student's t-test, a Pearson's correlation analysis and linear contrasts in a one-way analysis of variance (ANOVA) were used. RESULTS: The percentages of nontaster, medium-taster and supertaster were 13, 70 and 17%, respectively. There were no significant gender differences in the taste detection and recognition thresholds for sucrose and quinine. The threshold for PTC and PROP showed significant correlations with taste threshold for quinine. Linear contrast in one-way ANOVA showed that the greater the value of PROP ratio, the more sensitive to sweet and bitter tastes (p<0.001). CONCLUSION: The PTC and PROP taster status is closely related with taste detection and recognition thresholds for sucrose and quinine.     

Erythropoietin (rhEPOa) promotes endothelial transdifferentiation of stem cells of the apical papilla (SCAP)

ObjectiveMesenchymal stem cells (MSCs) have attracted worldwide attention for their capacity to repair damaged tissue, immunosuppression, ability to differentiate into several cell types and their secretome. Earlier studies have demonstrated their angiogenic potential in vitro and in vivo. However, little is known regarding pro-angiogenic inducers of stable endothelial transdifferentiation of MSCs. Here, we employed human MSCs from the Apical Papilla (SCAP) and investigated whether recombinant human erythropoietin-alpha (rhEPOa) could act as such inducer.DesignCultured SCAP cells were exposed to rhEPOa and assessed for cell growth kinetics, viability and morphology, as well as their capacity to form capillary tubule structures in selected microenvironments. RT-PCR was used to monitor endothelial markers and activation of EPO/EPOR pathway signaling components; while gelatin zymographies to assess activation of MMP-2.ResultsrhEPOa treatment initially (48 h) accelerated cell proliferation and allowed SCAP to sprout micro-tubular structures. Morphological and biochemical differentiation was accompanied by activation of MMP-2 and upregulation of PECAM-1, VEGFR2, vWF and VE-cadherin/CDH5. SCAP expressed the cognate EPO-R, while rhEPOa-treated SCAP exhibited higher expression of molecules involved in EPO/EPOR pathway (EPOR and JAK2).ConclusionrhEPOa is capable of promoting endothelial transdifferentiation of SCAP which may be of clinical value in treating of ischemic disorders.     

Facial morphology and occlusion of a patient with fibrodysplasia ossificans progressiva (FOP): a case report

Fibrodysplasia ossificans progressiva (FOP) is a rare disease characterized by postnatal heterotopic ossification (HO). When HO affects the masticatory muscles, mouth opening becomes restricted. This paper presents the changes in facial morphology and occlusion of a patient with FOP who was followed from the age of 8 to age 21. At the initial examination, he had a severely protruded maxilla and Angle Class II Division 1 malocclusion. His mouth opening was restricted (5.0 mm). He had a large overjet and this enabled him to clean his teeth and to eat. Orthodontic correction was not planned, and his facial growth was closely followed with attention to his oral hygiene. The maxillary protrusion and a low mandibular plane angle became more prominent as the patient aged. His mandible rotated in a counterclockwise direction. His molars had delayed eruption or were impacted and seven were extracted. His mouth opening increased slightly and his oral hygiene improved to excellent.     

Sulfate and CO surface complexes formation with upd copper on Pd(111) and Pt(111) electrode surfaces: abnormal vibrational frequency shifts of CO and sulfate during upd processes

Carbon monoxide (CO) and sulfuric acid anion contacted with underpotential deposition (upd) copper on Pd(111) and Pt(111) electrode surfaces in 0.5 M H₂SO₄ solution were studied by cyclic voltammetry (CV) and in situ infrared reflection absorption spectroscopy (IRAS). CO was stabilized on copper covered Pd(111) and Pt(111) electrode surfaces. Both CO and (bi)sulfate molecules that were stabilized with copper, showed no potential dependent frequency shift in band center position over a certain potential range. Copper (bi)sulfate or copper carbonyl surface metal complexes are formed on Pd(111) and Pt(111) electrode surfaces in the potential range. The copper atoms in the upd potential range on Pd(111) or Pt(111) electrode do not form an ordinal metal ds band structure, but exhibit insulator like characteristics, due to excess positive charge of copper and ionic pseudo-copper metal complex formation on the surface.     

富血小板血浆用于牙周组织再生的研究Ⅰ、PRP的提取及对PDLFs增殖的影响

目的建立富血小板血浆(PRP)提取的方法,以探讨作为自身复合生长因子来源的可行性,并研究其对牙周膜成纤维细胞(PDLFs)增殖的影响.方法利用二次离心(1000 rpm×15 min;3000 rpm×8 min)分离全血,获得PRP.将PRP设5个浓度组(5%,10%,20%,30%,50%),与对照组(不含PRP)比较,观察它们对PDLFs增殖的影响.结果所获得的血小板浓度均超过全血的4倍,实验组各浓度的PRP均可促进PDLFs增殖,实验组间及与对照组相比差异均具有显著性(p<0.01).当PRP浓度在5%～30%时促增殖作用呈剂量依赖性.结论二次离心法是一种简单易行的提取PRP的方法.PRP可促进PDLFs的增殖.     

复发性口疮与SOD活性关系的探讨

目的 :研究复发性口疮 (RAS)与超氧化物歧化酶 (SOD)活性的关系。方法 :选择复发性口疮患者 6 3例 ,健康成人 6 8例 ,取耳血加入蒸馏水中制成溶血液 ,用 72 2S分光光度计来测定红细胞超氧化物歧化酶活性。结果 :复发性口疮患者的SOD较健康人的SOD明显低下 (P <0 .0 1)。有显著性差异。男女之间SOD值无变化 ,(P >0 .0 5 ) ;无统计学意义。结论 :氧自由基在RAS的发病过程中可能是多因素致病的环节之一。     

放线共生放线杆菌表面相关物质对人牙周膜成纤维细胞在牙根片上附着的影响

目的：观察放线共生放线杆菌表面相关物质对人牙周膜成纤维细胞在牙根片上附着的影响。方法：应用细胞计数法和扫描电镜观察法。结果：100mg/L组对人牙周膜成纤维细胞在根面附着有明显抑制作用,表现为正常牙根片上附着细胞数明显少于对照组（P＜0．05）;扫描电镜显示细胞生长数量减少,细胞突起伸展不充分。结论：此物质可抑制人牙周膜成纤维细胞在牙根面上的附着。     

The different effects of intraoral vertical ramus osteotomy (IVRO) and sagittal split ramus osteotomy (SSRO) on mandibular border movement

Objectives: This study investigated the different effects of intraoral vertical ramus osteotomy (IVRO) and sagittal split ramus osteotomy (SSRO) on mandibular border movement.

Methods: The participants included 22 patients receiving IVRO and 22 patients receiving SSRO who were treated at Okayama University Hospital. Their mandibular border movement was evaluated in three dimensions with 6° of freedom using an optical recording system.

Results: A strong correlation between condylar and lower incisor movement was observed during maximum jaw protrusion and laterotrusion. Significant improvements in condylar and lower incisor movement were detected after orthognathic surgery during maximum jaw protrusion and laterotrusion in the IVRO group and during maximum jaw protrusion in the SSRO group.

Discussion: IVRO likely achieves greater improvement in jaw movement than SSRO. Therefore, the application of IVRO could be considered in the treatment of patients with jaw deformities featuring temporomandibular joint problems.     

D-Bite (Digital-Bite): tecnica di costruzione CAD/CAM

Objectives

To manufacture an occlusal splint based on CAD/CAM technology.

Materials and methods

Plaster casts made from oral impressions were scanned with CAD/CAM technology. The CAD/CAM device employed was a structured light-based scanner. CAD generates a 3D digital image that can be used to design the splint. During the CAM phase, the D-Bite (Digital Bite) was created from a block of polymethyl methacrylate (PMMA) with a thickness of about 20 mm.

Results

The production of a digitally designed D-Bite (Digital Bite). The D-Bite manufacturing technique is standardized thanks to computer-assisted procedures.

Conclusions

The D-Bite manufactured with CAD/CAM technology provided excellent biological and esthetic results, and the manufacturing technique was simple and rapid.     

The oxidation of β-nicotinamide adenine dinucleotide (NADH) at poly(aniline)-coated electrodes: Part II. Kinetics of reaction at poly(aniline)–poly(styrenesulfonate) composites

Poly(aniline)–poly(styrenesulfonate) composite-coated glassy carbon electrodes are shown to produce a stable, reproducible amperometric response to NADH in citrate–phosphate buffer at pH 7. These responses have been studied as a function of electrode potential, film thickness and both NADH and NAD⁺ concentration. The results show that the oxidation of NADH occurs throughout the whole of the film and that NAD⁺, the reaction product, reversibly inhibits the reaction. Rate constants for the different processes have been obtained by kinetic modelling and compared with those previously determined for poly(aniline)–poly(vinylsulfonate) films. Preliminary comparisons imply that diffusion within ‘pores’ in these poly(aniline) composite matrices is important in determining the magnitude of the amperometric responses.     

放线共生放线杆菌表面相关物质对人牙龈成纤维细胞DNA合成和细胞周期的影响

目的观察放线共生放线杆菌表面相关物质对人牙龈成纤维细胞的DNA合成和细胞周期的影响。方法应用流式细胞仪技术。结果100mg/L组明显抑制细胞DNA合成，细胞增殖指数（S+G2M）%降低（P<0.05）。结论此物质不仅抑制细胞的分裂、增殖，而且还抑制细胞的DNA合成。     

Acute localized exanthematous pustulosis (ALEP) caused by Ibuprofen. A case report

Acute generalized exanthematic pustulosis (AGEP) is characterized by a generalized rash and sterile disseminated, sometimes coalescing subcorneal pustules. It occurs in body flexures such as the inguinal folds and intertriginous areas. The acute onset of disease is accompanied by malaise, fever >38 degrees C and peripheral granulocytosis. We report on a female patient who according to the criteria of AGEP was diagnosed as having acute localized exanthematic pustulosis (ALEP) on the face.