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Sample records for gel clot method

  1. Determination of bacterial endotoxin (pyrogen) in radiopharmaceuticals by the gel clot method. Validation; Determinacao de endotoxina bacteriana (pirogenio) em radiofarmacos pelo metodo de formacao de gel. Validacao

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    Fukumori, Neuza Taeko Okasaki

    2008-07-01

    Before the Limulus amebocyte lysate (LAL) test, the only available means of pirogenicity testing for parenteral drugs and medical devices was the United States Pharmacopoeia (USP) rabbit pyrogen test. Especially for radiopharmaceuticals, the LAL assay is the elective way to determine bacterial endotoxin. The aim of this work was to validate the gel clot method for some radiopharmaceuticals without measurable interference. The FDA's LALTest guideline defines interference as a condition that causes a significant difference between the endpoints of a positive water control and positive product control series using a standard endotoxin. Experiments were performed in accordance to the USP bacterial endotoxins test in the {sup 131}I- m-iodobenzylguanidine; the radioisotopes Gallium-67 and Thallium-201; the lyophilized reagents DTPA, Phytate, GHA, HSA and Colloidal Tin. The Maximum Valid Dilution (MVD) was calculated for each product based upon the clinical dose of the material and a twofold serial dilution below the MVD was performed in duplicate to detect interferences. The labeled sensitivity of the used LAL reagent was 0.125 EU mL{sup -1} (Endotoxin Units per milliliter). For validation, a dilution series was performed, a twofold dilution of control standard endotoxin (CSE) from 0.5 to 0.03 EU mL{sup -1}, to confirm the labeled sensitivity of the LAL reagent being tested in sterile and non pyrogenic water, in quadruplicate. The same dilution series was performed with the CSE and the product in the 1:100 dilution factor, in three consecutive batches of each radiopharmaceutical. The products {sup 131}I-m-iodobenzylguanidine, Gallium-67, Thallium-201, DTPA, HSA and Colloidal Tin were found compatible with the LAL test at a 1:100 dilution factor. Phytate and GHA showed some interference in the gel clot test. Other techniques to determine endotoxins as the chromogenic (color development) and the turbidimetric test (turbidity development), were also assessed to get

  2. Estimativa da incerteza em ensaio de detecção de endotoxina bacteriana pelo método de gelificação Estimation of uncertainty in the detection of bacterial endotoxin by gel-clot method

    Directory of Open Access Journals (Sweden)

    Felipe Rebello Lourenço

    2005-12-01

    sum of false-negative and false-positive result probabilities. From results obtained was verified that the confirmation of LAL sensitivity contributed to the uncertainty in a more significant way (67,6% than the validation of the test (32,4%. Through this simple procedure and data obtained from the confirmation of LAL sensibility and the validation of the test is possible to obtain a reasonable estimation of the uncertainty of the detection of bacterial endotoxins by gel-clot test.

  3. An automated method for fibrin clot permeability assessment.

    Science.gov (United States)

    Ząbczyk, Michał; Piłat, Adam; Awsiuk, Magdalena; Undas, Anetta

    2015-01-01

    The fibrin clot permeability coefficient (Ks) is a useful measure of porosity of the fibrin network, which is determined by a number of genetic and environmental factors. Currently available methods to evaluate Ks are time-consuming, require constant supervision and provide only one parameter. We present an automated method in which drops are weighed individually, buffer is dosed by the pump and well defined clot washing is controlled by the software. The presence of a straight association between drop mass and their dripping time allows to shorten the measurement time twice. In 40 healthy individuals, Ks, the number of drops required to reach the plateau (DTP), the time to achieve the plateau (TTP) and the DTP/TTP ratio (DTR) were calculated. There was a positive association between Ks (r = 0.69, P Ks (r = -0.55, P Ks (r = 0.70, P < 0.0001 for the manual method and r = 0.76, P < 0.0001 for the automated method), fibrinogen (r = -0.58, P < 0.0001) and C-reactive protein (CRP) (r = -0.47, P < 0.01). The automated method might be a suitable tool for research and clinical use and may offer more additional parameters describing fibrin clot structure.

  4. Effects of unidirectional flow shear stresses on the formation, fractal microstructure and rigidity of incipient whole blood clots and fibrin gels

    Science.gov (United States)

    Badiei, N.; Sowedan, A.M.; Curtis, D.J.; Brown, M.R.; Lawrence, M.J.; Campbell, A.I.; Sabra, A.; Evans, P.A.; Weisel, J.W.; Chernysh, I.N.; Nagaswami, C.; Williams, P.R.; Hawkins, K.

    2015-01-01

    Abstract Incipient clot formation in whole blood and fibrin gels was studied by the rheometric techniques of controlled stress parallel superposition (CSPS) and small amplitude oscillatory shear (SAOS). The effects of unidirectional shear stress on incipient clot microstructure, formation kinetics and elasticity are reported in terms of the fractal dimension (df) of the fibrin network, the gel network formation time (TGP) and the shear elastic modulus, respectively. The results of this first haemorheological application of CSPS reveal the marked sensitivity of incipient clot microstructure to physiologically relevant levels of shear stress, these being an order of magnitude lower than have previously been studied by SAOS. CSPS tests revealed that exposure of forming clots to increasing levels of shear stress produces a corresponding elevation in df, consistent with the formation of tighter, more compact clot microstructures under unidirectional flow. A corresponding increase in shear elasticity was recorded. The scaling relationship established between shear elasticity and df for fibrin clots and whole blood confirms the fibrin network as the dominant microstructural component of the incipient clot in terms of its response to imposed stress. Supplementary studies of fibrin clot formation by rheometry and microscopy revealed the substantial additional network mass required to increase df and provide evidence to support the hypothesis that microstructural changes in blood clotted under unidirectional shear may be attributed to flow enhanced thrombin generation and activation. CSPS also identified a threshold value of unidirectional shear stress above which no incipient clot formation could be detected. CSPS was shown to be a valuable haemorheological tool for the study of the effects of physiological and pathological levels of shear on clot properties. PMID:25624413

  5. Effects of unidirectional flow shear stresses on the formation, fractal microstructure and rigidity of incipient whole blood clots and fibrin gels.

    Science.gov (United States)

    Badiei, N; Sowedan, A M; Curtis, D J; Brown, M R; Lawrence, M J; Campbell, A I; Sabra, A; Evans, P A; Weisel, J W; Chernysh, I N; Nagaswami, C; Williams, P R; Hawkins, K

    2015-01-01

    Incipient clot formation in whole blood and fibrin gels was studied by the rheometric techniques of controlled stress parallel superposition (CSPS) and small amplitude oscillatory shear (SAOS). The effects of unidirectional shear stress on incipient clot microstructure, formation kinetics and elasticity are reported in terms of the fractal dimension (df) of the fibrin network, the gel network formation time (TGP) and the shear elastic modulus, respectively. The results of this first haemorheological application of CSPS reveal the marked sensitivity of incipient clot microstructure to physiologically relevant levels of shear stress, these being an order of magnitude lower than have previously been studied by SAOS. CSPS tests revealed that exposure of forming clots to increasing levels of shear stress produces a corresponding elevation in df, consistent with the formation of tighter, more compact clot microstructures under unidirectional flow. A corresponding increase in shear elasticity was recorded. The scaling relationship established between shear elasticity and df for fibrin clots and whole blood confirms the fibrin network as the dominant microstructural component of the incipient clot in terms of its response to imposed stress. Supplementary studies of fibrin clot formation by rheometry and microscopy revealed the substantial additional network mass required to increase df and provide evidence to support the hypothesis that microstructural changes in blood clotted under unidirectional shear may be attributed to flow enhanced thrombin generation and activation. CSPS also identified a threshold value of unidirectional shear stress above which no incipient clot formation could be detected. CSPS was shown to be a valuable haemorheological tool for the study of the effects of physiological and pathological levels of shear on clot properties.

  6. Highly Effective DNA Extraction Method from Fresh, Frozen, Dried and Clotted Blood Samples

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    Jaleh Barar

    2011-09-01

    Full Text Available Introduction: Today, with the tremendous potential of genomics and other recent advances in science, the role of science to improve reliable DNA extraction methods is more relevant than ever before. The ideal process for genomic DNA extraction demands high quantities of pure, integral and intact genomic DNA (gDNA from the sample with minimal co-extraction of inhibitors of downstream processes. Here, we report the development of a very rapid, less-hazardous, and high throughput protocol for extracting of high quality DNA from blood samples. Methods: Dried, clotted and ethylene diamine tetra-acetic acid (EDTA treated fresh and frozen blood samples were extracted using this method in which the quality and integrity of the extracted DNA were corroborated by agarose gel electrophoresis, PCR reaction and DNA digestion using restricted enzyme. The UV spectrophotometric and gel electrophoresis analysis resulted in high A260/A280 ratio (>1.8 with high intactness of DNA. Results: PCR and DNA digestion experiments indicated that the final solutions of extracted DNA contained no inhibitory substances, which confirms that the isolated DNA is of good quality. Conclusion: The high quality and quantity of current method, no enzymatic processing and accordingly its low cost, make it appropriate for DNA extraction not only from human but also from animal blood samples in any molecular biology labs.

  7. A Simple, Inexpensive and Safe Method for DNA Extraction of Frigid and Clotted Blood Samples

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    Nasrin Mohammadi

    2015-07-01

    Full Text Available Background: Extraction of blood genomicDNAis one of the main approaches for clinical and molecular biology studies. Although several methods have been developed for extraction of blood genomic DNA, most of these methods consume long time and use expensive chemicals such as proteinase K and toxic organic solvent such as phenol and chloroform. The objective of this study was to developed easy and safe method forDNAextraction from clotted and frozen whole blood. This method has many advantages: time reducing, using inexpensive materials, without phenol and chloroform, achieving of high molecular weight and good quality genomicDNA.Materials and Methods: DNA extraction was performed by two methods (new and phenol-chloroform method. Then quantity and quality parameters were evaluated by 1% agarose gel electrophoresis, Nano drop analysis and efficiency of Polymerase Chain Reaction (PCR.Results: Extracted DNA from 500μL of blood samples were 457.7ng/μl and 212ng/μL and their purity (OD260/OD280 were 1.8 and 1.81 for new recommended and phenol–chloroform methods respectively. The PCR results indicated that D16S539 and CSF1PO loci were amplified.Conclusion: These results shown that this method is simple, fast, safe and most economical.

  8. A Fictitious Domain Method for Resolving the Interaction of Blood Flow with Clot Growth

    Science.gov (United States)

    Mukherjee, Debanjan; Shadden, Shawn

    2016-11-01

    Thrombosis and thrombo-embolism cause a range of diseases including heart attack and stroke. Closer understanding of clot and blood flow mechanics provides valuable insights on the etiology, diagnosis, and treatment of thrombotic diseases. Such mechanics are complicated, however, by the discrete and multi-scale phenomena underlying thrombosis, and the complex interactions of unsteady, pulsatile hemodynamics with a clot of arbitrary shape and microstructure. We have developed a computational technique, based on a fictitious domain based finite element method, to study these interactions. The method can resolve arbitrary clot geometries, and dynamically couple fluid flow with static or growing clot boundaries. Macroscopic thrombus-hemodynamics interactions were investigated within idealized vessel geometries representative of the common carotid artery, with realistic unsteady flow profiles as inputs. The method was also employed successfully to resolve micro-scale interactions using a model driven by in-vivo morphology data. The results provide insights into the flow structures and hemodynamic loading around an arbitrarily grown clot at arterial length-scales, as well as flow and transport within the interstices of platelet aggregates composing the clot. The work was supported by AHA Award No: 16POST27500023.

  9. Blood Clots

    Science.gov (United States)

    ... or prevent blood clots from dissolving properly. Risk factors for excessive blood clotting include Certain genetic disorders Atherosclerosis Diabetes Atrial fibrillation Overweight, obesity, and metabolic syndrome Some medicines Smoking deep vein ...

  10. Modelling of platelet-fibrin clot formation in flow with a DPD-PDE method.

    Science.gov (United States)

    Tosenberger, A; Ataullakhanov, F; Bessonov, N; Panteleev, M; Tokarev, A; Volpert, V

    2016-02-01

    The paper is devoted to mathematical modelling of clot growth in blood flow. Great complexity of the hemostatic system dictates the need of usage of the mathematical models to understand its functioning in the normal and especially in pathological situations. In this work we investigate the interaction of blood flow, platelet aggregation and plasma coagulation. We develop a hybrid DPD-PDE model where dissipative particle dynamics (DPD) is used to model plasma flow and platelets, while the regulatory network of plasma coagulation is described by a system of partial differential equations. Modelling results confirm the potency of the scenario of clot growth where at the first stage of clot formation platelets form an aggregate due to weak inter-platelet connections and then due to their activation. This enables the formation of the fibrin net in the centre of the platelet aggregate where the flow velocity is significantly reduced. The fibrin net reinforces the clot and allows its further growth. When the clot becomes sufficiently large, it stops growing due to the narrowed vessel and the increase of flow shear rate at the surface of the clot. Its outer part is detached by the flow revealing the inner part covered by fibrin. This fibrin cap does not allow new platelets to attach at the high shear rate, and the clot stops growing. Dependence of the final clot size on wall shear rate and on other parameters is studied.

  11. Blood Clots

    Science.gov (United States)

    ... and may include pain or cramping, swelling, tenderness, warmth to the touch and bluish- or red-colored ... caused the clot, and will also perform a physical examination. In an emergency situation where patients may ...

  12. DIRECT SMEAR VS CELL BLOCK (PLASMA- THROMBIN CLOT METHOD: DIAGNOSTIC VALUE IN SEROSAL CAVITIES FLUIDS CYTOLOGY

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    P MAHZOUNI

    2000-03-01

    Full Text Available Introduction. To improve testing sensitivity, most laboratories use two or more preparation methods but in our laboratories only one method is used which is "direct smear". In this study we tried to evaluate the diagnostic value of cell block as adjunct to direct smear in the cytologic investigation of serosal cavities fluids. Methods. In a clinical trial study 62 specimens of serosal cavity fluids were investigated in AL-Zahrapathology laboratory (Get. 1998 to Get. 1999. Cytologic slides from each specimens were prepared in two methods: direct smear and cell block (plasma- thrombin clot method. Smears and cell blocks were studied separately by the same cytopathologist. The diagnosis were categorized as positive, negative, suspicious or unsatisfactory. Also, the time required for studing of each slides were noted. Findings. The findings indicated that there are discrepancy between direct smear and cell block methods in the number of "suspicious" cases. Also there is significant difference between the mean time needed for studing of direct smear and cell block. Conclusion. It is recommended that the remainer of each specimen should be kept in refrigerator in order to prepare cell blocks in suspicious cases of direct smear. This method facilitates making a more definite diagnosis and reducing the number of suspicious cases.

  13. Application and validation of the lattice Boltzmann method for modelling flow-related clotting.

    Science.gov (United States)

    Harrison, S E; Smith, S M; Bernsdorf, J; Hose, D R; Lawford, P V

    2007-01-01

    The purpose of this paper is to present a simple clotting model, based on residence time and shear stress distribution, that can simulate the deposition over time of enzyme-activated milk in an in vitro system. Results for the model are compared with experiments exhibiting clot deposition in the region of a sharp-edged stenosis. The milk experiments have been shown to be a valuable analogue for the experimental representation of flow-induced blood clotting, particularly in the context of separation of hydrodynamic from biochemical factors. The facility to predict the flow-induced clotting of the blood analogue, in which the chemistry reduces to what is effectively a zeroth order reaction, gives confidence in this physics-based approach to simulation of the final part of the coagulation cascade. This type of study is a necessary precursor to the development of a complex, multi-factorial, biochemical model of the process of thrombosis. In addition to the clotting simulations, comparisons are reported between the computed flow patterns prior to clot deposition and flow visualisation studies. Excellent agreement of hydrodynamic parameters is reported for a Reynolds number of 100, and qualitative agreement is seen for the complex, disturbed flow occurring at a physiologically relevant Reynolds number of 550. The explicit, time-stepping lattice Boltzmann approach may have particular merit for the transitional flow at this higher Reynolds number.

  14. Blood Clotting and Pregnancy

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    Full Text Available ... Blood Basics Blood Disorders Anemia Bleeding Disorders Blood Cancers Blood Clots Blood Clotting and Pregnancy Clots and ... Increased maternal age Other medical illness (e.g., cancer, infection) back to top How are Blood Clots ...

  15. Blood Clotting and Pregnancy

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    Full Text Available ... Blood Basics Blood Disorders Anemia Bleeding Disorders Blood Cancers Blood Clots Blood Clotting and Pregnancy Clots and ... Increased maternal age Other medical illness (e.g., cancer, infection) back to top How are Blood Clots ...

  16. Blood Clotting and Pregnancy

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    Full Text Available ... For Patients Blood Disorders Blood Clots Blood Clotting & Pregnancy If you are pregnant, or you have just ... The risk of developing a blood clot during pregnancy is increased by the following: Previous blood clots ...

  17. Blood Clotting and Pregnancy

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    Full Text Available ... infection) back to top How are Blood Clots in Pregnant Women Treated? Typically, blood clots are treated ... history of blood clots or blood clotting disorders in your family. Remain active, with your doctor's approval. ...

  18. Blood Clotting and Pregnancy

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    Full Text Available ... Blood Basics Blood Disorders Anemia Bleeding Disorders Blood Cancers Blood Clots Clots and Travel Blood Clotting and ... Increased maternal age Other medical illness (e.g., cancer, infection) back to top How are Blood Clots ...

  19. Blood Clotting and Pregnancy

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    Full Text Available ... improve the diagnosis and treatment of acute myeloid leukemia (AML). 2018 Highlights of ASH Attend a meeting ... Blood Basics Blood Disorders Anemia Bleeding Disorders Blood Cancers Blood Clots Blood Clotting and Pregnancy Clots and ...

  20. Integration of acoustic radiation force and optical imaging for blood plasma clot stiffness measurement.

    Science.gov (United States)

    Wang, Caroline W; Perez, Matthew J; Helmke, Brian P; Viola, Francesco; Lawrence, Michael B

    2015-01-01

    Despite the life-preserving function blood clotting serves in the body, inadequate or excessive blood clot stiffness has been associated with life-threatening diseases such as stroke, hemorrhage, and heart attack. The relationship between blood clot stiffness and vascular diseases underscores the importance of quantifying the magnitude and kinetics of blood's transformation from a fluid to a viscoelastic solid. To measure blood plasma clot stiffness, we have developed a method that uses ultrasound acoustic radiation force (ARF) to induce micron-scaled displacements (1-500 μm) on microbeads suspended in blood plasma. The displacements were detected by optical microscopy and took place within a micro-liter sized clot region formed within a larger volume (2 mL sample) to minimize container surface effects. Modulation of the ultrasound generated acoustic radiation force allowed stiffness measurements to be made in blood plasma from before its gel point to the stage where it was a fully developed viscoelastic solid. A 0.5 wt % agarose hydrogel was 9.8-fold stiffer than the plasma (platelet-rich) clot at 1 h post-kaolin stimulus. The acoustic radiation force microbead method was sensitive to the presence of platelets and strength of coagulation stimulus. Platelet depletion reduced clot stiffness 6.9 fold relative to platelet rich plasma. The sensitivity of acoustic radiation force based stiffness assessment may allow for studying platelet regulation of both incipient and mature clot mechanical properties.

  1. Histotripsy Thrombolysis on Retracted Clots.

    Science.gov (United States)

    Zhang, Xi; Owens, Gabe E; Cain, Charles A; Gurm, Hitinder S; Macoskey, Jonathan; Xu, Zhen

    2016-08-01

    Retracted blood clots have been previously recognized to be more resistant to drug-based thrombolysis methods, even with ultrasound and microbubble enhancements. Microtripsy, a new histotripsy approach, has been investigated as a non-invasive, drug-free and image-guided method that uses ultrasound to break up clots with improved treatment accuracy and a lower risk of vessel damage compared with the traditional histotripsy thrombolysis approach. Unlike drug-mediated thrombolysis, which is dependent on the permeation of the thrombolytic agents into the clot, microtripsy controls acoustic cavitation to fractionate clots. We hypothesize that microtripsy thrombolysis is effective on retracted clots and that the treatment efficacy can be enhanced using strategies incorporating electronic focal steering. To test our hypothesis, retracted clots were prepared in vitro and the mechanical properties were quantitatively characterized. Microtripsy thrombolysis was applied on the retracted clots in an in vitro flow model using three different strategies: single-focus, electronically-steered multi-focus and dual-pass multi-focus. Results show that microtripsy was used to successfully generate a flow channel through the retracted clot and the flow was restored. The multi-focus and the dual-pass treatments incorporating the electronic focal steering significantly increased the recanalized flow channel size compared to the single-focus treatments. The dual-pass treatments achieved a restored flow rate up to 324 mL/min without cavitation contacting the vessel wall. The clot debris particles generated from microtripsy thrombolysis remained within the safe range. The results of this study show the potential of microtripsy thrombolysis for retracted clot recanalization with the enhancement of electronic focal steering. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  2. Sol-gel method for encapsulating molecules

    Science.gov (United States)

    Brinker, C. Jeffrey; Ashley, Carol S.; Bhatia, Rimple; Singh, Anup K.

    2002-01-01

    A method for encapsulating organic molecules, and in particular, biomolecules using sol-gel chemistry. A silica sol is prepared from an aqueous alkali metal silicate solution, such as a mixture of silicon dioxide and sodium or potassium oxide in water. The pH is adjusted to a suitably low value to stabilize the sol by minimizing the rate of siloxane condensation, thereby allowing storage stability of the sol prior to gelation. The organic molecules, generally in solution, is then added with the organic molecules being encapsulated in the sol matrix. After aging, either a thin film can be prepared or a gel can be formed with the encapsulated molecules. Depending upon the acid used, pH, and other processing conditions, the gelation time can be from one minute up to several days. In the method of the present invention, no alcohols are generated as by-products during the sol-gel and encapsulation steps. The organic molecules can be added at any desired pH value, where the pH value is generally chosen to achieve the desired reactivity of the organic molecules. The method of the present invention thereby presents a sufficiently mild encapsulation method to retain a significant portion of the activity of the biomolecules, compared with the activity of the biomolecules in free solution.

  3. Stacking gels: A method for maximising output for pulsed-field gel electrophoresis

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    Heng See

    2009-01-01

    Full Text Available Pulsed field gel electrophoresis (PFGE, the gold standard of molecular typing methods, has a major disadvantage of an unusually long electrophoretic time. From the original protocol of 6 days, it was modified to 3 days and subsequently to a single day. We describe the procedure of stacking five to six gels one on top of another in order to increase and maximize the output in a shorter time without compromising the resolution and reproducibility. All the variables that affect pulsed field gels during electrophoresis were taken into consideration. We firstly optimized the parameters to be used and secondly determined whether stacking of five to six gels had any effect on the molecular separation during electrophoresis in comparison with a single gel run. DNA preparation, restriction, electrophoresis, staining and gel documentation was carried out based on previously published methods. Gels were analysed using BioNumerics and dice coefficient and unweighted pair group methods were used to generate dendrograms based on 1.5% tolerance values. Identical band profiles and band resolution-separation were seen in the PFGE patterns with single gel and multiple stacking gels. Cluster analysis further strengthened the fact that results from stacking gels were reproducible and comparable with a single gel run. This method of stacking gels saves time and maximizes the output at the same time. The run time for a single gel was about 28 hours, but with six stacked gels the run time was 54 hours compared with 28 x 6 = 168 hours if they were run separately as single gels thus saving time of 67.86%. Beside the big factor of saving time, stacking gels save resources (electricity, reagents, water, chemicals and working time by increasing the sample throughput in a shorter time without compromising on quality of data. But optimization of working parameters is vital depending on the PFGE system used.

  4. Blood Clotting and Pregnancy

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    Full Text Available ... increased by the following: Previous blood clots A genetic predisposition to blood clots Obesity Prolonged immobility (e. ... you are interested in learning more about blood diseases and disorders, here are a few other resources ...

  5. Blood Clotting and Pregnancy

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    Full Text Available ... harming your baby. Jump To: Am I at Risk? The risk of developing a blood clot during pregnancy is ... prevent blood clots during pregnancy: Be aware of risk factors. Know your family history. Make sure your ...

  6. Blood Clotting and Pregnancy

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    Full Text Available ... pregnancy: Be aware of risk factors. Know your family history. Make sure your doctor knows about any ... blood clots or blood clotting disorders in your family. Remain active, with your doctor's approval. Be aware ...

  7. Blood Clotting and Pregnancy

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    Full Text Available ... blood clots A genetic predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) ... If you find that you are interested in learning more about blood diseases and disorders, here are ...

  8. Blood Clotting and Pregnancy

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    Full Text Available ... blood clots A genetic predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) ... pregnancy: Be aware of risk factors. Know your family history. Make sure your doctor knows about any ...

  9. Blood Clotting and Pregnancy

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    Full Text Available ... pregnancy: Be aware of risk factors. Know your family history. Make sure your doctor knows about any ... blood clots or blood clotting disorders in your family. Remain active, with your doctor's approval. Be aware ...

  10. Blood Clotting and Pregnancy

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    Full Text Available ... Blood: How I Treat A compendium of Blood articles updated to reflect the most recent scientific research View all publications For Patients Blood Basics Blood Disorders Anemia Bleeding Disorders Blood Cancers Blood Clots Blood Clotting and Pregnancy Clots and ...

  11. Blood Clotting and Pregnancy

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    Full Text Available ... prevent blood clots during pregnancy: Be aware of risk factors. Know your family history. Make sure your doctor knows about any ... blood clots or blood clotting disorders in your family. Remain active, with ... doctor about your risks and prevention. Depending on your condition, your OB- ...

  12. Blood Clotting and Pregnancy

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    Full Text Available ... blood clots A genetic predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple births Increased maternal age Other medical illness (e.g., cancer, infection) back to top How are Blood Clots ...

  13. Formulation and method for preparing gels comprising hydrous hafnium oxide

    Science.gov (United States)

    Collins, Jack L; Hunt, Rodney D; Montgomery, Frederick C

    2013-08-06

    Formulations useful for preparing hydrous hafnium oxide gels contain a metal salt including hafnium, an acid, an organic base, and a complexing agent. Methods for preparing gels containing hydrous hafnium oxide include heating a formulation to a temperature sufficient to induce gel formation, where the formulation contains a metal salt including hafnium, an acid, an organic base, and a complexing agent.

  14. Formulation and method for preparing gels comprising hydrous aluminum oxide

    Science.gov (United States)

    Collins, Jack L.

    2014-06-17

    Formulations useful for preparing hydrous aluminum oxide gels contain a metal salt including aluminum, an organic base, and a complexing agent. Methods for preparing gels containing hydrous aluminum oxide include heating a formulation to a temperature sufficient to induce gel formation, where the formulation contains a metal salt including aluminum, an organic base, and a complexing agent.

  15. Formulation and method for preparing gels comprising hydrous cerium oxide

    Science.gov (United States)

    Collins, Jack L; Chi, Anthony

    2013-05-07

    Formulations useful for preparing hydrous cerium oxide gels contain a metal salt including cerium, an organic base, and a complexing agent. Methods for preparing gels containing hydrous cerium oxide include heating a formulation to a temperature sufficient to induce gel formation, where the formulation contains a metal salt including cerium, an organic base, and a complexing agent.

  16. DIRECT SMEAR VS CELL BLOCK (PLASMA- THROMBIN CLOT) METHOD: DIAGNOSTIC VALUE IN SEROSAL CAVITIES FLUIDS CYTOLOGY

    OpenAIRE

    Mahzouni, P.; M SHARIFANI

    2000-01-01

    Introduction. To improve testing sensitivity, most laboratories use two or more preparation methods but in our laboratories only one method is used which is "direct smear". In this study we tried to evaluate the diagnostic value of cell block as adjunct to direct smear in the cytologic investigation of serosal cavities fluids. Methods. In a clinical trial study 62 specimens of serosal cavity fluids were investigated in AL-Zahrapathology laboratory (Get. 1998 to Get. 1999). Cytologic slid...

  17. A method for easily customizable gradient gel electrophoresis.

    Science.gov (United States)

    Miller, Andrew J; Roman, Brandon; Norstrom, Eric

    2016-09-15

    Gradient polyacrylamide gel electrophoresis is a powerful tool for the resolution of polypeptides by relative mobility. Here, we present a simplified method for generating polyacrylamide gradient gels for routine analysis without the need for specialized mixing equipment. The method allows for easily customizable gradients which can be optimized for specific polypeptide resolution requirements. Moreover, the method eliminates the possibility of buffer cross contamination in mixing equipment, and the time and resources saved with this method in place of traditional gradient mixing, or the purchase of pre-cast gels, are noteworthy given the frequency with which many labs use gradient gel SDS-PAGE. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. In Vivo Quantification of Clot Formation in Extracorporeal Circuits

    CERN Document Server

    David, Omid

    2012-01-01

    Clot formation is a common complication in extracorporeal circuits. In this paper we describe a novel method for clot formation analysis using image processing. We assembled a closed extracorporeal circuit and circulated blood at varying speeds. Blood filters were placed in downstream of the flow, and clotting agents were added to the circuit. Digital images of the filter were subsequently taken, and image analysis was applied to calculate the density of the clot. Our results show a significant correlation between the cumulative size of the clots, the density measure of the clot based on image analysis, and flow duration in the system.

  19. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... just had a baby, you are at greater risk of developing a blood clot. Blood clots in pregnant women tend to form in the deep veins of the legs or in the pelvic area. This condition is known as deep vein thrombosis (DVT). Pulmonary embolism (PE) is a life-threatening ...

  20. Method for preparing hydrous zirconium oxide gels and spherules

    Science.gov (United States)

    Collins, Jack L.

    2003-08-05

    Methods for preparing hydrous zirconium oxide spherules, hydrous zirconium oxide gels such as gel slabs, films, capillary and electrophoresis gels, zirconium monohydrogen phosphate spherules, hydrous zirconium oxide spherules having suspendable particles homogeneously embedded within to form a composite sorbent, zirconium monohydrogen phosphate spherules having suspendable particles of at least one different sorbent homogeneously embedded within to form a composite sorbent having a desired crystallinity, zirconium oxide spherules having suspendable particles homogeneously embedded within to form a composite, hydrous zirconium oxide fiber materials, zirconium oxide fiber materials, hydrous zirconium oxide fiber materials having suspendable particles homogeneously embedded within to form a composite, zirconium oxide fiber materials having suspendable particles homogeneously embedded within to form a composite and spherules of barium zirconate. The hydrous zirconium oxide spherules and gel forms prepared by the gel-sphere, internal gelation process are useful as inorganic ion exchangers, catalysts, getters and ceramics.

  1. Method of making ionic liquid mediated sol-gel sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Malik, Abdul; Shearrow, Anne M.

    2017-01-31

    Ionic liquid (IL)-mediated sol-gel hybrid organic-inorganic materials present enormous potential for effective use in analytical microextraction. One obstacle to materializing this prospect arises from high viscosity of ILs significantly slowing down sol-gel reactions. A method was developed which provides phosphonium-based, pyridinium-based, and imidazolium-based IL-mediated advanced sol-gel organic-inorganic hybrid materials for capillary microextraction. Scanning electron microscopy results demonstrate that ILs can serve as porogenic agents in sol-gel reactions. IL-mediated sol-gel coatings prepared with silanol-terminated polymers provided up to 28 times higher extractions compared to analogous sol-gel coatings prepared without any IL in the sol solution. This study shows that IL-generated porous morphology alone is not enough to provide effective extraction media: careful choice of the organic polymer and the precursor with close sol-gel reactivity must be made to ensure effective chemical bonding of the organic polymer to the created sol-gel material to be able to provide the desired sorbent characteristics.

  2. A New Standard-Based Polynomial Interpolation (SBPIn) method to address gel-to-gel variability for the comparison of multiple denaturing gradient gel electrophoresis profile matrices.

    Science.gov (United States)

    Valentín-Vargas, Alexis; Chorover, Jon; Maier, Raina M

    2013-02-15

    The Standard-Based Polynomial Interpolation (SBPIn) method is a new simple three-step protocol proposed to address common gel-to-gel variations for the comparison of sample profiles across multiple DGGE gels. The advantages of this method include no requirement for additional software or modification of the standard DGGE protocol.

  3. A New Standard-Based Polynomial Interpolation (SBPIn) Method to Address Gel-to-Gel Variability for the Comparison of Multiple Denaturing Gradient Gel Electrophoresis Profile Matrices

    Science.gov (United States)

    Valentín-Vargas, Alexis; Chorover, Jon; Maier, Raina M.

    2013-01-01

    The Standard-Based Polynomial Interpolation (SBPIn) method is a new simple three-step protocol proposed to address common gel-to-gel variations for the comparison of sample profiles across multiple DGGE gels. The advantages of this method include no requirement for additional software or modification of the standard DGGE protocol. PMID:23234884

  4. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple births Increased maternal age Other medical illness (e.g., cancer, infection) back to top How are Blood ...

  5. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... dangerous to your baby. Blood clots can form inside the placenta, cutting off blood flow and harming ... 0544 | Fax 202-776-0545 ASH Store ASH Job Center ASH Apps Share Your Idea Donate Research ...

  6. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... harming your baby. Jump To: Am I at Risk? The risk of developing a blood clot during ... Advances The Hematologist ASH Clinical News ASH Self-Assessment Program Hematology , ASH Education Program About Awards Membership ...

  7. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... Find a Hematologist Clinical Trials Talking with Your Doctor Patient Group Links Advocacy Toolkit Home For Patients ... factors. Know your family history. Make sure your doctor knows about any history of blood clots or ...

  8. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... education program designed to improve the diagnosis and treatment of acute myeloid leukemia (AML). 2017 ASH Meeting ... and increase research on the causes, prevention, and treatment. Blood clots are also potentially dangerous to your ...

  9. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... known as venous thromboembolism, are highly preventable (see prevention tips below). The U.S. Surgeon General has issued ... blood conditions and increase research on the causes, prevention, and treatment. Blood clots are also potentially dangerous ...

  10. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... genetic predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple births Increased maternal age Other medical illness (e.g., cancer, infection) back to top How are ...

  11. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... known as venous thromboembolism, are highly preventable (see prevention tips below). The U.S. Surgeon General has issued ... blood conditions and increase research on the causes, prevention, and treatment. Blood clots are also potentially dangerous ...

  12. Honey Bee Venom (Apis mellifera Contains Anticoagulation Factors and Increases the Blood-clotting Time

    Directory of Open Access Journals (Sweden)

    Hossein Zolfagharian

    2015-12-01

    Full Text Available Objectives: Bee venom (BV is a complex mixture of proteins and contains proteins such as phospholipase and melittin, which have an effect on blood clotting and blood clots. The mechanism of action of honey bee venom (HBV, Apis mellifera on human plasma proteins and its anti-thrombotic effect were studied. The purpose of this study was to investigate the anti-coagulation effect of BV and its effects on blood coagulation and purification. Methods: Crude venom obtained from Apis mellifera was selected. The anti-coagulation factor of the crude venom from this species was purified by using gel filtration chromatography (sephadex G-50, and the molecular weights of the anti-coagulants in this venom estimated by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE. Blood samples were obtained from 10 rabbits, and the prothrombin time (PT and the partial thromboplastin time (PTT tests were conducted. The approximate lethal dose (LD values of BV were determined. Results: Crude BV increased the blood clotting time. For BV concentrations from 1 to 4 mg/mL, clotting was not observed even at more than 300 seconds, standard deviations (SDs = ± 0.71; however, clotting was observed in the control group 13.8 s, SDs = ± 0.52. Thus, BV can be considered as containing anti-coagulation factors. Crude BV is composed 4 protein bands with molecular weights of 3, 15, 20 and 41 kilodalton (kDa, respectively. The LD50 of the crude BV was found to be 177.8 μg/mouse. Conclusion: BV contains anti-coagulation factors. The fraction extracted from the Iranian bees contains proteins that are similar to anti-coagulation proteins, such as phospholipase A2 (PLA2 and melittin, and that can increase the blood clotting times in vitro.

  13. The Contribution of Pin End-Cup Interactions to Clot Strength Assessed with Thrombelastography.

    Science.gov (United States)

    Nielsen, Vance G

    2016-01-01

    Viscoelastic methods have been developed to assess the contribution of plasma proteins and platelets to coagulation in vitro to guide clinical transfusion therapy. One of the cardinal precepts of determining clot strength is making sure that the viscoelastic technique includes complete exposure of the plastic pin in the testing chamber with the fluid analyzed so as to assure maximal interaction of the cup wall with the pin surface. However, the various contributions of the pin surface area to final clot strength have not been investigated. That is, it is not clear what is more important in the in vitro determination of clot strength, the surface area shared between the cup and pin filled with fluid or the final viscoelastic resistance of the gel matrix formed. Thus, the purpose of this investigation was to determine the clot strength when only the tip of the pin was engaged with plasma thrombus and to compare these values with clot strength values obtained when the pin was completely in plasma. After determining the minimal amount of plasma required to cover a pin tip in a thrombelastographic system (30 μL), clot strength (elastic modulus, G) was determined in plasma samples of 30 or 360 μL final volume (n = 12 per condition) after tissue factor activation. The G value with 30 μL volume was 1057 ± 601 dynes/cm (mean ± SD; 95% confidence interval, 675-1439 dynes/cm), which was (P = 0.0015) smaller than the G value associated with 360-μL sample volumes, that was 1712 ± 48 dynes/cm (confidence interval, 1681-1742 dynes/cm). In conclusion, these data demonstrate that clot strength is not determined by a simple ratio of surface area of pin and cup to volume of sample, but rather strength is importantly influenced by the viscoelastic resistance of the fluid assessed.

  14. Continuous alumina gel fibers by sol-gel method using glycolic acid, aluminum nitrate and polyvinylpyrrolidone

    Directory of Open Access Journals (Sweden)

    Hongbin Tan

    2011-09-01

    Full Text Available Continuous alumina fibers were prepared by sol-gel method. The spinning sol was obtained by mixing aluminum nitrate, glycolic acid and polyvinylpyrrolidone with a weight ratio of 10:3:1.5. Fourier transform infrared (FTIR spectra, X-ray diffraction (XRD, and scanning electron microscopy (SEM were used to characterize the properties of the gel and ceramic fibers. The fibers with a uniform diameter and smooth surface were obtained by sintering at 1473K, and its main phase was indentified as a-Al2O3.

  15. Isolation of Salmonella typhi from Standard Whole Blood Culture versus Blood-Clot Cultures

    Science.gov (United States)

    1988-12-01

    The use of 10% oxgall and bile broth medium, both supplemented with freshly prepared 100 u/ml streptokinase, for isolating Salmonella typhi by clot...significantly better rate of isolation than the clot culture methods. Keywords: Cultures biology; Clot cultures; Salmonella typhi ; Isolation of S. typhi; Whole blood culture; Blood-clot culture; Reprints.

  16. Methods for immobilizing nucleic acids on a gel substrate

    Energy Technology Data Exchange (ETDEWEB)

    Mirzabekov, A.D.; Proudnikov, D.Y.; Timofeev, E.N.; Kochetkova, S.V.; Florentiev, V.L.; Shick, V.V.

    1999-11-09

    A method for labeling oligonucleotide molecules, and for immobilizing oligonucleotide and DNA molecules is provided comprising modifying the molecules to create a chemically active group, and contacting activated fluorescent dyes to the region. A method for preparing an immobilization substrate is also provided comprising modifying a gel to contain desired functional groups which covalently interact with certain moieties of the oligonucleotide molecules. A method for immobilizing biomolecules and other molecules within a gel by copolymerization of allyl-substituted oligonucleotides, DNA and proteins with acrylamide is also provided.

  17. Measurement of Plasma Clotting Using Shear Horizontal Surface Acoustic Wave Sensor

    Science.gov (United States)

    Nagayama, Tatsuya; Kondoh, Jun; Oonishi, Tomoko; Hosokawa, Kazuya

    2013-07-01

    The monitoring of blood coagulation is important during operation. In this study, a shear horizontal surface acoustic wave (SH-SAW) sensor is applied to monitor plasma clotting. An SH-SAW sensor with a metallized surface for mechanical perturbation detection can detect plasma clotting. As plasma clotting is a gel formation reaction, the SH-SAW sensor detects viscoelastic property changes. On the other hand, an SH-SAW sensor with a free surface for electrical perturbation detection detects only the liquid mixing effect. No electrical property changes due to plasma clotting are obtained using this sensor. A planar electrochemical sensor is also used to monitor plasma clotting. In impedance spectral analysis, plasma clotting is measured. However, in the measurement of time responses, no differences between clotting and nonclotting are obtained. Therefore, the SH-SAW sensor is useful for monitoring plasma clotting.

  18. How Blood Clots

    Science.gov (United States)

    ... Japanese Espaniol Find information on medical topics, symptoms, drugs, procedures, news and more, written in everyday language. * This is ... Process How Blood Clots Resources In This Article Drugs Mentioned In This Article ... of the Blood (News) Is Binge-Watching Hazardous to Your Health? (News) ...

  19. Method for preparing hydrous iron oxide gels and spherules

    Science.gov (United States)

    Collins, Jack L.; Lauf, Robert J.; Anderson, Kimberly K.

    2003-07-29

    The present invention is directed to methods for preparing hydrous iron oxide spherules, hydrous iron oxide gels such as gel slabs, films, capillary and electrophoresis gels, iron monohydrogen phosphate spherules, hydrous iron oxide spherules having suspendable particles homogeneously embedded within to form composite sorbents and catalysts, iron monohydrogen phosphate spherules having suspendable particles of at least one different sorbent homogeneously embedded within to form a composite sorbent, iron oxide spherules having suspendable particles homogeneously embedded within to form a composite of hydrous iron oxide fiber materials, iron oxide fiber materials, hydrous iron oxide fiber materials having suspendable particles homogeneously embedded within to form a composite, iron oxide fiber materials having suspendable particles homogeneously embedded within to form a composite, dielectric spherules of barium, strontium, and lead ferrites and mixtures thereof, and composite catalytic spherules of barium or strontium ferrite embedded with oxides of Mg, Zn, Pb, Ce and mixtures thereof. These variations of hydrous iron oxide spherules and gel forms prepared by the gel-sphere, internal gelation process offer more useful forms of inorganic ion exchangers, catalysts, getters, dielectrics, and ceramics.

  20. Preventing and Treating Blood Clots

    Science.gov (United States)

    ... of blood clots. Heparin is recommended to treat DVT and PE for the first five to ten days, as well as for preventing blood clots ... risk of bleeding. For patients who develop a deep vein thrombosis, and/or a ... blood clot prevention will be included in your overall treatment plan, ...

  1. Mayenite Synthesized Using the Citrate Sol-Gel Method

    Energy Technology Data Exchange (ETDEWEB)

    Ude, Sabina N [ORNL; Rawn, Claudia J [ORNL; Meisner, Roberta A [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL); Kirkham, Melanie J [ORNL; Jones, Gregory L. [University of Tennessee, Knoxville (UTK); Payzant, E Andrew [ORNL

    2014-01-01

    A citrate sol-gel method has been used to synthesize mayenite (Ca12Al14O33). X-ray powder diffraction data show that the samples synthesized using the citrate sol-gel method contained CaAl2O4 and CaCO3 along with mayenite when fired ex-situ in air at 800 C but were single phase when fired at 900 C and above. Using high temperature x-ray diffraction, data collected in-situ in air at temperatures of 600 C and below showed only amorphous content; however, data collected at higher temperatures indicated the first phase to crystallize is CaCO3. High temperature x-ray diffraction data collected in 4% H2/96% N2 does not show the presence of CaCO3, and Ca12Al14O33 starts to form around 850 C. In comparison, x-ray powder diffraction data collected ex-situ on samples synthesized using traditional solid-state synthesis shows that single phase was not reached until samples were fired at 1350 C. DTA/TGA data collected either in a nitrogen environment or air on samples synthesized using the citrate gel method suggest the complete decomposition of metastable phases and the formation of mayenite at 900 C, although the phase evolution is very different depending on the environment. Brunauer-Emmett-Teller (BET) measurements showed a slightly higher surface area of 7.4 0.1 m2/g in the citrate gel synthesized samples compared to solid-state synthesized sample with a surface area of 1.61 0.02 m2/g. SEM images show a larger particle size for samples synthesized using the solid-state method compared to those synthesized using the citrate gel method.

  2. Mechanical suction for clot evacuation: experience with "suction bridge" for safe and effective clot removal.

    Science.gov (United States)

    Goel, Apul; Dalela, Diwakar

    2015-05-01

    To present the experience with the use of a "suction bridge" for removal of bladder clots. In all patients presenting with bladder clots, mechanical suction was done using a "suction bridge". This bridge has a luer lock that is fixed to the cystoscope sheath, and the other end is connected to suction tube. The suction pressure was started at 250 mmHg and was increased up to 400 mmHg if needed. Twenty patients with a mean age of 59.4 years were included. The etiologies of bladder clots included bladder tumor in nine, benign prostate hyperplasia (BPH) in two, BPH with bladder stone in one, hematochyluria in three, and post-transurethral prostate resection in 10. Eighteen patients presented in clot retention. The estimated clot size ranged from 50 mL to more than 1 L. The mean duration for clot removal was 15 min (range 5-60). The procedure was successful in all patients. There was no bladder injury. The limitations include the small number of recruits, the non-randomized nature of study, and no control group for comparison. Mechanical suction is another safe, fast, and effective option of clot removal from the urinary bladder. The suction bridge is useful while using this method.

  3. Blood grouping based on PCR methods and agarose gel electrophoresis.

    Science.gov (United States)

    Sell, Ana Maria; Visentainer, Jeane Eliete Laguila

    2015-01-01

    The study of erythrocyte antigens continues to be an intense field of research, particularly after the development of molecular testing methods. More than 300 specificities have been described by the International Society for Blood Transfusion as belonging to 33 blood group systems. The polymerase chain reaction (PCR) is a central tool for red blood cells (RBC) genotyping. PCR and agarose gel electrophoresis are low cost, easy, and versatile in vitro methods for amplifying defined target DNA (RBC polymorphic region). Multiplex-PCR, AS-PCR (Specific Allele Polymerase Chain Reaction), and RFLP-PCR (Restriction Fragment Length Polymorphism-Polymerase Chain Reaction) techniques are usually to identify RBC polymorphisms. Furthermore, it is an easy methodology to implement. This chapter describes the PCR methodology and agarose gel electrophoresis to identify the polymorphisms of the Kell, Duffy, Kidd, and MNS blood group systems.

  4. Alumina Coating on Carbon Fibers by Sol-Gel Method

    OpenAIRE

    2006-01-01

    Alumina precursor film was coated on carbon fibers by a sol-gel method using aluminum alkoxide solution. The optimum coating condition for the concentration of alumina alkoxide and silane coupling agent was determined to uniformly coat alumina precursor on carbon fibers. Alumina precursor converted to alumina ceramics by heating at 750℃. SEM and EPMA showed that alumina ceramics was uniformly coated on carbon fibers. The thickness of alumina layer increased with increasing coating times. The ...

  5. Cavitation damage in blood clots under HIFU

    Science.gov (United States)

    Weiss, Hope; Ahadi, Golnaz; Hoelscher, Thilo; Szeri, Andrew

    2010-11-01

    High Intensity Focused Ultrasound (HIFU) has been shown to accelerate thrombolysis, the dissolution of blood clots, in vitro and in vivo, for treatment of ischemic stroke. Cavitation in sonothrombolysis is thought to play an important role, although the mechanisms are not fully understood. The damage to a blood clot associated with bubble collapses in a HIFU field is studied. The region of damage caused by a bubble collapse on the fibrin network of the blood clot exposed to HIFU is estimated, and compared with experimental assessment of the damage. The mechanical damage to the network caused by a bubble is probed using two independent approaches, a strain based method and an energy based method. Immunoflourescent fibrin staining is used to assess the region of damage experimentally.

  6. Purification and characterization of anti-clotting protein component (ACPF-7221) from venom of Agkistrodon acutus

    Institute of Scientific and Technical Information of China (English)

    RUI Jing; HUAI Jian-guo; ZHANG Ye; CHENG Dong-yun; PAN Xue-bing

    2009-01-01

    Background Snake venom contains a number of components with different pharmacological and biological activities, especially in cancer therapy, and has increasingly become a research focus. This study was designed to isolate and purify a novel anti-clotting protein component from the venom of Agkistrodon acutus, and to explore its physico-chemical properties and biological activity.Methods The venom of Agkistrodon was isolated and purified by ion-exchange chromatography on diethylaminoethyl (DEAE)-Sepharose Fast Flow, molecular sieve filtration through Sephadex G75, SP-Sepharose Fast Flow and molecular sieve filtration through Sephadex G50. We detected the activated partial thromboplastin time (APTT) of the eluant to select the anti-clotting protein component of interest. The molecular weight was determined by sodium dodecyl sulfate-polyacrylamid gel electrphoresis (SDS-PAGE) and liquid chromatography. Its protein content was detected by bicinchoninic acid (BCA).Results SDS-PAGE vertical gel electrophoresis showed that the anticoagulant factor is a tripolymer composed of three proteins whose molecular weights are 25 KDa, 30 KDa and 50 KDa. The factor contains about 65% percent protein.Conclusions A novel anti-clotting protein component was purified by ion-exchange chromatography and molecular sieve filtration from the venom of Agkistrodon acutus and was found to be composed of three kinds of proteins.

  7. Magnetization of microorganism cells by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    CHEN Bo; ZHAN TianZhuo; LIAN ZhiYang; ZHANG DeYuan

    2008-01-01

    Microorganism cells could be used as templates during fabrication of magnetic or conductive microstructures in different standard shapes.In this paper,feasibility of magnetizing microorganism cells by sol-gel method,which is to coat cells of Spirulina (a type of natural micro-helical microorganism) with the ferrite (a kind of magnetic material),was discussed and investigated.Then the cell form,compo-nents and the phase structure were observed and analyzed using various tools including optical microscopy,scanning electron microscopy (SEM),energy dis-persive X-ray detector (EDX),transmission electron microscopy (TEM),and X-ray diffraction analysis (XRD).Results showed that spirulina cells could be coated with ferrite after the sol-gel process,with the shape of natural helixes well kept,that the components of different sampling points on the surface layer were consistent and the thickness of layer was uniform,and that the type of the surface ferrite layer formed was cubic Fe304.It was also observed that there were nano-parUcles yielded in the cells and certain deposit on the walls between cells.The kinetics of the cell magnetization technology by sol-gel was also discussed.

  8. Magnetization of microorganism cells by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Microorganism cells could be used as templates during fabrication of magnetic or conductive microstructures in different standard shapes. In this paper, feasibility of magnetizing microorganism cells by sol-gel method, which is to coat cells of Spirulina (a type of natural micro-helical microorganism) with the ferrite (a kind of magnetic material), was discussed and investigated. Then the cell form, components and the phase structure were observed and analyzed using various tools including optical microscopy, scanning electron microscopy (SEM), energy dispersive X-ray detector (EDX), transmission electron microscopy (TEM), and X-ray diffraction analysis (XRD). Results showed that spirulina cells could be coated with ferrite after the sol-gel process, with the shape of natural helixes well kept, that the components of different sampling points on the surface layer were consistent and the thickness of layer was uniform, and that the type of the surface ferrite layer formed was cubic Fe3O4. It was also observed that there were nano-particles yielded in the cells and certain deposit on the walls between cells. The kinetics of the cell magnetization technology by sol-gel was also discussed.

  9. Establishment of a Rapid Method for Extracting Human Genomic DNA from Peripheral Clotted Blood%一种快速、经济提取外周凝血基因组DNA方法的建立

    Institute of Scientific and Technical Information of China (English)

    许丽娟; 马骁; 王洋阳; 王静; 潘晴; 刘梅

    2011-01-01

    Objective: To establish a rapid, economical method for extracting genotnic DNA from peripheral clotted blood. Methods: Explore a optimum homogenate condition, homogenate the clotted blood, extracting the genomic DNA by KI method. Use agarose gel electrophoresis, single PCR and multiplex PCR detect the genomic DNA extraction yield and quality. And compared with the traditional extraction methods, Proteinase K digestion method and KI method which extract DNA from anti-coagulated blood. Results: The optimum homogenate condition is 39000 rmp and 15 seconds. The genomic DNA was extracted under this condition has good integrity. There is no significant difference of purity and yield between this method and Proteinase K digestion and KI method. Single PCR and multiplex PCR also obtained good amplification results. Conclusion: Compared with traditional extraction methods (Proteinase K digestion method),this method can save time and cost, which can extract DNA rapidly,economical and effectively,and can be used in clinical and research analysis, and can solve the blood genomic DNA sources of some of the research institutions.%目的:建立一种经济、快速且高质量提取人体外周凝血DNA的方法.方法:摸索最佳的匀浆条件,对外周凝血块进行匀浆,采用KI法对匀浆液进行基因组DNA的提取,通过凝胶电泳、单重PCR和多重PCR检测凝血基因组DNA的提取产量和质量,并分别与常规的凝血基因组DNA提取方法,即蛋白酶K消化法,以及提取抗凝血基因组DNA的KI法进行比较分析.结果:最佳的匀浆条件为:39000 rmp,15秒.在此条件下提取的基因组DNA完整性好,纯度和产量与蛋白酶K消化法提取凝血DNA和KI法提取抗凝血DNA的结果相比,没有统计学差异.单重PCR和多重PCR也获得了理想的扩增结果.结论:与常规的外周凝血提取方法相比(蛋白酶K消化法),本方法节省了时间和成本,能快速、经济、有效地提取外周凝血基因组DNA,可

  10. Dosimetry using radiosensitive gels in radiotherapy: significance and methods; Dosimetrie par gels radiosensibles en radiotherapie. Interet et methodes

    Energy Technology Data Exchange (ETDEWEB)

    Gibon, D. [Dept. de Radiotherapie, Centre Oscar Lambret, Lille Cedex (France); Bourel, P. [Lab. de Biophysique, Inst. de Technologie Medicale, Centre Hospitalier Universitaire, Lille (France); Castelain, B. [Dept. de Radiotherapie, Centre Oscar Lambret, Lille Cedex (France); Marchandise, X.; Rousseau, J. [Lab. de Biophysique, Inst. de Technologie Medicale, Centre Hospitalier Universitaire, Lille (France)

    2001-02-01

    The goal of conformal radiotherapy is to concentrate the dose in a well-defined volume by avoiding the neighbouring healthy structures. This technique requires powerful treatment planning software and a rigorous control of estimated dosimetry. The usual dosimetric tools are not adapted to visualize and validate complex 3D treatment. Dosimetry by radiosensitive gel permits visualization and measurement of the three-dimensional dose distribution. The objective of this work is to report on current work in this field and, based on our results and our experience, to draw prospects for an optimal use of this technique. Further developments will relate to the realization of new radiosensitive gels satisfying, as well as possible, cost requirements, easy realization and use, magnetic resonance imagery (MRI) sensitivity, tissue equivalence, and stability. Other developments focus on scanning methods, especially in MRI to measure T1 and T2. (author)

  11. A silica gel based method for extracting insect surface hydrocarbons.

    Science.gov (United States)

    Choe, Dong-Hwan; Ramírez, Santiago R; Tsutsui, Neil D

    2012-02-01

    Here, we describe a novel method for the extraction of insect cuticular hydrocarbons using silica gel, herein referred to as "silica-rubbing". This method permits the selective sampling of external hydrocarbons from insect cuticle surfaces for subsequent analysis using gas chromatography-mass spectrometry (GC-MS). The cuticular hydrocarbons are first adsorbed to silica gel particles by rubbing the cuticle of insect specimens with the materials, and then are subsequently eluted using organic solvents. We compared the cuticular hydrocarbon profiles that resulted from extractions using silica-rubbing and solvent-soaking methods in four ant and one bee species: Linepithema humile, Azteca instabilis, Camponotus floridanus, Pogonomyrmex barbatus (Hymenoptera: Formicidae), and Euglossa dilemma (Hymenoptera: Apidae). We also compared the hydrocarbon profiles of Euglossa dilemma obtained via silica-rubbing and solid phase microextraction (SPME). Comparison of hydrocarbon profiles obtained by different extraction methods indicates that silica rubbing selectively extracts the hydrocarbons that are present on the surface of the cuticular wax layer, without extracting hydrocarbons from internal glands and tissues. Due to its surface specificity, efficiency, and low cost, this new method may be useful for studying the biology of insect cuticular hydrocarbons.

  12. Kaolin clotting time.

    Science.gov (United States)

    Radhakrishnan, Kottayam

    2013-01-01

    The kaolin clotting time (KCT) is a sensitive test used in the laboratory detection of lupus anticoagulants (LA) (Derksen and de Groot, Thromb Res 114:521-526, 2004). It is essentially an activated partial thromboplastin time (APTT) test with no added phospholipid. Kaolin acts as the activator in the KCT. In the absence of additional phospholipid reagent, the quality of the test sample is extremely important since the generation of thrombin completely depends on the presence of residual cell membranes and plasma lipids (Derksen and de Groot, Thromb Res 114:521-526, 2004). Since the test contains no exogenous phospholipid, a confirmatory test using excess phospholipid is required to confirm the presence of lupus anticoagulant in the sample (Court, Br J Biomed Sci 54:287-298, 1997).

  13. Identification of fibrin clot-bound plasma proteins.

    Directory of Open Access Journals (Sweden)

    Simone Talens

    Full Text Available Several proteins are known to bind to a fibrin network and to change clot properties or function. In this study we aimed to get an overview of fibrin clot-bound plasma proteins. A plasma clot was formed by adding thrombin, CaCl(2 and aprotinin to citrated platelet-poor plasma and unbound proteins were washed away with Tris-buffered saline. Non-covalently bound proteins were extracted, separated with 2D gel electrophoresis and visualized with Sypro Ruby. Excised protein spots were analyzed with mass spectrometry. The identity of the proteins was verified by checking the mass of the protein, and, if necessary, by Western blot analysis. Next to established fibrin-binding proteins we identified several novel fibrin clot-bound plasma proteins, including α(2-macroglobulin, carboxypeptidase N, α(1-antitrypsin, haptoglobin, serum amyloid P, and the apolipoproteins A-I, E, J, and A-IV. The latter six proteins are associated with high-density lipoprotein particles. In addition we showed that high-density lipoprotein associated proteins were also present in fibrinogen preparations purified from plasma. Most plasma proteins in a fibrin clot can be classified into three groups according to either blood coagulation, protease inhibition or high-density lipoprotein metabolism. The presence of high-density lipoprotein in clots might point to a role in hemostasis.

  14. Hemostatic, milk clotting and blood stain removal potential of cysteine proteases from Calotropis gigantea (L. R. Br. Latex

    Directory of Open Access Journals (Sweden)

    Omana Sukumaran Bindhu

    2014-01-01

    Full Text Available Introduction: Plant latex is a natural source of biologically active compounds and several hydrolytic enzymes responsible for their diverse health benefits. Recent past has witnessed substantial progress in understanding their supplementary industrial and pharmaceutical utility. Calotropis gigantea is one of the important latex producing plants belonging to asclepediaceae family with wide ethnopharmacological applications and is rich in proteolytic enzymes. Present study investigates hemostatic, milk clotting and blood stain removal potential of C. gigantea latex proteases. Materials and Methods: The protease activity of crude enzyme (CE, obtained by centrifugation followed by ammonium sulphate precipitation and dialysis, was assayed using casein as the substrate. Effect of pH, temperature and specific inhibitors on protease activity was determined. Native PAGE and in gel protease activity of CE was performed. Hemostatic (Fibrinogen polymerization, fibrinogen agarose plate and blood clot lysis assays, milk clotting and blood stain removal efficacies of CE were determined. Results: CE exhibited high caseinolytic activity. Enzyme activity was optimum at 37-50ºC and pH 8.0. Fibrinogen polymerization assay showed concentration dependent increase in turbidity indicating thrombin like activity which was further confirmed by fibrinogen agarose plate assays. Clot lysis assay indicated 92.41% thrombolysis by CE in 90 min. CE also revealed significantly high ratio of milk clotting to protease activity (Milk Clotting Index, MCI = 827.59 ± 1.52. Complete destaining of blood stained fabric was observed when incubated with 1% detergent incorporated with 0.1mg/ml CE. The study highlights and validates the compound application potential of latex cysteine proteases from C. gigantea.

  15. Nanostructured Yb:GGG polycrystalline powders via gel combustion method

    Institute of Scientific and Technical Information of China (English)

    HUANG Dexin; ZHANG Xuejian; LIU Jinghe; ZHANG Dan

    2009-01-01

    Gadolinium gallium garnet (GGG) nanopowders doped with ytterbium ions (Yb:GGG) were synthesized with citric acid as a fuel via gel combustion method. The optimized conditions for preparing Yb3+:Gd3Ga5O12 nanopowders were discussed. The heat behavior, struc-ture and morphology of powders were analyzed with thermal analysis (TG-DTA), X-ray diffraction (XRD), infrared spectra (IR) and trans-mission electron microscope (TEM). TG-DTA analysis revealed that the weight loss of the precursor occured below 800 ℃ and its crystalli-zation temperature was 830.6 ℃. XRD and IR analysis showed that the precursor converted directly into pure GGG at a relatively lower tem-perature (900 ℃) without any other intermediate phase. The lattice constant was 1.2377 calculated by extrapolation method. TEM results in-dicated that the spherical powders showed good dispersity and had a relatively narrow size distribution with average particle size of approxi-mately 40-50 nm, which was favorable for good sinterability of Yb:GCG laser ceramic.

  16. The structure of alkali silicate gel by total scattering methods

    KAUST Repository

    Benmore, C.J.

    2010-06-01

    The structure of the alkali silicate gel (ASR) collected from the galleries of Furnas Dam in Brazil was determined by a pair distribution function (PDF) analysis of high energy X-ray diffraction data. Since this method is relatively new to concrete structure analysis a detailed introduction on the PDF method is given for glassy SiO2. The bulk amorphous structure of the dam material is confirmed as no Bragg peaks are observed in the scattered intensity. The real space results show that the local structure of the amorphous material is similar to kanemite (KHSi2O5:3H2O) however the long range layer structure of the crystal is broken up in the amorphous state, so that ordering only persists of the length scale of a few polyhedra. The silicate layer structure is a much more disordered than predicted by molecular dynamics models. The X-ray results are consistent with the molecular dynamics model of Kirkpatrick et al. (2005) [1] which predicts that most of the water resides in pores within the amorphous network rather than in layers. The total scattering data provide a rigorous basis against which other models may also be tested. © 2010.

  17. Identification of Quantitative Trait Loci for Fibrin Clot Phenotypes. The EuroCLOT Study

    DEFF Research Database (Denmark)

    Williams, Frances M K; Carter, Angela M; Kato, Bernet;

    2009-01-01

    associated with fibrin phenotypes. METHODS AND RESULTS: 447 dizygotic (DZ) and 460 monozygotic (MZ) pairs of healthy UK white female twins and 199 DZ twin pairs from Denmark were studied. D-dimer, an indicator of fibrin turnover, was measured by ELISA and measures of clot formation, morphology, and lysis...

  18. /dopamine films prepared by sol-gel method

    Science.gov (United States)

    Valverde-Aguilar, G.; Prado-Prone, G.; Vergara-Aragón, P.; Garcia-Macedo, J.; Santiago, Patricia; Rendón, Luis

    2014-09-01

    Dopamine was encapsulated into nanoporous amorphous TiO2 matrix by sol-gel method under atmospheric conditions. A second sample was obtained by the addition of the crown-ether 15C5 in this previous sample. Thin films were spin-coated on glass wafers. No heat treatment was employed in both films. All films were characterized using infrared spectroscopy, high resolution transmission electronic microscopy, X-ray diffraction, optical absorption and scanning electronic microscopy. Despite the films prepared with 15C5 were no calcined, a partial crystallization was identified. Anatase and rutile nanoparticles with sizes of 4-5 nm were obtained. Photoconductivity technique was used to determine the charge transport mechanism on these films. Experimental data were fitted with straight lines at darkness and under illumination wavelengths at 320, 400, and 515 nm. It indicates an ohmic behavior. Photovoltaic and photoconductivity parameters were determined from the current density vs. the applied-electrical-field results. Amorphous film has bigger photovoltaic and photoconductive parameters than the partially crystalline film. Results observed in the present investigation prove that the nanoporous TiO2 matrix can protect the dopamine inhibiting its chemical instability. This fact modifies the optical, physical and electrical properties of the film, and is intensified when 15C5 is added.

  19. An apparatus for measuring the tensile strength of blood clots.

    Science.gov (United States)

    MACFARLANE, R G; TOMLINSON, A H

    1961-05-01

    An apparatus is described which uses the principle of the ballistic pendulum to measure the tensile strength of blood clots formed in special cuvettes. The method appears to have a reproducibility which would allow a study to be made of the factors influencing clot strength. A brief survey of the findings with normal blood and with blood from cases of thrombosis and haemophilia shows significant differences between the mean values for each group.

  20. Gel stretch method: a new method to measure constitutive properties of cardiac muscle cells

    Science.gov (United States)

    Zile, M. R.; Cowles, M. K.; Buckley, J. M.; Richardson, K.; Cowles, B. A.; Baicu, C. F.; Cooper G, I. V.; Gharpuray, V.

    1998-01-01

    Diastolic dysfunction is an important cause of congestive heart failure; however, the basic mechanisms causing diastolic congestive heart failure are not fully understood, especially the role of the cardiac muscle cell, or cardiocyte, in this process. Before the role of the cardiocyte in this pathophysiology can be defined, methods for measuring cardiocyte constitutive properties must be developed and validated. Thus this study was designed to evaluate a new method to characterize cardiocyte constitutive properties, the gel stretch method. Cardiocytes were isolated enzymatically from normal feline hearts and embedded in a 2% agarose gel containing HEPES-Krebs buffer and laminin. This gel was cast in a shape that allowed it to be placed in a stretching device. The ends of the gel were held between a movable roller and fixed plates that acted as mandibles. Distance between the right and left mandibles was increased using a stepper motor system. The force applied to the gel was measured by a force transducer. The resultant cardiocyte strain was determined by imaging the cells with a microscope, capturing the images with a CCD camera, and measuring cardiocyte and sarcomere length changes. Cardiocyte stress was characterized with a finite-element method. These measurements of cardiocyte stress and strain were used to determine cardiocyte stiffness. Two variables affecting cardiocyte stiffness were measured, the passive elastic spring and viscous damping. The passive spring was assessed by increasing the force on the gel at 1 g/min, modeling the resultant stress vs. strain relationship as an exponential [sigma = A/k(ekepsilon - 1)]. In normal cardiocytes, A = 23.0 kN/m2 and k = 16. Viscous damping was assessed by examining the loop area between the stress vs. strain relationship during 1 g/min increases and decreases in force. Normal cardiocytes had a finite loop area = 1.39 kN/m2, indicating the presence of viscous damping. Thus the gel stretch method provided accurate

  1. Preparation of silica by sol-gel method using formamide

    Directory of Open Access Journals (Sweden)

    R.F.S. Lenza

    2001-07-01

    Full Text Available In this work we obtained microporous and mesoporous silica gels by sol-gel processing. Tetraethylortosilicate (TEOS was used as precursor. Nitric acid and hydrofluoric acid were used as catalysts. In order to study the affect of formamide as drying additive, we used a molar ratio alkoxide/formamide of 1/1. The performance of formamide in obtaining crack-free gels was evaluated through monolithicity measurements. The structural evolution occurring in the interconnected network of the gels during thermal treatment was monitored by Fourier transform infrared spectroscopy (FTIR, shrinkage and density measurements and nitrogen gas sorption. We noted that in the presence of formamide, the Si-O-Si bonds are stronger and belong to a more cross-linked structure. The samples obtained in the presence of formamide have larger pore volume and its pore structure is in the range of mesoporosity. The samples obtained without additive are microporous. Formamide allowed the preparation of crack-free silica gels stabilized at high temperatures.

  2. A Quick, Cost-Free Method of Purification of DNA Fragments from Agarose Gel

    Directory of Open Access Journals (Sweden)

    Yuan Sun, Kannappan Sriramajayam, Dianzhong Luo, D. Joshua Liao

    2012-01-01

    Full Text Available In this short communication we report a quick, cost-free method of purification of DNA fragments from agarose gel. Unlike those procedures that involve commercial kits, this method uses glass wool or absorbent cotton to filter agarose gel during a quick spinning-down of DNA, thus significantly simplifying the routine practice of many molecular biologists and decreasing the cost.

  3. Preventing Blood Clots After Orthopaedic Surgery

    Medline Plus

    Full Text Available ... blood clots during the first several weeks of recovery from surgery. Warning Signs of Blood Clots Pain ... herein. This information is provided as an educational service and is not intended to serve as medical ...

  4. Preventing Blood Clots After Orthopaedic Surgery

    Medline Plus

    Full Text Available ... Clots After Orthopaedic Surgery One of the major risks facing patients who undergo surgery is a complication ... on the legs and hip are especially at risk. A pulmonary embolism is a blood clot that ...

  5. Formulation of mefenamic acid loaded transfersomal gel by thin film hydration technique and hand shaking method

    Directory of Open Access Journals (Sweden)

    Krishna Sailaja

    2017-04-01

    Full Text Available Objective(s: The aim of present study is to formulate mefenamic acid transdermal gel based on vesicular drug delivery approaches.Materials and Methods: For the preparation of mefenamic acid transdermal gel, transfersomes were selected as colloidal carriers. Transfersomes were prepared by hand shaking and thin film hydration techniques. The obtained transfersomes were characterized for vesicular diameter, zeta potential, drug content, entrapment efficiency and in vitro diffusion studies.Results: Among Different formulations of transfersomes, T10(prepared by thin film hydration and containing soya lecithin: span60 ratio 1:2 was considered as the best formulation because of its mean vesicular diameter of 369 nm, zeta potential of -14 mV, drug content of 99.6%, entrapment efficiency of 84.4%, and sustained drug release of 93.3% after 12 h.T10 formulation was incorporated into gel. Comparative study was made among plain gel, and transfersomal gel. Among these two gels, transfersomal gel considered as best because of its highest drug content (91%, spreadability (43.5 g.cm/sec, pH (6.9 and sustained drug release profile for 12 h.Conclusion: By comparing  hand shaking and thin film hydration techniques, it was found thin film hydration technique produced better results and transfersomal gel was indicated better results than plain gel.

  6. Characterization and comparison of PZT powder synthesis by solid state and sol gel methods

    Directory of Open Access Journals (Sweden)

    E Pakizeh

    2012-09-01

    Full Text Available   This paper describes the synthesis of Pb(Zr0.95Ti0.05O3 powder by sol gel and solid state methods. PZT powders were fabricated by solid-state reaction process using metal oxides and in sol gel method salts and organic compounds were employed. The powders were calcined at 700 and 950 oC in sol gel and solid state methods, respectively. The synthesized powders were analyzed by FTIR and XRD. The average crystal grain size of PZT powders determined by X-ray diffraction method using the Scherrer equation, and in sol gel and solid state methods measured 42 and 330 nm, respectively. The optical constants of powders were evaluated and compaed using FTIR transmittance spectroscopy and Kramers-Kronig analysis.

  7. Preparation of oxide glasses from metal alkoxides by sol-gel method

    Science.gov (United States)

    Kamiya, K.; Yoko, T.; Sakka, S.

    1987-01-01

    An investigation is carried out on the types of siloxane polymers produced in the course of the hydrolysis of silicon tetraethoxide, as well as the preparation of oxide glasses from metal alkoxides by the sol-gel method.

  8. [A study on the formation of apatite crystallized with gel method].

    Science.gov (United States)

    Endo, T; Amano, N; Yoshida, M; Murakami, H; Kosuge, N; Ohmi, Y; Kameda, A

    1989-10-01

    About apatite produced with a silicahydro gel method using calcium nitrate (group I) or calcium chloride (group II) and a gelatin gel method by use of calcium nitrate (group III) or calcium chloride (group IV), the formative volume as well as the formative condition of a periodic-layered precipitate (Liesegang ring), the pH measurement, calculation of Ca/P ratio, an estimation of the chlorine ion, morphological observation with a scanning electron microscope, qualitative analyses by X-ray diffraction (identification, crystallite size, lattice imperfections, lattice constants) and the composition analysis by infrared absorption spectroscopy were carried out to elucidate the formation of apatite using the gel method. The result showed that there were no distinct differences between group I-II and group III-IV, and it is suggested that it is possible to form satisfact fluorapatite with a gel method using calcium chloride as well as calcium nitrate.

  9. Nanostructured Energetic Materials with Sol-Gel Methods

    Energy Technology Data Exchange (ETDEWEB)

    Gash, A; Satcher, J; Simpson, R; Clapsaddle, B

    2003-11-25

    The utilization of sol-gel chemical methodology to prepare nanostructured energetic materials as well as the concepts of nanoenergetics is described. The preparation and characterization of two totally different compositions is detailed. In one example, nanostructured aerogel and xerogel composites of sol-gel iron (III) oxide and ultra fine grained aluminum (UFG Al) are prepared, characterized, and compared to a conventional micron-sized Fe{sub 2}O{sub 3}/Al thermite. The exquisite degree of mixing and intimate nanostructuring of this material is illustrated using transmission and scanning electron microscopies (TEM and SEM). The nanocomposite material has markedly different energy release (burn rate) and thermal properties compared to the conventional composite, results of which will be discussed. Small-scale safety characterization was performed aerogels and xerogels of the nanostructured thermite. The second nanostructured energetic material consists of a nanostructured hydrocarbon resin fuel network with fine ammonium perchlorate (NH{sub 4}ClO{sub 4}) oxidizer present.

  10. Preliminary evaluation of a gel tube agglutination major cross-match method in dogs.

    Science.gov (United States)

    Villarnovo, Dania; Burton, Shelley A; Horney, Barbara S; MacKenzie, Allan L; Vanderstichel, Raphaël

    2016-09-01

    A major cross-match gel tube test is available for use in dogs yet has not been clinically evaluated. This study compared cross-match results obtained using the gel tube and the standard tube methods for canine samples. Study 1 included 107 canine sample donor-recipient pairings cross-match tested with the RapidVet-H method gel tube test and compared results with the standard tube method. Additionally, 120 pairings using pooled sera containing anti-canine erythrocyte antibody at various concentrations were tested with leftover blood from a hospital population to assess sensitivity and specificity of the gel tube method in comparison with the standard method. The gel tube method had a good relative specificity of 96.1% in detecting lack of agglutination (compatibility) compared to the standard tube method. Agreement between the 2 methods was moderate. Nine of 107 pairings showed agglutination/incompatibility on either test, too few to allow reliable calculation of relative sensitivity. Fifty percent of the gel tube method results were difficult to interpret due to sample spreading in the reaction and/or negative control tubes. The RapidVet-H method agreed with the standard cross-match method on compatible samples, but detected incompatibility in some sample pairs that were compatible with the standard method. Evaluation using larger numbers of incompatible pairings is needed to assess diagnostic utility. The gel tube method results were difficult to categorize due to sample spreading. Weak agglutination reactions or other factors such as centrifuge model may be responsible. © 2016 American Society for Veterinary Clinical Pathology.

  11. A new device for measurement of fibrin clot lysis: application to the Euglobulin Clot Lysis Time

    Directory of Open Access Journals (Sweden)

    Brohée D

    2002-05-01

    Full Text Available Abstract Background Determination of clot lysis times on whole blood, diluted whole blood, plasma or plasma fraction has been used for many years to assess the overall activity of the fibrinolytic system. We designed a completely computerised semi-automatic 8-channel device for measurement and determination of fibrin clot lysis. The lysis time is evaluated by a mathematical analysis of the lysis curve and the results are expressed in minute (range: 5 to 9999. We have used this new device for Euglobulin Clot Lysis Time (ECLT determination, which is the most common test used in laboratories to estimate plasma fibrinolytic capacity. Results The correlation between ECLT and manual method is very tight : R = 0,99; p -6. The efficiency scores of the method are Conclusions The routine use of this new device could be useful in various situations such as assessment in atherosclerosis and arteriosclerosis associated diseases, coagulation survey of liver transplantations, cardiovascular surgery or pharmacological research. It has already provided highly promising results in preliminary studies on the relation between fibrinolysis and cardiovascular risk factors.

  12. A new device for measurement of fibrin clot lysis: application to the Euglobulin Clot Lysis Time

    Science.gov (United States)

    Boudjeltia, K Zouaoui; Cauchie, Ph; Remacle, Cl; Guillaume, M; Brohée, D; Hubert, JL; Vanhaeverbeek, M

    2002-01-01

    Background Determination of clot lysis times on whole blood, diluted whole blood, plasma or plasma fraction has been used for many years to assess the overall activity of the fibrinolytic system. We designed a completely computerised semi-automatic 8-channel device for measurement and determination of fibrin clot lysis. The lysis time is evaluated by a mathematical analysis of the lysis curve and the results are expressed in minute (range: 5 to 9999). We have used this new device for Euglobulin Clot Lysis Time (ECLT) determination, which is the most common test used in laboratories to estimate plasma fibrinolytic capacity. Results The correlation between ECLT and manual method is very tight : R = 0,99; p < 10-6. The efficiency scores of the method are <4% in intra-assay and <7% in inter-assay. It allows to achieve the tests on hyperlipaemic samples. This new device has been easily integrated in laboratory routine and allows to achieve several ECLT every day without disturbance of laboratory workflow. Conclusions The routine use of this new device could be useful in various situations such as assessment in atherosclerosis and arteriosclerosis associated diseases, coagulation survey of liver transplantations, cardiovascular surgery or pharmacological research. It has already provided highly promising results in preliminary studies on the relation between fibrinolysis and cardiovascular risk factors. PMID:11985782

  13. Thermal Blood Clot Formation and use in Microfluidic Device Valving Applications

    Science.gov (United States)

    Tai, Yu-Chong (Inventor); Shi, Wendian (Inventor); Guo, Luke (Inventor)

    2014-01-01

    The present invention provides a method of forming a blood-clot microvalve by heating blood in a capillary tube of a microfluidic device. Also described are methods of modulating liquid flow in a capillary tube by forming and removing a blood-clot microvalve.

  14. Identification of quantitative trait loci for fibrin clot phenotypes: The EuroCLOT study

    Science.gov (United States)

    Williams, Frances MK; Carter, Angela M; Kato, Bernet; Falchi, Mario; Bathum, Lise; Surdulescu, Gabriela; Kyvik, Kirsten Ohm; Palotie, Aarno; Spector, Tim D; Grant, Peter J

    2012-01-01

    Objectives Fibrin makes up the structural basis of an occlusive arterial thrombus and variability in fibrin phenotype relates to cardiovascular risk. The aims of the current study from the EU consortium EuroCLOT were to 1) determine the heritability of fibrin phenotypes and 2) identify QTLs associated with fibrin phenotypes. Methods 447 dizygotic (DZ) and 460 monozygotic (MZ) pairs of healthy UK Caucasian female twins and 199 DZ twin pairs from Denmark were studied. D-dimer, an indicator of fibrin turnover, was measured by ELISA and measures of clot formation, morphology and lysis were determined by turbidimetric assays. Heritability estimates and genome-wide linkage analysis were performed. Results Estimates of heritability for d-dimer and turbidometric variables were in the range 17 - 46%, with highest levels for maximal absorbance which provides an estimate of clot density. Genome-wide linkage analysis revealed 6 significant regions with LOD>3 on 5 chromosomes (5, 6, 9, 16 and 17). Conclusions The results indicate a significant genetic contribution to variability in fibrin phenotypes and highlight regions in the human genome which warrant further investigation in relation to ischaemic cardiovascular disorders and their therapy. PMID:19150881

  15. Microchannel gel electrophoretic separation systems and methods for preparing and using

    Science.gov (United States)

    Herr, Amy; Singh, Anup K; Throckmorton, Daniel J

    2013-09-03

    A micro-analytical platform for performing electrophoresis-based immunoassays was developed by integrating photopolymerized cross-linked polyacrylamide gels within a microfluidic device. The microfluidic immunoassays are performed by gel electrophoretic separation and quantifying analyte concentration based upon conventional polyacrylamide gel electrophoresis (PAGE). To retain biological activity of proteins and maintain intact immune complexes, native PAGE conditions were employed. Both direct (non-competitive) and competitive immunoassay formats are demonstrated in microchips for detecting toxins and biomarkers (cytokines, c-reactive protein) in bodily fluids (serum, saliva, oral fluids). Further, a description of gradient gels fabrication is included, in an effort to describe methods we have developed for further optimization of on-chip PAGE immunoassays. The described chip-based PAGE immunoassay method enables immunoassays that are fast (minutes) and require very small amounts of sample (less than a few microliters). Use of microfabricated chips as a platform enables integration, parallel assays, automation and development of portable devices.

  16. Microchannel gel electrophoretic separation systems and methods for preparing and using

    Energy Technology Data Exchange (ETDEWEB)

    Herr, Amy E; Singh, Anup K; Throckmorton, Daniel J

    2015-02-24

    A micro-analytical platform for performing electrophoresis-based immunoassays was developed by integrating photopolymerized cross-linked polyacrylamide gels within a microfluidic device. The microfluidic immunoassays are performed by gel electrophoretic separation and quantifying analyte concentration based upon conventional polyacrylamide gel electrophoresis (PAGE). To retain biological activity of proteins and maintain intact immune complexes, native PAGE conditions were employed. Both direct (non-competitive) and competitive immunoassay formats are demonstrated in microchips for detecting toxins and biomarkers (cytokines, c-reactive protein) in bodily fluids (serum, saliva, oral fluids). Further, a description of gradient gels fabrication is included, in an effort to describe methods we have developed for further optimization of on-chip PAGE immunoassays. The described chip-based PAGE immunoassay method enables immunoassays that are fast (minutes) and require very small amounts of sample (less than a few microliters). Use of microfabricated chips as a platform enables integration, parallel assays, automation and development of portable devices.

  17. Microchannel gel electrophoretic separation systems and methods for preparing and using

    Energy Technology Data Exchange (ETDEWEB)

    Herr, Amy; Singh, Anup K; Throckmorton, Daniel J

    2013-09-03

    A micro-analytical platform for performing electrophoresis-based immunoassays was developed by integrating photopolymerized cross-linked polyacrylamide gels within a microfluidic device. The microfluidic immunoassays are performed by gel electrophoretic separation and quantifying analyte concentration based upon conventional polyacrylamide gel electrophoresis (PAGE). To retain biological activity of proteins and maintain intact immune complexes, native PAGE conditions were employed. Both direct (non-competitive) and competitive immunoassay formats are demonstrated in microchips for detecting toxins and biomarkers (cytokines, c-reactive protein) in bodily fluids (serum, saliva, oral fluids). Further, a description of gradient gels fabrication is included, in an effort to describe methods we have developed for further optimization of on-chip PAGE immunoassays. The described chip-based PAGE immunoassay method enables immunoassays that are fast (minutes) and require very small amounts of sample (less than a few microliters). Use of microfabricated chips as a platform enables integration, parallel assays, automation and development of portable devices.

  18. Dye-Sensitized Solar Cells with Optimal Gel Electrolyte Using the Taguchi Design Method

    OpenAIRE

    Jenn-Kai Tsai; Wen Dung Hsu; Tian-Chiuan Wu; Jia-Song Zhou; Ji-Lin Li; Jian-Hao Liao; Teen-Hang Meen

    2013-01-01

    The Taguchi method was adopted to determine the optimal gel electrolyte used in dye-sensitized solar cells (DSSCs). Since electrolyte is a very important factor in fabrication of high performance and long-term stability DSSCs, to find the optimal composition of gel electrolyte is desired. In this paper, the common ingredients used in the liquid electrolyte were chosen. The ingredients then mixed with cheap ionic liquids and poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP) were added...

  19. Fluid Mechanics of Blood Clot Formation.

    Science.gov (United States)

    Fogelson, Aaron L; Neeves, Keith B

    2015-01-01

    Intravascular blood clots form in an environment in which hydrodynamic forces dominate and in which fluid-mediated transport is the primary means of moving material. The clotting system has evolved to exploit fluid dynamic mechanisms and to overcome fluid dynamic challenges to ensure that clots that preserve vascular integrity can form over the wide range of flow conditions found in the circulation. Fluid-mediated interactions between the many large deformable red blood cells and the few small rigid platelets lead to high platelet concentrations near vessel walls where platelets contribute to clotting. Receptor-ligand pairs with diverse kinetic and mechanical characteristics work synergistically to arrest rapidly flowing cells on an injured vessel. Variations in hydrodynamic stresses switch on and off the function of key clotting polymers. Protein transport to, from, and within a developing clot determines whether and how fast it grows. We review ongoing experimental and modeling research to understand these and related phenomena.

  20. Genomic DNA Isolation by Phenol/Chloroform Extracting Method from Sheep Blood Clot%酚/氯仿抽提法提取绵羊凝血块中基因组DNA

    Institute of Scientific and Technical Information of China (English)

    曹果清; 莫清珊; 陈凤仙

    2009-01-01

    [Objective] The aim was to establish the method of extracting genomic DNA from sheep blood clot on the basis of the improvement of method for extracting genomic DNA from tissues. [Method]The genomic DNA with complete primary structure and high purity was obtained from the sheep blood clot after the steps of cutting the sheep blood clot with ophthalmic scissors, cell lysis with tissue DNA extracts and digested by proteinase K, extracting with phenol/chloroform and precipitating with ethanol were performed. [Result]The concentration of the extracted DNA was 159.90±0.70 ng/μl and the ratio of the A260/A280 was 1.80+0.01. The sheep microsatellite locus of BM203 was amplified by using the extracted DNA from the sheep blood clot as template of PCR, and the PCR result was perfect. [Conclusion]This method is simple and feasible, the quantity and quality of the extracted DNA can satisfy the demands for the subsequent researches. It is worth to extending and using for reference.%[目的]对组织DNA提取方法进行改进,建立一种从绵羊凝血块中提取基因组DNA的方法.[方法]将绵羊凝血块用眼科剪剪碎,用组织DNA抽提液裂解细胞,用蛋白酶K消化后,经过酚/氯仿抽提,无水乙醇沉淀获得基因组DNA.用NanoDrop ND-1000微型分光光度计检测DNA浓度和纯度.用0.8%琼脂糖凝胶电泳检验基因组DNA的完整性.以绵羊微卫星位点BM203为扩增位点,分别以F:5′-GGGTGTGACATTTTGTTCCC-3′,R:5′-CTGCTCGCCACTAGTCCTTC-3′为上下游引物,进行PCR扩增试验.PCR产物用1.5%琼脂糖凝胶电泳检测.[结果]提取的DNA浓度为(159.90±0.70) ng/μl,A260/A280比值为1.80±0.01,分子完整,结果理想.以从凝血块中提取的DNA为模板,对绵羊BM203微卫星位点进行了PCR扩增,扩增产物条带整齐、明亮、特导性强,扩增效果好.[结论]该方法简单、实用,提取的DNA可满足后续相关研究对DNA质量的要求,值得推广借鉴.

  1. Investigation of sol-gel transition by rheological methods. Part I. Experimental methods.

    Directory of Open Access Journals (Sweden)

    KUDRYAVTSEV Pavel Gennadievich

    2017-08-01

    Full Text Available In this work rheological studies of the gelling process were carried out. We have developed a measuring system for studying the rheology of the gelation process. It consisted of several measuring cells of the Weiler-Rebinder type, system for automatic regulation of the composition of the medium and hermostabilization system. This complex is designed to measure the dependence of the value of the ultimate shear stress as a function of time, from the start of the sol-gel transition to the complete conversion of the sol to the gel. The developed device has a wide range of measured values of critical shear stresses τ0 = (0,05÷50000 Dyne/cm2. Using the developed instrument, it was possible to establish the shape of the initial section of the curve τ0 = f(t and develop a methodology for more accurate determination of gelation time. The developed method proved that the classical method for determining the start time of the sol-gel transition using the point of intersection of the tangent to the linear part of the rheological curve τ0 = f(t,gives significantly distorted results. A new phenomenon has been discovered: the kinetic curves in the coordinates of the Avrami-Erofeev-Bogolyubov equation have an inflection point which separates the kinetic curve into two parts, the initial and the final. It was found that the constant k in the Avrami–Erofeev–Bogolyubov quation does not depend on the temperature and is the same for both the initial and final parts of the kinetic curve. It depends only on the chemical nature of the reacting system. It was found that for the initial section of the kinetic curves, the value of the parameter n in the Avrami-Erofeev-Bogolyubov equation was n = 23,4±2,8 and, unlike the final section of the rheological curve, does not depend on temperature. A large value of this parameter can be interpreted as the average number of directions of growth of a fractal aggregate during its growth. The value of this parameter depends

  2. Preparation and characterization of bismuth ruthenate pyrochlore via solid state reaction and sol-gel methods

    Directory of Open Access Journals (Sweden)

    Mayuree Sansernnivet

    2010-01-01

    Full Text Available Bismuth ruthenate pyrochlores, potential cathode materials for intermediate temperature solid oxide fuel cells(ITSOFCs, were prepared via solid-state and sol-gel method. Effects of the preparation routes and conditions on the phase and microstructures of the materials were investigated in this study using XRD and SEM. The study showed that the preparation method and the adding sequence of the starting meterials have a significant effect on the crystal phase and the particle size obtained. Sol-gel synthesis could yield a material with only pyrochlore structure, i.e. Bi2Ru2O7, while the solid state method yielded powder with a small amount of the secondary RuO2 phase. The sol-gel synthesis resulted in materialswith a finer particle size (~0.3-1.0 μm compared to powder synthesized via the solid state reaction method.

  3. A useful method to overcome the difficulties of applying silicone gel sheet on irregular surfaces.

    Science.gov (United States)

    Grella, Roberto; Nicoletti, Gianfranco; D'Ari, Antonio; Romanucci, Vincenza; Santoro, Mariangela; D'Andrea, Francesco

    2015-04-01

    To date, silicone gel and silicone occlusive plates are the most useful and effective treatment options for hypertrophic scars (surgical and traumatic). Use of silicone sheeting has also been demonstrated to be effective in the treatment of minor keloids in association with corticosteroid intralesional infiltration. In our practice, we encountered four problems: maceration, rashes, pruritus and infection. Not all patients are able to tolerate the cushion, especially children, and certain anatomical regions as the face and the upper chest are not easy to dress for obvious social, psychological and aesthetic reasons. In other anatomical regions, it is also difficult to obtain adequate compression and occlusion of the scar. To overcome such problems of applying silicone gel sheeting, we tested the use of liquid silicone gel (LSG) in the treatment of 18 linear hypertrophic scars (HS group) and 12 minor keloids (KS group) as an alternative to silicone gel sheeting or cushion. Objective parameters (volume, thickness and colour) and subjective symptoms such as pain and pruritus were examined. Evaluations were made when the therapy started and after 30, 90 and 180 days of follow-up. After 90 days of treatment with silicone gel alone (two applications daily), HS group showed a significant improvement in terms of volume decrease, reduced inflammation and redness and improved elasticity. In conclusion, on the basis of our clinical data, we find LSG to be a useful method to overcome the difficulties of applying silicone gel sheeting on irregular surface.

  4. Preparation of ZnO crystal by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new method to prepare ZnO crystal was put forward. The preparation process was studied and the mechanism of this method was also discussed. The results show that the sol particles will aggregate when being dehydrated and will form into hard compact gel body through the hard agglomeration between particles. This dry gel is a hard compact agglomeration composed of the first sol particles. At high sintering temperature, the small compacted particles will easily grow up and form a fine ZnO crystal.

  5. Standard Test Method for Gel Time of Carbon Fiber-Epoxy Prepreg

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1999-01-01

    1.1 This test method covers the determination of gel time of carbon fiber-epoxy tape and sheet. The test method is suitable for the measurement of gel time of resin systems having either high or low viscosity. 1.2 The values stated in SI units are to be regarded as standard. The values in parentheses are for reference only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  6. Mechanical stability and fibrinolytic resistance of clots containing fibrin, DNA, and histones.

    Science.gov (United States)

    Longstaff, Colin; Varjú, Imre; Sótonyi, Péter; Szabó, László; Krumrey, Michael; Hoell, Armin; Bóta, Attila; Varga, Zoltán; Komorowicz, Erzsébet; Kolev, Krasimir

    2013-03-08

    Neutrophil extracellular traps are networks of DNA and associated proteins produced by nucleosome release from activated neutrophils in response to infection stimuli and have recently been identified as key mediators between innate immunity, inflammation, and hemostasis. The interaction of DNA and histones with a number of hemostatic factors has been shown to promote clotting and is associated with increased thrombosis, but little is known about the effects of DNA and histones on the regulation of fibrin stability and fibrinolysis. Here we demonstrate that the addition of histone-DNA complexes to fibrin results in thicker fibers (increase in median diameter from 84 to 123 nm according to scanning electron microscopy data) accompanied by improved stability and rigidity (the critical shear stress causing loss of fibrin viscosity increases from 150 to 376 Pa whereas the storage modulus of the gel increases from 62 to 82 pascals according to oscillation rheometric data). The effects of DNA and histones alone are subtle and suggest that histones affect clot structure whereas DNA changes the way clots are lysed. The combination of histones + DNA significantly prolongs clot lysis. Isothermal titration and confocal microscopy studies suggest that histones and DNA bind large fibrin degradation products with 191 and 136 nM dissociation constants, respectively, interactions that inhibit clot lysis. Heparin, which is known to interfere with the formation of neutrophil extracellular traps, appears to prolong lysis time at a concentration favoring ternary histone-DNA-heparin complex formation, and DNase effectively promotes clot lysis in combination with tissue plasminogen activator.

  7. Mechanical Stability and Fibrinolytic Resistance of Clots Containing Fibrin, DNA, and Histones*

    Science.gov (United States)

    Longstaff, Colin; Varjú, Imre; Sótonyi, Péter; Szabó, László; Krumrey, Michael; Hoell, Armin; Bóta, Attila; Varga, Zoltán; Komorowicz, Erzsébet; Kolev, Krasimir

    2013-01-01

    Neutrophil extracellular traps are networks of DNA and associated proteins produced by nucleosome release from activated neutrophils in response to infection stimuli and have recently been identified as key mediators between innate immunity, inflammation, and hemostasis. The interaction of DNA and histones with a number of hemostatic factors has been shown to promote clotting and is associated with increased thrombosis, but little is known about the effects of DNA and histones on the regulation of fibrin stability and fibrinolysis. Here we demonstrate that the addition of histone-DNA complexes to fibrin results in thicker fibers (increase in median diameter from 84 to 123 nm according to scanning electron microscopy data) accompanied by improved stability and rigidity (the critical shear stress causing loss of fibrin viscosity increases from 150 to 376 Pa whereas the storage modulus of the gel increases from 62 to 82 pascals according to oscillation rheometric data). The effects of DNA and histones alone are subtle and suggest that histones affect clot structure whereas DNA changes the way clots are lysed. The combination of histones + DNA significantly prolongs clot lysis. Isothermal titration and confocal microscopy studies suggest that histones and DNA bind large fibrin degradation products with 191 and 136 nm dissociation constants, respectively, interactions that inhibit clot lysis. Heparin, which is known to interfere with the formation of neutrophil extracellular traps, appears to prolong lysis time at a concentration favoring ternary histone-DNA-heparin complex formation, and DNase effectively promotes clot lysis in combination with tissue plasminogen activator. PMID:23293023

  8. Dye-Sensitized Solar Cells with Optimal Gel Electrolyte Using the Taguchi Design Method

    Directory of Open Access Journals (Sweden)

    Jenn-Kai Tsai

    2013-01-01

    Full Text Available The Taguchi method was adopted to determine the optimal gel electrolyte used in dye-sensitized solar cells (DSSCs. Since electrolyte is a very important factor in fabrication of high performance and long-term stability DSSCs, to find the optimal composition of gel electrolyte is desired. In this paper, the common ingredients used in the liquid electrolyte were chosen. The ingredients then mixed with cheap ionic liquids and poly(vinylidenefluoride-co-hexafluoropropylene (PVDF-HFP were added to form colloidal electrolyte (gel. The optimal composition of each materials in the gel electrolyte determined by Taguchi method consists of 0.03 M I2, 0.15 M KI, 0.6 M LiI, 0.5 M 4-tertbutylpyridine (TBP, and 10% PVDF-HFP dissolved in the acetonitrile and 3-methoxypropionitrile (MPN solution with volume ratio of 2 : 1. The short circuit current density of 14.11 mA/cm2, the conversion efficiency (η of 5.52%, and the lifetime of over 110 days were observed for the dye-sensitized solar cell assembled with optimal gel electrolyte. The lifetime increases 10 times when compared with the conventional dye-sensitized solar cell assembled with liquid electrolyte.

  9. Fibronectin provides a conduit for fibroblast transmigration from collagenous stroma into fibrin clot provisional matrix.

    Science.gov (United States)

    Greiling, D; Clark, R A

    1997-04-01

    After injury, the wound space is filled with a fibrin/fibronectin clot containing growth factors released by platelets and monocytes. In response to these factors, fibroblasts migrate into the fibrin clot and contribute to the formation of granulation tissue. The functional mechanisms allowing fibroblasts to leave the collagenous matrix of normal connective tissue and invade the provisional matrix of the fibrin clot have not been fully defined. To investigate these mechanisms we established a new in vitro model which simulates specific aspects of early wound healing, that is, the migration of fibroblasts from a three-dimensional collagen matrix into a fibrin clot. This transmigration could be induced by physiological concentrations of platelet releasate or platelet-derived growth factor BB (PDGF-BB) in a concentration-dependent manner. At 24 hours irradiated fibroblasts invaded the fibrin gel almost as well as non-irradiated cells, indicating that transmigration was independent of proliferation. Plasminogen and its activators appear to be necessary for invasion of the fibrin clot since protease inhibitors decreased the amount of migration. These serine proteases, however, were not necessary for exit from the collagen gel as fibroblasts migrated out of the collagen gel onto a surface coated with fibrin fibrils even in the presence of inhibitors. Removal of fibronectin (FN) from either the collagen gel or the fibrin gel markedly decreased the number of migrating cells, suggesting that FN provides a conduit for transmigration. Cell movement in the in vitro model was inhibited by RGD peptide, and by monoclonal antibodies against the subunits of the alpha5 beta1 and alpha v beta3 integrin receptor. Thus, the functional requirements for fibroblast transmigration from collagen-rich to fibrin-rich matrices, such as occurs in early wound healing, have been partially defined using an in vitro paradigm of this important biologic process.

  10. Zinc promotes clot stability by accelerating clot formation and modifying fibrin structure.

    Science.gov (United States)

    Henderson, Sara J; Xia, Jing; Wu, Huayin; Stafford, Alan R; Leslie, Beverly A; Fredenburgh, James C; Weitz, David A; Weitz, Jeffrey I

    2016-03-01

    Zinc released from activated platelets binds fibrin(ogen) and attenuates fibrinolysis. Although zinc also affects clot formation, the mechanism and consequences are poorly understood. To address these gaps, the effect of zinc on clot formation and structure was examined in the absence or presence of factor (F) XIII. Zinc accelerated a) plasma clotting by 1.4-fold, b) fibrinogen clotting by 3.5- and 2.3-fold in the absence or presence of FXIII, respectively, c) fragment X clotting by 1.3-fold, and d) polymerisation of fibrin monomers generated with thrombin or batroxobin by 2.5- and 1.8-fold, respectively. Whereas absorbance increased up to 3.3-fold when fibrinogen was clotted in the presence of zinc, absorbance of fragment X clots was unaffected by zinc, consistent with reports that zinc binds to the αC-domain of fibrin(ogen). Scanning electron microscopic analysis revealed a two-fold increase in fibre diameter in the presence of zinc and in permeability studies, zinc increased clot porosity by 30-fold with or without FXIII. Whereas FXIII increased clot stiffness from 128 ± 19 Pa to 415 ± 27 Pa in rheological analyses, zinc reduced clot stiffness by 10- and 8.5-fold in the absence and presence of FXIII, respectively. Clots formed in the presence of zinc were more stable and resisted rupture with or without FXIII. Therefore, zinc accelerates clotting and reduces fibrin clot stiffness in a FXIII-independent manner, suggesting that zinc may work in concert with FXIII to modulate clot strength and stability.

  11. 人血凝块提取基因组DNA碘化钾法建立%Potassium iodide method:a qiuck way of genomic DNA extraction from human blood clotting

    Institute of Scientific and Technical Information of China (English)

    魏俊; 张珍真; 朱惠莲; 黄演林; 林森彬; 刘鹏

    2011-01-01

    目的 通过与酚/氯仿法比较,建立一种快速、经济、高效从人血凝块提取基因组DNA的简易方法.方法采用双蒸水低渗破碎红细胞,碘化钾直接、快速裂解白细胞及其核膜,氯仿/异戊醇沉淀蛋白质及残存细胞碎片,最后经异丙醇和乙醇沉淀基因组DNA.结果 采用该法提取的基因组DNA浓度为(46.4±8.8)mg/L,吸光度值A260/A280为(1.79±0.23),与酚/氯仿法(46.1±8.3,1.78±0.22)比较差异无统计学意义(P>0.05);2种方法 提取基因组DNA凝胶电泳条带完整,PCR扩增目的 条带完整,能够满足分子生物学实验要求.结论 碘化钾法是一种快速、简便、经济、高效提取人血凝块基因组DNA的方法,可以广泛运用于大规模人群基因组学研究.%Objective To establish a simple,quick and economical method for genomic DNA extraction from human blood clotting compared with traditional phenol-chloroform method. Methods Double distilled water was used to lyse red blood cells (RBC) and saturated potassium iodide to lyse white blood cells (WBC) and its nuclear membrane. Chloroform and isoamyl alcohol was used to precipitate proteins and the residues of cells. The the genomic DNA was precipitated by isopropanol and ethanol. Results The average quantity of genomic DNA extracted was 46.4 ± 8.8mg/L and the ratio of A260/A280 was 1.79 ± 0.23. Furthermore, no statistical signifcance was observed when compared with phenol-chloroform method. The electrophoretic bands of genomic DNA and PCR amplification products were distinct,and the extracted genomic DNA reached the standard for molecular biological experiment. Conclusion The postassium iodide method is a simple,quick,economical and efficient way for genomic DNA extraction from human blood clotting, and could be used in large genomics study.

  12. Characterization of Sr{beta}-alumina prepared by sol-gel and spray pyrolysis methods

    Energy Technology Data Exchange (ETDEWEB)

    Kalaignan, G. Paruthimal; Seo, Dae Jong; Park, Seung Bin

    2004-06-15

    Eu{sup 2+} doped {beta}-alumina, Sr{sub 1-x}MgAl{sub 10}O{sub 17} Eu{sub x}{sup 2+} (x=0.01-0.07) were successfully prepared by sol-gel and spray pyrolysis techniques with the same precursor materials. Sr{beta}-alumina doped with Eu{sup 2+} (SrMgAl{sub 10}O{sub 17}:Eu{sup 2+}) prepared from sol-gel method showed three photoluminescence (PL) peaks at 390, 418 and 459 nm after excitation wavelength at 254 nm and one PL peak at 461 nm when excitation was at 365 nm. The same powder was prepared from spray pyrolysis technique showed the six PL peaks at 323, 397, 415, 443, 480 and 508 nm after excitation at 254 nm. Also two PL peaks at 440 and 480 nm were observed after the excitation at 365 nm. These PL peaks were dependent on the excitation wavelength. The effect of different annealing temperatures of sol-gel powders, preparation conditions of spray pyrolysis powders and reduction atmospheres of both sol-gel and spray pyrolysis powders of various compositions of Eu{sup 2+} doped Sr{beta}-alumina were also studied. Both the powders were characterized by scanning electron microscopy, X-ray diffraction and PL techniques and comparison between the two preparation methods. Sol-gel prepared powder had eight times higher PL intensity and brightness than the spray pyrolysis prepared powder. The suggested good composition of Sr{beta}-alumina is Sr{sub 0.93}MgAl{sub 10}O{sub 17}:Eu{sub 0.07} for both sol-gel and spay pyrolysis methods.

  13. Method for preparing hydrous titanium oxide spherules and other gel forms thereof

    Science.gov (United States)

    Collins, J.L.

    1998-10-13

    The present invention are methods for preparing hydrous titanium oxide spherules, hydrous titanium oxide gels such as gel slabs, films, capillary and electrophoresis gels, titanium monohydrogen phosphate spherules, hydrous titanium oxide spherules having suspendible particles homogeneously embedded within to form a composite sorbent, titanium monohydrogen phosphate spherules having suspendible particles of at least one different sorbent homogeneously embedded within to form a composite sorbent having a desired crystallinity, titanium oxide spherules in the form of anatase, brookite or rutile, titanium oxide spherules having suspendible particles homogeneously embedded within to form a composite, hydrous titanium oxide fiber materials, titanium oxide fiber materials, hydrous titanium oxide fiber materials having suspendible particles homogeneously embedded within to form a composite, titanium oxide fiber materials having suspendible particles homogeneously embedded within to form a composite and spherules of barium titanate. These variations of hydrous titanium oxide spherules and gel forms prepared by the gel-sphere, internal gelation process offer more useful forms of inorganic ion exchangers, catalysts, getters and ceramics. 6 figs.

  14. Fabrication of ultrathin films of Ta2O5 by a sol-gel method

    NARCIS (Netherlands)

    Wolf, M.J.; Roitsch, J.; Mayer, J.; Nijmeijer, A.; Bouwmeester, H.J.M.

    2013-01-01

    Tantalum oxide (Ta2O5) is widely known for its high chemical, thermal and hydrothermal stability. In this study, a sol–gel method has been developed to produce homogenous, i.e., defect and pin-hole free, ultrathin films of Ta2O5. These were coated onto a porous substrate by means of dip-coating, and

  15. Luminescent Thin Film of Doped Terbium Complex Obtained by Sol-Gel Method

    Institute of Scientific and Technical Information of China (English)

    刘丰祎; 符连社; 王俊; 李焕荣; 张洪杰

    2003-01-01

    The transparent luminescent thin films of doped terbium complex were obtained by sol-gel method. The result indicates that rare earth carboxylates with poor solubility can be homogeneously doped into sol matrix in situ. The fluorescence spectra show that the thin film material emits the characteristic narrow band emission of Tb3+ under the UV excitation.

  16. Preparation of long alumina fibers by sol-gel method using tartaric acid

    Science.gov (United States)

    Tan, Hong-Bin

    2011-12-01

    Long alumina fibers were prepared by sol-gel method. The spinning sol was obtained by mixing aluminum nitrate, tartaric acid, and polyvinylpyrrolidone with a mass ratio of 10:3:1.5. Thermogravimetry-differential scanning calorimetry (TG-DSC), Fourier transform infrared (FT-IR) spectra, X-ray diffraction (XRD), and scanning electron microscopy (SEM) were used to characterize the properties of the gel and ceramic fibers. A little of α-Al2O3 phase is observed in the alumina precursor gel fibers sintered at 1273 K. The fibers with a uniform diameter can be obtained when sintered at 1473 K, and its main phase is also indentified as α-Al2O3.

  17. Emission of Eu3+in sol-gel oxyfluoride glass materials obtained by different preparation methods

    Institute of Scientific and Technical Information of China (English)

    M. Żądło; B. Szpikowska-Sroka; L. Żur; R. Czoik; W.A. Pisarski

    2014-01-01

    Silica glasses doped with Eu3+ions prepared by sol-gel methods were investigated. The X-ray diffraction (XRD) was used to verify the nature of the studied systems. Excitation and emission spectra of Eu3+ ions in sol-gel glass materials were detected. Red-to-orange luminescence intensity ratios R/O related to integrated intensities of 5D0→7F2 to 5D0→7F1 transitions and luminescence lifetimes for 5D0 state of Eu3+ions were determined. The results indicated that spectroscopic parameters for Eu3+ions strongly de-pended on reagents and their relative ratios used for sol-gel glass preparation.

  18. A sol-gel method to synthesize indium tin oxide nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Xiuhua Li; Xiujuan xu; Xin Yin; Chunzhong Li; Jianrong Zhang

    2011-01-01

    Transparent conductive indium tin oxide (ITO) nanoparticles were synthesized by a novel sol-gel method.Granulated indium and tin were dissolved in HNO3 and partially complexed with citric acid.A sol-gel process was induced when tertiary butyl alcohol was added dropwise to the above solution.ITO nanoparticles with an average crystallite size of 18.5 nm and surface area of 32.6 m2/g were obtained after the gel was heat-treated at 700 C.The ITO nanoparticles showed good sinterability,the starting sintering temperature decreased sharply to 900 C,and the 1400 C sintered pellet had a density of 98.1 % of theoretical density (TD).

  19. Photoacoustic monitoring of clot formation during surgery and tumor surgery

    Science.gov (United States)

    Juratli, Mazen A.; Galanzha, Ekaterina I.; Sarimollaoglu, Mustafa; Nedosekin, Dmitry A.; Suen, James Y.; Zharov, Vladimir P.

    2013-03-01

    When a blood vessel is injured, the normal physiological response of the body is to form a clot (thrombus) to prevent blood loss. Alternatively, even without injury to the blood vessel, the pathological condition called thromboembolism may lead to the formation of circulating blood clots (CBCs), also called emboli, which can clog blood vessels throughout the body. Veins of the extremities (venous thromboembolism), lungs (pulmonary embolism ), brain (embolic stroke), heart (myocardial infarction), kidneys, and gastrointestinal tract are often affected. Emboli are also common complications of infection, inflammation, cancer, surgery, radiation and coronary artery bypass grafts. Despite the clear medical significance of CBCs, however, little progress has been made in the development of methods for real-time detection and identification of CBCs. To overcome these limitations, we developed a new modification of in vivo photoacoustic (PA) flow cytometry (PAFC) for real-time detection of white, red, and mixed clots through a transient decrease, increase or fluctuation of PA signal amplitude, respectively. In this work, using PAFC and mouse models, we present for the first time direct evidence that some medical procedures, such as conventional or cancer surgery may initiate the formation of CBCs. In conclusion, the PA diagnostic platform can be used in real-time to define risk factors for cardiovascular diseases, assist in the prognosis and potential prevention of stroke by using a well-timed therapy or as a clot count as a marker of therapy efficacy.

  20. Alignment of the Fibrin Network Within an Autologous Plasma Clot.

    Science.gov (United States)

    Gessmann, Jan; Seybold, Dominik; Peter, Elvira; Schildhauer, Thomas Armin; Köller, Manfred

    2016-01-01

    Autologous plasma clots with longitudinally aligned fibrin fibers could serve as a scaffold for longitudinal axonal regrowth in cases of traumatic peripheral nerve injuries. Three different techniques for assembling longitudinally oriented fibrin fibers during the fibrin polymerization process were investigated as follows: fiber alignment was induced by the application of either a magnetic field or-as a novel approach-electric field or by the induction of orientated flow. Fiber alignment was characterized by scanning electron microscopy analysis followed by image processing using fast Fourier transformation (FFT). Besides FFT output images, area xmin to xmax, as well as full width at half maximum (FWHM) of the FFT graph plot peaks, was calculated to determine the relative degree of fiber alignment. In addition, fluorescently labeled human fibrinogen and mesenchymal stem cells (MSCs) were used to visualize fibrin and cell orientation in aligned and nonaligned plasma clots. Varying degrees of fiber alignment were achieved by the three different methods, with the electric field application producing the highest degree of fiber alignment. The embedded MSCs showed a longitudinal orientation in the electric field-aligned plasma clots. The key feature of this study is the ability to produce autologous plasma clots with aligned fibrin fibers using physical techniques. This orientated internal structure of an autologous biomaterial is promising for distinct therapeutic applications, such as a guiding structure for cell migration and growth dynamics.

  1. Blood clot detection using magnetic nanoparticles

    Science.gov (United States)

    Khurshid, Hafsa; Friedman, Bruce; Berwin, Brent; Shi, Yipeng; Ness, Dylan B.; Weaver, John B.

    2017-01-01

    Deep vein thrombosis, the development of blood clots in the peripheral veins, is a very serious, life threatening condition that is prevalent in the elderly. To deliver proper treatment that enhances the survival rate, it is very important to detect thrombi early and at the point of care. We explored the ability of magnetic particle spectroscopy (MSB) to detect thrombus via specific binding of aptamer functionalized magnetic nanoparticles with the blood clot. MSB uses the harmonics produced by nanoparticles in an alternating magnetic field to measure the rotational freedom and, therefore, the bound state of the nanoparticles. The nanoparticles’ relaxation time for Brownian rotation increases when bound [A.M. Rauwerdink and J. B. Weaver, Appl. Phys. Lett. 96, 1 (2010)]. The relaxation time can therefore be used to characterize the nanoparticle binding to thrombin in the blood clot. For longer relaxation times, the approach to saturation is more gradual reducing the higher harmonics and the harmonic ratio. The harmonic ratios of nanoparticles conjugated with anti-thrombin aptamers (ATP) decrease significantly over time with blood clot present in the sample medium, compared with nanoparticles without ATP. Moreover, the blood clot removed from the sample medium produced a significant MSB signal, indicating the nanoparticles are immobilized on the clot. Our results show that MSB could be a very useful non-invasive, quick tool to detect blood clots at the point of care so proper treatment can be used to reduce the risks inherent in deep vein thrombosis.

  2. New visible and selective DNA staining method in gels with tetrazolium salts.

    Science.gov (United States)

    Paredes, Aaron J; Naranjo-Palma, Tatiana; Alfaro-Valdés, Hilda M; Barriga, Andrés; Babul, Jorge; Wilson, Christian A M

    2017-01-15

    DNA staining in gels has historically been carried out using silver staining and fluorescent dyes like ethidium bromide and SYBR Green I (SGI). Using fluorescent dyes allows recovery of the analyte, but requires instruments such as a transilluminator or fluorimeter to visualize the DNA. Here we described a new and simple method that allows DNA visualization to the naked eye by generating a colored precipitate. It works by soaking the acrylamide or agarose DNA gel in SGI and nitro blue tetrazolium (NBT) solution that, when exposed to sunlight, produces a purple insoluble formazan precipitate that remains in the gel after exposure to light. A calibration curve made with a DNA standard established a detection limit of approximately 180 pg/band at 500 bp. Selectivity of this assay was determined using different biomolecules, demonstrating a high selectivity for DNA. Integrity and functionality of the DNA recovered from gels was determined by enzymatic cutting with a restriction enzyme and by transforming competent cells after the different staining methods, respectively. Our method showed the best performance among the dyes employed. Based on its specificity, low cost and its adequacy for field work, this new methodology has enormous potential benefits to research and industry.

  3. Protein-phospholipid interactions in blood clotting.

    Science.gov (United States)

    Morrissey, James H; Davis-Harrison, Rebecca L; Tavoosi, Narjes; Ke, Ke; Pureza, Vincent; Boettcher, John M; Clay, Mary C; Rienstra, Chad M; Ohkubo, Y Zenmei; Pogorelov, Taras V; Tajkhorshid, Emad

    2010-04-01

    Most steps of the blood clotting cascade require the assembly of a serine protease with its specific regulatory protein on a suitable phospholipid bilayer. Unfortunately, the molecular details of how blood clotting proteins bind to membrane surfaces remain poorly understood, owing to a dearth of techniques for studying protein-membrane interactions at high resolution. Our laboratories are tackling this question using a combination of approaches, including nanoscale membrane bilayers, solid-state NMR, and large-scale molecular dynamics simulations. These studies are now providing structural insights at atomic resolution into clotting protein-membrane interactions. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  4. Quantifying platelet gel coagulation using Sonoclot and Thrombelastograph hemostasis analyzer.

    Science.gov (United States)

    Cassidy, Lynsay K; Finney, Angela S; Ellis, William Cory; Spiwak, Allison J; Riley, Jeffrey B

    2005-03-01

    Little in vitro research exists discussing platelet gel composition and the resulting strength and degradation characteristics using point-of-care technologies. There must be a quantifiable way of determining the structural integrity of the resulting formed platelet gel thrombus. The Thrombelastograph Hemostasis Analyzer (TEG) and Sonoclot measure the elasticity of a clot as it forms and subsequently degrades naturally. The objective of this study was to determine the application of TEG and Sonoclot technologies as point-of-care devices for technicians using platelet gel therapy. The collected bovine blood was anticoagulated with CPD and processed using a previously published plasma sequestration protocol, using normal saline as a wash solution. The resulting platelet-rich plasma was stored in a sequestration bag in a water bath to maintain the blood temperature at 37 degrees C. Sequestered bovine platelet-rich plasma was made into platelet gel using three different thrombin concentrations. A total of 30 experiments were performed on the platelet gel product using both the TEG and the Sonoclot. We discovered that 6 of the Sonoclot tests and 15 of the TEG tests were valid. None of the TEG clot signatures and nine of the Sonoclot signatures were discovered to be invalid. A chi2 test was performed on the resultant data. The value of the chi2 test was calculated to be 12.86, which translated into a p value of less than 0.001. Despite the vast use and growing popularity of platelet gels, a method in which to quantify platelet gels has yet to be reported. There remains a possibility that gels formed with different concentrations of components may prove useful in different areas of surgery or their uses may expand to a broader spectrum of medicine. However, technology to quantify platelet gels must first be standardized. On the basis of the data collected in this study, it was determined that the TEG and the Sonoclot are not equally capable of analyzing platelet gel clots

  5. Superovulation with a single administration of FSH in aluminum hydroxide gel: a novel superovulation method for cattle.

    Science.gov (United States)

    Kimura, Koji

    2016-10-18

    Superovulation (SOV) is a necessary technique to produce large numbers of embryos for embryo transfer. In the conventional methods, follicular stimulating hormone (FSH) is administered to donor cattle twice daily for 3 to 4 days. As this method is labor intensive and stresses cattle, improving this method has been desired. We previously developed a novel and simple SOV method, in which the intramuscular injection of a single dose of FSH in aluminum hydroxide gel (AH-gel) induced the growth of multiple follicles, ovulation and the production of multiple embryos. Here we show that AH-gel can efficiently adsorb FSH and release it effectively in the presence of BSA, a major interstitial protein. When a single intramuscular administration of the FSH and AH-gel mixture was performed to cattle, multiple follicular growth, ovulation and embryo production were induced. However, the treatments caused indurations at the administration sites in the muscle. To reduce the muscle damage, we investigated alternative administration routes and different amounts of aluminum in the gel. By administering the FSH in AH-gel subcutaneously rather than intramuscularly, the amount of aluminum in the gel could be reduced, thus reducing the size of the induration. Moreover, repeated administrations of FSH with AH-gel did not affect the superovulatory response. These results indicate that a single administration of FSH with AH-gel is an effective, novel and practical method for SOV treatment.

  6. Synthetic Hormones and Clot Formation.

    Science.gov (United States)

    Swanepoel, Albe C; Visagie, Amcois; Pretorius, Etheresia

    2016-08-01

    Combined oral contraceptives (COCs), colloquially referred to as "the pill," have been regarded as a medical breakthrough, as they have improved the lives of countless women, from simplifying family planning to the treatment of acne, endometriosis, polycystic ovarian syndrome, and dysmenorrhea. Unfortunately, COC usage has been associated with an increased occurrence of venous thrombosis and therefore a systemic hypercoagulable state in susceptible females. Here we discuss the health risks of COC usage and use viscoelastic and morphological techniques to investigate the effect of different COC constituents on clot formation, particularly fibrin network packaging and whole blood viscoelasticity. Viscoelastic properties of whole blood showed gender-specific changes while morphological alterations were person-specific, regardless of gender. Using scanning electron microscopy and thromboelastography provides great insight regarding fibrin packaging and the development of a hypercoagulable state in high-risk individuals. We proposed a three-step approach where (1) an individual's coagulation profile baseline is determined, after which (2) the "ideal" combination of constituents is prescribed, and (3) the coagulation profile of the individual is monitored to assess possible risk of thrombosis. Only in following such an individualized patient-oriented approach will we be able to avoid the many health issues due to COC usage in susceptible females.

  7. Zirconia coatings deposited by novel plasma-enhanced aerosol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Miszczak, Sebastian; Pietrzyk, Bozena; Kucharski, Daniel [Institute of Materials Science and Engineering, Lodz University of Technology (Poland)

    2016-05-15

    The sol-gel technique is well known and widely used for manufacturing coatings. An aerosol-gel method is a modification of the classic sol-gel process. Preparation of coatings by this technique involves the formation of an aerosol and its deposition on the coated surfaces, where the aerosol droplets merge into a continuous layer. In this work, an aerosol-gel routine, enhanced with a low-temperature plasma discharge, was used to produce zirconia coatings on different substrates. Low-temperature plasma was used for preactivation of substrate surfaces prior to the sol deposition, and for treatment of deposited layers. The obtained coatings were characterized using optical, electron (SEM), and atomic force (AFM) microscopes, a contact-angle device, a scratch tester, a grazing-incidence X-ray diffractometer (GIXRD), and an infrared spectrometer (FTIR). The results showed a significant influence of substrate plasma pretreatment on the formation and morphology of zirconia thin films. A noticeable effect of low-temperature plasma treatment on the structure and properties of the obtained coatings was also presented. These results allow possible applications of this method for the preparation of zirconia coatings on temperature-sensitive substrates to be predicted. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Synthesis and Characterization of NASICON Nanoparticles by Sol-gel Method

    Institute of Scientific and Technical Information of China (English)

    WANG Biao; LIANG Xi-shuang; LIU Feng-min; ZHONG Tie-gang; ZHAO Chun; LU Ge-yu; QUAN Bao-fu

    2009-01-01

    Na superionic conductor(NASICON) nanoparticles were synthesized by a modified sol-gel method and sintered at a temperature range of 800-1000 ℃. The performance of the samples was characterized by the analysis methods of X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR), and transmission electron microscopy(TEM) as well as conductivity measurement. Compared with those sintered at other temperatures, the NASICON material sintered at 900 ℃ had the best crystalline structure and higher conductivity.

  9. THERMALLY STABLE NANOCRYSTALLINE TIO2 PHOTOCATALYSTS SYNTHESIZED VIA SOL-GEL METHODS MODIFIED WITH IONIC LIQUID AND SURFACTANT MOLECULES

    Science.gov (United States)

    Recently, sol-gel methods employing ionic liquids (ILs) have shown significant implications for the synthesis of well-defined nanostructured inorganic materials. Herein, we synthesized nanocrystalline TiO2 particles via an alkoxide sol-gel method employing a water-immi...

  10. A Novel Method for Detection of Glycoproteins on Sodium Dodecyl Sulphate Polyacrylamide Gel Using Radio-Iodinated Tyrosine

    DEFF Research Database (Denmark)

    Nalla, Amarnadh; Draz, Hossam M.; Dole, Anita;

    2009-01-01

    The aim of this study is to develop a novel method for detection of glycoproteins on polyacrylamide gel. In this method, radio-iodinated-tyrosine (125I-tyrosine) was conjugated to glycoprotein by schiff's base mechanism on the sodium dodecyl sulfate- polyacrylamide gel. Ovalbumin and Concanavalin...

  11. THERMALLY STABLE NANOCRYSTALLINE TIO2 PHOTOCATALYSTS SYNTHESIZED VIA SOL-GEL METHODS MODIFIED WITH IONIC LIQUID AND SURFACTANT MOLECULES

    Science.gov (United States)

    Recently, sol-gel methods employing ionic liquids (ILs) have shown significant implications for the synthesis of well-defined nanostructured inorganic materials. Herein, we synthesized nanocrystalline TiO2 particles via an alkoxide sol-gel method employing a water-immi...

  12. Preventing Blood Clots After Orthopaedic Surgery

    Medline Plus

    Full Text Available ... Surgeons. Many of the images included in this video are courtesy of Thinkstock ©2013. Warning Signs It is important to follow your doctor's instructions carefully to minimize the risk for blood clots ...

  13. Preventing Blood Clots After Orthopaedic Surgery

    Medline Plus

    Full Text Available ... of a blood clot within a deep vein. It commonly occurs in the thigh or calf. Deep ... breaks free and travels through the veins. If it reaches the lungs, it can block the flow ...

  14. Preventing Blood Clots After Orthopaedic Surgery

    Medline Plus

    Full Text Available ... recovery from surgery. Warning Signs of Blood Clots Pain in your calf and leg, unrelated to your ... of Pulmonary Embolism Sudden shortness of breath Chest pain, particularly with breathing Notify your doctor immediately if ...

  15. Preventing Blood Clots After Orthopaedic Surgery

    Medline Plus

    Full Text Available ... Patient Safety Patient Stories Resources Copyright 2017 American Academy of Orthopaedic Surgeons Preventing Blood Clots After Orthopaedic ... about DVT and its prevention. This video © American Academy of Orthopaedic Surgeons. Many of the images included ...

  16. Preventing Blood Clots After Orthopaedic Surgery

    Medline Plus

    Full Text Available ... Bones & Injuries Diseases & Conditions Arthritis Tumors Sports Injuries & Prevention Children Bone Health Health & Safety Treatment Treatments & Surgeries ... Your doctor will outline a program to help prevent the development of blood clots after your surgery. ...

  17. Preventing Blood Clots After Orthopaedic Surgery

    Medline Plus

    Full Text Available ... Bones & Injuries Diseases & Conditions Arthritis Tumors Sports Injuries & Prevention Children Bone Health Health & Safety Treatment Treatments & Surgeries ... Your doctor will outline a program to help prevent the development of blood clots after your surgery. ...

  18. Preventing Blood Clots After Orthopaedic Surgery

    Medline Plus

    Full Text Available ... major risks facing patients who undergo surgery is a complication called deep vein thrombosis. Deep vein thrombosis (DVT) is the formation of a blood clot within a deep vein. It commonly ...

  19. Preventing Blood Clots After Orthopaedic Surgery

    Medline Plus

    Full Text Available ... of a blood clot within a deep vein. It commonly occurs in the thigh or calf. Deep ... breaks free and travels through the veins. If it reaches the lungs, it can block the flow ...

  20. Hydroxyapatite, fluor-hydroxyapatite and fluorapatite produced via the sol–gel method: dissolution behaviour and biological properties after crystallisation

    OpenAIRE

    Tredwin, CJ; Young, AM; Abou Neel, EA; Georgiou, G.; Knowles, JC

    2013-01-01

    Hydroxyapatite (HA), fluor-hydroxyapatite (FHA) with varying levels of fluoride ion substitution and fluorapatite (FA) were synthesised by the sol–gel method as possible implant coating or bone-grafting materials. Cal- cium nitrate and triethyl phosphite were used as precursors under an ethanol–water based solution. Different amounts of ammonium fluoride were incorporated for the preparation of the FHA and FA sol–gels. After heating and powdering the sol–gels, dissolut...

  1. Clotting of mammalian fibrinogens by papain: a re-examination.

    Science.gov (United States)

    Doolittle, Russell F

    2014-10-28

    Papain has long been known to cause the gelation of mammalian fibrinogens. It has also been reported that papain-fibrin is insoluble in dispersing solvents like strong urea or sodium bromide solutions, similar to what is observed with thrombin-generated clots in the presence of factor XIIIa and calcium. In those old studies, both the gelation and subsequent clot stabilization were attributed to papain, although the possibility that the second step might be due to contaminating factor XIII in fibrinogen preparations was considered. I have revisited this problem in light of knowledge acquired over the past half-century about thiol proteases like papain, which mostly cleave peptide bonds, and transglutaminases like factor XIIIa that catalyze the formation of ε-lysyl-γ-glutamyl cross-links. Recombinant fibrinogen, inherently free of factor XIII and other plasma proteins, formed a stable gel when treated with papain alone. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the intermolecular cross-linking in papain-fibrin leads to γ-chain dimers, trimers, and tetramers, just as is the case with thrombin-factor XIIIa-stabilized fibrin. Mass spectrometry of bands excised from gels showed that the cross-linked material is quite different from what occurs with factor XIIIa, however. With papain, the cross-linking occurs between γ chains in neighboring protofibrils becoming covalently linked in a "head-to-tail" fashion by a transpeptidation reaction involving the α-amino group of γ-Tyr1 and a papain cleavage site at γ-Gly403 near the carboxy terminus, rather than by the (reciprocal) "tail-to-tail" manner that occurs with factor XIIIa and that depends on cross-links between γ-Lys406 and γ-Gln398.

  2. Effect of preparation conditions in sol-gel method on yellow phosphor with wide spectrum

    Science.gov (United States)

    Lin, Yenchen; Inoue, Shuhei; Matsumura, Yukihiko; Chen, Jyh-Chen

    2017-01-01

    Among several methods to obtain white light in light emitting diodes (LEDs), mixing blue light with yellow light excited by blue light is the most effective and economical method. However, the quality of white light achieved by this method is poor, making it essential to develop high-quality yellow phosphors. In this study, we synthesized yellow phosphors with broad spectral width by the sol-gel method and studied the effect of various synthetic conditions on their photoluminescence spectra. Consequently, we optimized synthesis conditions for a series of yellow phosphors and found that excess europium doping caused quenching and reduced the quantum yield.

  3. Total protein extraction and 2-D gel electrophoresis methods for Burkholderia species.

    Science.gov (United States)

    Velapatiño, Billie; Zlosnik, James E A; Hird, Trevor J; Speert, David P

    2013-10-15

    The investigation of the intracellular protein levels of bacterial species is of importance to understanding the pathogenic mechanisms of diseases caused by these organisms. Here we describe a procedure for protein extraction from Burkholderia species based on mechanical lysis using glass beads in the presence of ethylenediamine tetraacetic acid and phenylmethylsulfonyl fluoride in phosphate buffered saline. This method can be used for different Burkholderia species, for different growth conditions, and it is likely suitable for the use in proteomic studies of other bacteria. Following protein extraction, a two-dimensional (2-D) gel electrophoresis proteomic technique is described to study global changes in the proteomes of these organisms. This method consists of the separation of proteins according to their isoelectric point by isoelectric focusing in the first dimension, followed by separation on the basis of molecular weight by acrylamide gel electrophoresis in the second dimension. Visualization of separated proteins is carried out by silver staining.

  4. Synthesis of hexagonal barium ferrite nanoparticle by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    DONG Limin; HAN Zhidong; ZHANG Yaoming; WU Ze; ZHANG Xianyou

    2006-01-01

    M-type Ba hexaferrites were successfully synthesized by sol-gel method. Several synthesizing factors, such as pH value, citric acid/metal ion ratio, and dispersion agent were mainly discussed. Fine and pure powders of BaFe12O19 were optimally synthesized under the conditions of the pH value is 7 and citricacid/metal ion ratio is 3. The X-ray diffraction analysis demonstrates that no impurity is observed in the synthesized powders after presintered at 450 ℃ and calcinated at 1100 ℃. SEM observations indicate that the size of the synthesized BaFe12O19 powders is small and uniform distribution. It can also be learned from SEM that the co-synthesizing sol-gel method can be in favor ofthe formation of finer particles.

  5. A Review of Photocatalysts Prepared by Sol-Gel Method for VOCs Removal

    Directory of Open Access Journals (Sweden)

    Ting Ke Tseng

    2010-05-01

    Full Text Available The sol-gel process is a wet-chemical technique (chemical solution deposition, which has been widely used in the fields of materials science, ceramic engineering, and especially in the preparation of photocatalysts. Volatile organic compounds (VOCs are prevalent components of indoor air pollution. Among the approaches to remove VOCs from indoor air, photocatalytic oxidation (PCO is regarded as a promising method. This paper is a review of the status of research on the sol-gel method for photocatalyst preparation and for the PCO purification of VOCs. The review and discussion will focus on the preparation and coating of various photocatalysts, operational parameters, and will provide an overview of general PCO models described in the literature.

  6. Gel-aided sample preparation (GASP)--a simplified method for gel-assisted proteomic sample generation from protein extracts and intact cells.

    Science.gov (United States)

    Fischer, Roman; Kessler, Benedikt M

    2015-04-01

    We describe a "gel-assisted" proteomic sample preparation method for MS analysis. Solubilized protein extracts or intact cells are copolymerized with acrylamide, facilitating denaturation, reduction, quantitative cysteine alkylation, and matrix formation. Gel-aided sample preparation has been optimized to be highly flexible, scalable, and to allow reproducible sample generation from 50 cells to milligrams of protein extracts. This methodology is fast, sensitive, easy-to-use on a wide range of sample types, and accessible to nonspecialists. © 2014 The Authors. PROTEOMICS published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. EFFECT OF ANNEALING ON THE PROPERTIES OF VANADIUM PENTOXIDE FILMS PREPARED BY SOL–GEL METHOD

    OpenAIRE

    YAQIANG LIU; XUELIAN DU; XUEQIN LIU

    2014-01-01

    The vanadium pentoxide (V2O5) films were obtained by using sol–gel procedure and then were annealed at different temperature in air. The effect of different annealing temperatures on the composition, the microstructure, the surface morphology and the optical properties of the films were characterized by methods such as by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and spectral transmittance. The results revealed that the film annealed at 150°C has amorphous structure ...

  8. EFFECT OF ANNEALING ON THE PROPERTIES OF VANADIUM PENTOXIDE FILMS PREPARED BY SOL–GEL METHOD

    OpenAIRE

    YAQIANG LIU; XUELIAN DU; XUEQIN LIU

    2014-01-01

    The vanadium pentoxide (V2O5) films were obtained by using sol–gel procedure and then were annealed at different temperature in air. The effect of different annealing temperatures on the composition, the microstructure, the surface morphology and the optical properties of the films were characterized by methods such as by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and spectral transmittance. The results revealed that the film annealed at 150°C has amorphous structure ...

  9. ORGANIC SOL-GEL METHOD IN THE SYNTHESIS AND CHARACTERIZATION OF ZINC OXIDE NANOPARTICLES

    OpenAIRE

    2014-01-01

    Nanosized Zinc Oxide (ZnO) was synthesized using sol-gel method. The nanomaterials with structure were annealed at different temperatures ranging from 500 to 700°C which were chosen based on the Thermogravimetric (TGA) Analysis. The structure and morphology were characterized by Powder X-Ray Diffraction (PXRD) and Transmission Electron Microscope (TEM), respectively. The PXRD shows the increasing tendency in crystallite size when the annealing temperature increases and the hexagonal struc...

  10. ORGANIC SOL-GEL METHOD IN THE SYNTHESIS AND CHARACTERIZATION OF ZINC OXIDE NANOPARTICLES

    OpenAIRE

    2014-01-01

    Nanosized Zinc Oxide (ZnO) was synthesized using sol-gel method. The nanomaterials with structure were annealed at different temperatures ranging from 500 to 700°C which were chosen based on the Thermogravimetric (TGA) Analysis. The structure and morphology were characterized by Powder X-Ray Diffraction (PXRD) and Transmission Electron Microscope (TEM), respectively. The PXRD shows the increasing tendency in crystallite size when the annealing temperature increases and the hexagonal structure...

  11. Synthesis of piezoelectric nanocrystalline PZT powder by stearic acid gel method

    Institute of Scientific and Technical Information of China (English)

    HAO Junjie; WANG Xiaohui; GUI Zhilun; LI Longtu

    2005-01-01

    PZT nanocrystalline powder was prepared by a stearic acid gel method. The crystallization process from the precursor was monitored by infrared spectroscopy, differential thermal analysis, and thermogravimetric analysis. The nano-sized PZT powder was characterized by X-ray diffraction and transmission electron microscopy. It shows that pure single-phase PZT powder could be obtained at 450℃ for 1 h, and the particle size is about 20 nm. With an increase in the calcination temperature, the PZT crystallite size increased.

  12. In vitro dissolution method for evaluation of buprenorphine in situ gel formulation: A technical note

    OpenAIRE

    Graves, Richard A.; Freeman, Thomas; Tarun K. Mandal

    2007-01-01

    The in situ gel formulation of buprenorphine showed sustained drug release for a prolonged period of time. The drug release from RG 502 followed a linear pattern throughout the dissolution without any significant burst release. The amount of buprenorphine released during the first 30 minutes, irrespective of the type of Resomer or dissolution medium, was less than 3%. Drug release continued over 55 days in phosphate buffer and 35 days in Tween 80. The in vitro dissolution method developed dur...

  13. AFM and XPS Study of Glass Surface Coated with Titania Nanofilms by Sol-Gel Method

    Institute of Scientific and Technical Information of China (English)

    JI Guo-Jun; SHI Zhi-Ming

    2010-01-01

    @@ Ce3+-doped and undoped TiO2 nanofilms are prepared on glass surface using a sol-gel method.Crystal structure,surface morphology,chemical composition and element distribution of both glass substrates and TiO2 films were characterized by x-ray diffractometer(XRD),atomic force microscopy(AFM)and x-ray photoelectron spectroscopy(XPS).

  14. Preparation of Machinable Bioactive Glass-ceramics by Sol-gel Method

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The purpose of this research was to prepare machinable bioactive glass-ceramics by sol-gel method. A multi-component composite sol with great uniformity and stability was first prepared by a 2-step method.The composite sol was then transformed into gel by aging under different temperatures. The gel was dried finally by super critically drying method and sintered to obtain the machinable bioactive glass-ceramics. Effect of thermal treatment on crystallization of the glass-ceramics was investigated by X-ray diffraction (XRD) analysis. Microstructure of the glass-ceramics was observed by Scanning Electron Microscopy (SEM) and the mechanism of machinability was discussed. Phlogopite and hydroxylapatite were identified as main crystal phases by XRD analysis under thermal treatment at 750 ℃ and 950 ℃ for 1.5 h separately. The relative bulk density could achieve 99%under 1050 ℃ for 4 h. Microstructure of the glass-ceramics showed that the randomly distributed phlogopite and hydroxylapatite phases were favorable to the machinability of the glass-ceramics. A mean bending strength of about 160-180 MPa and a fracture toughness parameter KIC of about 2.1-2.3 were determined for the glass-ceramics.

  15. A Method for Semi-quantitative Analysis of C-S-H Gel in a Blended Cement Paste

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    An amended method for accurate measuring the quantity of calcium silicate hydrate(C-S-H) in pure cement paste and blended cement paste by water adsorption was made, which based on R.A.Olson's method. Two improvements to this method, such as using C-S-H gel by hydro-thermal synthesis as standard sample and the stoichiometry of C-S-H gel is partitioned based on hydration time and the amount of mineral admixture. The result of C-S-H gel content in pure cement paste and blended cement paste is higher than by R.A.Olson's method.

  16. Evaluation of ovine milk clotting aptitude

    Directory of Open Access Journals (Sweden)

    A. Caroli

    2010-01-01

    Full Text Available A comparative study of the lactodynamographic parameters was carried out on ovine milk. Besides evaluating the repeatability and reproducibility of the analytical method, the influence of some variables such as the genetic type (three breeds, the kind of milk (whole or skimmed, and its concentration after reconstitution (12g or 20g /100 ml was evaluated. The working plan involved 6 laboratories for the final statistic analyses, by the use of freeze-dried milk samples (adequately reconstituted on the basis of established methods from Sardinia, Comisana, and Massese ewes. All the considered variability factors showed a highly significant effect (P<0.001 on the lactodynamographic parameters considered. In particular, Massese ewe milk showed the shortest curd speed (k20 and the best coagulum strength (a30 and a45, although clotting time (CT was the highest one. The same trend was registered for skimmed milk and for the most concentrated one (20g. Repeatability values within laboratories were 96% and 97% for CT and k20, lowering for a30 e a45, (respectively 87% and 85%. Much lower coefficients were found for the among laboratories reproducibility, ranging from a maximum of 58% for CT to a minimum of 18% for k20. The wide variability observed indicates that lactodynamographic parameters are comparable only within the same lab. Further investigation is needed to compare different labs in order to obtain more homogeneous results.

  17. Problems concerning ovine milk clotting aptitude

    Directory of Open Access Journals (Sweden)

    M. Martini

    2003-01-01

    Full Text Available A comparative study of the lactodynamographic parameters was carried out on ovine milk. Besides evaluating the repeatability and reproducibility of the analytical method, the influence of some variables such as the genetic type (three breeds, the kind of milk (whole or skimmed, and its concentration after reconstitution (12g or 20g /100 ml was evaluated. The working plan involved 6 laboratories for the final statistic analyses, by the use of freeze-dried milk samples (adequately reconstituted on the basis of established methods from Sardinia, Comisana, and Massese ewes. All the considered variability factors showed a highly significant effect (P<0.001 on the lactodynamographic parameters considered. In particular, Massese ewe milk showed the shortest curd speed (k20 and the best coagulum strength (a30 and a45, although clotting time (CT was the highest one. The same trend was registered for skimmed milk and for the most concentrated one (20g. Repeatability values within laboratories were 96% and 97% for CT and k20, lowering for a30 e a45, (respectively 87% and 85%. Much lower coefficients were found for the among laboratories reproducibility, ranging from a maximum of 58% for CT to a minimum of 18% for k20. The wide variability observed indicates that lactodynamographic parameters are comparable only within the same lab. Further investigation is needed to compare different labs in order to obtain more homogeneous results.

  18. Quantitative evaluation of an image registration method for a NIPAM gel dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Yuan-Jen [Department of Management Information Systems, Central Taiwan University of Science and Technology, No. 666, Buzih Rd., Beitun District, Taichung City, Taiwan (R.O.C.) (China); Institute of Biomedical Engineering and Materials Science, Central Taiwan University of Science and Technology, No. 666, Buzih Rd., Beitun District, Taichung City, Taiwan (R.O.C.) (China); Yao, Chun-Hsu [School of Chinese Medicine, China Medical University, Taichung, Taiwan (R.O.C.) (China); Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan (R.O.C.) (China); Department of Biomedical Informatics, Asia University, Taichung, Taiwan (R.O.C.) (China); Wu, Jay [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan (R.O.C.) (China); Hsieh, Bor-Tsung [Department of Biomedical Imaging and Radiological Sciences, Central Taiwan University of Science and Technology, Taichung, Taiwan (R.O.C.) (China); Tsang, Yuk-Wah [Department of Radiation Oncology, Ditmanson Medical Foundation Chiayi Christian Hospital, Chiayi, Taiwan (R.O.C.) (China); Chen, Chin-Hsing [Department of Management Information Systems, Central Taiwan University of Science and Technology, No. 666, Buzih Rd., Beitun District, Taichung City, Taiwan (R.O.C.) (China)

    2015-06-01

    One of the problems in obtaining quality results is image registration when a gel dosimeter is used in conjunction with optical computed tomography (CT). This study proposes a passive alignment mechanism to obtain a precisely measured dose map. A holder plate with two pin–hole pairs is placed on the gel container cap. These two pin–hole pairs attach the gel container to the vertical shaft and can be precisely aligned with the rotation center of the vertical shaft at any time. Accordingly, a better reconstructed image quality is obtained. After obtaining a precisely measured dose map, the scale invariant feature transform (SIFT)-flow algorithm is utilized as an image registration method to align the treatment plan software (TPS) image with the measured dose map image. The results show that the gamma pass rate for the single-field irradiation increases from 83.39% to 94.03% when the algorithm is applied. And the gamma pass rate for the five-field irradiation treatment plan increases from 87.36% to 94.34%. The translation, scaling, and rotation occurring in the dose map image constructed using an optical CT scanner are also aligned with those in the TPS image using the SIFT-flow algorithm. Accordingly, improved gamma comparison results and a higher gamma pass rate are obtained. - Highlights: • A passive alignment method for obtaining a precisely measured dose map is developed. • The SIFT-flow algorithm is adopted as an image registration method for the gel dosimeter. • The SIFT-flow algorithm increases the gamma pass rate from 83.39% to 94.03% for the single-field irradiation. • The SIFT-flow algorithm increases the gamma pass rate from 87.36% to 94.34% for the five-field irradiation. • The translation, scaling, and rotation in the measured dose map image are aligned with those in the TPS image using the SIFT-flow algorithm.

  19. Effect of Drug Loading Method on Drug Content and Drug Release from Calcium Pectinate Gel Beads

    OpenAIRE

    2010-01-01

    Drug-loaded calcium pectinate gel (CaPG) beads were prepared by either mixing, absorption, or swelling method. The effects of drug loading method as well as the drug loading factors (i.e., drug concentration, soaking time in drug solution, type of solvent) on drug content and drug release were investigated. The amount of drug uptake (i.e., drug content) into CaPG beads increased as the initial drug concentration increased and varied depending on the loading method. The in vitro release studie...

  20. Preparation of glucose oxidase electrode containing hydrophobic silica nanoparticles by the sol-gel method

    Institute of Scientific and Technical Information of China (English)

    张琳; 唐芳琼; 袁金锁; 江龙

    1995-01-01

    The influences of hydrophobic SiO2 nanoparticles and the contents of glucose oxidase(GOD)upon the response current of enzyme electrode have been investigated by using the sol-gel method,in whichpolyvinylbutyryl(PVB)was used as a matrix.The influenoe of enzymatic activity was measured byelectrochemical method.Experimental data demonstrated that hydrophobic SiO2 particles can immobilizeenzyme well,providing a good and simple method for preparing high quality GOD biosensor.The mechanismhas been discussed.

  1. A simple immunoblotting method after separation of proteins in agarose gel

    DEFF Research Database (Denmark)

    Koch, C; Skjødt, K; Laursen, I

    1985-01-01

    A simple and sensitive method for immunoblotting of proteins after separation in agarose gels is described. It involves transfer of proteins onto nitrocellulose paper simply by diffusion through pressure, a transfer which only takes about 10 min. By this method we have demonstrated the existence...... of multiple molecular forms of the complement factors C3 and factor B in serum from 2 species, man and chicken, after electrophoretic separation in agarose. We have also demonstrated the usefulness of the method for determining the isoelectric point of proteins after isoelectric focusing in agarose....

  2. Clot dissolution is better with ultrasound assisted thrombolysis for fresh clots with higher cholesterol content

    Science.gov (United States)

    Zhou, Yufeng; Sharma, Vijay Kumar; Murugappan, Kanna Suresh; Ahmad, Aftab

    2012-11-01

    Tissue plasminogen activator (tPA) remains the only drug for recanalization in acute ischemic stroke, and the dose is determined by the patient's body-weight. Properties of the blood clot as well as ultrasound exposure might affect the thrombolysis outcome. In this study, clot was prepared by mixing horse blood with CaCl2 solution and cholesterin up to 1.0 mg/ml. To simulate the aging effect serum was replaced by fresh blood periodically. 225 IU/ml of tPA was used to initiate lysis. Clot was exposed to continuous 2 MHz transcranial Doppler ultrasound at acoustic intensity of 340 mW/cm2. The weight of the blood clot increased with its age (from 37.28±2.87 mg at 2 hrs to 51.56±5.34 mg at 10 hrs, p < 0.05). Although no difference between clot-cholesterol levels and thrombolysis with ultrasound or tPA alone was found, combination of these modalities induced significant lysis in the clots with cholesterol levels of more than 0.5 mg/ml (clot-weight reduced by 41.68±2.3%) as compared to clots with normal cholesterol (30.60±4.10%; p < 0.05). Altogether, sonothrombolysis seems to work better in fresh thrombi with high-cholesterol levels.

  3. Imaging and Elastometry of Blood Clots Using Magnetomotive Optical Coherence Tomography and Labeled Platelets

    Science.gov (United States)

    Oldenburg, Amy L.; Wu, Gongting; Spivak, Dmitry; Tsui, Frank; Wolberg, Alisa S.; Fischer, Thomas H.

    2013-01-01

    Improved methods for imaging and assessment of vascular defects are needed for directing treatment of cardiovascular pathologies. In this paper, we employ magnetomotive optical coherence tomography (MMOCT) as a platform both to detect and to measure the elasticity of blood clots. Detection is enabled through the use of rehydrated, lyophilized platelets loaded with superparamagnetic iron oxides (SPIO-RL platelets) that are functional infusion agents that adhere to sites of vascular endothelial damage. Evidence suggests that the sensitivity for detection is improved over threefold by magnetic interactions between SPIOs inside RL platelets. Using the same MMOCT system, we show how elastometry of simulated clots, using resonant acoustic spectroscopy, is correlated with the fibrin content of the clot. Both methods are based upon magnetic actuation and phase-sensitive optical monitoring of nanoscale displacements using MMOCT, underscoring its utility as a broad-based platform to detect and measure the molecular structure and composition of blood clots. PMID:23833549

  4. Application of the Sol-Gel Method at the Fabrication of PLZT:Yb3+ Ceramics

    Directory of Open Access Journals (Sweden)

    Osińska K.

    2016-09-01

    Full Text Available The aim of presented study was to obtain the PLZT:Yb3+ ceramics. Nanopowders of itterbium doped PLZT materials were synthesized by the sol-gel method from high quality metaloorganic precursors, as lead (II acetate, lanthanum acetate, ytterbium acetate, zirconium (IV propoxide and titanium (IV propoxide. Anhydrous acetic acid and n-propyl alcohol were used as solvents, while acetyloacetone was added as stabilizer of hydrolysis reactions. Thermal evolution of the dried gels, before and after calcination, was studied by the simultaneous thermal analysis. The amorphous PLZT:Yb3+ gels were first calcined in the furnace at T = 850°C, and then mixed in the planetary ball mill. Additionally, the mean particle sizes were calculated by means of powder specific surface area measurements, based on the BET physical adsorption isotherm. Such obtained powders were subsequently pressed into pellets, and sintered by the free sintering method at temperature T = 1250°C / 6h. The morphology of fabricated PLZT:Yb3+ ceramic powders and samples was studied using Scanning Electron Microscopy. Chemical characterization of samples was carried on using the Energy-dispersive X-ray spectroscopy - EDS system. Studies provided detailed data concerning the relationships between doping and preparing conditions on the basic physical and chemical properties of obtained ceramic materials.

  5. Aqueous sulfomethylated melamine gel-forming compositions and methods of use

    Energy Technology Data Exchange (ETDEWEB)

    Meltz, C.N.; Guetzmacher, G.D.; Chang, P.W.

    1989-04-18

    A method is described for the selective modification of the permeability of the strata of a subterranean bydrocarbon-containing reservoir consisting of introducing into a well in, communication with the reservoir; an aqueous gel-forming composition, comprising a 1.0-60.0 weight percent sulfomethylated melamine polymer solution. The solution is prepared with a 1.0 molar equivalent of a malemine, reacted with 3.0-6.7 molar equivalents of formaldehyde or a 2-6 carbon atom containing dialdehyde; 0.25-1.25 molar equivalents of an alkali metal or ammonium salt of surfurous acid; and 0.01-1.5 molar equivalents of a gel-modifying agent.

  6. Synthesis of β-tricalcium phosphate using sol-gel self-propagating combustion method

    Institute of Scientific and Technical Information of China (English)

    Jun ZHANG; Jinwu GUO; Suqin LI; Bangcai SONG; Kaisheng YAO

    2008-01-01

    β-tricalcium phosphate (β-TCP) is a key com-ponent of natural bone like hydroxyapatite. Pure and uni-formly nanosized β-tricalcium phosphate powders were synthesized using a sol-gel self-propagating combustion method by using citric acid as a reductant and using fuel and nitrate as the oxidant. The thermal decomposition of nitrate-citrate xero-gel was studied by thermogravimetric-differential thermal analysis (TG/DTA) and the process mechanism of self-propagating combustion were discussed. The resulting powders calcined at 1023, 1173 and 1273 K were characterized by Ca/P ratio analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmis-sion electron microscopy (TEM). It was found that the as-prepared powders were pure β-tricalcium phosphate having regular porous surface very similar to coral.

  7. Preparation of nanocrystalline ferroelectric BaNb2O6 by citrate gel method

    Indian Academy of Sciences (India)

    S P Gaikwad; Violet Samuel; Renu Pasricha; V Ravi

    2005-04-01

    A gel was formed when a aqueous solution of BaCl2, NbF5 and citric acid in stoichiometric ratio is heated on a water bath. This gel on decomposition at 600°C yielded the nano crystallites of BaNb2O6, as confirmed by X-ray diffraction study (XRD). This is a much lower temperature as compared to that prepared by traditional solid state method (1000°C) as reported for the formation of BaNb2O6. Transmission electron microscopic (TEM) investigations revealed that the average particle size is 50 nm for the calcined powders. The room temperature dielectric constant at 1 kHz is found to be 1000. The ferroelectric hysteresis loop parameters of these samples were also studied.

  8. Comparison of a New and Rapid Method: Brucella Coombs Gel Test With Other Diagnostic Tests.

    Science.gov (United States)

    Kalem, Fatma; Ergün, Ayşe Gül; Durmaz, Süleyman; Doğan, Metin; Ertuğrul, Ömür; Gündem, Seval

    2016-09-01

    The aim of this study was to detect reliability of Brucella Coombs gel test (BCGT) by comparing with with ELISA (IgG + IgM), Standard agglutination test, and Brucella immunocapture agglutination methods in serological diagnosis of brucellosis. Brucella Coombs gel test (BCGT), Brucella ELISA (IgG + IgM), Standard agglutination test, and Brucella immunocapture agglutination tests of 78 patients with presumptive diagnosis of brucellosis which were sent to Microbiology Laboratory of Konya Numune Hospital from various regions of Konya were studied. Of 78 patients with ELISA IgG and IgM, STA, BICA and BCGT; 26, 21, 10, 12 and 12 were positive. When compared with BICA, the sensitivity and specifity of BCGT were 100% and 100%, respectively. According to results BCGT can be used as a diagnostic test in routine laboratories after more comprehensive studies in control groups and patients. © 2016 Wiley Periodicals, Inc.

  9. Versatile technique to functionalize optical microfibers via a modified sol-gel dip-coating method.

    Science.gov (United States)

    Xu, Z Y; Li, Y H; Wang, L J

    2014-01-01

    We present a convenient and versatile technique to functionalize microfibers by depositing sol-gel jackets via a modified dip-coating method. This was elucidated by gain-functionalizing microfibers with erbium-ytterbium codoped silica sol-gel jackets. For a 4.5-cm-long coated microfiber, an internal gain of 1.8 dB and a net gain of 0.8 dB for a 1550 nm signal were observed, when combing together the gain of the doped jackets and low loss of microfibers. With benefits of convenience and versatility, this technique can be used for functionalizing microfibers with jackets showing gains in other spectral ranges, high nonlinearity, high sensitivity, and many other functions.

  10. Synthesis of Nanocrystalline La1-xSrxCrO3 by Sol-Gel Method

    Institute of Scientific and Technical Information of China (English)

    Ao Qing; Zhao Xinming; Li Dehui; Sun Liangcheng

    2004-01-01

    The nanocrystalline La1-xSrxCrO3 was prepared by sol-gel method using La( NO3 )3 · 6H2O, Sr( NO3 )2 and respectively. The phase transformation from dry-gel to crystal was investigated by means of TG, DSC and XRD. Influences of temperature and Sr quantity on particle-diameters were observed by HREM. The experimental results show that the best calcined temperature is near 800 ℃. The particle-diameters decrease with the increase of Sr quantity. The chromite phase formed continuously during crystallization process, which is mainly composed of four steps: ( 1 ) Carbonates first formed by decomposing metal citrates. (2) The decomposition of carbonates occurred metal oxides. (3) La0. 9Sr0.1 CrO4 were synthesized by the reaction of metal oxides. (4) Chromite phase formed lastly due to the decomposition of chromate phase.

  11. Preparation of ITO transparent conductive film by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-hua; REN Dong-yan

    2006-01-01

    The ITO transparent conductive films were prepared on substrate of quartz glass by sol-gel method. The raw materials were nitrate indium, acetylacetone and the dopant of anhydrous chloride (SnCl4). The process from gel to crystalline film and the microstructure of the films were investigated by DTA-TG, XRD and SEM. The influence of preparation processes on the electricity performance of the films was also studied by four-probe apparatus. The results show that the crystallization process of ITO xerogel completes when the heat treatment temperature reaches 600 ℃. The ITO films possesses on vesicular structures accumulated by spherical particles, and both heat treatment temperature and cooling rate have important effects on the resistivity ofITO films.

  12. Ozonation and sol-gel method to obtain Cu/Cu O nanoparticles from cyanidation wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Soria A, M. J.; Puente S, D. M.; Carrillo P, F. R. [Universidad Autonoma de Coahuila, Facultad de Metalurgia, Carretera 57 Km 4.5, 25710 Monclova, Coahuila (Mexico); Garcia C, L. A. [Centro de Investigacion en Quimica Aplicada, Blvd. Enrique Reyna No. 140, Col. Los Pinos, 25253 Saltillo, Coahuila (Mexico); Velazquez S, J., E-mail: frrcarrillo@yahoo.com.mx [University of Texas at San Antonio, Department of Physics and Astronomy, San Antonio TX 78249 (United States)

    2015-07-01

    The extraction process of gold and silver by cyanidation generates large amounts of effluent which also contain contaminants such as cyanide and significant metal values such as copper. This paper presents the results of the removal and recovery of copper from ozonation treatment of a residual aqueous cyanide. The residual solution was treated by ozonation-precipitation to obtain a precipitate of copper. From this, copper nano composites obtained by Pechini modified sol-gel method were obtained. The compounds obtained were characterized by X-ray diffraction, showing a dependence of the type of compounds formed over time of ozonation and heat treatment of the gel. The particle size was measured by scanning electron microscopy and calculated by the Scherrer equation, being between 50 and 120 nm. (Author)

  13. Study of NiCuZn ferrite powders and films prepared by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    Gao Liang-Qiu; Yu Guo-Jian; Wang Ying; Wei Fu-Lin

    2011-01-01

    This paper reports that a series of NiCuZn ferrite powders and films are prepared by using sol-gel method. The effects of raw material composition and the calcinate temperature on magnetic properties of them are investigated. The NiCuZn ferrite powders are prepared by the self-propagating high-temperature synthesis method and subsequently heated at 700 ℃~1000 ℃. The results show that NiCuZn ferrite powders with single spinel phase can be formed after heat-treating at 750 ℃. Powders obtained from Nio.4Cuo.2Zno.4Fe1.9O4 gel have better magnetic properties than those from gels with other composition. After heat-treating at 900 ℃ for 3 h, coercivity Hc and saturation magnetization Ms are 9.7 Oe (1 Oe = 80 A/m) and 72.4 emu/g, respectively. Different from the powders, NiCuZn films produced on Si (100) from the Ni0.4Cu0.2Zn0.4Fe2O4 gel formed at room temperature possess high properties. When heat-treating condition is around 600 ℃ for 6 min, samples with low Hc and high Ms will be obtained. The minimal Hc is 16.7 Oe and Ms is about 300 emu/cm3. In comparison with the films prepared through long-time heat treating, the films prepared through short heat-treating time exhibits better soft magnetic properties.

  14. Mesoscopic Modeling of Blood Clotting: Coagulation Cascade and Platelets Adhesion

    Science.gov (United States)

    Yazdani, Alireza; Li, Zhen; Karniadakis, George

    2015-11-01

    The process of clot formation and growth at a site on a blood vessel wall involve a number of multi-scale simultaneous processes including: multiple chemical reactions in the coagulation cascade, species transport and flow. To model these processes we have incorporated advection-diffusion-reaction (ADR) of multiple species into an extended version of Dissipative Particle Dynamics (DPD) method which is considered as a coarse-grained Molecular Dynamics method. At the continuum level this is equivalent to the Navier-Stokes equation plus one advection-diffusion equation for each specie. The chemistry of clot formation is now understood to be determined by mechanisms involving reactions among many species in dilute solution, where reaction rate constants and species diffusion coefficients in plasma are known. The role of blood particulates, i.e. red cells and platelets, in the clotting process is studied by including them separately and together in the simulations. An agonist-induced platelet activation mechanism is presented, while platelets adhesive dynamics based on a stochastic bond formation/dissociation process is included in the model.

  15. Sol–gel method as a way of carbonyl iron powder surface modification for interaction improvement

    Energy Technology Data Exchange (ETDEWEB)

    Małecki, P., E-mail: pawel.malecki@pwr.edu.pl [Polymer Engineering and Technology Division, W-3, Wrocław University of Technology, Smoluchowskiego 25, 50 370 Wrocław (Poland); Kolman, K.; Pigłowski, J. [Polymer Engineering and Technology Division, W-3, Wrocław University of Technology, Smoluchowskiego 25, 50 370 Wrocław (Poland); Kaleta, J. [Department of Mechanics, Materials Science and Engineering, W-10, Wrocław University of Technology, Smoluchowskiego 25, 50-370 Wrocław (Poland); Krzak, J., E-mail: justyna.krzak@pwr.edu.pl [Department of Mechanics, Materials Science and Engineering, W-10, Wrocław University of Technology, Smoluchowskiego 25, 50-370 Wrocław (Poland)

    2015-03-15

    This article presents a method for modification of carbonyl iron particles’ surface (CIP), (d{sub 50}=4–9 µm) by silica coatings obtained using the sol–gel method. Reaction parameters were determined to obtain dry magnetic powder with homogeneous silica coatings without further processing and without any by-product in the solid or liquid phase. This approach is new among the commonly used methods of silica coating of iron particles. No attempt has been made to cover a carbonyl iron surface by silica in a waste-free method, up to date. In the current work two different silica core/shell structures were made by the sol–gel process, based on different silica precursors: tetraethoxy-silane (TEOS) and tetramethoxy-silane (TMOS). The dependence between the synthesis procedure and thickness of silica shell covering carbonyl iron particles has been described. Surface morphology of the modified magnetic particles and the coating thickness were characterized with the use of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Determination of the physicochemical structure of the obtained materials was performed by the energy-dispersive X-ray spectroscope (EDS), and the infrared technique (IR). The surface composition was analyzed using X-ray photoelectron spectroscopy (XPS). Additionally, distribution of particle size was measured using light microscopy. The new, efficient process of covering micro-size CIP with a nanometric silica layer was shown. Results of a performed analysis confirm the effectiveness of the presented method. - Highlights: • Proper covering CIP by sol–gel silica layer avoids agglomeration. • A new solid waste-free method of CIP coating is proposed. • Examination of the properties of modified CIP in depends on washing process. • Coatings on CIP particles doesn’t change the magnetic properties of particles.

  16. Sol-gel Method Synthesized Polyhedron SnO_2 Anode Material for Lithium Ion Battery

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Introduction Tin-based oxides will be promising anode materials for lithium ion batteries due to its high specific capacity, low potential platform, and safety[1]. Many methods have been applied to synthesize SnO2 materials of different morphologies, such as chemical vapor deposition, spray, sol-gel method[2]. Triblock copolymer poly (ethylene oxide)-block-poly (propylene oxide)-block-poly (ethane oxide) (P123) has been used as surfactant to prepare nano-crystalline tin oxide particles[3]. In this pap...

  17. Development of a piezo-cantilever transducer and measuring method for evaluation of a temperature-sensitive polymer gel membrane

    Science.gov (United States)

    Li, Fenlan; Jiang, Zhongwei

    2007-06-01

    This paper is concerned with the development of a cantilever transducer patched with a piezoelectric element for evaluating the characteristics of a temperature-sensitive polymer gel membrane. The transducer consists of an aluminum cantilever beam patched with a piezoelectric ceramic and a probe coated by a polymer gel membrane. The probe can be easily attached to the cantilever transducer with double-sided sticky tape. The piezo-cantilever transducer is first simulated with the aid of a finite element method and the relation between the natural frequency change of the transducer and the absorbed mass on the polymer gel membrane is obtained theoretically. For measuring the temperature characteristics of the polymer gel membrane, the experiments are conducted in liquid and out of liquid. The temperature-sensitive poly(N-isopropylacrylamide) gel membrane hydrophilic-hydrophobic characteristics can be explained clearly by the results. Furthermore, two kinds of membrane coating method were proposed. The results indicate that the coating gel membrane has a better effect than the pasted gel membrane. The results also show that the piezo-cantilever transducer has a potential application for detecting polymer gel membrane characteristics conveniently and accurately.

  18. Disinfection studies on TiO2 thin films prepared by a sol-gel method.

    Science.gov (United States)

    Kambala, Venkata Subba Rao; Naidu, Ravi

    2009-02-01

    Transparent anatase TiO2 nanometer thin films were prepared by dip-coating on soda-lime glass plates via the sol-gel method. The un-calcined and the calcined films were characterized by X-ray diffraction (XRD), AFM, Nano-indentation (hardness and Young's modulus), UV-vis spectrometry, thickness and hydrophilicity (contact angle measurements). The photocatalytic activity of the thin films was evaluated by performing disinfection studies on the Gram-negative microorganisms like Escherichia coli, and Staphylococcus Aureus, a Gram-positive organism. The photocatalytic activity for both groups of organisms was studied in saline and nutrient broth. The leakage of potassium from the bacteria was observed parallel to cell viability. The activity of the sol-gel prepared TiO2 thin films were compared under UV lamps and natural day light (ND) lamps with Degussa P-25 TiO2 thin films prepared on soda-lime glass using a polymer support and the commercial self-cleaning glass (SC). The sol-gel prepared thin films which were annealed at 450 degrees C, show highest photocatalytic activity, the slowest conversion rate from hydrophilic to a hydrophobic state, light-induced hydrophilicity, and also higher disinfection activities compared to P-25 films and commercial self-cleaning glass. The films also show excellent activities when continuously reused for more than a month.

  19. Quantitative evaluation of an image registration method for a NIPAM gel dosimeter

    Science.gov (United States)

    Chang, Yuan-Jen; Yao, Chun-Hsu; Wu, Jay; Hsieh, Bor-Tsung; Tsang, Yuk-Wah; Chen, Chin-Hsing

    2015-06-01

    One of the problems in obtaining quality results is image registration when a gel dosimeter is used in conjunction with optical computed tomography (CT). This study proposes a passive alignment mechanism to obtain a precisely measured dose map. A holder plate with two pin-hole pairs is placed on the gel container cap. These two pin-hole pairs attach the gel container to the vertical shaft and can be precisely aligned with the rotation center of the vertical shaft at any time. Accordingly, a better reconstructed image quality is obtained. After obtaining a precisely measured dose map, the scale invariant feature transform (SIFT)-flow algorithm is utilized as an image registration method to align the treatment plan software (TPS) image with the measured dose map image. The results show that the gamma pass rate for the single-field irradiation increases from 83.39% to 94.03% when the algorithm is applied. And the gamma pass rate for the five-field irradiation treatment plan increases from 87.36% to 94.34%. The translation, scaling, and rotation occurring in the dose map image constructed using an optical CT scanner are also aligned with those in the TPS image using the SIFT-flow algorithm. Accordingly, improved gamma comparison results and a higher gamma pass rate are obtained.

  20. Secondary Crystal Growth on a Cracked Hydrotalcite-Based Film Synthesized by the Sol-Gel Method.

    Science.gov (United States)

    Lee, Wooyoung; Lee, Chan Hyun; Lee, Ki Bong

    2016-05-02

    The sol-gel synthesis method is an attractive technology for the fabrication of ceramic films due to its preparation simplicity and ease of varying the metal composition. However, this technique presents some limitations in relation to the film thickness. Notably, when the film thickness exceeds the critical limit, large tensile stresses occur, resulting in a cracked morphology. In this study, a secondary crystal growth method was introduced as a post-treatment process for Mg/Al hydrotalcite-based films synthesized by the sol-gel method, which typically present a cracked morphology. The cracked hydrotalcite-based film was hydrothermally treated for the secondary growth of hydrotalcite crystals. In the resulting film, hydrotalcite grew with a vertical orientation, and the gaps formed during the sol-gel synthesis were filled with hydrotalcite after the crystal growth. The secondary crystal growth method provides a new solution for cracked ceramic films synthesized by the sol-gel method.

  1. Lithium Ferrite as the Cathode of the Electrochemical Power Sources: the Perspectives of Sol-gel Synthesis Method

    Directory of Open Access Journals (Sweden)

    O.M. Uhorchuk

    2015-06-01

    Full Text Available Synthesis of highly dispersed systems of lithium-ferrite oxide spinel, obtained by the low-temperature sol-gel method, with the subsequent auto combustion and the comparison of these systems’ characteristics with the analogous ones of the conventional ceramic method are performed. It is shown that the systems synthesized by solid-phase and sol-gel methods are the single phase structures with the space group P4332. The sol-gel method of auto combustion made it possible to increase the size of crystallites in more than 4 times and the specific area of the surface in 20 times. Obtained by sol-gel method lithium pentaferrit is suggested to be used as the cathode of lithium power sources.

  2. An effective placental cotyledons proteins extraction method for 2D gel electrophoresis.

    Science.gov (United States)

    Tan, Niu J; Daim, Leona D J; Jamil, Amilia A M; Mohtarrudin, Norhafizah; Thilakavathy, Karuppiah

    2017-03-01

    Effective protein extraction is essential especially in producing a well-resolved proteome on 2D gels. A well-resolved placental cotyledon proteome, with good reproducibility, have allowed researchers to study the proteins underlying the physiology and pathophysiology of pregnancy. The aim of this study is to determine the best protein extraction protocol for the extraction of protein from placental cotyledons tissues for a two-dimensional gel electrophoresis (2D-GE). Based on widely used protein extraction strategies, 12 different extraction methodologies were carefully selected, which included one chemical extraction, two mechanical extraction coupled protein precipitations, and nine chemical extraction coupled protein precipitations. Extracted proteins were resolved in a one-dimensional gel electrophoresis and 2D-GE; then, it was compared with set criteria: extraction efficacy, protein resolution, reproducibility, and recovery efficiency. Our results revealed that a better profile was obtained by chemical extraction in comparison to mechanical extraction. We further compared chemical extraction coupled protein precipitation methodologies, where the DNase/lithium chloride-dense sucrose homogenization coupled dichloromethane-methanol precipitation (DNase/LiCl-DSH-D/MPE) method showed good protein extraction efficiency. This, however, was carried out with the best protein resolution and proteome reproducibility on 2D-gels. DNase/LiCl-DSH-D/MPE was efficient in the extraction of proteins from placental cotyledons tissues. In addition, this methodology could hypothetically allow the protein extraction of any tissue that contains highly abundant lipid and glycogen. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. [Results of fibrin clot application for acceleration of regeneration of the damaged mandible in experiment].

    Science.gov (United States)

    Maĭborodin, I V; Kolesnikov, I S; Shevela, A I; Sheplev, B V; Drovosekov, M N; Toder, M S

    2011-01-01

    The processes of regeneration of the damaged rat bottom jaw bone after application of enriched thrombocytes a fibrin clot were studied by morphological and radiovisiographic methods. At a natural course of regeneration the artificial aperture of bone was filled with blood and there the blood clot was formed. After 1 week the separate bone islets of a young tissue occurred in bone defect. In 2-3 weeks the aperture in a bottom jaw bone was completely closed by a young bone tissue. After operation with filling of bone bottom jaw defect by fibrin clot there was no formation of a blood clot. Already after 1 week the bone tissue defect was filled by the merged islets of again generated bone. By second week after fibrin use the further formation of bone tissue in defect and formation of a bone callosity was noted.

  4. Blood clotting reactions on nanoscale phospholipid bilayers.

    Science.gov (United States)

    Morrissey, James H; Pureza, Vincent; Davis-Harrison, Rebecca L; Sligar, Stephen G; Ohkubo, Y Zenmei; Tajkhorshid, Emad

    2008-01-01

    Blood clotting reactions, such as those catalyzed by the tissue factor:factor VIIa complex (TF:FVIIa), assemble on membrane surfaces containing anionic phospholipids such as phosphatidylserine (PS). In fact, membrane binding is critical for the function of most of the steps in the blood clotting cascade. In spite of this, our understanding of how the membrane contributes to catalysis, or even how these proteins interact with phospholipids, is incomplete. Making matters more complicated, membranes containing mixtures of PS and neutral phospholipids are known to spontaneously form PS-rich membrane microdomains in the presence of plasma concentrations of calcium ions, and it is likely that blood-clotting proteases such as TF:FVIIa partition into these PS-rich microdomains. Unfortunately, little is known about how membrane microdomain composition influences the activity of blood-clotting proteases, which is typically not under experimental control even in "simple" model membranes. Our laboratories have developed and applied new technologies for studying membrane proteins to gain insights into how blood-clotting protease-cofactor pairs assemble and function on membrane surfaces. This includes using a novel, nanoscale bilayer system (Nanodiscs) that permits assembling blood-clotting protease-cofactor pairs on stable bilayers containing from 65 to 250 phospholipid molecules per leaflet. We have used this system to investigate how local (nanometer-scale) changes in phospholipid bilayer composition modulate TF:FVIIa activity. We have also used detailed molecular-dynamics simulations of nanoscale bilayers to provide atomic-scale predictions of how the membrane-binding domain of factor VIIa interacts with PS in membranes.

  5. Comparison of Different Protein Extraction Methods for Gel-Based Proteomic Analysis of Ganoderma spp.

    Science.gov (United States)

    Al-Obaidi, Jameel R; Saidi, Noor Baity; Usuldin, Siti Rokhiyah Ahmad; Hussin, Siti Nahdatul Isnaini Said; Yusoff, Noornabeela Md; Idris, Abu Seman

    2016-04-01

    Ganoderma species are a group of fungi that have the ability to degrade lignin polymers and cause severe diseases such as stem and root rot and can infect economically important plants and perennial crops such as oil palm, especially in tropical countries such as Malaysia. Unfortunately, very little is known about the complex interplay between oil palm and Ganoderma in the pathogenesis of the diseases. Proteomic technologies are simple yet powerful tools in comparing protein profile and have been widely used to study plant-fungus interaction. A critical step to perform a good proteome research is to establish a method that gives the best quality and a wide coverage of total proteins. Despite the availability of various protein extraction protocols from pathogenic fungi in the literature, no single extraction method was found suitable for all types of pathogenic fungi. To develop an optimized protein extraction protocol for 2-DE gel analysis of Ganoderma spp., three previously reported protein extraction protocols were compared: trichloroacetic acid, sucrose and phenol/ammonium acetate in methanol. The third method was found to give the most reproducible gels and highest protein concentration. Using the later method, a total of 10 protein spots (5 from each species) were successfully identified. Hence, the results from this study propose phenol/ammonium acetate in methanol as the most effective protein extraction method for 2-DE proteomic studies of Ganoderma spp.

  6. Magnetic and Electric Properties of Semiconduter Bismuth Tri Sulphide (Bi2S3 Grown by Gel Method

    Directory of Open Access Journals (Sweden)

    T.K. Patil

    2011-01-01

    Full Text Available In the present investigation, crystals of bismuth Tri Sulphide (Bi2S3 were grown by a simple gel technique using single diffusion method. The optimum growth conditions were established by varying various parameters such as pH of gel solution, gel concentration, gel setting time, concentration of reactant etc. Gel was prepared by mixing sodium meta silicate (Na2SiO35H2O, glacial acetic acid (CH3COOH and supernant bismuth chloride (BiCl3 at pH value 4.4 and transferred in glass tube of diameter 2.5 cm and 25 cm in length. The mouth of test tube was covered by cotton plug and kept it for the setting. After setting the gel, it was left for aging. After 13 days duration the second supernant H2S water gas solution was poured over the set gel by using pipette then it was kept undisturbed. After 72 hours of pouring the second supernatant, the small nucleation growth was observed at below the interface of gel. The good quality Orthorhombic or Rhombus Bi2S3 crystals were grown in 31 days. These grown crystals were characterized by Magnetic Susceptibility, Electrical Conductivity, EDAX and SEM.

  7. A comparison of protein extraction methods suitable for gel-based proteomic studies of aphid proteins.

    Science.gov (United States)

    Cilia, M; Fish, T; Yang, X; McLaughlin, M; Thannhauser, T W; Gray, S

    2009-09-01

    Protein extraction methods can vary widely in reproducibility and in representation of the total proteome, yet there are limited data comparing protein isolation methods. The methodical comparison of protein isolation methods is the first critical step for proteomic studies. To address this, we compared three methods for isolation, purification, and solubilization of insect proteins. The aphid Schizaphis graminum, an agricultural pest, was the source of insect tissue. Proteins were extracted using TCA in acetone (TCA-acetone), phenol, or multi-detergents in a chaotrope solution. Extracted proteins were solubilized in a multiple chaotrope solution and examined using 1-D and 2-D electrophoresis and compared directly using 2-D Difference Gel Electrophoresis (2-D DIGE). Mass spectrometry was used to identify proteins from each extraction type. We were unable to ascribe the differences in the proteins extracted to particular physical characteristics, cell location, or biological function. The TCA-acetone extraction yielded the greatest amount of protein from aphid tissues. Each extraction method isolated a unique subset of the aphid proteome. The TCA-acetone method was explored further for its quantitative reliability using 2-D DIGE. Principal component analysis showed that little of the variation in the data was a result of technical issues, thus demonstrating that the TCA-acetone extraction is a reliable method for preparing aphid proteins for a quantitative proteomics experiment. These data suggest that although the TCA-acetone method is a suitable method for quantitative aphid proteomics, a combination of extraction approaches is recommended for increasing proteome coverage when using gel-based separation techniques.

  8. A safe and efficient method to retrieve mesenchymal stem cells from three-dimensional fibrin gels.

    Science.gov (United States)

    Carrion, Bita; Janson, Isaac A; Kong, Yen P; Putnam, Andrew J

    2014-03-01

    Mesenchymal stem cells (MSCs) display multipotent characteristics that make them ideal for potential therapeutic applications. MSCs are typically cultured as monolayers on tissue culture plastic, but there is increasing evidence suggesting that they may lose their multipotency over time in vitro and eventually cease to retain any resemblance to in vivo resident MSCs. Three-dimensional (3D) culture systems that more closely recapitulate the physiological environment of MSCs and other cell types are increasingly explored for their capacity to support and maintain the cell phenotypes. In much of our own work, we have utilized fibrin, a natural protein-based material that serves as the provisional extracellular matrix during wound healing. Fibrin has proven to be useful in numerous tissue engineering applications and has been used clinically as a hemostatic material. Its rapid self-assembly driven by thrombin-mediated alteration of fibrinogen makes fibrin an attractive 3D substrate, in which cells can adhere, spread, proliferate, and undergo complex morphogenetic programs. However, there is a significant need for simple cost-effective methods to safely retrieve cells encapsulated within fibrin hydrogels to perform additional analyses or use the cells for therapy. Here, we present a safe and efficient protocol for the isolation of MSCs from 3D fibrin gels. The key ingredient of our successful extraction method is nattokinase, a serine protease of the subtilisin family that has a strong fibrinolytic activity. Our data show that MSCs recovered from 3D fibrin gels using nattokinase are not only viable but also retain their proliferative and multilineage potentials. Demonstrated for MSCs, this method can be readily adapted to retrieve any other cell type from 3D fibrin gel constructs for various applications, including expansion, bioassays, and in vivo implantation.

  9. Preparation of self-sustained film by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    曹冰; 朱从善

    1999-01-01

    Large size self-sustained film with considerable thickness ranging from 30 to 500 μm was prepared with sol-gel method by using dimethyldiethoxysilane/tetraethoxysilane composite alkoxide as precursor. The film exhibits good plasticity as well. Various factors that may influence the film properties were investigated. IR and AFM techniques were adopted to study the film structure and surface morphology. Gas chromatogram/mass spectrum technique was also adopted to characterize the network structure of the material through identification of different polymers formed during hydrolysis and condensation course.

  10. Characterization of ZnO Thin Films Doped with Natrium by Sol-Gel Method

    OpenAIRE

    gareso, paulus lobo; Syuhada, Nurnadiyah; Rauf, Nurlaela; Juarlin, Eko; Sugianto; Maddu, Akhirruddin

    2014-01-01

    This article will be presented in the 4Th International conference on Theoretical and applied Physics in Bali for 16-17 October 2014 The characterization of ZnO films doped with natrium by sol-gel spin coating method have been studied using the optical transmittance UV-Vis and X-ray diffraction (X-RD) measurements. The ZnO films were prepared using zinc acetate dehydrate (Zn(CH3COO)2.2H2O), ethanol, and diethanolamine (DEA) as the precursor, solvent, and stabilizer, respectively. For ZnO d...

  11. Thermal properties and water repellency of cotton fabric prepared through sol-gel method

    Directory of Open Access Journals (Sweden)

    Gu Jia-Li

    2016-01-01

    Full Text Available Cotton fabrics were treated by one-step sol-gel method. The pure silica hydrosol and phosphorus-doped hydrosol were prepared with the addition of a hydrophobic hexadecyltrimethoxysilane to decrease the surface energy of cotton fabric. The thermal properties and water repellency of treated cotton fabric were characterized by thermo-gravimetric analysis, micro combustion, limiting oxygen index, and contact angle measurement. The results showed that cotton fabric treated by phosphorus-doped silica hydrosol had excellent flame retardance, and the water repellence was apparently improved with the addition of hexadecyltrimethoxysilane.

  12. KINETICS OF GRAIN-GROWTH OF YTTRIUM ALUMINUM GARNET FIBERS PREPARED BY SOL-GEL METHOD

    Directory of Open Access Journals (Sweden)

    Tan H.

    2013-12-01

    Full Text Available The yttrium aluminum garnet (YAG long fibers were prepared by the sol-gel method using aluminum chloride, aluminum powder, yttrium oxide and acetic acid as raw materials. The grain growth law is given by Dn – D0n = Kt (D0 = initial grain size, D = average grain size at time t, n = grain growth exponent and K = reaction constant. The grain growth exponent and activation energy of YAG fibers are ≈ 3 and 200 kJ/mol, respectively. The grain-growth behaviors of YAG were influenced by experimental conditions such as raw materials, initial particle size, initial particle distribution, etc.

  13. Fabrication of inverted zinc oxide photonic crystal using sol-gel solution by spin coating method.

    Science.gov (United States)

    Huang, Kuo-Min; Ho, Chong-Lung; Chang, Heng-Jui; Wu, Meng-Chyi

    2013-01-01

    Inverted zinc oxide photonic crystal structures were fabricated from polystyrene sphere (PSS) template using the sol-gel solution of ZnO by spin-coating method. It is easily able to control and fabricate the photonic crystal structures using the self-organized PSS with a size of 193 nm. The inverted ZnO photonic crystal structures observed show the (111) tendency of the hexagonal compact arrangement formation. The resulting structures possess the photonic band gaps in the near-ultraviolet range and exhibit an enhanced photoluminescence spectrum. The technology can effectively increase the light output intensity or efficiency for the applications of optoelectronic devices.

  14. Preparation of lithium fast ionic conductor by sol-gel-hydrothermal method

    Institute of Scientific and Technical Information of China (English)

    Wang Qinghua; Wang Bengen; Xu Yan; Liu Hongyu

    2006-01-01

    The solid fast ionic conductor was synthesized by the sol-gel-hydrothermal method.The influences of the dispersion reagent,the alkalinity and the calcination temperature on the surface morphology of nanopowders,and the electric conductivity were discussed.When PEG 12000 was used as the dispersion reagent,the alkalinity was 1.0% and the calcination temperature was 550℃; the electric conductivity at ambience temperature of the inorganic nanopowder of lithium fast ionic conductor synthesized was 2.59 ±10-3 S·cm-1.

  15. Preparation and Characterization of Ordered Ladder Like Polyphenylsilsesquioxane via Two-step Sol-gel Method

    Institute of Scientific and Technical Information of China (English)

    FENG Yu-zhong; QI Sheng-li; LIU Jing-jing; WU Zhan-peng; YANG Xiao-ping; JIN Ri-guang; WU De-zhen

    2011-01-01

    Soluble and ordered ladder like polyphenylsilsesquioxane was synthesized by a two-step sol-gel method including hydrolysis and polycondensation. The procedure was monitored by Fourier transform infrared spectroscopy and the presence of the ladder like structure was confirmed by X-ray techniques. 29Si NMR analysis shows a very narrow half peak width(δ<4) at δ-78.866 of the main chain unit C6H5SiO3/2 of polyphenylsilsesquioxane, indicating that the polyphenylsilsesquioxane has ordered ladder like structures rather than the branched ones. The relationship between molecular weight and the time of polycondensation was also discussed.

  16. Luminescence properties of Lu2O3: Tb film prepared by Pechini sol-gel method

    Science.gov (United States)

    Shen, Siqing; Wang, Jian; Xu, Zhibin; Xie, Jianjun; Shi, Ying

    2011-02-01

    Uniform and crack free Tb3+ doped lutetium oxide (Lu2O3:Tb) films were prepared by Pechini sol-gel method combined with the spin-coating technique. The influence of the different substrate (monocrystalline silicon (111) and silica glass) and atmosphere (N2 and Air) on the luminescence properties of films was investigated. According to the emission spectra, we found that the luminous intensity was higher on silica glass substrate. Moreover, it was found that the luminous intensity calcined in N2 was higher almost twice as that calcined in air.

  17. ORGANIC SOL-GEL METHOD IN THE SYNTHESIS AND CHARACTERIZATION OF ZINC OXIDE NANOPARTICLES

    Directory of Open Access Journals (Sweden)

    Keanchuan Lee

    2014-01-01

    Full Text Available Nanosized Zinc Oxide (ZnO was synthesized using sol-gel method. The nanomaterials with structure were annealed at different temperatures ranging from 500 to 700°C which were chosen based on the Thermogravimetric (TGA Analysis. The structure and morphology were characterized by Powder X-Ray Diffraction (PXRD and Transmission Electron Microscope (TEM, respectively. The PXRD shows the increasing tendency in crystallite size when the annealing temperature increases and the hexagonal structure of ZnO. TEM further revealed the same tendency which the Zn NPs size increased with the annealing temperature.

  18. A control method to inspect the compositional authenticity of Minas Frescal cheese by gel electrophoresis.

    Science.gov (United States)

    Magenis, Renata B; Prudêncio, Elane S; Molognoni, Luciano; Daguer, Heitor

    2014-08-20

    This study introduces a qualitative method to inspect the compositional authenticity of white nonripened cheeses like Minas Frescal, a typical Brazilian cheese, especially when irregular replacement of milk by whey is suspected. A sodium dodecyl sulfate gel electrophoresis (SDS-PAGE) method, followed by image densitometry, was validated. Cheeses were freeze-dried to electrophoresis, and β-lactoglobulin (β-LG) was chosen as the adulteration marker. In gel trypsin digestion followed by matrix assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry provided its identification. Cheeses with a minimum of 14 mg·g(-1) of β-LG are considered to be adulterated. The method shows satisfactory precision with a detection limit of 7 mg·g(-1). Forty-two commercial samples from inspected establishments were then assessed and subjected to cluster analysis. Compliant and noncompliant groups were set with 24 (57%) authentic samples and 18 (43%) adulterated samples, respectively, showing that proper analytical monitoring is required to inhibit this practice.

  19. Designing antimicrobial bioactive glass materials with embedded metal ions synthesized by the sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Palza, Humberto, E-mail: hpalza@ing.uchile.cl [Departamento de Ingeniería Química y Biotecnología, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago (Chile); Escobar, Blanca; Bejarano, Julian [Departamento de Ingeniería Química y Biotecnología, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago (Chile); Bravo, Denisse [Departamento de Patología, Facultad de Odontología, Universidad de Chile, Santiago (Chile); Diaz-Dosque, Mario [Departamento de Ciencias Básicas y Comunitarias, Facultad de Odontología, Universidad de Chile, Santiago (Chile); Perez, Javier [Departamento de Ingeniería Química y Biotecnología, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago (Chile)

    2013-10-15

    Bioactive glasses (SiO{sub 2}–P{sub 2}O{sub 5}–CaO) having tailored concentrations of different biocide metal ions (copper or silver) were produced by the sol–gel method. All the particles release phosphorous ions when immersed in water and simulated body fluid (SBF). Moreover, a surface layer of polycrystalline hydroxy-carbonate apatite was formed on the particle surfaces after 10 day immersion in SBF as confirmed by X-ray diffraction and scanning electron microscopy (SEM) showing the bioactive materials. Samples with embedded either copper or silver ions were able to further release the biocide ions with a release rate that depends on the metal embedded and the dissolution medium: water or SBF. This biocide ion release from the samples explains the antimicrobial effect of our active particles against Escherichia coli DH5α ampicillin-resistant (Gram-negative) and Streptococcus mutans (Gram-positive) as determined by the Minimum Bactericidal Concentration (MBC) method. The antimicrobial behavior of the particles depends on the bacteria and the biocide ion used. Noteworthy, although samples with copper are able to release more metal ion than samples with silver, they present higher MBC showing the high effect of silver against these bacteria. - Highlights: • Copper and silver act as antimicrobial additives in bioactive glass materials. • Silver is more toxic than copper ions in these bioactive materials. • Sol–gel method allows the synthesis of antimicrobial bioactive materials.

  20. Preparation of calcium fluoroaluminosilicate glasses containing sodium and phosphorus by the nonhydrolytic sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Cestari, Alexandre; Bandeira, Lucimara C.; Calefi, Paulo S. [Universidade de Franca, Av. Dr. Armando Salles Oliveira 201, Pq. Universitario, 14404-600 Franca, SP (Brazil); Nassar, Eduardo J. [Universidade de Franca, Av. Dr. Armando Salles Oliveira 201, Pq. Universitario, 14404-600 Franca, SP (Brazil)], E-mail: ejnassar@unifran.br; Ciuffi, Katia J. [Universidade de Franca, Av. Dr. Armando Salles Oliveira 201, Pq. Universitario, 14404-600 Franca, SP (Brazil)

    2009-03-20

    Aluminum and silicon oxide-based inorganic matrices have been extensively studied because of their countless applications. Dental cements consist of aluminum and silicon-based amorphous polymeric materials containing fluoride, sodium, phosphorus and calcium, which are also good candidates for bone replacement. The nonhydrolytic sol-gel method has emerged as an alternative route for the preparation of these materials under milder conditions than those employed in traditional methods, such as oxide fusion. The main advantages of the nonhydrolytic sol-gel method include the use of low temperatures and the ready availability and easy purification of the precursors. Together, these factors have contributed to the production of highly pure materials with controlled porosity and nanometric particles. Dental restorations based on aluminosilicate matrices are known as glass ionomer cements. These materials have interesting physical and dental properties, mainly because they display anticariogenic activity and exhibit prolonged adhesiveness to the dental structure. The base of the ionomer is an aluminosilicate that is industrially synthesized by the fusion of SiO{sub 2}, Al{sub 2}O{sub 3}, AlF{sub 3}, CaF{sub 2}, NaF and AlPO{sub 4}, in various concentrations. The characterizations conducted in this study reveal that this ionomer displays interesting properties, so its use as a precursor of dental cement and a biomaterial for bone replacement is highly recommended.

  1. PREPARATION AND CHARACTERIZATION OF TIO2-SILICONE NANOCOMPOSITE OBTAINED BY SOL-GEL METHOD

    Directory of Open Access Journals (Sweden)

    KOIZHAIGANOVA Meruyert

    2015-05-01

    Full Text Available The sol-gel process is attractive for the nanocomposite preparation due to its unique advantages such as low temperature processing, high homogeneity of final products and its capability to generate materials with controlled surface properties. The preparation of TiO2-Silicone nanocomposite by sol–gel method, which is efficient at producing thin, transparent multi-component oxide layers, was considered due to its possible application as finishing coating on leather. In this study the preparation and characterization of TiO2-Silicone nanocomposite were investigated. TiO2-Silicone nanocomposite was prepared from titanium n-butoxide (TBO and tetraethoxysilane (TEOS catalyzed with acid. The chemical structure of the composite was evaluated by means of Raman spectroscopy. Atomic Force Microscopy (AFM was employed to characterize the surface properties of composite films. In summary, the colloidal TiO2–Silicone nanocomposite solution was successfully synthesized using the sol-gel method. The turbidity value of the TiO2–Silicone nanocomposite solution was 12.7 ntu. The TiO2–Silicone nanocomposite was mildly acidic with a pH value of 5.2. It was determined that the viscosity of the TiO2– Silicone nanocomposite solution was approximately equal to 1-3 mPa.s. The particles sizes were approximately 5.4 nm, with the coatings being approximately 0.06 µm in thickness. From the results obtained it was revealed that the TiO2-Silicone nanocomposite can be used as coating in leather fninshing process.

  2. Temperature-independent pectin gel method for aerobic plate count in dairy and nondairy food products: collaborative study.

    Science.gov (United States)

    Roth, J N

    1988-01-01

    Ten laboratories participated in a collaborative study to compare the pectin-based plate count (PC) Redigel method with the aerobic plate count and standard plate count agar-based standard methods for the estimation of total bacterial counts in 9 different nondairy food and dairy food products. The foods were cream, homogenized milk, raw milk, cheese, raw chicken, raw oysters, frozen broccoli, flour, and spices. Each laboratory analyzed 6 samples (3 sample pairs) of each food group. Counts obtained by the pectin-based plate count and agar-based plate count methods differed significantly (P less than 0.05) only for homogenized milk, where the pectin gel method resulted in higher counts. The actual counts were higher in the pectin gel method in 8 of the 9 food groups. The log means for pectin gel and agar-based media, respectively, for the 9 food groups were: cream 8.106 and 7.844; homogenized milk 8.642 and 8.231; raw milk 8.711 and 8.423; chicken 7.654 and 7.645; oysters 7.201 and 7.180; broccoli 7.102 and 6.798; cheese 8.045 and 8.055; flour 4.112 and 3.988; spice 5.379 and 5.314. The repeatability standard deviations favored the pectin gel method in 6 of the 9 foods tested. The reproducibility standard deviations favored the pectin gel method in 7 of the 9 foods tested. These results strongly support the suitability of the pectin gel method as an alternative to agar-based plate count and other methods for total bacterial counts in nondairy and dairy food products. The pectin gel method has been adopted official first action.

  3. Synthesis of titanates MTiO{sub 3} (M = Mn, Co, Ni) by the sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, J.; Tavizon, G.; Vicente, L. [UNAM, Mexico City (Mexico). Dept. de Fisica y Quimica Teorica; Viveros, T. [UAM-Iztapalapa, Mexico City (Mexico). Dept. de Ingenieria Quimica

    1996-12-31

    The titanates MTiO{sub 3} (M = Ni, Co, Mn) were prepared by a sol-gel method. The reaction between the metal solution and titanium butoxide leads to the formation of gels. The amorphous gels so obtained under different pH conditions, were calcined at temperatures between 750 C and 1,200 C to obtain in some cases high purity, crystalline MTiO{sub 3} powders. The characterization of the samples was done by X-ray powder diffraction, differential thermal analysis (DTA), thermal gravimetry (TG) and BET surface measurements.

  4. Blood flow measurements and clot detection with nearinfrared spectroscopy

    OpenAIRE

    Rossow, MJ; Gatto, R.; D'amico, E.; Mantulin, WW; Gratton, E

    2006-01-01

    Detecting impeded blood flow and locating the clot causing it is a major challenge in neurosurgery. We propose an instrument that uses near-infrared spectroscopy to simultaneously detect clots and measure blood flow. © 2006 Optical Society of America.

  5. Antimicrobial activity of thin solid films of silver doped hydroxyapatite prepared by sol-gel method.

    Science.gov (United States)

    Iconaru, Simona Liliana; Chapon, Patrick; Le Coustumer, Philippe; Predoi, Daniela

    2014-01-01

    In this work, the preparation and characterization of silver doped hydroxyapatite thin films were reported and their antimicrobial activity was characterized. Silver doped hydroxyapatite (Ag:HAp) thin films coatings substrate was prepared on commercially pure Si disks by sol-gel method. The silver doped hydroxyapatite thin films were characterized by various techniques such as Scanning electron microscopy (SEM) with energy Dispersive X-ray attachment (X-EDS), Fourier transform infrared spectroscopy (FT-IR), and glow discharge optical emission spectroscopy (GDOES). These techniques have permitted the structural and chemical characterisation of the silver doped hydroxyapatite thin films. The antimicrobial effect of the Ag:HAp thin films on Escherichia coli and Staphylococcus aureus bacteria was then investigated. This is the first study on the antimicrobial effect of Ag:HAp thin films obtained by sol-gel method. The results of this study have shown that the Ag:HAp thin films with x(Ag) = 0.5 are effective against E. coli and S. aureus after 24 h.

  6. Antimicrobial Activity of Thin Solid Films of Silver Doped Hydroxyapatite Prepared by Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    Simona Liliana Iconaru

    2014-01-01

    Full Text Available In this work, the preparation and characterization of silver doped hydroxyapatite thin films were reported and their antimicrobial activity was characterized. Silver doped hydroxyapatite (Ag:HAp thin films coatings substrate was prepared on commercially pure Si disks by sol-gel method. The silver doped hydroxyapatite thin films were characterized by various techniques such as Scanning electron microscopy (SEM with energy Dispersive X-ray attachment (X-EDS, Fourier transform infrared spectroscopy (FT-IR, and glow discharge optical emission spectroscopy (GDOES. These techniques have permitted the structural and chemical characterisation of the silver doped hydroxyapatite thin films. The antimicrobial effect of the Ag:HAp thin films on Escherichia coli and Staphylococcus aureus bacteria was then investigated. This is the first study on the antimicrobial effect of Ag:HAp thin films obtained by sol-gel method. The results of this study have shown that the Ag:HAp thin films with xAg=0.5 are effective against E. coli and S. aureus after 24 h.

  7. A Novel Universal Primer-Multiplex-PCR Method with Sequencing Gel Electrophoresis Analysis

    Science.gov (United States)

    Huang, Kunlun; Zhang, Nan; Yuan, Yanfang; Shang, Ying; Luo, Yunbo

    2012-01-01

    In this study, a novel universal primer-multiplex-PCR (UP-M-PCR) method adding a universal primer (UP) in the multiplex PCR reaction system was described. A universal adapter was designed in the 5′-end of each specific primer pairs which matched with the specific DNA sequences for each template and also used as the universal primer (UP). PCR products were analyzed on sequencing gel electrophoresis (SGE) which had the advantage of exhibiting extraordinary resolution. This method overcame the disadvantages rooted deeply in conventional multiplex PCR such as complex manipulation, lower sensitivity, self-inhibition and amplification disparity resulting from different primers, and it got a high specificity and had a low detection limit of 0.1 ng for single kind of crops when screening the presence of genetically modified (GM) crops in mixture samples. The novel developed multiplex PCR assay with sequencing gel electrophoresis analysis will be useful in many fields, such as verifying the GM status of a sample irrespective of the crop and GM trait and so on. PMID:22272223

  8. Characterizations of maghemite thin films prepared by a sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Lau, L. N., E-mail: lau7798@gmail.com; Ibrahim, N. B., E-mail: baayah@ukm.edu.my [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor. Malaysia (Malaysia)

    2015-09-25

    Iron is one of the abundant elements of Mother Nature and its compound, iron oxide is an interesting material to study since its discovery in the form of magnetite. It can exist in many phases such as hematite and maghemite, this unique nature has put it as a potential candidate in various applications. The aim of this work is to study the influence of different precursor concentrations on the microstructural and magnetic properties of iron oxide thin film. All samples were prepared via the sol-gel method followed by a spin coating technique on quartz substrates. Iron oxide films were confirmed as maghemite phase from X-ray diffraction patterns. The film morphology was examined by a field emission scanning electron microscope and it showed non-systematic value of average grain size and film thickness throughout the study. Hysteresis loop further confirmed that maghemite is a magnetic material when it was characterized by a vibrating sample magnetometer. The coercivity did not show any correlation with molarity. Nevertheless, it increased as the precursor concentration of the film increased due to the domain behaviour. In conclusion, maghemite thin films were successfully synthesized by the sol-gel method with different precursor concentrations in this work.

  9. Synthesis of hybrid chitosan/calcium aluminosilicate using a sol-gel method for optical applications

    Energy Technology Data Exchange (ETDEWEB)

    Elnahrawy, Amany Mohamed [Department of Solid State, Physics Division, National Research Center (NRC), Giza 12622, Cairo (Egypt); Kim, Yong Soo, E-mail: yskim2@ulsan.ac.kr [Department of Physics and Energy Harvest-Storage Research Center (EHSRC), University of Ulsan, Ulsan 44610 (Korea, Republic of); Ali, Ahmed I., E-mail: Ahmed_ali_2010@helwan.edu.eg [Department of Physics and Energy Harvest-Storage Research Center (EHSRC), University of Ulsan, Ulsan 44610 (Korea, Republic of); Basic Science Department, Faculty of Industrial Education & Technology, Helwan University, Cairo 11281 (Egypt)

    2016-08-15

    Hybrid chitosan (CS)/calcium aluminosilicate nanocomposites thin films and membranes were prepared using a sol–gel method with three different concentrations of Al{sub 2}O{sub 3} (5, 7 and 10 mol. %). The prepared nanocomposites were characterized by transmission electron microscopy, X-ray diffraction and Fourier Transform Infrared spectroscopy. The optical properties of the prepared samples were analyzed by UV/Vis spectrophotometry and photoluminescence (PL) spectroscopy. The optical parameters revealed an increase in both the refractive index and band gap of the nanocomposites with increasing Al concentration. In addition, the PL spectra revealed a blue shift that was consistent with an increase in the optical band gap. These results suggest that CS/calcium aluminosilicate in two different forms can be a good candidate for optical sensors applications. - Highlights: • We show a large specific surface area of hybrid CS/calcium aluminosilicate thin films and membranes using sol-gel method. • Inorganic SiO{sub 2}-based phase are perfectly embedded onto chitosan matrix has a reliable stability. • CS/calcium aluminosilicate could be usable for optical sensors, planar waveguide, and bio-sensing.

  10. Preparation of zirconia nanopowders in ultrasonic field by the sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiaoxi; Chen Ling; Li Bing; Li Lin [Inst. of Light Industry and Chemical Engineering, South China Univ. of Technology, Guangzhou (China)

    2005-07-01

    Zirconia nanopowders were prepared in the ultrasonic field by the sol-gel method and the sonochemical effect on the structure of zirconium hydroxide and the zirconia nanopowder properties were systematically investigated in this work. Ultrasound was introduced into the different stages of the synthesis of zirconia nanopowders in sol-gel reaction system, and zirconium hydroxides and the zirconia nanopowders with different properties were obtained. The results indicated that ultrasonic cavitation could not only disaggregate the agglomerates of zirconia colloidal particles but also reduce the amount of coordinated H{sub 2}O, free H{sub 2}O and free hydroxyl groups of the zirconium hydroxide colloidal particles, thus effectively preventing the formation of hard agglomerates in zirconia powders. Moreover, the effects of different ultrasonic output powers and treatment cycles on the structure and properties of ZrO{sub 2} nanopowders were studied by TEM, XRD and SAXS. Zirconia nanopowders with an extremely small crystallite size (10.3 nm) and a narrow size distribution were yielded with 520 W ultrasound for 6 treatment cycles on the formation period and 600 W ultrasound for 2 treatment cycles on the washing period. It is concluded that the ultrasonic field is a potential method for nanopowder preparation. (orig.)

  11. Identification of fibrin clot-bound plasma proteins

    NARCIS (Netherlands)

    S. Talens (Simone); F.W.G. Leebeek (Frank); J.A.A. Demmers (Jeroen); D.C. Rijken (Dingeman)

    2012-01-01

    textabstractSeveral proteins are known to bind to a fibrin network and to change clot properties or function. In this study we aimed to get an overview of fibrin clot-bound plasma proteins. A plasma clot was formed by adding thrombin, CaCl2 and aprotinin to citrated platelet-poor plasma and unbound

  12. Methods for characterizing convective cryoprobe heat transfer in ultrasound gel phantoms.

    Science.gov (United States)

    Etheridge, Michael L; Choi, Jeunghwan; Ramadhyani, Satish; Bischof, John C

    2013-02-01

    While cryosurgery has proven capable in treating of a variety of conditions, it has met with some resistance among physicians, in part due to shortcomings in the ability to predict treatment outcomes. Here we attempt to address several key issues related to predictive modeling by demonstrating methods for accurately characterizing heat transfer from cryoprobes, report temperature dependent thermal properties for ultrasound gel (a convenient tissue phantom) down to cryogenic temperatures, and demonstrate the ability of convective exchange heat transfer boundary conditions to accurately describe freezing in the case of single and multiple interacting cryoprobe(s). Temperature dependent changes in the specific heat and thermal conductivity for ultrasound gel are reported down to -150 °C for the first time here and these data were used to accurately describe freezing in ultrasound gel in subsequent modeling. Freezing around a single and two interacting cryoprobe(s) was characterized in the ultrasound gel phantom by mapping the temperature in and around the "iceball" with carefully placed thermocouple arrays. These experimental data were fit with finite-element modeling in COMSOL Multiphysics, which was used to investigate the sensitivity and effectiveness of convective boundary conditions in describing heat transfer from the cryoprobes. Heat transfer at the probe tip was described in terms of a convective coefficient and the cryogen temperature. While model accuracy depended strongly on spatial (i.e., along the exchange surface) variation in the convective coefficient, it was much less sensitive to spatial and transient variations in the cryogen temperature parameter. The optimized fit, convective exchange conditions for the single-probe case also provided close agreement with the experimental data for the case of two interacting cryoprobes, suggesting that this basic characterization and modeling approach can be extended to accurately describe more complicated

  13. Limitations of using synthetic blood clots for measuring in vitro clot capture efficiency of inferior vena cava filters

    Directory of Open Access Journals (Sweden)

    Robinson RA

    2013-05-01

    Full Text Available Ronald A Robinson, Luke H Herbertson, Srilekha Sarkar Das, Richard A Malinauskas, William F Pritchard, Laurence W GrossmanOffice of Science and Engineering Laboratories, Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, MD, USAAbstract: The purpose of this study was first to evaluate the clot capture efficiency and capture location of six currently-marketed vena cava filters in a physiological venous flow loop, using synthetic polyacrylamide hydrogel clots, which were intended to simulate actual blood clots. After observing a measured anomaly for one of the test filters, we redirected the focus of the study to identify the cause of poor clot capture performance for large synthetic hydrogel clots. We hypothesized that the uncharacteristic low clot capture efficiency observed when testing the outlying filter can be attributed to the inadvertent use of dense, stiff synthetic hydrogel clots, and not as a result of the filter design or filter orientation. To study this issue, sheep blood clots and polyacrylamide (PA synthetic clots were injected into a mock venous flow loop containing a clinical inferior vena cava (IVC filter, and their captures were observed. Testing was performed with clots of various diameters (3.2, 4.8, and 6.4 mm, length-to-diameter ratios (1:1, 3:1, 10:1, and stiffness. By adjusting the chemical formulation, PA clots were fabricated to be soft, moderately stiff, or stiff with elastic moduli of 805 ± 2, 1696 ± 10 and 3295 ± 37 Pa, respectively. In comparison, the elastic moduli for freshly prepared sheep blood clots were 1690 ± 360 Pa. The outlying filter had a design that was characterized by peripheral gaps (up to 14 mm between its wire struts. While a low clot capture rate was observed using large, stiff synthetic clots, the filter effectively captured similarly sized sheep blood clots and soft PA clots. Because the stiffer synthetic clots remained straight when approaching the

  14. Characterization of Rod-like High-purity Fluorapatite Nanopowders Obtained by Sol-gel Method

    Directory of Open Access Journals (Sweden)

    Nasrin Sasani

    2013-12-01

    Full Text Available high purity fluorapatite (FA with rod-like and spherical-like morphology was synthesized via sol-gel method. Chemical characterization of FA powders was done by XRD and FTIR analyses. Crystallite samples were calculated using Scherer method. Morphology of FA powders was investigated with TEM and SEM images. The results revealed that increasing the time of hydrolysis of phosphate sols significantly decreased the gelation time of FA sols. Also, mixing temperature of P and Ca sols affects the gelation time of samples and increasing pH decreases the gelation time of FA sols. Morphological and chemical characterization of samples showed that the FA powders have high purity and rod-like and spherical-like morphology.

  15. Synthesis of iron doped titanium dioxide by sol-gel method for magnetic applications

    Directory of Open Access Journals (Sweden)

    Karen Oganisian

    2015-03-01

    Full Text Available In this paper magnetic properties of six TiO2 powders doped with 1, 5 and 10 mol% Fe and prepared by sol-gel method in two different ways were analysed. The size of the obtained TiO2:Fe particles was in the range 200–350 nm as it was confirmed by SEM and AFM techniques. The magnetization of nanopowders was measured as a function of temperature (1.8–300 K and applied magnetic field. The samples with low Fe content manifest superparamagnetic dependence of magnetization. Whereas, the other compounds exhibit the paramagnetic behaviour with the negative Curie temperature, that suggests the antiferromagnetic ordering. Mass susceptibility decreased with the increase of Fe content as an effect of reduction of the mobility and number of charge carriers. The measurements showed that magnetic properties are correlated much stronger with the synthesis method than with the grain size.

  16. Gel electrophoretic methods for the analysis of biosimilar pharmaceuticals using the example of recombinant erythropoietin.

    Science.gov (United States)

    Reichel, Christian; Thevis, Mario

    2013-03-01

    Due to their versatility and cost-effectiveness, gel electrophoretic methods provide an important set of tools for the analysis of therapeutic proteins. As an increasing number of biosimilar pharmaceuticals are entering the market, techniques are required that allow reliable demonstration of comparability of these products with the reference products. Isoelectric focusing, SDS-PAGE, native PAGE and 2D electrophoresis (2D-PAGE) have been frequently applied for this purpose. Supplementary techniques are fluorophore-assisted carbohydrate electrophoresis and sarcosyl-PAGE. Of additional importance is the comparison of recombinant with endogenously synthesized glycoproteins. Reagent array analysis combined with SDS-PAGE and western blotting proved especially useful for this purpose. As an example for the application of these methods, the analysis of recombinant originator erythropoietins and some of their biosimilar counterparts is described.

  17. Mesoporous Silica Materials Synthesized via Sol-Gel Methods Modified with Ionic Liquid and Surfactant Molecules

    Institute of Scientific and Technical Information of China (English)

    Cun-ying Xu; Ru-lan Tang; Yi-xin Hu; Peng-xiang Zhang

    2008-01-01

    Mesoporous silica materials were synthesized via a sol-gel method employing a room temperature ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate, [bmim][BF4]) as a new solvent medium and further modified with surfactant (hexadecyl-trimethyl-ammonium bromide, CTAB) as a pore templating material. The synthesized samples were characterized by the transmission electron microscopy, X-ray diffraction, and N2 adsorption-desorption techniques. The results indicated that the mesoporous silica synthesized by using [bmim][BF4] and CTAB as mixed templates showed better mesostructural order and smaller pore size, compared with mesoporous silica materials synthesized by using single [bmim][BF4]as template under the same conditions. This indicates that the presence of surfactant can affect the microstructures of silica prepared by the present synthesis method.

  18. Fabrication and properties of nanocrystalline zinc oxide thin film prepared by sol-gel method

    Directory of Open Access Journals (Sweden)

    Sumetha Suwanboon

    2008-01-01

    Full Text Available Zinc oxide (ZnO thin films were prepared on glass substrate by sol-gel dip-coating method. The structural properties were investigated by x-ray diffraction (XRD method and atomic force microscope (AFM. The optical properties were measured by UV-Vis spectrophotometer. The XRD patterns showed that the films formed preferred orientation along c-axis which increased as a function of polyvinyl pyrrolidone (PVP concentration. The films gave the crystallite size of 15-18 nm calculated by Scherrer’s formula and grain size of 48-70 nm measured by AFM at different PVP concentrations. The direct optical band gap of the films was in the range of 3.80-4.08 eV.

  19. Characterization and EXAFS Studies of Cobalt Synthesized by sol-gel auto Combustion Method

    Science.gov (United States)

    Mishra, Ashutosh; Singh, Priya; Ninama, Samrath

    2016-10-01

    The Co-Ni ferrites with general formula NiXCo1-XFe2O4 (where X=0.0, 0.1, 0.15, 2, 0.4) were prepared by Sol-gel auto combustion method. X-ray, FTIR and EXAFS measurement were carried out. Extended X ray Absorption Fine Structure (EXAFS) spectra have been recorded at the K-edge of Fe using the Dispersive EXAFS (DEXAFS) beam line-8 Indus-2 synchrotron radiation source RRCAT, Indore, India. The EXAFS data have been analysed using the computer softer Athena. These have been used to determine the Bond length in these ferrites with help of four different methods, namely, Levy's, Lytle's and Lytle, Sayers and stern's (LSS).

  20. Synthesis of potassium sodium niobate powders using an EDTA/citrate complexing sol-gel method

    Institute of Scientific and Technical Information of China (English)

    Yang Cao; Kongjun Zhu; Hongjuan Zheng; Jinhao Qiu; Honghui Gu

    2012-01-01

    Potassium sodium niobate (KNN) powders were synthesized by a modified sol-gel method,using as starting chemicals potassium carbonate,sodium carbonate,and niobium hydroxide,and,as esterification and chelating agents,respectively,ethylene glycol (EG) and ethylene diamine tetraacetic acid (EDTA)/citrate.The effects of citric acid (CA),EG,and EDTA on the stability of the precursor sol were systemically investigated.The powders and gels were characterized by X-ray diffraction,scanning electron microscopy,Fourier transform infrared spectroscopy,and thermogravimetric analysis-differential scanning calorimetry (TGA-DSC).The results indicated that a stable precursor sol was formed when n(CA)∶n(Mn+)=3∶1,n(EDTA)∶n(NH4OH) =1∶3.5,and n(CA)∶n(EG) =1∶2.The xerogel was calcined at 500-950 ℃ to prepare the KNN powder.Pure KNN perovskite phase with a cube-like structure was synthesized at 850 ℃ from the precursor sol for a K/Na molar ratio of 1.2.The formation mechanism of the KNN perovskite phase was also discussed.

  1. Fabrication of optical chemical ammonia sensors using anodized alumina supports and sol-gel method.

    Science.gov (United States)

    Markovics, Akos; Kovács, Barna

    2013-05-15

    In this comparative study, the fabrication and the sensing properties of various reflectometric optical ammonia gas sensors are described. In the first set of experiments the role of the support material was investigated on four different sensor membranes. Two of them were prepared by the adsorption of bromocresol green indicator on anodized aluminum plates. The applied anodizing voltages were 12 V and 24 V, which resulted in different dynamic ranges and response times for gaseous ammonia. The sol-gel method was used for the preparation of the other batch of sensors. These layers were coated on anodized aluminum plates (24 V) and on standard microscope cover glasses. In spite of the identical sensing chemistry, slightly different response times were measured merely because of the aluminum surface porosity. Gas molecules can remain entrapped in the pores, which results in delayed recovery time. On the other hand, the porous oxide film provides excellent adhesion, making the anodized aluminum an attractive support for the sol-gel layer.

  2. Hydroxyapatite, fluor-hydroxyapatite and fluorapatite produced via the sol-gel method. Optimisation, characterisation and rheology.

    Science.gov (United States)

    Tredwin, Christopher J; Young, Anne M; Georgiou, George; Shin, Song-Hee; Kim, Hae-Won; Knowles, Jonathan C

    2013-02-01

    Currently, most titanium implant coatings are made using hydroxyapatite and a plasma spraying technique. There are however limitations associated with plasma spraying processes including poor adherence, high porosity and cost. An alternative method utilising the sol-gel technique offers many potential advantages but is currently lacking research data for this application. It was the objective of this study to characterise and optimise the production of Hydroxyapatite (HA), fluorhydroxyapatite (FHA) and fluorapatite (FA) using a sol-gel technique and assess the rheological properties of these materials. HA, FHA and FA were synthesised by a sol-gel method. Calcium nitrate and triethylphosphite were used as precursors under an ethanol-water based solution. Different amounts of ammonium fluoride (NH4F) were incorporated for the preparation of the sol-gel derived FHA and FA. Optimisation of the chemistry and subsequent characterisation of the sol-gel derived materials was carried out using X-ray Diffraction (XRD) and Differential Thermal Analysis (DTA). Rheology of the sol-gels was investigated using a viscometer and contact angle measurement. A protocol was established that allowed synthesis of HA, FHA and FA that were at least 99% phase pure. The more fluoride incorporated into the apatite structure; the lower the crystallisation temperature, the smaller the unit cell size (changes in the a-axis), the higher the viscosity and contact angle of the sol-gel derived apatite. A technique has been developed for the production of HA, FHA and FA by the sol-gel technique. Increasing fluoride substitution in the apatite structure alters the potential coating properties. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  3. Formulation and Performance of Novel Energetic Nanocomposites and Gas Generators Prepared by Sol-Gel Methods

    Energy Technology Data Exchange (ETDEWEB)

    Clapsaddle, B J; Zhao, L; Prentice, D; Pantoya, M L; Gash, A E; Satcher Jr., J H; Shea, K J; Simpson, R L

    2005-03-24

    In the field of composite energetic materials, properties such as ingredient distribution, particle size, and morphology affect both sensitivity and performance. Since the reaction kinetics of composite energetic materials are typically controlled by the mass transport rates between reactants, one would anticipate new and potentially exceptional performance from energetic nanocomposites. We have developed a new method of making nanostructured energetic materials, specifically explosives, propellants, and pyrotechnics, using sol-gel chemistry. A novel sol-gel approach has proven successful in preparing nanostructured metal oxide materials. By introducing a fuel metal, such as aluminum, into the nanostructured metal oxide matrix, energetic materials based on thermite reactions can be fabricated. Two of the metal oxides are tungsten trioxide and iron(III) oxide, both of which are of interest in the field of energetic materials. Due to the versatility of the preparation method, binary oxidizing phases can also be prepared, thus enabling a potential means of controlling the energetic properties of the subsequent nanocomposites. Furthermore, organic additives can also be easily introduced into the nanocomposites for the production of nanostructured gas generators. The resulting nanoscale distribution of all the ingredients displays energetic properties not seen in its micro-scale counterparts due to the expected increase of mass transport rates between the reactants. The unique synthesis methodology, formulations, and performance of these materials will be presented. The degree of control over the burning rate of these nanocomposites afforded by the compositional variation of a binary oxidizing phase will also be discussed. These energetic nanocomposites have the potential for releasing controlled amounts of energy at a controlled rate. Due to the versatility of the synthesis method, a large number of compositions and physical properties can be achieved, resulting in

  4. Brillouin spectroscopy of clotting dynamics in a model system

    Science.gov (United States)

    Bustamante-Lopez, Sandra C.; Traverso, Andrew J.; Yakovlev, Vladislav V.; Meissner, Kenith E.

    2016-02-01

    Keys to successful treatment of disease include early diagnosis and timely treatment. It is hypothesized that early clotting events may contribute to a pro-thrombotic state that exacerbates atherothrombotic vascular disease. Brillouin spectroscopy involves inelastic coupling of light with phonons and enables viscoelastic characterization of samples at the microscale. In this work, we apply Brillouin spectroscopy to a model fibrinogen-thrombin clotting system with the goal of measuring clotting dynamics at the microscale and providing characterization that is not possible with standard rheometric techniques. Here, the clotting dynamics of the model clotting system are measured at various fibrinogen and thrombin concentrations.

  5. Development of gel-filter method for high enrichment of low-molecular weight proteins from serum.

    Directory of Open Access Journals (Sweden)

    Lingsheng Chen

    Full Text Available The human serum proteome has been extensively screened for biomarkers. However, the large dynamic range of protein concentrations in serum and the presence of highly abundant and large molecular weight proteins, make identification and detection changes in the amount of low-molecular weight proteins (LMW, molecular weight ≤ 30kDa difficult. Here, we developed a gel-filter method including four layers of different concentration of tricine SDS-PAGE-based gels to block high-molecular weight proteins and enrich LMW proteins. By utilizing this method, we identified 1,576 proteins (n = 2 from 10 μL serum. Among them, 559 (n = 2 proteins belonged to LMW proteins. Furthermore, this gel-filter method could identify 67.4% and 39.8% more LMW proteins than that in representative methods of glycine SDS-PAGE and optimized-DS, respectively. By utilizing SILAC-AQUA approach with labeled recombinant protein as internal standard, the recovery rate for GST spiked in serum during the treatment of gel-filter, optimized-DS, and ProteoMiner was 33.1 ± 0.01%, 18.7 ± 0.01% and 9.6 ± 0.03%, respectively. These results demonstrate that the gel-filter method offers a rapid, highly reproducible and efficient approach for screening biomarkers from serum through proteomic analyses.

  6. Nano crystals of Ni doped Zn O semiconductor by Sol-Gel combustion method

    Energy Technology Data Exchange (ETDEWEB)

    Carrero, A.; Sagredo, V. [Universidad de Los Andes, Departamento de Fisica, Laboratorio de Magnetismo, 5101 Merida (Venezuela, Bolivarian Republic of); Larionova, J., E-mail: aneelyc@gmail.com [Universite Montpellier II, 2 Place Eugene Bataillon, 34090 Montpellier (France)

    2016-11-01

    Nanoparticles of the system Zn{sub 0.95}O were prepared by sol-gel self - combustion method and a study of their structural, optical and magnetic properties were conducted. X-ray diffraction study shows a hexagonal wurtzite structure for the nano compound. The formation of the wurtzite structure in Ni doped Zn O was further confirmed by Fourier transform infra-red spectrometry. Transmission electron microscopy revealed an average size of 31 nm for the particles. Optical absorption spectra shows that the band energy of Zn{sub 0.95}Ni{sub 0.}9{sub 5}O powders is about 2.54 eV at room temperature. A study of the magnetic properties of the nano powders of Zn O: Ni, reveals paramagnetic behavior, with interaction ferromagnetic between particles. (Author)

  7. Preparation of Nanometer-structured TiO2 Thin Films by Sol-Gel Method

    Institute of Scientific and Technical Information of China (English)

    HE Feng; LI Qian-tao; HU Wang-kai; DENG Tao

    2002-01-01

    The transparent anatase TiO2 nanometer thin films were prepared by the sol-gel method on soda-lime glass. X-ray diffraction, thermal analysis and UV-visible spectrophotometer were used to analyze the formation of the phases. Only increasing the heat-treatment time, the average grain size has no obvious change. The mechanism of grain growth in TiO2 thin film is probably as follows: the grain of coating will become grain core later; TiO2 sol constantly deposited on the surface of TiO2 grain and formed membrane with increasing of coating cycle times; TiO2 grain in the film grow steadily.

  8. Effect of Annealing on the Properties of Vanadium Pentoxide Films Prepared by Sol-Gel Method

    Science.gov (United States)

    Liu, Yaqiang; Du, Xuelian; Liu, Xueqin

    2014-03-01

    The vanadium pentoxide (V2O5) films were obtained by using sol-gel procedure and then were annealed at different temperature in air. The effect of different annealing temperatures on the composition, the microstructure, the surface morphology and the optical properties of the films were characterized by methods such as by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and spectral transmittance. The results revealed that the film annealed at 150°C has amorphous structure and dense with a smooth surface and the films annealed at 300°C and 450°C have a polycrystalline V2O5 structure with preferred growth orientation along (001) planes, the c-axis and perpendicular to the silicon substrate surface. From the spectral transmittance we determined the absorption edge using the Tauc plot. The results indicated that optical bandgap of V2O5 thin films decreased with annealing temperature.

  9. Deposition of Co-doped TiO2 Thin Films by sol-gel method

    Science.gov (United States)

    Boutlala, A.; Bourfaa, F.; Mahtili, M.; Bouaballou, A.

    2016-03-01

    Cobalt doped TiO2 thin films have been prepared by sol-gel method onto glass substrate at room temperature. in this present work, we are interesting to study the effect of Cobalt doped TiO2 thin films.the concentration of Co was varied from 0 to 6%at .The obtained films have been annealed at 500°C for 2 hours. X-ray diffraction patterns showed that Co: TiO2 films are polycrystalline with a tetragonal anatase and orthorhombic brookite types structures. The surface morphologies of the TiO2 doped with cobalt thin films were evaluated by Atomic Force Microscopy (AFM). The optical properties were studied by mean of UV-visible and near infrared spectroscopy.The calculated optical band gap decreases from 3.30 to 2.96 eV with increasing Co doping.

  10. A novel sol-gel method for preparing favorable TiO2 thin film

    Science.gov (United States)

    Wang, Xiaoyi; Zhang, Dainan; Li, Jie; Zhong, Zhiyong; Jia, Lijun; Wen, Tianlong; Zhang, Huaiwu; Liao, Yulong

    2016-01-01

    Nanocrystalline TiO2 thin films were synthesized by the sol-gel spin-coating method with different variables. Tetrabutyl titanate (TBOT) proportion and C5H8O2: TBOT molar ratio were confirmed to be influential on the gelation time. X-ray diffraction analysis indicated that the samples presented rutile TiO2 phases, which is a basis for subsequent experiments. Scanning electron microscope results revealed that TiO2 thin films with homogeneous and compact surfaces were synthesized successfully when adding moderate TBOT. It was found the thickness of films could reach about 60 nm when sintered at 750 °C, and the influence of sintering temperature was also investigated.

  11. Low Temperature Synthesis And Characterization Of ZnTiO3 by Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    K.V. Rao

    2011-01-01

    Full Text Available ZnTiO3 nanoparticles were prepared by a modified sol-gel method at the low sintering temperature of 550 °C. Titanium tetra isopropoxide and Zinc acetate dihydrate (C4H10O6Zn(H2O2 materials were used as a source of titanium and zinc, respectively. The prepared nanopowders were characterized by means of X-ray diffraction (XRD, thermal gravimetric analysis (TGA, field emission Scanning electron microscope (FE-SEM and Raman spectroscopy. The XRD patterns and Raman spectra revealed that in the temperature range of 550 to 800 °C, ZnTiO3 is the only zinc titanate compound exists in the samples.

  12. TiO{sub 2} thin films prepared by sol - gel method

    Energy Technology Data Exchange (ETDEWEB)

    Suciu, R C; Indrea, E; Silipas, T D; Dreve, S; Rosu, M C [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania); Popescu, V; Popescu, G; Nascu, H I, E-mail: ramona.suciu@itim-cj.r [Technical University of Cluj-Napoca, Physics Department, 15 C Daicoviciu, 400020 Cluj-Napoca (Romania)

    2009-08-01

    There is a growing awareness that titania (TiO{sub 2}) and TiO{sub 2}-based oxide systems are the most promising candidates for the development of photoelectrodes for photoelectrochemical cell (PEC) for solar-hydrogen production. The PEC is equipped with a single photoelectrode (photoanode) and cathode, both of which are immersed in an aqueous electrolyte. In this work we present a sol-gel method to prepare TiO{sub 2} thin films on ITO using tetraisopropoxides of titanium, acetylacetone, 1-butanol and Tween 80 as surfactant. The films were deposited on ITO coated glass slides by spray pyrolysis. UV-VIS spectra and fluorescence measurements were made for the solutions and films. X-ray diffraction was used for structural investigations and the morphology of the film was studied by Scanning Electron Microscopy.

  13. TiO2 thin films prepared by sol - gel method

    Science.gov (United States)

    Suciu, R. C.; Indrea, E.; Silipas, T. D.; Dreve, S.; Rosu, M. C.; Popescu, V.; Popescu, G.; Nascu, H. I.

    2009-08-01

    There is a growing awareness that titania (TiO2) and TiO2-based oxide systems are the most promising candidates for the development of photoelectrodes for photoelectrochemical cell (PEC) for solar-hydrogen production [1]. The PEC is equipped with a single photoelectrode (photoanode) and cathode, both of which are immersed in an aqueous electrolyte. In this work we present a sol-gel method to prepare TiO2 thin films on ITO using tetraisopropoxides of titanium, acetylacetone, 1-butanol and Tween 80 as surfactant. The films were deposited on ITO coated glass slides by spray pyrolysis. UV-VIS spectra and fluorescence measurements were made for the solutions and films. X-ray diffraction was used for structural investigations and the morphology of the film was studied by Scanning Electron Microscopy.

  14. Preparation and Sinterability of Mn-Zn Ferrite Powders by Sol-Gel Method

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Mn-Zn spinel ferrites were synthesized by sol-gel method. Effects of calcined temperature on structure and particle size of MnZnFe2O4 were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD patterns indicate that the ultra fine Mn-Zn ferrite exhibits a spinel crystal structure. SEM images show that the powder fired at 900 ℃ for 2 h has an average diameter of 60~90 nm. The particle size becomes larger with the increasing of calcined temperature and the distribution of particle becomes even more homogeneous. Sintering behaviors of synthesized ferrite powders depend on the powder characteristics and high temperatures have induced the good crystallization of particles.

  15. Microbicidal activity of TiO2 nanoparticles synthesised by sol-gel method.

    Science.gov (United States)

    Priyanka, Karathan Parakkandi; Sukirtha, Thiruvangium Henry; Balakrishna, Kagalagodu Manjunthiah; Varghese, Thomas

    2016-04-01

    In this study, the authors investigated antimicrobial activity of TiO2 nanoparticles (NPs) synthesised by sol-gel method. As synthesised TiO2 NPs were characterised by X-ray diffraction, scanning electron microscopy and ultraviolet-visible absorption spectroscopy. The antimicrobial activity of calcined TiO2 nanoparticle samples was examined in day light on Gram positive bacteria (Staphylococcus aureus, Streptococcus pneumonia and Bacillus subtilis), Gram negative bacteria (Proteus vulgaris, Pseudomonas aeruginosa and Escherichia coli) and fungal test pathogen Candida albicans. The synthesised TiO2 NPs were found to be effective in visible light against Streptococcus pneumonia, Staphylococcus aureus, Proteus vulgaris, Pseudomonas aeruginosa and Candida albicans.

  16. The effect of Ni and Fe doping on YBCO powder prepared by sol gel method

    Directory of Open Access Journals (Sweden)

    F Saeb

    2009-08-01

    Full Text Available  We fabricated YBa2Cu3-xMxO7- d (M=Ni, Fe bulk samples, with stochiometric amount 0≤x≤0.045 by sol-gel method. The phase analysis and microstructure of specimens were examined by XRD and SEM. The electrical resistivity was measured using standard four probe technique for 77-300K. Investigation of XRD spectrum by MAUD shows Ni and Fe ions substitute in Cu(2 and Cu(1 site, respectively. Transition temperature decreases in 93-87K for Ni-doped samples and 93-92K for Fe-doped series. It seems that the suppression of superconductivity has no direct correlation with the magnetism of ions itself .

  17. Surface treatment of nickel substrate for the preparation of BSCCO film through sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Yang Huazhe, E-mail: hzyang@mail.cmu.edu.cn [Department of Biophysics, College of Basic Medical Science, China Medical University, Shenyang 110001 (China); Yu Xiaoming [Institute of Materials Physics and Chemistry, School of Sciences, Northeastern University, Shenyang 110819 (China); Ji Yang [Stomatology Department of the General Hospital of Shenyang Military Area Command, Shenyang, 110840 (China); Qi Yang, E-mail: qiyang@imp.neu.edu.cn [Institute of Materials Physics and Chemistry, School of Sciences, Northeastern University, Shenyang 110819 (China)

    2012-03-15

    A modified degreasing-oxidization process was devised and settled to treat the surface of nickel (Ni) substrates, and BSCCO films were prepared on the treated NiO/Ni substrates by sol-gel method. X-ray diffraction (XRD) and optical microscopy were adopted to clarify the function of different treatment on phase formation and wettability of NiO/Ni substrates. Differential thermal analysis and thermal gravimetry analysis were adopted to confirm the desirable heat treatment process. XRD and scanning electron microscopy were adopted to investigate the phase constituent and surface morphology of BSCCO films. Results demonstrate that both the surface wettability of the substrate to sol and the lattice matching between the substrate and BSCCO can be improved through the modified treatment, which are favorable for the preparation of BSCCO films.

  18. Study of optical characteristics of tin oxide thin film prepared by sol–gel method

    Indian Academy of Sciences (India)

    Sumanta Kumar Tripathy; Bhabani Prasad Hota; P V Rajeswari

    2013-12-01

    In this paper, we present details of preparation of tin oxide (SnO2) thin film by sol–gel process. The film was synthesized on a glass (Corning 7059) plate by dip coating method. Here, we used tin (II) chloride as precursor and methanol as solvent. Optical characteristics and physical properties like refractive index, absorption coefficient and thickness of thin film were calculated from the study of transmission spectrum (wavelength vs transmission curve) data given by UV/VIS Spectrophotometer. Effect of number of coatings on transmittance and refractive index was also examined. It was observed that refractive index decreases with the number of coating and transmission value was more than 80% at wavelength greater than 450 nm in all cases. Structural analysis was studied by XRD measurement by using diffractometer which confirms tetragonal rutile structure of SnO2. Surface morphology was analysed from SEM micrograph and change in morphology on number of coat was discussed.

  19. Structural, electrical and magnetic properties of Ni2+ substituted cobalt nanoferrite using sol-gel method

    Science.gov (United States)

    Blessington Selvadurai, A. Paul; Gazzali, P. M. Md.; Murugasen, C.; Pazhanivelu, V.; Murugaraj, R.; Chandrasekaran, G.

    2013-02-01

    Ni doped cobalt ferrite of chemical formula Ni(1-x)CoxFe2O4 with x values = 1, 0.5, 0 were prepared by using Poly Vinyl Alcohol (PVA) sol-gel method. The prepared samples were heat treated at 450°C for an hour and grounded to form fine powder. XRD of the powder sample confirms the formation of spinel ferrite phase. SEM and EDAX spectrum reveals the surface and chemical composition of the sample. FTIR spectra of the samples show the stretching vibration of the tetrahedral (ν1) and octahedral (ν2) bands of Fe-O bonds appearing at 600cm-1 and 424cm-1 respectively. Room temperature magnetic and electrical studies were done using VSM and LCZ meter to analyze their property respectively.

  20. Synthesis of indium tin oxide nanoparticles by a nonhydrolytic sol-gel method

    Directory of Open Access Journals (Sweden)

    Gabriel M. Silva

    2012-01-01

    Full Text Available Indium tin oxide nanoparticles were synthesized in two different sizes by a nonhydrolytic sol-gel method. These powders were then transformed into ITO via an intermediate metastable state at between 300 and 600 ºC. The presence of characteristic O-In-O and O-Sn-O bands at 480 and 670 cm-1 confirmed the formation of ITO. The X-ray diffraction patterns indicated the preferential formation of metastable hexagonal phase ITO (corundum type as opposed to cubic phase ITO when the reflux time was less than 3 h and the heat treatment temperature was below 600 ºC. Particle morphology and crystal size were examined by scanning electron microscopy.

  1. Photocatalytic and antibacterial activity of ZnO powders prepared via sol-gel method

    Directory of Open Access Journals (Sweden)

    Weerachai Sangchay

    2016-02-01

    Full Text Available We report on synthesis of ZnO powders via sol-gel method. The prepared powders were calcined at the temperature of 300, 500 and 700°C for 1 h with the heating rate of 10°C/min. The microstructures of the fabricated powders were characterized by SEM and XRD techniques, and the results show that all samples were the agglomeration and spherical shape and reveal only the wurtzite phase. The photocatalytic activities of the powders were also tested via the degradation of methylene blue (MB solution under UV irradiation. Finally, antibacterial activity efficiency was evaluated by the inactivation of E. coli. It was observed that higher calcined at the temperature gives better photocatalytic and antibacterial activity. With the highest calcined at the temperature investigated in this experiment (T700 condition the powders show photocatalytic and antibacterial activities of 80.06 and 99.00%, respectively.

  2. Preparation of PDMS-coated microspheres by sol-gel method for sorptive extraction of PAHs

    Institute of Scientific and Technical Information of China (English)

    Chang Guang Yang; Xiang Juan Ji; Xiao Zheng Lan

    2008-01-01

    In this paper, a novel SPME mode, PDMS-coated solid glass microspheres (SGMs), were prepared by sol-gel method. Using homemade thermal desorption unit coupled with CGC-FID, six PAHs as model analytes, the performance of the new mode was characterized. The new extractive phase exhibited high thermal stability and satisfactory extraction capability. The detection limits were 0.01-0.045 ng/mL, and the linearity was from 0.5 ng/mL to 96 ng/mL. The R.S.D.s of repeatability for retention time and peak area were all within 0.074% and 6.7%, respectively. The recoveries of the PAHs were 78-127% from the sarnples taken from river water.

  3. Characterization of Spin-on Dopant by Sol-gel Method

    Science.gov (United States)

    Kamil, S. Ahmad; Ibrahim, K.; Aziz, A. Abdul

    2008-05-01

    P-N junction is a basic building block for many important electron devices from as simple as a solar cell to very complicated integrated circuit. In this work, spin-on dopant (SOD) was used as the diffusion source in order to create p-n junction. SOD was prepared by using sol gel method. The spin-on dopant solution ingredients contain tetraethylorthosilicate (TEOS), isopropanol (IPA), distilled water (H2O), acetone and phosphoric acid (H3PO4). The coated silicon wafers were put inside the conventional furnace for predepostion and drive in oxidation. Effect caused by varying the molarity of the acid were observed and studied using Hall Effect measurement by comparing their differences in sheet resistance, mobility, resistivity as well as sheet and bulk concentaration.

  4. Immobilization of Biocatalysts and Cells on Hybrid Membranes Syntheses on Sol-gel Method

    Directory of Open Access Journals (Sweden)

    Yotova L.

    2007-12-01

    Full Text Available The investigations in the area of enzyme action in the living organisms give us the opportunity for applications of these biochemical catalysts in the different purposes of medicine, industry and analytical practice. Using of soluble enzymes is connected with many difficulties, because the enzymes are no regenerative and they are instability. By immobilization of the enzymes on to different carriers the more of these problems are overcome. The application of soluble enzymes caused many difficulties, by the reason that the enzymes can not be regenerated. The immobilization of the enzymes by means of different reagents and carriers overcomes this problem. The aim of this study to develop a sol-gel method of synthesis of new hybrid membrane, with immobilized biocatalysts (microbial cells and enzymes for biosensor construction. This study shows that hybrid organic-inorganic membranes were synthesized.

  5. Modified sol-gel method used for obtaining SOFC electrolyte materials

    Energy Technology Data Exchange (ETDEWEB)

    Suciu, C.; Maeland, D.; Hoffmann, A.C. [Bergen Univ., Bergen (Norway). Dept. of Physics and Technology; Dorolti, E.; Tetean, R. [Babes-Bolyai Univ., Cluj-Napoca (Romania). Faculty of Physics

    2009-07-01

    Solid oxide fuel cells (SOFCs) offer significant advantages over conventional energy generation technologies. However, increases in current density and reliability must be achieved in order to ensure the commercialization of SOFCs. This study used a modified sol-gel method with sucrose and pectin as organic precursors to obtain a 6 and 10 mol per cent scandia stabilized zirconia (SSZ) electrolyte material. The SSZ electrolyte offered higher conductivity, while the organic precursors helped to reduce the high cost of the SSZ. The composite powders were pressed as pellets and sintered at 1400 degrees C for 16 hours at a temperature of 200 degrees C. Transmission electron microscopy (TEM), X-ray diffraction, BET and electronic impedance spectroscopy (EIP) were used to analyze the morphology, particle and crystallite size, crystal structure and specific surface area of the pellets. The electrical properties of the sintered pellets were also analyzed.

  6. Formation of superhydrophobic boehmite film on glass substrate by Sol-Gel method

    Institute of Scientific and Technical Information of China (English)

    Xinhui FANG; Zhijia YU; Xiangyu SUN; Xinbua LIU; Futao QIN

    2009-01-01

    Superhydrophobic boehmite film has been successfully prepared on a glass substrate by a sol-gel method. A chelated Aluminum-sec-butoxide (Al(OBus)3)solution, instead of aluminum hydroxide collosol, was used for the film coating. By immersing the film in boiling water, boehmite crystal was formed on a glass substrate.Subsequently, the rough surface was modified with fluoroalkylsilane (FAS). The result shows that the water droplet contact angle on the surface is 168.3°. The super-water-repellency is caused by the micro-nano structure and the low surface energy of the fluorinated surface. The reaction mechanism is proposed with the help of SEM,XRD and FT-IR analysis.

  7. The morphological characterizations of titanium dioxide (TiO2) via sol-gel method

    Science.gov (United States)

    Nordin, N. K. S.; Hashim, U.; Vijayakumaran, T.

    2017-03-01

    Titanium Dioxide (TiO2) has comes with many fascinating properties in environmental purification, photocatalytic activity and in sensor application. TiO2 is prepared by sol-gel method and been coated on the silicon oxide (SiO) and glasses for 1 layer, 3 layers, 5 layers and finally 7 layers to find the best layer for coating purpose. A few characterizations had been carried out such as Scanning Electron Microscope (SEM), Photoluminescence (PL) and Current-Voltage (I-V) measurement for TiO2. The I-V recorded for the presence of Interdigitated Electrode (IDE) is 2.46×10-10 at 1V increased from 2.24×10-10 without the coating of TiO2. TiO2 coated on IDE triggered more sensitive sensor compared to IDE without metal oxides coated.

  8. Superparamagnetic calcium ferrite nanoparticles synthesized using a simple sol-gel method for targeted drug delivery.

    Science.gov (United States)

    Sulaiman, N H; Ghazali, M J; Majlis, B Y; Yunas, J; Razali, M

    2015-01-01

    The calcium ferrite nano-particles (CaFe2O4 NPs) were synthesized using a sol-gel method for targeted drug delivery application. The proposed nano-particles were initially prepared by mixing calcium and iron nitrates that were added with citric acid in order to prevent agglomeration and subsequently calcined at a temperature of 550°C to obtain small particle size. The prepared nanoparticles were characterized by using an XRD (X-ray diffraction), which revealed the configuration of orthorhombic structures of the CaFe2O4 nano-particles. A crystallite size of ~13.59 nm was obtained using a Scherer's formula. Magnetic analysis using a VSM (Vibrating Sample Magnetometer analysis), revealed that the synthesized particles exhibited super-paramagnetic behavior having magnetization saturation of approximately 88.3emu/g. Detailed observation via the scanning electron microscopy (SEM) showed the calcium ferrite nano-particles were spherical in shape.

  9. Massive clot formation after tooth extraction

    Directory of Open Access Journals (Sweden)

    Santosh Hunasgi

    2015-01-01

    Full Text Available Oral surgical procedures mainly tooth extraction can be related with an extended hemorrhage owed to the nature of the process resulting in an "open wound." The attempt of this paper is to present a case of massive postoperative clot formation after tooth extraction and highlight on the oral complications of surgical procedures. A 32-year-old male patient reported to the Dental Clinic for evaluation and extraction of grossly decayed 46. Clinical evaluation of 46 revealed root stumps. Extraction of the root stumps was performed, and it was uneventful. Hemostasis was achieved and postsurgical instructions were specified to the patient. The patient reported to the clinic, the very subsequent morning with a criticism of bleeding at the extraction site. On clinical examination, bleeding was noted from the socket in relation to 46. To control bleeding, oral hemostatic drugs Revici - E (Ethamsylate 500 mg was prescribed and bleeding was stopped in 2 h. However, a massive clot was formed at the extraction site. Further, this clot resolved on its own in 1-week time. Despite the fact that dental extraction is considered to be a minor surgical procedure, some cases may present with life-threatening complications including hemorrhage. Vigilant and significant history taking, physical and dental examinations prior to dental procedures are a must to avoid intraoperative and postoperative complications.

  10. Mullite long fibres prepared by sol-gel method using water solvent systems

    Energy Technology Data Exchange (ETDEWEB)

    Okada, K.; Yasohama, S.; Hayashi, S.; Yasumori, A. [Tokyo Inst. of Tech. (Japan). Dept. of Inorganic Materials

    1997-12-31

    Mullite long fibres, which are a candidate for high temperature applications were prepared by sol-gel method from water solvent systems. They were synthesized from three different combinations of raw materials as follows: (1):Al(O{sub 1}C{sub 3}H{sub 7}){sub 3}, Al-nitrate and Si(OC{sub 2}H{sub 5}){sub 4} (TEOS), (2):Al metal, Al-chloride and TEOS, (3):Al metal, Al-nitrate and TEOS. In the methods (1) and (2), very fine SiO{sub 2} aerosol particles were also used partially replacing TEOS. The prepared solutions were condensed and examined the spinability by a hand drawing method. Dense and crack free mullite fibres were prepared from the methods (1) and (3) by firing up to 1100 C. Whereas the fibres prepared from the method (2) were less SiO{sub 2} than mullite composition and were porous by the firing due to evaporation of residual Cl ions at high temperature. (orig.) 10 refs.

  11. Preparation of mullite fiber sol-gel method. Sol-gel ho ni yoru mullite sen prime i no gosei

    Energy Technology Data Exchange (ETDEWEB)

    Nishio, T. (Unichika Ltd., Osaka (Japan)); Fujiki, Y. (National Institute for Research and Inorganic Materials, Tsukuba (Japan))

    1991-08-01

    This report discribes a method to prepare mullite fiber by a new process using aqueous solution of aluminum nitrate, aluminum isopropoxide, and tetraethoxisilane(TEOS). Presursors of mullite were obtained by a method to add aluminum isopropoxide and TEOS simultaneously to the solution of aluminum nitrate, or by another method to add TEOS after adding aluminum isopropoxide. Then, structural analyses on the spinning solution, precursor fibers, and calcination process were carried out by {sup 27}Al- and {sup 29}Si-NMR, X-ray diffraction analysis, and DTA. The spinnable range of the method to add aluminum isopropoxide and TEOS at the same time was wider when it was shown with H{sub 2}O mol/(Al+Si)mol and Al(OPr{sup i}){sub 3} mol/Al(NO{sub 3}){sub 3} mol. Manifastation of spinnability deeply related to the bonding condition of Al and Si formed in the solution. 27 refs., 7 figs., 1 tab.

  12. Influence of styptic fiber on clotting time in rabbits

    Institute of Scientific and Technical Information of China (English)

    LU Jun; JIANG Su-yun

    2008-01-01

    Objective To explore the influence of styptic fiber on clotting time in rabbits so as to provide experiment data for its development. Methods Onto 0.1 mL aliquots of citrated anti-coagulant rabbit blood placed in a surfacial plate 25 ul of 0.2 mol·L-1 CaCl2 solution was dropped, and mixed well with glass stirrer;the resulting mixture was immediately capped with a piece of styptic fiber (test product group) or absorptive gelatin sponge(positive control group) of 2 cm diameter. Then, the surficial plate was rinsed with 30ml of purified water at 5, 10, 20, 30, 40 and 50 min after capping; the rinsings were allowed to stand for 1 h and were subjected to OD determination at a wavelength of 541 nm. The above procedure was repeated twice, the average value of the twice experiments was taken for evaluation of the hemostatic effect of test product. For negative control group, all procedures except for capping were same as the test product group. The haemostatic effect was judged by percent OD relative to OD at 0 min in negative control group (OD 0 min) (OD 0 min was considered as 100% );if OD value at a time was less than 80% of OD 0 min, it should be designated as primary clotting time(PCT), less than 20 96 as complete clotting time(CCT). Results The measured PCT was 20min for both negative and positive control groups;CCT was 50, 30 and 5 min for negative control, positive control and test product groups, respectively, showing the test styptic fiber had a CCT 8 times shorter than untreated blood, 10 times shorter than negative control and 6 times shorter than positive control. Conclusions The test styptic fiber has powerful hemostatic effect.

  13. A turbidimetric assay for the measurement of clotting times of procoagulant venoms in plasma.

    Science.gov (United States)

    O'Leary, Margaret A; Isbister, Geoffrey K

    2010-01-01

    Assessment of the procoagulant effect of snake venoms is important for understanding their effects. The aim of this study was to develop a simple automated method to measure clotting times to assess procoagulant venoms. A turbidimetric assay was developed which monitors changes in optical density when plasma and venom are mixed. Plasma was added simultaneously to venom solutions in a 96 well microtitre plate. After mixing, the optical density at 340 nm was monitored in a microplate reader every 30 s over 30 min. The clotting time was defined as the lag time until the absorbance sharply increased. The turbidimetric method was compared to manual measurement of the clotting time defined as the time when a strand of fibrin can be drawn out of the mixture. The two methods were done simultaneously, with the same venom and plasma, and compared by plotting the manual versus turbidimetric clotting times. Within-day and between-day runs were done and the coefficient of variation (CV) was calculated. Plots comparing manual clotting times to the lag time in the turbidimetric assay showed good correlation between the two methods for brown snake (Pseudonaja textilis) venom, including 24 determinations in triplicate over six days for seven different venom concentrations. Good correlation was also found for four other venoms: tiger snake (Notechis scutatus), Carpet viper (Echis carinatus), Russell's viper (Daboia russelii) and Malaysian pit piper (Calloselasma rhodostoma). Between-day CV was in the range 10-20% for both methods, while within-day CV <10%. The turbidimetric assay appears to be a simple and convenient automated method for the measurement of clotting times to assess the effects of procoagulant venoms. Crown Copyright 2009. Published by Elsevier Inc. All rights reserved.

  14. Characterization of Nanostructured n-ZnO/p-Si Heterojunction Prepared by a Simple Sol-Gel Method

    Science.gov (United States)

    He, Bo; Xu, Jing; Ning, Huanpo; Xiong, Hao; Xing, Huaizhong; Qin, Yuming

    2016-03-01

    The nanostructured ZnO film was prepared on a texturized Si wafer by a simple sol-gel method to fabricate n-ZnO/p-Si heterojunction photoelectric device. The novel sol-gel method is cheap and convenient. The structural, optical and electrical properties of the nanostructured ZnO film were studied by XRD, SEM, XPS, PL, UV-Vis spectrophotometer and Hall effect measurement. The current-voltage (I-V) curve of nanostructured ZnO/p-Si heterojunction device shows good rectifying behavior. Good photoelectric behavior is obtained.

  15. Method for separating constituents from solution employing a recyclable Lewis acid metal-hydroxy gel

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, D.H.

    1995-12-31

    This invention permits radionuclides, heavy metals, and organics to be extracted from solution by scavenging them with an amorphous gel. In the preferred embodiment, a contaminated solution (e.g. from soil washing, decontamination, or groundwater pumping) is transferred to a reaction vessel. The contaminated solution is contacted by the sequestering reagent which might contain for example, aluminate and EDTA anions in a 2.5 M NaOH solution. The pH of the reagent bearing solution is lowered on contact with the contaminated solution, or for example by bubbling carbon dioxide through it, causing an aluminum hydroxide gel to precipitate as the solution drops below the range of 1.8 to 2.5 molar NaOH (less than pH 14). This precipitating gel scavenges waste contaminants as it settles through solution leaving a clean supernatant which is then separated from the gel residue by physical means such as centrifugation, or simple settling. The gel residue containing concentrated contaminants is then redissolved releasing contaminants for separations and processing. This is a critical point: the stabilized gel used in this invention is readily re-dissolved by merely increasing the pH above the gels phase transition to aqueous anions. Thus, concentrated contaminants trapped in the gel can be released for convenient separation from the sequestering reagent, and said reagent can then be recycled.

  16. Platelet factor XIII increases the fibrinolytic resistance of platelet-rich clots by accelerating the crosslinking of alpha 2-antiplasmin to fibrin

    Science.gov (United States)

    Reed, G. L.; Matsueda, G. R.; Haber, E.

    1992-01-01

    Platelet clots resist fibrinolysis by plasminogen activators. We hypothesized that platelet factor XIII may enhance the fibrinolytic resistance of platelet-rich clots by catalyzing the crosslinking of alpha 2-antiplasmin (alpha 2AP) to fibrin. Analysis of plasma clot structure by polyacrylamide gel electrophoresis and immunoblotting revealed accelerated alpha 2AP-fibrin crosslinking in platelet-rich compared with platelet-depleted plasma clots. A similar study of clots formed with purified fibrinogen (depleted of factor XIII activity), isolated platelets, and specific factor XIII inhibitors indicated that this accelerated crosslinking was due to the catalytic activity of platelet factor XIII. Moreover, when washed platelets were aggregated by thrombin, there was evidence of platelet factor XIII-mediated crosslinking between platelet alpha 2AP and platelet fibrin(ogen). Specific inhibition (by a monoclonal antibody) of the alpha 2AP associated with washed platelet aggregates accelerated the fibrinolysis of the platelet aggregate. Thus in platelet-rich plasma clots, and in thrombin-induced platelet aggregates, platelet factor XIII actively formed alpha 2AP-fibrin crosslinks, which appeared to enhance the resistance of platelet-rich clots to fibrinolysis.

  17. Fractal dimension (df) as a new structural biomarker of clot microstructure in different stages of lung cancer.

    Science.gov (United States)

    Davies, Nia Anne; Harrison, Nicholas Kim; Morris, Roger H Keith; Noble, Simon; Lawrence, Matthew James; D'Silva, Lindsay Antonio; Broome, Laura; Brown, Martin Rowan; Hawkins, Karl M; Williams, Phylip Rhodri; Davidson, Simon; Evans, Phillip Adrian

    2015-11-25

    Venous thromboembolism (VTE) is common in cancer patients, and is the second commonest cause of death associated with the disease. Patients with chronic inflammation, such as cancer, have been shown to have pathological clot structures with modulated mechanical properties. Fractal dimension (df) is a new technique which has been shown to act as a marker of the microstructure and mechanical properties of blood clots, and can be performed more readily than current methods such as scanning electron microscopy (SEM). We measured df in 87 consecutive patients with newly diagnosed lung cancer prior to treatment and 47 matched-controls. Mean group values were compared for all patients with lung cancer vs controls and for limited disease vs extensive disease. Results were compared with conventional markers of coagulation, fibrinolysis and SEM images. Significantly higher values of df were observed in lung cancer patients compared with controls and patients with extensive disease had higher values than those with limited disease (p< 0.05), whilst conventional markers failed to distinguish between these groups. The relationship between df of the incipient clot and mature clot microstructure was confirmed by SEM and computational modelling: higher df was associated with highly dense clots formed of smaller fibrin fibres in lung cancer patients compared to controls. This study demonstrates that df is a sensitive technique which quantifies the structure and mechanical properties of blood clots in patients with lung cancer. Our data suggests that df has the potential to identify patients with an abnormal clot microstructure and greatest VTE risk.

  18. Preparation and optical properties of iron-modified titanium dioxide obtained by sol-gel method

    Science.gov (United States)

    Hreniak, Agnieszka; Gryzło, Katarzyna; Boharewicz, Bartosz; Sikora, Andrzej; Chmielowiec, Jacek; Iwan, Agnieszka

    2015-08-01

    In this paper twelve TiO2:Fe powders prepared by sol-gel method were analyzed being into consideration the kind of iron compound applied. As a precursor titanium (IV) isopropoxide (TIPO) was used, while as source of iron Fe(NO3)3 or FeCl3 were tested. Fe doped TiO2 was obtained using two methods of synthesis, where different amount of iron was added (1, 5 or 10% w/w). The size of obtained TiO2:Fe particles depends on the iron compound applied and was found in the range 80-300 nm as it was confirmed by SEM technique. TiO2:Fe particles were additionally investigated by dynamic light scattering (DLS) method. Additionally, for the TiO2:Fe particles UV-vis absorption and the zeta potential were analyzed. Selected powders were additionally investigated by magnetic force microscopy (MFM) and X-ray diffraction techniques. Photocatalytic ability of Fe doped TiO2 powders was evaluated by means of cholesteryl hemisuccinate (CHOL) degradation experiment conducted under the 30 min irradiation of simulated solar light.

  19. New synthesis parameters of GGG:Nd nanocrystalline powder prepared by sol–gel method: Structural and spectroscopic investigation

    Energy Technology Data Exchange (ETDEWEB)

    Alshikh Mohamad, Yassin, E-mail: yassinm@mail.ru; Atassi, Yomen; Moussa, Zafer

    2015-09-15

    GGG:Nd nanopowder is synthesized by the sol–gel method using formic acid and acetic acid as chelating agents and ethylene glycol as a cross linking agent. TGA–DSC, XRD, photoluminescence spectroscopy and fluorescence life time analysis (τ) are used to characterize the powder. XRD is used to optimize the synthesis parameters. According to XRD, complete phase of GGG nanopowder is formed at 800 °C for 1 min. Fluorescence life time analyses reveal that the optimum crystallization temperature is 1000 °C. - Highlights: • GGG:Nd nanopowder was prepared using formic acid by the sol gel method. • Optimization of sol gel parameters was done. • GGG phase formation was complete at 800 °C for 1 min • According to τ measurements, optimal temperature treatment is at 1000 °C. • Nanopowder prepared with formic acid was better than that formed with acetic acid.

  20. Agarose and Polyacrylamide Gel Electrophoresis Methods for Molecular Mass Analysis of 5–500 kDa Hyaluronan

    Science.gov (United States)

    Bhilocha, Shardul; Amin, Ripal; Pandya, Monika; Yuan, Han; Tank, Mihir; LoBello, Jaclyn; Shytuhina, Anastasia; Wang, Wenlan; Wisniewski, Hans-Georg; de la Motte, Carol; Cowman, Mary K.

    2011-01-01

    Agarose and polyacrylamide gel electrophoresis systems for the molecular mass-dependent separation of hyaluronan (HA) in the size range of approximately 5–500 kDa have been investigated. For agarose-based systems, the suitability of different agarose types, agarose concentrations, and buffers systems were determined. Using chemoenzymatically synthesized HA standards of low polydispersity, the molecular mass range was determined for each gel composition, over which the relationship between HA mobility and logarithm of the molecular mass was linear. Excellent linear calibration was obtained for HA molecular mass as low as approximately 9 kDa in agarose gels. For higher resolution separation, and for extension to molecular masses as low as approximately 5 kDa, gradient polyacrylamide gels were superior. Densitometric scanning of stained gels allowed analysis of the range of molecular masses present in a sample, and calculation of weight-average and number-average values. The methods were validated for polydisperse HA samples with viscosity-average molecular masses of 112, 59, 37, and 22 kDa, at sample loads of 0.5 µg (for polyacrylamide) to 2.5 µg (for agarose). Use of the methods for electrophoretic mobility shift assays was demonstrated for binding of the HA-binding region of aggrecan (recombinant human aggrecan G1-IGD-G2 domains) to a 150 kDa HA standard. PMID:21684248

  1. In vivo ultrasound visualization of non-occlusive blood clots with thrombin-sensitive contrast agents.

    Science.gov (United States)

    Nakatsuka, Matthew A; Barback, Christopher V; Fitch, Kirsten R; Farwell, Alexander R; Esener, Sadik C; Mattrey, Robert F; Cha, Jennifer N; Goodwin, Andrew P

    2013-12-01

    The use of microbubbles as ultrasound contrast agents is one of the primary methods to diagnose deep venous thrombosis. However, current microbubble imaging strategies require either a clot sufficiently large to produce a circulation filling defect or a clot with sufficient vascularization to allow for targeted accumulation of contrast agents. Previously, we reported the design of a microbubble formulation that modulated its ability to generate ultrasound contrast from interaction with thrombin through incorporation of aptamer-containing DNA crosslinks in the encapsulating shell, enabling the measurement of a local chemical environment by changes in acoustic activity. However, this contrast agent lacked sufficient stability and lifetime in blood to be used as a diagnostic tool. Here we describe a PEG-stabilized, thrombin-activated microbubble (PSTA-MB) with sufficient stability to be used in vivo in circulation with no change in biomarker sensitivity. In the presence of actively clotting blood, PSTA-MBs showed a 5-fold increase in acoustic activity. Specificity for the presence of thrombin and stability under constant shear flow were demonstrated in a home-built in vitro model. Finally, PSTA-MBs were able to detect the presence of an active clot within the vena cava of a rabbit sufficiently small as to not be visible by current non-specific contrast agents. By activating in non-occlusive environments, these contrast agents will be able to detect clots not diagnosable by current contrast agents. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Investigation of the gold nanoparticles effects on the prostate dose distribution in brachytherapy: gel dosimetry and Monte Carlo method

    Science.gov (United States)

    Hashemi, Bijan; Rahmani, Faezeh; Ebadi, Ahmad

    2016-01-01

    Purpose In this work, gold nanoparticles (GNPs) were embedded in the MAGIC-f polymer gel irradiated with the 192Ir brachytherapy sources. Material and methods At the first plexiglas phantom was made as the human pelvis. The GNPs were synthesized with 15 nm in diameter and 0.1 mM (0.0197 mg/ml) in concentration by using a chemical reduction method. Then, the MAGIC-f gel was synthesized. The fabricated gel was poured into the tubes located at the prostate (with and without the GNPs) locations of the phantom. The phantom was irradiated with 192Ir brachytherapy sources for prostate cancer. After 24 hours, the irradiated gels was read by using Siemens 1.5 Tesla MRI scanner. Following the brachytherapy practices, the absolute doses at the reference points and isodose curves were extracted and compared by experimental measurements and Monte Carlo (MC) simulations. Results The mean absorbed doses in the presence of the GNPs in prostate were 14% higher than the corresponding values without the GNPs in the brachytherapy. The gamma index analysis (between gel and MC) using 7%/7 mm was also applied to the data and a high pass rate achieved (91.7% and 86.4% for analysis with/without GNPs, respectively). Conclusions The real three-dimensional analysis shows the comparison of the dose-volume histograms measured for planning volumes and the expected one from the MC calculation. The results indicate that the polymer gel dosimetry method, which developed and used in this study, could be recommended as a reliable method for investigating the dose enhancement factor of GNPs in brachytherapy. PMID:27895684

  3. Hydroxyapatite, fluor-hydroxyapatite and fluorapatite produced via the sol-gel method: bonding to titanium and scanning electron microscopy.

    Science.gov (United States)

    Tredwin, Christopher J; Georgiou, George; Kim, Hae-Won; Knowles, Jonathan C

    2013-05-01

    Hydroxyapatite (HA), fluor-hydroxyapatite (FHA) with varying levels of fluoride ion substitution and fluorapatite (FA) production has been characterised and optimised by the sol-gel method and the dissolution and biological properties of these materials were investigated. It was the objective of this study to investigate the potential bond strength and interaction of these materials with titanium. HA, FHA and FA were synthesised by a sol-gel method. Calcium nitrate and triethyl phosphite were used as precursors under an ethanol-water based solution. Different amounts of ammonium fluoride (NH4F) were incorporated for the preparation of the FHA and FA sol-gels. Using a spin coating technique the sol-gels were coated onto commercially pure titanium disks and crystallised at various temperatures. Using scanning electron microscopy (SEM) and elemental analysis, the surface characteristics, coating thickness and interaction of the Ti substrate and coating were investigated. The bond strengths of the coating to the Ti were investigated using an Instron Universal Load Testing Machine. Statistical analysis was performed with a two-way analysis of variance and post hoc testing with a Bonferroni correction. (1) Coating speed inversely influenced the coating thickness. (2) Increasing fluoride ion substitution and heating temperature significantly increased bond strength and (3) increasing fluoride ion substitution increased the coating thickness. FHA and FA synthesised using the sol-gel technique may offer a superior alternative to coating titanium implants with HA and plasma spraying. HA, FHA and FA materials synthesised by the sol-gel method may also have a use as bone grafting materials. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  4. Data Visualization and Feature Selection Methods in Gel-based Proteomics

    DEFF Research Database (Denmark)

    Silva, Tomé Santos; Richard, Nadege; Dias, Jorge P.;

    2014-01-01

    Despite the increasing popularity of gel-free proteomic strategies, two-dimensional gel electrophoresis (2DE) is still the most widely used approach in top-down proteomic studies, for all sorts of biological models. In order to achieve meaningful biological insight using 2DE approaches, importance......-based proteomics, summarizing the current state of research within this field. Particular focus is given on discussing the usefulness of available multivariate analysis tools both for data visualization and feature selection purposes. Visual examples are given using a real gel-based proteomic dataset as basis....

  5. Development of durable self-cleaning coatings using organic–inorganic hybrid sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Divya [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Wu, Xinghua [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Energy Research Institute at NTU - ERI@N, 1 CleanTech Loop, #06-04, CleanTech One, Singapore 637141 (Singapore); Fu, Qitao [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Ho, Jeffrey Weng Chye [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Energy Research Institute at NTU - ERI@N, 1 CleanTech Loop, #06-04, CleanTech One, Singapore 637141 (Singapore); Kanhere, Pushkar D. [Energy Research Institute at NTU - ERI@N, 1 CleanTech Loop, #06-04, CleanTech One, Singapore 637141 (Singapore); Li, Lin [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Chen, Zhong, E-mail: ASZChen@ntu.edu.sg [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Energy Research Institute at NTU - ERI@N, 1 CleanTech Loop, #06-04, CleanTech One, Singapore 637141 (Singapore)

    2015-07-30

    Highlights: • A facile method to produce sol–gel based self-cleaning coatings is described. • Effect of filler size and content is evaluated via contact angle, sliding angle, and surface morphology. • Coating with 15 wt.% nano-sized silica fillers exhibits the best self-cleaning performance. • The coatings are resistant to UV radiation and retain the functionality after the abrasion test. • A self-cleaning test and scheme to quantify the self-cleaning efficiency are described in this work. - Abstract: Self-cleaning coatings with excellent water-repellence and good mechanical properties are in high demand. However, producing such coatings with resistance to mechanical abrasion and environmental weathering remains a key challenge. Mechanically robust coatings based on tetraethylorthosilicate (TEOS) and glycidoxypropyltriethoxysilane (Glymo) have been prepared using a sol–gel method. Emphasis is given to the addition of Glymo, an epoxy silane which creates an organic matrix that blends with the inorganic Si−O−Si matrix formed from the TEOS. The combination of the blended matrix produced coatings with good adhesion to substrates and improved mechanical properties. Fluoroalkylsilane (FAS) and silica fillers were introduced to increase the hydrophobicity of the coating. It was found that the water contact angle (CA) of these coatings increases from 115° to 164° upon decreasing filler size from 1–5 μm to 10–20 nm. The sliding angle (SA) for coatings with 15 wt.% loading of 10–20 nm silica is around 2°. UV weathering does not show significant effect on the properties of the coatings. Mechanical properties and performances including hardness, Young's modulus, coating adhesion and abrasion resistance were systematically analyzed. In the current work, a simple self-cleaning test, which measures the extent of dirt accumulation and subsequent removal by water spray, was performed. The coatings with 15 wt.% loading of 10–20 nm silica particles

  6. Ce-doped YAG phosphors prepared via sol–gel method: Effect of some modular parameters

    Energy Technology Data Exchange (ETDEWEB)

    Boukerika, A., E-mail: assia1618@gmail.com [Laser Department/Nuclear Research Centre of Algiers (CRNA), 02, Boulevard Frantz Fanon, B.P. 399, Algiers 16000 (Algeria); Laboratory of Materials Study, Faculty of Science, Department of Physics, Jijel University, B.P. 98, Ouled Aissa, Jijel 18000 (Algeria); Guerbous, L., E-mail: guerbous@yahoo.fr [Laboratory of Materials Study, Faculty of Science, Department of Physics, Jijel University, B.P. 98, Ouled Aissa, Jijel 18000 (Algeria); Brihi, N. [Laboratory of Materials Study, Faculty of Science, Department of Physics, Jijel University, B.P. 98, Ouled Aissa, Jijel 18000 (Algeria)

    2014-11-25

    Highlights: • Ce-doped YAG phosphor powders have been prepared using sol-gel method. • The influence of complexing agent and the molar ratio on some properties have been studied. • The effect of ethylene glycol and citric acid on the structural and luminescence havebeen discussed. • The specific role of molar ratio between ethylene glycol and citric acid has been studied. • The effect of pH on the pure phase and luminescence property of YAG: Ce has been discussed. - Abstract: Cerium doped yttrium aluminum garnet (YAG:Ce{sup 3+}) nanopowders have been synthesized using sol–gel method. Different synthesized parameters such as molar ratio of citric acid and ethylene glycol to the total metallic ions, complexing molar ratio and pH of the solution have been changed and their influence on structural and luminescence properties have been investigated. Thermal gravimetry and differential scanning calorimetry (TG/DSC), X-ray diffraction technique (XRD), Fourier transforms infrared spectroscopy (FTIR) and photoluminescence (PL) have been used to characterize the samples. Single cubic phase YAG was formed with pH ⩽ 4 and for pH ⩾ 6 additional impurities crystalline phase namely Y{sub 4}Al{sub 2}O{sub 9} (YAM) and YAlO{sub 3} (YAP) have been detected. All samples exhibit intense broad green–yellow emission band in the range of 460–700 nm with a maximum intensity at around 530 nm assigned to the 5d → 4f ({sup 2}F{sub 5/2}, {sup 2}F{sub 7/2}) interconfigurationnelles transitions of Ce{sup 3+} ion in YAG nanomaterial. The origin of the highest emission intensity obtained for pH = 4, citric acid to the total metallic ions of 1:1 (CA:M{sup 3+}, of 1:1) and a molar ratio of ethylene glycol:citric acid corresponding to 2:1 (EG:CA = 2:1) parameters are discussed.

  7. Protein-membrane interactions: blood clotting on nanoscale bilayers.

    Science.gov (United States)

    Morrissey, J H; Pureza, V; Davis-Harrison, R L; Sligar, S G; Rienstra, C M; Kijac, A Z; Ohkubo, Y Z; Tajkhorshid, E

    2009-07-01

    The clotting cascade requires the assembly of protease-cofactor complexes on membranes with exposed anionic phospholipids. Despite their importance, protein-membrane interactions in clotting remain relatively poorly understood. Calcium ions are known to induce anionic phospholipids to cluster, and we propose that clotting proteins assemble preferentially on such anionic lipid-rich microdomains. Until recently, there was no way to control the partitioning of clotting proteins into or out of specific membrane microdomains, so experimenters only knew the average contributions of phospholipids to blood clotting. The development of nanoscale membrane bilayers (Nanodiscs) has now allowed us to probe, with nanometer resolution, how local variations in phospholipid composition regulate the activity of key protease-cofactor complexes in blood clotting. Furthermore, exciting new progress in solid-state NMR and large-scale molecular dynamics simulations allow structural insights into interactions between proteins and membrane surfaces with atomic resolution.

  8. Benchmarking sample preparation/digestion protocols reveals tube-gel being a fast and repeatable method for quantitative proteomics.

    Science.gov (United States)

    Muller, Leslie; Fornecker, Luc; Van Dorsselaer, Alain; Cianférani, Sarah; Carapito, Christine

    2016-12-01

    Sample preparation, typically by in-solution or in-gel approaches, has a strong influence on the accuracy and robustness of quantitative proteomics workflows. The major benefit of in-gel procedures is their compatibility with detergents (such as SDS) for protein solubilization. However, SDS-PAGE is a time-consuming approach. Tube-gel (TG) preparation circumvents this drawback as it involves directly trapping the sample in a polyacrylamide gel matrix without electrophoresis. We report here the first global label-free quantitative comparison between TG, stacking gel (SG), and basic liquid digestion (LD). A series of UPS1 standard mixtures (at 0.5, 1, 2.5, 5, 10, and 25 fmol) were spiked in a complex yeast lysate background. TG preparation allowed more yeast proteins to be identified than did the SG and LD approaches, with mean numbers of 1979, 1788, and 1323 proteins identified, respectively. Furthermore, the TG method proved equivalent to SG and superior to LD in terms of the repeatability of the subsequent experiments, with mean CV for yeast protein label-free quantifications of 7, 9, and 10%. Finally, known variant UPS1 proteins were successfully detected in the TG-prepared sample within a complex background with high sensitivity. All the data from this study are accessible on ProteomeXchange (PXD003841).

  9. Hydroxyapatite, fluor-hydroxyapatite and fluorapatite produced via the sol-gel method: dissolution behaviour and biological properties after crystallisation.

    Science.gov (United States)

    Tredwin, Christopher J; Young, Anne M; Abou Neel, Ensanya A; Georgiou, George; Knowles, Jonathan C

    2014-01-01

    Hydroxyapatite (HA), fluor-hydroxyapatite (FHA) with varying levels of fluoride ion substitution and fluorapatite (FA) were synthesised by the sol-gel method as possible implant coating or bone-grafting materials. Calcium nitrate and triethyl phosphite were used as precursors under an ethanol-water based solution. Different amounts of ammonium fluoride were incorporated for the preparation of the FHA and FA sol-gels. After heating and powdering the sol-gels, dissolution behaviour was assessed using ion chromatography to measure Ca(2+) and PO4 (3-) ion release. Biological behaviour was assessed using cellular proliferation with human osteosarcoma cells and alamarBlue™ assay. Statistical analysis was performed with a two way analysis of variance and post hoc testing with a Bonferroni correction. Increasing fluoride substitution into an apatite structure decreased the dissolution rate. Increasing the firing temperature of the HA, FHA and FA sol-gels up to 1,000 °C decreased the dissolution rate. There was significantly higher cellular proliferation on highly substituted FHA and FA than on HA or Titanium. The properties of an implant coating or bone grafting material can be tailored to meet specific requirements by altering the amount of fluoride that is incorporated into the original apatite structure. The dissolution behaviour can further be altered by the temperature at which the sol-gel is fired.

  10. A novel method of estimating dose responses for polymer gels using texture analysis of scanning electron microscopy images.

    Directory of Open Access Journals (Sweden)

    Cheng-Ting Shih

    Full Text Available Polymer gels are regarded as a potential dosimeter for independent validation of absorbed doses in clinical radiotherapy. Several imaging modalities have been used to convert radiation-induced polymerization to absorbed doses from a macro-scale viewpoint. This study developed a novel dose conversion mechanism by texture analysis of scanning electron microscopy (SEM images. The modified N-isopropyl-acrylamide (NIPAM gels were prepared under normoxic conditions, and were administered radiation doses from 5 to 20 Gy. After freeze drying, the gel samples were sliced for SEM scanning with 50×, 500×, and 3500× magnifications. Four texture indices were calculated based on the gray level co-occurrence matrix (GLCM. The results showed that entropy and homogeneity were more suitable than contrast and energy as dose indices for higher linearity and sensitivity of the dose response curves. After parameter optimization, an R (2 value of 0.993 can be achieved for homogeneity using 500× magnified SEM images with 27 pixel offsets and no outlier exclusion. For dose verification, the percentage errors between the prescribed dose and the measured dose for 5, 10, 15, and 20 Gy were -7.60%, 5.80%, 2.53%, and -0.95%, respectively. We conclude that texture analysis can be applied to the SEM images of gel dosimeters to accurately convert micro-scale structural features to absorbed doses. The proposed method may extend the feasibility of applying gel dosimeters in the fields of diagnostic radiology and radiation protection.

  11. A novel method of estimating dose responses for polymer gels using texture analysis of scanning electron microscopy images.

    Science.gov (United States)

    Shih, Cheng-Ting; Hsu, Jui-Ting; Han, Rou-Ping; Hsieh, Bor-Tsung; Chang, Shu-Jun; Wu, Jay

    2013-01-01

    Polymer gels are regarded as a potential dosimeter for independent validation of absorbed doses in clinical radiotherapy. Several imaging modalities have been used to convert radiation-induced polymerization to absorbed doses from a macro-scale viewpoint. This study developed a novel dose conversion mechanism by texture analysis of scanning electron microscopy (SEM) images. The modified N-isopropyl-acrylamide (NIPAM) gels were prepared under normoxic conditions, and were administered radiation doses from 5 to 20 Gy. After freeze drying, the gel samples were sliced for SEM scanning with 50×, 500×, and 3500× magnifications. Four texture indices were calculated based on the gray level co-occurrence matrix (GLCM). The results showed that entropy and homogeneity were more suitable than contrast and energy as dose indices for higher linearity and sensitivity of the dose response curves. After parameter optimization, an R (2) value of 0.993 can be achieved for homogeneity using 500× magnified SEM images with 27 pixel offsets and no outlier exclusion. For dose verification, the percentage errors between the prescribed dose and the measured dose for 5, 10, 15, and 20 Gy were -7.60%, 5.80%, 2.53%, and -0.95%, respectively. We conclude that texture analysis can be applied to the SEM images of gel dosimeters to accurately convert micro-scale structural features to absorbed doses. The proposed method may extend the feasibility of applying gel dosimeters in the fields of diagnostic radiology and radiation protection.

  12. Crystal structure and luminescent properties of nanocrystalline YAG and YAG:Nd synthesized by sol-gel method

    Science.gov (United States)

    Zhydachevskii, Ya.; Syvorotka, I. I.; Vasylechko, L.; Sugak, D.; Borshchyshyn, I. D.; Luchechko, A. P.; Vakhula, Ya. I.; Ubizskii, S. B.; Vakiv, M. M.; Suchocki, A.

    2012-10-01

    The work describes results of synthesis of undoped and Nd-doped YAG nanopowders by sol-gel method using different complexing agents (ethylene glycol and citric acid) and characterization of the material by X-ray powder diffraction, scanning electron microscopy, photoluminescence and thermoluminescence techniques. Utilization of citrate sol-gel procedure using yttrium and aluminum nitrate nonahydrates as starting substances allowed to obtain highly stoichiometric and non-defected YAG and YAG:Nd nanocrystalline samples with good luminescence performance and low radiation storage efficiency.

  13. Growth of two-dimensional KGd(WO 4) 2 nanorods by modified sol-gel Pechini method

    Science.gov (United States)

    Thangaraju, D.; Samuel, P.; Moorthy Babu, S.

    2010-08-01

    KGd (WO 4) 2 nanocrystalline powder was obtained by modified sol-gel Pechini method. The synthesis procedure was optimized with TGA and DTA analyses. Synthesized polymeric resin was calcinated at 550 and 700 °C using resistive furnace in an open atmosphere. Crystallinity of annealed powder was confirmed using X-ray diffraction. Absorption peaks of FT-IR for gel and the annealed samples, at two different temperatures show the decomposition of citrate-ethylene glycol complex and formation of KGW particles. Raman analysis confirms that the derived particles have well constructed bridges of W-O-O-W. External morphology of the particles was analysed through SEM.

  14. A New Method to Study the Sol-gel Transition Process of Organic/Inorganic Hybrid Materials

    Institute of Scientific and Technical Information of China (English)

    GUO Bin; GAO Jian-gang; CHEN Da-zhu; LIU Jian-ping; HE Ping-sheng; ZHANG Qi-jin

    2005-01-01

    The sol-gel transition process of PMMA/SiO2 hybrid materials was first studied by means of the dynamic torsional vibration method. The different stages of the transition can be described by the change of torque. The temperature-dependent measurement of the gel time(tg) gives the possibility to determine the apparent activation energy(Ea) of this transition according to Flory′s gelation theory. The non-equilibrium thermodynamic fluctuation theory was used to predict the transition behavior. The isothermal transition experiments on hybrid sols with different TEOS(tetraethyl orthosilicate) contents were carried out. The results show that the Ea of a hybrid sol is higher than that of a non- hybrid sol of a TEOS-water-ethanol system. The increasing of TEOS content in a hybrid sol has no obvious effect on the Ea value, but it can enhance the sol-gel reaction rate.

  15. A method to determine Young's modulus of soft gels for cell adhesion

    Institute of Scientific and Technical Information of China (English)

    Xiaoling Peng; Jianyong Huang; Lei Qin; Chunyang Xiong; Jing Fang

    2009-01-01

    A convenient technique is reported in this note for measuring elastic modulus of extremely soft material for cellular adhesion. Specimens of bending cylinder under gravity are used to avoid contact problem between testing device and sample, and a beam model is presented for evaluating the curvatures of gel beams with large elastic deformation. A self-adaptive algorithm is also proposed to search for the best estimation of gels' elastic moduli by comparing the experimental bending curvatures with those computed from the beam model with preestimated moduli. Application to the measurement of the property of polyacrylamide gels indicates that the material compliance varies with the concentrations of bis-acrylamide, and the gels become softer after being immersed in a culture medium for a period of time, no matter to what extent they are polymerized.

  16. Growth and Characterizations of Pure and Calcium Doped Cadmium Tartrate Crystals by Silica Gel Method

    Directory of Open Access Journals (Sweden)

    N. S. Patil

    2014-10-01

    Full Text Available In the present course of investigation, pure and calcium doped cadmium tartrate crystals were grown in silica gel at room temperature. The optimum conditions were obtained by varying various parameters such as pH of gel, concentration of gel, gel setting time, concentration of reactants etc. Crystals having different morphologies were obtained such as whitish semitransparent, star shaped, needle shaped. Especially, effect of doping of calcium into cadmium tartrate has been studied with respect of size and transparency. It is found that doping enhances the size and transparency of the crystals. As-grown crystals were characterized using scanning electronic microscope (SEM, UV, Energy dispersive X-ray spectroscopy (EDAX.

  17. Bismuth Substituted Yttrium Iron Garnet Single Crystal Films Prepared by Sol-gel Method

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Magneto-optic Faraday rotation effect and the amount of bismuth substituted in yttrium iron garnet single crystal films prepared by gel-coating on modified gadolinium-gallium garnet substrates are investigated, where the gel is synthesized by a sol-gel reaction of nitrates and ethylene glycol. The coated gel is annealed in air at temperatures up to 660℃ for 4h, which is about 300℃ lower than that of liquid-phase epitaxy. The maximum amount of Bi substitution is x=2.7 and the crystallization temperature of garnet phase decreases with the increase of x down to 520℃ for x=2.7. In this film, a huge Faraday rotation of -8.1×104 (°)/cm at λ=0.633μm is obtained.

  18. Synthesis of nanocrystalline TiO2 by tartarate gel method

    Indian Academy of Sciences (India)

    S R Dhage; S P Gaikwad; V Ravi

    2004-12-01

    A gel was formed when a mixture of TiOCl2 and tartaric acid was heated on a water bath. Ultrafine powders of TiO2 in the anatase phase were formed, when the gel was decomposed at 623 K and the mole ratio of tartaric acid to titanium was 2. The anatase phase was converted into rutile phase on annealing at higher temperatures, > 773 K. When initial ratio of titanium to tartaric acid was < 2, the decomposition of gel leads to the formation of mixed phases of rutile and anatase. However, pure rutile phase was not formed by the decomposition of gel for any ratio of tartaric acid and titanium. These powders were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and surface area measurements. The average particle size obtained for anatase phase was 3 nm whereas it was 30 nm for rutile phase. Raman scattering experiments were also performed to confirm both anatase and rutile phases.

  19. Preparation of ultrafine LiTaO3 powders by citrate gel method

    Indian Academy of Sciences (India)

    S C Navale; V Samuel; V Ravi

    2005-08-01

    A gel was formed when a aqueous solution of Li(NO3), TaF5 and citric acid in stoichiometric ratio was heated in a water bath. This gel on decomposition at 700°C produced fine crystallites of ternary oxide, LiTaO3 (LT). The phase contents and lattice parameters were studied by powder X-ray diffraction (XRD). Particle size and morphology were studied by transmission electron spectroscopy (TEM).

  20. Microstructures of nanosized alumina powders synthesized by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    王晶; 张波

    2002-01-01

    The microstructures of nanosized alumina powders prepared by sol-gel routine were systematically studied with transmission electron microscopy and X-ray diffractometer. It was found that the morphologies of alumina gel powders change in the orders of caterpillar- thorn- granular-dumbbell shaped structures during calcining at temperatures from 20℃ to 800℃, 1200℃ and 1300℃. The caterpillar shaped structure composed of strings with a diameter of 5nm.

  1. Photochromic glass thin film formed by the sol-gel coating method

    Science.gov (United States)

    Nakazumi, Hiroyuki; Nagashiro, Rie; Matsumoto, Shinya; Isagawa, Kakuzoh

    1994-10-01

    The photochromic gel thin films using 1'-butyl-3',3'-dimethyl-6-nitro-spiro[2H-1- benzopyran-2,2'-indoline] (1) and 1'-butyl-spiro[2H-indole-2,3'- [3H]naphtho[2,1-b][1,4]oxazine] (2) dispersed in sol in the sol-gel processing were prepared and photochromic behaviors of these films were investigated. A good transparent coating layer on glass surface was formed in the range of ca. 6 - 10 wt% of 1 or 2 to alkoxysilane, and was colored by UV irradiation. The absorption band formed by UV-irradiation disappeared by thermal decay and also by Vis irradiation for 1. The thermal fading of the colored form to the spiro form 1 or 2 is dependent on a matrix of the gels, the colored forms in the film starting from methyltriethoxysilane (MTES), which is expected to include larger pores than in the film starting from tetraethoxysilane (TEOS) or silane oligomer, show faster thermal fading which roughly follows the first order kinetics. The colored form in the gel is stabilized, compared with that in solution or bulk gel, and it is suggested that there are some kinds of colored species in thin gel films containing spiropyran 1, which may be some aggregates, whereas only a colored species from spironaphthooxazine 2 is suggested. Photochromic behavior of 2 in sol was also examined.

  2. White-light emission of ZnO nanoparticles prepared by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    Li Shi-Shuai; Zhang Zhong; Hang Jin-Zhao; Feng Xiu-Peng; Liu Ru-Xi

    2011-01-01

    In:ZnO nanoparticles are prepared by the sol-gel process.The ratios of In/(Zn+In) are 0%,5%,8%,10%,and 15%,respectively.Crystal phase structures and optoelectronic properties of these samples are characterized and the chromaticity coordinates of different samples are also calculated in CIE-XYZ colour system.The results show that preferred growth direction of ZnO changes from (002) plane to (001) plane and interplanar distance becomes shorter.When the doping amount of In is 5%,Zn atoms are completely replaced by In atoms.The resistivities of the samples first decrease,then increase afterwards with the increase of the amount of In.With the increase of In,the ultraviolet emission is redshifted and new peaks occur at 465 nm,535 nm,and 630 nm.The sample with 10% indium has white-light emission.The band structures of samples with 0% and 12.5% indium are investigated by the first principle method.The mechanism of white emission is discussed from the viewpoint of additional energy levels.

  3. Fabrication and Optical Characterization of Zinc Oxide Nanoparticles Prepared via a Simple Sol-gel Method

    Directory of Open Access Journals (Sweden)

    K. Hedayati

    2015-10-01

    Full Text Available In this research zinc oxide (ZnO nano-crystalline powders were prepared by sol-gel method using zinc acetate. The ZnO nanoparticles were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM, ultraviolet-visible (UV-Vis, Fourier transform infra-red (FT-IR and energy dispersive X-ray (EDX spectroscopy. The structure of nanoparticles was studied using XRD pattern. The crystallite size of ZnO nanoparticles was calculated by Debye–Scherrer formula. Morphology of nano-crystals was observed and investigated using the SEM. The grain size of zinc oxide nanoparticles were in suitable agreement with the crystalline size calculated by XRD results. The optical properties of particles were studied with UV-Vis an FTIR absorption spectrum. The Raman spectrum measurements were carried out using a micro-laser Raman spectrometer forms the ZnO nanoparticles. At the end studied the effect of calcined temperature on the photoluminescence (PL emission of ZnO nanoparticles.

  4. Structural and multiferroic properties of barium substituted bismuth ferrite nanocrystallites prepared by sol-gel method

    Science.gov (United States)

    Anju; Agarwal, Ashish; Aghamkar, Praveen; Lal, Bhajan

    2017-03-01

    Nanocrystalline Bi1-xBaxFeO3 (0≤x≤0.3) multiferroics were efficiently obtained by sol-gel method after sintering at 800 °C for one hour. The Ba substitution in BiFeO3 (BFO) strongly modifies its structural and multiferroic properties. XRD studies revealed the structural transition from distorted rhombohedral (R3c) to pseudo-cubic (Pm3m) crystal symmetry. The magnetization increases appreciably for x=0.1, which is due to spin canting of magnetic moments at the nanoparticle surfaces and decreases afterward. From the temperature dependent magnetization studies, it is found that magnetic transition temperature (TN) is 620 K for x=0 and 640 K for x=0.1. Besides, the maximum polarisation value decreases with increasing Ba content. SEM micrographs revealed the formation of cubic nanocrystallites with increased porosity on Ba substitution. FTIR analysis of the samples also supports the structural change towards increased crystal symmetry.

  5. Synergic combination of the sol–gel method with dip coating for plasmonic devices

    Directory of Open Access Journals (Sweden)

    Cristiana Figus

    2015-02-01

    Full Text Available Biosensing technologies based on plasmonic nanostructures have recently attracted significant attention due to their small dimensions, low-cost and high sensitivity but are often limited in terms of affinity, selectivity and stability. Consequently, several methods have been employed to functionalize plasmonic surfaces used for detection in order to increase their stability. Herein, a plasmonic surface was modified through a controlled, silica platform, which enables the improvement of the plasmonic-based sensor functionality. The key processing parameters that allow for the fine-tuning of the silica layer thickness on the plasmonic structure were studied. Control of the silica coating thickness was achieved through a combined approach involving sol–gel and dip-coating techniques. The silica films were characterized using spectroscopic ellipsometry, contact angle measurements, atomic force microscopy and dispersive spectroscopy. The effect of the use of silica layers on the optical properties of the plasmonic structures was evaluated. The obtained results show that the silica coating enables surface protection of the plasmonic structures, preserving their stability for an extended time and inducing a suitable reduction of the regeneration time of the chip.

  6. Synthesis of ZnSnO{sub 3} nanostructure by sol gel method

    Energy Technology Data Exchange (ETDEWEB)

    Para, Touseef Ahmad; Reshi, Hilal Ahmad; Shelke, Vilas, E-mail: drshelke@gmail.com [Novel Materials Research Laboratory, Department of Physics, Barkatullah University, Bhopal, 462026 (India)

    2016-05-23

    Zinc Stannate (ZST) with composition ZnSnO{sub 3} is known for high electron mobility, optical, piezoelectric and charge storage properties. ZST crystalizes in different lattice structures, which allows a wide range of tunablity. We demonstrate successful synthesis of ZnSnO{sub 3} nanomaterial by sol-gel method. ZnSnO{sub 3} nanomaterials were calcined and sintered at different temperatures. Powder X-ray diffraction confirmed the single phase of the nanomaterial with rhombohedral R-3 space group. The Rietveld refinement of diffraction pattern yielded lattice parameter values a=5.26Å, c=14.09Å. Raman spectroscopy revealed higher activity towards higher wavenumbers. Raman shift around 530cm{sup −1} was found to be highly structure dependent, most probably due to anharmonic atomic vibrations in ZnO{sub 6}/SnO{sub 6} octahedra around center of mass. Sharp Peak around 650cm{sup −1} is characteristic of ZnSnO{sub 3} molecule.

  7. Synthesis and characterization of pyrochlore-type yttrium titanate nanoparticles by modified sol–gel method

    Indian Academy of Sciences (India)

    Z S Chen; W P Gong; T F Chen; S L Li

    2011-06-01

    Pyrochlore-type yttrium titanate (Y2Ti2O7) nanoparticles were successfully synthesized by a simple soft-chemistry technique viz. citric acid sol–gel method (CAM). The preparation process was monitored by X-ray diffraction, thermogravimetric–differential thermal analysis and Fourier transform–infrared experiments and the microstructures and average size of as-prepared products were characterized by transmission electron microscopy and high resolution transmission electron microscopy images. It was found that compared with traditional solid state reaction (SSR), Y2Ti2O7 nanopowders were synthesized at a relatively low temperature (750°C) for shortened reaction time. Detailed analysis showed that the as-prepared Y2Ti2O7 with good dispersibility and narrow size distribution were quasi-spherical; the average size was about 20–30 nm, also, the obtained products had higher BET surface area (50 m2/g). These properties are very helpful for a photocatalyst to achieve excellent activity and may result in better behaviour in hydrogen storage.

  8. AFM and XPS Study of Glass Surface Coated with Titania Nanofilms by Sol-Gel Method

    Science.gov (United States)

    Ji, Guo-Jun; Shi, Zhi-Ming

    2010-09-01

    Ce3+ -doped and undoped TiO2 nanofilms are prepared on glass surface using a sol-gel method. Crystal structure, surface morphology, chemical composition and element distribution of both glass substrates and TiO2 films were characterized by x-ray diffractometer (XRD), atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS). The XRD results indicate that the Ce3+-doped TiO2 films are solely composed of the anatase phase whereas in the undoped films a small amount of the rutile phase of TiO2 is present. AFM observations show that there exist many micro-cracks and micro-holes on glass substrate surface. In contrast, the surface of pure titania films is crack-free and the average crystallite size of the films is less than 50 nm. For the films doped with Ce3+, not only does it appear to be more uniform and compact, but also the corresponding crystal size is decreased. XPS results indicate that element interdiffusion occurs between the titania nanofilm and the glass substrate during the sintering process. The film is firmly adhered onto the glass surface through the chemical combination of Ti-O-Si bonds, and the combination is more enhanced by Ce3+-doping.

  9. Structural and electrical properties of lithium cobalt nanoferrites prepared by sol-gel method

    Science.gov (United States)

    Maisnam, Victory; Maisnam, Mamata; Phanjoubam, Sumitra

    2015-01-01

    Lithium cobalt nanoferrites having the compositional formula Li0.5-x/2CoxFe2.5-x/2O4 with x varying from 0.00 to 0.12 in steps of 0.03 were prepared by the chemical sol-gel method. Samples were heated at two different temperatures namely 300°C and 500°C for 4 h. Structural characterization of the samples was done using X-ray diffraction (XRD) technique and confirmed the formation of single phase with spinel structure in all the samples. From the XRD data, the lattice parameter was calculated and found to range from 82.87-83.35 nm while the crystallite size was found to be in the range 17-34 nm. Microstructural studies were carried out using the Scanning Electron Microscopy and revealed the microstructures with grain size ranging from 35-70 nm. Electrical properties like dielectric constant, dielectric loss and AC conductivity for these nanoferrites were investigated. The frequency variation of room temperature dielectric constant, dielectric loss and AC conductivity were studied in the frequency range 100 Hz-1 MHz, and a dispersive behavior was observed, which has been attributed to the Maxwell-Wagner type of interfacial polarization.

  10. Synthesis and Characterization of Microwave Absorber SiO2 by Sol-Gel Methode

    Science.gov (United States)

    Wardiyati, S.; Adi, W. A.; Deswita

    2017-05-01

    In recent years, information technology is growing rapidly, such as communication devices. However, there are still many shortcomings, for example, confidential information leaks caused by the leakage of electromagnetic waves used. A coating of electromagnetic materials or formation composite of electromagnetic material with other materials such as SiO2 is needed to overcome these problems. For such needs, it is necessary to study the manufacture of SiO2 which is simple, cheap, and effective. In this research, manufacture of SiO2 by sol-gel method used a solution of sodium silicate (Na2SiO3) as precursors and H2SO4 as a catalyst. The parameters tested in this experiment is the effect of sintering temperature on the properties of the resulting SiO2. The purpose of this study was to obtain an amorphous SiO2 powder, which is in nano-sized and has a high surface area. The characterization of prepared samples were performed by using an X-ray Diffraction (XRD), Fourier Transmission Infra Red (FTIR), Scanning electron microscopy-energy dispersive spectrometer (SEM-EDS), Transmission Electron Microscopy (TEM), and Surface Area Analyzer (SAA). Based on the experimental results, the SiO2 amorphous structure was obtained with a particle size of 15-20 nm, the surface area of 298 m2/g, and sintering temperature of 100 °C.

  11. Study of the Photoconductivity of Zinc Oxide Nanoparticles Synthesized by a Sol-Gel Method

    Science.gov (United States)

    Pandey, Nitin; Srivastava, Rajneesh Kumar

    2015-01-01

    ZnO nanoparticles (NPs) were synthesized by use of a sol-gel method at different temperatures, and characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-visible absorption spectroscopy. XRD analysis showed crystallite size was of the order of few tens of nanometers and the NPs had a wurtzite structure. SEM micrographs showed the NPs were pseudo-spherical in shape. UV-visible absorption study revealed a blue shift of the absorption edge compared with that of bulk ZnO. With increasing temperature of synthesis, the absorption edge was red-shifted. The photoconductivity, in air, of all the samples was studied. Variation of the dark current with applied voltage was linear for NPs synthesized at low temperatures and became super-linear for NPs synthesized at high temperatures. The dark current decreased with increasing temperature of synthesis. Photosensitivity was maximum for NPs synthesized at 600°C. Anomalous behavior, a decrease in photocurrent even during steady illumination, was observed for all the samples.

  12. Dielectric properties of FeNbO4 ceramics prepared by the sol-gel method

    Science.gov (United States)

    Devesa, S.; Graça, M. P.; Henry, F.; Costa, L. C.

    2016-11-01

    In this work, FeNbO4 powders were prepared using the sol-gel method. The fine powder particles were pressed into pellets and sintered at temperatures between 500 and 1200 °C. The powder was studied by X-ray diffraction and Raman spectroscopy. The morphology of the grains was investigated by scanning electron microscopy. Heat-treatment of the particles results in higher crystallinity, larger grains, and a decrease in the porosity of the material. The dielectric properties were measured in the frequency range of 102-106 Hz, in function of temperature (200-370 K). In all samples the real (ε‧) and imaginary (ε″) parts of the complex permittivity increase with increasing annealing temperature. The sample heat treated at 1200 °C shows the highest ε‧, > 104 at 300 K. All samples show a dielectric relaxation phenomenon, analysed using the modulus formalism. The evolution of the ac conduction activation energy and of the activation energy associated with the relaxation mechanism, is directly related with the changes promoted by the heat treatment in the structure and in the morphology of the base powders.

  13. Preparation and optical characteristics of ZnO films by chelating sol-gel method

    Institute of Scientific and Technical Information of China (English)

    YANG Lirong; JIN Zhengguo; BU Shaojing; SUN Yingchun; CHENG Zhijie

    2004-01-01

    The effect of different annealing temperatures on the structure, morphology, and optical properties of ZnO thin films prepared by the chelating sol-gel method was investigated. Zinc-oxide thin films were coated on quartz glass substrates by dip coating. Zinc nitrate, absolute ethanol, and citric acid were used as precursor, solvent, and chelating agent, respectively. The results show that ZnO films derived from zinc-citrate have lower crystallization temperature (below 400°C),and that the crystal structure is wurtzite. The films, treated over 500°C, consist of nano-particles and show to be porous at 600°C. The particle size of the film increases with the increase of the annealing temperature. The largest particle size is 60 nm at 600°C. The optical transmittances related to the annealing temperatures become 90% higher in the visible range. The film shows a starting absorption at 380 nm, and the optical band-gap of the thin film (fired at 500°C) is 3.25 eV and close to the intrinsic band-gap of ZnO (3.2 eV).

  14. Fabrication and characterization of Zinc Oxide (ZnO) nanoparticle by sol-gel method

    Science.gov (United States)

    Siswanto; Rochman, Nurul T.; Riski Akwalia, Putri

    2017-05-01

    Currently, nanomaterial is an interestingfield of study. This is due to its chemical and physical properties that are superior to that of large-sized materials. One nanomaterial widely studied is zinc oxide (ZnO). In this study, a synthesis of ZnO nanoparticles made by Sol-Gel method was conducted. The process parameters used are variations in pH, in increasing order, of 7; 8; 9; 10; 11; and 12. There are two principal reactions to produce a compound oxide, namely hydrolysis and condensation. NaOH is an agent for the hydrolysis of (CH3COO)2 Zn resultingin Zn (OH)2. Subsequently, condensation produces ZnO. Calcination was carried out at a temperature of 80°C for 1 hour. The ccharacterization of the samples showed that the condition of pH 12 produced the best sample with a size of 73.8 nm and ZnO percentage of 100%. Although pH 7 produced a particle size of 1.3 nm, the percentage of ZnO formed was only 42.9%. The calcination process was performed to remove CH3COONa. However, the process can lead to aggregation of ZnO particles to each other, which increases the particle size.

  15. Preparation of YBCO superconductor nanoparticles by sol-gel combustion method

    Directory of Open Access Journals (Sweden)

    M Farbod

    2010-09-01

    Full Text Available This paper describes the details of synthesizing nano crystalline YBCO superconductor using a sol-gel combustion method and the effect of sol pH and sintering temperature on particle size was investigated. The sintering temperature was chosen 880°C and the samples were annealed at this temperature for 5 hours. The morphology and structure of the nano scale products were characterized by powder X-ray diffraction and scanning electron microscopy. The results showed the samples prepared using the sol with pH of 5 and 7 have mean particle size of 500 and 200 nm, respectively. In order to investigate the effect of sintering temperature on the size of YBCO particles three sets of samples from the sol with pH of 7 were sintered at 800, 880 and 950°C. The results showed the samples sintered at 800, 880 and 950°C have the average particle size of 100, 200 and 400 nm respectively.

  16. Preparation of hydroxyapatite nanoparticles by sol-gel method with optimum processing parameters

    Energy Technology Data Exchange (ETDEWEB)

    Yusoff, Yusriha Mohd; Salimi, Midhat Nabil Ahmad; Anuar, Adilah [Universiti Malaysia Perlis, Kompleks Pusat Pengajian Jejawi 3, 02600 Arau, Perlis (Malaysia)

    2015-05-15

    Many studies have been carried out in order to prepare hydroxyapatite (HAp) by various methods. In this study, we focused on the preparation of HAp nanoparticles by using sol-gel technique in which few parameters are optimized which were stirring rate, aging time and sintering temperature. HAp nanoparticles were prepared by using precursors of calcium nitrate tetrahydrate, Ca(NO{sub 3}){sub 2}.4H{sub 2}O and phosphorous pentoxide, P{sub 2}O{sub 5}. Both precursors are mixed in ethanol respectively before they were mixed together in which it formed a stable sol. Fourier transform infrared (FTIR), X-ray diffraction (XRD) and Scanning electron microscopy (SEM) were used for its characterization in terms of functional group, phase composition, crystallite size and morphology of the nanoparticles produced. FTIR spectra showed that the functional groups that present in all five samples were corresponding to the formation of HAp. Besides, XRD shows that only one phase was formed which was hydroxyapatite. Meanwhile, SEM shows that the small particles combine together to form agglomeration.

  17. Characterization of Erbium Substituted Yttrium Iron Garnet Films Prepared by Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    Ramadan E. Shaiboub

    2014-01-01

    Full Text Available Yttrium iron garnet (YIG thin films substituted erbium ions (Er+3 Er0.4Y2.6Fe5O12 films were prepared by a sol-gel method at different temperatures which varied from 800 to 1000°C for 2 hours in air. Magnetic and microstructural properties of the films were characterized with X-ray diffraction (XRD, the field emission scanning electron microscopy (FESEM, and vibrating sample magnetometer (VSM. The XRD patterns of the sample have only peaks of the garnet structure. The lattice constants decrease, while the particle size increases from 51 to 85 nm as the annealing temperature increases with average in thickness of 300 nm. The saturation magnetization and the coercivity of the samples increased from 26 (emu/cc and 28 Oe for the film annealed at 800°C to 76 (emu/cc and 45 Oe for film annealed at 1000°C, respectively.

  18. Structural and optical properties of chromium doped zinc oxide nanoparticles synthesized by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Naqvi, Syed Mohd. Adnan, E-mail: adiaks2004@yahoo.co.in [Department of Fundamental and Applied Sciences, Universiti Teknologi Petronas, Bandar Seri Iskandar, Perak (Malaysia); Irshad, Kashif, E-mail: alig.kashif@gmail.com [Department of Mechanical Engineering, Universiti Teknologi Petronas, Bandar Seri Iskandar, Perak (Malaysia); Soleimani, Hassan, E-mail: hassan.soleimani@petronas.com.my, E-mail: noorhana-yahya@petronas.com.my; Yahya, Noorhana, E-mail: hassan.soleimani@petronas.com.my, E-mail: noorhana-yahya@petronas.com.my

    2014-10-24

    Nanosized Cr-doped ZnO nano particles were synthesized by facile sol-gel auto combustion method. The structural and optical properties of Cr-doped ZnO nanoparticles have been investigated by XRD and UV-Vis spectroscopy at room temperature for 0% to 8% concentration. X-ray diffraction analysis reveals that the Cr-doped ZnO crystallizes in a single phase polycrystalline nature with wurtzite lattice. With every % of doping, the peaks are shifting scarcely and doping of Cr is possible up to 7%. After that, the last peak vanishes, that signifies its structure is transmuted from 8% doping. The average crystallite size decreases with increase in Cr concentration (i.e. 28.9 nm for 0% to 25.8 nm for 8%). The UV-Vis spectra of the nanoparticles betoken an incrementation in the band gap energy from 3.401, 3.415, 3.431, 3.437,3.453, 3.514,3.521, 3.530 and 3.538 eV respectively, for 0,1, 2, 3, 4, 5, 6, 7 and 8 % doping concentration.

  19. Biodiesel production using alkali earth metal oxides catalysts synthesized by sol-gel method

    Directory of Open Access Journals (Sweden)

    Majid Mohadesi

    2014-03-01

    Full Text Available Biodiesel fuel is considered as an alternative to diesel fuel. This fuel is produced through transesterification reactions of vegetable oils or animal fat by alcohols in the presence of different catalysts. Recent studies on this process have shown that, basic heterogeneous catalysts have a higher performance than other catalysts. In this study different alkali earth metal oxides (CaO, MgO and BaO doped SiO2 were used as catalyst for the biodiesel production process. These catalysts were synthesis by using the sol-gel method. A transesterification reaction was studied after 8h by mixing corn oil, methanol (methanol to oil molar ratio of 16:1, and 6 wt. % catalyst (based on oil at 60oC and 600rpm. Catalyst loading was studied for different catalysts ranging in amounts from 40, 60 to 80%. The purity and yield of the produced biodiesel for 60% CaO/SiO2 was higher than other catalysts and at 97.3% and 82.1%, respectively.

  20. Synergic combination of the sol-gel method with dip coating for plasmonic devices.

    Science.gov (United States)

    Figus, Cristiana; Patrini, Maddalena; Floris, Francesco; Fornasari, Lucia; Pellacani, Paola; Marchesini, Gerardo; Valsesia, Andrea; Artizzu, Flavia; Marongiu, Daniela; Saba, Michele; Marabelli, Franco; Mura, Andrea; Bongiovanni, Giovanni; Quochi, Francesco

    2015-01-01

    Biosensing technologies based on plasmonic nanostructures have recently attracted significant attention due to their small dimensions, low-cost and high sensitivity but are often limited in terms of affinity, selectivity and stability. Consequently, several methods have been employed to functionalize plasmonic surfaces used for detection in order to increase their stability. Herein, a plasmonic surface was modified through a controlled, silica platform, which enables the improvement of the plasmonic-based sensor functionality. The key processing parameters that allow for the fine-tuning of the silica layer thickness on the plasmonic structure were studied. Control of the silica coating thickness was achieved through a combined approach involving sol-gel and dip-coating techniques. The silica films were characterized using spectroscopic ellipsometry, contact angle measurements, atomic force microscopy and dispersive spectroscopy. The effect of the use of silica layers on the optical properties of the plasmonic structures was evaluated. The obtained results show that the silica coating enables surface protection of the plasmonic structures, preserving their stability for an extended time and inducing a suitable reduction of the regeneration time of the chip.

  1. Comparative Studies on Detection of Antibodies against Infectious Bursal Disease Virus with Test Strips and Agar Gel Immunodiffusion Method

    Institute of Scientific and Technical Information of China (English)

    Jinliang ZHANG; Wentong ZHANG; Sishun HU; Dingren BI; Xiliang WANG; Yuncai XIAO

    2012-01-01

    [Objective] This study aimed to compare the detection results of antibodies against infectious bursal disease virus with test strips and agar gel immunodiffusion method. [Method] Antibodies against infectious bursal disease virus in chicken serum were detected using test strips developed in our laboratory, and the results were comparad~with that using traditional agar diffusion method. [Result] The comparative study of the two methods showed that the sensitivity of test strips was eight times over agar gel immunodiffusion; test strips showed higher detection rate in the deter- mination test of 216 clinical samples, with high specificity, easy preservation, and simple and rapid operation, thereby being more suitable for the monitoring of clinical antibodies. [Conclusion] Test strips could replace the existing serological methods, having great promotion and application value in antibody monitoring.

  2. Tranexamic acid combined with recombinant factor VIII increases clot resistance to accelerated fibrinolysis in severe hemophilia A

    DEFF Research Database (Denmark)

    Hvas, Anne-Mette; Sørensen, Hanne Thykjær; Norengaard, Lisbeth

    2007-01-01

    BACKGROUND: Most patients with severe hemophilia A suffer from a profoundly compromised hemostatic response. In addition to both the delayed and slow development of a clot, previous studies have documented that severe hemophilia A is also associated with reduced clot stability. OBJECTIVES: We...... examined whether the clot stability in hemophiliacs could be improved by treatment with tranexamic acid (TXA) in combination with recombinant factor VIII (rFVIII). PATIENTS/METHODS: Baseline blood samples were obtained from eight males with severe hemophilia A. Thereafter, a bolus injection of r...... the elasticity curve increased 5-fold after rFVIII and 24-fold after addition of TXA. CONCLUSIONS: The study demonstrates that simultaneous treatment with TXA and rFVIII significantly improves the clot stability in patients with hemophilia A. Udgivelsesdato: December...

  3. Formulation and evaluation of Thiocolchicoside Topical Gel by using different method

    Directory of Open Access Journals (Sweden)

    Ramesh Amarsing Rathod

    2016-03-01

    Full Text Available Thiocolchicoside used for the effective treatment of muscle spasm, cramps, musculoskeletal and neuromuscular disorders. It is available in market in the form of capsules and injection. The major problem associated with thiocolchicoside is it's bioavailability which is very low i.e. 25-30% only so in order to minimize drug loss due to first pass metabolism, and overcome problem associated with low bioavailability of drug there is a need to formulate semisolid preparation in the form of gel so we try to formulate and evaluate thiocolchicoside gel using different polymer and comparative study of their drug release.In vitro release of thiocolchicoside gel from three different polymers i.e. carbapol, HPMC, and Na CMC to an aqueous receptor phase through goat skin was monitored spectrophotometrically at a wavelength of 259nm. This study was conducted to develop gel formulation of thiocolchicoside using three types of gelling agent i.e. carbopol, HPMC, Na CMC. Effect of penetration enhancer (propylene glycol on the release has been studied.   The gels were evaluated for physical appearance, rheological behaviour, drug release, and stability. Drug release from all gelling agent through goat skin was evaluated using keshary-chien diffusion cell.All gels show acceptable physical properties concerning colour, homogenity, consistancy spredability and pH value. Among all gel formulation carbapol  showed superior drug release then followed by Na CMC and HPMC. Drug release decreased with increased in the polymer concentration. Drug release was not linearly proportional with the conc. of penetration enhancer or co-solvent stability studies showed that the physical appearance, rheological properties and drug release remained unchanged upon storage for two month at ambient condition.

  4. Barium titanate ceramic inks for continuous ink-jet printing synthesized by mechanical mixing and sol-gel methods

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zhen-jun; YANG Zheng-fang; YUAN Qi-ming

    2008-01-01

    Ink-jet printing of ceramic thick films is one of low cost on-site ceramic pattern fabrication methods. It is necessary to investigate the rheological behaviour of ceramic inks and drying behaviour of droplets. Two kinds of BaTiO3 ceramic inks were prepared by mechanical mixing and sol-gel methods, respectively. The effect of preparation parameters, such as quantity of polyacrylic acid(PAA) and solid content, on physicochemical and rheologic properties of the ceramic inks was investigated. The results show that they satisfy the requirements of continuous ink-jet printing. The appearances of printed dots and single printed layers were observed by SEM. The SEM images indicate that dots printed with mixing method ink are in ring shape, and dots printed with sol-gel method ink are in pancake shape, so the printed layer surface with the latter ink is smoother. The causes of these phenomena were discussed.

  5. Structural and Electrical Properties of Li–Ni Nanoferrites Synthesised by Citrate Gel Autocombustion Method

    Directory of Open Access Journals (Sweden)

    G. Aravind

    2014-01-01

    Full Text Available An attempt has been made to synthesize nanocrystalline lithium-nickel ferrites with a compositional formula Li0.5−0.5xNixFe2.5−0.5xO4 (where x=0.0 to 1.0 with step of 0.2 by a low temperature citrate gel autocombustion method. Single phase cubic structure is confirmed by X-ray diffraction analysis. This result demonstrates that the prepared samples are homogeneous and the sharp peaks reveal that the samples are in good crystalline form. As the Ni concentration is increased, various interesting changes in the values of the structural parameters like lattice parameter, X-ray density, bulk density, and porosity have been observed. The surface morphology of the prepared samples was studied using scanning electron microscopy (SEM. The DC resistivity measurements were carried out using two-probe method from 200°C to 600°C. The variation of log⁡(σT with reciprocal of temperature shows a discontinuity at Curie temperature. log⁡(σT versus 1/T plot of the pure lithium ferrites is almost linear which indicates the Curie temperature of the pure lithium ferrites was beyond our measured temperature. The dielectric properties of these ferrites have been studied using a LCR meter from the room temperature to 700 K at various frequencies up to 5 MHz, which reveals that all the prepared samples have dielectric transition temperature around 600 K.

  6. Comparison of in vitro dialysis release methods of loperamide-encapsulated liposomal gel for topical drug delivery

    Directory of Open Access Journals (Sweden)

    Hua S

    2014-01-01

    Full Text Available Susan HuaThe School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW, AustraliaBackground: The purpose of this study was to determine the most appropriate dialysis equilibrium method to assess liposomal gel formulations containing hydrophobic drugs, to give the most accurate indication of drug release.Methods: Loperamide hydrochloride-encapsulated liposomes, composed of L-α-phosphatidylcholine and cholesterol (molar ratio of 2:1, were prepared according to the method of dried lipid film hydration. The liposomes were incorporated into a carbopol gel (0.5%, weight/weight. The release of the drug from the nanoparticles was assessed using a number of variations of the dialysis technique, taking into account solubility parameters and formulation. Method 1 (below saturation point and Method 2 (above saturation point used a dilution method to evaluate how drug concentration and solubility affects the in vitro drug-release profile of loperamide hydrochloride, while Methods 3 (below saturation point and 4 (above saturation point evaluated how drug concentration and the gel base affect the release profile.Results: In Method 1, the liposomes showed a rapid release of just over 60% in the first 3 hours and then a slower, sustained release to just over 70% at 24 hours. Method 2 showed a gradual, sustained release profile with the liposomes with 55% release at 24 hours. In Method 3, the liposomes showed a rapid burst release of 98% at 2 hours. In Method 4, the liposomal gel had a rapid release of 60% within 3 hours and then a more gradual, sustained release with 86% release at 24 hours. The free drug suspension in Methods 2 and 4 showed a limited release across the dialysis membrane, in comparison to Methods 1 and 3, which showed a complete release in a timely manner.Conclusion: This study has demonstrated that the actual method used for equilibrium dialysis plays a significant role in determining the true characteristics of a

  7. Study of hafnium (IV) oxide nanoparticles synthesized by polymerized complex and polymer precursor derived sol-gel methods

    KAUST Repository

    Ramos-González, R.

    2010-03-01

    This work reports the preparation and characterization of hafnium (IV) oxide (HfO2) nanoparticles grown by derived sol-gel routes that involves the formation of an organic polymeric network. A comparison between polymerized complex (PC) and polymer precursor (PP) methods is presented. For the PC method, citric acid (CA) and ethylene glycol (EG) are used as the chelating and polymerizable reagents, respectively. In the case of PP method, poly(acrylic acid) (PAA) is used as the chelating reagent. In both cases, different precursor gels were prepared and the hafnium (IV) chloride (HfCl4) molar ratio was varied from 0.1 to 1.0 for the PC method and from 0.05 to 0.5 for the PP method. In order to obtain the nanoparticles, the precursors were heat treated at 500 and 800 °C. The thermal characterization of the precursor gels was carried out by thermogravimetric analysis (TGA) and the structural and morphological characterization by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD patterns of the samples obtained by both methods shows the formation of HfO2 at 500 °C with monoclinic crystalline phase. The PC method exhibited also the cubic phase. Finally, the HfO2 nanoparticles size (4 to 11 nm) was determined by TEM and XRD patterns. © (2010) Trans Tech Publications.

  8. Method for the typing of Clostridium difficile based on polyacrylamide gel electrophoresis of (/sup 35/S)methionine-labeled proteins

    Energy Technology Data Exchange (ETDEWEB)

    Tabaqchali, S.; O' Farrell, S.; Holland, D.; Silman, R.

    1986-01-01

    A typing method for Clostridium difficile based on the incorporation of (/sup 35/S)methionine into cellular proteins, their separation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and their visualization by autoradiography is described. On analysis of the radiolabeled-protein profiles, nine distinct groups were observed (A to E and W to Z). The method, which is simple, reproducible, and readily expandable, has been applied in epidemiological studies to demonstrate cross-infection and hospital acquisition of C. difficile.

  9. Preparation and studies of Co(II) and Co(III)-substituted barium ferrite prepared by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Teh, Geok Bee [Department of Bioscience and Chemistry, Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, 53300 Kuala Lumpur (Malaysia)]. E-mail: tehgb@mail.utar.edu.my; Nagalingam, Saravanan [Department of Bioscience and Chemistry, Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, 53300 Kuala Lumpur (Malaysia); Jefferson, David A. [Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW (United Kingdom)

    2007-01-15

    The sol-gel preparative method was employed to synthesise Co(II) and Co(III)-substituted barium ferrite. This method was attempted to achieve higher homogeneity of the final product. Samples of substituted ferrites were characterised by various experimental techniques including high resolution transmission electron microscopy, X-ray diffraction analysis, magnetometry and thermal gravimetric analysis. The microstructural changes induced by such substitution are also discussed.

  10. The activated clotting time in cardiac surgery : Should Celite or kaolin be used?

    NARCIS (Netherlands)

    De Vries, Adrianus J.; Lansink-Hartgring, Annemieke Oude; Fernhout, Freek-Jan; Huet, Rolf C. G.; van den Heuvel, Edwin R.

    OBJECTIVES: Both kaolin- and Celite-activated clotting times (ACT) are used to guide anticoagulation during cardiopulmonary bypass. It is unknown whether these methods lead to similar management procedures for anticoagulation in patients and are thus interchangeable in terms of bias, precision and

  11. Biocompatibility of glass-crystalline materials obtained by the sol-gel method: effect on macrophage function.

    Science.gov (United States)

    Turyna, B; Milc, J; Laczka, A; Cholewa, K; Laczka, M

    1996-07-01

    The aim of this work was to confirm in vitro biocompatibility of a new gel-derived glass-crystalline material containing hydroxyapatite and wollastonite phases. For the purpose of comparison, studies were also carried out for a material of the same chemical composition obtained by the traditional melting method. We examined the behaviour and response of cells cultured in the presence of the studied materials. The level of activation of macrophages in culture was determined using three different methods: measurement of respiratory burst by chemiluminescence, nitrite assay and by bioassay of secreted cytokines after immunoelectrophoresis of acute phase proteins from hepatoma cells. All our results show a relatively low, close to control level, activation of macrophages exposed to the studied materials. This indicates a good biocompatibility of both the gel-derived material and the material obtained by the traditional melting method.

  12. Development of durable self-cleaning coatings using organic-inorganic hybrid sol-gel method

    Science.gov (United States)

    Kumar, Divya; Wu, Xinghua; Fu, Qitao; Ho, Jeffrey Weng Chye; Kanhere, Pushkar D.; Li, Lin; Chen, Zhong

    2015-07-01

    Self-cleaning coatings with excellent water-repellence and good mechanical properties are in high demand. However, producing such coatings with resistance to mechanical abrasion and environmental weathering remains a key challenge. Mechanically robust coatings based on tetraethylorthosilicate (TEOS) and glycidoxypropyltriethoxysilane (Glymo) have been prepared using a sol-gel method. Emphasis is given to the addition of Glymo, an epoxy silane which creates an organic matrix that blends with the inorganic Sisbnd Osbnd Si matrix formed from the TEOS. The combination of the blended matrix produced coatings with good adhesion to substrates and improved mechanical properties. Fluoroalkylsilane (FAS) and silica fillers were introduced to increase the hydrophobicity of the coating. It was found that the water contact angle (CA) of these coatings increases from 115° to 164° upon decreasing filler size from 1-5 μm to 10-20 nm. The sliding angle (SA) for coatings with 15 wt.% loading of 10-20 nm silica is around 2°. UV weathering does not show significant effect on the properties of the coatings. Mechanical properties and performances including hardness, Young's modulus, coating adhesion and abrasion resistance were systematically analyzed. In the current work, a simple self-cleaning test, which measures the extent of dirt accumulation and subsequent removal by water spray, was performed. The coatings with 15 wt.% loading of 10-20 nm silica particles show the best self-cleaning performance both before and after mechanical abrasion. The developed coating process is simple and can be easily scaled-up for large surfaces that require self-cleaning function.

  13. Characterization of nanocrystalline ZnO:Al films by sol-gel spin coating method

    Energy Technology Data Exchange (ETDEWEB)

    Gareso, P. L., E-mail: pgareso@gmail.com; Rauf, N., E-mail: pgareso@gmail.com; Juarlin, E., E-mail: pgareso@gmail.com [Department of Physics, Faculty of Mathematics and Natural Sciences, Hasanuddin University, Makassar 90245 (Indonesia); Sugianto,; Maddu, A. [Department of Physics, Faculty of Mathematics and Natural Sciences, Bogor Institute of Culture, IPB Bogor (Indonesia)

    2014-09-25

    Nanocrystalline ZnO films doped with aluminium by sol-gel spin coating method have been investigated using optical transmittance UV-Vis and X-ray diffraction (X-RD) measurements. ZnO films were prepared using zinc acetate dehydrate (Zn(CH{sub 3}COO){sub 2}@@‡2H{sub 2}O), ethanol, and diethanolamine (DEA) as a starting material, solvent, and stabilizer, respectively. For doped films, AlCl{sub 3} was added to the mixture. The ZnO:Al films were deposited on a transparent conductive oxide (TCO) substrate using spin coating technique at room temperature with a rate of 3000 rpm in 30 sec. The deposited films were annealed at various temperatures from 400°C to 600°C during 60 minutes. The transmittance UV-Vis measurement results showed that after annealing at 400°C, the energy band gap profile of nanocrystalline ZnO:Al film was a blue shift. This indicated that the band gap of ZnO:Al increased after annealing due to the increase of crystalline size. As the annealing temperature increased the bandgap energy was a constant. In addition to this, there was a small oscillation occurring after annealing compared to the as–grown samples. In the case of X-RD measurements, the crystalinity of the films were amorphous before annealing, and after annealing the crystalinity became enhance. Also, X-RD results showed that structure of nanocrystalline ZnO:Al films were hexagonal polycrystalline with lattice parameters are a = 3.290 Å and c = 5.2531 Å.

  14. Optimization of a reliable, fast, cheap and sensitive silver staining method to detect SSR markers in polyacrylamide gels

    Directory of Open Access Journals (Sweden)

    Mergeai G.

    2006-01-01

    Full Text Available A reliable, fast, cheap and sensitive silver staining method to detect nucleic acids in polyacrylamide gels was developed from two standard stain procedures. The main differences between the three methods concerned (i the preexposure with formaldehyde during silver nitrate impregnation, (ii the addition of sodium thiosulfate and sodium carbonate instead of sodium hydroxide during development; (iii the removal of the stop reaction or the inclusion of absolute ethanol with acetic acid in the stop solution and (iv the duration of the different reaction steps. All methods allowed the detection of similar polymorphisms for single sequence repeats with different cotton genotypes but important differences regarding the contrast, background and conservation duration of the gels were observed. Two methods gave superior sensitivity. The improved method was sensitive, fast (20 min, gave lower backgrounds, produced gels with long-term conservation ability, and allowed a reutilization of all the solutions used in the staining procedure from fi ve to seven times, making it quite cheap.

  15. THE ACTION OF CHLORINATED ANTISEPTICS ON BLOOD CLOT

    Science.gov (United States)

    Taylor, Herbert D.; Stebbins, Marianne G.

    1919-01-01

    This work demonstrates that the chlorinated antiseptics have no power to penetrate blood clots and destroy bacteria therein contained. Correspondingly, blood clots may protect virulent bacteria for a long period of time and the organisms properly planted will be able to proliferate in a normal manner. PMID:19868298

  16. Photocatalytic degradation of methylene blue dye by zinc oxide nanoparticles obtained from precipitation and sol-gel methods.

    Science.gov (United States)

    Balcha, Abebe; Yadav, Om Prakash; Dey, Tania

    2016-12-01

    Zinc oxide (ZnO) nanoparticles were synthesized by precipitation and sol-gel methods. The aim of this study was to understand how different synthetic methods can affect the photocatalytic activity of ZnO nanoparticles. As-synthesized ZnO nanoparticles were characterized by X-ray diffraction (XRD) and UV-Visible spectroscopic techniques. XRD patterns of ZnO powders synthesized by precipitation and sol-gel methods revealed their hexagonal wurtzite structure with crystallite sizes of 30 and 28 nm, respectively. Their photocatalytic activities were evaluated by photocatalytic degradation of methylene blue, a common water pollutant, under UV radiation. The effects of operational parameters such as photocatalyst load and initial concentration of the dye on photocatalytic degradation of methylene blue were investigated. While the degradation of dye decreased over the studied dye concentration range of 20 to 100 mg/L, an optimum photocatalyst load of 250 mg/L was needed to achieve dye degradation as high as 81 and 92.5 % for ZnO prepared by precipitation and sol-gel methods, respectively. Assuming pseudo first-order reaction kinetics, this corresponded to rate constants of 8.4 × 10(-3) and 12.4 × 10(-3) min(-1), respectively. Hence, sol-gel method is preferred over precipitation method in order to achieve higher photocatalytic activity of ZnO nanostructures. Photocatalytic activity is further augmented by better choice of capping ligand for colloidal stabilization, starch being more effective than polyethylene glycol (PEG).

  17. Catalytic activity of acid and base with different concentration on sol-gel kinetics of silica by ultrasonic method.

    Science.gov (United States)

    Das, R K; Das, M

    2015-09-01

    The effects of both acid (acetic acid) and base (ammonia) catalysts in varying on the sol-gel synthesis of SiO2 nanoparticles using tetra ethyl ortho silicate (TEOS) as a precursor was determined by ultrasonic method. The ultrasonic velocity was received by pulsar receiver. The ultrasonic velocity in the sol and the parameter ΔT (time difference between the original pulse and first back wall echo of the sol) was varied with time of gelation. The graphs of ln[ln1/ΔT] vs ln(t), indicate two region - nonlinear region and a linear region. The time corresponds to the point at which the non-linear region change to linear region is considered as gel time for the respective solutions. Gelation time is found to be dependent on the concentration and types of catalyst and is found from the graphs based on Avrami equation. The rate of condensation is found to be faster for base catalyst. The gelation process was also characterized by viscosity measurement. Normal sol-gel process was also carried out along with the ultrasonic one to compare the effectiveness of ultrasonic. The silica gel was calcined and the powdered sample was characterized with scanning electron microscopy, energy dispersive spectra, X-ray diffractogram, and FTIR spectroscopy.

  18. Epitaxial growth of ZnO on quartz substrate by sol-gel spin-coating method

    Science.gov (United States)

    Chebil, W.; Boukadhaba, M. A.; Fouzri, A.

    2016-07-01

    ZnO thin films grown on Quartz substrates using sol-gel method were synthesized and annealing at different temperature (700 °C, 900 °C and 1000 °C). The structural, optical and morphological comparison of ZnO layers elaborated with that obtained by the sophisticated and expensive technique MOCVD demonstrates the success of the ZnO epitaxial growth on quartz substrate by sol-gel process. Sol-gel ZnO film deposited on quartz substrate annealed at 1000 °C exhibit only (00l) XRD peak which is similar to the diffraction patterns of epitaxial ZnO grown on sapphire by MOCVD. The Surface morphology was examined by SEM which revealed that the grain size becomes larger and faceted as increasing annealing temperature. Pl emission peak of sol-gel ZnO annealed at 1000 °C revealed a close similarity with that obtained by MOCVD ZnO but with a weaker intensity.

  19. Altered plasma fibrin clot properties in essential thrombocythemia.

    Science.gov (United States)

    Małecki, Rafał; Gacka, Małgorzata; Kuliszkiewicz-Janus, Małgorzata; Jakobsche-Policht, Urszula; Kwiatkowski, Jacek; Adamiec, Rajmund; Undas, Anetta

    2016-01-01

    Patients with increased thromboembolic risk tend to form denser fibrin clots which are relatively resistant to lysis. We sought to investigate whether essential thrombocythemia (ET) is associated with altered fibrin clot properties in plasma. Ex vivo plasma fibrin clot permeability coefficient (Ks), turbidimetry and clot lysis time (CLT) were measured in 43 consecutive patients with ET (platelet count from 245 to 991 × 10(3)/µL) and 50 control subjects matched for age, sex and comorbidities. Fibrinolysis proteins and inhibitors together with platelet activation markers were determined. Reduced Ks (-38%, p Ks inversely correlated with fibrinogen, PF4 and C-reactive protein. CLT positively correlated only with PAI-1. Patients with ET display prothrombotic plasma fibrin clot phenotype including impaired fibrinolysis, which represents a new prothrombotic mechanism in this disease.

  20. An evaluation of the SPIFE 3000 semi-automated gel electrophoresis system for the identification of hemoglobin variants and comparison of relative electrophoretic mobilities with manual gel electrophoresis methods.

    Science.gov (United States)

    Hoyer, J D; Markley, K M; Savedra, M E; Kubik, K S; Scheidt, R M

    2010-06-01

    Laboratory identification of hemoglobin (Hb) variants can involve multiple techniques. The use of semi-automated instruments that perform gel electrophoresis and staining, such as the SPIFE 3000 electrophoresis system, can greatly reduce the labor required for these commonly used techniques. We performed a comparison of the method involved in SPIFE 3000 system with those of manual gel electrophoresis. A total of 22 540 samples were analyzed using the SPIFE 3000, and compared with mobilities on cellulose acetate and citrate agar gels using standard manual methods. The results were compared using relative electrophoretic mobilities (REM). Of the 191 Hb variants identified, only 13 had REM that differed from manual electrophoresis when analyzed using the SPIFE 3000 system. One variant (Hb O-Indonesia) showed different mobility on both acid and alkaline gels, two (Hb E, Hb Sunshine Seth) on alkaline gel only, and 10 (Hbs N-Baltimore, N-Seattle, O-Arab, Shelby, Summer Hill, Tak, Hasharon, M-Iwate, Q-Iran, and Setif) on acid gels only. The SPIFE 3000 semi-automated electrophoresis system produces similar results when compared with those of standard manual electrophoresis methods.

  1. Growth of hydroxyapatite on physiologically clotted fibrin capped gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sastry, T P; Sundaraseelan, J; Swarnalatha, K; Sobhana, S S Liji; Makheswari, M Uma; Sekar, S; Mandal, A B [Central Leather Research Institute, Chennai-600020, Tamilnadu (India)], E-mail: sastrytp@hotmail.com, E-mail: abmandal@hotmail.com

    2008-06-18

    The growth of hydroxyapatite (HAp) on physiologically clotted fibrin (PCF)-gold nanoparticles is presented for the first time by employing a wet precipitation method. Fourier transform infrared (FTIR) spectroscopy confirmed the characteristic functionalities of PCF and HAp in the PCF-Au-HAp nanocomposite. Scanning electron microscopy (SEM) images have shown cuboidal nanostructures having a size in the range of 70-300 nm of HAp, whereas 2-50 nm sized particles were visualized in high-resolution transmission electron microscopy (TEM). Energy-dispersive x-ray (EDX) and x-ray diffraction (XRD) studies have confirmed the presence of HAp. These results show that gold nanoparticles with PCF acted as a matrix for the growth of HAp, and that PCF-Au-HAp nanocomposite is expected to have better osteoinductive properties.

  2. Preparation and magnetic properties of Fe2O3 microtubules prepared by sol-gel template method

    Institute of Scientific and Technical Information of China (English)

    CHANG Chuanbo; ZHANG Cunrui; WANG Wenyan; LI Qiaoling

    2010-01-01

    Fe(OH)3 precursor sol was prepared by a sol-gel method.The precursor sol was dipped onto the absorbent cotton,and gel was formed on the absorbent cotton template after the volatilization of moisture.Fe2O3 microtubules were synthesized after the process of self-propagation or calcination.The phase,morphology,and particle diameter of the samples were examined by X-ray diffraction(XRD)and scanning electron microscopy(SEM),and the magnetic properties of the samples were measured using a vibrating sample magnetometer(VSM).The external diameters of Fe2O3 microtubules ranged between 8 and 13 μm,and the wall thicknesses ranged between 0.5 and 2 μm The type of the calcination method plays a significant role in developing the Fe2O3 phase and the variation in the magnetic properties in the sol-gel template complexing method.γ-Fe2O3 was synthesized by a self-propagation method.However,α-Fe2O3 was synthesized after calcination at 400℃ for 2 h.The coercivity of the samples synthesized by calcination at 400℃ for 2 h after self-propagation was found to increase significantly,thereby presenting hard magnetic properties.

  3. Method for the quantitation of gastric emptying time of gel test meals.

    Science.gov (United States)

    Russell, J; Bass, P

    1984-09-01

    Isotopic markers were developed to allow measurement of the gastric emptying times of homogeneous and nonhomogeneous gel meals. Meals containing the dietary fibers psyllium and guar gum presented as homogeneous, viscous gels while meals containing the synthetic polymer polycarbophil presented as discrete gel particle-water mixtures. Fiber meals were labeled differently than polycarbophil meals. Fiber meals were labeled with 51Cr-CM-Sephadex. The marker was uniformly suspended in meals containing at least 1% guar or 2% psyllium. In contrast, polycarbophil particles were labeled by hydrating the dried granules with saline in which Na2(51)CrO4 had been dissolved. Use of the markers to measure gastric emptying was demonstrated in dogs fitted with duodenal cannulas. Half of the fiber meals emptied from the stomach in about 40 min without significant dilution by secretions. In contrast, only 8% of the polycarbophil particles emptied by 90 min. Particle-specific labeling of polycarbophil was important because the meal effluent was diluted extensively by secretions. We conclude that 51Cr-CM-Sephadex and soluble Cr-51 may be used as meal markers for estimation of the gastric emptying times of certain homogeneous and nonhomogeneous gel-type meals, respectively.

  4. Preparation and Characterization of Titania-silica Composite Particles by Pechini Sol-gel Method

    Directory of Open Access Journals (Sweden)

    Wu Yuanting

    2016-01-01

    Full Text Available Two Pechini sol-gel processes were used to prepare titania-silica composite particles. The dynamic oxidation behavior of the TiO2-SiO2 powders has been characterized by thermogravimetry-differential scanning calorimetry (TG-DTG-DSC. The crystal phase and microstructure of the composite particles were investigated by X-ray diffraction (XRD and field emission scanning electron microscope (FE-SEM. The effects of Si:Ti molar ratio and sol-gel process on the TiO2-SiO2 powders were studied. The preparation of the polymeric precursors can influence the morphology of obtained TiO2-SiO2 composite particles. The spherical TiO2-SiO2 composite particles which are 20 nm~400 nm in diameter appear in gel-1 system. However, the TiO2-SiO2 powders obtained by gel-2 system are irregular in shape and 2~15 μm in diameter which show a loose porous structure consisted of very fine granules.

  5. Sintering and microstructure of silicon carbide ceramic with Y3Al5O12 added by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    GUO Xing-zhong; YANG Hui

    2005-01-01

    Silicon carbide (SiC) ceramic with YAG (Y3Al5O12) additive added by sol-gel method was liquid-phase sintered at different sintering temperatures, and the sintering mechanism and microstructural characteristics of resulting silicon carbide ceramics were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and elemental distribution of surface (EDS). YAG (yttrium aluminum garnet) phase formed before the sintering and its uniform distribution in the SiC/YAG composite powder decreased the sintering temperature and improved the densification of SiC ceramic. The suitable sintering temperature was 860 ℃ with the specimen sintered at this temperature having superior sintering and mechanical properties, smaller crystal size and fewer microstructure defects. Three characteristics of improved toughness of SiC ceramic with YAG added by sol-gel method were microstructural densification, main-crack deflection and crystal ‘bridging'.

  6. Investigation of the effect of kaolin and tissue factor-activated citrated whole blood, on clot forming variables, as evaluated by thromboelastograph

    DEFF Research Database (Denmark)

    Johansson, Per Ingemar; Bochsen, L.; Andersen, S.

    2008-01-01

    laboratory-based analysis, however, requires validation of the activators employed and the effect of storage of the WB sample in citrate before analysis. STUDY DESIGN AND METHODS: The effect of kaolin, tissue factor (TF) 1:17,000, or TF 1:42,500 on TEG clotting time (R), Angle (velocity of clot formation......), and maximum clot strength (amplitude [MA]) were evaluated, together with day-to-day variation, the coefficient of variance (CV%), and the effect of citrate storage time. RESULTS: Clot formation variables were equally affected by TF 1:17,000 and kaolin activation, whereas R was significantly longer when TF 1...... minutes were evaluated with kaolin as the activator. CONCLUSION: The TEG assays evaluated were reproducible and present with an acceptable CV% for routine clinical practice. Kaolin and TF 1:17,000 equally affected the clot formation variables. Storage of WB for up to 30 minutes in citrate did not, except...

  7. Preparation and Ethanol Sensing Properties of ZnO Nanoparticles via a Novel Sol-Gel Method

    OpenAIRE

    Ahmadi Daryakenari, A.; AHMADI DARYAKENARI M.; Bahari, Y.; Omivar, H.

    2012-01-01

    ZnO nanoparticles were prepared using a novel sol-gel method. Chemical reactions were carried out between zinc acetate and methanol under ambient conditions using monoethanol amine (MEA) as surfactant and subsequent heating at 2 0 0 ∘ C . The powders were calcined, pressed into pellets, and presintered. The properties of the product were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectra. For gas sensing experiment, etha...

  8. Rootlike Morphology of ZnO:Al Thin Film Deposited on Amorphous Glass Substrate by Sol-Gel Method

    OpenAIRE

    Heri Sutanto; Sufwan Durri; Singgih Wibowo; Hady Hadiyanto; Eko Hidayanto

    2016-01-01

    Zinc oxide (ZnO) and aluminum doped zinc oxide (ZnO:Al) thin films have been deposited onto a glass substrate by sol-gel spray coating method at atmospheric pressure. X-ray diffractometer (XRD), scanning electron microscopy (SEM), and UV-Vis spectrophotometer have been used to characterize the films. XRD spectra indicated that all prepared thin films presented the wurtzite hexagonal structure. SEM images exhibited rootlike morphology on the surface of thin films and the shortest root diameter...

  9. Comparison of the Sol-gel Method with the Coprecipitation Technique for Preparation of Hexagonal Barium Ferrite

    Institute of Scientific and Technical Information of China (English)

    WANG Jing-ping; LIU Ying; ZHANG Mi-lin; QIAO Ying-jie; XIA Tian

    2008-01-01

    Hexagonal barium ferrite BaFe12O19 particles were prepared by sol-gel and coprecipitation methods,respectively.The composition of the so-obtained materials was investigated by means of XRD.By the sol-gel method,non-anticipated intermediate crystalline phases,such as γ-Fe2O3,α-Fe2O3,BaCO3,and BaFe2O4 etc.,were formed with the delay of the formation of BaFe12O19.The formation of single phase BaFe12O19 required calcination at 850 ℃ for 4 h.On the other hand,using copreeipitation technique,amorphous hydroxide precursor was directly transferred into BaFe12O19 almost without the formation of intermediate crystalline phases.BaFe12O19 was prepared by calcining at 700 ℃ for 3 h.The results were confirmed by ESEM and VSM analyses.Based on the already reported results and the observed results in this study,it can be concluded that the coprecipitaion technique is easier to control than the sol-gel method for preparation of BaFe12O19 at a low temperature.

  10. [Double-blind method of using solcoseryl ophthalmic gel and 2,4% cysteine in ophthalmic gel in patients with chronic recurrent keratitis and keratitis sicca].

    Science.gov (United States)

    Krzystkowa, K M; Hydzikowa, M; Szpytma, R

    1991-06-01

    A double blind study with Solcoseryl compounds in ophthalmic gel and with 2.4% cystein in ophthalmic gel was performed in the period 1985-1988; it was used in 18 cases: with chronic recurrent keratitis (11 patients) and sicca keratitis (7 patients). Observed was the influence of these compounds on the epithelialization of the cornea, on the improvement of corneal transparency, the diminutation of the troubles connected with dessication of the eye in sicca keratitis. In spite of the small number of cases the observations were interesting. In patients with a chronic recurrent keratitis the influence of both compounds showed to be beneficial for the condition of the cornea. In patients with keratitis sicca one could observe a better tolerance of the Solcoseryl ophthalmic gel which could be applied for a longer period in comparison with cystein in gel.

  11. Preparation of nanocrystalline Mg4Nb2O9 by citrate gel method

    Indian Academy of Sciences (India)

    A Vadivel Murugan; A B Gaikwad; V Ravi

    2006-02-01

    A gel was formed when a aqueous solution of Mg(NO3)2, NbF5 and citric acid in stoichiometric ratio was heated on a water bath. No precipitation was observed at acidic pH and gellation was complete with evaporation of the solvent. This gel on decomposition at 750°C produced nanocrystallites of ternary oxide, Mg4Nb2O9 (M4N2). The phase contents and lattice parameters were studied by powder X-ray diffraction (XRD) at various temperatures. Particle size and morphology were studied by transmission electron spectroscopy (TEM). For comparison, M4N2 powders were also prepared by conventional ceramic route at 900°C.

  12. Photocatalytic degradation for methylene blue using zinc oxide prepared by codeposition and sol-gel methods.

    Science.gov (United States)

    Shen, Wenzhong; Li, Zhijie; Wang, Hui; Liu, Yihong; Guo, Qingjie; Zhang, Yuanli

    2008-03-21

    Zinc oxide nanoparticle was obtained by zinc hydrate deposited on the silica nanoparticle surface and zinc hydrate was dispersed in starch gel. The structure of zinc oxide particle was characterized by nitrogen adsorption-desorption and XRD, the morphology was observed by TEM. The result showed that the zinc oxide nanoparticle deposited on the silica nanoparticle surface was well-dispersed and less than 50nm, displayed higher photocatalytic activity for methylene blue degradation. However, the zinc oxide nanoparticle in a size of 60nm was derived from starch gel and showed poorer photocatalytic activity. It provided a simple and effective route to prepare zinc oxide nanoparticle with higher photocatalytic activity through depositing zinc oxide on the silica particle surface, moreover, the catalyst is easier to recover due to its higher density.

  13. An immersed boundary method for two-phase fluids and gels and the swimming of Caenorhabditis elegans through viscoelastic fluids

    Science.gov (United States)

    Lee, Pilhwa; Wolgemuth, Charles W.

    2016-01-01

    The swimming of microorganisms typically involves the undulation or rotation of thin, filamentary objects in a fluid or other medium. Swimming in Newtonian fluids has been examined extensively, and only recently have investigations into microorganism swimming through non-Newtonian fluids and gels been explored. The equations that govern these more complex media are often nonlinear and require computational algorithms to study moderate to large amplitude motions of the swimmer. Here, we develop an immersed boundary method for handling fluid-structure interactions in a general two-phase medium, where one phase is a Newtonian fluid and the other phase is viscoelastic (e.g., a polymer melt or network). We use this algorithm to investigate the swimming of an undulating, filamentary swimmer in 2D (i.e., a sheet). A novel aspect of our method is that it allows one to specify how forces produced by the swimmer are distributed between the two phases of the fluid. The algorithm is validated by comparing theoretical predictions for small amplitude swimming in gels and viscoelastic fluids. We show how the swimming velocity depends on material parameters of the fluid and the interaction between the fluid and swimmer. In addition, we simulate the swimming of Caenorhabditis elegans in viscoelastic fluids and find good agreement between the swimming speeds and fluid flows in our simulations and previous experimental measurements. These results suggest that our methodology provides an accurate means for exploring the physics of swimming through non-Newtonian fluids and gels.

  14. PHASE STRUCTURE OF W-DOPED NANO-TiO2 PRODUCED BY SOL-GEL METHOD

    Institute of Scientific and Technical Information of China (English)

    Yucheng Wu; Xiaoye Hu; Ting Xie; Guanghai Li; Lide Zhang

    2005-01-01

    With Ti(OBu)4 as precursor, and HAc as complexing agent, pure and W-doped TiO2 gelatins were prepared by a sol-gel method. During the process of gel formation, metal ions were dispersed in the porous TiO2 matrix.Then, powders of nano-TiO2 and W-doped nano-TiO2 were prepared by drying, grinding and heat treatment at different temperatures. The grain size and structure of the samples, pure TiO2 and W-doped, and treated at different temperatures,were studied by X-ray diffraction (XRD), Beckman Coulter Sorption Analysis and TEM.Results showed that, with increasing temperature, the TiO2 transformed from anatase to rutile and the grain size increased. This transformation and grain growth of TiO2 could be retarded by doping with W.

  15. Synthesis of Li2FeSiO4/C composite by sol-gel citric acid assisted method

    Directory of Open Access Journals (Sweden)

    Milović Miloš D.

    2016-01-01

    Full Text Available This paper describes a procedure for the synthesis of the composite Li2FeSiO4/C by sol-gel method using citric acid as a chelating agent; the resulting gel precursor was thermally treated in a slightly reductive atmosphere of nitrogen with five percent of hydrogen, whereupon the in situ decomposition of citric acid to carbon occurs during formation of the Li2FeSiO4. The obtained nanocrystalline powder (with mean crystallite size of 27nm crystallized in the P21/n space group as confirmed by X-ray diffractometry. The morphology of the powder was examined by scanning electron microscopy which revealed a wide distribution of particles by size, from 100 to 500 nm. The material has been tested as cathode in lithium-ion cell and exhibits high efficiency and almost theoretical capacity.

  16. Efficient method of protein extraction from Theobroma cacao L. roots for two-dimensional gel electrophoresis and mass spectrometry analyses.

    Science.gov (United States)

    Bertolde, F Z; Almeida, A-A F; Silva, F A C; Oliveira, T M; Pirovani, C P

    2014-07-04

    Theobroma cacao is a woody and recalcitrant plant with a very high level of interfering compounds. Standard protocols for protein extraction were proposed for various types of samples, but the presence of interfering compounds in many samples prevented the isolation of proteins suitable for two-dimensional gel electrophoresis (2-DE). An efficient method to extract root proteins for 2-DE was established to overcome these problems. The main features of this protocol are: i) precipitation with trichloroacetic acid/acetone overnight to prepare the acetone dry powder (ADP), ii) several additional steps of sonication in the ADP preparation and extractions with dense sodium dodecyl sulfate and phenol, and iii) adding two stages of phenol extractions. Proteins were extracted from roots using this new protocol (Method B) and a protocol described in the literature for T. cacao leaves and meristems (Method A). Using these methods, we obtained a protein yield of about 0.7 and 2.5 mg per 1.0 g lyophilized root, and a total of 60 and 400 spots could be separated, respectively. Through Method B, it was possible to isolate high-quality protein and a high yield of roots from T. cacao for high-quality 2-DE gels. To demonstrate the quality of the extracted proteins from roots of T. cacao using Method B, several protein spots were cut from the 2-DE gels, analyzed by tandem mass spectrometry, and identified. Method B was further tested on Citrus roots, with a protein yield of about 2.7 mg per 1.0 g lyophilized root and 800 detected spots.

  17. A simple laser ablation ICPMS method for the determination of trace metals in a resin gel.

    Science.gov (United States)

    Gao, Yue; Lehto, Niklas

    2012-04-15

    Trace metal analysis of DGT gels using laser ablation inductively coupled plasma (LA-ICP-MS) has traditionally been carried out by ablating single spots along a line to provide high resolution data on trace metal distributions on a resin gel. This work compares the performance of two different LA-ICPMS systems, one at Lancaster University, UK and another at VUB, Belgium, in terms of instrument sensitivity and limit of detection in the analysis of trace metals (Co, Ni, Cu, Zn, Cd, and Pb) bound by a DGT resin gel using SPR-IDA resin. No defocusing of the laser beam was necessary to prevent burning through the resin gel and the internal standardization became very simple by using (13)C, naturally present in the resin-gel, instead of impregnating a back-up layer with (115)In. Furthermore, this work also explores the option of analysing the spatial distribution of resin bound trace metals by means of ablating a continuous line between two points and considers the advantages of using this approach. The work found that the LODs assessed on blank samples for Cu and Pb are similar for both LA-ICPMS systems, while for Co, Ni and Zn they are lower for the one at VUB and for Cd for the other one at Lancaster. The work found that the laser ablation systems at the two laboratories allowed more precise control over laser power and spot size than previously reported. For the line scan, the optimum scan parameters were determined as: scan speed of 50 μm s(-1), output energy of 40% and repetition rate of 30 Hz. An acquisition time of 25 ms, resulted in a much lower resolution (10 μm) compared to the spot ablation (a crater size of 100 μm and also some space between craters) and a better sensitivity. The LODs using the line scan were found to be lower than those obtained by the spot ablation. However, for some of the metals the difference is rather small. This work suggests that the time and gas consumption achieved by using the line scan is about 30% lower than for the

  18. Removal of Chronic Intravascular Blood Clots using Liquid Plasma

    Science.gov (United States)

    Jung, Jae-Chul; Choi, Myeong; Koo, Il; Yu, Zengqi; Collins, George

    2011-10-01

    An electrical embolectomy device for removing chronic intravascular blood clots using liquid plasma under saline environment was demonstrated. We employed a proxy experimental blood clot model of deep vein thrombosis (DVT) and actual equine blood clot. Thermal damage to contiguous tissue and the collagen denaturing via the plasma irradiation were investigated by histological analysis using birefringence of the tissue and verified by FT-IR spectroscopic study, respectively, which showed the high removal rate up to 2 mm per minute at room temperature and small thermal damage less than 200 μm.

  19. Fibrin clot structure and platelet aggregation in patients with aspirin treatment failure.

    Directory of Open Access Journals (Sweden)

    Søs Neergaard-Petersen

    Full Text Available BACKGROUND: Aspirin is a cornerstone in prevention of cardiovascular events and modulates both platelet aggregation and fibrin clot formation. Some patients experience cardiovascular events whilst on aspirin, often termed aspirin treatment failure (ATF. This study evaluated both platelet aggregation and fibrin clot structure in patients with ATF. METHODS: We included 177 stable coronary artery disease patients on aspirin monotherapy. Among these, 116 (66% had ATF defined as myocardial infarction (MI whilst on aspirin. Platelet aggregation was assessed by Multiplate® aggregometry and VerifyNow®, whereas turbidimetric assays and scanning electron microscopy were employed to study fibrin clot characteristics. RESULTS: Enhanced platelet aggregation was observed in patients with ATF compared with non-MI patients following stimulation with arachidonic acid 1.0 mM (median 161 (IQR 95; 222 vs. 97 (60; 1776 AU*min, p = 0.005 and collagen 1.0 µg/mL (293 (198; 427 vs. 220 (165; 370 AU*min, p = 0.03. Similarly, clot maximum absorbance, a measure of fibrin network density, was increased in patients with ATF (0.48 (0.41; 0.52 vs. 0.42 (0.38; 0.50, p = 0.02, and this was associated with thinner fibres (mean ± SD: 119.7±27.5 vs. 127.8±31.1 nm, p = 0.003 and prolonged lysis time (552 (498; 756 vs. 519 (468; 633 seconds; p = 0.02. Patients with ATF also had increased levels of C-reactive protein (CRP (1.34 (0.48; 2.94 and 0.88 (0.32; 1.77 mg/L, p = 0.01 compared with the non-MI group. Clot maximum absorbance correlated with platelet aggregation (r = 0.31-0.35, p-values<0.001 and CRP levels (r = 0.60, p<0.001. CONCLUSIONS: Patients with aspirin treatment failure showed increased platelet aggregation and altered clot structure with impaired fibrinolysis compared with stable CAD patients without previous MI. These findings suggest that an increased risk of aspirin treatment failure may be identified by measuring both platelet

  20. Utility of single-energy and dual-energy computed tomography in clot characterization: An in-vitro study.

    Science.gov (United States)

    Brinjikji, Waleed; Michalak, Gregory; Kadirvel, Ramanathan; Dai, Daying; Gilvarry, Michael; Duffy, Sharon; Kallmes, David F; McCollough, Cynthia; Leng, Shuai

    2017-06-01

    Background and purpose Because computed tomography (CT) is the most commonly used imaging modality for the evaluation of acute ischemic stroke patients, developing CT-based techniques for improving clot characterization could prove useful. The purpose of this in-vitro study was to determine which single-energy or dual-energy CT techniques provided optimum discrimination between red blood cell (RBC) and fibrin-rich clots. Materials and methods Seven clot types with varying fibrin and RBC densities were made (90% RBC, 99% RBC, 63% RBC, 36% RBC, 18% RBC and 0% RBC with high and low fibrin density) and their composition was verified histologically. Ten of each clot type were created and scanned with a second generation dual source scanner using three single (80 kV, 100 kV, 120 kV) and two dual-energy protocols (80/Sn 140 kV and 100/Sn 140 kV). A region of interest (ROI) was placed over each clot and mean attenuation was measured. Receiver operating characteristic curves were calculated at each energy level to determine the accuracy at differentiating RBC-rich clots from fibrin-rich clots. Results Clot attenuation increased with RBC content at all energy levels. Single-energy at 80 kV and 120 kV and dual-energy 80/Sn 140 kV protocols allowed for distinguishing between all clot types, with the exception of 36% RBC and 18% RBC. On receiver operating characteristic curve analysis, the 80/Sn 140 kV dual-energy protocol had the highest area under the curve for distinguishing between fibrin-rich and RBC-rich clots (area under the curve 0.99). Conclusions Dual-energy CT with 80/Sn 140 kV had the highest accuracy for differentiating RBC-rich and fibrin-rich in-vitro thrombi. Further studies are needed to study the utility of non-contrast dual-energy CT in thrombus characterization in acute ischemic stroke.

  1. A new validated method for the simultaneous determination of benzocaine, propylparaben and benzyl alcohol in a bioadhesive gel by HPLC.

    Science.gov (United States)

    Pérez-Lozano, P; García-Montoya, E; Orriols, A; Miñarro, M; Ticó, J R; Suñé-Negre, J M

    2005-10-04

    A new HPLC-RP method has been developed and validated for the simultaneous determination of benzocaine, two preservatives (propylparaben (nipasol) and benzyl alcohol) and degradation products of benzocaine in a semisolid pharmaceutical dosage form (benzocaine gel). The method uses a Nucleosil 120 C18 column and gradient elution. The mobile phase consisted of a mixture of methanol and glacial acetic acid (10%, v/v) at different proportion according to a time-schedule programme, pumped at a flow rate of 2.0 ml min(-1). The DAD detector was set at 258 nm. The validation study was carried out fulfilling the ICH guidelines in order to prove that the new analytical method, meets the reliability characteristics, and these characteristics showed the capacity of analytical method to keep, throughout the time, the fundamental criteria for validation: selectivity, linearity, precision, accuracy and sensitivity. The method was applied during the quality control of benzocaine gel in order to quantify the drug (benzocaine), preservatives and degraded products and proved to be suitable for rapid and reliable quality control method.

  2. Correlation of fibrinogen level and absorbance change in both PT and APTT clotting curves on BCSXP

    Institute of Scientific and Technical Information of China (English)

    Xiaojie Zhang; Bing Bai

    2008-01-01

    Objective: To investigate the correlation of fibrinogen level and absorbance change in both PT and APTT clotting curves on BCSXP Analyzer. Methods:A serial of standard fibrinogen and 250 patient plasma samples with different qualities(normal, hemolysis,icterus, and lipemia) were run on BCSXP for assays PT, APTT and Fibrinogen. The absorbance change(DeltaA) from baseline to plateau in clotting curve was retrieved and analyzed on its correlation with the Fibrinogen result. Influence of plasma quality and PT/APTT result on this correlation was also studied respectively. Results:Both PT-DeltaA and APTT-DeltaA showed good linear regression with fibrinogen level in the sample, with Re close to 0.90 in both standard and patient samples. Hemolysis(H), itcterus(1) and lipemia(L) of the sample with valid clotting curves were found to have no significant difference in this correlation from normal(N) sample(R2: 0.83H, 0.92I 0.81L and 0.79N in PT; 0.89H, 0.95I, 0.91L and 0.89N in APTT) in either PT or APTT curve. PT or APTT result also has little impact on this correlation(0.71 in range 7 ~ 10 sec, 0.56 in10 ~ 20 sec, and 0.70 in 20 sec~; R2 in APTT: 0.88 in 20~30 sec,0.92 in 30~40 sec, and 0.95 in 40 sec~). Conclusion:The absorbance change in either PT or APTT clotting curve correlates well with the fibrinogen level in plasma, which is independent of plasma quality PT or APTT results. The absorbance change can be used as an alternative way to roughly estimate fibrinogen level in either PT or APTT clotting curve when the result of clauss-based fibrinogen measurement is not available.

  3. Luminescent Eosin Y–SiO{sub 2} hybrid nano and microrods prepared by sol–gel template method

    Energy Technology Data Exchange (ETDEWEB)

    Secu, M., E-mail: msecu@infim.ro [National Institute for Materials Physics, P.O. Box MG-7, Bucharest–Magurele, 077125 (Romania); Secu, C.E.; Sima, M.; Negrea, R.F.; Bartha, C. [National Institute for Materials Physics, P.O. Box MG-7, Bucharest–Magurele, 077125 (Romania); Dinescu, M.; Damian, V. [National Institute for Laser, Plasma and Radiation, P.O. Box MG-36, Bucharest–Magurele 077125 (Romania)

    2013-11-15

    Sol–gel chemistry within the pores of a polycarbonate template membrane was used for the preparation of Eosin Y–SiO{sub 2} hybrid nano- and microrods, using tetraethylorthosilicate [TEOS, Si(OC{sub 2}H{sub 5}){sub 4}] as the precursor in the presence of trifluoroacetic acid (TFA) catalyst. The ethanolic solution of Eosin-Y was added to the silica sol to trap dye molecules inside the SiO{sub 2} gel network during the gelation. Structural and morphological characterization using scanning electron microscopy (SEM) and luminescence microscopy have shown the formation of rods with 200 nm and 1.2 μm diameter and about 30 μm length, exhibiting luminescence properties. Spectroscopic characterization has shown that the luminescence is due to Eosin-Y molecule in the xerogel porous network, surrounded by a solvation shell given mainly by the water. -- Highlights: • Sol–gel template method was used to prepare Eosin Y–SiO{sub 2} hybrid rods-type structures. • Morphological characterization has shown nano- and microrods with luminescent properties. • Luminescence is due to Eosin-Y molecule surrounded by a solvation shell given by water.

  4. Semiquantitative Proteomic Analysis of the Human Spliceosome via a Novel Two-Dimensional Gel Electrophoresis Method ▿ §

    Science.gov (United States)

    Agafonov, Dmitry E.; Deckert, Jochen; Wolf, Elmar; Odenwälder, Peter; Bessonov, Sergey; Will, Cindy L.; Urlaub, Henning; Lührmann, Reinhard

    2011-01-01

    More than 200 proteins associate with human spliceosomes, but little is known about their relative abundances in a given spliceosomal complex. Here we describe a novel two-dimensional (2D) electrophoresis method that allows separation of high-molecular-mass proteins without in-gel precipitation and thus without loss of protein. Using this system coupled with mass spectrometry, we identified 171 proteins altogether on 2D maps of stage-specific spliceosomal complexes. By staining with a fluorescent dye with a wide linear intensity range, we could quantitate and categorize proteins as present in high, moderate, or low abundance. Affinity-purified human B, Bact, and C complexes contained 69, 63, and 72 highly/moderately abundant proteins, respectively. The recruitment and release of spliceosomal proteins were followed based on their abundances in A, B, Bact, and C spliceosomal complexes. Staining with a phospho-specific dye revealed that approximately one-third of the proteins detected in human spliceosomal complexes by 2D gel analyses are phosphorylated. The 2D gel electrophoresis system described here allows for the first time an objective view of the relative abundances of proteins present in a particular spliceosomal complex and also sheds additional light on the spliceosome's compositional dynamics and the phosphorylation status of spliceosomal proteins at specific stages of splicing. PMID:21536652

  5. Adapting capillary gel electrophoresis as a sensitive, high-throughput method to accelerate characterization of nucleic acid metabolic enzymes

    Science.gov (United States)

    Greenough, Lucia; Schermerhorn, Kelly M.; Mazzola, Laurie; Bybee, Joanna; Rivizzigno, Danielle; Cantin, Elizabeth; Slatko, Barton E.; Gardner, Andrew F.

    2016-01-01

    Detailed biochemical characterization of nucleic acid enzymes is fundamental to understanding nucleic acid metabolism, genome replication and repair. We report the development of a rapid, high-throughput fluorescence capillary gel electrophoresis method as an alternative to traditional polyacrylamide gel electrophoresis to characterize nucleic acid metabolic enzymes. The principles of assay design described here can be applied to nearly any enzyme system that acts on a fluorescently labeled oligonucleotide substrate. Herein, we describe several assays using this core capillary gel electrophoresis methodology to accelerate study of nucleic acid enzymes. First, assays were designed to examine DNA polymerase activities including nucleotide incorporation kinetics, strand displacement synthesis and 3′-5′ exonuclease activity. Next, DNA repair activities of DNA ligase, flap endonuclease and RNase H2 were monitored. In addition, a multicolor assay that uses four different fluorescently labeled substrates in a single reaction was implemented to characterize GAN nuclease specificity. Finally, a dual-color fluorescence assay to monitor coupled enzyme reactions during Okazaki fragment maturation is described. These assays serve as a template to guide further technical development for enzyme characterization or nucleoside and non-nucleoside inhibitor screening in a high-throughput manner. PMID:26365239

  6. Structural hierarchy governs fibrin gel mechanics.

    Science.gov (United States)

    Piechocka, Izabela K; Bacabac, Rommel G; Potters, Max; Mackintosh, Fred C; Koenderink, Gijsje H

    2010-05-19

    Fibrin gels are responsible for the mechanical strength of blood clots, which are among the most resilient protein materials in nature. Here we investigate the physical origin of this mechanical behavior by performing rheology measurements on reconstituted fibrin gels. We find that increasing levels of shear strain induce a succession of distinct elastic responses that reflect stretching processes on different length scales. We present a theoretical model that explains these observations in terms of the unique hierarchical architecture of the fibers. The fibers are bundles of semiflexible protofibrils that are loosely connected by flexible linker chains. This architecture makes the fibers 100-fold more flexible to bending than anticipated based on their large diameter. Moreover, in contrast with other biopolymers, fibrin fibers intrinsically stiffen when stretched. The resulting hierarchy of elastic regimes explains the incredible resilience of fibrin clots against large deformations.

  7. New Photoluminescence Phenomena of Ge/SiO2 Glass Synthesized by Sol-gel Method

    Institute of Scientific and Technical Information of China (English)

    Yu Ying FENG; Xiao Tian GU; Jia Hong ZHOU; Jian Chun BAO; Gang LI; Tian Hong LU

    2004-01-01

    New Ge/SiO2 glasses have been synthesized by heating the GeO2/SiO2 dry gels under H2 gas at 700℃. The resulting fluorescence spectra show that this kind of Ge/SiO2 glasses emit strong photoluminescence at 392 nm (3.12 eV), medium strong photoluminescence at 600 nm (2.05 eV)and weak photoluminescence at 770 nm (1.60 eV) respectively. Possible photolnminescence mechanisms are also discussed based on the results of X-ray diffraction (XRD) and X-ray photoelectron spectra (XPS).

  8. E-Beam Synthesis of Optical Organic-Inorganic Waveguide Film, prepared by Sol-gel Processing Method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Eun; Chon, Jina; Cho, Byung Gun; Noh, Seung Ju; Kwon, Yong Ku [Inha Univ., Incheon (Korea, Republic of)

    2011-07-01

    Optical organic-inorganic waveguide materials were synthesized by non-hydrolytic sol-gel reaction. To synthesize an alkoxysilane precursor, 3-glycidoxypropyl trimethoxysilane was reacted with azo-type materials at elevated temperature. This precursor was then reacted with 4.4-diphenol to synthesize the organic-inorganic hybrids by sol-gel reaction. The reaction mixture was then heat-treated for thermal condensation and methanol as a byproduct was also eliminated. After product has added 2.2-dimethoxy-2-phenylacetophenone for using UV-curing, the thin film was prepared by spin coating or bulk dropwise methode on the ITO substrate. It was cured by UV-curing methode and their patterned morphology and electro-optical properties were precisely measured. Also, E-beam process was used another cuing methode. This process was more efficient curing method than UV-curing methode. Because E-beam was very short curing time and very strong irradiation power. The detail results will be given in the meeting.

  9. Advances in clotting factor treatment for congenital hemorrhagic disorders.

    Science.gov (United States)

    Tarantino, Michael D; Aledort, Louis M

    2004-06-01

    During the last 50 years, clotting factor replacement has evolved from the use of frozen plasma in the 1950s, through the serendipitous discovery of cryoprecipitate in the 1960s and the development of purified clotting factors in the 1970s and 1980s, to the era of recombinant clotting factors beginning in the 1990s. The dawn of the new millennium has seen the refinement of recombinant factor (rF) VIII with enhanced safety via the elimination of plasma-derived culture media or product stabilizers. During the last decade of the 20th century, a cure for hemophilia through gene therapy became a possibility. This was, in part, facilitated by availability of large (dogs) and small (mice) animal models for hemophilia A and B. Although this review will focus primarily on clotting factor replacement, the reader may refer to recent discourse on gene therapy for hemophilia.

  10. Drinking Peroxide as 'Natural' Cure Leads to Dangerous Blood Clots

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_163513.html Drinking Peroxide as 'Natural' Cure Leads to Dangerous Blood Clots ... 9, 2017 (HealthDay News) -- Ingesting high-concentration hydrogen peroxide as a "natural cure" or cleansing agent may ...

  11. Adenosine diphosphate-decorated chitosan nanoparticles shorten blood clotting times, influencing the structures and varying the mechanical properties of the clots.

    Science.gov (United States)

    Chung, Tze-Wen; Lin, Pei-Yi; Wang, Shoei-Shen; Chen, Yen-Fung

    2014-01-01

    Chitosan nanoparticles (NPs) decorated with adenosine diphosphate (ADP) (ANPs) or fibrinogen (FNPs) were used to fabricate hemostatic NPs that can shorten blood clotting time and prevent severe local hemorrhage. The structure and mechanical properties of the blood clot induced with ANP (clot/ANP) or FNP (clot/FNP) were also investigated. The NPs, ANPs, and FNPs, which had particle sizes of 245.1 ± 14.0, 251.0 ± 9.8, and 326.5 ± 14.5 nm and zeta potentials of 24.1 ± 0.5, 20.6 ± 1.9, and 15.3 ± 1.5 mV (n=4), respectively, were fabricated by ionic gelation and then decorated with ADP and fibrinogen. The zeta potentials and Fourier transform infrared (FTIR) spectroscopy of the NPs confirmed that their surfaces were successfully coated with ADP and fibrinogen. The scanning electron microscope (SEM) micrographs of the structure of the clot induced with "undecorated" chitosan NPs (clot/NP), clot/ANP, and clot/FNP (at 0.05 wt%) were different, after citrated bloods had been recalcified by a calcium chloride solution containing NPs, ANPs, or FNPs. This indicated that many NPs adhered on the membrane surfaces of red blood cells, that ANPs induced many platelet aggregates, and that FNPs were incorporated into the fibrin network in the clots. Measurements of the blood clotting times (Tc) of blood clot/NPs, clot/ANPs, and clot/FNPs, based on 90% of ultimate frequency shifts measured on a quartz crystal microbalance (QCM), were significantly (P<0.05) (n=4) shorter than that of a clot induced by a phosphate-buffered solution (PBS) (clot/PBS) (63.6% ± 3.1%, 48.3% ± 6.2%, and 63.2% ± 4.7%, respectively). The ΔF2 values in the spectra of frequency shifts associated with the propagation of fibrin networks in the clot/ANPs and clot/FNPs were significantly lower than those of clot/PBS. Interestingly, texture profile analysis of the compressional properties showed significantly lower hardness and compressibility in clot/NPs and clot/ANPs (P<0.05 or better) (n=4) compared with

  12. Effect of Gold Nanoparticles on Prostate Dose Distribution under Ir-192 Internal and 18 MV External Radiotherapy Procedures Using Gel Dosimetry and Monte Carlo Method

    Directory of Open Access Journals (Sweden)

    Khosravi H.

    2015-03-01

    Full Text Available Background: Gel polymers are considered as new dosimeters for determining radiotherapy dose distribution in three dimensions. Objective: The ability of a new formulation of MAGIC-f polymer gel was assessed by experimental measurement and Monte Carlo (MC method for studying the effect of gold nanoparticles (GNPs in prostate dose distributions under the internal Ir-192 and external 18MV radiotherapy practices. Method: A Plexiglas phantom was made representing human pelvis. The GNP shaving 15 nm in diameter and 0.1 mM concentration were synthesized using chemical reduction method. Then, a new formulation of MAGIC-f gel was synthesized. The fabricated gel was poured in the tubes located at the prostate (with and without the GNPs and bladder locations of the phantom. The phantom was irradiated to an Ir-192 source and 18 MV beam of a Varian linac separately based on common radiotherapy procedures used for prostate cancer. After 24 hours, the irradiated gels were read using a Siemens 1.5 Tesla MRI scanner. The absolute doses at the reference points and isodose curves resulted from the experimental measurement of the gels and MC simulations following the internal and external radiotherapy practices were compared. Results: The mean absorbed doses measured with the gel in the presence of the GNPs in prostate were 15% and 8 % higher than the corresponding values without the GNPs under the internal and external radiation therapies, respectively. MC simulations also indicated a dose increase of 14 % and 7 % due to presence of the GNPs, for the same experimental internal and external radiotherapy practices, respectively. Conclusion: There was a good agreement between the dose enhancement factors (DEFs estimated with MC simulations and experiment gel measurements due to the GNPs. The results indicated that the polymer gel dosimetry method as developed and used in this study, can be recommended as a reliable method for investigating the DEF of GNPs in internal

  13. Enhancement of the electrochemical performance in LiFePO4 cathode materials synthesized by using the sol-gel method

    Directory of Open Access Journals (Sweden)

    Kyong-Soo Hong

    2010-11-01

    Full Text Available LiFePO4 powders were synthesized by using the sol-gel and the solid-state reaction methods. The chemical states of Fe ions were studied by using XPS, and their electrochemical properties according to the oxidation states of Fe ions were compared. The average oxidation state of Fe ions in LiFePO4 powders synthesized by using the solid-state reaction method was found to be Fe3+, on the other hand, that of Fe ions synthesized by using the sol-gel method was found to be Fe2+. The obtained discharge capacities were 50 mAh/g and 120 mAh/g at a rate 0.1 C in LiFePO4 synthesized by using the solid-state reaction and sol-gel methods, respectively. Relatively a good cycling stability was observed in sol-gel prepared powder.

  14. Molecularly imprinted polymer for 2, 4-dichlorophenoxyacetic acid prepared by a sol-gel method

    Indian Academy of Sciences (India)

    Yanli Sun

    2014-07-01

    Based on a sol-gel procedure, a molecularly imprinted polymer (MIP) for 2, 4-dichlorophenoxyacetic acid (2, 4-D) was synthesized, using phenyltrimethoxysilane (PTMOS), aminopropyltriethoxysilane (APTES) as monomers and tetraethoxysilane (TEOS) as cross-linking agent. In addition to the amount of the template, some factors in the sol-gel process: TEOS/APTES/PTMOS molar ratio, H2O/Si molar ratio, CH3CH2OH/Si molar ratio, etc. were investigated in detail. Results show that the optimum conditions for the preparation of the MIPs were 20:1.5:1 (TEOS: APTES: PTMOS), ca. 4 (H2O/Si), ca. 4 (CH3CH2OH/Si), respectively. Effects of various parameters involved in the adsorption process of 2, 4-D on MIP such as incubation time, pH, etc. were also evaluated. It is found that the adsorption attained equilibrium within 3 h, the optimum pH for adsorption was about 7 and the adsorption obeyed Langmuir model. Test results also demonstrated that the present MIP for 2, 4-D had large adsorption capacity (the maximum adsorption concluded from Langmuir model reached 243.3 mg/g) and good selectivity.

  15. Synthesis and characterization of CdO nano particles by the sol-gel method

    Science.gov (United States)

    Vadgama, V. S.; Vyas, R. P.; Jogiya, B. V.; Joshi, M. J.

    2017-05-01

    Cadmium Oxide (CdO) is an inorganic compound and one of the main precursors to other cadmium compounds. It finds applications in cadmium plating, storage batteries, in transparent conducting film, etc. Here, an attempt is made to synthesize CdO nano particles by sol-gel technique. The gel was prepared using cadmium nitrate tetra hydrate (Cd(NO3)2.4H2O) and aqueous ammonium hydroxide (NH4OH) as a precursor. The synthesized powder is further characterized by techniques like Powder X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and Thermal gravimetric analysis (TGA). Powder XRD analysis suggested the nano-crystalline nature of the sample with the cubic crystal system. Nano scaled particles of spherical morphology with the size ranging from 50-100 nm are observed from TEM images. While, FT-IR study is used to confirm the presence of different functional groups. Thermo-gravimetric analysis suggests the highly thermally stable nature of the samples. The results are discussed.

  16. A New Validated HPLC Method for the Simultaneous Determination of 2-phenoxyethanol, Methylparaben, Ethylparaben and Propylparaben in a Pharmaceutical Gel

    Science.gov (United States)

    Shabir, G. A.

    2010-01-01

    A novel reversed-phase HPLC method has been developed and validated for the simultaneous determination of 2-phenoxyethanol, methylparaben, ethylparaben and propylparaben preservatives. The method uses a Lichrosorb C8 (150×4.6 mm, 5 µm) column and isocratic elution. The mobile phase consisted of a mixture of acetonitrile, tetrahydrofuran and water (21:13:66, v/v/v), pumped at a flow rate of 1 ml/min. The UV detection was set at 258 nm. The method was validated with respect to accuracy, precision (repeatability and intermediate precision), specificity, linearity and range. All the parameters examined met the current recommendations for bioanalytical method validation. The developed method was successfully applied to the determination of commercially available pharmaceutical gel products for these preservatives. The procedure describes here is simple, selective and reliable for routine quality control analysis and stability tests. PMID:21218050

  17. Changes in clot lysis levels of reteplase and streptokinase following continuous wave ultrasound exposure, at ultrasound intensities following attenuation from the skull bone

    Directory of Open Access Journals (Sweden)

    Roijer Anders

    2008-08-01

    Full Text Available Abstract Background Ultrasound (US has been used to enhance thrombolytic therapy in the treatment of stroke. Considerable attenuation of US intensity is however noted if US is applied over the temporal bone. The aim of this study was therefore to explore possible changes in the effect of thrombolytic drugs during low-intensity, high-frequency continuous-wave ultrasound (CW-US exposure. Methods Clots were made from fresh venous blood drawn from healthy volunteers. Each clot was made from 1.4 ml blood and left to coagulate for 1 hour in a plastic test-tube. The thrombolytic drugs used were, 3600 IU streptokinase (SK or 0.25 U reteplase (r-PA, which were mixed in 160 ml 0.9% NaCl solution. Continuous-wave US exposure was applied at a frequency of 1 MHz and intensities ranging from 0.0125 to 1.2 W/cm2. For each thrombolytic drug (n = 2, SK and r-PA and each intensity (n = 9 interventional clots (US-exposed, n = 6 were submerged in thrombolytic solution and exposed to CW-US while control clots (also submerged in thrombolytic solution, n = 6 were left unexposed to US. To evaluate the effect on clot lysis, the haemoglobin (Hb released from each clot was measured every 20 min for 1 hour (20, 40 and 60 min. The Hb content (mg released was estimated by spectrophotometry at 540 nm. The difference in effect on clot lysis was expressed as the difference in the amount of Hb released between pairs of US-exposed clots and control clots. Statistical analysis was performed using Wilcoxon's signed rank test. Results Continuous-wave ultrasound significantly decreased the effects of SK at intensities of 0.9 and 1.2 W/cm2 at all times (P 2 and at 1.2 W/cm2, following 40 min exposure at 0.3, 0.6, 0.9 and at 1.2 W/cm2, and following 60 min of exposure at 0.05 0.3, 0.6, 0.9 and at 1.2 W/cm2 (all P Conclusion Increasing intensities of CW-US exposure resulted in increased clot lysis of r-PA-treated blood clots, but decreased clot lysis of SK-treated clots.

  18. Quantum dot based on tin/titanium mixed oxide doped with europium synthesized by protein sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Paganini, Paula P.; Felinto, Maria Claudia F.C., E-mail: paulapaganini@usp.b, E-mail: mfelinto@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Brito, Hermi F., E-mail: hefbrito@iq.usp.b [Universidade de Sao Paulo (IQ/USP), Sao Paulo, SP (Brazil). Inst. de Quimica. Lab. de Elementos do Bloco f

    2011-07-01

    Special luminescence biomarkers have been developed to find more sensitive fluoroimmunoassay methods. A new generation of these biomarkers is the semiconductors nanocrystals, known as quantum dots, doped with lanthanides. The use of lanthanides ions as luminescent markers has many advantages, for example a security method, low cost, high specificity and also the luminescence can be promptly measured with high sensibility and accuracy. The protein sol-gel is a modification of conventional method, in which the coconut water replacing the alkoxides normally used. The advantage is that, the proteins present in coconut water bind chemically with metal salts forming a polymer chain. This work presents nanoparticles based on tin/titanium mixed oxide doped with 3% of europium synthesized by protein sol-gel method. The nanoparticles were burned at 300 deg C, 500 deg C, 800 deg C and 1100 deg C. The samples were analyzed and characterized by thermal analysis, X-ray powder diffraction (XRD), infrared spectroscopy (IR) and scanning electron microscopy (SEM). The synthesis was effective and the nanoparticles showed nanometric size and structural differences with the annealing. To be used in the fluoroimmunoassays tests, these particles need to be functionalized before be connect with biological molecules and after this process, these nanoparticles going to be submitted at gamma radiation for sterilization. (author)

  19. Weight reduction is associated with increased plasma fibrin clot lysis.

    Science.gov (United States)

    Brzezińska-Kolarz, Beata; Kolarz, Marek; Wałach, Angelika; Undas, Anetta

    2014-11-01

    Obesity is associated with an increased risk of vascular thrombotic events. We sought to investigate how obesity and weight loss affect plasma fibrin clot properties. A total of 29 obese patients were studied before and after 3-month low-fat diet. Plasma fibrin clot parameters, including fibrin clot permeation coefficient (Ks), the lag phase of the turbidity curve, clot lysis time (t 50%), maximum rate of increase in D-dimer levels, and maximum D-dimer concentrations, were determined. Low-fat diet resulted in the reduction of body weight (P < .0001), body mass index (P < .0001), fat mass (P < .0001), total cholesterol (P < .0001), low-density lipoprotein cholesterol (P = .0005), triglycerides (P = .008), and plasminogen activator inhibitor 1 (P = .02), but not in fibrinogen or C-reactive protein. The only change in fibrin clot variables was shorter t 50% (P = .02). Baseline t 50%, but not posttreatment, correlated with waist circumference (r = .44, p = .02). This study demonstrates that weight loss in obese people can increase the efficiency of fibrin clot lysis.

  20. Synthesis and characterization of transparent conductive zinc oxide thin films by sol-gel spin coating method

    Science.gov (United States)

    Winarski, David

    Zinc oxide has been given much attention recently as it is promising for various semiconductor device applications. ZnO has a direct band gap of 3.3 eV, high exciton binding energy of 60 meV and can exist in various bulk powder and thin film forms for different applications. ZnO is naturally n-type with various structural defects, which sparks further investigation into the material properties. Although there are many potential applications for this ZnO, an overall lack of understand and control of intrinsic defects has proven difficult to obtain consistent, repeatable results. This work studies both synthesis and characterization of zinc oxide in an effort to produce high quality transparent conductive oxides. The sol-gel spin coating method was used to obtain highly transparent ZnO thin films with high UV absorbance. This research develops a new more consistent method for synthesis of these thin films, providing insight for maintaining quality control for each step in the procedure. A sol-gel spin coating technique is optimized, yielding highly transparent polycrystalline ZnO thin films with tunable electrical properties. Annealing treatment in hydrogen and zinc atmospheres is researched in an effort to increase electrical conductivity and better understand intrinsic properties of the material. These treatment have shown significant effects on the properties of ZnO. Characterization of doped and undoped ZnO synthesized by the sol-gel spin coating method was carried out using scanning electron microscopy, UV-Visible range absorbance, X-ray diffraction, and the Hall Effect. Treatment in hydrogen shows an overall decrease in the number of crystal phases and visible absorbance while zinc seems to have the opposite effect. The Hall Effect has shown that both annealing environments increase the n-type conductivity, yielding a ZnO thin film with a carrier concentration as high as 3.001 x 1021 cm-3.

  1. Catalytic properties of Fe/SiO2-Al2O3 systems, obtained via sol-gel method

    Science.gov (United States)

    Kon'kova, T. V.; Gordienko, M. G.; Alekhina, M. B.; Men'shutina, N. V.

    2017-03-01

    The high efficacy of iron-containing catalysts based on SiO2-Al2O3 systems obtained via sol-gel method in the oxidative destruction of carmoisine azo dye in aqueous solutions is demonstrated. It is found that the stability of the catalysts with respect to the leaching of iron ions into a solution during catalysis grows along with the aluminum content in the composition of aluminosilicate supports. It is concluded that the synthesized catalysts are promising materials for purifying wastewaters contaminated with organic dyes.

  2. Preparation and characterization of ZnO and Fe-doped ZnO films by sol-gel method

    OpenAIRE

    Zhang, Xin; Wang,Jiangang; Ma, Jing; Hu, Jianwen

    2016-01-01

    ZnO and Fe-doped ZnO thin films are prepared on glass substrate by sol-gel method, and the surface morphology, structure and optical property are analyzed by scanning electron microscope (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and UV-Vis-NIR spectrophotometer. The results show that both films have a smooth surface and a hexagonal wurtzite structure with orienting along the (101) plane. Compared with the ZnO film, the surface of Fe-doped ZnO film becomes smoother, and its...

  3. Preparation and characterization of ZnO-TiO(2) films obtained by sol-gel method

    OpenAIRE

    Ivanova, T; Harizanova, A.; Koutzarova, T.; Vertruyen, Bénédicte

    2011-01-01

    The sol-gel route has been applied to obtain ZnO-TiO(2) thin films. For comparison, pure TiO(2) and ZnO films are also prepared from the corresponding solutions. The films are deposited by a spin-coated method on silicon and glass substrates. Their structural and vibrational properties have been studied as a function of the annealing temperatures (400-750 degrees C). Pure ZnO films crystallize in a wurtzite modification at a relatively low temperature of 400 degrees C, whereas the mixed oxide...

  4. Grain Size and Photocatalytic Activity of Nanometer TiO2 Thin Films Prepared by the Sol-gel Method

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Transparent anatase TiO2 nanometer thin films with photocatalytic activity were prepared via the sol-gel method on soda-lime glass. The thickness, crystalline phase, grain size, surface hydroxyl amount and so on were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-visible spectrophotometer (UV-VIS). The photocatalytic activity of TiO2 thin films was evaluated for the photocatalytic decolorization of aqueous methyl orange. The effects of film thickness on the crystalline phase, grain size, transmittance and photocatalytic activity of nanometer TiO2 thin films were discussed.

  5. Thermal properties of wool fabric treated by phosphorus-doped silica sols through sol-gel method

    Directory of Open Access Journals (Sweden)

    Zhang Wei

    2014-01-01

    Full Text Available Wool fabric was treated with silica sol and phosphorus doped silica sol by sol-gel method in order to improve its thermal properties and flame retardance. The thermal stability, combustion behavior, and smoke suppression of the control and finished wool fabric were analyzed using thermogravimetric analysis, limited oxygen index, micro combustion calorimeter, and smoke chamber. The results showed that wool fabric treated by phosphorus doped silica sol had excellent thermal properties and flame retardance with higher final char residue and LOI value. Furthermore, heat release rate and smoke density results indicated the safety performance of the treated wool fabric on fire.

  6. Preparation of Nd-doped gadolinium-gallium garnet laser ceramic powder by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    YAO Yan-ping; LIU Jing-he

    2006-01-01

    Preparation of Nd3+:Gd3Ga5O12 polycrystalline material by sol-gel method was preparated in this paper.The structure and the pattern of the sample were analyzed by thermogravimetric analysis and differential thermal analysis(TG-DTA),Infrared spectrum,XRD,TEM and electron spectrum,which indicated that the powder with good characteristics of 70-100 nm can be obtained by sintering at 1 000℃.It was shown that the chemical composition of the sample was agreed with experimental requirements by electron spectrum analysis.

  7. Preparation of nickel oxide thin films at different annealing temperature by sol-gel spin coating method

    Science.gov (United States)

    Abdullah, M. A. R.; Mamat, M. H.; Ismail, A. S.; Malek, M. F.; Alrokayan, Salman A. H.; Khan, Haseeb A.; Rusop, M.

    2016-07-01

    Preparation of NiO thin films at different annealing temperature by sol-gel method was conducted to synthesize the quality of the surface thin films. The effects of annealing temperature on the surface topology were systematically investigated. Our studies confirmed that the surface roughness of the thin films was increased whenever annealing temperature was increase. NiO thin films morphology structure analysis was confirmed by field emission scanning electron microscope. Surface roughness of the thin films was investigated by atomic force microscopy.

  8. Improvement of Mechanical, Thermal and Optical Properties of Barium Mixed Cobalt Tartrate Hydrate Crystals Grown by Gel Method

    OpenAIRE

    2015-01-01

    In this present work, CTH and BCTH crystals have been prepared by gel technique by using single diffusion method at room temperature. The as grown crystals were characterized by using XRD, FT-IR, UV, TG / DTA and Micro hardness studies. X-ray powder diffraction results analyzed by using suitable software suggest that a CTH and BCTH crystals belong to cubic crystal system. The unit cell volume is observed to increase with increase in the concentration of barium in cobalt tartrate due to the la...

  9. Effect of intermittent pneumatic compression on disability, living circumstances, quality of life, and hospital costs after stroke: secondary analyses from CLOTS 3, a randomised trial

    OpenAIRE

    2014-01-01

    Background\\ud \\ud The results of the CLOTS 3 trial showed that intermittent pneumatic compression (IPC) reduced the risk of deep vein thrombosis and improved survival in immobile patients with stroke. IPC is now being widely used in stroke units. Here we describe the disability, living circumstances, quality of life, and hospital costs of patients in CLOTS 3.\\ud \\ud Methods\\ud \\ud In CLOTS 3, a parallel group trial in 94 UK hospitals, immobile patients with stroke from days 0 to 3 of admissio...

  10. Simplified sample preparation method for protein identification by matrix-assisted laser desorption/ionization mass spectrometry: in-gel digestion on the probe surface

    DEFF Research Database (Denmark)

    Stensballe, A; Jensen, Ole Nørregaard

    2001-01-01

    Identification and detailed characterization of complex mixtures of proteins separated by polyacrylamide gel electrophoresis (PAGE) require optimized and robust methods for interfacing electrophoretic techniques to mass spectrometry. Peptide mapping by matrix-assisted laser desorption/ionization-......Identification and detailed characterization of complex mixtures of proteins separated by polyacrylamide gel electrophoresis (PAGE) require optimized and robust methods for interfacing electrophoretic techniques to mass spectrometry. Peptide mapping by matrix-assisted laser desorption...... for protein identification similar to that obtained by the traditional protocols for in-gel digestion and MALDI peptide mass mapping of human proteins, i.e. approximately 60%. The overall performance of the novel on-probe digestion method is comparable with that of the standard in-gel sample preparation...

  11. A colourimetric method for the determination of the degree of chemical cross-linking in aspartic acid-based polymer gels

    Directory of Open Access Journals (Sweden)

    B. Gyarmati

    2015-02-01

    Full Text Available A 2,4,6-trinitrobenzenesulphonic acid (TNBS-based assay is developed to determine the degree of chemical cross-linking in aspartic acid-based polymer gels. The conventional colourimetric method for the quantitative determination of amine groups is difficult to use in polymer networks; thus, an improved method is developed to analyse polymer gels swollen in dimethyl sulfoxide (DMSO. Reaction products of the derivatizing reaction are examined by NMR. The chemical stability of the reagent is increased in DMSO, and the method shows satisfactory linearity and accuracy. The degree of chemical cross-linking in the investigated gels is close to its theoretical maximum, but the conversion of the pendant amine groups to cross-linking points is strongly dependent on the feed composition of the gels.

  12. Room temperature ferromagnetism of Mn-doped SnO{sub 2} thin films fabricated by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Xiao Yuhua [Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000 (China)], E-mail: xiaoyh04@lzu.cn; Ge Shihui; Xi Li; Zuo Yalu; Zhou Xueyun; Zhang Bangmin; Zhang Li [Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000 (China); Li Chengxian; Han Xiufeng; Wen Zhenchao [State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100080 (China)

    2008-09-15

    Sn{sub 1-x}Mn{sub x}O{sub 2} (x {<=} 0.11) thin films spin-coated on Si (1 1 1) substrate were fabricated by sol-gel method. X-ray diffraction revealed that single-phase rutile polycrystalline structure was obtained for x up to about 0.078. Evolution of the lattice parameters and X-ray photoelectron spectroscopy studies confirmed the incorporation of Mn{sup 3+} cations into rutile SnO{sub 2} lattice. Magnetic measurements revealed that all Sn{sub 1-x}Mn{sub x}O{sub 2} thin films exhibit ferromagnetism at room temperature, which is identified as an intrinsic characteristic. Magnetization data showed that the average magnetic moment per Mn atom decreased and the coercivity increases with increasing Mn content. The origin of room temperature ferromagnetism can be understood in terms of the percolation of the bound magnetic polaron. Our experimental results prove that the sol-gel method is an effective method for fabrication of transition metal doped SnO{sub 2} nanostructures with room temperature ferromagnetism by chemical synthesis.

  13. WGA-based lectin affinity gel electrophoresis: A novel method for the detection of O-GlcNAc-modified proteins.

    Science.gov (United States)

    Kubota, Yuji; Fujioka, Ko; Takekawa, Mutsuhiro

    2017-01-01

    Post-translational modification with O-linked β-N-acetylglucosamine (O-GlcNAc) occurs selectively on serine and/or threonine residues of cytoplasmic and nuclear proteins, and dynamically regulates their molecular functions. Since conventional strategies to evaluate the O-GlcNAcylation level of a specific protein require time-consuming steps, the development of a rapid and easy method for the detection and quantification of an O-GlcNAcylated protein has been a challenging issue. Here, we describe a novel method in which O-GlcNAcylated and non-O-GlcNAcylated forms of proteins are separated by lectin affinity gel electrophoresis using wheat germ agglutinin (WGA), which primarily binds to N-acetylglucosamine residues. Electrophoresis of cell lysates through a gel containing copolymerized WGA selectively induced retardation of the mobility of O-GlcNAcylated proteins, thereby allowing the simultaneous visualization of both the O-GlcNAcylated and the unmodified forms of proteins. This method is therefore useful for the quantitative detection of O-GlcNAcylated proteins.

  14. Nd-doped barium titanate ceramics with various Ti/Ba ratios prepared by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    SHI Qizhen; CUI Bin; WANG Hui; TIAN Jing; CHANG Zhuguo; HOU Yudong

    2005-01-01

    The Nd-doped BaTiO3 nanocrystalline powders and ceramics with different Ti/Ba ratios were prepared by sol-gel method. Phases and microstructures of the Nd-doped BaTiO3based powders and ceramics were characterized by XRD, SEM and TEM methods. The results revealed that the powders synthesized by sol-gel method were nanometer scale (30-60 nm)and were mainly composed of cubic BaTiO3 with a small amount of BaCO3. After sintering at high temperature, both cubic BaTiO3 and BaCO3 were transformed into tetrahedron BaTiO3 phase.The dielectric properties of the ceramics were also determined and the influence of Ti/Ba ratio on the dielectric properties was discussed. The Tc did not change with the variation of Ti/Ba ratio,while the εmax increased firstly and then decreased. The excess TiO2 is benefit for the modification of ceramics' microstructure and dielectric properties.

  15. Humidity Sensing Elements Based on Zn-doped TiO2 Films Prepared via a Sol-gel Method

    Directory of Open Access Journals (Sweden)

    Zvezditza Nenova

    2015-06-01

    Full Text Available Humidity sensing elements have been prepared via a sol-gel method on the basis of titanium n-butoxide, doped with ZnO. By this method Zn-modified titania films have been deposited on alumina substrates with interdigitated silver palladium electrodes and subsequent sintering at temperatures of 400°С and 800°С. Scanning electron microscopy has been employed to determine the surface morphology of the films obtained. Structural and compositional characterization has been done by X-ray diffraction analysis and energy dispersive X-ray spectroscopy. Electrical measurements of the characteristics and parameters of the obtained samples have been taken by an impedance analyzer within a frequency range from 100Hz to 1MHz. The impact of the Zn-dopant and sintering temperature on the samples electrical properties has been studied. The samples obtained by the sol-gel method described can be used as humidity sensing elements which change their resistance given changes in relative humidity at frequencies of up to about 1kHz.DOI: http://dx.doi.org/10.5755/j01.ms.21.2.6244

  16. Study on UV Shielding TiO2 Thin Film Prepared by Sol-Gel Method

    Institute of Scientific and Technical Information of China (English)

    Shihai Zhao; Xiaohui Wang; Shaobo Xin; Qiang Jiang; Xiaoping Liang

    2006-01-01

    Titanium dioxide (TiO2) thin films were prepared on microscopes slides by sol-gel and dip-coating processes from specially formulated sols. The results show that there exists anatase and rutile structure of TiO2 when heat treatment temperature is 450℃, and at 800℃, TiO2 particle size is of below 100 nm and rutile structure is presented. In the range of 360 nm~400 nm the transmittance of TiO2 sol increases with the increasing of the concentration of Ti(OC4H9)4 in ethanol solution.The transmittance of TiO2 films with various number of the layer is measured to be 0% below 320 nm, and the three-layer TiO2 film is of the best UV resistance in the range of 320 nm~400 nm.

  17. Preparation of Ag-doped TiO2 Thin Film by Sol-gel Method

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Ag-TiO2 thin film has been prepared on glass substrate by sol-gel process. The structure and properties of the materials were studied by DTA, XRD, and EPR.The photocatalytic activity was examined by the photocatalytic degradation of dichlorophos. The analysis results indicate that the photocatalytic activity of the Ag-TiO2 thin film is higher than that of pure TiO2 thin film. It is also influenced by the content of anatase and heating temperature. The ESR result shows that the Ag-TiO2 thin film has more hydroxide radicals than pure TiO2 thin film after illuminated by UV light.

  18. C-ADU Gel Particle Preparation by Modified-External Gelation Method

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Kyung Cha; Eom, Sung Ho; Cho, Cho Moon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Carbon black powder as a carbon source in the final UCO kernel is added during the broth solution preparation, in the processing of UCO kernel fabrication. The preparation of a good quality UCO kernel is very difficult owing to the homogeneous distribution of carbon in a UCO kernel. The key technology used to obtain a good quality sphere (sphericity, density, C/U, O/U ratios) is a uniform distribution of carbon particles into the C-ADU gel sphere, i.e., during the gelation step of liquid droplets formation before the thermal treatment. We carried out carbon source selection experiments on the various kinds of carbon black powder and a dispersion test in a simulated broth solution. The CB10 sample shows that the relative cumulative velocity and the velocity distribution density have the highest value. This is a Cabot Emperor 1800 CB particle.

  19. Upconversion properties of Y2O3:Er films prepared by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    QIAO Yanmin; GUO Hai

    2009-01-01

    Y2O3:Er3+ films were prepared by a simple sol-gel process. The structural properties of Y2O3:Er3+ flints were characterized with X-ray diffraction, Fourier transform infrared spectroscopy and field emission scanning electron microscopy. The results indicated that the Y2O3:Er3+ f'rims might have high upconversion efficiency because of their low vibrational energy. Under 785 and 980 nm laser excitation, the samples showed green (2H11/2→4I15/2, 4S3/2→4I15/2) and red (4F9/2→4I15/2) upconversion emissions. The upconversion mechanisms were stud-led in detail through laser power dependence. Excited state absorption and energy transfer process were discussed as possible upconversion mechanisms. The cross relaxation process in Er3+ was also investigated.

  20. Photocatalytic Activity of Nanosized ZnWO4 Prepared by the Sol-gel Method

    Institute of Scientific and Technical Information of China (English)

    WU Yan; ZHANG Shi-cheng; ZHANG Li-wu; ZHU Yong-fa

    2007-01-01

    Nanosized ZnWO4 photocatalysts were successfully synthesized via the sol-gel process in a temperature range of 450-800 ℃. The grain size, crystal size, and crystallinity of ZnWO4 particles increased with the increase of calcination temperature and prolonging calcination time. The photocatalytic activity was measured for the degradation of an aqueous Rhodamine-B(RhB) solution and gaseous formaldehyde(FAD). With the increase of calcination temperature and time, the activities increased to a maximum and then decreased. ZnWO4 photocatalyst prepared at 550 ℃ for 10 h showed the highest activity, which is similar to the photocatalytic activity of P25TiO2 for the degradation of gaseous FAD. High crystallinity, large surface area, and good dispersion are responsible for the high photocatalytic performance of the prepared ZnWO4.

  1. Coating of LaCoO3 thin film with sol-gel dip coating method.

    Science.gov (United States)

    Okuyucu, Hasan; Dahl, Paul Inge; Einarsrud, Mari Ann

    2008-02-01

    LaCoO3 thin film was coated on Al2O3 single crystal by sol-gel route. Appropriate composition of precursors, chelating agents and the solvent put together into a flask and magnetically stirred on a magnetic stirrer. After having the red transparent solution, it was stirred for 12 hours before coating. Ultrasonically cleaned substrate is dipped into the solution and taken immediately into vertical furnace which is preheated at 550 degrees C. A dense amorphous film is coated on the substrate. Fired amorphous films are annealed at temperature between 900 degrees C and 1000 degrees C for 20 minutes in the air. Then coated film was characterized by means of XRD, AFM, and SEM. Conductivity of the film was measured to be -0.1819 for 881 degrees C for the log sigma value by assuming the thickness as

  2. Bismuth–titanium oxide nanopowders prepared by sol–gel method for photocatalytic applications

    Energy Technology Data Exchange (ETDEWEB)

    Solís-Casados, D.A. [Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM, Carretera Toluca-Atlacomulco Km 14.5, Unidad San Cayetano, Toluca 50200, Estado de México, México (Mexico); Escobar-Alarcón, L., E-mail: luis.escobar@inin.gob.mx [Departamento de Física, Instituto Nacional de Investigaciones Nucleares, Apdo. Postal 18-1027, México DF 11801, México (Mexico); Arrieta-Castañeda, A.; Haro-Poniatowski, E. [Departamento de Física, Universidad Autónoma Metropolitana Iztapalapa, Apdo. Postal 55-534, México DF, México (Mexico)

    2016-04-01

    TiO{sub 2} has been widely studied for photocatalytic applications; however, its band gap is so large (Eg = 3.2 eV for anatase) that it can only be excited by ultraviolet light which accounts for only 5% of the incoming solar energy. Thus, it is important to develop a visible light driven photocatalyst with a lower band gap value. For this purpose, different TiO{sub 2}–Bi{sub 2}O{sub 3} binary compounds were prepared by the sol–gel technique. The obtained materials were characterized by Energy Dispersed Spectroscopy, X Ray Diffraction, Transmission Electron Microscopy, Raman Spectroscopy and Diffuse Reflectance Spectroscopy, in order to obtain information on their chemical composition, crystalline structure, vibrational features and optical properties. Compositional characterization reveal that the Bi content can be varied from 0.3 to 43.6 at.% in an easy way in the binary compounds. Structural characterization shows that the starting material corresponds to the crystalline anatase phase of TiO{sub 2} and upon Bi addition a phase transition to bismuth titanates and finally to bismuth oxide occurs. Raman results suggest the formation of titanates for compounds with a low content of Bi whilst for higher metal contents a mixture of oxides is obtained. HRTEM results demonstrated that the prepared nanopowders are quite crystalline. Optical measurements reveal that the band gap narrows from 3.2 eV to values as low as 1.4 eV. The photocatalytic activity was tested in the degradation of Malachite Green dye under illumination using a solar simulator with good results. - Highlights: • Bismuth–Titanium oxide nanopowders were synthesized by the sol–gel technique. • The evolution of the different crystalline phases was determined. • Materials with band gap as low as 1.4 eV were obtained. • Good photocatalytic activity using visible light was observed.

  3. Do tutorials on application method enhance adapalene-benzoyl peroxide combination gel tolerability in the treatment of acne?

    Science.gov (United States)

    Kwon, Hyuck Hoon; Park, Seon Yong; Yoon, Ji Young; Min, Seonguk; Suh, Dae Hun

    2015-11-01

    Fixed-dose combination adapalene 0.1% and benzoyl peroxide 2.5% gel (A-BPO) has rarely been studied for Asian acne patients, while they have complained of local irritations more often when applying individual components. In this study, we compared A-BPO gel with benzoyl peroxide (BPO) in terms of efficacy and tolerability in Korean patients first, and assessed the clinical benefit of a dermatological tutorial on application technique in reducing irritations for A-BPO. This study was conducted as a single-blind controlled split-face trial for a 12-week period. Each half facial side of 85 patients was randomly assigned to either A-BPO or BPO. Success rate, lesion counts and safety profiles were evaluated (analysis I). During initial assignment, all patients were further randomized to either dermatological tutorial (DT) or non-tutorial (NT) subgroups depending on the presence of dermatologists' tutorials for application methods to their A-BPO sides. Clinical data of the A-BPO side was compared between two subgroups (analysis II). As a result, A-BPO gel outperformed BPO, demonstrating better efficacy in success rates and lesion counts as early as 1 week. However, A-BPO proved significantly less tolerable compared with both BPO and previous A-BPO data from Caucasians. Bioengineering measurements further confirmed clinical data (analysis I). The DT subgroup achieved much better tolerability with comparable therapeutic efficacies compared with the NT subgroup (analysis II). In conclusion, A-BPO demonstrated higher efficacies in acne compared with BPO in Korean patients, while skin irritation levels were notable concurrently. Dermatologists' education for application methods would significantly decrease these side-effects, maintaining superior efficacy levels.

  4. Studies on impact sensitivity of nanosized trinitrotoluene (TNT) confined in silica processed by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    S.V. INGALE; P.B. WAGH; P.U. SASTRY; C.B. BASAK; D. BANDYOPADHYAY; S.B. PHAPALE; Satish C. GUPTA

    2016-01-01

    Nano-sized trinitrotoluene (TNT) material restrained in silica gel has been prepared by using the sol-gel process to study the effect of varying porosity in gel on the sensitivity of TNT. The TNT content in the gel has been varied from 60 to 90 wt%(at fixed acetone/tetramethoxysilane ratio of 50). Also, for a fixed TNT content of 75 wt%, the pore structure in the gel has been varied by changing the ratio of silica gel precursor to the solvent. The resultant TNT–silica gel composites have been characterized using scanning electron microscopy, thermal analysis, small angle X-ray scattering and surface area analysis techniques. Impact sensitivity studies were carried out using Fall Hammer Impact Test. The results showed that the sensitivity of nanostructured explosives prepared by sol-gel process can be tailored precisely by controlling the process parameters.

  5. Thermal Stability and Luminescence Properties of Eu3+ and Tb3+ Complexes with a Silica Matrix by Sol-Gel Method

    Institute of Scientific and Technical Information of China (English)

    王淑萍; 王瑞芬; 张建军; 刘翠格

    2003-01-01

    Ternary complexes of europium and terbium with benzoic acid and 1, 10-phenanthroline [RE(BA)3phen] (BA=benzoate phen=1,10-phenanthroline) were introduced into a silica matrix by sol-gel method. The thermal stability and luminescence behavior of the complexes in silica gels were studied in comparison with the corresponding solid-state complexes by thermal decomposition, excitation and emission spectra. The thermal stability of the complexes is enhanced in silica gel matrix and the luminescence remaines unchanged.

  6. Suction Curettage for Removal of Retained Intrathoracic Blood Clots and Pleural Lesions

    OpenAIRE

    Redan, Jay Alan; Palmer, Meade Todd; Tylutki, Francis John

    1999-01-01

    Objective: To develop a thoracoscopic technique for correcting and/or removing an intrathoracic disease process using our existing operating room equipment and without a “small thoracotomy.” Methods and Procedures: Fifty-eight patients from October 1994 to April 1998 were prospectively studied. All were undergoing procedures involving the removal of a suspected benign (or infectious) pleural process or a retained blood clot. Three or four thoracic ports were used in all cases. Straight and cu...

  7. ZnO-SiO{sub 2} based nanocomposites prepared by a modified sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Grigorie, Alexandra Carmen [Politehnica University Timisoara, Faculty of Industrial Chemistry and Environmental Engineering, 6 V. Parvan Blv., RO-300223, Timisoara (Romania); Muntean, Cornelia, E-mail: cornelia.muntean@upt.ro [Politehnica University Timisoara, Faculty of Industrial Chemistry and Environmental Engineering, 6 V. Parvan Blv., RO-300223, Timisoara (Romania); Politehnica University Timisoara, Research Institute for Renewable Energy, 2 Piata Victoriei, RO-300006, Timisoara (Romania); Vlase, Titus [West University of Timisoara, 4 V. Parvan Blv., RO-300223, Timisoara (Romania); Locovei, Cosmin [Politehnica University Timisoara, Research Institute for Renewable Energy, 2 Piata Victoriei, RO-300006, Timisoara (Romania); Politehnica University Timisoara, Faculty of Mechanical Engineering, 1 Mihai Viteazul Blv., RO-300222, Timisoara (Romania); Stefanescu, Mircea [Politehnica University Timisoara, Faculty of Industrial Chemistry and Environmental Engineering, 6 V. Parvan Blv., RO-300223, Timisoara (Romania)

    2017-01-15

    This paper presents a study on nanocomposites formation in ZnO-SiO{sub 2} systems with different ZnO:SiO{sub 2} molar ratios (1:4, 1:1, and 4:1), prepared employing a sol-gel method modified by an original procedure. The evolution of ZnO-SiO{sub 2} systems depending on the composition and temperature was studied by thermal analysis, Fourier transform infrared spectroscopy, X-ray diffractometry and transmission electron microscopy. Zn(II) carboxylate was synthesized in situ in hybrid silica gels by redox reaction between zinc nitrate and 1,3-propanediol. Its thermal decomposition at low temperatures led to ZnO dispersed in the pores of silica matrix. Only for the 4:1 system, at 400 and 600 °C, ZnO nanocrystallites (average size ∼9 nm) embedded in the amorphous silica matrix were obtained, the other systems being amorphous. Whatever the mixture composition is, above 600 °C, ZnO reacts with SiO{sub 2} to form zinc silicate. At 800 °C, for both 1:4 and 1:1 systems, poor crystallized β-Zn{sub 2}SiO{sub 4} and α-Zn{sub 2}SiO{sub 4} phases embedded in silica matrix were formed. Increasing the temperature, at 1000 °C, only for 1:1 system, β-Zn{sub 2}SiO{sub 4} phase turned into single phase α-Zn{sub 2}SiO{sub 4} (average crystallites size 28.3 nm). For 4:1 composition, at 800 and 1000 °C, systems consisting of ZnO and α-Zn{sub 2}SiO{sub 4} nanocrystallites dispersed in silica were obtained. - Highlights: • By modified sol-gel method, ZnO/SiO{sub 2} and Zn{sub 2}SiO{sub 4}/SiO{sub 2} nanocomposites were obtained. • ZnO dispersed in silica matrix results from zinc carboxylate thermal decomposition. • Zinc carboxylate was synthesized in situ in hybrid silica gels via redox reaction. • Evolution of ZnO in SiO{sub 2} matrix depends on temperature and system composition.

  8. The Influence of Thermal Conditions on V2O5 Nanostructures Prepared by Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    M. Prześniak-Welenc

    2015-01-01

    Full Text Available This work presents the result of structure investigations of V2O5 nanorods grown from thin films and powders prepared by sol-gel method. To examine the best temperature of nanorods crystallization, thin films deposited by spin-coating method on quartz glass or silicon substrates and bulk xerogel powders were annealed at various temperatures ranging from 100°C to 600°C. The structure of the samples was characterized by X-ray diffraction method (XRD, scanning electron microscope (SEM, differential scanning calorimetry (DSC, thermogravimetric analysis (TGA, and mass spectroscopy (MS. The rod-like structure of V2O5 was obtained at 600°C on both quartz glass and silicon substrates and also from the bulk xerogel. The growth process and the effect of annealing treatment on the nanostructure are briefly discussed.

  9. Magnetic Properties of NiCuZn Ferrite Thin Films Prepared by the Sol-gel Method

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Ni0.4Cu0.2Zn0.4Fe2O4 thin films were fabricated on Si substrates by using the sol-gel method and rapid thermal annealing (RTA), and their magnetic properties and crystalline structures were investigated.The samples calcined at and above 600 ℃ have a single-phase spinel structure and the average grain size of the sample calcined at 600 ℃ is about 20 nm. The initial permeability μi, saturation magnetization Ms and coercivity Hc of the samples increase with the increasing calcination temperature. The sample calcined at 600 ℃ exhibits an excellent soft magnetic performance, which has μi=33.97 (10 MHz),Hc=15.62 Oe and Ms=228.877 emu/cm3. Low-temperature annealing can enhance the magnetic properties of the samples. The work shows that using the sol-gel method in conjunction with RTA is a promising way to fabricate integrated thin-film devices.

  10. Electrical stability of Al-doped ZnO transparent electrode prepared by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Tabassum, Samia, E-mail: shawon14@gmail.com; Yamasue, Eiji; Okumura, Hideyuki; Ishihara, Keiichi N.

    2016-07-30

    Highlights: • Al-doped ZnO thin film was deposited by sol-gel method in different annealing temperature and duration. • We examined the environmental stability in ambient and damp heat condition. • We investigated chemical state of thin film. • Better stability was observed in the film annealed at high temperature (600 °C) along with longer duration (120 min). • An ultrathin aluminum oxide layer formation was predicted by XPS measurement which protects further oxidation and improves stability. - Abstract: Al-doped zinc oxide (AZO) thin films have been considered as a promising alternative to tin doped indium oxide (ITO), which is currently used in various optoelectronic applications. However, the environmental stability of AZO film is not satisfactory, in that the resistivity is significantly increases in air. Here, we investigate the resistivity stability of AZO thin films prepared by sol-gel method using various annealing temperatures and durations. The degradation of resistivity property was observed for AZO films stored in ambient or damp heat environment, where the degradation rate was influenced by annealing temperature. A significant improvement of electrical stability was attained in AZO films that were prepared at high annealing temperature. The films, which showed the highest and the lowest increasing rate of resistivity, were further characterized in detail to shed light on the possible mechanisms explaining the improved stability through crystallinity, surface morphology and elemental state of the thin film.

  11. Fabrication of regular TiO2 nanoporous films derived by combining nanoimprint technique with sol-gel method.

    Science.gov (United States)

    Zhong, Peng; Que, Wenxiu; Zhang, Jin

    2010-11-01

    In this paper, honeycomb-like regular TiO2 nanoporous films deposited on different substrates including ITO glass and silicon wafer are fabricated by combining a nanoimprint technique with a sol-gel method. A novel soft polymer mold containing a thin layer of polymethylmethacrylate and a thicker layer of polydimethylsiloxane, which is obtained from an anodic aluminum oxide template, is carried out for the nanoimprint process. TiO2 precursor solution prepared by the sol-gel processing is used as the nanoimprinted material. After imprinting, the polydimethylsiloxane back layer is easily peeled off before the polymethylmethacrylate mold is chemically removed to avoid any demolding problem. The SEM images show that the honeycomb-like regular nanostructure of the initial anodic aluminum oxide template can be preserved completely on TiO2 via this method, and the XRD results indicate that there is a crystalline transition from amorphous to anatase of TiO2 after 450 degrees C heat treatment.

  12. Pore surface fractal analysis of PEG and La(III-doped mesoporous alumina obtained by the sol–gel method

    Directory of Open Access Journals (Sweden)

    TATJANA B. NOVAKOVIĆ

    2010-06-01

    Full Text Available Active porous alumina was prepared via a sol–gel method and subjected to thermal treatment in the temperature range 500–1200 °C. The addition of lanthanum effectively inhibited the surface area loss of the aluminas. Fractal analysis from nitrogen adsorption isotherm was used to study the pore surface roughness of alumina samples with different chemical compositions (PEG, PEG and lanthanum and calcinations conditions in terms of the surface fractal dimension, d. The Mahnke and Mögel (MM model was used to determine the value of d of La(III-doped alumina. Following the MM model, the d value of the activated aluminas increased as the calcination temperature increased from 500 to 700 °C but decreased after calcination at 1000, 1100 and 1200 °C. The addition of polyethylene glycol (PEG 5600 to the boehmite sol reduced the surface fractal of the activated alumina due to the heterogeneous distribution of the pores. With increasing La(III concentration from 0.015 to 0.045 mol La(III/ /mol Al(III, the d value of La-modified alumina samples decreased, indicating a smoother surface. The obtained PEG+La-doped boehmite sol can be used as a precursor dispersion for the deposition of mesoporous alumina coatings on stainless steel foil, by the spray pyrolysis method.

  13. Synthesis and Characterization of Anatase Titanium Dioxide Nanoparticles Using Egg White Solution via Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    Samira Bagheri

    2013-01-01

    Full Text Available Anatase titanium dioxide nanoparticles (TNPs are synthesized by a simple and cost-effective process with and without freshly water-soluble egg white proteins (albumin via sol-gel method. The main advantage of using egg white proteins as a gelling agent is that it can provide long-term stability for nanoparticles by preventing particles agglomeration. The X-ray diffraction and FTIR results indicate that the synthesized nanoparticles have only the anatase structure without the presence of any other phase impurities. Additionally, the TNPs are characterized by a number of techniques such as thermogravimetric analysis (TGA, X-ray diffraction analysis (XRD, transmission electron microscopy (TEM, Fourier transform infrared spectroscopy (FTIR, and ultraviolet visible spectra (UV-vis. The sizes of titanium dioxide nanoparticles with and without using egg white solution are 12.55±3.42 nm and 21.45±4.21 nm, respectively. The results indicate that egg white solution is a reliable and cheap green gelling agent that can be used as a matrix in the sol-gel method to synthesis tiny size TNPs.

  14. Preparation of Raspberry-like Superhydrophobic SiO2 Particles by Sol-gel Method and Its Potential Applications

    Directory of Open Access Journals (Sweden)

    Xu Gui-Long

    2011-12-01

    Full Text Available Raspberry‐like SiO2 particles with a nano‐micro‐binary structure were prepared by a simple sol‐gel method using tetraethoxysilane (TEOS and methyltriethoxysilane (MTES as precursors. The chemical components and morphology of the SiO2 particles were characterized by Fourier transform infrared spectroscopy (FT‐IR and a Transmission electron microscope (TEM. The surface topography and wetting behaviour of the raspberry‐like SiO2 surface were observed with a Scanning electron microscope (SEM and studied by the water/oil contact angle (CA, respectively. The thermal stability of the prepared SiO2 particles was characterized by TGA analysis. The results show that the highly dispersed SiO2 particles initially prepared by the sol‐gel method turn into raspberry‐like particles with during the aging process. The raspberry‐like SiO2 particles show superhydrophobicity and superoleophilicity across a wide range of pH values. The SiO2 particles were thermally stable up to 475°C, while above this temperature the hydrophobicity decreases and finally becomes superhydrophobic when the temperature reaches 600°C. The raspberry‐like SiO2 particles which were prepared have potential applications in the fields of superhydrophobic surfaces, water‐oil separation, anti‐corrosion and fluid transportation.

  15. An immersed boundary method for two-phase fluids and gels and the swimming of Caenorhabditis elegans through viscoelastic fluids

    Science.gov (United States)

    Lee, Pilhwa; Wolgemuth, Charles

    2016-11-01

    While swimming in Newtonian fluids has been examined extensively, only recently have investigations into microorganism swimming through non-Newtonian fluids and gels been explored. The equations that govern these more complex media are often nonlinear and require computational algorithms to study moderate to large amplitude motions of the swimmer. Here we develop an immersed boundary method for handling fluid-structure interactions in a general two-phase medium, where one phase is a Newtonian fluid and the other phase is viscoelastic. We use this algorithm to investigate the swimming of an undulating, filamentary swimmer in 2D. A novel aspect of our method is that it allows one to specify how forces produced by the swimmer are distributed between the two phases of the fluid. The algorithm is validated by comparison to theoretical predictions for small amplitude swimming in gels and viscoelastic fluids. We show how the swimming velocity depends on material parameters of the fluid and the interaction between the fluid and swimmer. In addition, we simulate the swimming of Caenorhabditis elegans in viscoelastic fluids and find good agreement between the swimming speeds and fluid flows in our simulations and previous experimental measurements. NIH R01 GM072004, NIH P50GM094503.

  16. Preparation of YAG: Ce3+ phosphor by sol-gel low temperature combustion method and its luminescent properties

    Institute of Scientific and Technical Information of China (English)

    YAN Xing-huang; ZHENG Song-sheng; YU Rui-min; CAI Jing; XU Zhi-wei; LIU Chun-jia; LUO Xue-tao

    2008-01-01

    YAG:Ce3+ phosphor was prepared by sol-gel low-temperature combustion method.The effects of the precursor properties and calcining temperature on the crystallization process,microscopic morphology and luminescent properties of phosphor were studied.The results indicate that the pure phase of YAG can be obtained at 800℃ by sol-gel low temperature combustion method,using citric acid as complexing agent.When the molar ratio of metal ion to citric acid is 2.0 and pH value is 2,the crystallinity increases and the phosphor particle size grows up gradually with the increase of the calcining temperature.The powders were characterized through thermal analysis,X-ray diffraction analysis and scanning electron microscope analysis.The excitation spectra of YAG: Ce3+ phosphor take on a double peak structure,and the peak value of the main excitation spectra occurs at 460nm and that of the emission spectra is near 530nm.With the gradual increase of the calcining temperature,the peak position of excitation and emission spectra remains basically unchanged,but its relative intensity increases gradually.

  17. Nanostructured Mesoporous Titanium Dioxide Thin Film Prepared by Sol-Gel Method for Dye-Sensitized Solar Cell

    Directory of Open Access Journals (Sweden)

    Yu-Chang Liu

    2011-01-01

    Full Text Available Titanium dioxide (TiO2 paste was prepared by sol-gel and hydrothermal method with various precursors. Nanostructured mesoporous TiO2 thin-film back electrode was fabricated from the nanoparticle colloidal paste, and its performance was compared with that made of commercial P25 TiO2. The best performance was demonstrated by the DSSC having a 16 μm-thick TTIP-TiO2 back electrode, which gave a solar energy conversion efficiency of 6.03%. The ability of stong adhesion on ITO conducting glass substrate and the high surface area are considered important characteristics of TiO2 thin film. The results show that a thin film with good adhesion can be made from the prepared colloidal paste as a result of alleviating the possibility of electron transfer loss. One can control the colloidal particle size from sol-gel method. Therefore, by optimizing the preparation conditions, TiO2 paste with nanoparticle and narrow diameter distribution was obtained.

  18. Optimization of the agar-gel method for isolation of migrating Ascaris suum larvae from the liver and lungs of pigs

    DEFF Research Database (Denmark)

    Saeed, I.; Roepstorff, A.; Rasmussen, T.;

    2001-01-01

    Experiments on use of an agar-gel method for recovery of migrating Ascaris suum larvae from the liver and lungs of pigs were conducted to obtain fast standardized methods. Subsamples of blended tissues of pig liver and lungs were mixed with agar to a final concentration of 1% agar and the larvae...... allowed to migrate out of the agar-gel into 0.9% NaCl at 38 degreesC. The results showed that within 3 h more than 88% of the recoverable larvae migrated out of the liver agar-gel and more than 83% of the obtained larvae migrated out of the lung agar-gel. The larvae were subsequently available in a very...

  19. Production of HfO2 thin films using different methods: chemical bath deposition, SILAR and sol-gel process

    Science.gov (United States)

    Kariper, İ. A.

    2014-08-01

    Hafnium oxide thin films (HOTFs) were successfully deposited onto amorphous glasses using chemical bath deposition, successive ionic layer absorption and reaction (SILAR), and sol-gel methods. The same reactive precursors were used for all of the methods, and all of the films were annealed at 300°C in an oven (ambient conditions). After this step, the optical and structural properties of the films produced by using the three different methods were compared. The structures of the films were analyzed by X-ray diffraction (XRD). The optical properties are investigated using the ultraviolet-visible (UV-VIS) spectroscopic technique. The film thickness was measured via atomic force microscopy (AFM) in the tapping mode. The surface properties and elemental ratios of the films were investigated and measured by scanning electron microscopy and energy-dispersive X-ray spectroscopy (EDX). The lowest transmittance and the highest reflectance values were observed for the films produced using the SILAR method. In addition, the most intense characteristic XRD peak was observed in the diffraction pattern of the film produced using the SILAR method, and the greatest thickness and average grain size were calculated for the film produced using the SILAR method. The films produced using SILAR method contained fewer cracks than those produced using the other methods. In conclusion, the SILAR method was observed to be the best method for the production of HOTFs.

  20. Phase formation and electrical properties of the LaCoO3 obtained by water-based sol-gel method with citric acid

    Directory of Open Access Journals (Sweden)

    Luminita Predoana

    2009-06-01

    Full Text Available In the present work the LaCoO3 formation from gel precursors obtained by water-based sol-gel method with citric acid was studied. As precursors La and Co nitrates were used. The obtained gels were analyzed by TG/DTA and TG/EGA. The decomposition of the gels takes place in two main steps with the evolution of the same volatile compounds (H2O, CO2 and NO2 leading to the conclusion that two types of bonding of the components in the gels occurred. The decomposition of the gels takes place up to 400°C. The gels thermally treated at 600°C lead to single pure perovskite rhombohedral phase of lanthanum cobalt oxide (LaCoO3. Some electrical properties of LaCoO3 measured in “operando” conditions, i.e. in gas fl ow, at atmospheric pressure (by using the differential step technique DST are presented and discussed.

  1. In vitro characterization of polyvinyl alcohol assisted hydroxyapatite derived by sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Kaygili, Omer, E-mail: okaygili@firat.edu.tr [Department of Physics, Faculty of Science, Firat University, 23119 Elazig (Turkey); Keser, Serhat [Department of Chemistry, Faculty of Science, Firat University, 23119 Elazig (Turkey); Al Orainy, R.H. [Physics Department, Sciences of Faculty for Girls, King Abdulaziz University, Jeddah (Saudi Arabia); Ates, Tankut [Department of Physics, Faculty of Science, Firat University, 23119 Elazig (Turkey); Yakuphanoglu, Fahrettin [Department of Physics, Faculty of Science, Firat University, 23119 Elazig (Turkey); Physics Department, Sciences of Faculty for Girls, King Abdulaziz University, Jeddah (Saudi Arabia)

    2014-02-01

    The synthesis and characterization of sol–gel derived hydroxyapatite (HAp) were investigated with the effects of the addition of polyvinyl alcohol (PVA) to the structural and material in vitro behavior. All samples were soaked in simulated body fluid (SBF) for 14 and 28 days. The characterization of bioceramics before and after immersing in SBF was carried out by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, differential thermal analysis (DTA), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) techniques. After the simulated body fluid period, the crystal structure and phase of HAp samples did not change significantly. The characteristic bands of hydroxyl, phosphate and carbonate groups were detected. HAp exhibited a thermal stability of room temperature to 1000 °C. The surface morphologies of the samples show an evident change with the soaking period in SBF. - Highlights: • The soaking period in SBF affects the surface morphology. • The Ca/P molar ratios change with the immersion time. • The as-prepared samples thermally stable from ∼ 25 to 1000 °C.

  2. Topical gel formulation and stability assessment of platelet lysate based on turbidimetric method

    Directory of Open Access Journals (Sweden)

    Soliman Mohammadi Samani

    2015-06-01

    Full Text Available Platelet-rich growth factors have attracted attentions of scientists and clinical practitioners who are involved in wound healing and regenerative medicine extensively, according to their unprecedented potential of promoting and catalyzing healing process. Platelet-rich growth factors are cost-benefit, available and more stable than recombinant human growth factors. These appealing characteristics have converted PRGF to one of the popular candidates for treatment of variety of wounds. According to these valuable properties, we decided to formulate and assess the effect of different excipients on the stability of such valuable protein based formulations. Different excipients have been chosen according to their effective ness on the stability of proteins and their application in other similar formulations. The stabilizing effect of excipients was evaluated by measuring heat-induced aggregation of growth factors by turbidimetric assay. Glycerol, glycine and dextrose were chosen as stabilizing excipients for these formulations. The results show that dextrose has more stabilizing effect on prevention of heat induced aggregation of the platelet lysate growth factors than glycerol and glycine. All of the formulations also contained antioxidant, chelating agents, preservative and carbopol934 in order to form appropriate gel.

  3. Characterization of Copper Oxide Nanoparticles Fabricated by the Sol-Gel Method

    Science.gov (United States)

    Kayani, Zohra Nazir; Umer, Maryam; Riaz, Saira; Naseem, Shahzad

    2015-10-01

    Copper oxide nanoparticles were successfully prepared by a sol-gel technique. An aqueous solution of copper nitrate Cu(NO3)2 and acetic acid was used as precursor. On addition of sodium hydroxide (NaOH) a precipitate of copper oxide was immediately formed. The copper oxide nanoparticles were characterized by use of x-ray diffractometry (XRD), thermogravimetric analysis (TGA), differential thermal analysis, differential scanning calorimetry, Fourier-transform infrared spectroscopy (FTIR), vibrating sample magnetometry, and scanning electron microscopy (SEM). The XRD pattern contained sharp peaks of copper oxide nanoparticles with mixed cuprite and tenorite phases. Use of the Debye-Scherer equation showed that the crystallite size of the copper oxide nanoparticles increased with increasing annealing temperature. FTIR spectra revealed vibration of the CuO band at 473 cm-1; a band at 624 cm-1 was attributed to Cu2O. Maximum coercivity and saturation magnetization of the nanoparticles were 276 Oe and 0.034 emu/g, respectively. SEM micrographs of the nanoparticles revealed the presence of spherical nanoparticles of the tenorite phase whereas the cuprite phase was in the form of a compact deposit.

  4. TiO2 Thin Film via Sol-Gel Method: Investigation on Molarity Effect

    Science.gov (United States)

    Mohamad Saad, Puteri Sarah; Sutan, Hanis Binti; Sobihana Shariffudin, Shafinaz; Hashim, Hashimah; Mohd Noor, Uzer

    2015-11-01

    We have systematically investigated the current-voltage (I-V), absorbance and optical band gap of TiO2 thin film prepared through varying the molarity of the TiO2 precursor by sol-gel spin coating technique. In addition to the electrical and optical characteristics, the surface morphology was examined by using Atomic Force Microscope (AFM). From the image of the AFM, we were able to observe the uniformity of the TiO2 thin film. From the experimental results, we found that the uniformity of the TiO2 thin film is optimized at 0.2M sample. It is also found that, as the molarity increased, there is tendency of the resistivity to decrease. Not only that, the absorbance measurement and optical band gap also gave its best value for 0.2M sample. Therefore, in this work it is concluded that 0.20M of TiO2 gave the best characteristics for all measurements.

  5. Green synthesis of magnetic chitosan nanocomposites by a new sol–gel auto-combustion method

    Energy Technology Data Exchange (ETDEWEB)

    Ansari, Fatemeh [Institute of Nano Science and Nano Technology, University of Kashan, P.O. Box. 87317–51167, Kashan, Islamic Republic of Iran (Iran, Islamic Republic of); Sobhani, Azam [Department of Chemistry, Kosar University of Bojnord, Bojnord, Islamic Republic of Iran (Iran, Islamic Republic of); Salavati-Niasari, Masoud, E-mail: salavati@kashanu.ac.ir [Institute of Nano Science and Nano Technology, University of Kashan, P.O. Box. 87317–51167, Kashan, Islamic Republic of Iran (Iran, Islamic Republic of)

    2016-07-15

    The Fe{sub 2}O{sub 3}/CuFe{sub 2}O{sub 4}/chitosan nanocomposites have been successfully synthesized via a new sol–gel auto-combustion route. To prepare the nanocomposites, copper ferrite (CuFe{sub 2}O{sub 4}) and iron (II) oxide (Fe{sub 2}O{sub 3}) nanostructures were first prepared utilizing onion as a green reductant for the first time, and characterized by SEM, TEM, XRD, IR and VSM. Then chitosan was added into the nanostructures dispersed in water. Chitosan was used to functionalize and modify the nanostructures and also to improve surface properties. The nanocomposites were also characterized by several techniques including SEM, TEM, XRD, IR and VSM. The effects of amount of onion and chitosan on the morphology and particle size of nanocomposites were evaluated. - Highlights: • Fe{sub 2}O{sub 3}/CuFe{sub 2}O{sub 4}/chitosan nanocomposites were synthesized for the first time. • A simple, low-cost and friendly route was used to synthesize the nanocomposites. • Effects of amount of onion and chitosan were investigated.

  6. Luminescence properties of La2O3:Eu3+ nanophosphor prepared by sol-gel method

    Science.gov (United States)

    Pushpa, N.; Kokila, M. K.; Shivaramu, N. J.

    2016-07-01

    Undoped and Eu3+ doped La2O3 nanophosphor are synthesized by low temperature sol-gel technique. The synthesized samples are characterized by X-ray diffraction (XRD) and average crystallite size is found to be ∼18 nm and ∼23 nm for undoped and Eu3+ doped La2O3 respectively. Gamma ray irradiated undoped La2O3 shows high intense thermoluminescence (TL) glow peak at 640 K and weak TL glow peak at 443 K and the high intense peak intensity is sub linear increase with γ-dose. Whereas Eu3+ doped La2O3 nanophosphor show a prominent TL glow peak at 640 K and its TL intensity linearly increases up to 1 kGy. The kinetic parameters are estimated using glow curve deconvoluted (GCD) technique. TL emission of γ-ray irradiated Eu3+ doped La2O3 show peaks at 508, 586, 619 and 706 nm are attributed to Eu3+ transition peaks.

  7. A Comparison of Protein Extraction Methods Suitable for Gel-Based Proteomics Studies of Aphid Proteins

    Science.gov (United States)

    Few attempts have been made to methodically compare protein isolation methods from insect tissues for proteomic studies. To address this, we compared qualitative and quantitative differences among three methods for isolation, purification and solubilization of insect proteins. Schizaphis graminum,...

  8. Novel mechanisms that regulate clot structure/function.

    Science.gov (United States)

    Ariëns, Robert A S

    2016-05-01

    The structure and function of the blood clot has been associated with altered risk of thrombosis. Dense fibrin structures with small pores increase the risk of thrombosis, and have major functional consequences by increasing the resistance to fibrinolysis and altering the visco-elastic properties of the clot. However, while the structural changes to the overall fibrin network have been extensively characterised, little is known regarding the intrafibrillar structure of fibrin, the way protofibrils are arranged inside the fibrin fibers and the functional consequences of this. This brief paper aims to review recent findings regarding novel mechanisms that regulate fibrin intrafibrillar structure, including the degree of protofibril packing, their functional consequences, and the effects of FXIII activation on clot structure and thrombosis. It is concluded that fibrin intrafibrillar structure represents a major novel mechanism that influences clot structure and stability. Future studies are required to investigate the role of fibrin intrafibrillar structure in the functional characteristics of the blood clot, and in diseases of bleeding and thrombosis.

  9. Preparation and characterization of highly ordered NiO nanowire arrays by sol-gel template method

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Highly ordered nickel monoxide (NiO) nanowire arrays were fabricated by sol-gel synthesis within the pores of anodic alumina membrane (AAM).Scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) were used to characterize the topography and crystalloid structure of NiO nanowire arrays.The length and diameter of the NiO nanowires depended on the thickness of the AAM and the diameter of the pores.The results indicated that the NiO nanowires were uniformly assembled into the ordered nanopores of the AAM and paralleled to each other.Nickel monoxide nanotubes were also fabricated with the same method by changing the immersing time.This new method to prepare NiO nanowire arrays may be important from gas sensors to various engineering materials.

  10. Nanocrystalline nickel ferrite particles synthesized by non-hydrolytic sol-gel method and their composite with biodegradable polymer.

    Science.gov (United States)

    Yin, H; Casey, P S; Chow, G M

    2012-11-01

    Targeted drug delivery has been one of the most important biomedical applications for magnetic particles. Such applications require magnetic particles to have functionalized surfaces/surface coatings that facilitate their incorporation into a polymer matrix to produce a polymer composite. In this paper, nanocrystalline nickel ferrite particles with an oleic acid surface coating were synthesized using a non-hydrolytic sol-gel method and incorporated into a biodegradable polymer matrix, poly(D,L-lactide) PLA prepared using a double emulsion method. As-synthesized nickel ferrite particles had a multi-crystalline structure with chemically adsorbed oleic acid on their surface. After forming the PLA composite, nickel ferrite particles were encapsulated in PLA microspheres. At low nickel ferrite concentrations, composites showed very similar surface charges to that of PLA. The composites were magnetically responsive and increasing the nickel ferrite concentration was found to increase magnetization of the composite.

  11. Enhanced ultraviolet photocatalytic activity of Ag/ZnO nanoparticles synthesized by modified polymer-network gel method

    Science.gov (United States)

    Lu, Y. H.; Xu, M.; Xu, L. X.; Zhang, C. L.; Zhang, Q. P.; Xu, X. N.; Xu, S.; Ostrikov, K.

    2015-09-01

    Ag/ZnO nanoparticle (NP) heterostructures are synthesized through a modified polymer-network gel method in which glucose is added to the precursor solution to prevent the gel from drastically shrinking during drying of the aqueous solution. Structural and optical properties of the samples are characterized by a range of techniques including XRD, SEM, TEM, XPS, UV-Vis, and PL. The high-quality Ag-ZnO heterostructure is evidenced clearly by high-resolution TEM. The Ag/ZnO heterostructure nanocomposites exhibit a higher photocatalytic activity in the degradation of methyl orange than pure ZnO. Especially, Ag/ZnO NP heterostructures with the Ag/Zn molar ratio of 5:95 (sample ZA-5) show the highest degradation efficiency, which is 11 times higher compared with pure ZnO. The photoluminescence properties of the heterostructures and O defect states are studied to well explain the observed photocatalytic effects. ZA-5 also exhibits competitive photocatalytic activity for the degradation of other pollutant dyes such as Methylene blue and Rhodamine B compared with the recently reported techniques, while showing excellent catalyst photostability as well as offering simplicity and reliability.

  12. Enhanced ultraviolet photocatalytic activity of Ag/ZnO nanoparticles synthesized by modified polymer-network gel method

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Y. H.; Xu, M., E-mail: hsuming-2001@aliyun.com [Southwest University for Nationalities, Key Laboratory of Information Materials of Sichuan Province, School of Electrical and Information Engineering (China); Xu, L. X. [Nanyang Technological University, Plasma Sources and Applications Center, NIE (Singapore); Zhang, C. L.; Zhang, Q. P.; Xu, X. N. [Southwest University for Nationalities, Key Laboratory of Information Materials of Sichuan Province, School of Electrical and Information Engineering (China); Xu, S. [Nanyang Technological University, Plasma Sources and Applications Center, NIE (Singapore); Ostrikov, K., E-mail: kostya.ostrikov@qut.edu.au [Queensland University of Technology, Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering (Australia)

    2015-09-15

    Ag/ZnO nanoparticle (NP) heterostructures are synthesized through a modified polymer-network gel method in which glucose is added to the precursor solution to prevent the gel from drastically shrinking during drying of the aqueous solution. Structural and optical properties of the samples are characterized by a range of techniques including XRD, SEM, TEM, XPS, UV–Vis, and PL. The high-quality Ag-ZnO heterostructure is evidenced clearly by high-resolution TEM. The Ag/ZnO heterostructure nanocomposites exhibit a higher photocatalytic activity in the degradation of methyl orange than pure ZnO. Especially, Ag/ZnO NP heterostructures with the Ag/Zn molar ratio of 5:95 (sample ZA-5) show the highest degradation efficiency, which is 11 times higher compared with pure ZnO. The photoluminescence properties of the heterostructures and O defect states are studied to well explain the observed photocatalytic effects. ZA-5 also exhibits competitive photocatalytic activity for the degradation of other pollutant dyes such as Methylene blue and Rhodamine B compared with the recently reported techniques, while showing excellent catalyst photostability as well as offering simplicity and reliability.

  13. Synthesis of Spin-ladder Sr14Cu24O41 Material by Citrates Sol-gel Method

    Institute of Scientific and Technical Information of China (English)

    WANG Lili; WEI Hui; HU Ni; XIONG Rui; YU Zuxing; TANG Wufeng; SHI Jing

    2008-01-01

    A new process to synthesize polycrystailine samples of Sr14Cu24O41 was presented. Firstly, dry gel powder of Sr14Cu24O41 was synthesized by the citrates sol-gel method, using Sr(NO3)2, Cu(NO3)2, ethylene glycol and citrate acid as raw materials. Then, polycrystalline samples of Sr14Cu24O41 were prepared by solid-state reaction. Thermal Gravimetric and Differential Thermal Analysis(TG-DTA) showed that the temperature for solid-state reaction is at 942 ℃. The samples are identified to be single phase by X-ray Diffraction(XRD)and Scanning Electron Microscopy(SEM). The SEM pictures showed that the first-step particles were at even size of about 100 nm'by this technique. The electronic transport measurements showed that the doping compound were semiconductor with a crossover temperature Tρin the Arrhenius plot of the resistivity versus temprature.

  14. Durable polyorganosiloxane superhydrophobic films with a hierarchical structure by sol-gel and heat treatment method

    Science.gov (United States)

    Jiang, Zhenlin; Fang, Shuying; Wang, Chaosheng; Wang, Huaping; Ji, Chengchang

    2016-12-01

    For a surface to be superhydrophobic a combination of surface roughness and low surface energy is required. In this study, polyorganosiloxane superhydrophobic surfaces were fabricated using a sol-gel and heat treatment process followed by coating with a nanosilica (SiO2) sol and organosiloxane 1, 1, 1, 3, 5, 5, 5-heptamethyl-3-[2-(trimethoxysilyl)ethyl]-trisiloxane (β-HPEOs). The nano-structure was superimposed using self-assembled, surface-modified silica nanoparticles, forming two-dimensional hierarchical structures. The water contact angle (WCA) of polyorganosiloxane superhydrophobic surface was 143.7 ± 0.6°, which was further increased to 156.7 ± 1.1° with water angle hysteresis of 2.5 ± 0.6° by superimposing nanoparticles using a heat treatment process. An analytical characterization of the surface revealed that the nano-silica and polyorganosiloxane formed a micro/nano structure on the films and the wetting behaviour of the films changed from hydrophilic to superhydrophobic. The WCA of these films were 143.7 ± 0.6° and at heat treatment temperatures of less than 400 °C, the WCA increased from 144.5 ± 0.7° to 156.7 ± 1.1°. The prepared superhydrophobic films were stable even after heat treatment at 430 °C for 30 min and their superhydrophobicity was durable for more than 120 days. The effects of heat treatment process on the surface chemistry structure, wettability and morphology of the polyorganosiloxane superhydrophobic films were investigated in detail. The results indicated that the stability of the chemical structure was required to yield a thermally-stable superhydrophobic surface.

  15. Water repellent porous silica films by sol-gel dip coating method.

    Science.gov (United States)

    Rao, A Venkateswara; Gurav, Annaso B; Latthe, Sanjay S; Vhatkar, Rajiv S; Imai, Hiroaki; Kappenstein, Charles; Wagh, P B; Gupta, Satish C

    2010-12-01

    The wetting of solid surfaces by water droplets is ubiquitous in our daily lives as well as in industrial processes. In the present research work, water repellent porous silica films are prepared on glass substrate at room temperature by sol-gel process. The coating sol was prepared by keeping the molar ratio of methyltriethoxysilane (MTES), methanol (MeOH), water (H(2)O) constant at 1:12.90:4.74, respectively, with 2M NH(4)OH throughout the experiments and the molar ratio (M) of MTES/Ph-TMS was varied from 0 to 0.22. A simple dip coating technique is adopted to coat silica films on the glass substrates. The static water contact angle as high as 164° and water sliding angle as low as 4° was obtained for silica film prepared from M=0.22. The surface morphological studies of the prepared silica film showed the porous structure with pore sizes typically ranging from 200nm to 1.3μm. The superhydrophobic silica films prepared from M=0.22 retained their superhydrophobicity up to a temperature of 285°C and above this temperature the films became superhydrophilic. The porous and water repellent silica films are prepared by proper alteration of the Ph-TMS in the coating solution. The prepared silica films were characterized by surface profilometer, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier Transform Infrared (FT-IR) spectroscopy, humidity tests, chemical aging tests, static and dynamic water contact angle measurements.

  16. Preparation of nickel and Ni{sub 3}Sn nanoparticles via extension of conventional citric acid and ethylene diamine tetraacetic acid mediated sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Li, Pingyun, E-mail: lpyljr@126.com; Deng, Guodong; Guo, Xiaode; Liu, Hongying; Jiang, Wei; Li, Fengsheng

    2016-05-25

    This work aims to extend the application field of sol–gel process from conventional oxides, carbides, sulfides to metallic nanocrystalline materials. Metallic ions were coordinated with chelating agents of citric acid (CA) and ethylene diamine tetraacetic acid (EDTA) in aqueous solution. Then the solutions were dried at 383 K, resulting in the formation of sol and gel. Heating treatments of dried gels were then carried out with protection of N{sub 2} atmosphere. Ni and Ni{sub 3}Sn alloy nanoparticles were obtained by this sol–gel method in the range of 623–823 K. The as-prepared Ni and Ni{sub 3}Sn alloy nanoparticles have average grain sizes of 15 and 30 nm, and have face-centred-cubic (fcc) crystalline phase. Our results provide new insight into the application of conventional sol–gel method. - Graphical abstract: Sol–gel method is conventionally applied to prepare oxides, carbides, and sulfides. In this work, the application field of sol–gel method is extended to metallic nanoparticles. By using citric acid (CA) and ethylene diamine tetraacetic acid (EDTA) mediated sol–gel method, metallic Ni (a and c) and Ni{sub 3}Sn (b and d) alloy nanoparticles can be prepared when the heating treatments are performed under N{sub 2} protecting atmosphere. The Ni and Ni{sub 3}Sn nanoparticles have face-centered-cubic (fcc) crystalline phase and ultrafine grain sizes. Diffraction peaks of (110) superstructure reflection plane of Ni{sub 3}Sn nanoparticles can also be observed in Figure b, which can be considered as direct evidence of formation of alloy crystalline phase by performing this sol–gel method. - Highlights: • Ni and Ni{sub 3}Sn alloy nanoparticles have been prepared by sol–gel processes. • Citric acid and ethylene diamine tetraacetic acid were applied as chelating agent. • Diffraction peak of superstructure reflection plane of Ni{sub 3}Sn was detected by XRD. • A novel strategy for preparation of alloy nanoparticles has been presented.

  17. {sup 90}Y microspheres prepared by sol-gel method, promising medical material for radioembolization of liver malignancies

    Energy Technology Data Exchange (ETDEWEB)

    Łada, Wiesława, E-mail: w.lada@ichtj.waw.pl [Institute of Nuclear Chemistry and Technology, 03-195 Warsaw, Dorodna 16 (Poland); Iller, Edward [National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Andrzej Sołtan 7 (Poland); Wawszczak, Danuta [Institute of Nuclear Chemistry and Technology, 03-195 Warsaw, Dorodna 16 (Poland); Konior, Marcin, E-mail: marcin.konior@polatom.pl [National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Andrzej Sołtan 7 (Poland); Dziel, Tomasz [National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Andrzej Sołtan 7 (Poland)

    2016-10-01

    A new technology for the production of radiopharmaceutical {sup 90}Y microspheres in the form of spherical yttrium oxide grains obtained by sol-gel method has been described. The authors present and discuss the results of investigations performed in the development of new production technology of yttrium microspheres and determination of their physic-chemical properties. The final product has the structure of spherical yttrium oxide grains with a diameter 25–100 μm, is stable and free from contaminants. Irradiation of 20 mg samples of grains with diameter of 20–50 μm in the thermal neutron flux of 1.7 × 10{sup 14} cm{sup −2} s{sup −1} at the core of MARIA research nuclear reactor allowed to obtain microspheres labelled with the {sup 90}Y isotope on the way of the nuclear reaction {sup 89}Y(n, γ){sup 90}Y. Specific activity of irradiated microspheres has been determined by application of absolute triple to double coincidence ratio method (TDCR) and has been evaluated at 190 MBq/mg Y. {sup 90}Y microspheres prepared by the proposed technique can be regarded as a promising medical material for radioembolization of liver malignancies. - Highlights: • Sol-gel methods for preparation of spherical yttrium trioxide grains have been proposed. • Determination condition for irradiation {sup 89}Y{sub 2}O{sub 3} grains in nuclear reactor • Evaluation of specific activity of {sup 90}Y microspheres • Estimation of {sup 90}Y microspheres as promising medical material for radioembolization.

  18. An ecofriendly green liquid chromatographic method for simultaneous determination of nicotinamide and clindamycin phosphate in pharmaceutical gel for acne treatment

    Directory of Open Access Journals (Sweden)

    Fawzia Ibrahim

    2017-07-01

    Full Text Available A new green micellar liquid chromatographic method was developed and validated for the quantitative estimation of nicotinamide (NICO and clindamycin phosphate (CLD in bulk and pharmaceutical gel formulation. The analytes are well resolved in less than 6.0 minutes using micellar mobile phase consisting of 0.10M sodium dodecyl sulfate (SDS, 0.3% triethylamine, and 10% 2-propanol in 0.02M orthophosphoric acid at pH 3.0, running through an Eclipse XDB-C8 column (150 mm×4.6 mm, 5 μm particle size with flow rate 1.0 mL/min. The effluent was monitored with diode array detection at 210 nm. The retention times of NICO and CLD were 3.8 minutes and 5.6 minutes, respectively. The method was validated according to the International Conference on Harmonisation (ICH guidelines in terms of linearity, limit of detection, limit of quantification, accuracy, precision, robustness, and specificity to prove its reliability. Linear correlation was achieved by plotting the peak area of each drug against its concentration. It was found to be rectilinear in the ranges of 1.0–40.0 μg/mL and 0.5–15.0 μg/mL with limits of detection of 0.06 μg/mL and 0.03 μg/mL and limits of quantification of 0.19 μg/mL and 0.09 μg/mL for NICO and CLD, respectively. The method was successfully implemented for the simultaneous determination of the analytes in their bulk powder and combined gel formulation with high % recoveries. The ease of sample treatment facilitates and greatly expedites the treatment with reduced cost and improved accuracy of the procedure.

  19. ELECTRON MICROSCOPIC INVESTIGATION OF YTTRIUM ALUMINUM GARNET POWDERS Y3AL5O12, SYNTHESIZED BY SOL–GEL METHOD

    Directory of Open Access Journals (Sweden)

    A. E. Baranchikov

    2015-09-01

    Full Text Available Subject of Study. The paper presents results of characterization for neodymium doped yttrium aluminum garnet nanopowders - YAG:Nd3+ by the method of scanning electronic microscopy. Method. Synthesis of YAG:Nd3+ was carried out by sol-gel method from nitrate or acetate - nitrate solutions with addition of some organic compounds and ammonia as well. Such substances were used as the source ones: oxides of neodymium and yttrium with the content of the basic substance equal to 99.999 %; organic compounds: citric acid with the content of the basic substance not less than 99.0 %; ethylene glycol (99.5%; the ammonium lauryl sulfate (99.0 %; urea (99.0 % of Alfa Aesar, Fluka, Aldrich companies. Oxides of yttrium and neodymium (5 at. % were dissolved in 50% acetic acid, nitrate aluminum was added with a view to the resulting product Y2,85Nd0,15Al5,0O12, the solution was stirred and heated to 60С before reaching its transparency and uniformity. The weight of the portion corresponding to the stoichiometry YAG was 2.0 g. 50 % aqueous solutions of organic substances or 5% NH4OH in a weight ratio of 1:1 to the weight of the garnet were added in aqueous solutions, placed into glass cups. The solutions were thoroughly mixed first using a conventional stirrer, then on ultrasonic installation with simultaneous 60 С heating for 2 hours. Drying of solutions to the consistency of a powder or a thick gel was carried out at 110 С. Then the samples were placed into platinum cups and annealed in a tube furnace at 950 - 1050 С for the period from 0.5 to 2 hours. Additional annealing of the powders in the air at 950 - 1060С were carried out for the purpose of powders clarifying for residual amorphous carbon removal. Main Results. The synthesized powder precursors and powders after annealing were examined using a polarizing microscope to identify anisotropic crystalline phases. X-ray analysis of the synthesized samples was carried out on a DRON - 4 and UDR - 63

  20. Unusual clotting dynamics of plasma supplemented with iron(III).

    Science.gov (United States)

    Jankun, Jerzy; Landeta, Philip; Pretorius, Etheresia; Skrzypczak-Jankun, Ewa; Lipinski, Bogusław

    2014-02-01

    Iron salts are used in the treatment of iron deficiency anemia. Diabetic patients are frequently anemic and treatment includes administration of iron. Anemic patients on hemodialysis are at an increased risk of thromboembolic coronary events associated with the formation of dense fibrin clots resistant to fibrinolysis. Moreover, in chronic kidney disease patients, high labile plasma iron levels associated with iron supplementation are involved in complications found in dialyzed patients such as myocardial infarction. The aim of the present study was to investigate whether iron treatment is involved in the formation of the fibrin clots. Clotting of citrated plasma supplemented with Fe(3+) was investigated by thromboelastometry and electron microscopy. The results revealed that iron modifies coagulation in a complex manner. FeCl(3) stock solution underwent gradual chemical modification during storage and altered the coagulation profile over 29 days, suggesting that Fe(3+) interacts with both proteins of the coagulation cascade as well as the hydrolytic Fe(3+) species. Iron extends clotting of plasma by interacting with proteins of the coagulation cascade. Fe(3+) and/or its hydrolytic species interact with fibrinogen and/or fibrin changing their morphology and properties. In general FeCl(3) weakens the fibrin clot while at the same time precipitating plasma proteins immediately after application. Fe(3+) or its derivatives induced the formation of insoluble coagulums in non-enzymatic reactions including albumin and transferrin. Iron plays a role in coagulation and can precipitate plasma proteins. The formation of coagulums resistant to lysis in non‑enzymatic reactions can increase the risk of thrombosis, and extending clotting of plasma can prolong bleeding.

  1. Effects of sol-gel method and lanthanum addition on catalytic performances of nickel-based catalysts for methane reforming with carbon dioxide

    Institute of Scientific and Technical Information of China (English)

    LI Xiancai; HU Quanhong; YANG Yifeng; CHEN Juanrong; LAI Zhihua

    2008-01-01

    The nickel-based catalysts were prepared by the sol-gel method and used for the CH4 reforming with CO2. The effects of the sol-gel method on the specific surface area, catalytic activity, desorption, and reduction performances of catalysts were investigated with BET, TPR, and TPD. Compared with the catalyst prepared by the impregnation method, the results indicated that the catalysts prepared by the sol-gel method had larger specific surface area, showing higher catalytic activities and exhibiting perfect desorption and reduction per-formances. In addition, the modification effects of adding La were studied, and it was found that the 0.75NLBT catalyst constituted of 5wt.%Ni-0.75wt.%La was optimal.

  2. A new separation and preconcentration method for selenium in some foods using modified silica gel with 2,6-diamino-4-phenil-1,3,5-triazine.

    Science.gov (United States)

    Mendil, Durali; Demirci, Zafer; Uluozlu, Ozgur Dogan; Tuzen, Mustafa; Soylak, Mustafa

    2017-04-15

    A novel and simple solid phase extraction method was improved and recommended for selenium. Silica gel was modified with 2,6-diamino-4-phenil-1,3,5-triazine and characterized by FTIR, SEM and elemental analysis and used adsorbent for column solid phase extraction of selenium ions. The experimental parameters (pH, flow rates, amounts of the modified silica gel, concentration and type of eluent, volume of sample, etc.) on the recoveries of selenium were optimized. Standard reference materials were analyzed for validation of method. The present method was successfully applied to the detection of total selenium in water and microwave digested some food samples with quantitative recoveries (> 95%). The relative standard deviations weresilica gel was 5.90mgg(-1). The LOD was 0.015μgL(-1). Enrichment factor was obtained as 50 for the introduced method.

  3. Real-time monitoring of human blood clotting using a lateral excited film bulk acoustic resonator

    Science.gov (United States)

    Chen, Da; Wang, Jingjng; Wang, Peng; Guo, Qiuquan; Zhang, Zhen; Ma, Jilong

    2017-04-01

    Frequent assay of hemostatic status is an essential issue for the millions of patients using anticoagulant drugs. In this paper, we presented a micro-fabricated film bulk acoustic sensor for the real-time monitoring of blood clotting and the measurement of hemostatic parameters. The device was made of an Au/ZnO/Si3N4 film stack and excited by a lateral electric field. It operated under a shear mode resonance with the frequency of 1.42 GHz and had a quality factor of 342 in human blood. During the clotting process of blood, the resonant frequency decreased along with the change of blood viscosity and showed an apparent step-ladder curve, revealing the sequential clotting stages. An important hemostatic parameter, prothrombin time, was quantitatively determined from the frequency response for different dilutions of the blood samples. The effect of a typical anticoagulant drug (heparin) on the prothrombin time was exemplarily shown. The proposed sensor displayed a good consistency and clinical comparability with the standard coagulometric methods. Thanks to the availability of direct digital signals, excellent potentials of miniaturization and integration, the proposed sensor has promising application for point-of-care coagulation technologies.

  4. Preparation and characterization of 5-sulphosalicylic acid doped tetraethoxysilane composite ion-exchange material by sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Rehman, Suhail-ul; Islam, Nasarul; Ahad, Sozia; Fatima, Syed Zeeshan; Pandith, Altaf Hussain, E-mail: altafpandit23@gmail.com

    2013-09-15

    Highlights: • Sulphosalicylic acid doped tetraethoxysilane composite is prepared by sol–gel method. •Its X-ray diffraction studies suggest that it is crystalline in nature. • This material shows selectivity for Mg(II) and Ni(II) ions in aqueous solutions. • Separation of Ni(II) from binary mixtures was successfully achieved on this material. -- Abstract: In this manuscript, we report the preparation and characterization of sulphosalicylic doped tetraethoxysilane (SATEOS), composite material by sol–gel method as a new ion exchanger for the removal of Ni(II) from aqueous solution. The fine granular material was prepared by acid catalyzed condensation polymerization through sol–gel mechanism in the presence of cationic surfactant. The material has an ion exchange capacity of 0.64 mequiv./g(dry) for sodium ions, 0.60 mequiv./g(dry) for potassium ions, 1.84 mequiv./g(dry) for magnesium ions, 1.08 mequiv./g(dry) for calcium ions and 1.36 mequiv./g(dry) for strontium ions. Its X-ray diffraction studies suggest that it is crystalline in nature. The material has been characterized by SEM, IR, TGA and DTG so as to identify the various functional groups and ion exchange sites present in this material. Quantum chemical computations at DFT/B3LYP/6-311G (d,p) level on model systems were performed to substantiate the structural conclusions based ion instrumental techniques. Investigations into the elution behaviour, ion exchange reversibility and distribution capacities of this material towards certain environmentally hazardous metal ions are also performed. The material shows good chemical stability towards acidic conditions and exhibits fast elution of exchangeable H{sup +} ions under neutral conditions. This material shows remarkable selectivity for Ni(II) and on the basis of its K{sub d} value (4 × 10{sup 2} in 0.01 M HClO{sub 4}) some binary separations of Ni(II) from other metal ions are performed.

  5. Synthesis of novel perovskite crystal structure phase of strontium doped rare earth manganites using sol gel method

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Latif, I.A. [Physics Department, College of Science, Najran University, P.O. 1988, Najran (Saudi Arabia); Reactor Physics Department, NRC, Atomic Energy Authority, Abou Zabaal, P.O. 13759, Cairo (Egypt); Ismail, Adel A., E-mail: adelali141@yahoo.com [Advanced Materials and Nano-Research Centre, Najran University, P.O. Box 1988, Najran 11001 (Saudi Arabia); Central Metallurgical Research & Development Institute (CMRDI), Helwan 11421, Cairo (Egypt); Bouzid, Houcine [Advanced Materials and Nano-Research Centre, Najran University, P.O. Box 1988, Najran 11001 (Saudi Arabia); Al-Hajry, A. [Physics Department, College of Science, Najran University, P.O. 1988, Najran (Saudi Arabia); Advanced Materials and Nano-Research Centre, Najran University, P.O. Box 1988, Najran 11001 (Saudi Arabia)

    2015-11-01

    In the present work, polycrystalline perovskites of R{sub 0.6}Sr{sub 0.4}MnO{sub 3} nanocomposites (R=La, Nd, or Sm) were synthesized using the sol–gel method in the presence of citric acid and polyethylene glycol as chelating and structure directing agents respectively. The synthesized gel was calcined at 800 °C for 5 h. The XRD revealed that the obtained nanocrystalline R{sub 0.6}Sr{sub 0.4}MnO{sub 3} is monoclinic crystal structure of space group (I2/a). TEM images showed that the prepared perovskites are homogeneous and uniform with particle sizes in a range 20–40 nm and the HR-TEM images and lattice fringes displayed the monoclinic structure. IV measurements showed that Nd{sub 0.6}Sr{sub 0.4}MnO{sub 3} has semiconducting properties at room temperature. With applying low magnetic field, a transition from semiconductor behavior to Ohmic resistivity was observed. The static resistance of Nd{sub 0.6}Sr{sub 0.4}MnO{sub 3} was calculated to be ~2.985 TΩ for semiconductor phase and the resistance increased 1000 times that gives rise to negative magnetoresistance (MR). The value of MR of Nd{sub 0.6}Sr{sub 0.4}MnO{sub 3} equals to 99.84%, which leads to the use of these materials in fabrication of magnetic devices in the industrial scale. - Highlights: • Polycrystalline perovskites of R{sub 0.6}Sr{sub 0.4}MnO{sub 3} were synthesized using the sol–gel method. • The XRD analysis showed the prepared perovskites are monoclinic crystal structure. • The prepared perovskites are homogeneous and uniform with particles size (20–40 nm). • IV measurements displayed that Nd{sub 0.6}Sr{sub 0.4}MnO{sub 3} has semiconducting properties. • The value of MR equals to 99.84% in Nd{sub 0.6}Sr{sub 0.4}MnO{sub 3}.

  6. Luminescence Properties of Tb3+-Doped LuAG Films Prepared by Pechini Sol-Gel Method

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Lu3Al5O12 (LuAG) thin films with different Tb3+ concentration were prepared on carefully cleaned (111) silicon wafer by a Pechini process and dip-coating technique. Heat treatment was performed in the temperature range from 800 to 1100 ℃. The crystal structure was analyzed by XRD. The results show that LuAG film starts to crystallize at about 900 ℃, and the particle size increases with the sintering temperature. Excitation and emission spectra of Tb3+ doped LuAG films were measured. The effects of heat-treatment temperature and doping concentration of Tb3+ on the luminescent properties were also investigated. For a comparison study, Tb3+-doped LuAG powders were also prepared by the same sol-gel method.

  7. Synthesis and characterization of mixture of nanozirconia and nanosilica obtained from commercially available zircon flour by sol–gel method

    Indian Academy of Sciences (India)

    A J K Prasad; S M Shashidhara; B K Muralidhara

    2011-12-01

    In this paper we present the results of our patented (application filed in India) process for synthesizing a mixture of nanozirconia and nanosilica, obtained by the sol–gel method from commercially available zircon flour and hydrofluoric acid at low temperatures (∼ 100°C). Within the scope of this study, 99.2% dissolution of zircon was obtained by using 40% HF for a solid–liquid (S/L) ratio of 0.05 for a digestion period of 120 h. The nanoparticles, characterized by XRD, SEM and TEM techniques, were found to be largely spherical in shape and the average size of the particles was found to be less than 5 nm. Within the product, zirconiarich and silica-rich regions were found to exist.

  8. Electrical stability of Al-doped ZnO transparent electrode prepared by sol-gel method

    Science.gov (United States)

    Tabassum, Samia; Yamasue, Eiji; Okumura, Hideyuki; Ishihara, Keiichi N.

    2016-07-01

    Al-doped zinc oxide (AZO) thin films have been considered as a promising alternative to tin doped indium oxide (ITO), which is currently used in various optoelectronic applications. However, the environmental stability of AZO film is not satisfactory, in that the resistivity is significantly increases in air. Here, we investigate the resistivity stability of AZO thin films prepared by sol-gel method using various annealing temperatures and durations. The degradation of resistivity property was observed for AZO films stored in ambient or damp heat environment, where the degradation rate was influenced by annealing temperature. A significant improvement of electrical stability was attained in AZO films that were prepared at high annealing temperature. The films, which showed the highest and the lowest increasing rate of resistivity, were further characterized in detail to shed light on the possible mechanisms explaining the improved stability through crystallinity, surface morphology and elemental state of the thin film.

  9. Synthesis of FeNi Alloy Nanomaterials by Proteic Sol-Gel Method: Crystallographic, Morphological, and Magnetic Properties

    Directory of Open Access Journals (Sweden)

    Cássio Morilla dos Santos

    2016-01-01

    Full Text Available Proteic Sol-Gel method was used for the synthesis of FeNi alloy at different temperature conditions and flow reduction. The solids were characterized by XRD, H2-TPR, SEM, TEM, Mössbauer spectroscopy, and VSM. It was observed by X-ray diffraction pure FeNi alloy in the samples reduced at 600°C (40 mL/min H2 flow and 700°C (25 mL/min H2 flow. The FeNi alloy presented stability against the oxidizing atmosphere up to 250°C. The morphology exhibited agglomerates relatively spherical and particles in the range of 10–40 nm. Mössbauer spectroscopy showed the presence of disordered ferromagnetic FeNi alloy, and magnetic hysteresis loop revealed a typical behavior of soft magnetic material.

  10. Electrical characterization of ZnO/NiO p-n junction prepared by the sol-gel method

    Science.gov (United States)

    Merih Akyuzlu, A.; Dagdelen, Fethi; Gultek, Ahmet; Hendi, A. A.; Yakuphanoglu, Fahrettin

    2017-04-01

    ZnO and NiO films were synthesized on fluourine-doped tin oxide (FTO) glass substrate by the sol-gel method. The surface morphology of the films was investigated by atomic force microscopy. The optical band gaps of the ZnO and NiO films were found to be 3.198 and 3.827eV, respectively. A ZnO/NiO p-n junction diode was prepared and electrical charge transport mechanism of the diode was analyzed using thermionic emission and Norde functions. The ideality factor, barrier height and series resistance of the diode were determined to be 6.46, 1.036eV and 39.1 M {Ω} , respectively. The obtained results indicate that ZnO/NiO p-n junction can be used as transparent diode for optic communications.

  11. Bactericidal and Photocatalytic Activity of Fe3+- TiO2 Thin Films Prepared by the Sol-gel Method

    Institute of Scientific and Technical Information of China (English)

    WANG Xun; GONG Wenqi

    2008-01-01

    Pure TiO2 thin films and iron doped TiO2 thin films on glass substrate were prepared by sol-gel method, and characterized by X-ray diffractometer (XRD), thermo-gravimetric analysis (TG-DSC), high resolution transmission electron microscope (HRTEM), scanning electron microscope (SEM) and UV-Vis spectroscopy, respectively. The experimental results show that the pure TiO2 thin films and iron doped TiO2 thinfilms can destroy most of the eseheriehia coli and bacillus subtillis under the irradiation of 365 nm UV-light.However, the iron doped TiO2 thin film is a better photocatalyst than pure TiO2 thin film. The ultrastructural studies provide direct evidences for understanding the bactericidal mechanism of the TiO2 photocatalyst.

  12. Preparation of silane-WO{sub 3} film through sol-gel method and characterization of photochromism

    Energy Technology Data Exchange (ETDEWEB)

    Luo Zhongkuan [College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060, Guangdong (China)], E-mail: luozhongkuan@126.com; Yang Jianjun [Xinyi Glass Holdings Limited, Shenzhen 518115, Guangdong (China); Cai Honghua; Li Haiyang; Ren Xiangzhong; Liu Jianhong; Liang Xun [College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060, Guangdong (China)

    2008-06-30

    The sol of silane and WO{sub 3} was prepared from tetraethyl orthosilicate (TEOS) and methacryloxy-propyl-trimethoxy silane (KH570) with a novel route as described in previous work, and the aqueous WO{sub 3} solution was prepared from ammonium tungstate. These two sols were mixed by stirring for about 1 hour with a certain ratio. Through sol-gel method, the transparent hybrids coating of organic silane and tungsten oxide was prepared by spraying or dipping on the glass substrates, and then were heat-treated at a certain temperature. The photochromic properties were investigated. AFM was used to investigate the surface structure of the prepared coatings. The crystalline phase was studied through X-ray diffraction. UV lights with different wavelengths were used to get the coloration of the film. The results show that silane-WO{sub 3} film exhibits better photo-chromic properties under UV light irradiation.

  13. Synthesis and characterization of LiFePO4/C cathode materials by sol-gel method.

    Science.gov (United States)

    Liu, Shuxin; Yin, Hengbo; Wang, Haibin; Wang, Hong

    2014-09-01

    The carbon coated LiFePO4 cathode materials (LiFePO4/C) were successfully synthesized by sol-gel method with glucose, citric acid and PEG-4000 as dispersant and carbon source, respectively. The microstructure and grain size of LiFePO4/C composite were characterized by X-ray diffraction, Raman spectroscopy, transmission electron microscopy. The results showed that the carbon source and calcination temperature had important effect on the graphitization degree of carbon; the carbon decomposed by citric acid had higher graphitization degree; with calcination temperature rising, the graphitization degree of carbon increased and the particles size increased. The graphitization degree and grain size were very important for improving the electrochemical performance of LiFePO4 cathode materials, according to the experimental results, the sample LFP-700 (LFP-C) which was synthesized with citric acid as dispersant at 700 degree C had lower polarization and larger discharge capacity.

  14. Preparation and properties of luminous materials of CaSiO3:Pb, Mn by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    YANG Liangzhun; FANG Min; Liu Yuejiao; LIU Chao; WANG Xiuying; YU Xibin

    2007-01-01

    The luminous materials of CaSiO3: Pb, Mn were synthesized by sol-gel method and ultrasound technology.The properties of the phosphors were characterized by luminescence spectrum, differential thermal analysis and thermal gravimetry analysis (DTA-TG), X-ray diffraction(XRD), Fourier transform infrared spectrometer (FT-IR)and transmission electron microscopy (TEM). The effects of factors such as the synthetic material compositions,ultrasound time and annealed temperature on phosphorescent brightness of sample were studied and the optimum synthetic conditions were determined. The results show that, compared with the sample made by the high temperature solid-state reaction, the luminescent intensity of the CaSiO3:Pb, Mn sample increased by about 200% and the mean diameter of particles of the sample decreased by about 300 nm.

  15. Studies of ferroelectric and dielectric properties of pure and doped barium titanate prepared by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Bisen, Supriya; Mishra, Ashutosh; Jarabana, Kanaka M. [School of Physics, Vigyan Bhawan, Devi Ahilya University, Khandwa Road Indore-452001 (India)

    2016-05-23

    In this work, Barium Titanate (BaTiO{sub 3}) powders were synthesized via Sol-Gel auto combustion method using citric acid as a chelating agent. We study the behavior of ferroelectric and dielectric properties of pure and doped BaTiO{sub 3} on different concentration. To understand the phase and structure of the powder calcined at 900°C were characterized by X-ray Diffraction shows that tetragonal phase is dominant for pure and doped BTO and data fitted by Rietveld Refinement. Electric and Dielectric properties were characterized by P-E Hysteresis and Dielectric measurement. In P-E measurement ferroelectric loop tracer applied for different voltage. The temperature dependant dielectric constant behavior was observed as a function of frequency recorded on hp-Hewlett Packard 4192A, LF impedance, 5Hz-13Hz analyzer.

  16. Fabrication and characterization of uniform TiO2 nanotube arrays by sol–gel template method

    Indian Academy of Sciences (India)

    T Maiyalagan; B Viswanathan; U V Varadaraju

    2006-12-01

    TiO2 nanotubes have been synthesized by sol–gel template method using alumina membrane. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, UV absorption spectrum and X-ray diffraction techniques have been used to investigate the structure, morphology and optical properties of TiO2 nanotubes. SEM image showed that TiO2 nanotubes obtained were ordered and uniform. The diameter and length of the nanotubes were decided by the pore size and thickness of alumina template. Raman and XRD measurements confirmed the crystallinity and anatase phase of the TiO2 nanotubes. The optical absorption measurement of TiO2 nanotubes exhibits a blue shift with respect to that of the bulk TiO2 owing to the quantum size effect.

  17. Characterisation and thermal properties of titanium dioxide nanoparticles-containing biodegradable polylactide composites synthesized by sol-gel method.

    Science.gov (United States)

    Mhlanga, Nikiwe; Ray, Suprakas Sinha

    2014-06-01

    This study reports the synthesis, characterisation and thermal properties of polylactide (PLA)/titanium dioxide nanoparticles (TiO2 NPs) composites using the sol-gel method. The percentage weight of TiO2 NP sol was varied from 3, 8, 11 and 14. The synthesised composites were characterised using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction, energy dispersive X-ray spectroscopy (EDS), thermogravimetric analysis and dynamic mechanical analysis. Encapsulation of the TiO2 into the PLA matrix was attainable based on the SEM images and the FTIR and EDS results. The thermal stability of the composites was shifted to lower temperatures due to photodegradation induced by the metal oxide on the PLA chain. Both PLA and TiO2 NPs have potential in drug delivery because of their biocompatibility and biodegradability.

  18. Bioactive nanocrystalline wollastonite synthesized by sol–gel combustion method by using eggshell waste as calcium source

    Indian Academy of Sciences (India)

    U Anjaneyulu; S Sasikumar

    2014-04-01

    The sol–gel combustion method was employed to synthesize the nanocrystalline wollastonite by taking the raw eggshell powder as a calcium source and TEOS as a source of silicate. Glycine was used as a reductant or fuel and nitrate ions present in metal nitrate acts as an oxidizer. The phase purity of the wollastonite was analysed by powder XRD and the product is found to contain single-phasic wollastonite. FT–IR spectrum shows the characteristic peaks of the functional groups present in the wollastonite. SEM images show that particles are agglomerated and the particle size is found to be in the nanoregime. The calcination temperature was optimized based on the thermal analysis of the precursor. The bioactivity of wollastonite was investigated by immersing the scaffold in a simulated body fluid for 15 days at 37°C and intermediate analysis of the surface by XRD shows the deposition of hydroxyapatite layer after 5 days.

  19. Structural and optical properties of Ni added ZnO thin films deposited by sol-gel method

    Science.gov (United States)

    Murugan, R.; Vijayaprasath, G.; Mahalingam, T.; Anandhan, N.; Ravi, G.

    2014-04-01

    Pure and Ni added zinc oxide thin films were prepared by sol-gel method using spin-coating technique on glass substrates. The influences of nickel on ZnO thin films are characterized by Powder X-ray diffraction study. Pure and Ni added thin films are hexagonal wurtzite structure without any secondary phase in c-axis orientation. The SEM images of thin films show uniform sphere like particles covered completely on glass substrates. All the films exhibit transmittance of 85-95% in the visible range up to 800nm and cut-off wavelength observed at 394 nm corresponding to the fundamental absorption of ZnO. The photoluminescence property for pure and Ni added ZnO thin films has been studied and results are presented in detail.

  20. Comparison between sol-gel derived and classic methods for the elaboration process of DSA Ta/IrO{sub 2} electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Massot, L.; Palau, P.; Savall, A.; Taxil, P. [Paul-Sabatier Univ., Toulouse (France). Chemical Engineering Lab.

    2006-07-01

    This paper investigated the oxygen evolution of inert anodes in acidic media. The electrodes were composed of a tantalum (Ta) substrate with a catalyst coating of iridium oxide (IrO{sub 2}). Two methods were used to obtain the catalyst coating: (1) a Sol-Gel derived method using iridium acetylacetonate ([CH{sub 3}COCH=COCH{sub 3}]{sub 3}Ir) dissolved in an isopropanol-acetic acid mixture, and (2) iridium chloride (IrCl{sub 4}) dissolved in an ethanol-isopropanol mixture as an iridium oxide precursor. The electrodes were then characterized and compared using thermogravimetric measurements of the precursors. Results of the study showed that the new precursor derived from the Sol-Gel method was more reactive as the IrO{sub 2}3 formation temperature was lower. A higher amount of heat generated by cracking and combustion of the organic compounds was released during the decomposition of the Sol-Gel precursor salts. The enthalpy of conversion into the oxide measured by differential sweeping calorimetry was -15580 J/g in the case of the Sol-Gel derived method and -74.7 J/g in the case of the traditional method. However, the electrodes prepared by the Sol-Gel method were not stable, and the service lives of the electrodes were 4 times less significant than those of the electrodes prepared using the other method due to the low stability of metal iridium under polarization. It was also noted that the fine catalyst particles were less stable during a gaseous evolution. Results indicated that a rise in the thermal processing temperatures may facilitate the formation of iridium oxide, but would involve a more significant oxidation of the substrate. It was concluded that the Sol-Gel method is not suitable for the preparation of Ta/IrO{sub 2} electrodes when the oxidation number of the iridium oxide precursor is 3. 3 refs., 1 tab., 1 fig.

  1. Influence of Experimental Parameters Using the Dip-Coating Method on the Barrier Performance of Hybrid Sol-Gel Coatings in Strong Alkaline Environments

    Directory of Open Access Journals (Sweden)

    Rita B. Figueira

    2015-04-01

    Full Text Available Previous studies have shown that the barrier effect and the performance of organic-inorganic hybrid (OIH sol-gel coatings are highly dependent on the coating deposition method as well as on the processing conditions. However, studies on how the coating deposition method influences the barrier properties in alkaline environments are scarce. The aim of this experimental research was to study the influence of experimental parameters using the dip-coating method on the barrier performance of an OIH sol-gel coating in contact with simulated concrete pore solutions (SCPS. The influence of residence time (Rt, a curing step between each dip step and the number of layers of sol-gel OIH films deposited on hot-dip galvanized steel to prevent corrosion in highly alkaline environments was studied. The barrier performance of these OIH sol-gel coatings, named U(400, was assessed in the first instants of contact with SCPS, using electrochemical impedance spectroscopy and potentiodynamic methods. The durability and stability of the OIH coatings in SCPS was monitored during eight days by macrocell current density. The morphological characterization of the surface was performed by Scanning Electronic Microscopy before and after exposure to SCPS. Glow Discharge Optical Emission Spectroscopy was used to investigate the thickness of the U(400 sol-gel coatings as a function of the number of layers deposited with and without Rt in the coatings thickness.

  2. Structural, Optical and EXAFS Studies of Nickel Substituted Copper Ferrites Nano-Particle by Sol-Gel Auto Combustion Method

    Science.gov (United States)

    Mishra, Ashutosh; khan, Mehjabeen; Jarabana, Kanaka M.; Bisen, Supriya

    2016-10-01

    The Cu-Ni ferrites with general formula Cu1-xNixFe2O4 (where x=0.0, 0.1, 0.2, 0.3) were prepared by sol gel method. The Extended X-ray absorption fine structure (EXAFS), X- ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) measurements were carried out. EXAFS spectra have been recorded at the k edge of Iron using the dispersive EXAFS (DEXAFS) beam line at 2.5 GeV at Indus -2 synchrotron radiation source RRCAT, Indore, India. The EXAFS data have been analyzed using the computer software Athena. These have been used to determine the bond lengths in these ferrites with the help of three different methods, namely, Levy's, Lytle's and Lytle, Sayers and Stern's (LSS) methods. The phase uncorrected bond lengths have also been obtained from Fourier transformation method and the results obtained have been compared with the results obtained from LSS method, which also gives phase uncorrected bond lengths. XRD shows the structure is the tetragonal, and FTIR was used to determine the nature of the vibrational modes present in the system.

  3. Comparative evaluation between 20% EDTA-S & Ornidazole gel as root biomodification agent ASEM study

    Directory of Open Access Journals (Sweden)

    Prashant V Khairnar, NilkanthMhaske, NeelimaRajhans, NikeshN Moolya, Sudeep HM

    2014-04-01

    Full Text Available Background: It should be well understood that the root surface receptiveness to clot formation & initial periodontal wound healing decides the nature of the connective tissue attachments. This study was carried out to assess the initial wound healing events after the application of 20% EDTA-S & Ornidazole gel and assess the formation of fibrin network following blood. Material& Method: Thirty multi-rooted teeth indicated for extraction due to periodontal disease were selected & divided into group A (20%EDTA-S, group B (Ornidazole gel (1% W/V, group C (7.4pH phosphate buffer saline, group D (20%EDTA-S+ Blood, group E (Ornidazole gel+ Blood, group F (7.4pH phosphate buffer saline+ Blood. Following root planning, the root surface was cut using diamond disc under copious irrigation. Samples from each group were subjected for root conditioning agent application by passive method. Specimens were then subjected to scanning electron microscopic study. Smear layers removal were analysed by Sampaia et al index. Results: 20%EDTA-S removed the smear layer better than ornidazole gel. Fibrin network formation was seen with specimen treated with 20% EDTA-S + Blood. Conclusion: Use of 20% EDTA-S as root conditioning agent has a beneficial effect on initial wound healing events, which are important for periodontal regenerative therapies.

  4. A new method for concentration analysis of bacterial endotoxins in perfluorocarbon

    Science.gov (United States)

    Chen, Dan-Dan; Feng, Xiao-Ming; Wang, Chun-Ren; Huang, Qing-Quan; Yang, Zhao-Peng; Meng, Qing-Yuan

    2014-12-01

    This communication demonstrates the feasibility of the gel-clot method for the analysis of bacterial endotoxins in water extracts of perfluorocarbon which is a water insoluble liquid medical device. Perfluorocarbon (10 mL) was shaken with 10mL water for 15 min at 2000 r/min and the endotoxin present was extracted to the aqueous phase without interference inhibition/enhancement of the product and the recovery of endotoxin added to perfluorocarbon was determined. A validation study confirmed that endotoxins presented in perfluorocarbon pass over into the aqueous phase at concentrations of 20, 10 and 5 EU/mL with recoveries from 86.8% to 96.8%. Therefore, the gel-clot test is suitable for detecting bacterial endotoxins in perfluorocarbon which is a water insoluble medical device.

  5. LumeNEXT: A Practical Method to Pattern Luminal Structures in ECM Gels.

    Science.gov (United States)

    Jiménez-Torres, José A; Peery, Stephen L; Sung, Kyung E; Beebe, David J

    2016-01-21

    In vitro biomimetic modeling of physio-logical structures bridges the gap between 2D in vitro culture and animal models. Lumens (tubular structures) are ubiquitous in vivo, being present in blood vessels, mammary ducts, and the lymphatic system. A method 'LumeNEXT' is presented here that allows the fabrication of 3D embedded lumens where size, structure, distance, and configuration can be controlled using standard poly-dimethylsiloxane micromolding methods.

  6. Efficacy and tolerance of papain gel with conventional drilling method: a clinico-microbiological study.

    Science.gov (United States)

    Goyal, P A; Kumari, R; Kannan, V P; Madhu, S

    2015-01-01

    Conventional methods of caries removal are commonly associated with pain, fear and discomfort. Chemomechanical methods were introduced to instill a positive dental attitude. Agents like GK-101, Caridex, Carisolv did not prove effective alternatives owing to their high cost, need of special instruments and taste of chlorine. A new chemomechanical agent, Papacarie®, has been introduced to overcome these deficiencies. This study was aimed to compare the effectiveness and tolerance of Papacárie® with the conventional method. 25 children with at least two primary teeth with broad cavitated occlusal or cervical lesion were selected. One carious tooth from each patient was randomly treated with each of Papacarie® and conventional drilling method, one after the other. Time taken for caries excavation, child's pain perception, change in anxiety levels, microbial flora and child's preference of treatment were recorded separately for both the methods. Although the mean time taken for caries removal by the Papacarie® method was slightly longer (P≯0.05) but it led to reduction in pain and anxiety (premoval.

  7. Comparison of three methods of DNA extraction in endocervical specimens for Chlamydia trachomatis infection by spectrophotometry, agarose gel, and PCR.

    Science.gov (United States)

    Jenab, Anahita; Roghanian, Rasoul; Golbang, Naser; Golbang, Pouran; Chamani-Tabriz, Leili

    2010-06-01

    Chlamydia trachomatis is the major cause of sexually transmitted disease in the world. The aim of this study was to determine the best method of DNA extraction for detecting C. trachomatis by polymerase chain reaction (PCR) in sexually active women (n = 80) attending Shahid Beheshti Hospital in Isfahan, Iran. Endocervical swabs were collected from 80 women, 22 of whom were asymptomatic and 58 symptomatic. Three different DNA extraction methods were used in this study (phenol-chlorophorm, proteinase K, and boiling). DNA yield was evaluated by spectrophotometry, agarose gel, and PCR. The internal control was assayed by beta-globin primers (PCO4, GH20). The DNA cryptic plasmid was selected as the target for C. trachomatis and samples were examined by PCR using specific KL1 and KL2 primers. It was shown that DNA extraction by boiling was the most sensitive with the highest yield of DNA. Of the 80 samples, 17 (21.25%) showed positivity for C. trachomatis by PCR. The highest rate of C. trachomatis infection was found in the group aged between 35 and 45 years old and those who used withdrawal or an intrauterine device as methods of contraception. It was demonstrated that DNA extraction by boiling was the least expensive and a very rapid method that gave the highest DNA yield. The infection rate in the sexually active women, including symptomatic and asymptomatic, was 21.25%, with a presumably high prevalence compared with other studies done in this field.

  8. Investigations on electrical conductivity and dielectric properties of Na doped ZnO synthesized from sol gel method

    Energy Technology Data Exchange (ETDEWEB)

    Tabib, Asma; Sdiri, Nasr [Laboratoire de Physico-Chimie des Matériaux Minéraux et leurs Applications, Centre National de Recherches en Sciences des Matériaux, B.P. 95 Hammam-Lif, 2050 (Tunisia); Elhouichet, Habib, E-mail: habib.elhouichet@fst.rnu.tn [Laboratoire de Physico-Chimie des Matériaux Minéraux et leurs Applications, Centre National de Recherches en Sciences des Matériaux, B.P. 95 Hammam-Lif, 2050 (Tunisia); Département de Physique, Faculté des Sciences de Tunis, University Tunis El Manar, Tunis 2092 (Tunisia); Férid, Mokhtar [Laboratoire de Physico-Chimie des Matériaux Minéraux et leurs Applications, Centre National de Recherches en Sciences des Matériaux, B.P. 95 Hammam-Lif, 2050 (Tunisia)

    2015-02-15

    Highlights: • ZnO nanoparticles doped with Na were prepared from sol-gel method. • Electric conductivity and dielectric properties were investigated. • The ZnO conductivity is estimated to be of p-type for critical Na doping of 1.5% at. - Abstract: Na doped ZnO nanoparticles (NPs) were elaborated by sol gel technique. The X-ray diffraction patterns show that the peaks are indexed to the hexagonal structure without any trace of an extra phase. Electric and dielectric properties were investigated using complex impedance spectroscopy. The impedance spectra were analyzed in terms of equivalent circuits involving resistors, capacitors and constant phase elements (CPE). The contribution of grain boundary resistance to the total resistance of the system is remarkable. The AC conductivity increases with temperature following the Arrhenius law, with single apparent activation energy for conduction process. The frequency dependence of the electric conductivity follows a simple power law behavior, in according to relation σ{sub AC}(ω) = σ(0) + A ω{sup s}, where s is smaller than 1. The analysis of dc conductivity indicates that the conduction is ionic in nature. The study of its variation, at fixed temperature, with Na content shows sharp decrease which is explained by the formation of Na{sub Zn} acceptor. It was found that the dc conductivity reaches its minimum value for critical Na concentration of 1.5% at which the conductivity is estimated to be of p-type. Impedance and modulus study reveals the temperature dependent non-Debye type relaxation phenomenon. Dielectric studies revealed a promising dielectric properties (relatively high ε′ at low frequencies and low loss at high frequencies). In the low-frequency region, the values of M′ tends to zero suggesting negligible or absent electrode polarization phenomenon. The frequency dependent maxima in the imaginary modulus are found to obey to Arrhenius law.

  9. Gel microbead cultivation with a subenrichment procedure can yield better bacterial cultivability from a seawater sample than standard plating method

    Science.gov (United States)

    Ji, Shiqi; Zhao, Rui; Yin, Qi; Zhao, Yuan; Liu, Chenguang; Xiao, Tian; Zhang, Xiaohua

    2012-03-01

    A gel microbead (GMD) cultivation method was employed to cultivate microorganisms from an amphioxus breeding zone in Qingdao, P. R. China. The culture results were compared with those by standard plating method. In the GMD-based method, the microcolony-forming GMDs were sorted by fluorescence-activated cell sorting (FACS). To further get pure cultures, a subsequent enrichment culture and a streaking purification procedure were conducted on marine R2A medium. Eighty bacterial strains isolated by the GMD-based method were randomly selected for sequencing. These isolates belonged to Alphaproteobacteria (33%), Gammaproteobacteria (44%), Bacteroidetes (11%), Actinobacteria (5%), Firmicutes (5%), Epsilonproteobacteria (1%), and Verrucomicrobia (1%), the last two groups being usually difficult to culture. The 16S rRNA gene sequences revealed a diverse community with 91.1%-100% of the bacterial rRNAs similarities. Thirteen strains were sharing 16S rRNA gene sequence which was less than 97% similar to any other rRNA genes currently deposited in TYP16S database. Seventy isolates derived from the standard plating method fell into 4 different taxonomic groups: Alphaproteobacteria (9%), Gammaproteobacteria (81%), Bacteroidetes (7%) and Firmicutes (3%) with a 16S rRNA gene sequence similarities between 95.8%-100%, in which only 3 strains were sharing 16S rRNA gene sequence of less than 97%. The results indicated that the GMD-based method with subenrichment culture yielded more taxonomic groups and more novel microbial strains, including members of previously rarely cultured groups, when compared with the standard plating method, and that this method markedly improved the bacterial cultivability.

  10. Synthesis of nanocrystalline γ-Al2O3 by sol-gel and precipitation methods for methanol dehydration to dimethyl ether

    Institute of Scientific and Technical Information of China (English)

    Zahra Hosseini; Majid Taghizadeh; Fereydoon Yaripour

    2011-01-01

    The capability of sol-gel and conventional precipitation techniques for the synthesis of nanocrystalline γ-alumina was investigated.These catalysts were used for vapor-phase dehydration of methanol to dimethyl ether in a fixed-bed reactor under the same operating conditions (T= 300℃,P=1 bar,LHSV = 2.8,11.7,26.1 h-1)and characterized by means of N2 adsorption-desorption,NH3-TPD,XRD,TGA and SEM techniques.According to the experimental results,the catalysts prepared using sol-gel method in non-aqueous medium showed better performance compared with those prepared by other methods.

  11. An optical approach for non-invasive blood clot testing

    Science.gov (United States)

    Kalchenko, Vyacheslav; Brill, Alexander; Fine, Ilya; Harmelin, Alon

    2007-02-01

    Physiological blood coagulation is an essential biological process. Current tests for plasma coagulation (clotting) need to be performed ex vivo and require fresh blood sampling for every test. A recently published work describes a new, noninvasive, in vivo approach to assess blood coagulation status during mechanical occlusion1. For this purpose, we have tested this approach and applied a controlled laser beam to blood micro-vessels of the mouse ear during mechanical occlusion. Standard setup for intravital transillumination videomicroscopy and laser based imaging techniques were used for monitoring the blood clotting process. Temporal mechanical occlusion of blood vessels in the observed area was applied to ensure blood flow cessation. Subsequently, laser irradiation was used to induce vascular micro-injury. Changes in the vessel wall, as well as in the pattern of blood flow, predispose the area to vascular thrombosis, according to the paradigm of Virchow's triad. In our experiments, two elements of Virchow's triad were used to induce the process of clotting in vivo, and to assess it optically. We identified several parameters that can serve as markers of the blood clotting process in vivo. These include changes in light absorption in the area of illumination, as well as changes in the pattern of the red blood cells' micro-movement in the vessels where blood flow is completely arrested. Thus, our results indicate that blood coagulation status can be characterized by non-invasive, in vivo methodologies.

  12. 21 CFR 173.150 - Milk-clotting enzymes, microbial.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Milk-clotting enzymes, microbial. 173.150 Section 173.150 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD...

  13. A simple method for purification of rat alpha-fetoprotein by affi-gel blue chromatography and disc electrophoresis

    Directory of Open Access Journals (Sweden)

    Miyazaki,Masahiro

    1981-12-01

    Full Text Available Alpha-getoprotein (AFP was purified from fetal rat serum by a combined technique of affinity chromatography with Affi-Gel Blue and disc electrophoresis followed by extraction of AFP from the gel. The purified AFP was immunologically identical with the original AFP in fetal rat serum.

  14. A simple method for purification of rat alpha-fetoprotein by affi-gel blue chromatography and disc electrophoresis

    OpenAIRE

    Miyazaki, Masahiro; Matsuura,Kazuhiko; Wahid, Syarifuddin; Izumi, Masaki; Taketa, Kazuhisa; Sato,Jiro

    1981-01-01

    Alpha-getoprotein (AFP) was purified from fetal rat serum by a combined technique of affinity chromatography with Affi-Gel Blue and disc electrophoresis followed by extraction of AFP from the gel. The purified AFP was immunologically identical with the original AFP in fetal rat serum.

  15. Denaturing and non-denaturing gel electrophoresis as methods for the detection ofjunctional diversity in rearranged T cell receptor sequences

    NARCIS (Netherlands)

    Offermans, M.T.C.; Sonneveld, R.D.; Bakker, E.; Deutz-Terlouw, P.P.; Geus, B. de; Rozing, J.

    1995-01-01

    Two nucleic acid gel electrophoresis techniques were tested as a possible tool for analyzing junctional diversity in rearranged T cell receptor (TcR) sequences in order to define the extent of T cell heterogeneity. For this purpose denaturing gradient gel electrophoresis (DGGE) as well as

  16. Modified Sol-Gel Technique as a Cost-Effective Method of Ultradispersed Metal Oxide Powders Production

    Science.gov (United States)

    Vokhmintcev, K. V.; Konstantinov, O. V.; Belousov, V. V.

    2013-05-01

    A modified sol-gel technique was developed for fabrication of ultradispersed metal oxides powders of Bi2O3, CeO2, Cr2O3, Y2O3, ZnO2 and ZrO2. Hexamethylenetetramine, monoethanolamine and acetylacetone were used for the sol formation and gel stabilization.

  17. Effect of vanadium on the obtaining of the titanium dioxide by Sol-Gel Method; Efeito do vanadio na obtencao de dioxido de titanio pelo Metodo Sol-Gel

    Energy Technology Data Exchange (ETDEWEB)

    Granado, S.R.; Silva, D.W.; Lopes, S.A.; Cavalheiro, A.A., E-mail: sandrogranado02@gmail.com [Universidade Estadual de Mato Grosso do Sul (CPTREN/UEMS), Navirai, MS (Brazil). Centro de Pesquisas Tecnologicas em Recursos Naturais

    2011-07-01

    The obtaining of transition metal modified titanium dioxide (TiO{sub 2}) can be a promising path to promote changes in crystal structure of anatase phase in order to displace the band gap toward frequencies near to visible region. The insertion of the heterovalent ions such as vanadium can be shift the titanium coordination number in the anatase matrix, leading to important changes in the photonic characteristics of the material. In Sol-Gel method, the presence of the non alkoxide precursors can affects the stability of the solution and the gelifying process, with consequences on the characteristics of the material. In this work, it was investigated the effect of 5mol% of vanadium by thermal analysis of the dried gel and XRD and adsorption isotherm in the samples obtained at different temperatures. The decomposition steps of the precursor were associated to phase formation in the material, leading to conclusion that the presence of vanadium affects the stability of anatase phase. (author)

  18. Plasma carboxypeptidase U (CPU, CPB2, TAFIa) generation during in vitro clot lysis and its interplay between coagulation and fibrinolysis.

    Science.gov (United States)

    Leenaerts, Dorien; Aernouts, Jef; Van Der Veken, Pieter; Sim, Yani; Lambeir, Anne-Marie; Hendriks, Dirk

    2017-07-26

    Carboxypeptidase U (CPU, CPB2, TAFIa) is a basic carboxypeptidase that is able to attenuate fibrinolysis. The inactive precursor procarboxypeptidase U is converted to its active form by thrombin, the thrombin-thrombomodulin complex or plasmin. The aim of this study was to investigate and characterise the time course of CPU generation in healthy individuals. In plasma of 29 healthy volunteers, CPU generation was monitored during in vitro clot lysis. CPU activity was measured by means of an enzymatic assay that uses the specific substrate Bz-o-cyano-Phe-Arg. An algorithm was written to plot the CPU generation curve and calculate the parameters that define it. In all individuals, CPU generation was biphasic. Marked inter-individual differences were present and a reference range was determined. The endogenous CPU generation potential is the composite effect of multiple factors. With respect to the first CPU activity peak characteristics, we found correlations with baseline proCPU concentration, proCPU Thr325Ile polymorphism, time to clot initiation and the clot lysis time. The second CPU peak related with baseline proCPU levels and with the maximum turbidity of the clot lysis profile. In conclusion, our method offers a technique to determine the endogenous CPU generation potential of an individual. The parameters obtained by the method quantitatively describe the different mechanisms that influence CPU generation during the complex interplay between coagulation and fibrinolysis, which are in line with the threshold hypothesis.

  19. A simple, quantitative method using alginate gel to determine rat colonic tumor volume in vivo.

    Science.gov (United States)

    Irving, Amy A; Young, Lindsay B; Pleiman, Jennifer K; Konrath, Michael J; Marzella, Blake; Nonte, Michael; Cacciatore, Justin; Ford, Madeline R; Clipson, Linda; Amos-Landgraf, James M; Dove, William F

    2014-04-01

    Many studies of the response of colonic tumors to therapeutics use tumor multiplicity as the endpoint to determine the effectiveness of the agent. These studies can be greatly enhanced by accurate measurements of tumor volume. Here we present a quantitative method to easily and accurately determine colonic tumor volume. This approach uses a biocompatible alginate to create a negative mold of a tumor-bearing colon; this mold is then used to make positive casts of dental stone that replicate the shape of each original tumor. The weight of the dental stone cast correlates highly with the weight of the dissected tumors. After refinement of the technique, overall error in tumor volume was 16.9% ± 7.9% and includes error from both the alginate and dental stone procedures. Because this technique is limited to molding of tumors in the colon, we utilized the Apc(Pirc/+) rat, which has a propensity for developing colonic tumors that reflect the location of the majority of human intestinal tumors. We have successfully used the described method to determine tumor volumes ranging from 4 to 196 mm³. Alginate molding combined with dental stone casting is a facile method for determining tumor volume in vivo without costly equipment or knowledge of analytic software. This broadly accessible method creates the opportunity to objectively study colonic tumors over time in living animals in conjunction with other experiments and without transferring animals from the facility where they are maintained.

  20. Method of fabrication of microarray of gel-immobilized compounds on a chip by copolymerization

    Science.gov (United States)

    Mirzabekov, Andrei; Timofeev, Edouard; Vasiliskov, Vadim

    2003-12-02

    A method for making polymerized molecules is provided whereby a solution containing monomer is contacted to a solid substrate so as to form discrete accumulations of the monomer on the substrate; and the accumulations are contacted with a polymerizing agent, wherein the agent is dispersed in a vehicle which prevents cross contamination of the accumulations.

  1. Effectiveness of silica based sol-gel microencapsulation method for odorants and flavors leading to sustainable environment.

    Science.gov (United States)

    Ashraf, Muhammad Aqeel; Khan, Aysha Masood; Ahmad, Mushtaq; Sarfraz, Maliha

    2015-01-01

    Microencapsulation has become a hot topic in chemical research. Technology mainly used for control release and protection purposes. The sol-gel micro encapsulation approach for fragrance and aroma in porous silica-based materials leads to sustainable odorant and flavored materials with novel and unique beneficial properties. Sol-gel encapsulation of silica based micro particles considered economically cheap as capital investment in manufacturing is very low and environmentally friendly. Amorphous sol-gel SiO2 is non-toxic and safe, whereas the sol-gel entrapment of delicate chemicals in its inner pores results in pronounced chemical and physical stabilization of the entrapped active agents, thereby broadening the practical utilization of chemically unstable essential oils (EOs). Reviewing progress in the fabrication of diverse odorant and flavored sol-gels, shows us how different synthetic strategies are appropriate for practical application with important health and environmental benefits.

  2. EFFECTS OF GELATION RETARDATION ON THERMAL RESPONSE BEHAVIOR OF PNIAPM GELS: A METHOD TO IMPROVE THEIR DESWELLING KINETICS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    P(N-isopropylacrylamide) (PNIPAM) prepared by reversible addition fragmentation chain transfer (RAFT) polymerization exhibited gelation retardation. The intermediate before gelation was characterized and indicated the presence of branched or hyperbranched chains. The swelling behavior was investigated, and the gel by RAFT polymerization (RAFT gel) showed accelerated shrinking kinetics and higher swelling ratio comparing with conventional gels (CG). The study was extended to gels prepared by using 2-hydroxy-1-ethanethiol as chain transfer agent and by using low concentration solutions.The two systems also exhibited retardation effects and improved deswelling kinetics. The different swelling behaviors of these gels and CG could be attributed to the presence of dangling chains caused by gelation retardation.

  3. Effectiveness of silica based Sol-gel microencapsulation Method for odorants and flavours leading to sustainable Environment

    Directory of Open Access Journals (Sweden)

    Muhammad Aqeel eAshraf

    2015-08-01

    Full Text Available Microencapsulation has become a hot topic in chemical research. Technology mainly used for control release and protection purposes. The sol–gel micro encapsulation approach for fragrance and aroma in porous silica-based materials leads to sustainable odorant and flavored materials with novel and unique beneficial properties. Sol-gel encapsulation of silica based micro particles considered economically cheap as capital investment in manufacturing is very low and environmentally friendly. Amorphous sol–gel SiO2 is non-toxic and safe, whereas the sol–gel entrapment of delicate chemicals in its inner pores results in pronounced chemical and physical stabilization of the entrapped actives, thereby broadening the practical utilization of chemically unstable essential oils. Reviewing progress in the fabrication of diverse odorant and flavoured sol-gels, shows us how different synthetic strategies are appropriate for practical application with important health and environmental benefits.

  4. A French National Survey on Clotting Disorders in Mastocytosis

    Science.gov (United States)

    Carvalhosa, Ana B.; Aouba, Achille; Damaj, Gandhi; Canioni, Danielle; Brouzes, Chantal; Gyan, Emmanuel; Durupt, Stéphane; Durieu, Isabelle; Cathebras, Pascal; Costédoat-Chalumeau, Nathalie; Launay, David; Pilmis, Benoit; Barete, Stephane; Frenzel, Laurent; Lortholary, Olivier; Hermine, Olivier; Hermans, Cedric; Chandesris, Marie-Olivia

    2015-01-01

    Abstract Mastocytosis is characterized by a clonal mast cell proliferation with organ infiltration and uncontrolled degranulation. Although not characteristic and poorly explained, some patients develop clotting abnormalities. We retrospectively identified patients with established diagnosis of mastocytosis and related clotting abnormalities (clinical and/or biological) using the national French Reference Centre for Mastocytosis database. From our cohort of 14 adult patients with clotting abnormalities (median age 46 years [range 26–75]), 4 had a presentation suggestive of a primary hemostasis disorder alone (by their symptoms and/or abnormal clotting tests [PFA, von Willebrand's disease [vWD] screening]) and 10 had a laboratory impairment of secondary hemostasis. Among these, 7 had bleeds characteristic of a coagulation cascade disorder (severe/life-threatening in 5 and mild in 2 patients). Clotting abnormalities were of variable severity, typically related to intense crisis of degranulation, such as anaphylactic reactions, and/or to severe organ infiltration by mast cells. Importantly, classical hemostatic management with platelet transfusion, fresh frozen plasma, or vitamin K infusions was unsuccessful, as opposed to the use of agents inhibiting mast cell activity, particularly steroids. This illustrates the crucial role of mast cell mediators such as tryptase and heparin, which interfere both with primary (mainly via inhibition of von Willebrand factor) and secondary hemostasis. There was interestingly an unusually high number of aggressive mastocytosis (particularly mast cell leukemia) and increased mortality in the group with secondary hemostasis disorders (n = 5, 36% of the whole cohort). Mast cell degranulation and/or high tumoral burden induce both specific biologic antiaggregant and anticoagulant states with a wide clinical spectrum ranging from asymptomatic to life-threatening bleeds. Hemostatic control is achieved by mast cell inhibitors such as

  5. In2O3 Ultrafine Powder Synthesis by Sol-Gel Method

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The precursor of ultrafine In2O3 powder was prepared by the hydrolysis, peptization and gelation of InC13 @4H2O used as raw material.After calcination, ultrafine In2O3 powder was obtained. The particles were characterized by the methods of thermo-gravimetric and differential thermal analysis (TG-DTA), X-ray diffractometry (XRD) and transmission electron microscopy (TEM), respectively.

  6. A comparative study of Ni0.7Zn0.3Fe2O4 obtained by sol-gel auto-combustion and flash combustion methods

    Science.gov (United States)

    Sutka, A.; Lagzdina, S.; Mezinskis, G.; Pludons, A.; Vitina, I.; Timma, L.

    2011-12-01

    In this study, the nickel-zinc ferrites were prepared via two different methods: the sol-gel auto combustion method and the flash combustion method. Obtained reaction products were sintered at different temperatures 900, 1100 and 1300 °C. The structural and microstructural, as well as electric and dielectric properties of different samples were discussed. The synthesis method has a marked effect on crystalline order, grain size and its distribution, electrical resistivity and dielectric properties.

  7. [Comparison of a new and rapid method, Brucella Coombs gel test with the other methods in the serological diagnosis of brucellosis].

    Science.gov (United States)

    İrvem, Arzu; Yücel, Fatma Muhterem; Aksaray, Sabahat; Bor, Emire

    2015-04-01

    Diagnosis of brucellosis basically depends on blood and/or bone marrow culture and demonstration of high titer specific antibody or seroconversion in serum. In routine serological diagnosis of the disease, after screening with Rose Bengal test, the positive samples are studied with standart tube agglutination (STA) test with serial dilutions. However false negative results can be seen in STA test due to the existence of blocking antibodies, this test should be verified with Coombs anti-Brucella (CAB) or immunocapture agglutination (ICA) tests. In recent years Brucella Coombs gel test (ODAK Brucella Coombs Gel Test, Toprak Medikal, Turkey) developed in our country, was available as a new and rapid agglutination based method. The test is performed in vials that contain Coombs antibodies within gel matrix and results are evaluated visually within two hours.The aim of this study was to compare the efficacy of Brucella Coombs gel test (BCGT) with STA, CAB and ICA methods in serological diagnosis of brucellosis. A total of 100 serum samples with suspected brucellosis sent to our laboratory between January 2012-August 2013 in which 31 high positive (≥ 1/160), 23 low positive (≤ 1/80) and 46 negative samples diagnosed with CAB test (Seromed, Turkey) were included in the study. All the samples were studied using titrations with STA (Seromed, Turkey), ICA (Vircell, Spain) and BCGT (Islab, Turkey) methods. With STA, CAB and BCGT tests ≥ 1/160, with ICA test ≥ 1/320 were accepted as positive titers. The correlation between the tests were evaluated with Cohen's kappa (κ) analysis. In our study, seven of the samples yielded positive results with STA, 30 with ICA, and 32 with BCGT. The number of the sera which yielded positive results with all three methods was 28. Two samples positive with CAB and BCGT resulted low titer/negative with ICA, one sample positive with ICA and BCGT resulted low titer/negative with CAB, and one low titer/negative sample with CAB and BCGT

  8. Capture of lipopolysaccharide (endotoxin by the blood clot: a comparative study.

    Directory of Open Access Journals (Sweden)

    Margaret T Armstrong

    Full Text Available In vertebrates and arthropods, blood clotting involves the establishment of a plug of aggregated thrombocytes (the cellular clot and an extracellular fibrillar clot formed by the polymerization of the structural protein of the clot, which is fibrin in mammals, plasma lipoprotein in crustaceans, and coagulin in the horseshoe crab, Limulus polyphemus. Both elements of the clot function to staunch bleeding. Additionally, the extracellular clot functions as an agent of the innate immune system by providing a passive anti-microbial barrier and microbial entrapment device, which functions directly at the site of wounds to the integument. Here we show that, in addition to these passive functions in immunity, the plasma lipoprotein clot of lobster, the coagulin clot of Limulus, and both the platelet thrombus and the fibrin clot of mammals (human, mouse operate to capture lipopolysaccharide (LPS, endotoxin. The lipid A core of LPS is the principal agent of gram-negative septicemia, which is responsible for more than 100,000 human deaths annually in the United States and is similarly toxic to arthropods. Quantification using the Limulus Amebocyte Lysate (LAL test shows that clots capture significant quantities of LPS and fluorescent-labeled LPS can be seen by microscopy to decorate the clot fibrils. Thrombi generated in the living mouse accumulate LPS in vivo. It is suggested that capture of LPS released from gram-negative bacteria entrapped by the blood clot operates to protect against the disease that might be caused by its systemic dispersal.

  9. Activated protein C accelerates clot lysis by virtue of its coagulant activity

    NARCIS (Netherlands)

    Fouw, N.J. de; Tilburg, N.H. van; Haverkate, F.; Bertina, R.M.

    1993-01-01

    The effect of human activated protein C (APC) on t-PA dependent fibrinolysis was studied in vitro using plasma (and whole blood) clot lysis techniques. Clot lysis was monitored by measuring the release of soluble 125I-labelled fibrin degradation products from the clot over time. It was demonstrated

  10. (90)Y microspheres prepared by sol-gel method, promising medical material for radioembolization of liver malignancies.

    Science.gov (United States)

    Łada, Wiesława; Iller, Edward; Wawszczak, Danuta; Konior, Marcin; Dziel, Tomasz

    2016-10-01

    A new technology for the production of radiopharmaceutical (90)Y microspheres in the form of spherical yttrium oxide grains obtained by sol-gel method has been described. The authors present and discuss the results of investigations performed in the development of new production technology of yttrium microspheres and determination of their physic-chemical properties. The final product has the structure of spherical yttrium oxide grains with a diameter 25-100μm, is stable and free from contaminants. Irradiation of 20mg samples of grains with diameter of 20-50μm in the thermal neutron flux of 1.7×10(14)cm(-2)s(-1) at the core of MARIA research nuclear reactor allowed to obtain microspheres labelled with the (90)Y isotope on the way of the nuclear reaction (89)Y(n, ɤ)(90)Y. Specific activity of irradiated microspheres has been determined by application of absolute triple to double coincidence ratio method (TDCR) and has been evaluated at 190MBq/mg Y. (90)Y microspheres prepared by the proposed technique can be regarded as a promising medical material for radioembolization of liver malignancies.

  11. Optical characterization of pure and Al-doped ZnO prepared by sol-gel method

    Science.gov (United States)

    Belka, Radosław; Keczkowska, Justyna; Kasińska, Justyna

    2016-09-01

    In this paper the preparation process and optical characterization of pure and Al3+ doped zinc oxide (Al:ZnO) coatings will be presented. ZnO based materials have been studied extensively due to their potential applications in optoelectronic devices as conductive gas sensors, transparent conductive, electrodes, solar cell windows, varistors, UVfilters or photovoltaic cells. It is II-VI semiconductor with wide-band gap of 3.37 eV and large exciton binding energy of 60meV. It is possible to improve the conductivity of ZnO coating by intentionally doping ZnO with aluminium ions during preparation process. Such transparent and conducting thin films, known as AZO (Aluminium Zinc Oxide) films, are very good candidate for application as transparent conducting materials in many optoelectronic devices. The well-known sol-gel method is used for preparation of solution, coated on glass substrates by dip coating process. Prepared samples were investigated by Raman and UV-VIS spectroscopy. Transmittance as well as specular and diffuse reflectance spectroscopy methods were used for studies of optical parameters. We found that Al admixture influences on optical bandgap of ZnO.

  12. PPHASE AND MORPHOLOGY FORMATION OF Na DOPED PMN THIN FILMS PREPARED BY MODIFIED SOL-GEL METHOD

    Directory of Open Access Journals (Sweden)

    HELENA BRUNCKOVÁ

    2013-03-01

    Full Text Available Na doped lead magnesium niobate Pb(Mg1/3Nb2/3O3 (Na-PMN thin films of 100 nm thickness were prepared by modified sol-gel route with niobium precursor. Na-PMN films were deposited from sol derived using tartaric acid modified polymerizable complex method by mixing of Nb-tartarate (Pechini complex with Na, Pb and Mg acetates at 80°C with molar ratio of Na : Pb : Mg : Nb = 1/2 : 1 :1/3 : 2/3 on Pt/Al2O3 substrates by spin-coating method. In Na doped PMN film the perovskite Pb(Mg1/3Nb2/3O3 phase (65 vol. % and a small amount of pyrochlore Na2Nb8O21 phase were revealed after sintering at 650°C. In the microstructure of 2-layered Na-PMN/Pt/Al2O3 thin film, with ~9.5 nm of roughness, the bimodal particle distribution was observed with small spherical particles of pyrochlore phase and larger sponge-like particles of the perovskite phase. The smallest visible spherical particles (~30 nm and mutually interconected particles (~125 nm were found in TEM and AFM micrographs.

  13. Photophysical properties of organic fluorescent probes on nanosized TIO 2/SIO 2 systems prepared by the sol-gel method

    Science.gov (United States)

    Eremenko, A.; Smirnova, N.; Rusina, O.; Linnik, O.; Eremenko, T. B.; Spanhel, L.; Rechthaler, K.

    2000-10-01

    Highly transparent TiO 2 and TiO 2/SiO 2 films prepared using the sol-gel technique have been studied by means of fluorescence probes method. Electronic interactions between adsorbed species—pyrene and donor-acceptor substituted push-pull stilbene—and Ti-doped silica matrices have been studied by the methods of steady-state and momentary spectrofluorimetry. Organic molecules are strongly adsorbed on the TiO 2 and Ti/Si surfaces. Increasing the Ti content within Ti/Si systems results in a decrease in the intensity of the photoluminescence spectra. These findings indicate that titania oxide species are highly dispersed within silica matrices, probably without aggregating each other, and adsorbed molecules are in direct contact with titanium ions located on the Ti/Si surface. The time scale of these decay processes is tens of nanoseconds. The fluorescence emission quenching can be attributed to the charge injection from the singlet excited state of the molecule to the conduction band of the semiconductor.

  14. Sample Preparation and Staining Methods for Two-Dimensional Polyacrylamide Gel Electrophoresis of Proteins from Animal Tissues

    Directory of Open Access Journals (Sweden)

    Levente Czegledi

    2010-05-01

    Full Text Available Proteomics in animal science as well as in other biological sciences is a significant tool in the post-genomic era. In proteomic studies the presence and relative abundance of expressed proteins of a cell, tissue or biological fluid is studied. Recently, the whole genome of more and more domestic animal species is known, but genes and the transcribed mRNA have no direct effect on biological systems as they are regulated by proteins, which explain the importance of proteomics. The most common tool in proteomic approach is the two-dimensional polyacrylamide gel electrophoresis (2D PAGE, when proteins are separated by their isoelectric point followed by their mass separation as a second dimension. In this study authors used different sample preparation and protein staining methods on meat,  liver and blood plasma and carried out 2D PAGE experiments. The most appropriate sample preparation methods are described in this paper. We concluded that depletion of major proteins in plasma is required but not necessary for meat and liver samples.

  15. Electrical properties Sr2FeTiO6 double perovskite material synthesized by sol-gel method

    Science.gov (United States)

    Masta, N.; Triyono, D.; Laysandra, H.

    2017-07-01

    The structure and electrical properties of double perovskite Sr2FeTiO6 have been studied. Sr2FeTiO6 were prepared by sol-gel method results in powder form. Then, the powder was pressed and sintered at 1100 °C to form pellet. The structural features of the systems have been studied using X-Ray Diffraction (XRD), Scanning Electron Micrograph (SEM) and Energy Dispersive Spectroscopy (EDS). Through XRD characterization, the structure of the compound is single phase cubic Perovskite (space group Pm3m) with lattice parameter a = 3,899 Å and crystallite size is 26 nm. The electrical properties of the material, as functions of temperature (293 K - 523 K) and frequency (100 Hz - 1 MHz), were examined by Impedance Spectroscopy method using RLC meter. The imaginary of impedance (Zim) data shows the peaks which indicates the presence of relaxation process in this sample. Activation energy for relaxation process which is evaluated by Arrhenius Law indicates the type of charge carrier is p-type polaron.

  16. Tumour imaging by the detection of fibrin clots in tumour stroma using an anti-fibrin Fab fragment.

    Science.gov (United States)

    Obonai, Toshifumi; Fuchigami, Hirobumi; Furuya, Fumiaki; Kozuka, Naoyuki; Yasunaga, Masahiro; Matsumura, Yasuhiro

    2016-01-01

    The diagnosis of early and aggressive types of cancer is important for providing effective cancer therapy. Cancer-induced fibrin clots exist only within lesions. Previously, we developed a monoclonal antibody (clone 102-10) that recognizes insoluble fibrin but not fibrinogen or soluble fibrin and confirmed that fibrin clots form continuously in various cancers. Here, we describe the development of a Fab fragment probe of clone 102-10 for tumour imaging. The distribution of 102-10 Fab was investigated in genetically engineered mice bearing pancreatic ductal adenocarcinoma (PDAC), and its effect on blood coagulation was examined. Immunohistochemical and ex vivo imaging revealed that 102-10 Fab was distributed selectively in fibrin clots in PDAC tumours 3 h after injection and that it disappeared from the body after 24 h. 102-10 Fab had no influence on blood coagulation or fibrinolysis. Tumour imaging using anti-fibrin Fab may provide a safe and effective method for the diagnosis of invasive cancers by detecting fibrin clots in tumour stroma.

  17. Increased Oxidation as an Additional Mechanism Underlying Reduced Clot Permeability and Impaired Fibrinolysis in Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Anna Lados-Krupa

    2015-01-01

    Full Text Available Aims. We sought to investigate whether enhanced oxidation contributes to unfavorable fibrin clot properties in patients with diabetes. Methods. We assessed plasma fibrin clot permeation (Ks, a measure of the pore size in fibrin networks and clot lysis time induced by recombinant tissue plasminogen activator (CLT in 163 consecutive type 2 diabetic patients (92 men and 71 women aged 65 ± 8.8 years with a mean glycated hemoglobin (HbA1c of 6.8%. We also measured oxidative stress markers, including nitrotyrosine, the soluble form of receptor for advanced glycation end products (sRAGE, 8-iso-prostaglandin F2α (8-iso-PGF2α, oxidized low-density lipoprotein (oxLDL, and advanced glycation end products (AGE. Results. There were inverse correlations between Ks and nitrotyrosine, sRAGE, 8-iso-PGF2α, and oxLDL. CLT showed a positive correlation with oxLDL and nitrotyrosine but not with other oxidation markers. All these associations remained significant for Ks after adjustment for fibrinogen, disease duration, and HbA1c (all P<0.05, while oxLDL was the only independent predictor of CLT. Conclusions. Our study shows that enhanced oxidative stress adversely affects plasma fibrin clot properties in type 2 diabetic patients, regardless of disease duration and glycemia control.

  18. Adenosine diphosphate-decorated chitosan nanoparticles shorten blood clotting times, influencing the structures and varying the mechanical properties of the clots

    Directory of Open Access Journals (Sweden)

    Chung TW

    2014-03-01

    Full Text Available Tze-Wen Chung,1,3 Pei-Yi Lin,2 Shoei-Shen Wang,2 Yen-Fung Chen31Department of Biomedical Engineering, National Yang-Ming University, 2Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan, Republic of China; 3Department of Chemical and Materials Engineering, National Yunlin University of Science and Technology, Yunlin, Taiwan, Republic of ChinaAbstract: Chitosan nanoparticles (NPs decorated with adenosine diphosphate (ADP (ANPs or fibrinogen (FNPs were used to fabricate hemostatic NPs that can shorten blood clotting time and prevent severe local hemorrhage. The structure and mechanical properties of the blood clot induced with ANP (clot/ANP or FNP (clot/FNP were also investigated. The NPs, ANPs, and FNPs, which had particle sizes of 245.1±14.0, 251.0±9.8, and 326.5±14.5 nm and zeta potentials of 24.1±0.5, 20.6±1.9, and 15.3±1.5 mV (n=4, respectively, were fabricated by ionic gelation and then decorated with ADP and fibrinogen. The zeta potentials and Fourier transform infrared (FTIR spectroscopy of the NPs confirmed that their surfaces were successfully coated with ADP and fibrinogen. The scanning electron microscope (SEM micrographs of the structure of the clot induced with "undecorated" chitosan NPs (clot/NP, clot/ANP, and clot/FNP (at 0.05 wt% were different, after citrated bloods had been recalcified by a calcium chloride solution containing NPs, ANPs, or FNPs. This indicated that many NPs adhered on the membrane surfaces of red blood cells, that ANPs induced many platelet aggregates, and that FNPs were incorporated into the fibrin network in the clots. Measurements of the blood clotting times (Tc of blood clot/NPs, clot/ANPs, and clot/FNPs, based on 90% of ultimate frequency shifts measured on a quartz crystal microbalance (QCM, were significantly (P<0.05 (n=4 shorter than that of a clot induced by a phosphate-buffered solution (PBS (clot/PBS (63.6%±3.1%, 48.3%±6.2%, and 63.2%±4.7%, respectively. The ∆F2

  19. Electrical characterization and device characterization of ZnO microring shaped films by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Yakuphanoglu, Fahrettin, E-mail: fyhan@hotmail.co [Firat University, Physics Department, Faculty of Science and Arts, 23119, Elazig (Turkey)

    2010-09-24

    Research highlights: {yields} Zinc oxide microrings formed nanoparticles were prepared by Sol Gel method. {yields} The ZnO film exhibits a polycrystalline grown with a hexagonal wurtzite-type and optical band gap of 3.22 eV. {yields} Au/n-ZnO/n-Si Schottky diode exhibits a rectifying behavior with a higher ideality factor of 2.01 and barrier height of 0.80 eV. - Abstract: Zinc oxide microrings formed nanoparticles were prepared on n-type silicon substrate by sol-gel method. The structure of ZnO film is confirmed by XRD analysis and ZnO film exhibits a polycrystalline grown with a hexagonal wurtzite-type. The optical band gap of the ZnO film deposited on silicon substrate was determined using the reflectance spectra by means of Kubelka-Munk formula and was found to be 3.22 eV. The structural properties of the ZnO film were investigated by atomic force microscopy. The AFM results indicate that the ZnO film is consisted of microrings with nanoparticles. A single phase of ZnO microring with outer diameter is ranging from 2.2 {mu}m to 1.72 {mu}m and inner diameters ranging from 125 nm to 470 nm was obtained. A Schottky diode having Au/n-type ZnO plus n-type silicon structure was fabricated. The current-voltage and impedance spectroscopy properties of the diode have been investigated. The barrier height {phi}{sub b} and ideality factor n values for the diode were found to be 0.80 eV and 2.01, respectively. The series resistance for the diode was calculated from the admittance behavior in accumulation region. The interface state density profile for the diode was obtained. The obtained results indicate that the electric parameters of the diode are affected by structural properties of ZnO film.

  20. Enhancement in dielectric and magnetic properties of Ni–Zn ferrites prepared by sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Nasir, S. [Applied Thermal Physics Laboratory, Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000, Pakistan. (Pakistan); Department of Materials Science and Engineering, Zhejiang University (China); Saleemi, A.S.; Fatima-tuz-Zahra [Applied Thermal Physics Laboratory, Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000, Pakistan. (Pakistan); Anis-ur-Rehman, M., E-mail: marehman@comsats.edu.pk [Applied Thermal Physics Laboratory, Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000, Pakistan. (Pakistan)

    2013-09-25

    Highlights: •Cr-Zn co-doped Ni-Zn ferrites were prepared with a newly reported sol gel method. •Phase purity and a very good control of crystallite and particle size are obtained. •Low eddy current losses are obtained due to low dielectric losses. •Operational frequency of doped Ni-Zn ferrites could be increased up to GHz ranges. -- Abstract: Due to its high permeability, Mn–Zn ferrite is the material of choice for high frequency applications up to a few MHz. At increased operational frequency, Ni–Zn ferrites are more suitable than Mn–Zn ferrites due to their low eddy current losses and low dielectric losses. To combine all these properties and to increase the operational frequency up to GHz, we have prepared Ni{sub 0.5}Zn{sub 0.5}Cr{sub x}Mn{sub 0.5−x}Fe{sub 1.5}O{sub 4} (x = 0.1, 0.2, 0.3, 0.4, 0.5), with a simplified sol gel method. Prepared samples show high saturation magnetization, low coercivity, and low dielectric loss. The dielectric loss in the frequency range 1 MHz to 1.3 GHz remained almost constant as the Cr content was increased in the samples. The crystallite size and lattice parameters of these samples were calculated from X-ray Diffraction (XRD) data analysis. The crystallite size for each sample was calculated using the Scherrer formula considering the most intense peak (3 1 1) and the results were compared with the Scanning Electron Microscope (SEM) images of these samples. Powder X-ray diffraction (XRD) patterns confirmed the single phase spinel structure for these samples. Wayne Kerr Precession Component Analyzer 6440B and Agilent E4991 Impedance Analyzer were used to study the dielectric constant (ε′) and the dielectric loss tangent (tan δ) of these samples as a function of frequency in the frequency range 100 Hz to 1 MHz and 1 MHz to 1.29 GHz respectively. Quantum design PPMS model 6700 was used to study the magnetic properties of these samples.

  1. Electrochemical characterization for lithium vanadium phosphate with different calcination temperatures prepared by the sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yongchao [Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074 (China); Wang, Shengping, E-mail: spwang@cug.edu.cn [Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074 (China); Tao, Du; Dai, Yu [Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074 (China); Yu, Jingxian [ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), School of Chemistry and Physics, The University of Adelaide, Adelaide, SA 5005 (Australia)

    2015-09-15

    Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C (LVP/C) composite materials were synthesized via a sol–gel method with oxalic acid as the chelating agent and polyethylene glycol (PEG) as the supplementary carbon source. The oxalic acid and PEG serve as double carbon sources. This study focused on the effect of different calcination temperatures on the electrochemical properties of Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}. The diffraction peaks for all of the samples are well indexed to monoclinic Li{sub 3}V{sub 2}(PO{sub 4}){sub 3} with a P2{sub 1}/n space group. The TGA data indicate that the residual carbon content of LVP/C-700 is the highest (i.e., 2.31 wt.%), and as the calcination temperature increased, the residual carbon content of the material gradually decreased. SEM and TEM analyses indicated that the LVP particles that were calcined at 700 °C exhibit a uniform particle size distribution and the carbon coating exhibited a complete and orderly moderate thickness. The LVP/C-700 material exhibits the best electrochemical performance in the voltage range of 3.0 to 4.3 V and 0.1 C where the initial discharge capacity can reach 128.98 mAh g{sup −} {sup 1}. Even after 200 cycles, the discharge capacity was 119.31 mAh g{sup −} {sup 1}, and the capacity retention rate was 92.49%. - Highlights: • Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C composite materials have been synthesized via a sol–gel method with double carbon sources. • The different calcination temperatures affect the grain growth and crystallinity of the Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C materials. • The LVP/C-700 material exhibites the largest lithium ion diffusivity and electronic conductivity.

  2. Fabrication and properties of zinc oxide thin film prepared by sol-gel dip coating method

    Directory of Open Access Journals (Sweden)

    Kayani Zohra Nazir

    2015-09-01

    Full Text Available ZnO thin films were deposited on a glass substrate by dip coating technique using a solution of zinc acetate, ethanol and distilled water. Optical constants, such as refractive index n and extinction coefficient k. were determined from transmittance spectrum in the ultraviolet-visible-near infrared (UV-Vis-NIR regions using envelope methods. The films were found to exhibit high transmittance, low absorbance and low reflectance in the visible regions. Absorption coefficient α and the thickness of the film t were calculated from interference of transmittance spectra. The direct optical band gap of the films was in the range of 3.98 to 3.54 eV and the thickness of the films was evaluated in the range of 173 to 323 nm, while the refractive index slightly varied in the range of 1.515 to 1.622 with an increase in withdrawal speed from 100 to 250 mm/s. The crystallographic structure of the films was analyzed with X-ray diffractometer. The films were amorphous in nature.

  3. Synthesis of granular Fe sbnd Al 2O 3 by the sol-gel method

    Science.gov (United States)

    Santos, A.; Ardisson, J. D.; Tambourgi, E. B.; Macedo, W. A. A.

    1998-01-01

    We have investigated the structural and magnetic properties of a granular composite of iron particles dispersed in alumina matrix, obtained starting from an aqueous solution containing Al(NO 3) 3 · 9H 2O and FeSO 4 · 7H 2O. The samples were characterized by X-ray diffraction and fluorescence, Mössbauer spectroscopy (MS) and vibrating sample magnetometry (VSM). Samples with 7.8 wt% Fe were submitted to two different heat treatments with the aim of reducing the iron oxides into metallic iron. Series A was submitted to calcination between 100°C and 1200°C, followed by reduction in ultra pure H 2 at 600°C during 2 h; Series B was submitted to reduction at 600°C or at 1000°C directly after drying at 80°C. As determined by MS, we have obtained a maximum of 24% metallic Fe in series A and of 74% α-Fe in series B, after reduction at 1000°C. By VSM, at 300 K, the maximum coercivity of 819 Oe was obtained for the samples calcinated at 800°C before reduction and an almost constant saturation magnetization of 2 emu/g. In series B, samples with 74% α-Fe presented a coercivity of 370 Oe and a saturation magnetization of 9.0 emu/g. The applied synthesis method seems to be an interesting alternative way to obtain magnetic Fe nanoparticles in a non-magnetic alumina matrix.

  4. Survivability of probiotics encapsulated in alginate gel microbeads using a novel impinging aerosols method.

    Science.gov (United States)

    Sohail, Asma; Turner, Mark S; Coombes, Allan; Bostrom, Thor; Bhandari, Bhesh

    2011-01-31

    Encapsulation of probiotic bacteria in cross-linked alginate beads is of major interest for improving the survivability in harsh acid and bile environment and also in food matrices. Alginate micro beads (10-40 μm) containing the probiotics Lactobacillus rhamnosus GG and Lactobacillus acidophilus NCFM were produced by a novel technique based on dual aerosols of alginate solution and CaCl(2) cross linking solution. Extruded macro beads (approximately 2mm diameter) produced by the conventional method and micro beads produced by novel aerosols technique offered comparable protection to L. rhamnosus in high acid and bile environment. Chitosan coating of micro beads resulted in a significant increase in survival time of L. rhamnosus from 40 to 120 min in acid condition and the reduction in cell numbers was confined to 0.94 log over this time. Alginate macro beads are more effective than micro beads in protecting L. acidophilus against high acid and bile. Chitosan coating of micro beads resulted in similar protection to L. acidophilus in macro beads in acid and extended the survival time from 90 to at least 120 min. Viability of this organism in micro beads was 3.5 log after 120 min. The continuous processing capability and scale-up potential of the dual aerosol technique offers potential for an efficient encapsulation of probiotics in very small alginate micro beads below sensorial detection limits while still being able to confer effective protection in acid and bile environment. Copyright © 2010. Published by Elsevier B.V.

  5. La3+-doped SrBi2Ta2O9 thin films for FRAM synthesized by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    V.V. Sidsky; A.V. Semchenko; A.G. Rybakov; V.V. Kolos; A.S. Turtsevich; A.N. Asadchyi; W. Strek

    2014-01-01

    This paper discusses the possibility of synthesis of SBTL sol-gel films for use as active layers for non-volatile memory (FRAM). La-doped SrBi2Ta2O9 thin films were synthesized by sol-gel method on Pt/TiO2/BPSG/SiO2/Si substrates. The structural features of the surface (AFM), crystallization behavior (XRD) during the heating and ferroelectric properties of synthesized films were discussed. It was shown that an optimum surface structure and a high share of perovskite phase of SBTL-films were compared to SBT-films (Theating=800 ºC). Achieved ferroelectric parameters suggested the possibility of using synthesized SBTL sol-gel films in non-volatile memory devices.

  6. Analytical QbD: development of a native gel electrophoresis method for measurement of monoclonal antibody aggregates.

    Science.gov (United States)

    Pathak, Mili; Dutta, Debayon; Rathore, Anurag

    2014-08-01

    This paper presents a quality by design (QbD) based development of a novel native PAGE (N-PAGE) method as a low-cost analytical tool for analysis of aggregates of monoclonal antibodies. Comparability to the present gold standard of SEC has been established. The motivation is the fact that SEC requires relatively expensive equipment and consumables, thus making N-PAGE relevant to those academicians and other small companies involved in early-stage development of biotherapeutics that do not have access to SEC, especially in developing countries. Furthermore, SEC suffers from certain disadvantages including the possibility of secondary interactions between the stationary phase and analyte resulting in higher elution time and therefore underestimation of the analyte size. The proposed N-PAGE method can also serve as an orthogonal analytical method for aggregate analysis. A QbD-based approach has been used for development and optimization of the protocol. First, initial screening studies were carried out with parameters including the running buffer pH, running buffer molarity, gel buffer pH, loading dye, sample concentration, and running voltage. Next, optimization of operating parameters was performed using principles of design of experiments. The final optimized protocol was compared to the traditional SEC method and the results were found to be comparable. While N-PAGE has been in use for protein analysis for several decades, use of N-PAGE for analysis of mAb aggregates with data comparable to SEC such as the case presented here is novel. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Densitometric HPTLC method for qualitative, quantitative analysis and stability study of Coenzyme Q10 in pharmaceutical formulations utilizing normal and reversed-phase silica gel plates.

    Science.gov (United States)

    Abdel-Kader, Maged Saad; Alam, Prawez; Alqasoumi, Saleh Ibrahim

    2016-03-01

    Two simple, precise and stability-indicating densitometric HPTLC method were developed and validated for qualitative and quantitative analysis of Coenzyme Q10 in pharmaceutical formulations using normal-phase (Method I) and reversed phase (Method II) silica gel TLC plates. Both methods were developed and validated with 10×20 cm glass-backed plates coated with 0.2 mm layers of either silica gel 60 F254 (E-Merck, Germany) using hexane-ethyl acetate (8.5:1.5 v/v) as developing system (Method I) or RP-18 silica gel 60 F254 (E-Merck, Germany) using methanol-acetone (4:6 v/v) as mobile phase (Method II). Both analyses were scanned with a densitometer at 282 nm. Linearity was found in the ranges 50-800 ng/spot (r(2)=0.9989) and 50-800 ng/spot (r(2)=0.9987) for Method I and Method II respectively. Stability of Coenzyme Q10 was explored by the two methods using acid, base, hydrogen peroxide, temperature and different solvents. Due to the efficiency of the method in separating Coenzyme Q10 from other ingredients including its degradation products, it can be applied for quality control, standardization of different pharmaceutical formulations and stability study.

  8. 血小板凝胶的制备方法及其影响因素★%Platelet gel preparation methods and relevant parameters

    Institute of Scientific and Technical Information of China (English)

    温天杨; 王爱红; 许樟荣

    2013-01-01

    BACKGROUND: The preparation methods of platelet gel are various, but there is no uniform standard. OBJECTIVE: To conclude the methods of platelet gel preparation and to explore the relevant parameters. METHODS: The first author searched the PubMed and Wanfang databases for relevant articles published from 1990 to 2011 using the keywords of “platelet gel, classification, parameters” in English and Chinese, respectively. RESULTS AND CONCLUSION: There are two main parameters to classify the different preparation methods, which are the yield and composition of gel and the fibrin network of gel. According to the two main parameters, the preparation methods of platelet gel can be classified into four categories, namely, pure platelet-rich plasma, leukocyte- and platelet-rich plasma, pure platelet-rich fibrin, and leukocyte- and platelet-rich fibrin. According to the preparation process, the preparation methods of PRP gel also can be divided into manual protocol and automatic protocol. There are inadequacies in al the preparation methods.%  背景:血小板凝胶制备方法繁多,分类标准不统一。目的:总结血小板凝胶制备方法,并讨论影响因素。方法:由第一作者检索1990至2011年 PubMed 数据库及万方数据库。英文检索词为“Platelet gel, Classification,Parameters”,中文检索词为“血小板凝胶,分类,影响因素”。结果与结论:依据凝胶产量与成分、凝胶中纤维蛋白结构两个主要影响因素可将血小板凝胶制备方法分为4大类,即纯富血小板血浆凝胶、富白细胞-血小板血浆凝胶、纯富血小板纤维蛋白凝胶和富白细胞-血小板纤维蛋白凝胶;根据制备流程不同,血小板凝胶的每一种制备方法还可以再分为手工制备方法和全自动制备方法,但各种分类方法均存在不足之处。

  9. Effectiveness of silica based sol-gel microencapsulation method for odorants and flavors leading to sustainable environment

    National Research Council Canada - National Science Library

    Ashraf, Muhammad Aqeel; Khan, Aysha Masood; Ahmad, Mushtaq; Sarfraz, Maliha

    2015-01-01

    .... The sol-gel micro encapsulation approach for fragrance and aroma in porous silica-based materials leads to sustainable odorant and flavored materials with novel and unique beneficial properties...

  10. Characterization of dilute magnetic semiconducting transition metal doped ZnO thin films by sol–gel spin coating method

    Energy Technology Data Exchange (ETDEWEB)

    Vijayaprasath, G.; Murugan, R. [Department of Physics, Alagappa University, Karaikudi 630004, Tamil Nadu (India); Ravi, G., E-mail: gravicrc@gmail.com [Department of Physics, Alagappa University, Karaikudi 630004, Tamil Nadu (India); Mahalingam, T. [Department of Electrical and Computer Engineering, Ajou University, Suwon 443-749 (Korea, Republic of); Hayakawa, Y. [Research Institute of Electronics, Shizuoka University, Hamamatsu 432-8011 (Japan)

    2014-09-15

    Graphical abstract: - Highlights: • Diluted magnetic semiconducting TM (Ni, Mn, Co) doped ZnO thin films were fabricated by sol–gel spin coating technique. • The XRD analyses revealed that the TM (Ni, Mn, Co) doped ZnO films have hexagonal wurtzite structure. • Photoluminescence and micro-Raman spectra were interpreted for TM (Ni, Mn, Co) doped ZnO thin films. • SEM morphology studies were made for Zn{sub 0.97} Ni{sub 0.03}O, Zn{sub 0.97} Mn{sub 0.03}O and Zn{sub 0.97} Co{sub 0.03}O thin films. • Room temperature ferromagnetism was observed in TM (Ni, Mn, Co) doped ZnO thin films. - Abstract: Pure and transition metal (TM = Ni, Mn, Co) doped zinc oxide (ZnO) thin films were prepared by sol–gel spin coating method with a concentration of 0.03 mol% of transition metals. X-ray diffraction studies revealed the polycrystalline nature of the films with the presence of hexagonal wurtzite structure. UV transmittance spectra showed that all the films are highly transparent in the visible region and in the case of doped ZnO thin films, d–d transition was observed in the violet region due to the existence of crystalline defects and grain boundaries. The optical band gap of the films decreases with increasing orbital occupation numbers of 3d electrons due to the orbital splitting of magnetic ions. Ultraviolet and near-infrared electronic transitions were observed which reveals a strong relationship with the doping of transition metal into ZnO site. The observed luminescence in the green, violet and red regions strongly depends on the doping elements owing to the different oxygen vacancy, oxygen interstitial, and surface morphology. The surface morphology of thin films was investigated by scanning electron microscope (SEM). The energy dispersive X-ray analysis (EDX) confirmed the stoichiometric composition of the TM doped ZnO thin films. Magnetic measurements at room temperature exhibited well defined ferromagnetic features of the thin films.

  11. Fabrication and characterization of Gd2O2SO4:Tb3+ phosphors by sol-gel method

    Science.gov (United States)

    Aritman, I.; Yildirim, S.; Kisa, A.; Guleryuz, L. F.; Yurddaskal, M.; Dikici, T.; Celik, E.

    2017-02-01

    The objective of the innovative approaches of the scintillation materials to be used in the digital portal imaging systems in the radiotherapy applications is to research the GOS material production that has been activated with the rare earth elements (RE), to produce the scintillation detectors that have a rapid imaging process with a lesser radiation and higher image quality from these materials and to apply the radiographic imaging systems. The GOS: Tb3+ showed high emission peak and high x-ray absorption properties which have been determined for application to mammography and dental radiography. In this study, Gd2O2SO4:Tb3+ phosphors were fabricated by the sol-gel method that is a unique technique and not previously applied. Besides, the structural characterization of GOS: Tb3+ has been investigated. The strongest emission peak located at 549 nm under 312 nm UV light excitation was appeared on the GOS: Tb3+ phosphor particles. The characterization processing optimized by using FTIR, DTA-TG, XRD, XPS, SEM and the luminescence spectroscopy.

  12. Electrical and ferromagnetic properties of Tb-doped indium-tin oxide films fabricated by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Zuo Yalu [Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000 (China); Ge Shihui, E-mail: gesh@lzu.edu.cn [Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000 (China); Yu Zhenhua; Yan Shiming; Zhou Xueyun; Zhang Li [Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000 (China)

    2010-08-01

    The electrical and ferromagnetic properties of (In{sub 0.9-x}Tb{sub x}Sn{sub 0.1}){sub 2}O{sub 3} and (In{sub 0.99-y}Tb{sub 0.01}Sn{sub y}){sub 2}O{sub 3} films fabricated by sol-gel method have been investigated. All the films show room temperature ferromagnetism. The magnetic moment per Tb ion of (In{sub 0.9-x}Tb{sub x}Sn{sub 0.1}){sub 2}O{sub 3} films first increases and then decreases with the increasing Tb content. The variation of conductivity with Tb content is coincident with that of the magnetic moment. Furthermore, the conductivity and magnetic moment variations with Sn content y in (In{sub 0.99-y}Tb{sub 0.01}Sn{sub y}){sub 2}O{sub 3} films also have the similar trend. These results imply that the ferromagnetism may originate from the carrier-mediated mechanism.

  13. Characteristics and Laser Performance of Yb3+-Doped Silica Large Mode Area Fibers Prepared by Sol–Gel Method

    Directory of Open Access Journals (Sweden)

    Shikai Wang

    2013-12-01

    Full Text Available Large-size 0.1 Yb2O3–1.0 Al2O3–98.9 SiO2 (mol% core glass was prepared by the sol–gel method. Its optical properties were evaluated. Both large mode area double cladding fiber (LMA DCF with core diameter of 48 µm and large mode area photonic crystal fiber (LMA PCF with core diameter of 90 µm were prepared from this core glass. Transmission loss at 1200 nm is 0.41 dB/m. Refractive index fluctuation is less than 2 × 10−4. Pumped by 976 nm laser diode LD pigtailed with silica fiber (NA 0.22, the slope efficiency of 54% and “light-to-light” conversion efficiency of 51% were realized in large mode area double cladding fiber, and 81 W laser power with a slope efficiency of 70.8% was achieved in the corresponding large mode area photonic crystal fiber.

  14. Structural and Dielectric Properties of Bismuth Doped Cobalt Nano Ferrites Prepared by Sol-Gel Auto Combustion Method

    Science.gov (United States)

    Routray, Krutika L.; Behera, Dhrubananda

    2017-02-01

    The present study is focused on the preparation of a series of Bismuth doped CoFe2O4 (CFO) nanoparticles and its structural and dielectric properties. The CFO particles having chemical composition CoBixFe2-xO4 (where x = 0.0, 0.1, 0.5) has been synthesized using sol-gel auto combustion method. Phase formation study of the prepared samples is carried out using X -ray diffraction (XRD) technique. It reveals single phase spinel structure having space group Fd3m. The two absorption bands v 1 and v 2 are observed in Fourier transform infrared spectroscopy (FTIR) spectra corresponding to the tetrahedral and octahedral sites, which show mark of spinel structure of the samples. Morphological study is carried out using Field Emission Scanning Electron Microscope (FESEM) and Transmission Electron Microscopy (TEM) which revealed that the particle size obtained is around 40 nm to 120 nm. In addition, phase formation has been confirmed from the analysis of Raman spectra. Different types of conduction mechanism of the charge carriers have been analysed with DC resistivity and AC impedance measurement at room temperature. Results demonstrate the presence of dielectric relaxation, which is found to be of non-Debye type.

  15. Improvement of Mechanical, Thermal and Optical Properties of Barium Mixed Cobalt Tartrate Hydrate Crystals Grown by Gel Method

    Directory of Open Access Journals (Sweden)

    S. Vanaja

    2015-10-01

    Full Text Available In this present work, CTH and BCTH crystals have been prepared by gel technique by using single diffusion method at room temperature. The as grown crystals were characterized by using XRD, FT-IR, UV, TG / DTA and Micro hardness studies. X-ray powder diffraction results analyzed by using suitable software suggest that a CTH and BCTH crystals belong to cubic crystal system. The unit cell volume is observed to increase with increase in the concentration of barium in cobalt tartrate due to the lattice distortion. The band gap and optical properties have analyzed by UV-Visible spectrum. The functional groups and compound formation of the crystals have been studied by FT-IR spectrum. The mechanical properties of the grown crystals were tested by using Vicker’s microhardness studies. The work hardening coefficient (n was determined to be 3.7 for CTH, 5.3 for BCTH (1 : 1 and 6.4 for BCTH (2 : 1 and the stiffness constants for different loads were calculated and reported. Thermal analysis suggests that pure cobalt tartrate starts decomposing at 73.2 °C whereas the barium mixed cobalt tartrate brings about better thermal stability which increases with an increase in barium concentration.

  16. Surface and Texture Properties of Tb-Doped Ceria-Zirconia Solid Solution Prepared by Sol-Gel Method

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The three-way catalysts (TWCs) promoters Ce0.6Zr0.4-xTbxO2-y were prepared by sol-gel method. BET surface areas analysis indicated that an increase of the dopant Tb content from x=0.05 to x=0.15 favors an increase of surface area from 66.8 to 80.4 m2·g-1 compared with the undoped sample Ce0.60Zr0.40O2 65.1 m2·g-1 after calcination at 650 ℃. Transmission electron microscopy (TEM) observation indicated that the doped samples have a higher thermal stability. The XRD and Raman spectra confirmed that the Ce0.6Zr0.4-xTbxO2-y cubic solid solution is formed. XPS analysis revealed that Ce and Tb mainly existed in the form of Ce4+ and Tb3+, and Zr existed in the form of Zr4+ on the surface of the samples. The doped samples were homogenous in composition;the introduction of Tb into the CeO2-ZrO2 promoters resulted in the formation of a solid solution, and the concentration of surface lattice oxygen was increased.

  17. Characterization of Nano-Structured Nickel-Cobalt Ferrites Synthesized By Citrate-Gel Auto Combustion Method

    Directory of Open Access Journals (Sweden)

    Abdul Gaffoor

    2014-04-01

    Full Text Available Nano-ferrites of the composition Ni1-xCoxFe2O4(where x=0.0,0.2,0.4,0.6,0.80 and 1.0 were synthesized at a very low temperature (180°C by Citrate-gel auto combustion method The synthesized powders were sintered at 5000C for four hours in an air and were characterized by X-ray diffraction (XRD which confirmed the formation of cubic spinel structure of ferrites. The crystallite size was in the range of 20nm to 31 nm. Such low nano sized ferrites are desirable for variety of applications like, in magnetic data storage and in etc. Morphological studies by Scanning Electron Microscopy (SEM revealed formation of largely agglomerated, well defined nano particles of the sample. Elemental composition characterizations of the prepared samples were performed by Energy Dispersive Spectroscopy (EDS which shows the presence of Ni, CO, Fe and O without precipitating cations.

  18. Effect of aluminium doping on structural and optical properties of ZnO thin films by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Vijayaprasath, G.; Murugan, R.; Ravi, G., E-mail: raviganesa@rediffmail.com, E-mail: gravicrc@gmail.com [Department of Physics, Alagappa University, Karaikudi – 630003 (India); Hayakawa, Y. [Research Institute of Electronics, Shizuoka University, Hamamatsu 432-8011 (Japan)

    2015-06-24

    We systematically investigated the structural, morphological and optical properties of 0.05 mol % Al doped ZnO (Al:ZnO) thin films deposited on glass substrates by sol-gel spin coating method. The influences of Al doping in ZnO thin films are characterized by Powder X-ray diffraction study. ZnO and Al:ZnO thin films have showed hexagonal wurtzite structure without any secondary phase in c-axis (002) orientation. The SEM images also proved the hexagonal rod like morphologies for both films. All the films exhibited transmittance of 70-80% in the visible range up to 800 nm and cut-off wavelength observed at ∼390 nm corresponding to the fundamental absorption of ZnO. The band gap of the ZnO thin films slightly widened with the Al doping. The photoluminescence properties have been studied for Al: ZnO thin films and the results are presented in detail.

  19. Structural and optical properties of Y, Cu co-doped ZnO nanoparticles by sol-gel method

    Science.gov (United States)

    Anandan, S.; Muthukumaran, S.; Ashokkumar, M.

    2014-10-01

    Zn.96-xY.04CuxO (x = 0, 0.05, 0.10 and 0.15) nanoparticles were successfully synthesized employing simple sol-gel method. Hexagonal wurtzite structure of the synthesized samples was not affected by Cu-doping. CuO phase was induced after Cu = 5% and it was increased by Cu-doping. The change in crystal size was discussed based on compressive stress, lattice volume and bond length. The chemical stoichiometry of Zn, Cu, Y and O was confirmed by energy dispersive X-ray spectra. The increased oxygen percentage from 57.88 (Cu = 5%) to 64.53% (Cu = 15%) by Cu-doping proved the existence of CuO and oxygen rich phase. The lower absorption and high transmittance in visible region observed at Cu = 5% described the good optical quality of the sample with low scattering or absorption losses which leads to the industrial applications especially as transparent electrode. The high energy gap at Cu = 5% could be attributed to the poor crystallinity of the sample. The red shift in energy gap after Cu = 5% was explained by the p-d spin-exchange interactions between the band electrons and the localized d electrons of Cu2+ ions. The change in intensity and peak position of infrared (IR) peaks confirmed the presence of Cu in Znsbnd Ysbnd O lattice and also expressed the perturbation generated by Cu in Znsbnd Ysbnd O lattice.

  20. Optical enhancement of Au doped ZrO2 thin films by sol-gel dip coating method

    Science.gov (United States)

    John Berlin, I.; Joy, K.

    2015-01-01

    Homogeneous and transparent Au doped ZrO2 thin films were prepared by sol-gel dip coating method. The films have mixed phase of tetragonal, monoclinic and face centered cubic with crack free surface. Due to the increase in Au doping concentration many-body interaction occurs between free carriers and ionized impurities causing decrease in optical band gap from 5.72 to 5.40 eV. Localized surface plasmon resonance peak of the Au doped films appeared at 610 nm. Conversion of photons to surface plasmons allows the sub-wavelength manipulation of electromagnetic radiation. Hence the prepared Au doped ZrO2 thin films can be applied in nanoscale photonic devices such as lenses, switches, waveguides etc. Moreover the photoluminescence (PL) intensity of Au doped ZrO2 thin films decrease due to decrease in the radiative recombination, life time of the excitons and suppression of grain growth of ZrO2 with increasing Au dopant.