Determination of seven polycyclic aromatic hydrocarbons in water by dispersive liquid-liquid microextraction based on solidification of floating organic droplet with gas chromatography-mass spectrometry / 上海预防医学

Objective To develop a new method for the simultaneous determination of seven polycyclic aromatic hydrocarbons(PAHs)in water by dispersive liquid-liquid microextraction based on solidification of floating organic droplet(DLLME-SFO)with gas chromatography-mass spectrometry(GC-MS). Methods The experimental conditions of DLLME-SFO were determined with dodecanol as extractant solvent, methanol as dispersive solvent, inonic strength increased by adding 8% NaCl. After vortexed for 1 min and centrifuged at 4 000 r/min for 5 min, the water sample was cooled down in an ice bath till dodecanol became solid and formed a small ball. Then the solidified dodecanol phase was transferred, and directly detected by GC-MS method after it melted. Results Good linearities were obtained for the seven polycyclic aromatic hydrocarbons within the range of 5 μg/L-200 μg/L. The correlation coefficients were above 0.996. The detection limits ranged from 1.6 ng/L to 3.2 ng/L. The average recoveries ranged from 86.2% to 105% and the RSDs from 3.8% to 9.4%. Conclusion The method is sensitive, fast and simple. It has the advantage of little organic solvent consumption, which is friendly to environment and suitable for the detection of seven PAHs in water.

Development of double-component rapid curing bioadhesive / 生物医学工程学杂志

Mussel foot proteins (MFp) could cure rapidly under water and adhere to different substrates. It has broad application prospects as an biocompatible bioglue. The soluble recombinant SUMO-MFp fusion protein (SFp3) was efficiently expressed in , and about 5% of tyrosine of SFp3 were converted into DOPA by using mushroom tyrosinase. The adhesion strength of the mixture of DOPA-containing SFp3 (DSFp3) and hyaluronic acid (MW = 1 500 kD) was more than twice that of the cyanoacrylate-based tissue adhesives, Dermabond , and it reached 52% of its maximal strength within 5 minutes on cowhide. A layer-by-layer assembly of hyaluronic acid with DSFp3 was observed to form compact sheet structures through biofilm interferometry assay and scanning electron microscopy. This work provides a solution and theoretical basis for the low adhesion strength and slow curing of protein-based bioglue.

Preparation of chrysin solid lipid nanoparticles and their pharmacokinetic behaviors / 中成药

AIM To prepare chrysin solid lipid nanoparticles and to evaluate their pharmacokinetic behaviors.METHODS The particle size,Zeta potential and in vitro release rate of nanoparticles prepared by emulsification uhrasonication-low temperature solidification method were determined.Twelve SD rats were randomly divided into two groups and were intragastrically given suspensions of crude drug and nanoparticles,respectively.HPLC was used for the content determination of chrysin in plasma,after which blood drug concentration-time curves were drawn,and pharmacokinetic parameters were calculated.RESULTS The obtained nanoparticles demonstrated the particle size of (207.15 ±30.59) nm,PDI of (0.224 ±0.067) and Zeta potential of (-34.8 ±5.9) mV,respectively,whose accumulative release rate reached 84.36％ within 36 h.Their Cmax [(9.04 ± 1.52) μg/mL] and AUC0～t,[(33.67 ± 3.47) μg · h/mL] were much higher than those of the crude drug (P ＜ 0.01).CONCLUSION Solid lipid nanoparticles can promote the oral absorption and bioavailability of chrysin,with significant sustained-release characteristics.

Preparation of Salinomycin Nanostructured Lipid Carriers and Formulation Optimization / 中国药房

OBJECTIVE: To prepare Salinomycin nanostructured lipid carriers (Sal-NLCs) and optimize its formulation. METHODS: Sal-NLCs was prepared by emulsion evaporation-low temperature solidification method. Using particle size, Zeta potential, encapsulation efficiency and drug loading as evaluation indexes, central composite design-response surface methodology was used to optimize the amount of Sal, the ratio of solid lipid glyceryl bisstearate to liquid lipid glyceryl octanoate in oil phase, ratio of surface active agent polyoxyethylene 35 castor oil (EL) to polyethylene glycol-15-hydroxy stearate (HS 15), the amount of polyoxyethylene (40) stearate (P40). The morphology, particle size, polydispersity index (PDI), Zeta potential, encapsulation efficiency, drug loading and in vitro release mechanism of Sal-NLCs were investigated. RESULTS: The optimal prescription was as follows as Sal 0. 86 mg, glyceryl bisstearate 40.70 mg, glyceryl octanoate 11.30 mg, EL 44.05 mg, HS15 7.95 mg, P40 3.8 mg. Prepared Sal-NLCs was round-like and dispersed evenly. The particle size, PDI, Zeta potential, encapsulation efficiency and drug loading of prepared Sal-NLCs were(81.81 ± 2.60) nm, 0.183 ± 0.042, (-24.9 ± 3.4) mV,(94.35 ± 1.50)％ and (1.47 ±0.04)％ (n=5), respectively.24 h accumulative release rate was (99.81 ± 3.90)％ (n=3).Drug release behavior was in line with Higuchi model, and relative error of particle size, Zeta-potential, encapsulation efficiency and drug loading to predicted value of model were all lower than 4％. CONCLUSIONS: Sal-NLCs with sustained-release effect is prepared successfully according to optimized formulation, and its quality meets the expected standard.

Preparation and Transdermal Absorption in vitro of Piroxicam Nanostructured Lipid Carrier / 中国药师

Objective: To prepare piroxicam nanostructured lipid carrier and investigate its transdermal absorption behavior in vitro. Methods:Piroxicam nanostructured lipid carrier was prepared by a melt-emulsion ultrasonication and low temperature-solidifica-tion method. The physicochemical properties such as appearance, morphology, particle size distribution, PdI and zeta potential of pi-roxicam nanostructured lipid carrier were evaluated. The transdermal absorption in vitro was investigated using Franz diffusion cells. Results:Piroxicam nanostructured lipid carrier was clear and transparent with small spherical shape as seen under a transmission elec-tron microscope. The particle size distribution, PdI and zeta potential was (106. 4 ± 31. 6) nm, (0. 217 ± 0. 07) and ( -31. 6 ± 2. 5) mV, respectively. Piroxicam nanostructured lipid carrier had higher cumulative transdermal amount in 12 h than piroxicam solution. Conclusion:The nanostructured lipid carrier can remarkably improve piroxicam permeation into skin, which provides reference for the new dosage form for the topical use of piroxicam.

Preparation of mesoporous silica nanoparticles in different pore size and its use in the solidification of sirolimus loaded self-microemulsifying drug delivery system / 药学学报

The mesoporous silica nanoparticles (MSN) in different pore size and sirolimus (SRL) loaded self-microemulsifying drug delivery system (SMEDDS) were prepared. The results in morphology were collected by scanning electron microscope, transmission electron microscope, small-angle X-ray diffraction, and N2 adsorption-desorption. The results showed that the prepared MSN has ordered nanochannels with a pore size of 6.3, 8.1, 10.8 nm, respectively. The particle size of SRL-SMEDDS were measured by particle sizing system, which was 20.6±1.3 nm. The stirring method was developed to prepare SRL-SMEDDS-MSN. It was found that the optimal ratio of SRL-SMEDDS to MSN was 2:1, while the drug loading rate was near 0.83%, and the flow properties of SRL-SMEDDS-MSN were of good condition. The differential scanning calorimetry results proving a molecular or amorphous dispersed state of SRL in MSN while the suspension experiment has shown great reconstitution properties of SRL-SMEDDS-MSN. There is no significant influence on maximum drug release rate of different pore size of SRL-SMEDDS-MSN in 250 mL water within 2 h, while the results of the first 40 min have an obvious difference. Above all, MSN might provide a new strategy for the solidification of SMEDDS.

Development and characterization of oriented scaffolds derived from cartilage extracellular matrix / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study aimed to prepare oriented scaffolds derived from a cartilage extracellular matrix (CECM) and to investigate their physicochemical property and compatibility with adipose-derived stem cells (ADSCs).</p><p><b>METHODS</b>A fresh porcine articular cartilage was cut into pieces. Cartilage nanofibers with diameters of 50-500 nm were collected through homogenization and centrifugation. These nanofibers were then decellularized by using Triton X-100 to produce 6% CECM. The oriented scaffolds derived from the nanoscale CECM were fabricated through unidirectional solidification and lyophilization. Afterward, these scaffolds were crosslinked. The physical and chemical performances and cell compatibility of CECM-oriented scaffolds were evaluated.</p><p><b>RESULTS</b>The cross-sections of the scaffolds contained homogeneous reticular porous structures with nanofibers on the walls of the pores, and the longitudinal sections revealed vertical tubular structures. Hematoxylin-eosin staining revealed that the scaffolds were red without blue. Toluidine blue, safranin O, and Sirius red staining showed positive results. The porosity, water absorption rate, and vertical compressive elastic modulus of the scaffolds were 95.455%±0.910%, 95.889%±1.071%, and (40.208±5.097) kPa, respectively.</p><p><b>CONCLUSIONS</b>The components of the oriented scaffolds derived from CECM are similar to those of native cartilage with favorable biocompatibility. The porous structures and sizes of the scaffolds are suitable for the adhesion, proliferation, and infiltration of ADSCs. The oriented scaffolds derived from CECM are relatively optimal for cartilage tissue engineering. 
.</p>

Studies on sirolimus self-microemulsifying drug delivery system and its solidification / 药学实践杂志

Objective To screen the formulation of self-microemulsifying drug delivery system (SMEDDS) for sirolimus (SRL) and prepare the SRL-SMEDDS pellets.Methods Co-emulsifier,oil phase and emulsifier were chosen by solubility test and ternary phase diagrams,central composite design and response surface method were adopted to screen and optimize the preparation and formulation of liquid SRL-SMEDDS.The selected liquid SRL-SMEDDS formulations were prepared into pellets by extrusion-spheronization method.Results The final pellets from liquid SRL-SMEDDS formulation :SRL 0.4%,Labrafil M1944CS 9.3%,Cremophor EL 15.9%,Transcutol P 8.0%,MCC 49.8%,lactose 13.3%,CMS-Na 3.3%.Dissolution test showed superphosphate (SSP) in the dissolution water is much greater than the commercially available sirolimus tablets ;while in 0.4% SDS solution,the two formulations showed similar dissolution.Conclusion SMEDDS can improve the dissolution of SRL in v itro.

Application and development trend of nanosuspension technology in Chinese materia medica preparation / 中草药

Nanosuspension technology has provided a new method for improving the solubility and bioavailability of the effective components and the effective parts in Chinese materia medica (CMM). It is one of the effective ways to realize the modernization and internationalization in the application and development of CMM. This article mainly summarizes the preparation method, curing research, application of CMM nanosuspension drug delivery system, analyzes the existing problems, and puts forward some ideas, in order to promote the development and perfection of nanosuspension technology in CMM, and expand the scope of application of CMM.

Caracterização de blocos cerâmicos acústicos produzidos com incorporação de lodo de lavanderia têxtil / Characterization of acoustic ceramic blocks produced with incorporating textile laundry sludge

Características físicas (absorção de água), mecânicas (resistência à compressão), de toxicidade e de superfície (microscopia eletrônica de varredura) foram avaliadas em blocos cerâmicos acústicos, fabricados por meio do processo de solidificação/estabilização (S/E), a partir da incorporação de lodo proveniente de estação de tratamento de efluentes têxteis. Os blocos cerâmicos acústicos foram produzidos com incorporação de 5, 10, 15, 20, 25, 30 e 35% de lodo têxtil na massa de argila, bem como o bloco controle. Os resultados indicaram a porcentagem de 20% de lodo como o limite para fornecer material com características de acordo com os padrões estabelecidos pela legislação brasileira. O processo de S/E foi eficiente no aproveitamento/tratamento do lodo têxtil, uma vez que permitiu a imobilização dos poluentes na massa de argila, os quais não foram lixiviados, tampouco solubilizados.

Physical characteristics (water absorption), mechanical (compression length), of toxicity and surface (scanning electron microscopy) were evaluated in acoustic ceramic blocks, manufactured by the process of solidification/stabilization (S/S) from the incorporation of sludge from a textile wastewater treatment plant. Acoustic ceramic blocks were produced by incorporating of 5, 10, 15, 20, 25, 30 and 35% of textile sludge in the clay mass/material as well as the control block. The results indicated the percentage of 20% of sludge, as the limit to provide materials with good characteristics of accordance with the standards established by Brazilian law. The S/S process was efficient in the recovery/treatment of the textile sludge, as it allowed the immobilization of pollutants in the clay mass/material, which have not been leached, neither solubilized.

Preparation and in vitro Evaluation of Simvastatin-loaded Nanostructured Lipid Carriers / 中国药师

To prepare simvastatin nanostructured lipid carriers ( simvastatin-NLCs) . Methods:The simvastatin-NLCs were prepared by melt-emulsion ultrasonication and low temperature-solidification methods. Using the particle size, polydispersion in-dex, encapsulation efficiency and drug loading as the idices, the ratio of solid to liquid, lipid concentration, ratio of surfactant to cosur-factant, emulsifier concentration and drug concentration were optimized. The optimized simvastatin-NLCs were characterized for the en-capsulation efficiency, particle size, zeta potential and morphology. In vitro drug release behavior and stability of NLCs were also stud-ied. Results:The optimized simvastatin-NLCs formula was as follows:the concentration of simvastatin, cetyl palmitate, Miglyol? 812, soy lecithin and solutol HS15? was 0. 5%, 1. 5%, 4. 5%, 2. 5% and 1. 5%, respectively. The particle size and zeta potential of NLCs was (102. 2 ± 42. 1) nm and ( -33. 1 ± 4. 1) mV, respectively. The simvastatin-NLCs were found to be small and spherical with smooth surface under a transmission electron microscope. The in vitro release profile indicated that the accumulated release of sim-vastatin reached up to (59. 1 ± 4. 8) % in 24 h. The stability studies showed that simvastatin-NLCs were stable in 3 months after stored at 5℃. Conclusion:The formula of simvastatin-NLCs prepared by melt-emulsion ultrasonication and low temperature-solidifica-tion method is feasible.

Progress on solid self-microemulsifying drug delivery system for oral administration / 药学实践杂志

Objective To review the newly developed solid self-microemulsifying drug delivery system (S-SMEDDS).Meth-ods Relevant literatures at home and abroad in recent years were consulted and summarized .Results Solid self-microemulsions car-rier, solidification technology and controlled release formulations were discussed , in order to provide relevant references for improving the bioavailability of water-insoluble drugs and the SMEDDS technology for drug release characteristics .Conclusion The utilization of the solid self-emulsifying drug delivery system could significantly enhance the oral bioavailability of water -insoluble drugs .As a new formulation, S-SMEDDS presented huge potential .

Preparation and in vitro release of lyophilized powder of sorafenib solid lipid nanoparticles / 中国药学杂志

OBJECTIVE: To prepare soraienib solid lipid nanoparticles and investigate its physicochemical properties and in vitro release profile. METHODS: Sorafenib solid lipid nanoparticles were prepared by emulsion evaporation-solidification at low temperature. The morphology was examined by transmission electron microscope. The particle size and Zeta potential were determined by laser granularity equipment. The encapsulation efficiency was detected by Sephadex gel chromatography and HPLC. The in vitro release pro-file of sorafenib solid lipid nanoparticles was studied using dialysis technology. The lyophilized powder of sorafenib solid lipid nanoparticles was prepared by refrigerated air dryer and its material phase was analyzed by DSC. RESULTS: The sorafenib solid lipid nanoparticles assumed spherical shape. The distribution of diameter was even with average particle size of (108.2±7.0) nm. The PDI and Zeta potential were (0.250±0.022) and (-16.4±0.7) mV, respectively. The average encapsulation efficiency was (73.49±1.87)%. The release in vitro accorded with Weibull order model. Equal volume of 15% mannitol was the best protective agent for lyophilized powder of sorafenib solid lipid nanoparticles. The formation of a new material phase was testified by analysis of DSC. CONCLUSION: The method of emulsion evaporation-solidification at low temperature was appropriate for preparation of sorafenib solid lipid nanoparticles. The nanoparticles had stable physical properties and significant sustained-release effect.

Preparation of gambogenic acid loaded nanostructured lipid carriers and its pharmaceutical properties / 中草药

Objective: To prepare and characterize gambogenic acid loaded nanostuctured lipid carrier (GNA-NLC). Methods: GNA-NLC was prepared by emulsion evaporation-low temperature solidification method, and its optimal prescription was selected by orthogonal test design. The characteristics, such as encapsulation efficiency (EE), average diameter, and Zeta potential, were studied. Results: GNA-NLC had a spherical shape with smooth surface with the average diameter of (144.07 ± 1.44) nm, polydispersity index (PI) of 0.24 ± 0.01, Zeta potential of (-28.03 ± 0.29) mV. The EE and drug loading were (84.65 ± 0.98)% and (4.21 ± 0.05)%, respectively. DSC indicated that GNA was dispersed as non-crystalline in matrix. Conclusion: Emulsion evaporation-low temperature solidification method is easy, simple, and feasible to prepare GNA-NLC.

Optimization of solid lipid nanoparticles of silymarin by using Box-Behnken experimental design / 中草药

Objective: To optimize the formulation parameters of solid lipid nanoparticles (SLN) of Silymarin by Box-Behnken experimental design. Methods: A three-factor and three-level Box-Behnken experimental design was employed using emulsion evaporation-low temperature solidification technique to prepare SLN with Silymarin as model drug. Response surface methodology was used to investigate the factors affecting entrapment efficiency (EE), drug loading (DL), and particle size. Binomial mathematical model-optimized formulation was established with EE, DL, and particle size as response values. Results: The optimal formulation was as follows: the amount of glycerol monostearate was 5.05%, the concentration of Poloxamer 188 was 7.25%, and the amount of drug was 15%. Conclusion: The Box-Behnken experimental design could be used to optimize the SLN of silymarin.

Dispersive Liquid-Liquid Microextraction Based on Solidification of Floating Organic Drop with High Performance Liquid Chromatography for Determination of Decabrominated Diphenyl Ether in Surficial Sediments / 分析化学

A method for the determination of decabrominated diphenyl ether(decaBDE) in sediment samples at trace level using dispersive liquid-liquid microextraction based on the solidification of floating organic drop (DLLME-SFO) and high performance liquid chromatography-ultraviolet detector (HPLC-UV) has developed.Based on the data of interactive orthogonal array design, the optimization experimental conditions were obtained with BP artificial neural network model: 1.00 mL methanol as dispersive solvent, 35.0 μL dodecanol as extractive solvent, 10.00% NaCl, pH 5, and extraction in 10 min.The extraction recovery (ER) was 62.22% at the extraction conditions.The proposed method exhibited a wide linear range(3.5-1400 ng/g) with R~2 =0.9921.The limit of detection (LOD) and the limit of quantification (LOQ) of this method were 2.3 pg/g(S/N =2) and 5.6 pg/g(S/N = 5), respectively.The recoveries of real samples at different spiking levels of decaBDE were 104.2%, 98.4% and 97.7%, respectively.Extraction, concentration and separation procedures for decaBDE from the sediment sample were carried out by one step, and hence, the process of DLLME-SFO for decaBDE was shortened.

Avaliação da integridade e da retenção de metais pesados em materiais estabilizados por solidificação / Assessment of integrity and retention of heavy metals in materials stabilized by solidification

A quantidade de resíduos sólidos industriais tem aumentado significativamente em decorrência da industrialização, e o seu gerenciamento adequado é necessário para reduzir o impacto ao meio ambiente e aos ecossistemas. Neste trabalho, foram avaliadas a integridade e a retenção de metais pesados em materiais estabilizados por solidificação. Foi adotado o planejamento completamente aleatorizado com um único fator, ou seja, foram comparadas as médias de quatro tratamentos (A, B, C e D) com 0, 40, 50 e 60 por cento respectivamente de contaminantes e três repetições. Cimento Portland comum, bentonita sódica e hidróxido de cálcio foram usados para estabilizar por solidificação o resíduo sólido sintético contendo óxido de Cd2+, Pb2+ e Cu2+. Pode-se concluir que os tratamentos influenciaram no resultado de lixiviação do cádmio, chumbo e cobre. Os tratamentos mostraram que as concentrações do extrato solubilizado e lixiviado aumentam em função da quantidade de cádmio, chumbo e cobre adicionada. O maior valor encontrado foi para o material proveniente do tratamento D, que apresentou lixiviação igual a 32,815 mg.kg-1 para o cádmio e 29,769 mg.kg-1 para o chumbo. Para os ensaios de integridade/durabilidade, constatou-se que o aumento da absorção de água fez com que a resistência à compressão diminuísse. O uso de cimento, de hidróxido de cálcio e de bentonita sódica se mostrou ideal para retenção de metais pesados, evitando a sua lixiviação e a solubilização para o meio ambiente.

As the quantity of hazardous industrial wastes increases significantly owing to rapid industrialization, its appropriate management is required to reduce adverse impacts on humans and ecosystems. This work evaluated the integrity and retention of heavy metals in materials stabilized by solidification. It was adopted a completely randomized design with a single factor, that is, the averages of four treatments were compared (A, B, C and D) with 0, 40, 50 and 60 percent respectively contaminants and three repetitions. Portland cement, bentonita and lime-fly ash binders were used to solidify a synthetic heavy metal sludge containing oxides of Cd2+, Pb2+ e Cu2+. It can be concluded that the treatment influenced the result of leaching of cadmium, lead and copper. The treatments showed that the concentrations of solubilized and leachate extract increase with the amount of cadmium, lead and copper added. The highest price was found in the material from the treatment D, that presented leaching equal to 32.815 mg.kg-1 for cadmium and 29.769 mg.kg-1 for the lead. For the tests of integrity/durability, it was found that increasing the absorption of water has caused resistance to compression decreased. The use of cement, calcium hydroxide and sodium bentonite were ideal for retention of heavy metals, avoiding leaching and solubilization for it's the environment.

Preparation Technology of Curcumine Solid Lipid Nanoparticles / 中国药房

OBJECTIVE:To prepare Curcumine solid lipid nanoparticles(Cur-SLN).METHODS:Cur-SLN was prepared by emulsification evaporation-solidification at low temperature.The formulation of Cur-SLN was optimized by orthogonal experiment with the contents of curcumine,poloxamer 188,docosanoic acid glyceride lecithin used as factors and with entrapment efficiency as index;meanwhile,the appearance,particle size,surface potential,entrapment efficiency and the release profile of curcumine in vitro were studied.RESULTS:The optimized preparation conditions were as follows:the contents of curcumine,poloxamer,docosanoic acid glyceride lecithin were 8 mg,320 mg,140 mg and 320 mg,respectively.The Cur-SLN assumed spherical shape with particle size at(134?5)nm,entrapment efficiency at(67.4?1.3)% and mean surface potential at(-23.5?1.5)mV.The release profile of curcumine in vitro fitted Higuchi equation.CONCLUSION:It is feasible to prepare Cur-SLN by emulsion evaporation-solidification at low temperature,and the study results serve as experimental evidence for developing new curcumine injection.

Computer-aided casting design for implant titanium superstructures / 대한치과보철학회지

STATEMENT OF PROBLEM: It is difficult to obtain a good titanium casting body using the traditional sprue design because of high melting point of Ti, and the low fluidity and high reactivity of molten Ti. PURPOSE: A new sprue design for titanium casting bodies needs more trial and error. In order to decrease the number of trial and error, computer simulation(MAGMASOFT, Magmasoft Giessereitechnologie GmbH, Achen, Germany) was used to optimize sprue design in U-shaped implant superstructures. MATERIAL AND METHOD: Five kinds of sprue were examined for the design of the sprue former for titanium casting: Sprue design A(sprue length 4 mm, rectangular shape, 4 sprues), Sprue design B(sprue length 4 mm, round shape, radius 2 mm, 7 sprues), Sprue design C (sprue length 2 mm, round shape, radius 2 mm, 7 sprues), Sprue design D (sprue length 2 mm, cone shape, large radius 3mm, small radius 2mm, 7 sprues), and Sprue design E( sprue length 2 mm, one unit channel shape). Sprue design F(sprue length 2mm, one unit channel hape) was also examined for the design of the customized sprue former in the Biotan system(Schutz Dental Gmbh, Germany). The casting bodies were taken in Sprue design A, Sprue design D, Sprue design E, and Sprue design F in the Biotan casting system. The numerically predicted defects were compared with the experimental dental castings by the radiographic and sectional view observations. RESULTS: 1. According to the result of computer simulation, turbulence during mold filling was decreased in the sequence of Sprue design F, Sprue design E, Sprue design D, Sprue design C, Sprue design B, and Sprue design A. 2. The calculated solidification time contours indicate that hot spot was moved from the casting body to the sprue button in the sequence of Sprue design A, Sprue design B, Sprue design C, Sprue design D, and Sprue design E. The filling pattern of Sprue design F was similar to that of Sprue design E. 3. The predicted filling pattern shows that less turbulence was found in the customized sprue former than in the standard sprue former. 4. According to the results of the radiographic and cross sectional observations, casting defects less than 1mm were found at the center of a casting body with Sprue design E and Sprue design F. However, larger casting defects of 4mm were found in a casting with Sprue design A. 5. The predicted casting porosity was similar to that of the real casting. CONCLUSION: One unit channel-type and customized sprue former can be recommended. Further research and development of various sprue designs using computer simulation is necessary to optimize casting design, in order to reduce the formation of casting defects in implant titanium superstructures.

Comparative study on the adhesive capabilities of sodium alginate and guar gum as bone adhesives / 中国海洋药物

Objective To comparatively investigate the adhesive capabilities of sodium alginate and guar gum as bone adhesives.Methods The adhesive capabilities were analysed and discussed by measuring their kinetic viscosities,solidification time and the reaction with calcium ions.Results Guar gum had higher kinetic viscosity and could fit to the supply of both ion calcium and non-ion calcium for the bone cure,but its capability of solidification need to be improved.Sodium alginate had higher solubility and its solidification could be finished in short time,but it had lower viscosity and fit only to the non-ion calcium supply.Conclusion Sodium alginate and guar gum are considered to be the potential natural materials of the bone adhesives.