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Sample records for gel immunodiffusion test

  1. Comparison of agar gel immunodiffusion test, enzyme-linked immunosorbent assay and PCR in diagnostics of enzootic bovine leukosis

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    Malovrh Tadej

    2005-01-01

    Full Text Available Bovine leukaemia virus (BLV is a retrovirus that induces a chronic infection in cattle. Once infected, cattle remain virus carriers for life and start to show an antibody response within a few weeks after infection. Eradication and control of the disease are based on early diagnostics and segregation of the carriers. The choice of a diagnostic method depends on the eradication programme, money resources and characteristics of the herd to be analysed. The agar gel immunodiffusion (AGID test has been the serological test of choice for routine diagnosis of serum samples. Nevertheless, in more recent years, the enzyme-linked immunosorbent assay (ELISA has replaced the AGID for large scale testing. For this purpose, commercially available BLV-ELISA kits were compared to the AGID and to the polymerase chain reaction (PCR method performed with two sets of primers, amplifying env region. The ELISA kit based on the p24 core protein was found to be less specific and served as a screening test. The ELISA kit based on the envelope glycoprotein (gpSI served as a verification test and gave a good correlation with the AGID test and PCR method. However, ELISA showed a higher sensitivity than AGID. The p24 based ELiSA was useful for screening a large number of samples, whereas gp51 based ELISA, AGID and PCR were more important for detecting the antibody response against the individual BLV-proteins and therefore for verification of the infection with BLV.

  2. Enzootic bovine leukosis: prevalence of seric antibodies on dairy cows breed at Bahia and comparison between results of ELISA tests and ágar gel immunodiffusion tests

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    Paulo Ferreira de Matos

    2005-06-01

    Full Text Available Determinou-se a prevalência de infecção pelo vírus da Leucose Enzoótica dos Bovinos (LEB em animais criados na bacia leiteira de cinco micro-regiões do Estado da Bahia, comparando a eficiência de três provas sorológicas para detecção de anticorpos anti-Vírus da LEB: Teste ELISA, prova de Imunodifusão IDGA / gp 51 importado e a IDGA / gp 51 produzido pelo Instituto de Tecnologia do Paraná - TECPAR. Foram utilizados bovinos de 13 propriedades, totalizando 796 animais. A infecção pelo VLB foi detectada em todos os rebanhos, com taxa de prevalência de 41,0%, com variação de 6,3% (4/64 a 65,8% (25/38. Os bovinos foram estratificados em seis grupos etários: a de dois a seis meses; b de 7 a 12 meses; c de 13 a 24 meses; d entre 25 e 48 meses; e de 49 a 72 meses; f com mais de 72 meses de idade, observando-se que os índices de infecção aumentaram significativamente com o desenvolvimento etário e os resultados foram, respectivamente: 8,8%; 16,9%; 17,7%; 50,8%; 54,4% e 56,5%. Em 434 amostras avaliou-se comparativamente a eficiência das três provas sorológicas, considerando-se o Teste ELISA como padrão. Na comparação entre a prova ELISA e o Teste de IDGA / gp 51 importado a sensibilidade foi de 85% e especificidade de 80%, com valor preditivo positivo (VPP de 63% e o valor preditivo negativo (VPN de 93%, sendo a concordância igual a 81%. O estudo comparativo do teste ELISA e IDGA / gp 51 - TECPAR apresentou sensibilidade igual a 82% e a especificidade 93%, com VPP de associação igual a 79% e o VPN de 93% , sendo a concordância igual a 85%. Os resultados dos estudos comparativos sugerem IDGA com antígeno de procedência nacional suficientemente eficiente para a sua utilização.

  3. Evaluation of the Double Agar Gel Immunodiffusion Test and of the Enzyme-Linked Immunosorbent Assay in the Diagnosis and Follow-Up of Patients with Chronic Pulmonary Aspergillosis.

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    Priscila Zacarias de Azevedo

    Full Text Available The diagnosis of chronic pulmonary aspergillosis (CPA depends on the radiologic image and the identification of specific antibodies. The present study aimed to evaluate accuracy parameters of enzyme-linked immunosorbent assay (ELISA and of the determination of serum galactomannan level in the diagnosis of patients with CPA, comparing these results with the double agar gel immunodiffusion (DID test. In addition, the prevalence of cross-reactivity and the serological progression after treatment were evaluated by comparing DID and ELISA. Six study groups were formed: G1: 22 patients with CPA, 17 of whom had Aspergillus fungus ball, one chronic cavitary pulmonary aspergillosis (CCPA and four chronic fibrosing pulmonary aspergillosis (CFPA; G2: 28 patients with pulmonary tuberculosis (TB; G3: 23 patients with histoplasmosis (HST; G4: 50 patients with paracoccidioidomycosis (PCM; G5: 20 patients with cryptococcosis (CRC; and G6: 200 healthy controls. Serum antibodies were measured by DID and ELISA, with two antigen preparations--Aspergillus fumigatus (DID1, ELISA1 and a pool of A. fumigatus, A. flavus and A. niger antigens (DID2, ELISA2. The Platélia Aspergillus Enzyme Immunoassay (EIA kit was used to measure galactomannan. The cut-off points of ELISA were determined for each antigen preparation and for the 95% and 99% confidence intervals. Despite the low sensitivity, DID was the technique of choice due to its specificity, positive and negative predictive values and positive likelihood ratio-especially with the antigen pool and due to the low frequency of cross-reactivity. ELISA1 and a 0.090 cut-off showed high sensitivity, specificity and negative predictive value, but a high frequency of cross-reactivity with CRC. The best degree of agreement was observed between ELISA1 and ELISA2. The detection of serum galactomannan showed high sensitivity, comparable to ELISA2. The immunodiffusion test showed an excellent relationship with the progression after

  4. Rapid serum agglutination and agar gel immunodiffusion tests associated to clinical signs in rams experimentally infected with Brucella ovis Teste de soro aglutinação rápida e do teste de imunodifusão em gel de ágar associados aos sinais clínicos em carneiros infectados experimentalmente com Brucella ovis

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    Cristiane Nakada Nozaki

    2011-08-01

    Full Text Available The purpose of this study was to evaluate the agar gel immunodiffusion and the rapid serum agglutination tests associated to clinical signs in rams experimentally infected with Brucella ovis. The serological profile during the 12 months of infection showed a large fluctuation of antibodies that favors the failure in the diagnostic. The evaluation of tests after the experimental infection allowed to suggest that none of the tests were able to detect the infection throughout the period of study. The study reinforces the importance of considering the clinical signs to support the diagnosis of Brucella ovis infection in rams.O objetivo deste estudo foi avaliar o uso do teste de imunodifusão em gel de ágar e o teste sorológico de aglutinação rápida comparados aos sinais clínicos em carneiros infectados experimentalmente com Brucella ovis para o diagnóstico confirmatório da brucelose ovina. O perfil sorológico durante os 12 meses pós-infecção mostrou flutuação da resposta por anticorpos, que favorece a falha no diagnóstico. A avaliação dos testes indicou que nenhum dos testes foi capaz de detectar a infecção durante todo o período de estudo. O estudo ressalta a importância de considerar os sinais clínicos para apoiar o diagnóstico confirmatório da infecção por Brucella ovis em carneiros.

  5. Recombinant envelope protein (rgp90) ELISA for equine infectious anemia virus provides comparable results to the agar gel immunodiffusion.

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    Reis, Jenner K P; Diniz, Rejane S; Haddad, João P A; Ferraz, Isabella B F; Carvalho, Alex F; Kroon, Erna G; Ferreira, Paulo C P; Leite, Rômulo C

    2012-03-01

    Equine infectious anemia (EIA) is an important viral infection affecting horses worldwide. The course of infection is accompanied generally by three characteristic stages: acute, chronic and inapparent. There is no effective EIA vaccine or treatment, and the control of the disease is based currently on identification of EIAV inapparent carriers by laboratory tests. Recombinant envelope protein (rgp90) was expressed in Escherichia coli and evaluated via enzyme-linked immunosorbent assay (ELISA). There was an excellent agreement (95.42%) between the ELISA results using rgp90 and agar gel immunodiffusion test results. AGID is considered the "gold-standard" serologic test for equine infectious anemia (EIA). After 1160 serum samples were tested, the relative sensitivity and specificity of the ELISA were 96.1% and 96.4%, respectively. Moreover, analysis diagnostic accuracy of the ELISA was performed. The ELISA proved robust. Furthermore, good reproducibility was observed for the negative controls and, positive controls for all plates tested. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. The preparation of Dermatophilus congolensis antigen and its testing by means of immunodiffusion test and electrophoresis

    OpenAIRE

    Djaenudin Gholib; Subiyanto

    1998-01-01

    The filtrate antigen ofDermatophilus congolensis was prepared based on the Makinde method, whereas the whole cell antigen was based on the Bida and Kelley method. Filtrate antigen of Dermatophilus congolensis has been tested with positive serum from experimental animals, guinea pigs and sheep by means of immurrodiffitsion test and electrophoresis . Positive serum was produced by inoculation of whole cell antigen of D. congolensis to the animals . The results showed that the immunodiffusion te...

  7. Produção de antígeno nucleoprotéico do vírus da artrite-encefalite caprina e comparação com o do vírus Maedi-Visna para utilização em teste de imunodifusão em ágar gel CAEV nucleoproteic antigen production and comparison with Maedi-Visna antigen in the immunodiffusion test

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    Silvio R. O. Abreu

    1998-04-01

    Full Text Available Foi feita uma comparação entre os antígenos (Ag, preparados a partir dos vírus Maedi-Visna (MVV e Artrite-encefalite Caprina (CAEV para detecção de anticorpos contra o CAEV em 120 amostras de soro caprino. A sensibilidade e especificidade relativa da imunodifusão em ágar gel (IDAG usando-se Ag MVV em relação ao Ag CAEV, foi 77,3% e 100%, respectivamente (X2, pA comparison of Maedi-Visna virus (MVV and Caprine Arthritis-encephalitis virus (CAEV antigens for detection of antibodies to CAEV was performed using sera from 120 goats. The sensitivity and specificity of the immunodiffusion test using MVV antigen compared to that of CAEV antigen was 77.3% and 100%, respectively (X2, p < 0.01. These results suggested that only CAEV antigen should be used in immunodiffusion tests for CAEV diagnosis.

  8. Comparative study of agar gel immunodiffusion (AGID protocols for the diagnosis of equine infectious anemia in Brazil

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    Fernanda Gonçalves Oliveira

    2014-02-01

    Full Text Available To evaluate the Equine Infectious Anemia (EIA agar gel immunodiffusion (AGID protocols, two different kits commercially available in Brazil were used: an imported kit (kit A and a domestically produced kit (kit B. Kit A was submitted to the protocols recommended by the World Organization for Animal Health (OIE and the protocol recommended by the Ministério da Agricultura Pecuária e Abastecimento (MAPA. Kit B, the Brazilian kit, was submitted only to the MAPA-recommended protocol and was used as a reference in this study. A total of 345 equid serum samples, including field samples, serum sets from official laboratories and a weak positive serum control from National Veterinary Services Laboratories (NVSL, were used. Parameters such as the sensitivity of kit A in the two protocols, the detection limit of kits and the occurrence of nonspecific reactions or non-identity were evaluated. When Kit A was used for an AGID procedure performed according to the OIE-recommended protocol, the kit demonstrated good agreement with kit B and 99 % relative sensitivity. However, when kit A was processed according to the MAPA-recommended protocol, it failed to detect 1.16 % of weak positive samples and its relative sensitivity decreased to 96 %. The detection limit of kit A was lower than the detection limit of kit B for weak positive samples in both protocols. The occurrence of nonidentity reactions was higher with kit B than with kit A. The training of veterinarians to ensure the correct execution of the AGID test protocol should be intensified in Brazil.

  9. The preparation of Dermatophilus congolensis antigen and its testing by means of immunodiffusion test and electrophoresis

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    Djaenudin Gholib

    1998-10-01

    Full Text Available The filtrate antigen ofDermatophilus congolensis was prepared based on the Makinde method, whereas the whole cell antigen was based on the Bida and Kelley method. Filtrate antigen of Dermatophilus congolensis has been tested with positive serum from experimental animals, guinea pigs and sheep by means of immurrodiffitsion test and electrophoresis . Positive serum was produced by inoculation of whole cell antigen of D. congolensis to the animals . The results showed that the immunodiffusion test resulted in one and two precipitation lines with positive serum of sheep and guinea pigs respectively. Electrophoresis SDS-PAGE presented about 8 bands with molecular weight in the range from above 30 kD to more than 94 kD. The bands were then transferred into nitrocellulose membrane and gave positive reaction with positive serum from sheep.

  10. Investigation on the status of Johne's disease based on agar gel immunodiffusion, ziehl-neelsen staining and nested PCR approach in two cattle farm

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    Anand Mohan,

    2013-08-01

    Full Text Available Background and Methods: Paratuberculosis is a chronic disease of ruminant, caused by Mycobacterium avium subsp. paratuberculosis (Map, clinically infected animals produce high level of antibodies in blood and shed detectable amount of Map organisms in feces. Several serological and molecular tests are utilized for detection of antibodies or DNA of the organism in clinical samples. Present study indicates the status of paratuberculosis in two distinct cattle farms with different organizational set-ups viz. organized and unorganized. We used agar gel immunodiffusion (AGID assay for the detection of antibodies in blood. Ziehl-Neelsen (ZN staining of fecal smears was done to observe acid-fast bacilli and Nested PCR targeted to IS900 and f57 sequences, was performed to confirm the pathogen.Results: Sera samples of cattle, from organized farm, did not show any visible precipitating band with AGID assay. However, fecal smears of few cattle (3.57% were positive for acid-fast bacilli. When confirmed with nested PCR, only one fecal sample (0.71% was found positive for Map. In case of unorganized farm, a large number of cattle (38.75% showed precipitating antibodies with AGID assay and the percentage of fecal smears that showed acid-fast bacilli was 26.62%. Nevertheless, fecal samples containing Map DNA was confirmed in 14.37% of fecal sample by nested PCR.Conclusions: An organized farm, with better hygiene and management practices, showed lesser occurrence of paratuberculosis in cattle in comparison to unorganized farm. Not all AGID assays positive cattle might be an efficient shedder of Map and mare detection of acid-fast bacilli in fecal smears did not always indicate the presence of Map organism. Cattle infected with JD were mostly in the age group of six years and above.

  11. Investigation on the status of Johne's disease based on agar gel immunodiffusion, ziehl-neelsen staining and nested PCR approach in two cattle farm

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    Anand Mohan,; Pranabananda Das,; Neelam Kushwaha,; Kaliaperumal Karthik; Ankush Kiran Niranjan

    2013-01-01

    Background and Methods: Paratuberculosis is a chronic disease of ruminant, caused by Mycobacterium avium subsp. paratuberculosis (Map), clinically infected animals produce high level of antibodies in blood and shed detectable amount of Map organisms in feces. Several serological and molecular tests are utilized for detection of antibodies or DNA of the organism in clinical samples. Present study indicates the status of paratuberculosis in two distinct cattle farms with different organizationa...

  12. Re-evaluation of the haptoglobin reference values with the radial immunodiffusion technique

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    Rijn, H.J.M. van; Schreurs, W.H.P.; Schrijver, J.

    1984-01-01

    The reference values of the three main types of serum haptoglobin Hp 1-1, Hp 2-1, and Hp 2-2, as determined by radial immunodiffusion and with phenotype determination on polyacrylamide gel electrophoresis have been re-evaluated for both sexes. For that purpose about 500 serum samples were collected

  13. THE DIAGNOSTIC VALUE EVALUATION OF SPECIFIC IMMUNE RESPONSE THROUGH IMMUNODIFFUSION SIMPLE RADIAL TEST (I.D.S.R. APPLICATION IN OVINE ESTROSIS

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    DANIELA MOŢ

    2007-10-01

    Full Text Available Were been examined 20 blood samples from reformed sheep with ovine oestrosis.The sheep were then slaughtered and the necropsy of their heads confirms thepresence of Oestrus ovis larvae. A brut antigen was prepared from O. ovis larvaefrom I, II and III stadiums of evolution, after Bautista method (1982, with a proteiccontent of 3.84 total protein/ml serum (P.T.. The obtained results after I.D.S.R. testemphasized that O.ovis larvae induced in infected animals immunologicalreorganizations characterized through antibodies synthesis in dependence oninfestation degree. The results of I.D.S.R. test indicates this method for an immunereaction through antibodies syinthesis evaluation in O. ovis infested sheep, but itcan't be use for an ovine oestrosis diagnostic purpose, because has 0.83 sensibilityand 0.50 specificity.

  14. Evaluation of a New and Rapid Serologic Test for Detecting Brucellosis: Brucella Coombs Gel Test.

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    Hanci, Hayrunisa; Igan, Hakan; Uyanik, Muhammet Hamidullah

    2017-01-01

    Many serological tests have been used for the diagnosis of human brucellosis. A new serological method is identified as Brucella Coombs gel test based on the principle of centrifugation gel system similar to the gel system used in blood group determination. In this system, if Brucella antibodies were present in the serum, antigen and antibody would remain as a pink complex on the gel. Otherwise, the pink Brucella antigens would precipitate at the bottom of the gel card system. In this study, we aimed to compare the Brucella Coombs gel test, a new, rapid screen and titration method for detection of non-agglutinating IgG with the Brucella Coombs test. For this study, a total of 88 serum samples were obtained from 45 healthy persons and 43 individuals who had clinical signs and symptoms of brucellosis. For each specimen, Rose Bengal test, standard agglutination test, Coombs test and Brucella Coombs gel test were carried out. Sensitivity and specificity of Brucella Coombs gel test were found as 100.0 and 82.2%, respectively. Brucella Coombs gel test can be used as a screening test with high sensitivity. By the help of pink Brucella antigen precipitation, the tests' evaluation is simple and objective. In addition, determination of Brucella antibody by rapid titration offers another important advantage.

  15. Comparison of agal gel precipitation test (AGPT) and enzyme linked ...

    African Journals Online (AJOL)

    The use of agar gel precipitation test (AGPT) and enzyme linked immunosorbent assay (ELISA) in assaying for the presence of infectious bursal disease (IBD) virus antibody in village chickens in Oyo State, Nigeria, was compared. Out of 400 sera subjected to ELISA, 360 (90%) samples where positive for IBD virus ...

  16. Immunodiffusion Studies of Purified Equine Infectious Anemia Virus

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    Nakajima, Hideo; Ushimi, Chuzo

    1971-01-01

    Antigenicity of purified equine infectious anemia (EIA) virus was examined by immunodiffusion against sera obtained from horses experimentally infected with EIA virus. The purified virus reacted with the infected horse serum, and virus-specific precipitating antibody was demonstrated. Furthermore, it was found that purified EIA virus reacted against the serum of horses infected with all strains of EIA virus which were antigenically different from one another. From the result, group-specific components of the virus rather than strain-specific ones were considered to be involved in the reaction. Serological reactivity was lost by adding antiserum from the infected horse to the antigen. The precipitating antibody usually appeared in the serum 1 to 2 weeks after the first febrile attack of EIA and remained for a longer period. Some characteristics of the purified antigen and specificity of the reaction for EIA are described. Images PMID:16557982

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

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    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.

  18. Evaluation of standard reagents for radial-immunodiffusion assays. In vitro control of rabies vaccines

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    MICELI Graciela S.

    2000-01-01

    Full Text Available The RID assay is one of the in vitro methods used for in-process control in the production of rabies vaccines for veterinary use. It has been shown to be very useful for determining antigen concentration in the final bulk product. The work presented in this paper, including the production and standardization of candidate standard reagents for use in the Radial Immunodiffusion Assay (RID was carried out at the Pan American Institute for Food Protection and Zoonoses (INPPAZ/PAHO/WHO. The study was completed with the cooperation of the Faculty of Veterinary Sciences, National University of La Plata (NULP, Argentina, where the validation of the proposed standards and the quality control of samples from 28 different batches of rabies vaccines produced with Pasteur strain rabies virus (PV in BHK cells were performed. The activity of the vaccines was determined by in vivo (NIH and in vitro (RIDassays. The results of the candidate reagents for the reagent standardization tests showed stability, sensitivity and reproducibility. The Relative Potency the 1.2 between the problem vaccines and the reference vaccine was estimated by variance and regression analysis. The results of our validation study show that the INPPAZ (PAHO/WHO is capable of producing and distributing the above-mentioned standard reagents, as well as of providing support for the incorporation of the RID technique (sensitive, rapid and inexpensive to the laboratories that manufacture rabies vaccines in Latin America and the Caribbean.

  19. Characterisation of Fracture Behaviour of Starch Gels Using Conventional Fracture Mechanics and Wire Cutting Tests

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    Gamonpilas, C.; Charalambides, M. N.; Williams, J. G.; Dooling, P. J.; Gibbon, S. R.

    2008-07-01

    The fracture behaviour of starch gels is investigated through experimental tests and finite element simulations. Both conventional fracture and wire cutting experiments were performed. The results from these two tests were consistent with the fracture toughness increasing with loading rate. In the FE analysis, a non-linear elastic constitutive relationship was used to model the starch gels and frictionless condition was assumed between the wire-starch gel contact interface. A failure criterion based on critical fracture strain was assumed. Predictions of the steady-state cutting force at various wire diameters were found to be in good agreement with the wire cutting data.

  20. Does the degree of polymerization of haptoglobin influence the results of the radial immunodiffusion assay?

    NARCIS (Netherlands)

    Rijn, H.J.M. van; Wisman, J.P.W.; Meyling, F.G.

    1987-01-01

    The degree of polymerization of haptoglobin (Hp) phenotypes 2-1 and 2-2 was studied. In individual samples the degree of polymerization tends to be positively correlated with the Hp concentration as determined by the radial immunodiffusion technique (RID), while an inverse relationship between the

  1. Comparison of Excretory-Secretory and Somatic Antigens of Ornithobilharzia turkestanicum in Agar Gel Diffusion Test

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    H Miranzadeh

    2008-12-01

    Full Text Available Background: Ornithobilharziosis as one of the parasitic infections may give rise to serious economic problems in animal husbandry. The Aim of the study was to prepare and compare the somatic and excretory-secretory (ES antigens of O. tur­kestanicum in gel diffusion test. Methods: Excretory-secretory (ES and somatic antigens of Ornithobilharzia turkestanicum were prepared from collected worms from mesentric blood vessels of infected sheep. The laboratory bred rabbits were immunized with antigens and then antisera were prepared. The reaction of antigens and antisera was observed in gel diffusion test. Results: ES antigens of this species showed positive reaction with antisera raised against ES and also somatic antigens. Somatic antigens also showed positive reaction with antisera raised against somatic and also ES antigens. Conclusion: The antigenicity of O. turkestanicum ES and somatic antigens is the same in gel diffusion test.

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

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    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.

  3. In situ coronary stent paving by Pluronic F127-alginate gel blends: Formulation and erosion tests.

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    Dalmoro, Annalisa; Barba, Anna Angela; Grassi, Mario; Grassi, Gabriele; Lamberti, Gaetano

    2016-07-01

    In this work the development of an experimental protocol to perform the in situ gel-paving of coronary stent is presented. Biocompatible aqueous blends of Pluronic F127 and sodium alginates are used as potential drug dosage system for pharmacological in situ treatment of coronary in-stent restenosis. Pluronic F127/alginate aqueous blend has the unique characteristic to be liquid at room condition and to form gel at physiological temperature. The proposed protocol is based on the blend injection on stent wall previously implanted in a flexible silicon pipe mimicking the coronary artery. Injected blend is warmed up until human body temperature achieving a soft gel, then it is reticulated by copper bivalent ions to obtain an hard gel. To test the gel paving resistance to erosion phenomena when it is exposed to fluid flux (i.e. blood flux) a dedicated device, (the Simulated Artery Device, SAD), was built to simulate the human circulatory apparatus. The SAD is an hydraulic circuit in which a buffer solution (at pH 7.4) was fluxed by a peristaltic pump through the pipe hosting the covered stent. Erosion tests were performed monitoring, by gravimetric and spectrophotometric methods, the residual mass anchored to stent mesh after given times. The obtained results showed that the in situ gel-paving developed protocol was efficacious and reliable. The gel-paving was completely eroded in a time of the same order of magnitude of the physiological period required to restore the coronary lesion (subsequent to the atheroma removal) and of a pharmacological therapy to inhibit the in-stent-restenosis pathology. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1013-1022, 2016. © 2015 Wiley Periodicals, Inc.

  4. Gel-test: interpretation and value of a new technique for the detection of irregular antibodies.

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    Pottier, C; Quillet, P; Baufine-Ducrocq, H

    1992-01-01

    Here we report on our experience with the use of a 'Gel-Test' (DiaMed-ID Micro Typing System) technique for the detection and identification of irregular antibodies in a general hospital. This easy-to-use, standardized technique poses the question of the impact of its sensitivity on the specificity of the results. Of the 10% of observed positive reactions, 3.7% were irregular antibodies, 3.8% papain auto-antibodies, 1% cold antibodies and 2% not elucidated. Two hundred and eighteen irregular antibodies identified and titred with the 'gel-test' system were tested in parallel by 'tube' method. Sixty-three of these antibodies (29%) were not detected by the 'tube' method. While anti-Kell was always detected by both methods, we found the following false natives with the tube method: 15% anti-D, 32% anti-E, 42% anti-Cw and 58% anti-Lea. 68% of these false negatives had a low titre. The immunoglobulin class of the anti-E was studied; the sensitivity of the 'gel-test' system was associated with IgM in the anti-E. The sensitivity and standardization of the 'gel-test' technique guarantee greater safety in blood transfusion and increase efficiency in the prevention of foeto-maternal stimulation of anti-D.

  5. [Changes in the structure and clinical significance of the positive results of pretransfusion testing during the switching from tube test agglutination to gel microcolumn technique].

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    Petrusić-Kafedzić, Alma; Ivanković, Zdravko; Ekinović, Sabahudin; Hutinović, Aida; Ibrahimagić-Seper, Lejla

    2010-08-01

    To investigate the changes in pretransfusion testing during the switch from the agglutination tube test to the gel test. Clinical significance of positive results has been analyzed in 7667 pretransfusion tests (with 16610 cross-matches) performed by the tube test in 2005-2006, and in 7372 pretransfusion tests (with 17294 cross-matches) performed in 2007-2008 by the gel test. In both analyzed periods antibody detection was positive in 1.3% and cross-matching in 0.3% cases. At least one test was positive in 1.4% pretransfusions tested by the tube test and in 1.3% by the gel test, with >75% positive results in women. Analyzing cases with positive cross-matching but negative antibody detection, eight of ten such cases found by the tube test were caused by 'cold antibodies' whereas 'warm non-specific antibodies' caused all three cases found by the gel test. The gel test detected higher proportion of immune antibodies than the tube test (69.8% vs 41.3%, p antibodies. The tube test detected 24 cases of clinically non-significant antibodies, as compared with no cases found by the gel test (p antibodies' more often caused positive cross-matches than antibody detection (42.6% vs. 29.9% by the tube test, 28.9% vs. 18.3% by the gel test). Despite of being close in the detection of irregular antibodies (p=0.062), the difference between the tube and gel test was not significant. 'Non-specific antibodies' were found by both tests more often in women, while clinical departments were of no significance. The gel test has proved to be a more optimal technique of pretransfusion testing. The detection of irregular antibodies is recommended as an obligatory part of pretransfusion testing.

  6. Leuco-crystal-violet micelle gel dosimeters: II. Recipe optimization and testing

    Science.gov (United States)

    Nasr, A. T.; Alexander, K. M.; Olding, T.; Schreiner, L. J.; McAuley, K. B.

    2015-06-01

    In this study, recipe optimization of Leuco Crystal Violet (LCV) micelle gels made with the surfactant Cetyl Trimethyl Ammonium Bromide (CTAB) and the chemical sensitizer 2,2,2-trichloroethanol (TCE) was aided by a two-level three-factor designed experiment. The optimized recipe contains 0.75 mM LCV, 17.0 mM CTAB, 120 mM TCE, 25.0 mM tri-chloro acetic acid (TCAA), 4 wt% gelatin and ~96 wt% water. Dose sensitivity of the optimized gel is 1.5 times higher than that of Jordan’s standard LCV micelle gel. Spatial integrity of the 3D dose distribution information in 1L phantoms filled with this recipe is maintained for  >120 d. Unfortunately, phantoms made using the optimized recipe showed dose-rate dependence (14% difference in optical attenuation at the peak dose using electron beam irradiations at 100 and 400 MU min-1). Further testing suggests that the surfactant CTAB is the cause of this dose rate behaviour.

  7. The reverse single radial immunodiffusion technique for detecting antibodies to Dermatophilus congolensis.

    Science.gov (United States)

    Makinde, A A

    1980-04-26

    The reverse single radial immunodiffusion technique was used to detect Dermatophilus congolensis antibody in sera collected from animals previously infected to varying levels with D congolensis. Ammonium sulphate and trichloroacetic acid extracts of five different strains of D congolensis obtained from different geographical locations were used as antigens. All the extracts showed variations in their sensitivities in detecting D congolensis antibody in the various serum samples. Multiple antibodies were detected by some extracts while some showed negative antibody reaction to all extracts. Two extracts also showed cross-reactions with the serum from an animal that was infected by Nocardia species. Trichloroacetic acid extracts of all the strains were found to be more active serologically, detecting antibody in more sera and giving sharper and clearer reactions than ammonium sulphate extracts.

  8. Non-immunological precipitation by the neutral detergent triton X-100 in agar gel diffusion.

    OpenAIRE

    Mansheim, B J; Stenstrom, M L

    1980-01-01

    Triton X-100 can be used to clarify vague immunoprecipitin lines from bacterial antigens; however, non-immunological precipitation can lead to mistaken interpretation of immunodiffusion results. If Triton X-100 is added directly to the gel during preparation rather than to the antigen well, this detergent artifact can be eliminated.

  9. Good agreement of conventional and gel-based direct agglutination test in immune-mediated haemolytic anaemia

    Directory of Open Access Journals (Sweden)

    Piek Christine J

    2012-02-01

    Full Text Available Abstract Background The aim of this study was to compare a gel-based test with the traditional direct agglutination test (DAT for the diagnosis of immune-mediated haemolytic anaemia (IMHA. Methods Canine (n = 247 and feline (n = 74 blood samples were submitted for DAT testing to two laboratories. A subset of canine samples was categorized as having idiopathic IMHA, secondary IMHA, or no IMHA. Results The kappa values for agreement between the tests were in one laboratory 0.86 for canine and 0.58 for feline samples, and in the other 0.48 for canine samples. The lower agreement in the second laboratory was caused by a high number of positive canine DATs for which the gel test was negative. This group included significantly more dogs with secondary IMHA. Conclusions The gel test might be used as a screening test for idiopathic IMHA and is less often positive in secondary IMHA than the DAT.

  10. Evaluation of a particle gel immunoassay as a screening test for syphilis.

    Science.gov (United States)

    Borelli, S; Monn, A; Meyer, J; Berger, U; Honegger, H P; Lautenschlager, St

    2009-02-01

    Recent trends in Western Europe show an increase in sexually transmitted infections. Surveillance data in Switzerland confirm this rising trend. Notifications of syphilis cases nearly doubled in the year 2002 and almost tripled in 2003. This trend necessitates an early correct diagnosis making reliable screening tests mandatory. In the presented study a particle gel immunoassay (ID-PaGIA syphilis antibody test, Diamed) using recombinant treponemal antigens TpN15, TpN17 and TpN47 was evaluated as a screening test in comparison to the currently used Treponema pallidum particle agglutination test (Serodia-TPPA, Fujirebio). Serum samples were obtained from a cross-sectional sero-epidemiological study among men who have sex with men. Samples were tested with the PaGia and the TPPA. In the case of equivocal results a titrated TPPA of an external laboratory was used as a confirmation test. In total 650 serum samples (48 seropositive patients, 602 negative) were evaluated. The PaGIA showed a sensitivity of 0.89 (43/48) and the TPPA of 0.83 (40/48). This difference was not statistically relevant (p = 0.4). The particle gel assay showed a significantly higher specificity (1.0) compared to the TPPA (0.98) (p = 0.004). The PaGIA showed a sensitivity comparable to that of other treponemal tests with an even better specificity. Advantages of the PaGIA are the fast reaction time of only 20 min and the simplicity of the procedure with minimal technical equipment.

  11. Changes in the structure and clinical significance of the positive results of pretransfusion testing during the switching from tube test agglutination to gel microcolumn technique

    Directory of Open Access Journals (Sweden)

    Petrušić-Kafedžić Alma

    2010-08-01

    Full Text Available im To investigate the changes in pretransfusion testing during the switch from the agglutination tube test to the gel test. Methods Clinical significance of positive results has been analyzed in 7667 pretransfusion tests (with 16610 cross-matches performed by the tube test in 2005-2006, and in 7372 pretransfusion tests (with17294 cross-matches performed in 2007-2008 by the gel test. ResultsIn both analyzed periods antibody detection was positive in 1.3% and cross-matching in 0.3% cases. At least one test was positive in 1.4%pretransfusions tested by the tube test and in 1.3% by the gel test,with >75% positive results in women. Analyzing cases with positive cross-matching but negative antibody detection, eight of ten such cases found by the tube test were caused by ‘cold antibodies’whereas‘warm non-specific antibodies’ caused all three cases found by the gel test. The gel test detected higher proportion of immune antibodies than the tube test (69.8% vs 41.3%, p<0.001, with a double increase in anti-K and Rh antibodies. The tube test detected 24 cases of clinically non-significant antibodies, as compared with no cases found by the gel test (p<0,001. ‘Non-specific antibodies’ more often caused positive cross-matches than antibody detection(42.6% vs. 29.9% by the tube test, 28.9% vs. 18.3% by the gel test. Despite of being close in the detection of irregular antibodies (p=0.062, the difference between the tube and gel test was not significant. ‘Non-specific antibodies’ were found by both tests more often in women, while clinical departments were of no significance.Conclusion The gel test has proved to be a more optimal technique of pretransfusion testing. The detection of irregular antibodies isrecommended as an obligatory part of pretransfusion testing.

  12. Good agreement of conventional and gel-based direct agglutination test in immune-mediated haemolytic anaemia

    NARCIS (Netherlands)

    Piek, C.J.; Teske, E.; van Leeuwen, M.W.; Day, M.J.

    2012-01-01

    Abstract Background The aim of this study was to compare a gel-based test with the traditional direct agglutination test (DAT) for the diagnosis of immune-mediated haemolytic anaemia (IMHA). Methods Canine (n = 247) and feline (n = 74) blood samples were submitted for DAT testing to two

  13. Use of hot set and gel content test in QA/QC for irradiation of commercial products

    International Nuclear Information System (INIS)

    Ruzalina Baharin; Siti Aiasah Hashim; Zulkafli Ghazali; Zarina Mohd Noor

    2006-01-01

    Currently, irradiation of polyolefin heat shrinkable tube is the main commercial activity at Alurtron. Other products include medical devices and cosmetic products. As required by the quality management system, ISO 9001:2000, Alurtron is responsible to ensure that customer received their irradiation dose as requested. At present two test methods are employed namely, hot set and gel content measurement to verify received dose . Hot set test is a physical test to determine longitudinal shrinkage of the irradiated products. Whereas gel content measurement determine to certain extend the degree of crosslinking occurred in polymeric material upon irradiation, in the customer products. Both test are routinely used to cross-check the dose required by customer. This paper outlines the correlation between hot set and gel content measurement of customer products. (Author)

  14. PREVALÊNCIA SOROLÓGICA DA MAEDI-VISNA EM REBANHOS OVINOS DA MICRORREGIÃO DE JUAZEIRO - BAHIA POR MEIO DO TESTE DE IMUNODIFUSÃO EM GEL DE ÁGAR

    Directory of Open Access Journals (Sweden)

    PRISCILA MARTINEZ MARTINEZ

    2011-06-01

    Full Text Available The introduction of new breeds, aiming at increasing productivity, caused the change in the health profile of herds. Among the diseases introduced in Brazil lentiviroses of small ruminants (LVPR stand out,represented by caprine arthritis encephalitis (CAE and the maedi-visna (MV. In order to obtain data concerning the presence of maedi visna (MV in sheep herds in the microregion of Juazeiro, Bahia, 91 9 serum samples were evaluated by agar gel immunodiffusion (AGID. Thesamples were collected in eight cities that make up this microregion Juazeiro, Sento Sé, Sobradinho, Pilão Arcado, Campo Alegre Lourdes, Remanso, Casa Nova and Curaçá considering how representative eachmunicipality is within the totalilty of animals. It was observed that 0.34% of the sampled sheep showed positive reaction in the AGID. It was concluded that the MV occurs with low prevalence in the studied microregion, probably due to the predominance of locallyadapted breeds.

  15. Decisive test of the ideal behavior of tetra-PEG gels

    Science.gov (United States)

    Horkay, Ferenc; Nishi, Kengo; Shibayama, Mitsuhiro

    2017-04-01

    The objective of this work is to investigate the thermodynamic and scattering behavior of tetra-poly(ethylene glycol) (PEG) gels. Complementary measurements, including osmotic swelling pressure, elastic modulus, and small angle neutron scattering (SANS), are reported for a series of tetra-PEG gels made from different molecular weight precursor chains at different concentrations. Analysis of the osmotic swelling pressure vs polymer volume fraction curves makes it possible to separate the elastic and mixing contributions of the network free energy. It is shown that in tetra-PEG gels these free energy components are additive. The elastic term varies with the one-third power of the polymer volume fraction and its numerical value is equal to the shear modulus obtained from independent mechanical measurements. The mixing pressure of the cross-linked polymer is slightly smaller than that of the corresponding solution of the uncross-linked polymer of infinite molecular weight but it exhibits similar dependence on the polymer concentration. The observed deviation between the osmotic mixing pressures of the gel and the solution can be attributed to the presence of small amount of structural inhomogeneities frozen-in by the cross-links. SANS reveals that the scattering response of tetra-PEG gel is mainly governed by the thermodynamic concentration fluctuations of the network, i.e., the contribution from static inhomogeneities to the SANS signal is small.

  16. Detection of rubella-specific serum IgG and IgA and nasopharyngeal IgA responses using a radioactive single radial immunodiffusion technique

    International Nuclear Information System (INIS)

    Al-Nakib, W.; Best, J.M.; Banatvala, J.E.

    1975-01-01

    A radioactive, single radial immunodiffusion technique (RSRID) employing 125 I-labelled antiglobulins, was developed to determine rubella-specific serum IgG and IgA and nasopharyngeal IgA antibody responses following both naturally acquired rubella and vaccination with four attenuated vaccines. Rubella-specific IgG antibodies developed in parallel with haemagglutination inhibiting (HAI) antibodies and both persisted for at least a year in all cases of naturally acquired and vaccine induced infection. However, the RSRID test detected rises in titre in all of five volunteers challenged intranasally with RA27/3, whereas only one volunteer showed a rise by HAI. Serum IgA antibodies generally persisted for at least a year following naturally acquired infection but rubella vaccines induced variable responses. Thus, following administration of RA27/3 and To-336 vaccines, rubella-specific IgA usually persisted for a year, whereas Cendehill vaccine failed to induce a detectable response. Rubella-specific nasopharyngeal IgA was detected in all five patients following naturally acquired infection and was still present in the only two patients tested a year after infection. These antibodies were detected in fourteen of twenty-three vaccinees at 3 weeks, but persisted for a year in only two vaccinees, both of whom were given RA27/3 intranasally. (author)

  17. [Irregular antibodies. A comparative study of 2 series of 20,000 subjects: one with a conventional identification test, the other with gel-test].

    Science.gov (United States)

    Trophilme, C; Becker, A M; Jaffard, H P; Jaulin, P

    1995-01-01

    The results of irregular antibody screening in two successive series of 21485 and 19819 individuals were retrospectively analysed. All the irregular antibody screenings were performed with an autoanalyser according to Rosenfield and Lalezary [1, 2] but red cell antibody identification tests were not the same: conventional manual tests in the first series and gel-test Diamed in the second one. In spite of a bigger number of identification tests performed in the second series, the percentage of patients with irregular antibodies was approximately the same (2.27% and 2.22%) in each series. Analysis of identified specificities shows in the second series the increase of immune antibodies (+ 42.3%) especially antibodies with anti-Rh specificity and the decline of natural antibodies (- 28.9%) essentially of anti-Lewis b and P1 antibodies. The sensitivity of both the gel-test and the autoanalyser screening for identification of immune antibodies are more or less the same. The sensitivity of gel-test probably gives a safer transfusion but increases the workload of both the laboratory and the blood bank delivery service.

  18. Evaluation of a composite Gel-Alanine phantom on an end-to-end test to treat multiple brain metastases by a single isocenter VMAT technique.

    Science.gov (United States)

    Pavoni, Juliana Fernandes; Neves-Junior, Wellington Furtado Pimenta; da Silveira, Matheus Antonio; Haddad, Cecília Maria Kalil; Baffa, Oswaldo

    2017-09-01

    This work aims to evaluate the application of a cylindrical phantom made of dosimetric gel containing alanine pellets distributed inside the gel volume during an end-to-end test of a single isocenter VMAT for simultaneous treatment of multiple brain metastases. The evaluation is based on the comparison of the results obtained with the composite phantom with the treatment planning system (TPS) dose distribution validated by using the clinical conventional quality control with point and planar dose measurements. A cylindrical MAGIC-f gel phantom containing alanine dosimeters (composite phantom) was used to design the VMAT plan in the treatment planning system (TPS). The alanine dosimeters were pellets with radius of 2.5 mm and height of 3 mm, and played the role of brain metastasis inside the gel cylinder, which simulated the cerebral tissue. Five of the alanine dosimeters were selected to simulate five lesions; five planning target volumes (PTVs) were created including the dosimeters and irradiated with different doses. Conventional quality assurance (QA) was performed on the TPS plan and on the composite phantom; a phantom containing only gel (Gel 1 phantom) was also irradiated. One day after irradiation, magnetic resonance images were acquired for both phantoms on a 3T scanner. An electron spin resonance spectrometer was used to evaluate alanine doses. Calibration curves were constructed for the alanine and the gel dosimeters. All the gel only measurement was repeated (Gel 2 phantom) in order to confirm the previous gel measurement. The VMAT treatment plan was approved by the conventional QA. The doses measured by alanine dosimeters on the composite gel phantom agreed to the TPS on average within 3.3%. The alanine dose for each lesion was used to calibrate the gel dosimeter measurements of the concerned PTV. Both gel dose volume histograms (DVH) achieved for each PTV were in agreement with the expected TPS DVH, except for a small discrepancy observed for the Gel 2

  19. Iodine, krypton and xenon retention efficiencies of silver impregnated silica gel media with different silver loadings and under different test conditions

    International Nuclear Information System (INIS)

    Motes, B.G.; Fernandez, S.J.; Tkachyk, J.W.

    1983-02-01

    The purpose of an independent study conducted by Exxon Nuclear Idaho, Co. (ENICO) was to evaluate a silver impregnated silica gel adsorption medium associated with a radioiodine air sampler developed at Brookhaven National Laboratory (BNL). Specifically, ENICO's responsibility was to evaluate the iodine and noble gas retention efficiencies of the adsorption medium. The evaluation was comprised of a four-phase program: 1) test assemblies capable of challenging the silver silica gel filled adsorber canister with radioiodine species or noble gases at flow rates up to 10 scfm and relative humidities up to 83% were constructed; 2) more than 45 kgs of the 4 and 8% silver impregnated silica gel were prepared and characterized for particle size distribution, bulk silver content, bulk density, and silver content by particle size; 3) iodine species retention efficiencies of the silver silica gel were determined; and 4 krypton and xenon retention efficiencies were measured. The iodine species retention efficiencies were greater than 90% under most conditions. A combination of flow rates >5 scfm and 4% silver loaded silica gel reduced the methyl iodide retention efficiency to less than 90%. The retention efficiencies for both krypton and xenon were on the order of 8 x 10 -2 % and were not affected greatly by any test variable except test duration. A reduced retention efficiency with increased test durations indicates adsorption equilibrium may be established within five minutes. (author)

  20. Push-Pull-Tests in einer isolierten Einzelkluft - Geländeversuche und numerische Modellierung

    Science.gov (United States)

    Orilski, Judith; Wohnlich, Stefan

    2017-11-01

    Push-pull tests are a proven method for determining hydraulic parameters if there is only one borehole available. Test interpretation by numerical models is often coupled with difficulties due to the heterogeneity of the subsurface. In this field study, tracer-based push-pull-tests (using Eosin, Tinopal and chloride) were performed in an isolated fracture in sandstone. The empirical breakthrough curves were compared to those of an idealized numerical single-fracture model. The influence of individual transport and test properties was previously investigated by a sensitivity study. A simplified analytical method served to determine further transport properties. The idealized fracture was realized by a porosity of one, the tracer dilution in the borehole could be considered by a special input function. It was shown that the peak form caused by advective dominated processes could be reproduced quite well by the numerical model, whereas the tailing due to dispersive-diffusive processes could not be considered sufficiently accurate.

  1. Contamination in smooth gel breast implant placement: testing a funnel versus digital insertion technique in a cadaver model.

    Science.gov (United States)

    Moyer, Hunter R; Ghazi, Bahair; Saunders, Neil; Losken, Albert

    2012-02-01

    Overt infection and biofilm formation resulting from breast augmentation are rare but serious problems that can lead to contracture and a need for revision surgery. The Keller Funnel is a medical device composed of a rip-stop nylon sleeve with a hydrophilic inner coating. One claim of the funnel is that it facilitates a "no touch" technique, thereby limiting contamination. To date, there are no data to support this claim. The authors evaluate skin and breast parenchyma contamination with standard implantation techniques and the Keller funnel. Insertion techniques were tested in two fresh cadavers. Smooth, round, moderate-plus silicone gel implants were placed for each experiment. To quantify the amount of skin contamination, a 2% w/v fluorescein paste was painted onto the cadaver thorax. After implantation, the implants were soaked in 250 mL of sterile water, and the fluorescence emission of the resulting solution was measured with an ultraviolet-visible spectrophotometer. To qualify the potential contamination from breast parenchyma, the cadaver breast tissue was swabbed with methicillin-sensitive Staphylococcus aureus, and the implant surfaces were cultured postimplantation. The funnel resulted in a 27-fold decrease in skin contact for all smooth gel implants (P = .00059). The amount of skin contact and potential contamination increased incrementally with increasing implant volume when either the funnel or digital implantation techniques were used. Bacterial contamination from breast parenchyma was two times more likely with the standard digital insertion technique (P = .06). The Keller funnel appears to significantly reduce the amount of skin contact and potential parenchyma contamination.

  2. Eficiência diagnóstica de antígenos solúveis de Brucella em testes de imunodifusão e capacidade para diferenciar bovinos vacinados com Brucella abortus CEPA 19

    Directory of Open Access Journals (Sweden)

    José Daffner

    1999-01-01

    Full Text Available Three soluble antigens were compared by radial immunodiffusion (RID and agar gel immunodiffusion (AGID tests: a native haptene (NH from Brucella melitensis 16M, and a polysaccharide (PS from B. abortus 1119-3, both obtained by non-hydrolytic methods, and the (O-Chain polysaccharide extracted also from B. abortus 1119-3 but using an hydrolytic method. Three groups of bovine sera were tested: a Naturally infected (n = 76; b Non-infected (n = 130 and c S-19 vaccinated (n = 61; the sensitivity (Se, the specificity (Sp and the ability to differentiate vaccinated (ADV were determined in each group a, b and c respectively. The highest Se in the RID test (84.3% was achieved by NH; while the three antigens gave 100% Sp. The O-Chain showed 100% ADV in this test. In the AGID test PS antigen showed the best Se (86.6%, and all antigens showed 100% of Sp and ADV. Finally, for its production qualities and efficiency the antigens PS and NH represent a promising alternative for complementary diagnosis of brucellosis.

  3. Comparison of pulsed-field gel electrophoresis and enterobacterial repetitive intergenic consensus PCR and biochemical tests to characterize Lactococcus garvieae.

    Science.gov (United States)

    Ture, M; Altinok, I; Capkin, E

    2015-01-01

    Biochemical test, pulsed-field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR) were used to compare 42 strains of Lactococcus garvieae isolated from different regions of Turkey, Italy, France and Spain. Twenty biotypes of L. garvieae were formed based on 54 biochemical tests. ERIC-PCR of genomic DNA from different L. garvieae strains resulted in amplification of multiple fragments of DNA in sizes ranging between 200 and 5000 bp with various band intensities. After cutting DNA with ApaI restriction enzyme and running on the PFGE, 11–22 resolvable bands ranging from 2 to 194 kb were observed. Turkish isolates were grouped into two clusters, and only A58 (Italy) strain was connected with Turkish isolates. Similarities between Turkish, Spanish, Italian and French isolates were Turkey, first lactococcosis occurred in Mugla, and then, it has been spread all over the country. Based on ERIC-PCR, Spanish and Italian strains of L. garvieae were related to Mugla strains. Therefore, after comparing PFGE profiles, ERIC-PCR profiles and phenotypic characteristics of 42 strains of L. garvieae, there were no relationships found between these three typing methods. PFGE method was more discriminative than the other methods. © 2014 John Wiley & Sons Ltd.

  4. Fibrin gels loaded with cisplatin and cisplatin-hyaluronate complexes tested in a subcutaneous human melanoma model.

    Science.gov (United States)

    Viale, Maurizio; Rossi, Marta; Russo, Eleonora; Cilli, Michele; Aprile, Anna; Profumo, Aldo; Santi, Pierluigi; Fenoglio, Carla; Cafaggi, Sergio; Rocco, Mattia

    2015-12-01

    Fibrin gels are attractive biomaterials for local delivery of a variety of agents, from drugs to proteins. Similarly, polymer-anticancer-drug conjugates and nanoparticles are emerging as potential candidates for cancer treatment. Combining these different approaches, we have studied the efficacy of fibrin gels loaded with cisplatin (DDP) and a complex of DDP with hyaluronate (DDP-HA) for tumor growth inhibition in a melanoma model. Loaded gels prepared at relatively high fibrinogen concentration (22 mg/ml) showed good in vitro antiproliferative activities, prolonged release of the anticancer drug, and a long persistence (10-15 days) in vivo when implanted subcutaneously (sc) in immunodeficient mice. Gels loaded with DDP or DDP-HA containing 1/3 or even 1/6 of their systemic dose (6 mg/kg) and positioned under the tumor mass in mice bearing a sc human SK-Mel-28 tumor showed an antitumor activity better than that of the original parent compound given intraperitoneally (ip). Moreover, in an additional experiment in vivo, fibrin gels loaded with N-trimethyl chitosan-based nanoparticles containing a DDP-HA complex were assayed, resulting in a further 8 % improvement of anticancer activity, with lesser adverse systemic toxic effects. Taken together, these results suggest that the combination of fibrin gels and drugs complexed with suitable macromolecules holds great promise for loco-regional anticancer therapy of melanoma and other surgically removable cancer types.

  5. Evaluation of a new charge algorithm for a lead-acid battery with gelled electrolyte using a 96V gel cell 4 as a test battery

    Science.gov (United States)

    Nowak, Dieter K.

    1989-10-01

    A summary is reported of test results obtained utilizing the new UAH charge algorithm for Lead-Acid batteries with gelled electrolyte. The battery performance data for a 96V Phase 4 Gel/Cell battery pack was tested in a Jet Industries Electrica vehicle. It was shown that the new charge concept is sound although there can be problems with batteries that are highly imbalanced and where excessive electronic noise is experienced on the electronic signal feed-back line that carries the voltage sensor signals from the battery. Additional work is needed to add intelligence to the charge algorithm in terms of a better ability to extract the beginning of gas development from the voltage spread function. This can probably be accomplished by scanning the voltages more often and including that data into the function analysis by adding software filters. The Phase 4 Gel/Cell battery performance was found to be about 20 percent lower than that of the Phase 3 Gel/Cell battery. Problems with cell valve leakage were encountered in the Phase 4 Gel/Cell that pose a threat to battery life although so far no battery module has been lost.

  6. Evaluation of ram semen quality using polyacrylamide gel instead of cervical mucus in the sperm penetration test.

    Science.gov (United States)

    Martínez-Rodríguez, C; Alvarez, M; Ordás, L; Chamorro, C A; Martinez-Pastor, F; Anel, L; de Paz, P

    2012-05-01

    Fertility is a very complex biological function that depends on several properties of the spermatozoa, including sperm motility. Two objectives are analyzed in this study: (1) Replace the cervical mucus by a synthetic medium in a sperm penetration test, and (2) evaluating the results of this test objectively analyzing the sperm number that migrates. In experiment 1, we have tested eight concentrations of acrylamide (1%-2%). Rheological properties of media were analyzed. The plastic straws, loaded with acrylamide, were placed vertically on the semen sample tube for 15 min at 39 °C. After, the acrylamides were placed, by segments of 5 mm, into wells of a 24-well plate, dyed with Hoechst 33342 and the number of spermatozoa were calculated by automated microscopy analysis. The 1.55% and 1.6% acrylamide gel showed a number of spermatozoa emigrating closer to that seen with natural mucus. In experiment 2, we applied the sperm penetration in acrylamide 1.6% and 1.55% using fresh semen and cooled semen at 15 °C and 5 °C. The spermatozoa counts were performed for each segment of 10 mm. Semen chilled at 15 °C presented intermediate values of sperm counts in comparison with fresh semen (higher) and 5 °C chilled semen. The sperm counts do not differ between acrylamides but the rheological properties of acrylamide 1.6% were more similar to those of the natural cervical mucus. In experiment 3, we have observed significant correlations between the number of spermatozoa and several sperm quality parameters (positive: progressive motility and velocity according to the straight path; negative: damaged acrosomes and apoptotic cells) in 1.6% acrylamide media. We conclude that the size of the cell subpopulation, objectively calculated, that migrate beyond 20 mm in 0.5-mL straws filled with acrylamide is a useful parameter in ram sperm quality assessment and further studies are needed to evaluate its relationship with field fertility. Copyright © 2012 Elsevier Inc. All rights

  7. Estimation of the potential fertility based upon non-return rates of bulls: using polyacrylamide gel instead of cervical mucus in the sperm penetration test.

    Science.gov (United States)

    Taş, M; Bacinoglu, S; Cirit, U; Ozgümüş, S; Kaşgöz, H; Pabuccuoğlu, S

    2007-10-15

    In the present study, we aimed to develop a polyacrylamide gel that could be used instead of bovine cervical mucus in the cervical mucus penetration test (CMPT) to obtain coherent and replicable results in bulls. The frozen semen samples of six Holstein bulls, which were divided into two fertility groups as low and high according to their non-return rate (NRR), were used. In this study, the modified CMPT (mCMPT) was carried out within 0.25 mL transparent plastic straws with an inner diameter 1.7 mm. The penetration ability of spermatozoa to bovine cervical mucus and to polyacrylamide gels swollen with two different solutions [NaCl (G1) and PBS (G2)] was compared. For the penetration test, the straws filled with cervical mucus and both gels were dipped into thawed semen samples and incubated at 37 degrees C for 15 min. After the incubation, straws were frozen in liquid nitrogen vapour and stored at -20 degrees C. On the evaluation day, the frozen straws were cut at 1.5-1.75 cm (penetration distance range=PDR1), 3.25-3.5 cm (PDR2) and 5.0-5.25 cm (PDR3), beginning from open-end of the straws. The separated frozen parts were then immediately transferred onto special counting slides by pushing with a mandrel and left to thaw. Thawed samples were covered with cover glass and penetrated spermatozoa in these parts were counted. The relation between the results and fertility of bulls was determined. In the tests performed using mucus, the number of spermatozoa determined in the high fertility group was found to be higher at PDR3 (p<0.0001) compared to the low fertility group, while in G1 spermatozoa number was significantly higher at PDR1 and PDR3 (p<0.0001). However, in G2 medium, no significant difference was observed between either of the fertility groups with respect to spermatozoa number determined at all distance ranges. In the study, we have determined that the gel swollen with NaCl produces better results and this gel can be used instead of bovine cervical mucus

  8. Clinical evaluation of chemosensitivity testing for patients with unresectable non-small cell lung cancer (NSCLC) using collagen gel droplet embedded culture drug sensitivity test (CD-DST).

    Science.gov (United States)

    Kawamura, Masafumi; Gika, Masatoshi; Abiko, Tomohiro; Inoue, Yoshimasa; Oyama, Takahiko; Izumi, Yotaro; Kobayashi, Hisayuki; Kobayashi, Koichi

    2007-03-01

    In the present study, we prospectively evaluated the clinical feasibility and efficacy of collagen gel droplet embedded culture drug sensitivity test (CD-DST) in unresectable non-small cell lung cancer (NSCLC) without previous treatment. Eighty patients with unresectable NSCLC, aged less than 81 years old, PS 0-1, and with evaluable tumor lesions, entered the study. If the patient had CD-DST active drugs, more than three cycles of chemotherapy containing these drugs were administered. If the patient did not have CD-DST active drugs, the patient could choose any treatment including best supportive care. Of the 80 patients in this study, CD-DST yielded results successfully in 49 patients (61.3%). CD-DST active drugs were present in 22 patients, and significantly more female patients had in vitro active anticancer agents than male (P=0.0008). All of the patients with CD-DST active agents received chemotherapy including these agents. In these patients, the response rate was 72.7%, and median survival was 15.0 months. In the patients without CD-DST active agents, 11 patients received standard, empirical chemotherapy. In these patients, response rate was 0%, and median survival was 6.0 months. The results show that CD-DST is capable of selecting the responders and the respective optimal regimens, and also delineating the patients less likely benefit from treatment.

  9. In vitro-chemosensitivity test using the collagen gel droplet embedded culture drug test (CD-DST) for malignant pleural mesothelioma: possibility of clinical application.

    Science.gov (United States)

    Higashiyama, Masahiko; Oda, Kazuyuki; Okami, Jiro; Maeda, Jun; Kodama, Ken; Takami, Koji; Morinaga, Kenji; Takano, Toshikazu; Kobayashi, Hisayuki

    2008-12-01

    An in vitro-chemosensitivity test using the collagen gel droplet embedded culture drug test (CD-DST), established by Kobayashi et al. (Jpn J Cancer Res 2001; 92: 203-10), has been widely used on various tumors. This study retrospectively evaluated its possibility of clinical application to patients with malignant pleural mesothelioma (MPM). CD-DST using 26 fresh specimens obtained by biopsy or surgery on MPM patients investigated in vitro responses to cisplatin (CDDP), carboplatin (CBDCA), doxorubicin (ADR), etoposide (VP-16), 5-fluoruracil (5-FU), gemcitabine (GEM), vinorelbine (VNR), irinotecan (SN-38), and docetaxel (TXT). Correlations between CD-DST data and clinical effects were then assessed for some MPM patients undergoing chemotherapy. The rate of in vitro sensitivity to each chemoagent (N=tested number) was 35% for CDDP (N=23), 14% for CBDCA (N=21), 7% for ADR (N=15), 15% for VP-16 (N=13), 0% for 5-FU (N=15), 45% for GEM (N=11), 25% for VNR (N=8), 40% for SN-38 (N=5), and 44% for TXT (N=9). No difference was observed between CD-DST data of each chemoagent and histological type. Of these MPM patients, 14 clinical effects on 13 patients who underwent chemotherapy for primary or recurrent disease were reviewed in comparison with CD-DST data of each chemoagent. Among 10 chemotherapies including in vitro-sensitive chemoagents, 3 led to partial response (PR), and 7 resulted in four stable diseases (SDs) and 3 to progressive diseases (PDs). In contrast, among 4 chemotherapies using in vitro-resistant chemoagents, SD and PD were observed in 1 and 3, respectively. In regard to the clinical response rate, CD-DST sensitivity, specificity, and accuracy in the 14 examined chemotherapies were respectively 100%, 36%, and 50%, and in regard to the disease control rate, they were 88%, 60%, and 71%. CD-DST data for the chemoagents were to a limited extent significantly correlated with the disease control status of chemotherapy (p=0.052). Although the number of tested MPM

  10. Inversion of lithium heparin gel tubes after centrifugation is a significant source of bias in clinical chemistry testing.

    Science.gov (United States)

    Lippi, Giuseppe; Salvagno, Gian Luca; Danese, Elisa; Lima-Oliveira, Gabriel; Brocco, Giorgio; Guidi, Gian Cesare

    2014-09-25

    This study was planned to establish whether random orientation of gel tubes after centrifugation may impair sample quality. Eight gel tubes were collected from 17 volunteers: 2 Becton Dickinson (BD) serum tubes, 2 Terumo serum tubes, 2 BD lithium heparin tubes and 2 Terumo lithium heparin tubes. One patient's tube for each category was kept in a vertical, closure-up position for 90 min ("upright"), whereas paired tubes underwent bottom-up inversion every 15 min, for 90 min ("inverted"). Immediately after this period of time, 14 clinical chemistry analytes, serum indices and complete blood count were then assessed in all tubes. Significant increases were found for phosphate and lipaemic index in all inverted tubes, along with AST, calcium, cholesterol, LDH, potassium, hemolysis index, leukocytes, erythrocytes and platelets limited to lithium heparin tubes. The desirable quality specifications were exceeded for AST, LDH, and potassium in inverted lithium heparin tubes. Residual leukocytes, erythrocytes, platelets and cellular debris were also significantly increased in inverted lithium heparin tubes. Lithium heparin gel tubes should be maintained in a vertical, closure-up position after centrifugation. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Thermoresponsive Gels

    OpenAIRE

    Taylor, M. Joan; Tomlins, P.; Sahota, T. S.

    2016-01-01

    An invited review and relates to the responsive gel used in the "artificial pancreas" work og INsmart, DMU. This article is an Open Access journal. Thermoresponsive gelling materials constructed from natural and synthetic polymers can be used to provide triggered action and therefore customised products such as drug delivery and regenerative medicine types as well as for other industries. Some materials give Arrhenius-type viscosity changes based on coil to globule transitions. Others ...

  12. Thermoresponsive Gels

    Directory of Open Access Journals (Sweden)

    M. Joan Taylor

    2017-01-01

    Full Text Available Thermoresponsive gelling materials constructed from natural and synthetic polymers can be used to provide triggered action and therefore customised products such as drug delivery and regenerative medicine types as well as for other industries. Some materials give Arrhenius-type viscosity changes based on coil to globule transitions. Others produce more counterintuitive responses to temperature change because of agglomeration induced by enthalpic or entropic drivers. Extensive covalent crosslinking superimposes complexity of response and the upper and lower critical solution temperatures can translate to critical volume temperatures for these swellable but insoluble gels. Their structure and volume response confer advantages for actuation though they lack robustness. Dynamic covalent bonding has created an intermediate category where shape moulding and self-healing variants are useful for several platforms. Developing synthesis methodology—for example, Reversible Addition Fragmentation chain Transfer (RAFT and Atomic Transfer Radical Polymerisation (ATRP—provides an almost infinite range of materials that can be used for many of these gelling systems. For those that self-assemble into micelle systems that can gel, the upper and lower critical solution temperatures (UCST and LCST are analogous to those for simpler dispersible polymers. However, the tuned hydrophobic-hydrophilic balance plus the introduction of additional pH-sensitivity and, for instance, thermochromic response, open the potential for coupled mechanisms to create complex drug targeting effects at the cellular level.

  13. Yield stress determination of a physical gel

    DEFF Research Database (Denmark)

    Hvidt, Søren

    2013-01-01

    Pluronic F127 solutions form gels in water with high elastic moduli. Pluronic gels can, however, only withstand small deformations and stresses. Different steady shear and oscillatory methods traditionally used to determine yield stress values are compared. The results show that the yield stresse...... values of these gels depend on test type and measurement time, and no absolute yield stress value can be determined for these physical gels....

  14. Stratified phase II trial to establish the usefulness of the collagen gel droplet embedded culture-drug sensitivity test (CD-DST) for advanced gastric cancer.

    Science.gov (United States)

    Naitoh, Hiroyuki; Yamamoto, Hiroshi; Murata, Satoshi; Kobayashi, Hisayuki; Inoue, Katsunori; Tani, Tohru

    2014-10-01

    We conducted a multicenter phase II trial to assess the suitability of three types of chemotherapy (docetaxel plus S-1, irinotecan plus S-1, or S-1 alone) for patients with advanced gastric cancer by means of the collagen gel droplet embedded culture-drug sensitivity test (CD-DST). To our knowledge, this is the first multicenter clinical trial that has employed CD-DST to choose anticancer agents for the treatment of advanced gastric cancer. Subjects (n = 64) were patients with advanced or recurrent gastric cancer. Patients were allocated to one of the treatment regimens on the basis of CD-DST results. Outcome of the patients was compared between the groups deemed chemosensitive or chemoresistant by the CD-DST. Thirty-three patients showed high sensitivity (T/C ratio DST predicts the outcome of patients undergoing chemotherapy for advanced gastric cancer, presumably through evaluating chemosensitivity.

  15. Physical Properties of Silicone Gel Breast Implants.

    Science.gov (United States)

    Jewell, Mark L; Bengtson, Bradley P; Smither, Kate; Nuti, Gina; Perry, TracyAnn

    2018-04-28

    Surgical applications using breast implants are individualized operations to fill and shape the breast. Physical properties beyond shape, size, and surface texture are important considerations during implant selection. Compare form stability, gel material properties, and shell thickness of textured shaped, textured round, and smooth round breast implants from 4 manufacturers: Allergan, Mentor, Sientra, and Establishment Labs through bench testing. Using a mandrel height gauge, form stability was measured by retention of dimensions on device movement from a horizontal to vertical supported orientation. Dynamic response of gel material (gel cohesivity, resistance to gel deformation, energy absorption) was measured using a synchronized target laser following application of graded negative pressure. Shell thickness was measured using digital thickness gauge calipers. Form stability, gel material properties, and shell thickness differed across breast implants. Of textured shaped devices, Allergan Natrelle 410 exhibited greater form stability than Mentor MemoryShape and Sientra Shaped implants. Allergan Inspira round implants containing TruForm 3 gel had greater form stability, higher gel cohesivity, greater resistance to gel deformation, and lower energy absorption than those containing TruForm 2 gel and in turn, implants containing TruForm 1 gel. Shell thickness was greater for textured versus smooth devices, and differed across styles. Gel cohesivity, resistance to gel deformation, and energy absorption are directly related to form stability, which in turn determines shape retention. These characteristics provide information to aid surgeons choosing an implant based on surgical application, patient tissue characteristics, and desired outcome.

  16. The hen's egg chorioallantoic membrane (HET-CAM) test to predict the ophthalmic irritation potential of a cysteamine-containing gel: Quantification using Photoshop® and ImageJ.

    Science.gov (United States)

    McKenzie, Barbara; Kay, Graeme; Matthews, Kerr H; Knott, Rachel M; Cairns, Donald

    2015-07-25

    A modified hen's egg chorioallantoic membrane (HET-CAM) test has been developed, combining ImageJ analysis with Adobe(®) Photoshop(®). The irritation potential of an ophthalmic medicine can be quantified using this method, by monitoring damage to blood vessels. The evaluation of cysteamine containing hyaluronate gel is reported. The results demonstrated that the novel gel formulation is non-irritant to the ocular tissues, in line with saline solution (negative control). In conclusion, the modification of the established HET-CAM test can quantify the damage to minute blood vessels. These results offer the possibility to formulate cysteamine in an ocular applicable gel formulation. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Viscoelastic properties of soft gels: comparison of magnetic resonance elastography and dynamic shear testing in the shear wave regime

    Science.gov (United States)

    Okamoto, R. J.; Clayton, E. H.; Bayly, P. V.

    2011-10-01

    Magnetic resonance elastography (MRE) is used to quantify the viscoelastic shear modulus, G*, of human and animal tissues. Previously, values of G* determined by MRE have been compared to values from mechanical tests performed at lower frequencies. In this study, a novel dynamic shear test (DST) was used to measure G* of a tissue-mimicking material at higher frequencies for direct comparison to MRE. A closed-form solution, including inertial effects, was used to extract G* values from DST data obtained between 20 and 200 Hz. MRE was performed using cylindrical 'phantoms' of the same material in an overlapping frequency range of 100-400 Hz. Axial vibrations of a central rod caused radially propagating shear waves in the phantom. Displacement fields were fit to a viscoelastic form of Navier's equation using a total least-squares approach to obtain local estimates of G*. DST estimates of the storage G' (Re[G*]) and loss modulus G'' (Im[G*]) for the tissue-mimicking material increased with frequency from 0.86 to 0.97 kPa (20-200 Hz, n = 16), while MRE estimates of G' increased from 1.06 to 1.15 kPa (100-400 Hz, n = 6). The loss factor (Im[G*]/Re[G*]) also increased with frequency for both test methods: 0.06-0.14 (20-200 Hz, DST) and 0.11-0.23 (100-400 Hz, MRE). Close agreement between MRE and DST results at overlapping frequencies indicates that G* can be locally estimated with MRE over a wide frequency range. Low signal-to-noise ratio, long shear wavelengths and boundary effects were found to increase residual fitting error, reinforcing the use of an error metric to assess confidence in local parameter estimates obtained by MRE.

  18. Coagulase-negative staphylococci from non-mastitic bovine mammary gland: characterization of Staphylococcus chromogenes and Staphylococcus haemolyticus by antibiotic susceptibility testing and pulsed-field gel electrophoresis.

    Science.gov (United States)

    Pate, Mateja; Zdovc, Irena; Avberšek, Jana; Ocepek, Matjaž; Pengov, Andrej; Podpečan, Ožbalt

    2012-05-01

    During routine microbiological examination of milk samples from dairy cows without clinical signs of mastitis, quarter milk samples of 231 dairy cows from 12 herds were investigated for the presence of coagulase-negative staphylococci (CNS). The isolates were identified on the basis of colony morphology, Gram staining, catalase and coagulase test and the commercial kit, API Staph. CNS was detected in 29% (67/231) of the cows. A total of seven CNS species were identified with the most prevalent being Staphylococcus (Staph.) chromogenes (30%) and Staph. haemolyticus (28·8%), followed by Staph. simulans (11·2%), Staph. xylosus (11·2%), Staph. epidermidis (7·5%), Staph. hyicus (6·3%) and Staph. sciuri (5%). The predominant species, Staph. chromogenes and Staph. haemolyticus, were further characterized by antibiotic susceptibility testing using the agar disc diffusion method (Kirby-Bauer) and by pulsed-field gel electrophoresis (PFGE). Considerable resistance to ampicillin and penicillin was observed in both species. Isolates with identical or highly similar PFGE profiles were detected at the herd level despite a marked heterogeneity seen for both species. On the basis of somatic cell count, absence of clinical signs of inflammation and heterogeneity of genotypes, we assume that CNS isolated in this study could not be considered as important causative agents of the bovine mammary gland inflammation.

  19. Tunable Gas Sensing Gels by Cooperative Assembly.

    Science.gov (United States)

    Hussain, Abid; Semeano, Ana T S; Palma, Susana I C J; Pina, Ana S; Almeida, José; Medrado, Bárbara F; Pádua, Ana C C S; Carvalho, Ana L; Dionísio, Madalena; Li, Rosamaria W C; Gamboa, Hugo; Ulijn, Rein V; Gruber, Jonas; Roque, Ana C A

    2017-07-19

    The cooperative assembly of biopolymers and small molecules can yield functional materials with precisely tunable properties. Here, the fabrication, characterization, and use of multicomponent hybrid gels as selective gas sensors are reported. The gels are composed of liquid crystal droplets self-assembled in the presence of ionic liquids, which further coassemble with biopolymers to form stable matrices. Each individual component can be varied and acts cooperatively to tune gels' structure and function. The unique molecular environment in hybrid gels is explored for supramolecular recognition of volatile compounds. Gels with distinct compositions are used as optical and electrical gas sensors, yielding a combinatorial response conceptually mimicking olfactory biological systems, and tested to distinguish volatile organic compounds and to quantify ethanol in automotive fuel. The gel response is rapid, reversible, and reproducible. These robust, versatile, modular, pliant electro-optical soft materials possess new possibilities in sensing triggered by chemical and physical stimuli.

  20. Removing water from gels

    International Nuclear Information System (INIS)

    Lane, E.S.; Winter, J.A.

    1982-01-01

    Water is removed from a gel material by contacting the gel material with an organic liquid and contacting the organic liquid with a gas such that water is taken up by the gas. The invention, in one embodiment, may be used to dry gel materials whilst maintaining an open porous network therein. In one example, the invention is applied to gel precipitated spheres containing uranium and plutonium. (author)

  1. Polymer gels and networks

    National Research Council Canada - National Science Library

    Osada, Yoshihito; Khokhlov, A. R

    2002-01-01

    ... or magnetic field, etc.). It was realized that not only can polymer gels absorb and hold a considerable volume of liquids, but they can also be forced to expel the absorbed liquid in a controlled manner. Of particular interest are hydrogels, i.e., polymer gels, which swell extensively in water. The most common hydrogels are polyelectrolyte gels: ...

  2. THE DIAGNOSTIC VALUE EVALUATION OF SPECIFIC IMMUNE RESPONSE THROUGH IMMUNODIFFUSION SIMPLE RADIAL TEST (I.D.S.R.) APPLICATION IN OVINE ESTROSIS

    OpenAIRE

    DANIELA MOŢ

    2007-01-01

    Were been examined 20 blood samples from reformed sheep with ovine oestrosis.The sheep were then slaughtered and the necropsy of their heads confirms thepresence of Oestrus ovis larvae. A brut antigen was prepared from O. ovis larvaefrom I, II and III stadiums of evolution, after Bautista method (1982), with a proteiccontent of 3.84 total protein/ml serum (P.T.). The obtained results after I.D.S.R. testemphasized that O.ovis larvae induced in infected animals immunologicalreorganizations char...

  3. Differences in chemosensitivity between primary and paired metastatic lung cancer tissues: In vitro analysis based on the collagen gel droplet embedded culture drug test (CD-DST).

    Science.gov (United States)

    Higashiyama, Masahiko; Okami, Jiro; Maeda, Jun; Tokunaga, Toshiteru; Fujiwara, Ayako; Kodama, Ken; Imamura, Fumio; Kobayashi, Hisayuki

    2012-02-01

    To elucidate the differences in chemosensitivity to anticancer drugs between primary and metastatic lesions in non-small cell lung cancer (NSCLC) patients, we examined the in vitro chemosensitivities of surgically resected NSCLC tissues. A total of 32 specimens were enrolled: 26 specimens of primary lesions paired with metastases in the lymph node, 3 specimens of primary lesions paired with metastases in the adrenal gland, and 3 specimens of primary lesions paired with metastases in the lung. The collagen gel droplet embedded culture drug test (CD-DST) was applied to examine the sensitivity of the tissues to anticancer drugs, including cisplatin, gemcitabine, vinorelbine, docetaxel and 5-fluorouracil. The degree of in vitro sensitivity to each anticancer drug varied between the primary and metastatic lesions. The sensitivity of the paired metastatic lesions was significantly lower than that of the primary lesions only for gemcitabine (P=0.029), vinorelbine (P=0.012), and docetaxel (P=0.009). The incidence of cases diagnosed as CD-DST-sensitive among the paired metastatic lesions was significantly lower than that for the primary lesions for vinorelbine (P=0.035) or docetaxel (P=0.022). The difference in the sensitivity to gemcitabine between the primary and paired non-lymphatic metastases was clearer than that between the primary lesion and paired lymph node metastases. The sensitivities of the paired metastatic lesions to some anticancer drugs were significantly lower than those of the primary lesions. When performing chemotherapy based on CD-DST data using primary tumors from patients with postoperative recurrence, an appropriate regimen can be selected by carefully considering these differences.

  4. A novel chemotherapeutic sensitivity-testing system based on collagen gel droplet embedded 3D-culture methods for hepatocellular carcinoma.

    Science.gov (United States)

    Hou, Jun; Hong, Zhixian; Feng, Fan; Chai, Yantao; Zhang, Yunkai; Jiang, Qiyu; Hu, Yan; Wu, Shunquan; Wu, Yingsong; Gao, Xunian; Chen, Qiong; Wan, Yong; Bi, Jingfeng; Zhang, Zheng

    2017-11-08

    Patients suffering from advanced stage hepatocellular carcinoma (HCC) often exhibit a poor prognosis or dismal clinical outcomes due to ineffective chemotherapy or a multi-drug resistance (MDR) process. Thus, it is urgent to develop a new chemotherapeutic sensitivity testing system for HCC treatment. The presence study investigated the potential application of a novel chemotherapeutic sensitivity-testing system based on a collagen gel droplet embedded 3D-culture system (CD-DST). Primary cells were separating from surgical resection specimens and then tested by CD-DST. To identify whether HCC cell lines or cells separating from clinical specimens contain MDR features, the cells were treated with an IC 50 (half maximal inhibitory concentration) or IC max (maximal inhibitory concentration) concentration of antitumor agents, e.g., 5-furuolouracil (5-FU), paclitaxel (PAC), cisplatin (CDDP), epirubicin (EPI), or oxaliplatin (L-OHP), and the inhibitory rates (IRs) were calculated. HepG2 cells were sensitive to 5-FU, PAC, CDDP, EPI, or L-OHP; the IC 50 value is 0.83 ± 0.45 μg/ml, 0.03 ± 0.02 μg/ml, 1.15 ± 0.75 μg/ml, 0.09 ± 0.03 μg/ml, or 1.76 ± 0.44 μg/ml, respectively. Only eight (8/26), nine (9/26), or five (5/26) patients were sensitive to the IC max concentration of CDDP, EPI, or L-OHP; whereas only three (3/26), four (4/26), or two (2/26) patients were sensitive to the IC 50 concentration of CDDP, EPI, or L-OHP. No patients were sensitive to 5-FU or PAC. The in vitro drug sensitivity exanimation revealed the MDR features of HCC and examined the sensitivity of HCC cells from clinical specimens to anti-tumor agents. CD-DST may be a useful method to predict the potential clinical benefits of anticancer agents for HCC patients.

  5. Transport Phenomena in Gel

    Directory of Open Access Journals (Sweden)

    Masayuki Tokita

    2016-05-01

    Full Text Available Gel becomes an important class of soft materials since it can be seen in a wide variety of the chemical and the biological systems. The unique properties of gel arise from the structure, namely, the three-dimensional polymer network that is swollen by a huge amount of solvent. Despite the small volume fraction of the polymer network, which is usually only a few percent or less, gel shows the typical properties that belong to solids such as the elasticity. Gel is, therefore, regarded as a dilute solid because its elasticity is much smaller than that of typical solids. Because of the diluted structure, small molecules can pass along the open space of the polymer network. In addition to the viscous resistance of gel fluid, however, the substance experiences resistance due to the polymer network of gel during the transport process. It is, therefore, of importance to study the diffusion of the small molecules in gel as well as the flow of gel fluid itself through the polymer network of gel. It may be natural to assume that the effects of the resistance due to the polymer network of gel depends strongly on the network structure. Therefore, detailed study on the transport processes in and through gel may open a new insight into the relationship between the structure and the transport properties of gel. The two typical transport processes in and through gel, that is, the diffusion of small molecules due to the thermal fluctuations and the flow of gel fluid that is caused by the mechanical pressure gradient will be reviewed.

  6. Simple and practical staining of DNA with GelRed in agarose gel electrophoresis.

    Science.gov (United States)

    Huang, Qing; Baum, Larry; Fu, Wei-Ling

    2010-01-01

    Although SYBR Gold or SYBR Green I have been used in the loading buffer as a DNA stain safer than ethidium bromide for agarose gel electrophoresis, electrophoretic mobility of DNA is altered and thus DNA fragment size cannot be accurately determined. A method using GelRed in the loading buffer was developed to stain DNA fragments in agarose gel electrophoresis. Among various concentrations of GelRed, SYBR Gold, or SYBR Green I tested in the loading buffer, only the highest tested concentration of GelRed, i.e., 100x GelRed, did not change band mobility. Evaluations using various sizes of PCR products at different concentrations further confirmed that 100x GelRed could be used to accurately determine DNA fragment size. The reagent can be stored at 4 degrees C for at least 1 year without a decrease in staining sensitivity. The 100x GelRed is a sensitive and safe alternative to ethidium bromide and better than either SYBR Gold or SYBR Green I for size determination in agarose gel electrophoresis. Our laboratory now uses the GelRed method routinely with great consistency and success.

  7. Generating Palladium Nanoclusters Inside Very Lipophilic Gel-Type Functional Resins: Preliminary Catalytic Tests in the Hydrogenation of 2-Ethyl-Anthraquinone to 2-Ethylanthrahydroquinone

    Czech Academy of Sciences Publication Activity Database

    Bombi, G.; Lora, S.; Zancato, M.; D'Archivio, A. A.; Jeřábek, Karel; Corain, B.

    2003-01-01

    Roč. 194, 1-2 (2003), s. 273-281 ISSN 1381-1169 Institutional research plan: CEZ:AV0Z4072921 Keywords : palladium nanoclusters * gel-type resins * catalyst Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.264, year: 2003

  8. Initial investigation of a novel light-scattering gel phantom for evaluation of optical CT scanners for radiotherapy gel dosimetry

    International Nuclear Information System (INIS)

    Bosi, Stephen; Naseri, Pourandokht; Puran, Alicia; Davies, Justin; Baldock, Clive

    2007-01-01

    There is a need for stable gel materials for phantoms used to validate optical computerized tomography (CT) scanners used in conjunction with radiation-induced polymerizing gel dosimeters. Phantoms based on addition of light-absorbing dyes to gelatine to simulate gel dosimeters have been employed. However, to more accurately simulate polymerizing gels one requires phantoms that employ light-scattering colloidal suspensions added to the gel. In this paper, we present the initial results of using an optical CT scanner to evaluate a novel phantom in which radiation-exposed polymer gels are simulated by the addition of colloidal suspensions of varying turbidity. The phantom may be useful as a calibration transfer standard for polymer gel dosimeters. The tests reveal some phenomena peculiar to light-scattering gels that need to be taken into account when calibrating polymer gel dosimeters

  9. Sol-Gel Glasses

    Science.gov (United States)

    Mukherjee, S. P.

    1985-01-01

    Multicomponent homogeneous, ultrapure noncrystalline gels/gel derived glasses are promising batch materials for the containerless glass melting experiments in microgravity. Hence, ultrapure, homogeneous gel precursors could be used to: (1) investigate the effect of the container induced nucleation on the glass forming ability of marginally glass forming compositions; and (2) investigate the influence of gravity on the phase separation and coarsening behavior of gel derived glasses in the liquid-liquid immiscibility zone of the nonsilicate systems having a high density phase. The structure and crystallization behavior of gels in the SiO2-GeO2 as a function of gel chemistry and thermal treatment were investigated. As are the chemical principles involved in the distribution of a second network former in silica gel matrix being investigated. The procedures for synthesizing noncrystalline gels/gel-monoliths in the SiO2-GeO2, GeO2-PbO systems were developed. Preliminary investigations on the levitation and thermal treatment of germania silicate gel-monoliths in the Pressure Facility Acoustic Levitator were done.

  10. Cumulative irritation comparison of adapalene gel and solution with 2 tazarotene gels and 3 tretinoin formulations.

    Science.gov (United States)

    Greenspan, Alan; Loesche, Christian; Vendetti, Nancy; Georgeian, Kathleen; Gilbert, Richard; Poncet, Michel; Baker, Michael D; Soto, Pascale

    2003-07-01

    Forty-two subjects with normal skin were enrolled in a single-center study to assess the cumulative irritancy potential of adapalene (Differin gel 0.1% and Differin solution 0.1%) compared with tazarotene (Tazorac gels 0.05% and 0.1%), tretinoin (Retin-A Micro gel 0.1%, Avita cream 0.025%, and Avita gel 0.025%), and white petrolatum (negative control). All test materials were applied randomly, under occlusion, to sites located on either side of the midline--the mid thoracic area of the subjects' backs. All patches were applied daily, Monday through Friday, to the same sites, unless the degree of reaction to a test product or adhesive necessitated removal (grade 3). Thirty-eight of the 42 subjects (90.5%) completed the study. Thirty-four of those 38 subjects (89.5%) had to discontinue using both tazarotene concentrations due to intolerance. Patch discontinuations for the remaining test materials were as follows: 7 subjects discontinued use of tretinoin microsphere gel 0.1%, 3 discontinued tretinoin cream 0.025%, 1 discontinued tretinoin gel 0.025%, and 1 discontinued adapalene gel 0.1%. None of the subjects discontinued use of the white petrolatum or the adapalene solution 0.1%. Adapalene gel and solution 0.1% were statistically (P<.01) less irritating than both tazarotene gels 0.1% and 0.05%, tretinoin microsphere gel 0.1%, and tretinoin gel 0.025%, and they were not statistically different from tretinoin gel 0.025%.

  11. GelTouch

    DEFF Research Database (Denmark)

    Miruchna, Viktor; Walter, Robert; Lindlbauer, David

    2015-01-01

    We present GelTouch, a gel-based layer that can selectively transition between soft and stiff to provide tactile multi-touch feedback. It is flexible, transparent when not activated, and contains no mechanical, electromagnetic, or hydraulic components, resulting in a compact form factor (a 2mm thin...... touchscreen layer for our prototype). The activated areas can be morphed freely and continuously, without being limited to fixed, predefined shapes. GelTouch consists of a poly(N-isopropylacrylamide) gel layer which alters its viscoelasticity when activated by applying heat (>32 C). We present three different...

  12. Transport Phenomena in Gel

    OpenAIRE

    Masayuki Tokita

    2016-01-01

    Gel becomes an important class of soft materials since it can be seen in a wide variety of the chemical and the biological systems. The unique properties of gel arise from the structure, namely, the three-dimensional polymer network that is swollen by a huge amount of solvent. Despite the small volume fraction of the polymer network, which is usually only a few percent or less, gel shows the typical properties that belong to solids such as the elasticity. Gel is, therefore, regarded as a dilu...

  13. On shear rheology of gel propellants

    Energy Technology Data Exchange (ETDEWEB)

    Rahimi, Shai; Peretz, Arie [RAFAEL, MANOR Propulsion and Explosive Systems Division, Haifa (Israel); Natan, Benveniste [Faculty of Aerospace Engineering, Technion - Israel Institute of Technology, Haifa (Israel)

    2007-04-15

    Selected fuel, oxidizer and simulant gels were prepared and rheologically characterized using a rotational rheometer. For fuel gelation both organic and inorganic gellants were utilized, whereas oxidizers and simulants were gelled with addition of silica and polysaccharides, respectively. The generalized Herschel-Bulkley constitutive model was found to most adequately represent the gels studied. Hydrazine-based fuels, gelled with polysaccharides, were characterized as shear-thinning pseudoplastic fluids with low shear yield stress, whereas inhibited red-fuming nitric acid (IRFNA) and hydrogen peroxide oxidizers, gelled with silica, were characterized as yield thixotropic fluids with significant shear yield stress. Creep tests were conducted on two rheological types of gels with different gellant content and the results were fitted by Burgers-Kelvin viscoelastic constitutive model. The effect of temperature on the rheological properties of gel propellant simulants was also investigated. A general rheological classification of gel propellants and simulants is proposed. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  14. Cyanocobalamin Nasal Gel

    Science.gov (United States)

    ... to supply extra vitamin B12 to people who need unusually large amounts of this vitamin because they are pregnant or have certain diseases. ... Cyanocobalamin nasal gel will supply you with enough vitamin B12 only as ... it regularly. You may need to use cyanocobalamin nasal gel every week for ...

  15. Modeling chemoresponsive polymer gels.

    Science.gov (United States)

    Kuksenok, Olga; Deb, Debabrata; Dayal, Pratyush; Balazs, Anna C

    2014-01-01

    Stimuli-responsive gels are vital components in the next generation of smart devices, which can sense and dynamically respond to changes in the local environment and thereby exhibit more autonomous functionality. We describe recently developed computational methods for simulating the properties of such stimuli-responsive gels in the presence of optical, chemical, and thermal gradients. Using these models, we determine how to harness light to drive shape changes and directed motion in spirobenzopyran-containing gels. Focusing on oscillating gels undergoing the Belousov-Zhabotinksy reaction, we demonstrate that these materials can spontaneously form self-rotating assemblies, or pinwheels. Finally, we model temperature-sensitive gels that encompass chemically reactive filaments to optimize the performance of this system as a homeostatic device for regulating temperature. These studies could facilitate the development of soft robots that autonomously interconvert chemical and mechanical energy and thus perform vital functions without the continuous need of external power sources.

  16. Pulsed field gel electrophoresis a practical guide

    CERN Document Server

    Birren, Bruce

    1993-01-01

    Pulsed Field Gel Electrophoresis: A Practical Guide is the first laboratory manual to describe the theory and practice of this technique. Based on the authors' experience developing pulsed field gel instruments and teaching procedures, this book provides everything a researcher or student needs to know in order to understand and carry out pulsed field gel experiments. Clear, well-tested protocols assume only that users have a basic familiarity with molecular biology. Thorough coverage of useful data, theory, and applications ensures that this book is also a lasting resource for more adv

  17. Preliminary study of an immunochromatography test for serological diagnosis of canine brucellosis.

    Science.gov (United States)

    Wanke, M M; Cairó, F; Rossano, M; Laiño, M; Baldi, P C; Monachesi, N E; Comercio, E A; Vivot, M M

    2012-12-01

    The most widely used screening test for the diagnosis of brucellosis in the dog is the rapid slide agglutination test in the presence of 2-mercaptoethanol (2ME-RSAT). The diagnosis is partially confirmed by the agar gel immunodiffusion test (AGID) and definitively confirmed by bacteriological isolation. Some chronic cases not detected by these tests may be detected by ELISA tests. The use of 2ME-RSAT in routine clinical practice requires a microscope and an experienced operator. An immunochromatographic diagnostic test for canine brucellosis (FASTest(®) Brucella c., Megacor, Hörbranz, Austria) has been recently released. In this study, we compared the diagnostic performance of the FASTest with those of 2ME-RSAT, AGID and ELISAs. Sera from 17 healthy dogs used as negative controls yielded negative results by FASTest, indicating a 100% specificity in this sample. Among 27 sera of dogs with acute or subacute brucellosis confirmed by B. canis isolation, all of which were positive by RSAT and ELISAs, the FASTest was positive in 24 cases and AGID in 23. In acute and subacute cases, the sensitivity of FASTest was 89%. Sera from six dogs with bacteriologically confirmed chronic brucellosis, which were positive by ELISAs but negative by 2ME-RSAT, were also tested; 1 was positive by FASTest and 4 were positive by AGID. These preliminary results indicate a good specificity of the FASTest (100% in this sample) but an unacceptable sensitivity as a screening test. In cases with chronic brucellosis, the sensitivity of the FASTest was lower than that of ELISAs but this assay could make a good intermediate test to be run after a positive RSAT and before running an AGID. © 2012 Blackwell Verlag GmbH.

  18. Sol-gel bonding of silicon wafers

    International Nuclear Information System (INIS)

    Barbe, C.J.; Cassidy, D.J.; Triani, G.; Latella, B.A.; Mitchell, D.R.G.; Finnie, K.S.; Short, K.; Bartlett, J.R.; Woolfrey, J.L.; Collins, G.A.

    2005-01-01

    Sol-gel bonds have been produced between smooth, clean silicon substrates by spin-coating solutions containing partially hydrolysed silicon alkoxides. The two coated substrates were assembled and the resulting sandwich fired at temperatures ranging from 60 to 600 deg. C. The sol-gel coatings were characterised using attenuated total reflectance Fourier transform infrared spectroscopy, ellipsometry, and atomic force microscopy, while the corresponding bonded specimens were investigated using scanning electron microscopy and cross-sectional transmission electron microscopy. Mechanical properties were characterised using both microindentation and tensile testing. Bonding of silicon wafers has been successfully achieved at temperatures as low as 60 deg. C. At 300 deg. C, the interfacial fracture energy was 1.55 J/m 2 . At 600 deg. C, sol-gel bonding provided superior interfacial fracture energy over classical hydrophilic bonding (3.4 J/m 2 vs. 1.5 J/m 2 ). The increase in the interfacial fracture energy is related to the increase in film density due to the sintering of the sol-gel interface with increasing temperature. The superior interfacial fracture energy obtained by sol-gel bonding at low temperature is due to the formation of an interfacial layer, which chemically bonds the two sol-gel coatings on each wafer. Application of a tensile stress on the resulting bond leads to fracture of the samples at the silicon/sol-gel interface

  19. SU-F-BRA-11: An Experimental Commissioning Test of Brachytherapy MBDCA Dosimetry, Based On a Commercial Radiochromic Gel/optical CT System

    Energy Technology Data Exchange (ETDEWEB)

    Pappas, E; Karaiskos, P; Zourari, K; Peppa, V; Papagiannis, P [Medical Physics Laboratory, Medical School, University of Athens (Greece)

    2015-06-15

    Purpose: To implement a 3D dose verification procedure of Model-Based Dose Calculation Algorithms (MBDCAs) for {sup 192}Ir HDR brachytherapy, based on a novel Ferrous Xylenol-orange gel (FXG) and optical CT read-out. Methods: The TruView gel was employed for absolute dosimetry in conjunction with cone-beam optical CT read-out with the VISTA scanner (both from Modus Medical Inc, London, ON, Canada). A multi-catheter skin flap was attached to a cylindrical PETE jar (d=9.6cm, h=16cm) filled with FXG, which served as both the dosimeter and the water equivalent phantom of bounded dimensions. X- ray CT image series of the jar with flap attached was imported to Oncentra Brachy v.4.5. A treatment plan consisting of 8 catheters and 56 dwell positions was generated, and Oncentra-ACE MBDCA as well as TG43 dose results were exported for further evaluation. The irradiation was carried out with a microSelecton v2 source. The FXG dose-response, measured via an electron irradiation of a second dosimeter from the same batch, was linear (R2>0.999) at least up to 12Gy. A MCNP6 input file was prepared from the DICOM-RT plan data using BrachyGuide to facilitate Monte Carlo (MC) simulation dosimetry in the actual experimental geometry. Agreement between experimental (reference) and calculated dose distributions was evaluated using the 3D gamma index (GI) method with criteria (5%-2mm applied locally) determined from uncertainty analysis. Results: The TG-43 GI failed, as expected, in the majority of voxels away from the flap (pass rate 59% for D>0.8Gy, corresponding to 10% of prescribed dose). ACE performed significantly better (corresponding pass rate 92%). The GI evaluation for the MC data (corresponding pass rate 97%) failed mainly at low dose points of increased uncertainty. Conclusion: FXG gel/optical CT is an efficient method for level-2 commissioning of brachytherapy MBDCAs. Target dosimetry is not affected from uncertainty introduced by TG43 assumptions in 192Ir skin brachytherapy

  20. SU-F-BRA-11: An Experimental Commissioning Test of Brachytherapy MBDCA Dosimetry, Based On a Commercial Radiochromic Gel/optical CT System

    International Nuclear Information System (INIS)

    Pappas, E; Karaiskos, P; Zourari, K; Peppa, V; Papagiannis, P

    2015-01-01

    Purpose: To implement a 3D dose verification procedure of Model-Based Dose Calculation Algorithms (MBDCAs) for 192 Ir HDR brachytherapy, based on a novel Ferrous Xylenol-orange gel (FXG) and optical CT read-out. Methods: The TruView gel was employed for absolute dosimetry in conjunction with cone-beam optical CT read-out with the VISTA scanner (both from Modus Medical Inc, London, ON, Canada). A multi-catheter skin flap was attached to a cylindrical PETE jar (d=9.6cm, h=16cm) filled with FXG, which served as both the dosimeter and the water equivalent phantom of bounded dimensions. X- ray CT image series of the jar with flap attached was imported to Oncentra Brachy v.4.5. A treatment plan consisting of 8 catheters and 56 dwell positions was generated, and Oncentra-ACE MBDCA as well as TG43 dose results were exported for further evaluation. The irradiation was carried out with a microSelecton v2 source. The FXG dose-response, measured via an electron irradiation of a second dosimeter from the same batch, was linear (R2>0.999) at least up to 12Gy. A MCNP6 input file was prepared from the DICOM-RT plan data using BrachyGuide to facilitate Monte Carlo (MC) simulation dosimetry in the actual experimental geometry. Agreement between experimental (reference) and calculated dose distributions was evaluated using the 3D gamma index (GI) method with criteria (5%-2mm applied locally) determined from uncertainty analysis. Results: The TG-43 GI failed, as expected, in the majority of voxels away from the flap (pass rate 59% for D>0.8Gy, corresponding to 10% of prescribed dose). ACE performed significantly better (corresponding pass rate 92%). The GI evaluation for the MC data (corresponding pass rate 97%) failed mainly at low dose points of increased uncertainty. Conclusion: FXG gel/optical CT is an efficient method for level-2 commissioning of brachytherapy MBDCAs. Target dosimetry is not affected from uncertainty introduced by TG43 assumptions in 192Ir skin brachytherapy

  1. Periodic mesoporous silica gels

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, M.T.; Martin, J.E.; Odinek, J.G. [and others

    1996-06-01

    We have synthesized monolithic particulate gels of periodic mesoporous silica by adding tetramethoxysilane to a homogeneous alkaline micellar precursor solution. The gels exhibit 5 characteristic length scales over 4 orders of magnitude: fractal domains larger than the particle size (>500 nm), particles that are {approximately}150 to 500 nm in diameter, interparticle pores that are on the order of the particle size, a feature in the gas adsorption measurements that indicates pores {approximately}10-50 nm, and periodic hexagonal arrays of {approximately}3 nm channels within each particle. The wet gel monoliths exhibit calculated densities as low as {approximately}0.02 g/cc; the dried and calcined gels have bulk densities that range from {approximately}0.3-0.5 g/cc. The materials possess large interparticle ({approximately}1.0-2.3 cc/g) and intraparticle ({approximately}0.6 cc/g) porosities.

  2. Immunochromatographic lateral flow test for detection of antibodies to Equine infectious anemia virus.

    Science.gov (United States)

    Alvarez, I; Gutierrez, G; Barrandeguy, M; Trono, K

    2010-08-01

    The purpose of this study was to develop and evaluate a simple immunochromatographic lateral flow (ICLF) test for specific detection of Equine infectious anemia virus (EIAV) antibodies in equine sera. Viral recombinant p26 capsid protein (rp26) was used as the capture protein in the test line and as the detector reagent conjugated to colloidal gold. The performance of rp26-ICLF was evaluated, and the results obtained were compared with a commercially available agar gel immunodiffusion (AGID) test used as a standard of comparison according to international guidelines. The values obtained for comparative diagnostic sensitivity (98.3%), diagnostic specificity (87.4%) and concordance (92.4%) were similar to those reported for other ICLF tests for animal infectious diseases. Very good repeatability and reproducibility, as well as a total agreement with blind previous results from three proficiency test panels, were obtained, thus indicating that rp26-ICLF is a precise test. The end point of the twofold serial dilution of serum samples was the same as, and even better than, the AGID test, thus demonstrating the same analytical sensitivity as that of the reference method for EIA diagnosis. No cross-reactivity was observed when serum samples from horses with other infectious diseases were analyzed. rp26-ICLF proved to be a precise and rapid test suitable for field screening in veterinary practice, since minimal equipment and operator expertise are required. However, further research should be carried out to increase the level of sensitivity. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  3. Improving calibration accuracy in gel dosimetry

    International Nuclear Information System (INIS)

    Oldham, M.; McJury, M.; Webb, S.; Baustert, I.B.; Leach, M.O.

    1998-01-01

    A new method of calibrating gel dosimeters (applicable to both Fricke and polyacrylamide gels) is presented which has intrinsically higher accuracy than current methods, and requires less gel. Two test-tubes of gel (inner diameter 2.5 cm, length 20 cm) are irradiated separately with a 10x10cm 2 field end-on in a water bath, such that the characteristic depth-dose curve is recorded in the gel. The calibration is then determined by fitting the depth-dose measured in water, against the measured change in relaxivity with depth in the gel. Increased accuracy is achieved in this simple depth-dose geometry by averaging the relaxivity at each depth. A large number of calibration data points, each with relatively high accuracy, are obtained. Calibration data over the full range of dose (1.6-10 Gy) is obtained by irradiating one test-tube to 10 Gy at dose maximum (D max ), and the other to 4.5 Gy at D max . The new calibration method is compared with a 'standard method' where five identical test-tubes of gel were irradiated to different known doses between 2 and 10 Gy. The percentage uncertainties in the slope and intercept of the calibration fit are found to be lower with the new method by a factor of about 4 and 10 respectively, when compared with the standard method and with published values. The gel was found to respond linearly within the error bars up to doses of 7 Gy, with a slope of 0.233±0.001 s -1 Gy -1 and an intercept of 1.106±0.005 Gy. For higher doses, nonlinear behaviour was observed. (author)

  4. Gel purification of RNA.

    Science.gov (United States)

    Nilsen, Timothy W

    2013-02-01

    For many applications, including size selection of RNAs and purification of in vitro transcription products, it is necessary to purify RNAs on a denaturing gel. This procedure describes how to purify transcripts that have been synthesized in vitro. It is useful for labeled or unlabeled RNAs when sufficient mass is present. It can also be used to isolate small RNAs. In general, RNA purification by denaturing gel electrophoresis is practical only when the size of the desired RNA is 600 nucleotides or less.

  5. Conformance Improvement Using Gels

    Energy Technology Data Exchange (ETDEWEB)

    Seright, Randall S.; Schrader, Richard; II Hagstrom, John; Wang, Ying; Al-Dahfeeri, Abdullah; Gary, Raven; Marin; Amaury; Lindquist, Brent

    2002-09-26

    This research project had two objectives. The first objective was to identify gel compositions and conditions that substantially reduce flow through fractures that allow direct channeling between wells, while leaving secondary fractures open so that high fluid injection and production rates can be maintained. The second objective was to optimize treatments in fractured production wells, where the gel must reduce permeability to water much more than that to oil.

  6. Pilot test of biological removal of 1,4-dioxane from a chemical factory wastewater by gel carrier entrapping Afipia sp. strain D1

    International Nuclear Information System (INIS)

    Isaka, Kazuichi; Udagawa, Makiko; Sei, Kazunari; Ike, Michihiko

    2016-01-01

    Highlights: • Two pilot-scale biological 1,4-dioxane (1,4-D) treatment systems were operated. • Gel cubes entrapping Afipia sp. strain D1 were used for real wastewater treatment. • The maximum 1,4-dioxane removal rates of 0.72 kg m −3 day −1 was observed. • Monod model describes 1,4-D degradation, showing half saturation constant is 28 mg L −1 . - Abstract: A pilot-scale (120 L) bioreactor system using a gel carrier-entrapped pure bacterial strain, Afipia sp. strain D1, capable of degrading 1,4-dioxane as a sole carbon and energy source was constructed and applied to treat real industrial wastewater containing 1,4-dioxane from a chemical factory. Although the wastewater not only contained high concentrations of 1,4-dioxane but also considerable amounts of other organic compounds (73 mg-TOC L −1 on average), the bioreactor could efficiently remove 1,4-dioxane without significant inhibitory effects. The reactor startup could be completed within approximately 1 month by increasing the 1,4-dioxane loading rate (0.09–0.47 kg-dioxane m −3 d −1 ) in a stepwise manner. Effective 1,4-dioxane removal was stably maintained for 3 months with an influent 1,4-dioxane of 570–730 mg L −1 , giving an average effluent concentration and removal rate of 3.4 mg L −1 and 0.46 kg-dioxane m −3 d −1 , respectively. A 1,4-dioxane loading fluctuation between 0.14 and 0.72 kg-dioxane m −3 d −1 did not significantly affect its removal, and more than 99% removal efficiency was constantly maintained. The Monod model could well describe the relationship between the effluent 1,4-dioxane concentration and 1,4-dioxane removal rates of the bioreactors, showing that the half-saturation constant (Ks) was 28 mg L −1 .

  7. Pilot test of biological removal of 1,4-dioxane from a chemical factory wastewater by gel carrier entrapping Afipia sp. strain D1

    Energy Technology Data Exchange (ETDEWEB)

    Isaka, Kazuichi, E-mail: kazuichi.isaka.mp@hitachi.com [Matsudo Research Center, Infrastructure System Company, Hitachi, Ltd., 537 Kami-hongo, Matsudo, Chiba 271-0064 (Japan); Udagawa, Makiko [Matsudo Research Center, Infrastructure System Company, Hitachi, Ltd., 537 Kami-hongo, Matsudo, Chiba 271-0064 (Japan); Sei, Kazunari, E-mail: ksei@kitasato-u.ac.jp [Division of Sustainable Energy and Environmental Engineering, Osaka University, Yamadaoka, 2-1, Suita, Osaka 565-0871 (Japan); Department of Health Science, School of Allied Health Sciences, Kitasato University, 1-15-1 Kitasato, Sagamihara-Minami, Kanagawa 252-0373 (Japan); Ike, Michihiko, E-mail: ike@see.eng.osaka-u.ac.jp [Division of Sustainable Energy and Environmental Engineering, Osaka University, Yamadaoka, 2-1, Suita, Osaka 565-0871 (Japan)

    2016-03-05

    Highlights: • Two pilot-scale biological 1,4-dioxane (1,4-D) treatment systems were operated. • Gel cubes entrapping Afipia sp. strain D1 were used for real wastewater treatment. • The maximum 1,4-dioxane removal rates of 0.72 kg m{sup −3} day{sup −1} was observed. • Monod model describes 1,4-D degradation, showing half saturation constant is 28 mg L{sup −1}. - Abstract: A pilot-scale (120 L) bioreactor system using a gel carrier-entrapped pure bacterial strain, Afipia sp. strain D1, capable of degrading 1,4-dioxane as a sole carbon and energy source was constructed and applied to treat real industrial wastewater containing 1,4-dioxane from a chemical factory. Although the wastewater not only contained high concentrations of 1,4-dioxane but also considerable amounts of other organic compounds (73 mg-TOC L{sup −1} on average), the bioreactor could efficiently remove 1,4-dioxane without significant inhibitory effects. The reactor startup could be completed within approximately 1 month by increasing the 1,4-dioxane loading rate (0.09–0.47 kg-dioxane m{sup −3} d{sup −1}) in a stepwise manner. Effective 1,4-dioxane removal was stably maintained for 3 months with an influent 1,4-dioxane of 570–730 mg L{sup −1}, giving an average effluent concentration and removal rate of 3.4 mg L{sup −1} and 0.46 kg-dioxane m{sup −3} d{sup −1}, respectively. A 1,4-dioxane loading fluctuation between 0.14 and 0.72 kg-dioxane m{sup −3} d{sup −1} did not significantly affect its removal, and more than 99% removal efficiency was constantly maintained. The Monod model could well describe the relationship between the effluent 1,4-dioxane concentration and 1,4-dioxane removal rates of the bioreactors, showing that the half-saturation constant (Ks) was 28 mg L{sup −1}.

  8. Gel-eletroforese no diagnóstico da varíola Gel-electrophoresis in the smallpox diagnosis

    Directory of Open Access Journals (Sweden)

    Julio A. Mesquita

    1972-01-01

    Full Text Available O emprego de gel-eletroforese no diagnóstico da varíola, demonstrou ser ao menos trinta vezes (30X mais sensível que o teste de agar-gel, nas condições descritas (tabela I. Doze (12 espécimes, cujos testes convencionais de inoculação em ovos embrionados e de agar-gel resultaram positivos, foram testados em suas diluições originais congeladas por mais de um ano, sendo seis deles revelados por gel-eletroforese enquanto nenhum o foi por agar-gel (tabela II. Trinta e três (33 amostras isoladas no laboratório, foram testadas com material colhido de membrana cório-alantóica da primeira inoculação para o diagnóstico, conservado em glicerina 50%, resultando 15 positivas em gel-eletroforese e apenas 3 em agar-gel (tabela II. Os últimos 60 espécimes recebidos para diagnóstico, através a Campanha de Erradicação da Varíola, também resultaram negativos em gel-eletroforese, que não mostrou falsos-positivos nas condições descritas.The test of gel-electrophoresis applied to the pox virus group showed to be at least thirth times (30X more sensitive than agar-gel test on the described conditions (Table I. Twelve specimens, which were positives form Smallpox in the conventional tests of egg inoculation and agar-gel difusion test, have been screened in their original dilutions frozen for more than 1 year and six of them were still detectable by gel-eletrophoresis, while by agar-gel test any of them was positive (Table II. Thirty three Smallpox isolates have been tested with material from first egg inoculation (chorioallantoic membranes which have been stored in glycerin 50%, at - 15ºC. Fifteen of them were still positive by gel-electrophoresis and only 3 by agar-gel (Table II. The last 60 specimens received for diagnosis from Smallpox Erradication Campaign (CEV, were negatives by both tests. The gel-electrophoresis, did not show false-positives on described conditions.

  9. Use of arbitrary DNA primers, polyacrylamide gel electrophoresis and silver staining for identity testing, gene discovery and analysis of gene expression

    International Nuclear Information System (INIS)

    Gresshoff, P.

    1998-01-01

    To understand chemically-induced genomic differences in soybean mutants differing in their ability to enter the nitrogen-fixing symbiosis involving Bradyrhizobium japonicum, molecular techniques were developed to aid the map-based, or positional, cloning. DNA marker technology involving single arbitrary primers was used to enrich regional RFLP linkage data. Molecular techniques, including two-dimensional pulse field gel electrophoresis, were developed to ascertain the first physical mapping in soybean, leading to the conclusion that in the region of marker pA-36 on linkage group H, 1 cM equals about 500 cM. High molecular weight DNA was isolated and cloned into yeast or bacterial artificial chromosomes (YACs/ BACs). YACs were used to analyze soybean genome structure, revealing that over half of the genome contains repetitive DNA. Genetic and molecular tools are now available to facilitate the isolation of plant genes directly involved in symbiosis. The further characterization of these genes, along with the determination of the mechanisms that lead to the mutation, will be of value to other plants and induced mutation research. (author)

  10. LABORATORY TESTS ON INSECTICIDAL EFFECTIVENESS OF DISODIUM OCTABORATE TETRAHYDRATE, DIATOMACEOUS EARTH AND AMORPHOUS SILICA GEL AGAINST Sitophilus oryzae (L. AND THEIR EFFECT ON WHEAT BULK DENSITY

    Directory of Open Access Journals (Sweden)

    Zlatko Korunić

    2017-01-01

    Full Text Available We examined insecticide effectiveness of three different inert dusts: disodium octaborate tetrahydrate (DOT and diatomaceous earth (DE Celatom® Mn 51 applied as powder and suspension, and silica gel Sipernat® 50 S applied as powder against Sitophilus oryzae (L. and their reduction of grain bulk density. Sipernat® 50 S was the most effective dust with a very fast initial effectiveness. DE and DOT generated similar effectiveness against S. oryzae. DOT generated low initial effectiveness but after prolonged exposure time of 8 and especially after 21 days, the mortality was very high (100%, similar to the effectiveness of DE. The similar order of dusts was obtained in the reduction of wheat bulk density. Applied at dose of 200 and 500 ppm, the lowest bulk density difference in regard to bulk density of untreated wheat had DOT (-1.1 and -1.9 kg hl-1, respectively, followed by Celatom® Mn 51 (-3.5 and -4.3 kg hl-1, respectively and Sipernat® 50 S (-5.2 and -5.5 kg hl-1, respectively. Due to the effect on wheat bulk density DOT belongs to the group with the least negative effect on bulk density and therefore, it is a promising dust to control stored grain insect pests.

  11. Active Polymer Gel Actuators

    Directory of Open Access Journals (Sweden)

    Shuji Hashimoto

    2010-01-01

    Full Text Available Many kinds of stimuli-responsive polymer and gels have been developed and applied to biomimetic actuators or artificial muscles. Electroactive polymers that change shape when stimulated electrically seem to be particularly promising. In all cases, however, the mechanical motion is driven by external stimuli, for example, reversing the direction of electric field. On the other hand, many living organisms can generate an autonomous motion without external driving stimuli like self-beating of heart muscles. Here we show a novel biomimetic gel actuator that can walk spontaneously with a wormlike motion without switching of external stimuli. The self-oscillating motion is produced by dissipating chemical energy of oscillating reaction. Although the gel is completely composed of synthetic polymer, it shows autonomous motion as if it were alive.

  12. Ação do fungo Beauveria bassiana associado a gel polimerizado de celulose no controle do carrapato Anocentor nitens em teste de campo Action of the fungus Beauveria bassiana associated with cellulose polymerized gel in the control of the tick Anocentor nitens in a field test

    Directory of Open Access Journals (Sweden)

    E.J. Souza

    2009-02-01

    Full Text Available Foram selecionados 20 equídeos naturalmente infestados por Anocentor nitens, dos quais seus pavilhões auriculares foram submetidos a quatro tratamentos distintos: gel associado a Beauveria bassiana, apenas gel, apenas B. bassiana e um grupo-controle. Procederam-se à contagem e ao registro do número total de fêmeas adultas (>3mm em cada pavilhão auricular, nos dias 0, 1, 4, 7, 11, 14, 18, 21, 25 e 28, para cálculo do percentual de controle. Foram coletadas e mantidas em laboratório 20 fêmeas pertencentes a cada tratamento, para cálculo dos períodos de pré-postura, postura, incubação e eclosão, e peso médio das posturas. No grupo tratado com o composto gel associado a B. bassiana, observou-se percentual de controle maior que 50%, entre o 4º e o 25º dia, assim como decréscimo progressivo do peso médio da postura das fêmeas coletadas no período entre o 7º e 14º dia. Para os outros tratamentos, o percentual de controle manteve-se abaixo de 20%, e o peso da postura não apresentou diferença significativa. Os percentuais de controle, assim como as reduções no peso médio da postura, sugerem que a utilização do composto gel associado a B. bassiana potencializou a virulência do entomopatógeno.Twenty horses naturally infected by Anocentor nitens were selected and their auricular pinna were submitted to four treatments: gel associated with Beauveria bassiana, gel only, B. bassiana only, and a control group. The count and the register of the total number of grown up tick females (>3mm were performed in each auricular pinna on days 0, 1, 4, 7, 11, 14, 18, 21, 25, and 28 for the calculus of percentage of control. Twenty females from each treatment were collected and maintained in laboratory, to calculate the periods of pre-oviposition, oviposition, incubation, and hatching and mean weight of oviposition. In the group treated with the gel associated to B. bassiana, it was observed a control percentage higher than 50% from the 4º

  13. Intrathecal Delivery of Ketorolac Loaded In Situ Gels for Prolonged ...

    African Journals Online (AJOL)

    Further, KT-loaded gels exhibited viscosity in the range of 1.11 to 6 cps at 50 rpm and shear thinning property (rheology testing). Additionally, the gels demonstrated 84.43 to 96.98 % drug release at the end of 12 h. In particular, in situ gels prepared from 1.2 % alginate/0.4 % HPMC (G7) exhibited excellent analgesic (54.28 ...

  14. 3D MR gel dosimetry with lung equivalent gel; 3D MR-Gel-Dosimetrie mit lungenaequivalentem Gel

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, J.; Solleder, M.; Schiessl, I.; Bogner, L.; Herbst, M. [Klinik und Poliklinik fuer Strahlentherapie und Radioonkologie, Regensburg Univ. (Germany)

    1998-12-31

    The MR gel dosimetry is used to verify complex 3D treatment plans. Till now this method served only for dose evaluation in homogeneous phantoms. On the way to build a heterogeneous anthropomorphic gel phantom, a lung equivalent gel with the density 0.4 g/cm{sup 3} was developed. First experiments show a 1.55 times higher dose reponse in the low density gel (LD gel). The comparison of a dose distribution in a gel/LD gel/gel slab phantom with Monte Carlo calculations shows good agreement within 5%. More over the accuray of the measuring device magnetic resonance imager was studied in respect to the now exclusive digital image processing with the software MRD (MR dosimetry). Because of the dimensions of the Fricke gel phantom an artefact correction, based on the data from the unirradiated phantom proved to be essential. (orig.) [Deutsch] Die MR-Gel-Dosimetrie zur Verifikation komplexer 3D-Bestrahlungsplaene wurde bislang ausschliesslich in homogenen Phantomen durchgefuehrt. Auf dem Wege zum Bau eines inhomogenen Humanoid-Gel-Phantoms wurde ein lungenaequivalentes Gel mit der Dichte 0,4 g/cm{sup 3} entwickelt. Erste Messungen zeigen ein um den Faktor 1,55 hoeheres Ansprechvermoegen in dem low-density-Gel (LD-Gel). Der Vergleich einer gemessen Dosisverteilung in einem Gel/LD-Gel/Gel Schichtphantom als einfaches Thoraxmodell mit Monte-Carlo-Rechnungen zeigt eine gute Uebereinstimmung innerhalb 5%. Ausserdem wurden Untersuchungen zur Messgenauigkeit des Kernspintomographen im Rahmen der nun ausschliesslich digitalen Auswertung mit Hilfe des Programms MRD (MR-Dosimetrie) durchgefuehrt. Es zeigt sich, dass eine Artefaktkorrektur auf der Basis einer Messung des unbestrahlten Phantoms bei grossen Fricke-Gel-Phantomen notwendig ist. (orig.)

  15. Use of Verbal Descriptors, Thermal Scores and Electrical Pulp Testing Scores as Predictors of Tooth Pain Before and After Application of Benzocaine Gels into Cavities of Teeth with Pulpitis

    Science.gov (United States)

    Gangarosa, Louis P.; Ciarlone, Alfred E.; Neaverth, Elmer J.; Johnston, Carey A.; Snowden, J. Douglas; Thompson, William O.

    1989-01-01

    A double-blind pilot study was conducted on 27 consenting human volunteers who had irreversible pulpitis associated with persistent toothache pain from open carious lesions. Formulations tested contained either 0, 10%, or 20% benzocaine and were identified only by a numbered code. Before the experiment started, a small amount of a known 5% benzocaine gel was placed for 1 minute on the tongue of each patient to assure a sensation of numbness within the oral cavity. Then the test tooth was washed with a gentle stream of warm water and dried with gauze. A randomly selected test medication was placed into the open cavity and around the gingival margins for 5 minutes. Pre- and posttreatment tests were conducted at the following timed intervals: 0, 5, 15, 30, 45, 60, 75 and 90 minutes. The tests included degree of pain (rated: 0 = none, 1 = mild, 2 = moderate, 3 = severe); electrical pulp testing (EPT) by a modified, voltage-ramping instrument; and ice water testing (0.5 mL directed quickly onto sound enamel of the tooth and rated: 0 to 4, with 4 being intolerable). After testing, or when pain returned to baseline, endodontic procedures were performed. There was a significant increase (p pulpitis and control teeth, 3) there were no correlations between direction of EPT scores and pain relief, 4) cold water testing was a good predictor of whether or not a tooth had pulpitis, and 5) changes in cold water testing scores after treatment could not be correlated to relief of pain according to verbal descriptors. The effectiveness of benzocaine in relieving toothache pain verifies previous studies; however, a difference between 10% and 20% benzocaine could not be demonstrated probably because of two factors: 1) the present experiment had a small sample size, and 2) there was no direct measurement of duration of local anesthesia. PMID:2490060

  16. based gel polymer electrolytes

    Indian Academy of Sciences (India)

    Bull. Mater. Sci., Vol. 29, No. 7, December 2006, pp. 673–678. © Indian Academy of Sciences. 673. Investigation on poly (vinylidene fluoride) based gel polymer electrolytes ... (Alamgir and Abraham 1993; Sukeshini et al 1996; Ra- jendran and Uma ... Yang et al 1996; Ramesh and Arof 2001) and such elec- trolytes exhibit ...

  17. gel template method

    Indian Academy of Sciences (India)

    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 ...

  18. PCR amplification on microarrays of gel immobilized oligonucleotides

    Science.gov (United States)

    Strizhkov, Boris; Tillib, Sergei; Mikhailovich, Vladimir; Mirzabekov, Andrei

    2003-11-04

    The invention relates two general methods for performing PCR amplification, combined with the detection and analysis of the PCR products on a microchip. In the first method, the amplification occurs both outside and within a plurality of gel pads on a microchip, with at least one oligonucleotide primer immobilized in a gel pad. In the second method, PCR amplification also takes place within gel pads on a microchip, but the pads are surrounded by a hydrophobic liquid such as that which separates the individual gel pads into environments which resemble micro-miniaturized test tubes.

  19. Detection of Aspartic Proteinase Activities Using Gel Zymography.

    Science.gov (United States)

    Perera, Handunge Kumudu Irani

    2017-01-01

    Gel zymography is a two-stage process where the proteins from the test sample are first separated by electrophoresis followed by the detection of the activity of hydrolytic enzymes. Many zymography procedures use sodium dodecyl sulfate (SDS) polyacrylamide gels copolymerized with an appropriate substrate. The procedure described here uses native polyacrylamide gel electrophoresis (PAGE) in the absence of both SDS and substrate. In order to visualize aspartic proteinase activity, the gel is impregnated in bovine hemoglobin at pH 3.0 for 15 min after the electrophoresis procedure. Subsequently, the gel is incubated in a humid container in the absence of hemoglobin for 1 h at 37 °C. At the end, the gel is stained with amido black and destained. Clear areas against a dark background corresponding to aspartic proteinase activities can be detected.

  20. Comparative evaluation of the in vitro micronucleus test and the alkaline single cell gel electrophoresis assay for the detection of DNA damaging agents: genotoxic effects of cobalt powder, tungsten carbide and cobalt-tungsten carbide.

    Science.gov (United States)

    Van Goethem, F; Lison, D; Kirsch-Volders, M

    1997-08-01

    Although it is well known that micronuclei may arise from either DNA breakage leading to acentric chromosome fragments or from chromosome/chromatid lagging in anaphase, the ratio between the amount of DNA breakage induced and the frequency of micronuclei expressed in the following interphase is unclear. With the development of the alkaline single cell gel electrophoresis assay, which measures single strand and/or double strand breaks in a cell by cell approach, it is new possible to address this question at the cellular level. We therefore compared the genotoxic potential of pure cobalt powder (Co) and a cobalt-containing alloy, cobalt-tungsten carbide (WC-Co), involved in specific lung disorders, in parallel with the alkaline single cell gel electrophoresis (SCGE) assay (comet assay) and the cytokinesis-blocked micronucleus (MN) test, both carried out in vitro on isolated human leukocytes. The comet assay indicated that the WC-Co mixture produced a higher level of DNA damage than Co alone; WC alone was not able to induce a dose-dependent DNA breakage effect as was seen for Co and WC-Co. Results from the MN test confirmed these observations. It was clear that the clastogenic property of Co-containing dust is significantly enhanced when the Co metal is mixed with WC and suggested that their physicochemical characteristics may act as one of the important parameters responsible for the increased incidence of lung cancers observed in the population of hard metal workers. In agreement with data obtained in the same laboratory on liposoluble chemicals (PCBs and chlorinated aliphatic hydrocarbons) and from the literature, the results indicate that both the comet assay and the micronucleus test were able to detect differences in the genotoxic potential of the compounds studied. Although the micronucleus test seemed to be less sensitive to assess a synergistic DNA damaging potential of the mixture involved, it detects chromosomal aberrations (chromosome/genome mutations

  1. Comparative antimicrobial activities of aloe vera gel and leaf ...

    African Journals Online (AJOL)

    The comparative antimicrobial activities of the gel and leaf of Aloe vera were tested against Staphylococcus aureus, Pseudomonas aeruginosa, Trichophyton mentagraphytes, T. schoeleinii, Microsporium canis and Candida albicans. Ethanol was used for the extraction of the leaf after obtaining the gel from it. Antimicrobial ...

  2. Growth, characterization and dielectric property studies of gel grown ...

    Indian Academy of Sciences (India)

    Administrator

    Dielectric constant and dielectric loss have been calculated and discussed as a function of frequency at different temperatures. ... The stock solu- tion is added until the pH of the gel is set at the desired value. Test tubes were then tightly closed to prevent evaporation and contamination of the exposed surface of the gel by ...

  3. 3D Architectured Polyazomethine Gel Synthesis: Its Self Assembled ...

    Indian Academy of Sciences (India)

    23

    synthesis of polyazomethine polymer gel materials. The synthesized polymer gel is characterized by different physical techniques for testing its proper existence such as FESEM analysis, TGA analysis, DSC analysis, FTIR analysis and EDXS analysis. The morphological study has revealed that the material is having 3D ...

  4. Development and evaluation of ibuprofen transdermal gel formulations

    African Journals Online (AJOL)

    A commercial ibuprofen gel product (Ibutop®) was used as a reference. Results: The formulations containing 5 % of either menthol or glycerol as permeation enhancers gave drug release patterns comparable to that of the reference product. Propanol increased the apparent viscosity of the test gels to the same extent as that ...

  5. Biopolymer gels containing fructooligosaccharides.

    Science.gov (United States)

    Silva, Karen Cristina Guedes; Sato, Ana Carla Kawazoe

    2017-11-01

    The influence of the addition of fructooligosaccharide (FOS) in an external gelated alginate/gelatin biopolymer matrix, was evaluated in order to produce biopolymeric structures with functional effects. Solutions were characterized regarding their rheological properties, macrogels regarding their microstructure and mechanical properties and microgels were characterized in relation to their particle size distribution and morphology. Close relationship was found between the microstructure, rheological and mechanical properties of the biopolymeric systems. An increased viscosity and accentuated elastic and pseudoplastic behavior were associated to denser microstructures. The FOS addition caused changes in the evaluated properties, resulting in more cohesive structures, with smaller pores and higher viscosity, compared to alginate-gelatin gels. The addition of 3% FOS to biopolymeric system provided an optimal condition, allowing the formation of stronger gels, with smaller pores and beads with smaller sizes, indicating the potential use of these functional systems as texture modifiers or encapsulation systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. DNA DAMAGE QUANTITATION BY ALKALINE GEL ELECTROPHORESIS.

    Energy Technology Data Exchange (ETDEWEB)

    SUTHERLAND,B.M.; BENNETT,P.V.; SUTHERLAND, J.C.

    2004-03-24

    Physical and chemical agents in the environment, those used in clinical applications, or encountered during recreational exposures to sunlight, induce damages in DNA. Understanding the biological impact of these agents requires quantitation of the levels of such damages in laboratory test systems as well as in field or clinical samples. Alkaline gel electrophoresis provides a sensitive (down to {approx} a few lesions/5Mb), rapid method of direct quantitation of a wide variety of DNA damages in nanogram quantities of non-radioactive DNAs from laboratory, field, or clinical specimens, including higher plants and animals. This method stems from velocity sedimentation studies of DNA populations, and from the simple methods of agarose gel electrophoresis. Our laboratories have developed quantitative agarose gel methods, analytical descriptions of DNA migration during electrophoresis on agarose gels (1-6), and electronic imaging for accurate determinations of DNA mass (7-9). Although all these components improve sensitivity and throughput of large numbers of samples (7,8,10), a simple version using only standard molecular biology equipment allows routine analysis of DNA damages at moderate frequencies. We present here a description of the methods, as well as a brief description of the underlying principles, required for a simplified approach to quantitation of DNA damages by alkaline gel electrophoresis.

  7. Chiromagnetic nanoparticles and gels

    Science.gov (United States)

    Yeom, Jihyeon; Santos, Uallisson S.; Chekini, Mahshid; Cha, Minjeong; de Moura, André F.; Kotov, Nicholas A.

    2018-01-01

    Chiral inorganic nanostructures have high circular dichroism, but real-time control of their optical activity has so far been achieved only by irreversible chemical changes. Field modulation is a far more desirable path to chiroptical devices. We hypothesized that magnetic field modulation can be attained for chiral nanostructures with large contributions of the magnetic transition dipole moments to polarization rotation. We found that dispersions and gels of paramagnetic Co3O4 nanoparticles with chiral distortions of the crystal lattices exhibited chiroptical activity in the visible range that was 10 times as strong as that of nonparamagnetic nanoparticles of comparable size. Transparency of the nanoparticle gels to circularly polarized light beams in the ultraviolet range was reversibly modulated by magnetic fields. These phenomena were also observed for other nanoscale metal oxides with lattice distortions from imprinted amino acids and other chiral ligands. The large family of chiral ceramic nanostructures and gels can be pivotal for new technologies and knowledge at the nexus of chirality and magnetism.

  8. Polyacrylamide gel electrophoresis of RNA.

    Science.gov (United States)

    Rio, Donald C; Ares, Manuel; Hannon, Gregory J; Nilsen, Timothy W

    2010-06-01

    Perhaps the most important and certainly the most often used technique in RNA analysis is gel electrophoresis. This technique is generally applicable for RNA detection, quantification, purification by size, and quality assessment. Because RNAs are negatively charged, they migrate toward the anode in the presence of electric current. The gel acts as a sieve to selectively impede the migration of the RNA in proportion to its mass, given that its mass is generally proportional to its charge. Because mass is approximately related to chain length, the length of an RNA is more generally determined by its migration. In addition, topology (i.e., circularity) can affect migration, making RNAs appear longer on the gel than they actually are. Gels are used in a wide variety of techniques, including Northern blotting, primer extension, footprinting, and analyzing processing reactions. They are invaluable as preparative and fractionating tools. There are two common types of gel: polyacrylamide and agarose. For most applications, denaturing acrylamide gels are most appropriate. These gels are extremely versatile and can resolve RNAs from ~600 to RNA-protein complexes, native gels are appropriate. The only disadvantage to acrylamide gels is that they are not suitable for analyzing large RNAs (> or =600 nt); for such applications, agarose gels are preferred. This protocol describes how to prepare, load, and run polyacrylamide gels for RNA analysis.

  9. Aging and nonlinear rheology of thermoreversible colloidal gels

    Science.gov (United States)

    Wagner, Norman; Gordon, Melissa; Kloxin, Christopher

    Colloidal dispersions are found in a wide variety of consumer products such as paint, food and pharmaceuticals. We investigate gel formation and aging in a thermoreverible gel consisting of octadecyl-coated silica nanoparticles suspended in n-tetradecane. In this system, the octadecyl brush can undergo a phase change allowing the attractions between particles to be tuned by temperature (1,2). By probing the system with steady shear and large amplitude oscillatory shear, we have studied the effect of thermal history and shear history on gel formation and gel mechanical properties during aging. Gels were formed by approaching a common temperature from above and below to determine a reference state from which creep tests were conducted. Creep ringing was observed as expected for the viscoelastic gel. The rheological aging is interpreted in terms of the gel microstructure formed with differing thermal and shear histories to determine how processing affects structure. Recently proposed scaling laws for the rheology and structure under flow are explored within the context of gel aging (3). Through rheological and microstructural measurements, we will further the understanding of gel formation and aging in this model system which may be applied to processing conditions in an industrial setting.

  10. Establishment of gel materials with different mechanical properties by 3D gel printer SWIM-ER

    Science.gov (United States)

    Ota, Takafumi; Tase, Taishi; Okada, Koji; Saito, Azusa; Takamatsu, Kyuuichiro; Kawakami, Masaru; Furukawa, Hidemitsu

    2016-04-01

    A 3D printer is a device which can directly produce objects whose shape is the same as the original 3D digital data. Hydrogels have unique properties such as high water content, low frictional properties, biocompatibility, material permeability and high transparency, which are rare in hard and dry materials. These superior characteristics of gels promise useful medical applications. We have been working on the development of a 3D gel printer, SWIM-ER (Soft and Wet Industrial - Easy Realizer), which can make models of organs and artificial blood vessels with gel material. However, 3D printing has a problem: the mechanical properties of the printed object vary depending on printing conditions, and this matter was investigated with SWIM-ER. In the past, we found that mechanical properties of 3D gel objects depend on the deposition orientation in SWIM-ER. In this study, gels were printed with different laser scanning speeds. The mechanical properties of these gels were investigated by compression tests, water content measurements and SMILS (Scanning Microscopic Light Scattering).

  11. Radiotherapy gel dosimetry

    International Nuclear Information System (INIS)

    Baldock, C.

    2002-01-01

    shapes and sizes while sparing normal tissue. The situation is further complicated if the normal tissues are critical organs or are particularly sensitive to radiation. Radiotherapy techniques employed to obtain a closer conformation of the dose distribution to the tumour volume are referred to as conformal radiotherapy techniques. The clinical implementation of conformal therapy has been delayed by limitations in the verification of conformal dose distributions calculated by treatment planning systems prior to the irradiation of the patient and the verification of complex treatments during its delivery to the patient. There are several aspects of conformal therapy that complicate dose verification. To achieve the dose distributions conforming to complex 3D volumes, high dose gradients arise in the treatment volume. Further, overdose or underdose regions can exist when separate radiation fields are used to deliver additional radiation. These aspects require that practical dose measurement (dosimetry) techniques be able to integrate dose over time and easily measure dose distributions in 3D with high spatial resolution. Traditional dosimeters, such as ion chambers, thermoluminescent dosimeters and radiographic film do not fulfil these requirements. Novel gel dosimetry techniques are being developed in which dose distributions can potentially be determined in vitro in 3D using anthropomorphic phantoms to simulate a clinically irradiated situation. As long ago as the 1950's, radiation-induced colour change in dyes was used to investigate radiation doses in gels. It was subsequently shown that radiation induced changes in nuclear magnetic resonance (NMR) relaxation properties of gels infused with conventional Fricke dosimetry solutions could be measured using magnetic resonance imaging (MRI). In Fricke gels, Fe 2+ ions in ferrous sulphate solutions are usually dispersed throughout a gelatin, agarose or PVA matrix. Radiation-induced changes in the dosimeters are considered to

  12. Clinical study on collagen gel droplet-embedded culture drug sensitivity test for multidrug combination chemotherapy and super selective intra-arterial infusion chemoradiotherapy in oral squamous cell carcinoma.

    Science.gov (United States)

    Sakuma, Kaname; Tamura, Ryuki; Hanyu, Shintaro; Takahashi, Haruka; Sato, Hideaki; Oneyama, Takahiro; Yamaguchi, Akira; Tanaka, Akira

    2017-12-01

    Using trace three-dimensional culture, the collagen gel droplet-embedded culture drug sensitivity test (CD-DST) can be tested even in cases with a small number of cells, including oral squamous cell carcinoma (OSCC), and evaluation of the antitumor effect with a drug concentration close to the in vivo level is possible. The present report aimed to evaluate the utility of the CD-DST in the assessment of the in vitro efficacy of single-agent and multidrug combination chemotherapy for OSCC in comparison with the clinical response rates and to examine the possible clinical application of CD-DST for such cases. A total of 33 OSCC patients from whom 33 samples were obtained from January 2010 to September 2015 were included. CD-DST was performed, individually and in combination, on the three drugs [i.e., cisplatin (CDDP), 5-fluorouracil (5-FU), and docetaxel (DOC)] and on super selective intra-arterial infusion chemoradiotherapy (IACRT). The overall evaluable rate of the CD-DST in OSCC was 81.8% (27 of 33 cases) and the sensitivity to each anticancer drug was evaluated. The in vitro efficacy rates of IACRT, cisplatin + 5-fluorouracil, and docetaxel + cisplatin + 5-fluorouracil (TPF) confirmed the estimated clinical response rates. In 14 of 33 patients, the results of CD-DST were compared with clinical efficacy, which was judged based on measurable lesions on imaging. For TPF therapy, the sensitivity test of the IACRT had a positive predictive value of 90.9% (10 of 11 cases) and a negative predictive value of 100% (3 of 3 cases); the accuracy of the susceptibility test for the anticancer agents was 92.8% (13 of 14 cases). The CD-DST may be useful in selecting multidrug combination chemotherapy and IACRT for OSCC, however, accumulation of further clinical data is required in the future.

  13. Antibacterial Activity of Copaiba Oil Gel on Dental Biofilm.

    Science.gov (United States)

    Simões, Cláudia A C G; Conde, Nikeila C de Oliveira; Venâncio, Gisely N; Milério, Patrícia S L L; Bandeira, Maria F C L; da Veiga Júnior, Valdir F

    2016-01-01

    Amazonian biodiversity products that have been used for years in folk medicine, have emerged as feasible and promising alternatives for the inhibition of microorganisms in dental biofilm. Copaiba oil, a phytotherapic agent widely used by the Amazonian populations, is known for its antibacterial, anti-inflammatory, anesthetic, healing and antitumor medicinal properties. The aim of this study was to evaluate the in vitro antibacterial activity of copaiba oil (Copaifera multijuga) gel against strains of Streptococcus sp present in dental biofilm. The copaiba oil was obtained and the chemical components were identified. The oil emulsions were formulated and used with the Brain Heart Infusion agar diffusion method with strains of Streptococcus mitis, Streptococcus constellatus and Streptococcus salivarius isolated from patients as well as standard strains of S. mitis (ATCC903), S. mutans (ATCC10449), S. sanguinis (ATCC15300) and S. oralis (ATCC10557). The study groups were as follows: experimental copaiba oil gel, 1% chlorhexidine gel (positive control) and base gel (negative control). The seeded plates were incubated at 37ºC for 12, 24 and 48 hours, respectively. The results obtained were analyzed by Shapiro-Wilk and Friedman Tests (p<0.05) for non parametric data and the Tukey test was used for pH values with 5% level of significance. The experimental copaiba oil gel and 1% chlorhexidine gel showed antibacterial activity against the tested microorganisms. The copaiba oil gel demonstrated antibacterial activity against all the strains of Streptococcus sp tested, suggesting that it can be used for dental biofilm control.

  14. The effects of brushing on human enamel surface roughness after NaF gel and theobromine gel exposure

    Science.gov (United States)

    Mahardhika, A.; Noerdin, A.; Eriwati, Y. K.

    2017-08-01

    This study aimed to determine the effects of brushing on human enamel surface roughness after different exposure times of 200 mg/L theobromine gel (8, 16, and 32 minutes) and 2% NaF gel (16 minutes). Twenty-four human upper premolars were used and divided into four groups. Group 1 was exposed to 2% NaF gel for 16 minutes. In contrast, groups 2, 3, and 4 were exposed to 200 mg/L theobromine gel for 8 minutes, 16 minutes, and 32 minutes, and each group was then brushed for 9 minutes and 20 seconds. After the treatment, samples were tested using a surface roughness tester (Mitutoyo SJ 301, Japan). The Wilcoxon test showed significant changes (p theobromine gel or NaF gel and after brushing for 9 minutes and 20 seconds. It can be concluded that exposure to 200 mg/L theobromine gel or 2% NaF gel can soften the enamel surface and then increase roughness after brushing.

  15. Gel polymer electrolytes for batteries

    Science.gov (United States)

    Balsara, Nitash Pervez; Eitouni, Hany Basam; Gur, Ilan; Singh, Mohit; Hudson, William

    2014-11-18

    Nanostructured gel polymer electrolytes that have both high ionic conductivity and high mechanical strength are disclosed. The electrolytes have at least two domains--one domain contains an ionically-conductive gel polymer and the other domain contains a rigid polymer that provides structure for the electrolyte. The domains are formed by block copolymers. The first block provides a polymer matrix that may or may not be conductive on by itself, but that can soak up a liquid electrolyte, thereby making a gel. An exemplary nanostructured gel polymer electrolyte has an ionic conductivity of at least 1.times.10.sup.-4 S cm.sup.-1 at 25.degree. C.

  16. Thoria sol-gel processes

    International Nuclear Information System (INIS)

    Matthews, R.B.

    1978-10-01

    Alternate fuel fabrication techniques are being developed at WNRE as part of the thorium fuel cycle program. The sol-gel techniques are attractive and this report assembles and summarizes information relating to thoria sol-gel fuels. Some background information on the behaviour and advantages of sol-gel fuel forms is presented, followed by a review of relevant colloid chemistry and an explanation of the fundamental steps of sol-gel processes. Finally, several variants to the basic process are reviewed and evaluated. (author)

  17. Radiotherapy gel dosimetry: a review

    International Nuclear Information System (INIS)

    Baldock, C.

    2003-01-01

    Radiation therapy or radiotherapy is a common form of cancer treatment. Recent advances in radiotherapy such as intensity modulated radiation therapy indicate that treatment outcomes may be improved. The principle limitation of these more advanced techniques of radiation therapy is the ability to quantify the absorbed radiation dose to the tumour which is related to the 3- dimensional geometry of the tumour. The main advances in 3-dimensional radiation dosimetry are the development of radiation sensitive polymer gel dosimeters. The use of radiation sensitive gels for radiation dosimetry in cancer therapy was first suggested in the 1950s. It was subsequently shown in 1984 that radiation induced changes in nuclear magnetic resonance relaxation properties of gels infused with conventional Fricke dosimetry solutions could be measured. Due to diffusion-related limitations in the use of Fricke gels, alternative polymer gel dosimeters were subsequently suggested in 1992. Since then, both magnetic resonance and optical imaging techniques have been used to evaluate polymer gel dosimeters to produce three-dimensional radiation dose distributions. More recently the uses of x-ray computer tomography and vibrational spectroscopy have also been demonstrated as valuable techniques in the evaluation of these dosimetry gels. Although not yet used routinely clinically, applications of these radiologically soft-tissue equivalent gel dosimeters have been shown to have great potential in the evaluation of complex radiation dose distributions. A review of 3-dimensional radiotherapy gel dosimetry is presented

  18. Application of phase diagrams to obtain a new surfactant-based fracturing gel; Aplicacao de diagrama de fases para obtencao de um novo gel de fraturamento hidraulico

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, Tereza N. de Castro; Santana, Vanessa C.; Dantas Neto, Afonso A.; Franca Neta, Luzia S. de; Albuquerque, Heraldo S. [Rio Grande do Norte Univ., Natal, RN (Brazil)]. E-mail: tereza@eq.ufrn.br

    2003-07-01

    Through pseudo ternary phases diagram was defined a gel area with the objective of obtaining a new surfactant-based fracturing gel. The surfactant used was synthesized from regional vegetable oil. Fracturing gel properties, like: viscosity, leak off coefficient and proppant-settling rate were analyzed. The obtained results with the surfactant-based gel had its properties compared with a HPG-based gel (hydroxypropyl guar). Rheological tests was accomplished at 100 s{sup -1} being varied the temperature from 26 to 86 deg C, where the surfactant-based gel showed great results. The leak off coefficient was determined by static filtration and the new gel presented smaller coefficient in relation to the HPG gel. The proppant-setting rate was also determined in the gel and, the surfactant-based gel showed good static proppant support. One can conclude that obtained gel presents compatible characteristics when compared with the HPG gel, without the inconvenience of leaving insoluble residues in the well. (author)

  19. Comparison of Two Types of Gels in Improving Burn Wound

    Directory of Open Access Journals (Sweden)

    Rahimzadeh Golnar

    2014-01-01

    Full Text Available Objective: Kefir are natural probiotic compounds with anti-inflammatory properties, which were tested in experimental burn injury. Kefir gels were prepared from an extract of continuously cultured kefir in Man, Rogosa and Sharpe Broth medium for 48 and 96 h. Their extracts were used for evaluation of antibacterial effect against Pseudomonas aeruginosa in standard sample (ATCC 27853 and samples taken from patients with burns. The antibacterial effect of different kefir extract was assessment of minimum inhibitory concentration and minimum bactericidal concentration. The density of bacteria and percentage of organic acids (lactic and acetic acids were also determined. Materials and Methods: Similar burn injuries were made on dorsal skin surface of 40 rats. The rats were divided into 5 groups of 8 rats each. The base gel, silver sulfadiazine ointment, kefir 48 h gel, kefir 96 h gel were applied twice daily. Burn wound area was measured at baseline, 1 and 2 weeks. Results: Results indicated that by increasing the time of fermentation, concentration of lactic and acetic acid increased in orders of: Kefir 48 h < kefir 96 h, the end of the 2nd week the percentage of wound size were lowest in order of kefir 96 h gel < kefir grains 48 h gel < silver sulfadiazine 1% < untreated and based gel groups. Conclusion: In conclusion, the kefir gel therapy was an effective therapeutic approach to improve outcomes after severe burn when compared with conventional silver sulfadiazine treatment.

  20. Screening of mucoadhesive vaginal gel formulations

    Directory of Open Access Journals (Sweden)

    Ana Ochoa Andrade

    2014-12-01

    Full Text Available Rational design of vaginal drug delivery formulations requires special attention to vehicle properties that optimize vaginal coating and retention. The aim of the present work was to perform a screening of mucoadhesive vaginal gels formulated with carbomer or carrageenan in binary combination with a second polymer (carbomer, guar or xanthan gum. The gels were characterised using in vitroadhesion, spreadability and leakage potential studies, as well as rheological measurements (stress and frequency sweep tests and the effect of dilution with simulated vaginal fluid (SVF on spreadability. Results were analysed using analysis of variance and multiple factor analysis. The combination of polymers enhanced adhesion of both primary gelling agents, carbomer and carrageenan. From the rheological point of view all formulations presented a similar behaviour, prevalently elastic and characterised by loss tangent values well below 1. No correlation between rheological and adhesion behaviour was found. Carbomer and carrageenan gels containing the highest percentage of xanthan gum displayed good in vitro mucoadhesion and spreadability, minimal leakage potential and high resistance to dilution. The positive results obtained with carrageenan-xanthan gum-based gels can encourage the use of natural biocompatible adjuvants in the composition of vaginal products, a formulation field that is currently under the synthetic domain.

  1. Effectiveness of Gel Repellents on Feral Pigeons

    Directory of Open Access Journals (Sweden)

    Birte Stock

    2013-12-01

    Full Text Available Millions of feral pigeons (Columba livia live in close association with the human population in our cities. They pose serious health risks to humans and lead to high economic loss due to damage caused to buildings. Consequently, house owners and city authorities are not willing to allow pigeons on their buildings. While various avian repellents are regularly introduced onto the market, scientific proof of efficacy is lacking. This study aimed at testing the effectiveness of two avian gel repellents and additionally examined their application from animal welfare standpoint. The gels used an alleged tactile or visual aversion of the birds, reinforced by additional sensory cues. We mounted experimental shelves with the installed repellents in a pigeon loft and observed the behavior of free-living feral pigeons towards the systems. Both gels showed a restricted, transient repellent effect, but failed to prove the claimed complete effectiveness. Additionally, the gels’ adhesive effect remains doubtful in view of animal welfare because gluing of plumage presents a risk to feral pigeons and also to other non-target birds. This study infers that both gels lack the promised complete efficacy, conflict with animal welfare concerns and are therefore not suitable for feral pigeon management in urban areas.

  2. Rheology and structure of milk protein gels

    NARCIS (Netherlands)

    Vliet, van T.; Lakemond, C.M.M.; Visschers, R.W.

    2004-01-01

    Recent studies on gel formation and rheology of milk gels are reviewed. A distinction is made between gels formed by aggregated casein, gels of `pure` whey proteins and gels in which both casein and whey proteins contribute to their properties. For casein' whey protein mixtures, it has been shown

  3. Tough Amphiphilic Gels for Antifouling Applications

    Science.gov (United States)

    Villada, Laura M.

    concentration of crosslinking agent. The resultant variation in network mesh size had the strongest correlation with the BSA adsorption (R2 = 0.90) and algal spore attachment (R2 = 0.73). The second system evaluated was based upon a new siloxane non-isocyanate urethane divinyl monomer (NIUDMA) that was synthesized using environmentally friendly methods in order to produce more mechanically durable gels. A crosslinked amphiphilic network was synthesized utilizing NIUDMA in conjunction with the relatively hydrophobic hexafluorobutyl methacrylate (HFBMA) with hydrophilic HEMA. The initial HFBMA and HEMA feed composition was varied, and the effect on gel properties was equated to anti-biofouling efficacy. The different gel compositions altered the surface chemistry slightly and the structure of their surface; however, the greatest difference was seen in the bulk structure and mechanical properties. The elastic moduli measured for these gels was much higher than the gels previously tested; it ranged from 2 MPa to as high as 140 MPa by varying the ratio of hydrophilic (20 - 90 mol%) to hydrophobic (0 - 70 mol%) monomer concentration. For the NIUDMA gels, the biofouling assays performed to probe the effect of gel properties included U. linza sporeling attachment, N. incerta diatom and C. lytica bacteria biofilm growth and removal, and A. Amphitrite adult barnacle reattachment. The most effective results were seen with the fouling release results of diatoms, with up to 96% reduction, and marine bacteria with up to 98% reduction after an applied water pressure of 138 kPa. These two microfouling marine organisms are part of the first stages of the biofouling process, and reducing their attachment and adhesion is critical for preventing or reducing the later stages. There were complex trends seen with the properties of the gels and the bioassay results. Overall, the NIUDMA10 networks had comparable results to commercial coatings against spores, diatoms and marine bacteria.

  4. Gel placement in porous media

    NARCIS (Netherlands)

    F.J. Vermolen; J. Bruining; C.J. van Duijn (Hans)

    1999-01-01

    textabstractIn this paper we analyse advective transport of polymers, crosslinkers and gel, taking into account non-equilibrium gelation, gel adsorption and crosslinker precipitation. In absence of diffusion/dispersion the resulting model consists of hyperbolic transport-reaction equations. These

  5. Data on DNA gel sample load, gel electrophoresis, PCR and cost analysis

    Directory of Open Access Journals (Sweden)

    Ramona Kuhn

    2018-02-01

    Full Text Available The data presented in this article provide supporting information to the related research article “Comparison of ten different DNA extraction procedures with respect to their suitability for environmental samples” (Kuhn et al., 2017 [1]. In that article, we compared the suitability of ten selected DNA extraction methods based on DNA quality, purity, quantity and applicability to universal PCR. Here we provide the data on the specific DNA gel sample load, all unreported gel images of crude DNA and PCR results, and the complete cost analysis for all tested extraction procedures and in addition two commercial DNA extraction kits for soil and water. Keywords: Cost analysis, DNA sample load, Gel electrophoresis

  6. Antibacterial Inhibitory Effects of Punica Granatum Gel on Cariogenic Bacteria: An in vitro Study.

    Science.gov (United States)

    Millo, Grazielle; Juntavee, Apa; Ratanathongkam, Ariya; Nualkaew, Natsajee; Peerapattana, Jomjai; Chatchiwiwattana, Supaporn

    2017-01-01

    This study evaluated the in vitro antibacterial effects of the formulated Punica granatum (PG) gel against Streptococcus mutans, Streptococcus sanguinis, and Lactobacillus casei. The PG extract was dissolved in water at 500 mg/mL. High performance liquid chromatography (HPLC) was used for identification and quantification of chemical marker punicalagin. Minimum bactericidal concentration (MBC) and time-kill assay (TKA) were investigated. Antibacterial activities of the formulated PG gel, 2% chlorhexidine (CHX) gel and blank gel were tested by measuring the zones of inhibition through agar well diffusion method. The HPLC results showed presence of punicalagin at 2023.58 ± 25.29 pg/mL in the aqueous PG extract and at 0.234% (w/w) in the formulated PG gel. The MBC for S. mutans, S. Sanguinis, and L. casei were 250, 125, and 500 mg/mL respectively. The TKA of 500 mg/mL aqueous PG extract showed total inhibition of S. mutans, S. Sanguinis, and L. casei at 6, 1, and 24 hours contact time respectively. Agar well diffusion revealed that for S. mutans, CHX gel > PG gel > blank gel; for S. sanguinis, CHX gel = PG gel > blank gel; for L. casei, CHX gel > PG gel = blank gel. Comparison of the PG gel potency showed that S. sanguinis = S. mutans > L. casei. The PG gel equivalent to 0.234% punicalagin (w/w) inhibited S. mutans and S. sanguinis but not L. casei within 24 hours incubation period and has the potential to be used for caries prevention. Millo G, Juntavee A, Ratanathongkam A, Nualkaew N, Peerapattana J, Chatchiwiwattana S. Antibacterial Inhibitory Effects of Punica Granatum Gel on Cariogenic Bacteria: An in vitro Study. Int J Clin Pediatr Dent 2017;10(2):152-157.

  7. Normal modes of weak colloidal gels

    Science.gov (United States)

    Varga, Zsigmond; Swan, James W.

    2018-01-01

    The normal modes and relaxation rates of weak colloidal gels are investigated in calculations using different models of the hydrodynamic interactions between suspended particles. The relaxation spectrum is computed for freely draining, Rotne-Prager-Yamakawa, and accelerated Stokesian dynamics approximations of the hydrodynamic mobility in a normal mode analysis of a harmonic network representing several colloidal gels. We find that the density of states and spatial structure of the normal modes are fundamentally altered by long-ranged hydrodynamic coupling among the particles. Short-ranged coupling due to hydrodynamic lubrication affects only the relaxation rates of short-wavelength modes. Hydrodynamic models accounting for long-ranged coupling exhibit a microscopic relaxation rate for each normal mode, λ that scales as l-2, where l is the spatial correlation length of the normal mode. For the freely draining approximation, which neglects long-ranged coupling, the microscopic relaxation rate scales as l-γ, where γ varies between three and two with increasing particle volume fraction. A simple phenomenological model of the internal elastic response to normal mode fluctuations is developed, which shows that long-ranged hydrodynamic interactions play a central role in the viscoelasticity of the gel network. Dynamic simulations of hard spheres that gel in response to short-ranged depletion attractions are used to test the applicability of the density of states predictions. For particle concentrations up to 30% by volume, the power law decay of the relaxation modulus in simulations accounting for long-ranged hydrodynamic interactions agrees with predictions generated by the density of states of the corresponding harmonic networks as well as experimental measurements. For higher volume fractions, excluded volume interactions dominate the stress response, and the prediction from the harmonic network density of states fails. Analogous to the Zimm model in polymer

  8. Tensile Properties of Poly (N-vinyl caprolactam) Gels

    Science.gov (United States)

    Morgret, Leslie D.; Hinkley, Jeffrey A.

    2004-01-01

    N-vinyl caprolactam was copolymerized with ethylene glycol dimethacrylate using a free-radical initiator in alcohol/water solution. The resulting gels were thermally-responsive in water, undergoing an approximate fivefold reversible volume shrinkage between room temperature and ca. 50 C. Tensile testing showed that the stress-strain behavior was qualitatively different in the collapsed state above the temperature-induced transition. At the higher temperature, gels were stiffer, more ductile, and showed greater time dependence. Implications for the design of gel actuators are briefly discussed.

  9. Characterisation of drug resistance of nosocomial ESBL-producing E. coli isolates obtained from a Turkish university hospital between 2009 and 2012 by pulsed field gel electrophoresis and antibiotic resistance tests.

    Science.gov (United States)

    Karagöz, Alper; Sunnetcioglu, Mahmut; Ceylan, Mehmet Resat; Bayram, Yasemin; Yalcin, Gozde; Kocak, Nadir; Suvak, Burak; Andac, Cenk A

    2016-01-01

    In this study, drug resistance of 28 ESBL-producing Escherichia coli isolates obtained from 144 patients hospitalized at the Yüzüncüyil University Hospital at Van (YUH), Turkey, between 2009 and 2012 were characterized by pulsed field gel electrophoresis and antibiotic susceptibility tests. Antibiotic resistance profile was determined by Phoenix automated system (BD, USA). The ratio of ESBL-producing E. coli strains was determined to be 19.4% (28 out of 144 E. coli isolates). It was determined that the anaesthesiology, paediatrics and thoracic medicine intensive care units in YUH were cross-contaminated between 2009 and 2012 by ESBL-producing E. coli strains, which is a sign of nosocomial infection in YUH. Analysis of PFGE results gave rise to two main PFGE profiles, profile-A with four subprofiles and profile-B with three subprofiles, where profile-A predominates over profile-B (14%). Comparison of the antibiotic resistance profile with the PFGE profile yielded similarities while some differences also exist due to either identical restriction enzyme cutting sites with slightly different genetic sequences in between the cutting sites or newly formed restriction enzyme cutting sites that do not affect antibiotic resistance genes. Enterobacteriaceae, particularly E. coli, have developed resistance in YUH by producing ESBLs against oxyimino and non-oxyimino cephalosporins, and penicillin-type antibiotics. Therefore, more effective antibiotics such as cefoxitin or cefoperazone-sulbactam should be used for the treatment of future nosocomial infections in YUH while hospital staff should take care with hygiene, such as hand washing.

  10. Influence of colloidal silicon dioxide on gel strength, robustness, and adhesive properties of diclofenac gel formulation for topical application.

    Science.gov (United States)

    Lu, Zheng; Fassihi, Reza

    2015-06-01

    The objective of this study is to identify the extent of stiffness, adhesiveness, and thixotropic character of a three-dimensional gel network of a 1% diclofenac sodium topical gel formulation in the presence and absence of colloidal silicon dioxide (CSD) and assess its ease of application and adhesiveness using both objective and subjective analysis. The 1% diclofenac gel was mixed with different amounts of CSD (e.g., 0.5, 1, 2, 3, and 5% w/w) and allowed to equilibrate prior to testing. The texture analyzer in combination with a cone-cap assembly was used to objectively investigate the changes in spreadability and adhesiveness of the gel system before and after addition of CSD. Results indicate that an increase in pliability and adhesiveness at levels ≥2 to ≤5% w/w of CSD dispersed in the gel ensues. For subjective analysis, gels with (2% w/w) CSD and in the absence of CSD were uniformly applied to a 20-cm(2) (5 cm × 4 cm) surface area on the forearms of healthy volunteers and vehicle preferences by the volunteers regarding ease of application, durability on the skin, compliance, and feelings concerning its textural properties were assessed. It appears that changes in the gel formulation with the addition of CSD enhance gel viscosity and bonding to the skin. Results further show that changes in physical and rheological characteristics of gel containing 2% w/w CSD did not significantly change subject preferences for the gel preparations. These findings may help formulators to have additional options to develop more robust and cost-effective formulations.

  11. Chemical Gel for Surface Decontamination

    International Nuclear Information System (INIS)

    Jung, Chong Hun; Moon, J. K.; Won, H. J.; Lee, K. W.; Kim, C. K.

    2010-01-01

    Many chemical decontamination processes operate by immersing components in aggressive chemical solutions. In these applications chemical decontamination technique produce large amounts of radioactive liquid waste. Therefore it is necessary to develop processes using chemical gels instead of chemical solutions, to avoid the well-known disadvantages of chemical decontamination techniques while retaining their high efficiency. Chemical gels decontamination process consists of applying the gel by spraying it onto the surface of large area components (floors, walls, etc) to be decontaminated. The gel adheres to any vertical or complex surface due to their thixotropic properties and operates by dissolving the radioactive deposit, along with a thin layer of the gel support, so that the radioactivity trapped at the surface can be removed. Important aspects of the gels are that small quantities can be used and they show thixitropic properties : liquid during spraying, and solid when stationary, allowing for strong adherence to surfaces. This work investigates the decontamination behaviors of organic-based chemical gel for SS 304 metallic surfaces contaminated with radioactive materials

  12. Denaturing gradient gel electrophoresis

    International Nuclear Information System (INIS)

    Kocherginskaya, S.A.; Cann, I.K.O.; Mackie, R.I.

    2005-01-01

    It is worthwhile considering that only some 30 species make up the bulk of the bacterial population in human faeces at any one time based on the classical cultivation-based approach. The situation in the rumen is similar. Thus, it is practical to focus on specific groups of interest within the complex community. These may be the predominant or the most active species, specific physiological groups or readily identifiable (genetic) clusters of phylogenetically related organisms. Several 16S rDNA fingerprinting techniques can be invaluable for selecting and monitoring sequences or phylogenetic groups of interest and are described below. Over the past few decades, considerable attention was focussed on the identification of pure cultures of microbes on the basis of genetic polymorphisms of DNA encoding rRNA such as ribotyping, amplified fragment length polymorphism and randomly amplified polymorphic DNA. However, many of these methods require prior cultivation and are less suitable for use in analysis of complex mixed populations although important in describing cultivated microbial diversity in molecular terms. Much less attention was given to molecular characterization of complex communities. In particular, research into diversity and community structure over time has been revolutionized by the advent of molecular fingerprinting techniques for complex communities. Denaturing or temperature gradient gel electrophoresis (DGGE/TGGE) methods have been successfully applied to the analysis of human, pig, cattle, dog and rodent intestinal populations

  13. Fluoride Rinses, Gels and Foams

    DEFF Research Database (Denmark)

    Twetman, Svante; Keller, Mette K

    2016-01-01

    AIM: The aim of this conference paper was to systematically review the quality of evidence and summarize the findings of clinical trials published after 2002 using fluoride mouth rinses, fluoride gels or foams for the prevention of dental caries. METHODS: Relevant papers were selected after...... (6 on fluoride mouth rinse, 10 on fluoride gel and 3 on fluoride foam); 6 had a low risk of bias while 2 had a moderate risk. All fluoride measures appeared to be beneficial in preventing crown caries and reversing root caries, but the quality of evidence was graded as low for fluoride mouth rinse......, moderate for fluoride gel and very low for acidulated fluoride foam. No conclusions could be drawn on the cost-effectiveness. CONCLUSIONS: This review, covering the recent decade, has further substantiated the evidence for a caries-preventive effect of fluoride mouth rinse, fluoride gel and foam...

  14. Injectable gels for tissue engineering.

    Science.gov (United States)

    Gutowska, A; Jeong, B; Jasionowski, M

    2001-08-01

    Recently, tissue engineering approaches using injectable, in situ gel forming systems have been reported. In this review, the gelation processes and several injectable systems that exhibit in situ gel formation at physiological conditions are discussed. Applications of selected injectable systems (alginate, chitosan, hyaluronan, polyethylene oxide/polypropylene oxide) in tissue engineering are also described. Injectable polymer formulation can gel in vivo in response to temperature change (thermal gelation), pH change, ionic cross-linking, or solvent exchange. Kinetics of gelation is directly affected by its mechanism. Injectable formulations offer specific advantages over preformed scaffolds such as: possibility of a minimally invasive implantation, an ability to fill a desired shape, and easy incorporation of various therapeutic agents. Several factors need to be considered before an injectable gel can be selected as a candidate for tissue engineering applications. Apart from tissue-specific cell-matrix interactions, the following gel properties need to be considered: gelation kinetics, matrix resorption rate, possible toxicity of degradation products and their elimination routes, and finally possible interference of the gel matrix with histogenesis. Copyright 2001 Wiley-Liss, Inc.

  15. Strain identification in Rhizobium by starch gel electrophoresis of isoenzymes

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen; Nielsen, G.

    1985-01-01

    Sonieated extracts of rhizobia, especiaUy Rhizobium leguminosarum from pea and vetch, were run in horizontal starch gel electrophoresis in the cold. The rhizobia were grown on agar on a slime suppressing substrate of tryptone-yeast extract-CaCl2 with small amounts of mannitol, sorbitol and arabin......Sonieated extracts of rhizobia, especiaUy Rhizobium leguminosarum from pea and vetch, were run in horizontal starch gel electrophoresis in the cold. The rhizobia were grown on agar on a slime suppressing substrate of tryptone-yeast extract-CaCl2 with small amounts of mannitol, sorbitol...... and arabinose and other sugars as enzyme inducers. After electrophoresis the gels were separated into several slabs by a gel cutter. Each slab was stained for a particular enzyme. Among numerous enzyme systems tested we found useful variation in esterases (EC 3.1.1.1, EC 3.1.1.2), 3-hydroxybutyrate...

  16. The Influence of 5% KOH Immersion for Seaweed as Raw Materials for Air Freshener Gel

    Directory of Open Access Journals (Sweden)

    Riardi Pratista Dewa

    2014-12-01

    Full Text Available The effect of submersion KOH 5% for seaweed as raw materials products air freshener gel has been studied. Seaweed in Indonesia has a big potentially and it is commonly used in food products, beverages, pharmaceuticals and cosmetics. This research aims to use seaweed as a feedstock gel air freshener. Soaking seaweed with KOH was conducted to determine the nature of the water content and gel strength of the gel air freshener products generated given the scent of oranges and cloves. KOH concentration used was 5%. The results showed the water content of seaweed with KOH soaked lower than without KOH, whereas the gel strength with marinated seaweed KOH higher than without KOH. The results of organoleptic test, in this case the sense of smell, the air freshener gel product indicates that the product that uses citrus scent perfuming/lemon, panelists preferred more than the product is scented gel air freshener clove oil.

  17. Formulation of a poly herbal gel for uterus flux

    Directory of Open Access Journals (Sweden)

    M. Rezghi

    2017-11-01

    Full Text Available Background and objectives: Over the centuries, herbal drugs have been used as major sources of medicine for the prevention and treatment of diseases. In recent years, there has been an exponential growth in the field of herbal medicines and these drugs are gaining popularity both in developing and developed countries because of their natural origin and less side effects. The present research has been undertaken to formulate and evaluate an herbal gel for uterus flux based on Iranian traditional medicine references. Methods: An aqueous extracts of fruit peels of Punica granatum and leaves of Myrtus communis, ethanol extract of oleo gum resins of Boswellia carterii and hydro-alcoholic extract of Carum carvi fruits were obtained. The gel was prepared by using the plants extract, carbopol 940, propylene glycol, tri-ethanolamine and distilled water. Further, the prepared gel was evaluated for physicochemical and microbial characteristics. Moreover, accelerated laboratory stability tests were performed. Results: The results showed good appearance and homogeneity of the gel. It was yellow-brown in color with acceptable physicochemical characteristics. Besides, the gel was stable towards physical changes and successfully passed microbiological tests. Conclusion: The prepared gel contained tannins which are astringent agents; therefore, this product could be an appropriate candidate for disorders like uterus flux with respect to its traditional use.

  18. Bleach gel: a simple agarose gel for analyzing RNA quality.

    Science.gov (United States)

    Aranda, Patrick S; LaJoie, Dollie M; Jorcyk, Cheryl L

    2012-01-01

    RNA-based applications requiring high-quality, non-degraded RNA are a foundational element of many research studies. As such, it is paramount that the integrity of experimental RNA is validated prior to cDNA synthesis or other downstream applications. In the absence of expensive equipment such as microfluidic electrophoretic devices, and as an alternative to the costly and time-consuming standard formaldehyde gel, RNA quality can be quickly analyzed by adding small amounts of commercial bleach to TAE buffer-based agarose gels prior to electrophoresis. In the presence of low concentrations of bleach, the secondary structure of RNA is denatured and potential contaminating RNases are destroyed. Because of this, the 'bleach gel' is a functional approach that addresses the need for an inexpensive and safe way to evaluate RNA integrity and will improve the ability of researchers to rapidly analyze RNA quality. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Sol-gel-based biosensing applied to medicinal science.

    Science.gov (United States)

    Moreira, Felismina T C; Moreira-Tavares, Ana P; Sales, M Goreti F

    2015-01-01

    Biosensors have opened new horizons in biomedical analysis, by ensuring increased assay speed and flexibility, and allowing point-of-care applications, multi-target analyses, automation and reduced costs of testing. This has been a result of many studies merging nanotechnology with biochemistry over the years, thereby enabling the creation of more suitable environments to biological receptors and their substitution by synthetic analogue materials. Sol-gel chemistry, among other materials, is deeply involved in this process. Sol-gel processing allows the immobilization of organic molecules, biomacromolecules and cells maintaining their properties and activities, permitting their integration into different transduction devices, of electrochemical or optical nature, for single or multiple analyses. Sol-gel also allows to the production of synthetic materials mimicking the activity of natural receptors, while bringing advantages, mostly in terms of cost and stability. Moreover, the biocompatibility of sol-gel materials structures of biological nature allowed the use of these materials in emerging in vivo applications. In this chapter, biosensors for biomedical applications based on sol-gel derived composites are presented, compared and described, along with current emerging applications in vivo, concerning drug delivery or biomaterials. Sol-gel materials are shown as a promising tool for current, emerging and future medical applications.

  20. Lightweight, Soft Variable Stiffness Gel Spats for Walking Assistance

    Directory of Open Access Journals (Sweden)

    Yi Li

    2015-12-01

    Full Text Available With the rapid development of the aging society, many of the elderly people are in need of nursing care for their daily activities. Therefore, innovative technologies are needed to support the daily activities of elderly people and to lighten the heavy burden of nursing. We think the technology of soft actuators should be one of the key issues for developing such technologies. In this study, we focused on walking assistance for daily life and presented a preliminary work of developing novel poly vinyl chloride (PVC gel actuator-based lightweight and soft wearable assistive spats for supporting the walking motion of human. The PVC gel devices are incorporated in the generally used spats. The stiffness of the gel spats can be actively varied with the applied DC field turned on and off. The gel spats have the characteristics of a simple structure, a lightweight, easy to put on and take off, and with a high flexibility. A prototype was tested in the motions of lifting a foot and walking. It was found that the integrated electromyogram (IEMG and maximal voluntary contraction (%MVC values of the rectus femoris muscle reduced with the assistance of the gel spats, which demonstrated the potential of the gel spats as a device for walking assistance.

  1. Development of lidocaine gels for enhanced local anesthetic action.

    Science.gov (United States)

    Shin, Sang-Chul; Cho, Cheong-Weon; Yang, Kyu-Ho

    2004-12-09

    In relieving local pains, lidocaine, one of ester type local anesthetics, has been used. To develop the lidocaine gels of enhanced local anesthetic effects, hydroxypropyl methylcellulose (HPMC) based bioadhesive polymer gel containing an enhancer was formulated. As the drug concentration in the gels increased up to 3%, the permeation rate of drug linearly increased, thereafter reaching a plateau. As the temperature of surrounding solutions increased, the permeation of drug increased. The activation energy of drug permeation was 3.29 kcal/mol for lidocaine. The permeation rate of drug through skin was studied using various enhancers, such as glycols, non-ionic surfactants, and bile salts. Among the enhancers studied, diethylene glycol showed the greatest enhancing effects on drug permeation through skin. The analgesic activity was examined using a tail-flick analgesimeter. In the area under the efficacy curve (AUEC) of the rat-tail flick tests, lidocaine gel containing diethylene glycol showed about 3.89-fold increase in analgesic activity compared with the control. The addition of vasoconstrictor in the gels prolonged the analgesic effects. The result of this study supports that the bioadhesive gel with efficient anesthetic effect could be developed using HPMC with combination of enhancer and vasoconstrictor.

  2. Polyacrylamide temperature gradient gel electrophoresis.

    Science.gov (United States)

    Viglasky, Viktor

    2013-01-01

    Temperature Gradient Gel Electrophoresis (TGGE) is a form of electrophoresis in which temperature gradient is used to denature molecules as they move through either acrylamide or agarose gel. TGGE can be applied to analyze DNA, RNA, protein-DNA complexes, and, less commonly, proteins. Separation of double-stranded DNA molecules during TGGE relies on temperature-dependent melting of the DNA duplex into two single-stranded DNA molecules. Therefore, the mobility of DNA reflects not only the size of the molecule but also its nucleotide composition, thereby allowing separation of DNA molecules of similar size with different sequences. Depending on the relative orientation of electric field and temperature gradient, TGGE can be performed in either a parallel or a perpendicular mode. The former is used to analyze multiple samples in the same gel, whereas the later allows detailed analysis of a single sample. This chapter is focused on analysis of DNA by polyacrylamide TGGE using the perpendicular mode.

  3. Sol-gel derived sorbents

    Science.gov (United States)

    Sigman, Michael E.; Dindal, Amy B.

    2003-11-11

    Described is a method for producing copolymerized sol-gel derived sorbent particles for the production of copolymerized sol-gel derived sorbent material. The method for producing copolymerized sol-gel derived sorbent particles comprises adding a basic solution to an aqueous metal alkoxide mixture for a pH.ltoreq.8 to hydrolyze the metal alkoxides. Then, allowing the mixture to react at room temperature for a precalculated period of time for the mixture to undergo an increased in viscosity to obtain a desired pore size and surface area. The copolymerized mixture is then added to an immiscible, nonpolar solvent that has been heated to a sufficient temperature wherein the copolymerized mixture forms a solid upon the addition. The solid is recovered from the mixture, and is ready for use in an active sampling trap or activated for use in a passive sampling trap.

  4. Rheology of Emulsion-Filled Gels Applied to the Development of Food Materials

    Directory of Open Access Journals (Sweden)

    Ivana M. Geremias-Andrade

    2016-08-01

    Full Text Available Emulsion-filled gels are classified as soft solid materials and are complex colloids formed by matrices of polymeric gels into which emulsion droplets are incorporated. Several structural aspects of these gels have been studied in the past few years, including their applications in food, which is the focus of this review. Knowledge of the rheological behavior of emulsion-filled gels is extremely important because it can measure interferences promoted by droplets or particle inclusion on the textural properties of the gelled systems. Dynamic oscillatory tests, more specifically, small amplitude oscillatory shear, creep-recovery tests, and large deformation experiments, are discussed in this review as techniques present in the literature to characterize rheological behavior of emulsion-filled gels. Moreover, the correlation of mechanical properties with sensory aspects of emulsion-filled gels appearing in recent studies is discussed, demonstrating the applicability of these parameters in understanding mastication processes.

  5. Screening effect on nanostructure of charged gel

    DEFF Research Database (Denmark)

    Sugiyama, M; Annaka, M; Hino, M

    2004-01-01

    Charge screening effects on nanostructures of N-isopropylacrylamide-sodium acrylate (NIPA-SA) and -acrylic acid (NIPA-AAc) gels are investigated with small-angle neutron scattering. The NIPA-SA and NIPA-AAc gels with low water content exhibit microphase separations with different dimensions....... The dehydrated NIPA-SA gel also makes the microphase separation but the dehydrated NIPA-AAc gel does not. These results indicate that ionic circumstance around charged bases strongly affects the nanostructures both of the dehydrated gel and the gel with low water content. (C) 2004 Elsevier B. V. All rights...

  6. Screening effect on nanostructure of charged gel

    International Nuclear Information System (INIS)

    Sugiyama, Masaaki; Annaka, Masahiko; Hino, Masahiro; Fukunaga, Toshiharu; Vigild, Martin E.; Hara, Kazuhiro

    2004-01-01

    Charge screening effects on nanostructures of N-isopropylacrylamide-sodium acrylate (NIPA-SA) and -acrylic acid (NIPA-AAc) gels are investigated with small-angle neutron scattering. The NIPA-SA and NIPA-AAc gels with low water content exhibit microphase separations with different dimensions. The dehydrated NIPA-SA gel also makes the microphase separation but the dehydrated NIPA-AAc gel does not. These results indicate that ionic circumstance around charged bases strongly affects the nanostructures both of the dehydrated gel and the gel with low water content

  7. Screening effect on nanostructure of charged gel

    Science.gov (United States)

    Sugiyama, Masaaki; Annaka, Masahiko; Hino, Masahiro; Fukunaga, Toshiharu; E. Vigild, Martin; Hara, Kazuhiro

    2004-07-01

    Charge screening effects on nanostructures of N-isopropylacrylamide-sodium acrylate (NIPA-SA) and -acrylic acid (NIPA-AAc) gels are investigated with small-angle neutron scattering. The NIPA-SA and NIPA-AAc gels with low water content exhibit microphase separations with different dimensions. The dehydrated NIPA-SA gel also makes the microphase separation but the dehydrated NIPA-AAc gel does not. These results indicate that ionic circumstance around charged bases strongly affects the nanostructures both of the dehydrated gel and the gel with low water content.

  8. Nonlinear elasticity of alginate gels

    Science.gov (United States)

    Hashemnejad, Seyed Meysam; Kundu, Santanu

    Alginate is a naturally occurring anionic polysaccharide extracted from brown algae. Because of biocompatibility, low toxicity, and simple gelation process, alginate gels are used in biomedical and food applications. Here, we report the rheological behavior of ionically crosslinked alginate gels, which are obtained by in situ gelation of alginates with calcium salts, in between two parallel plates of a rheometer. Strain stiffening behavior was captured using large amplitude oscillatory shear (LAOS) experiments. In addition, negative normal stress was observed for these gels, which has not been reported earlier for any polysaccharide networks. The magnitude of negative normal stress increases with applied strain and can exceed that of the shear stress at large strain. Rheological results fitted with a constitutive model that considers both stretching and bending of chains indicate that nonlinearity is likely related to the stretching of the chains between the crosslink junctions. The results provide an improved understanding of the deformation mechanism of ionically crosslinked alginate gel and the results will be important in developing synthetic extracellular matrix (ECM) from these materials.

  9. Silica reinforced triblock copolymer gels

    DEFF Research Database (Denmark)

    Theunissen, E.; Overbergh, N.; Reynaers, H.

    2004-01-01

    The effect of silica and polymer coated silica particles as reinforcing agents on the structural and mechanical properties of polystyrene-poly(ethylene/butylene)-polystyrene (PS-PEB-PS) triblock gel has been investigated. Different types of chemically modified silica have been compared in order...

  10. Silicone Gel-Filled Breast Implants

    Science.gov (United States)

    ... and Prosthetics Breast Implants Silicone Gel-Filled Breast Implants Share Tweet Linkedin Pin it More sharing options ... it Email Print Description: Silicone gel-filled breast implants have a silicone outer shell that is filled ...

  11. Surface grafted chitosan gels. Part II. Gel formation and characterization

    DEFF Research Database (Denmark)

    Liu, Chao; Thormann, Esben; Claesson, Per M.

    2014-01-01

    Responsive biomaterial hydrogels attract significant attention due to their biocompatibility and degradability. In order to make chitosan based gels, we first graft one layer of chitosan to silica, and then build a chitosan/poly(acrylic acid) multilayer using the layer-by-layer approach. After...... detachment and decomposition. The chemical reaction between gluteraldehyde, the cross-linking agent, and chitosan was followed in situ using total internal reflection Raman (TIRR) spectroscopy, which provided a molecular insight into the complex reaction mechanism, as well as the means to quantify the cross......-linking density. The amount of poly(acrylic acid) trapped inside the surface grafted films was found to decrease with decreasing cross-linking density, as confirmed in situ using TIRR, and ex situ by Fourier transform infrared (FTIR) measurements on dried films. The responsiveness of the chitosan-based gels...

  12. Starch and chitosan oligosaccharides as interpenetrating phases in poly(N-isopropylacrylamide) injectable gels

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Jacquelin N.; Posada, James J. [Chemistry Department, B" 5IDA Research Group, Universidad Simón Bolívar, Caracas (Venezuela, Bolivarian Republic of); Rezende, Rodrigo A. [Divisão de Tecnologias Tridimensionais–Centro de Tecnologia da Informação Renato Archer, Campinas, SP (Brazil); Sabino, Marcos A., E-mail: msabino@usb.ve [Chemistry Department, B" 5IDA Research Group, Universidad Simón Bolívar, Caracas (Venezuela, Bolivarian Republic of); Divisão de Tecnologias Tridimensionais–Centro de Tecnologia da Informação Renato Archer, Campinas, SP (Brazil)

    2014-04-01

    Thermosensitive interpenetrating gels were prepared by physically blending poly(N-isopropylacrylamide) (PNIPA) as the matrix and the following polysaccharides as interpenetrating phases: chitosan oligosaccharides (identified as QNAD and QNED) and soluble starch (STARCH). The molecular weight of the dispersed phase, the free water/bound water ratio and the thermosensitivity (transition temperature: LCST) of the gels were determined. It was found that these gels are pseudoplastic and that their viscosity depends on the molecular weight of the dispersed phase. LCST transition occurred around 35–37 °C. The morphology of the porosity of the freeze-dried samples was studied by Scanning Electron Microscopy (SEM). An in vitro test of cell hemolysis on blood agar showed that these gels are noncytotoxic. According to the results obtained, these interpenetrating gels show characteristics of an injectable material, and have a transition LCST at body temperature, which reinforces their potential to be used in the surgical field and as scaffolds for tissue engineering. - Highlights: • Physical blends were prepared to obtain thermosensitive gels PNIPA/polysaccharides. • Rheological test allowed verifying the injectability of the gels. • Gels showed a LCST ∼ 37 °C, which makes them interesting for biomedical applications. • Porosity is a function of hydrophobicity/hydrophilicity/molecular weight of phases. • The PNIPA/starch gel showed better morphology as scaffold for tissue engineering.

  13. Slow Release of Plant Volatiles Using Sol-Gel Dispensers.

    Science.gov (United States)

    Bian, L; Sun, X L; Cai, X M; Chen, Z M

    2014-12-01

    The black citrus aphid, also known as the tea aphid, (Toxoptera aurantii Boyer) attacks economically important crops, including tea (Camellia sinensis (L.) O. Kuntze). In the current study, silica sol-gel formulations were screened to find one that could carry and release C. sinensis plant volatiles to lure black citrus aphids in a greenhouse. The common plant volatile trans-2-hexen-1-al was used as a model molecule to screen for suitable sol-gel formulations. A zNose (Electronic Sensor Technology, Newbury Park, CA) transportable gas chromatograph was used to continuously monitor the volatile emissions. A sol-gel formulation containing tetramethyl orthosilicate and methyltrimethoxysilane in an 8:2 (vol:vol) ratio was selected to develop a slow-release dispenser. The half-life of trans-2-hexen-1-al in the sol-gel dispenser increased slightly with the volume of this compound in the dispenser. Ten different volatiles were tested in the sol-gel dispenser. Alcohols of 6-10 carbons had the longest half-lives (3.01-3.77 d), while esters of 6-12 carbons had the shortest (1.53-2.28 d). Release of these volatiles from the dispensers could not be detected by the zNose after 16 d (cis-3-hexenyl acetate) to 26 d (3,7-dimethylocta-1,6-dien-3-ol). In greenhouse experiments, trans-2-hexen-1-al and cis-3-hexen-1-ol released from the sol-gel dispensers attracted aphids for ≍17 d, and release of these volatiles could not be detected by the zNose after ≍24 d. The sol-gel dispensers performed adequately for the slow release of plant volatiles to trap aphids in the greenhouse. © 2014 Entomological Society of America.

  14. Growth and study of barium oxalate single crystals in agar gel

    Indian Academy of Sciences (India)

    Unknown

    In the present work, agar–agar gel (Brezina and Harvan- kova 1991; Agrawal et al 1999) was preferentially used for the growth of crystals by single and double diffusion tech- niques. A test tube having 25 cm in length and 2⋅5 cm in dia- meter was employed. In single diffusion, hot aqueous agar gel and oxalic acid solution ...

  15. Fluorine profiling after application of various anti-caries gels

    Science.gov (United States)

    Zschau, H.-E.; Plier, F.; Otto, G.; Wyrwich, C.; Treide, A.

    1990-04-01

    Two newly developed caries-preventing gels were tested together with Elmex R on pre-school children over a time of 3 years. Proton-induced gamma-ray emission spectrometry (PIGE) was used to measure the fluorine profiles in milk teeth (incisors). In accordance with the clinical statement the results allow to produce a new anti-caries drug.

  16. Synthesis of hydroxyapatite nanopowders by sol–gel emulsion ...

    Indian Academy of Sciences (India)

    Administrator

    volume% of surfactant (Span 80), followed by the addition of triethylamine, for gelation. The gel powders thus obtained were calcined at different temperatures up to 750°C. Characterization was done using XRD,. SEM and TEM. Pellets were made from the developed HAP powders and tested for its biocompatibility after.

  17. Poly(vinyl alcohol) gels as photoacoustic breast phantoms revisited

    NARCIS (Netherlands)

    Xia, W.; Piras, D.; Heijblom, M.; Steenbergen, Wiendelt; van Leeuwen, Ton; Manohar, Srirang

    2011-01-01

    A popular phantom in photoacoustic imaging is poly(vinyl alcohol) (PVA) hydrogel fabricated by freezing and thawing (F–T) aqueous solutions of PVA. The material possesses acoustic and optical properties similar to those of tissue. Earlier work characterized PVA gels in small test specimens where

  18. Poly(vinyl alcohol) gels as photoacoustic breast phantoms revisited

    NARCIS (Netherlands)

    Xia, Wenfeng; Piras, Daniele; Heijblom, Michelle; Steenbergen, Wiendelt; van Leeuwen, Ton G.; Manohar, Srirang

    2011-01-01

    A popular phantom in photoacoustic imaging is poly(vinyl alcohol) (PVA) hydrogel fabricated by freezing and thawing (F-T) aqueous solutions of PVA. The material possesses acoustic and optical properties similar to those of tissue. Earlier work characterized PVA gels in small test specimens where

  19. Fluorine profiling after application of various anti-caries gels

    International Nuclear Information System (INIS)

    Zschau, H.E.; Plier, F.; Otto, G.; Wyrwich, C.; Treide, A.

    1990-01-01

    Two newly developed caries-preventing gels were tested together with Elmex on pre-school children over a time of 3 years. Proton-induced gamma-ray emission spectrometry (PIGE) was used to measure the fluorine profiles in milk teeth (incisors). In accordance with the clinical statement the results allow to produce a new anti-caries drug. (orig.)

  20. Growth of strontium oxalate crystals in agar–agar gel

    Indian Academy of Sciences (India)

    single diffusion technique in which the gel medium does. Figure 4. a. Transparent prismatic bi-pyramidal platy shaped crystals at interstitial and spherulite crystals well inside test-tube using NH4Cl additive in single diffusion and b. some good quality crystals obtained using NH4Cl as addictive in single diffusion.

  1. Cumulative irritation potential among metronidazole gel 1%, metronidazole gel 0.75%, and azelaic acid gel 15%.

    Science.gov (United States)

    Colón, Luz E; Johnson, Lori A; Gottschalk, Ronald W

    2007-04-01

    Topical therapy for rosacea aims to reduce inflammatory lesions and decrease erythema but can carry side effects such as stinging, pruritus, and burning. Metronidazole and azelaic acid gel 15% are U.S. Food and Drug Administration-approved for the treatment of rosacea. The current study was conducted to assess the cumulative irritation potential of 2 formulations of metronidazole 0.75% gel and 1% gel--and azelaic acid gel 15% over 21 days (N=36). Results of this study demonstrated a significantly greater poten tial for irritation from azelaic acid compared with metronidazole gel 0.75% (P < .0001), which had significantly greater potential for irritation compared with metronidazole gel 1% (P = .0054). Metronidazole gel 1% had a similar profile to white petrolatum.

  2. Comparative gel electrophoresis analysis of helical junctions in RNA.

    Science.gov (United States)

    Lilley, David M J

    2009-01-01

    Comparative gel electrophoresis provides information on the relative angles subtended between helical arms at a branchpoint in RNA. It is based upon the comparison of electrophoretic mobility in polyacrylamide gels of species containing two long arms, with the remaining one(s) being significantly shorter. Although the method currently lacks a really well-established basis of physical theory, it is very powerful, yet simple to apply. It has had a number of significant successes in RNA, DNA and DNA-protein complexes, and in all cases to date the results have stood the test of time and eventual comparison with crystallographic analysis. Copyright © 2009 Elsevier Inc. All rights reserved.

  3. Scaffold architecture and fibrin gels promote meniscal cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Pawelec, K. M., E-mail: pawelec.km@gmail.com, E-mail: jw626@cam.ac.uk; Best, S. M.; Cameron, R. E. [Cambridge Centre for Medical Materials, Materials Science and Metallurgy Department, University of Cambridge, Cambridge CB3 0FS (United Kingdom); Wardale, R. J., E-mail: pawelec.km@gmail.com, E-mail: jw626@cam.ac.uk [Division of Trauma and Orthopaedic Surgery, Department of Surgery, University of Cambridge, Cambridge CB2 2QQ (United Kingdom)

    2015-01-01

    Stability of the knee relies on the meniscus, a complex connective tissue with poor healing ability. Current meniscal tissue engineering is inadequate, as the signals for increasing meniscal cell proliferation have not been established. In this study, collagen scaffold structure, isotropic or aligned, and fibrin gel addition were tested. Metabolic activity was promoted by fibrin addition. Cellular proliferation, however, was significantly increased by both aligned architectures and fibrin addition. None of the constructs impaired collagen type I production or triggered adverse inflammatory responses. It was demonstrated that both fibrin gel addition and optimized scaffold architecture effectively promote meniscal cell proliferation.

  4. Nanocrystal/sol-gel nanocomposites

    Science.gov (United States)

    Klimov, Victor L.; Petruska, Melissa A.

    2010-05-25

    The present invention is directed to a process for preparing a solid composite having colloidal nanocrystals dispersed within a sol-gel matrix, the process including admixing colloidal nanocrystals with an amphiphilic polymer including hydrophilic groups selected from the group consisting of --COOH, --OH, --SO.sub.3H, --NH.sub.2, and --PO.sub.3H.sub.2 within a solvent to form an alcohol-soluble colloidal nanocrystal-polymer complex, admixing the alcohol-soluble colloidal nanocrystal-polymer complex and a sol-gel precursor material, and, forming the solid composite from the admixture. The present invention is also directed to the resultant solid composites and to the alcohol-soluble colloidal nanocrystal-polymer complexes.

  5. Dosimetry for computed tomography using Fricke gel dosimetry and magnetic resonance imaging; Dosimetria em tomografia computadorizada empregando dosimetro Fricke gel e a tecnica de imageamento por ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Capeleti, Felipe Favaro; Campos, Leticia L., E-mail: felipe@gmpbrasil.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2014-04-15

    In this work it was determined a new method for the determination of absorbed doses in Computed Tomography (CT) examinations using Fricke gel dosimetry developed at IPEN. Absorbed doses were determined by different methods of analysis, such as optical absorption spectrometry, ionization chambers and magnetic resonance imaging. Lower limit of sensitivity of the Fricke gel solution, the solution repeatability signal Fricke gel and CT equipment, detection sensitivity, among other tests were performed. Different equipment of computed tomography with multiple detectors were used. The Fricke gel solution showed better repeatability than ±5.5% using the technique of optical absorption spectrophotometry and computed tomography equipment showed repeatability better than ±0.2%. The Fricke gel solution features an easy and relatively quick preparation, but it is necessary to be careful not to contaminate and lose the solution. With the results, it was confirmed the application of this type of dosimetry for computed tomography equipment. (author)

  6. Nanoparticles laden in situ gel for sustained ocular drug delivery

    Directory of Open Access Journals (Sweden)

    Himanshu Gupta

    2013-01-01

    Full Text Available Proper availability of drug on to corneal surface is a challenging task. However, due to ocular physiological barriers, conventional eye drops display poor ocular bioavailability of drugs (< 1%. To improve precorneal residence time and ocular penetration, earlier our group developed and evaluated in situ gel and nanoparticles for ocular delivery. In interest to evaluate the combined effect of in situ gel and nanoparticles on ocular retention, we combined them. We are the first to term this combination as "nanoparticle laden in situ gel", that is, poly lactic co glycolic acid nanoparticle incorporated in chitosan in situ gel for sparfloxacin ophthalmic delivery. The formulation was tested for various physicochemical properties. It showed gelation pH near pH 7.2. The observation of acquired gamma camera images showed good retention over the entire precorneal area for sparfloxacin nanoparticle laden in situ gel (SNG as compared to marketed formulation. SNG formulation cleared at a very slow rate and remained at corneal surface for longer duration as no radioactivity was observed in systemic circulation. The developed formulation was found to be better in combination and can go up to the clinical evaluation and application.

  7. Microphase separation in nanocomposite gels

    Science.gov (United States)

    Osaka, Noboru; Endo, Hitoshi; Nishida, Toshihiko; Suzuki, Takuya; Li, Huan-Jun; Haraguchi, Kazutoshi; Shibayama, Mitsuhiro

    2009-06-01

    Microphase separation in poly( N -isopropylacrylamide)(PNIPA)-clay nanocomposite hydrogels (NC gels) is investigated by means of contrast-variation small-angle neutron scattering (CV-SANS) and dynamic light scattering (DLS). By using CV-SANS, it is revealed that microphase separation occurs in NC gels above the lower-critical solution temperature (LCST) of PNIPA aqueous solutions. The observed partial scattering functions show that only the spatial distribution of PNIPA chains is highly distorted by microphase separation and PNIPA chains are preferentially adsorbed on the clay surfaces, where the PNIPA-rich phase forms nanoscaled bicontinuous structure mediated by the clay particles. Additional DLS measurements for dilute solutions with PNIPA and/or the clay nanoparticles confirm that aggregation of PNIPA above the LCST is dramatically suppressed by addition of clay particles. Based on these observations, we conclude that strong affinity between the polymer and clay has a significant effect on the phase separation in NC gels and allows one to tune the length scale of the phase separation phenomenon by clay concentration.

  8. Rapid high voltage isoelectric focusing of proteins in rod gels.

    Science.gov (United States)

    Das, J

    1991-09-01

    A rapid procedure of isoelectric focusing (IEF) of proteins in polyacrylamide rod gels (i.d., 1.1 mm; length, 7.5 cm) is described. The time required for IEF can be reduced to 0.5 h by using high voltages up to 3000 V in the presence or absence of urea in the gels. When used as the first dimension of a two-dimensional technique for IEF sodium dodecyl sulphate electrophoresis, high voltage IEF gives smaller protein spots on the second dimension gel, associated with an increase in resolution. The method has been tested by a two-dimensional separation of an eye sample of the goodeid fish Xenotoca eiseni.

  9. Development of gel materials with high transparency and mechanical strength for use with a 3D gel printer SWIM-ER

    Science.gov (United States)

    Tase, Taishi; Okada, Koji; Takamatsu, Kyuichiro; Saito, Azusa; Kawakami, Masaru; Furukawa, Hidemitsu

    2016-04-01

    Medical doctors use artificial blood vessels and organ models, which are usually made of plastic, to explain operations to students, or patients awaiting treatment. However, there are some problems such as the high cost of making the model and there is not a realistic feel because the model is hard. These problems can be solved using soft and wet material for instance gel. Gels are materials with unique properties such as transparency, biocompatibility, and low friction. In recent years, high strength gel has been developed and is expected to be applied in medical fields in the future. Artificial models of gel can be produced by 3D gel printers. Our group has been developing a 3D gel printer with 1mm precision in printing, but the shape, size and mechanical strength are not sufficient for medical models. In this study, we overcome these problems and make a gel model which is transparent, mechanically strong with a fine shape. The strength and molding accuracy is improved by changing and preparing the cross linker and ultraviolet absorber. We conducted mechanical and molding tests to confirm that the gel material properties improved.

  10. Water equivalence of polymer gel dosimeters

    International Nuclear Information System (INIS)

    Sellakumar, P.; James Jebaseelan Samuel, E.; Supe, Sanjay S.

    2007-01-01

    To evaluate the water equivalence and radiation transport properties of polymer gel dosimeters over the wide range of photon and electron energies 14 different types of polymer gels were considered. Their water equivalence was evaluated in terms of effective atomic number (Z eff ), electron density (ρ e ), photon mass attenuation coefficient (μ/ρ), photon mass energy absorption coefficient (μ en /ρ) and total stopping power (S/ρ) tot of electrons using the XCOM and the ESTAR database. The study showed that the effective atomic number of polymer gels were very close ( en /ρ for all polymer gels were in close agreement ( tot of electrons in polymer gel dosimeters were within 1% agreement with that of water. From the study we conclude that at lower energy (<80keV) the polymer gel dosimeters cannot be considered water equivalent and study has to be carried out before using the polymer gel for clinical application

  11. 3D jet printer of edible gels for food creation

    Science.gov (United States)

    Serizawa, Ryo; Shitara, Mariko; Gong, Jin; Makino, Masato; Kabir, M. Hasnat; Furukawa, Hidemitsu

    2014-03-01

    In recent years, aging is progressing in Japan. Elderly people can't swallow the food well. So, the need of soft food is increasing greatly with the aging of the population. There are so few satisfying foods for the elderly to enjoy a meal. An equipment of printing soft food gives the elderly a big dream and is promising. In this study, we aim at developing a 3D edible gel printer in order to make soft food for the elderly. We made a prototype of the 3D edible gel printer. The printer consists of syringe pump and dispenser. The syringe pump extrudes the solution. The dispenser allows to model threedimensional objects. We use agar solution as the ink to carry out the printing. Agar's gelation deeply depends on temperature. Therefore temperature control of the solution is important to mold optimal shapes because the physical crosslinking network of agar's solution is instable. We succeeded in making the gels and plate-shape gel using the 3D edible gel printer. Further more, in order to increase the gelation speed agar's solution, we changed the dispenser and the printing test is being done now. 4 kinds of soft food prepared from agar and gelatin were printed by the 3D edible gel printer. The compression tests of the printed soft food samples were done and their hardness is measured because the hardness is one of very important factors which influence the food texture greatly. In the future, the viscosity of the agar solution or other food ink should be adjusted to suitable for printing.

  12. Aspects of dosimetry using radiation sensitive gels

    International Nuclear Information System (INIS)

    Baldock, Clive

    2001-01-01

    The use of radiation sensitive gels for dosimetry measurements was first suggested in the 1950s. It was subsequently shown that radiation induced changes in nuclear magnetic resonance (NMR) relaxation properties of gels infused with conventional Fricke dosimetry solutions could be measured. However, due to predominantly diffusion-related limitations, alternative polymer gel dosimeters were suggested. Clinical applications of these radiologically tissue equivalent gel dosimeters using magnetic resonance imaging (MRI) have subsequently been reported in the literature. In Fricke gels, Fe 2+ ions in ferrous sulphate solutions are usually dispersed throughout a gelatin or agarose hydrogel matrix. Radiation-induced changes in the dosimeters are considered to be either through direct absorption of ionising radiation or via intermediate water free radicals. Fe 2+ ions are converted to Fe 3+ ions with a corresponding change in paramagnetic properties that may be quantified using NMR relaxation measurements. In polymer gels, monomers are also dispersed in a gelatin or agarose hydrogel matrix. Monomers undergo a polymerisation reaction as a function of absorbed dose resulting in a three-dimensional polymer gel matrix. The radiation-induced formation of polymer influences NMR relaxation properties. The growth in polymer also results in other physical changes that may be used to quantify absorbed radiation dose. This thesis investigates various aspects of radiation dosimetry using radiation sensitive gels. Image processing software was developed to calculate NMR relaxation images of dosimetry gels. Measurements were undertaken to investigate the diffusion problem in Fricke gels. Radiological properties were theoretically modelled for both Fricke and polymer gels. A methodology was developed for the preparation of polymer gels. Vibrational spectroscopic studies were undertaken to investigate the underlying mechanism involved in the radiation-induced formation of polymer. MRI

  13. Effect of Proteolytic Modification on Texture and Mastication of Heat-Treated Egg White Gels.

    Science.gov (United States)

    Funaki, Junko; Minami, Michiko; Abe, Sachie; Ueda, Reiko; Eto, Wakako; Kugino, Kenji; Kugino, Mutsuko; Abe, Keiko; Toko, Kiyoshi; Asakura, Tomiko

    2017-02-01

    Raw egg white undergoes sol-gel transition by heat treatment, which changes it to an elastic gel. Here, protease treatment to render a new texture to heated egg white gel was applied. Protease-treated gels exhibited ductile flow without obvious rupture points. Transmission electron microscopy analysis showed that in protease-treated gels, protein aggregates were distributed more homogeneously compared with that observed in the untreated control, probably because ovalbumin was digested into small peptides as revealed by SDS-PAGE. The properties of the gel were evaluated by sensory tests and by measuring the movement of the masseter muscle, using surface electromyography. Results showed that maximum bite force and mastication duration were decreased for the protease-treated gels, which were evaluated as being softer, smoother, less elastic and better textured. Overall, our results indicate that protease-treated egg white gel has superior qualities and is easier to swallow than the untreated gel. In the food industry, the use of egg white is limited compared with that of egg yolk and whole eggs. In this study, we performed protease treatment to generate a new food material with smoother and softer texture compared with heat treated egg white. Our findings may expand the consumption of egg white, which can be consumed by people with mastication and swallowing disorders, and reduce the waste of egg white as a surplus product.

  14. Type I collagen gel protects murine fibrosarcoma L929 cells from TNFα-induced cell death

    International Nuclear Information System (INIS)

    Wang, Hong-Ju; He, Wen-Qi; Chen, Ling; Liu, Wei-Wei; Xu, Qian; Xia, Ming-Yu; Hayashi, Toshihiko; Fujisaki, Hitomi; Hattori, Shunji; Tashiro, Shin-ichi; Onodera, Satoshi; Ikejima, Takashi

    2015-01-01

    Murine fibrosarcoma L929 cells have been used to test efficacy of proinflammatory cytokine TNFα. In the present study, we reported on protective effect of type I collagen gel used as L929 cell culture. L929 cell grew and proliferated well on collagen gel. However, the L929 cells exhibited cobblestone-like morphology which was much different from the spread fusiform shape when cultured on conventional cell dishes as well as the cells tended to aggregate. On conventional cell culture dishes, the cells treated with TNFα became round in shape and eventually died in a necroptotic manner. The cells cultured on collagen gel, however, were completely unaffected. TNFα treatment was reported to induce autophagy in L929 cells on the plastic dish, and therefore we investigated the effect of collagen gel on induction of autophagy. The results indicated that autophagy induced by TNFα treatment was much reduced when the cells were cultured on collagen gel. In conclusion, type I collagen gel protected L929 cell from TNFα-induced cell death. - Highlights: • Collagen gel culture changed the morphology of L929 cells. • L929 cell cultured on collagen gel were resistant to TNFα-induced cell death. • Collagen gel culture inhibited TNFα-induced autophagy in L929 cells

  15. Characterization of spreadability of nonaqueous ethylcellulose gel matrices using dynamic contact angle.

    Science.gov (United States)

    Chow, Keat Theng; Chan, Lai Wah; Heng, Paul W S

    2008-08-01

    This study reports the characterization of spreadability of nonaqueous ethylcellulose (EC) gel matrices intended for topical drug delivery using a newly developed method based on dynamic contact angle. EC solutions were prepared using three grades of EC and propylene glycol dicaprylate/dicaprate. Dynamic contact angles of sessile drops of EC solutions on silicone elastomer were measured using a dynamic contact angle analyzer equipped with axisymmetric drop shape analysis-profile. Roughness of silicone elastomer, viscosity of EC solutions and compressibility of semisolid EC gels were determined by the atomic force microscope, cone-and-plate rheometer and tensile tester, respectively. The silicone elastomer employed as a substrate was demonstrated to have similar hydrophilic/lipophilic properties as the human skin. Spreadability of EC solutions was dependent on EC concentration, polymeric chain length and polydispersity. EC gel spreadability was governed by viscosity and the extent of gel-substrate interaction. From the apparent contact angle values, most EC gel formulations tested were found to be moderately spreadable. Linear correlation observed between spreading parameter and compressibility of EC gel verified the applicability of dynamic contact angle to characterize EC gel spreadability. Thus, the feasibility of employing dynamic contact angle as an alternative technique to measure gel spreadability was demonstrated. The spreadability demonstrated by EC gel would facilitate application on the skin indicating its potential usefulness as a topical dosage form.

  16. Synthesis of organic/inorganic hybrid gel with acid activated clay after γ-ray radiation.

    Science.gov (United States)

    Kim, Donghyun; Lee, Hoik; Sohn, Daewon

    2014-08-01

    A hybrid gel was prepared from acid activated clay (AA clay) and acrylic acid by gamma ray irradiation. Irradiated inorganic particles which have peroxide groups act as initiator because it generates oxide radicals by increasing temperature. Inorganic nanoparticles which are rigid part in hybrid gel also contribute to increase the mechanical property as a crosslinker. We prepared two hybrid gels to compare the effect of acid activated treatment of clay; one is synthesized with raw clay particles and another is synthesized with AA clay particles. The composition and structure of AA clay particles and raw clay particles were confirmed by X-ray diffraction (XRD), X-ray fluorescence instrument and surface area analyzer. And chemical and physical property of hybrid gel with different ratios of acrylic acid and clay particle was tested by Raman spectroscope and universal testing machine (UTM). The synthesized hydrogel with 76% gel contents can elongated approximately 1000% of its original size.

  17. An in vitro comparative evaluation of the antibacterial efficacy of 10% metronidazole gel, 2% chlorhexidine gel, and a combination of calcium hydroxide and 2% chlorhexidine gel against Enterococcus faecalis

    Directory of Open Access Journals (Sweden)

    Jaya Nagendra Krishna

    2012-01-01

    statistical analysis using the Mann-Whitney test and the χ2 test. Results: In our study, Group II (2% CHX gel showed significant reduction of E. faecalis. Group I (10% metronidazole gel showed minimal -reduction, and Group III (2% CHX gel with calcium hydroxide showed moderate -reduction. There was no -reduction in observed in Group IV (control group patients. Conclusion: Our study -signifies that 2% CHX gel showed substantial antimicrobial activity against E. faecalis. The -combination of calcium hydroxide and 2% CHX gel also showed good -antimicrobial activity. Hence, the efficacy of 2% CHX gel was greater than its -combination with -calcium hydroxide. The least effective drug against the microbes was metronidazole.

  18. Rheological characterization of Poloxamer 407 nimesulide gels

    Directory of Open Access Journals (Sweden)

    M. N. Freitas

    2009-01-01

    Full Text Available The thermal gelling property of Poloxamer 407- nimesulide gels was characterized by rheological studies. Nimesulide, a local anti-inflammatory and anesthetic drug used for the treatment of acute and chronic pain, has a short duration of action and a long-acting single-dose injection would be of clinical importance. Thus a poloxamer 407 gel applied intramuscularly could prolong the release and action of nimesulide. In this study, aqueous gels with nimesulide, containing three different concentrations of Poloxamer 407, were prepared. Viscosity measurements were performed by rheologial studies to obtain the optimal sol-gel transition temperature . Poloxamer 407 gels are pseudoplastic and viscoelastic materials, which have an elastic modulus (G', characteristic of the solid, and a viscous modulus (G'', characteristic of the liquid material. Moreover, being pseudoplastic gels, when they are deformed by shearing, their viscosity decreases. Increase of the polymer concentration increased the viscosity of the gels, which could affect the releasing process of nimesulide. Furthermore, the presence of nimesulide led to a lowering of the sol-gel transition temperature. Keywords: Poloxamer 407 gels; nimesulide; rheological characterization; viscosity; sol-gel transition temperature.

  19. Characterization and Biocompatibility of Chitosan Gels with Silver and Gold Nanoparticles

    Directory of Open Access Journals (Sweden)

    C. Sámano-Valencia

    2014-01-01

    Full Text Available The presence of bacterial resistance to antibiotics is a very important issue and the search of new alternatives is necessary. In this work, a combination of chitosan gel with silver or gold nanoparticles was prepared and characterized using thermal, rheology, bactericide, and biocompatibility analyses. ESEM images were also taken to visualize the incorporation of the nanoparticles into the gel matrix. Thermal analysis showed a better thermal stability in the chitosan-gold nanoparticles gels compared to the chitosan-silver nanoparticles gels. Rheology analyses showed that the viscosity of the gels decreased when velocity increased and there were differences in viscosity when silver and gold nanoparticles concentrations change. ESEM images showed the presence of agglomerates of silver and gold nanoparticles into the gel matrix with a good distribution; in some cases the formation of microstructures was found. Bactericide results show that these materials present an antibacterial activity against S. aureus, S. mutans, and E. coli. The biocompatibility test showed neither negative reaction nor wound healing delay after the application of the gels in an in vivo test. The gels with silver and gold nanoparticles could be used to treat wound infections in oral or skin applications.

  20. The characteristics of bacterial nanocellulose gel releasing silk sericin for facial treatment.

    Science.gov (United States)

    Aramwit, Pornanong; Bang, Nipaporn

    2014-12-09

    Recently, naturally derived facial masks with beneficial biological properties have received increasing interest. In this study, silk sericin-releasing bacterial nanocellulose gel was developed to be applied as a bioactive mask for facial treatment. The silk sericin-releasing bacterial nanocellulose gel produced at a pH of 4.5 had an ultrafine and extremely pure fiber network structure. The mechanical properties and moisture absorption ability of the gel were improved, compared to those of the commercially available paper mask. Silk sericin could be control-released from the gel. A peel test with porcine skin showed that the gel was less adhesive than the commercially available paper mask, which would be removed from the face more easily without pain. The in vitro cytotoxicity test showed that the gel was not toxic to L929 mouse fibroblast and HaCaT human keratinocyte cells. Furthermore, when implanted subcutaneously and evaluated according to ISO10993-6 standard, the gel was not irritant to tissue. The silk sericin-releasing bacterial nanocellulose gel had appropriate physical and biological properties and safety for the facial treatment application.

  1. An outbreak of infectious bursal disease in eight weeks old IBD ...

    African Journals Online (AJOL)

    An outbreak of infectious bursal disease (IBD) on an IBD vaccinated commercial poultry farm was investigated using clinical and pathological findings as well as antigen and antibody detection by agar gel immunodiffusion test (AGDT). Mortality was observed 3 days after the onset of clinical signs and peaked on day 5 but ...

  2. Cervical ripening with prostaglandin gel and hygroscopic dilators.

    Science.gov (United States)

    Hibbard, J U; Shashoua, A; Adamczyk, C; Ismail, M

    1998-01-01

    OBJECTIVE: To study the effectiveness and morbidity of adding hygroscopic cervical dilators to prostaglandin gel for cervical ripening and labor induction. STUDY DESIGN: Patients of at least 34 weeks' gestation with a medical indication for induction of labor and with a modified Bishop score of 5 or less were randomized to receive either prostaglandin gel or prostaglandin gel with hygroscopic cervical dilators. Primary outcomes were time to delivery, change in cervical score, and infection. Secondary outcomes included cesarean delivery rate and deliveries before 24 hours of induction. Continuous variables were analyzed by Wilcoxon sum rank test and categorical data by chi-square or Fisher exact test, with P intracervical prostaglandin alone and 23 patients received intracervical prostaglandin plus hygroscopic dilators. No demographic differences were noted between the groups. After six hours of ripening, the combined group achieved a greater change in Bishop score (3.6 vs. 2.1, P = 0.007) and tended to have a shorter induction time (21.7 vs. 26.4 hours, P = 0.085). The combined therapy group had a higher infection rate than the prostaglandin-only group (59% vs. 12%, P = 0.003). CONCLUSION: Combining cervical dilators with prostaglandin gel provides more effective cervical ripening and a more rapid induction to delivery interval than prostaglandin alone but with a significant and prohibitive rate of infection. PMID:9678143

  3. Electrically controllable ionic polymeric gels as adaptive optical lenses

    Science.gov (United States)

    Salehpoor, Karim; Shahinpoor, Mohsen; Mojarrad, Mehran

    1996-02-01

    Reversible change in optical properties of ionic polymeric gels, 2-acrylamido-2-methylpropane sulfonic acid (PAMPS) and polyacrylic acid plus sodium acrylate cross-linked with bisacrylamide (PAAM), under the effect of an electric field is reported. The shape of a cylindrical piece of the gel, with flat top and bottom surfaces, changed when affected by an electric field. The top surface became curved and the sense of the curvature (whether concave or convex) depended on the polarity of the applied electric field. The curvature of the surface changed from concave to convex and vice versa by changing the polarity of the electric field. By the use of an optical apparatus, focusing capability of the curved surface was verified and the focal length of the deformed gel was measured. The effect of the intensity of the applied electric field on the surface curvature and thus, on the focal length of the gel are tested. Different mechanisms are discussed; either of them or their combination may explain the surface deformation and curvature. Practical difficulties in the test procedure and the future potential of the electrically adaptive and active optical lenses are also discussed. These adaptive lenses may be considered as smart adaptive lenses for contact lens or other optical applications requiring focal point undulation.

  4. Effect of 10% papain gel on enamel deproteinization before bonding procedure.

    Science.gov (United States)

    Pithon, Matheus Melo; Ferraz, Caio de Souza; de Oliveira, Gabriel do Couto; Pereira, Tatiana Bahia Junqueira; Oliveira, Dauro Douglas; de Souza, Ricardo Alves; de Freitas, Lívia Maria Andrade; dos Santos, Rogério Lacerda

    2012-05-01

    To test the null hypothesis that enamel deproteinization with 10% papain gel does not increase the shear bond strength of orthodontic brackets bonded with resin-modified glass ionomer cement (RMGIC). One hundred and twenty bovine incisors were used and divided into eight groups: 1) Transbond XT according to the manufacturer's recommendations, 2) Transbond XT deproteinized with 10% papain gel, 3) RMGIC without enamel deproteinization and without etching, 4) RMGIC without enamel etching and with deproteinization with 10% papain gel, 5) RMGIC deproteinized with 10% papain gel and etched with polyacrylic acid, 6) RMGIC deproteinized with 10% papain gel and etched with phosphoric acid, 7) RMGIC deproteinized with 2.5% sodium hypochlorite, and 8) RMGIC etched with polyacrylic acid. After bonding, the mechanical tests were performed in a Universal mechanical test machine. The values obtained were submitted to an analysis of variance and afterward to the Tukey test (P enamel deproteinization with 10% papain gel increases the shear bond strength, irrespective of the etching agent. The hypothesis is rejected. Papain gel was shown to be a new ally in the orthodontic clinic.

  5. Calcium Impact on Milk Gels Formation

    DEFF Research Database (Denmark)

    Koutina, Glykeria

    salts. The perturbation of calcium equilibria by these factors will affect the final properties of acid, calcium and rennet milk gels. By decreasing the pH from 6.0 to 5.2 (acid gels), the calcium equilibrium was significantly affected by temperature (4, 20, 30, 40 oC), and different combinations...... enriched dairy products. Calcium gels can be produced by addition of a calcium salt and heat treatment at temperatures higher than 70 oC for several minutes. The combination of heat treatment and calcium addition to milk with pH values between 6.6 and 5.6, will produce calcium milk gels with unique...... to be formed. In addition the low amount of micellar calcium caused a more compact gel structure with many protein aggregates. The results of this study highlighted the importance of calcium for the formation of acid, calcium and rennet gels. The content and the interactions of calcium with proteins during...

  6. Research on pre-staining gel electrophoresis

    International Nuclear Information System (INIS)

    Zhong Ruibo; Liu Yushuang; Zhang Ping; Liu Jingran; Zhao Guofen; Zhang Feng

    2014-01-01

    Background: Gel electrophoresis is a powerful biochemical separation technique. Most biological molecules are completely transparent in the visible region of light, so it is necessary to use staining to show the results after gel electrophoresis, and the general steps of conventional staining methods are time-consuming. Purpose: We try to develop a novel approach to simplify the gel electrophoresis: Pre-Staining Gel Electrophoresis (PSGE), which can make the gel electrophoresis results monitored in real time. Methods: Pre-stain the protein samples with Coomassie Brilliant Blue (CBB) for 30 min before loading the sample into the gel well. Results and Conclusion: PSGE can be successfully used to analyze the binding efficiency of Bovine Serum Albumin (BSA) and amphiphilic polymer via chemical coupling and physical absorption, and the double PSGE also shows a great potential in bio-analytical chemistry. (authors)

  7. EKSTRAK BAWANG PUTIH (Allium sativum L SEBAGAI ZAT AKTIF PADA FORMULASI SEDIAAN GEL

    Directory of Open Access Journals (Sweden)

    Densi Selpia Sopianti

    2018-03-01

    Full Text Available Garlic (Allium sativum L has a nickname as a natural antibiotic. Application of garlic on the face also has several benefits that can cure acne (acne vulgaris. The purpose of this research is to make gel preparation as active substance that is used garlic extract (Allium sativum L. Methods in laboratory experimental research, in which garlic as an active ingredient is extracted using maseration method. Three variants of the preparation formulation were 3%, 5%, and 7% and other additives in gel preparation using Na.CMC, nipagin and nipasol, glycerol and olium guajava. Each gel formula was evaluated for the preparation including organoleptis, homogeneity, pH test, spreading test, and irritation test. The result of evaluation of gel physical properties of the three formulas with variation of garlic extract at different concentrations produced formula I with concentration of garlic extract 3% yielded better test than Formula II and formula III.

  8. Test

    DEFF Research Database (Denmark)

    Bendixen, Carsten

    2014-01-01

    Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers.......Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers....

  9. Self-Pumping Active Gel

    Science.gov (United States)

    Wu, Kun-Ta; Hishamunda, Jean Bernard; Fraden, Seth; Dogic, Zvonimir

    Isotropic active gels are the network which is consist of cross-linked building blocks and the structure of which changes randomly and isotropically with time. Dogic et. al. show that pairs of anti-parallel microtubules form extensile bundles, which merge, extend, and buckle. In an unconfined system, the dynamics of these bundles causes spontaneous turbulent-like flow driven by motion of microscopic molecular motors. We found that confining these active gels in a millimeter sized toroids causes a transition into a new dynamical state characterized by circulation currents persisting for hours until ATP is depleted. We show how toroid dimensions impact the properties of self-organized circular currents, how directions of circulation can be designed by engineering ratchet-shaped boundaries, and how circulations of connected toroids can be either synchronized or antisynchronized. Furthermore, we demonstrate that the flow rate in the circulation is independent of curvature and length of flow path. The flow rate persists for centimeters without decay, disregarding conventional pipe flow resistance. Such findings pave the path to self-pumping pipe transport and performing physical work with biological system.

  10. Microfluidics of soft granular gels

    Science.gov (United States)

    Nixon, Ryan; Bhattacharjee, Tapomoy; Sawyer, W. Gregory; Angelini, Thomas E.

    Microfluidic methods for encapsulating cells and particles typically involve drop making with two immiscible fluids. The main materials constraint in this approach is surface tension, creating inherent instability between the two fluids. We can eliminate this instability by using miscible inner and outer phases. This is achieved by using granular micro gels which are chemically miscible but physically do not mix. These microgels are yield stress materials, so they flow as solid plugs far from shear gradients, and fluidize where gradients are generated - near an injection nozzle for example. We have found that tuning the yield stress of the material by varying polymer concentration, device performance can be controlled. The solid like behavior of the gel allows us to produces infinitely stable jets that maintain their integrity and configuration over long distances and times. These properties can be combined and manipulated to produce discrete particulate bunches of an inner phase, flowing inside of an outer phase, well enough even to print a Morse code message suspended within flow chambers about a millimeter in diameter moving at millimeters a second.

  11. The application of sol-gel and gel-precipitation technology to the preparation of spheres of lithium aluminate

    International Nuclear Information System (INIS)

    Turner, C.W.; Clatworthy, B.C.

    1988-01-01

    A concept for preparing spheres of lithium aluminate by either a sol-gel or gel-precipitation process based on the precipitation of a lithium salt in the pores of an aluminum hydroxide gel has been tested and has proved to be not feasible. The addition of any of the following salts: lithium formate; lithium oxalate; or lithium carbonate to a solution of aluminum nitrate hydrolysed to a hydroxyl number greater than 2.85 caused the hydrolysed solution, or sol, to gel immediately. The addition of lithium formate to a dialysed sol caused it to flocculate at low pH and prevented the transformation from a sol to a gel from occurring at elevated pH. This behaviour was linked to the adsorption of the anions - formate, oxalate, or carbonate - onto the surface of the sol particles. Hydrolysis of solutions of aluminum nitrate together with either lithium formate, lithium oxalate, or lithium carbonate, such that the mole ratio of aluminum to lithium was 1:1, resulted in the formation of a crystalline precipitate containing both lithium and aluminum. The lithium to aluminum ratio of the precipitate was 0.44:1 when lithium was introduced as the carbonate. Spheres could be made by gel-precipitation if the viscosity of the feed solution was first increased to 200 cps by the addition of polyvinyl alcohol. However, the lithium not chemically bound in the precipitate diffused out of the spheres during gelation. Heating of the lithium-deficient spheres to 950 degrees C produced a mixture of lithium aluminate and the spinel phase, LiAl 5 O 8

  12. Stabilized aqueous gels and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Swanson, B.L.

    1978-08-29

    New improved aqueous gels, and methods of using same in contacting subterranean formations, are provided. The gels are prepared by gelling an aqueous brine having incorporated therein a water-soluble cellulose ether such as a carboxymethylcellulose (CMC), and are rendered more stable to decomposition by incorporating a sulfoalkylated tannin stabilizing agent, such as a sulfomethylated quebracho (SMQ), in the gel during the preparation thereof.

  13. Ionic liquid based multifunctional double network gel

    Science.gov (United States)

    Ahmed, Kumkum; Higashihara, Tomoya; Arafune, Hiroyuki; Kamijo, Toshio; Morinaga, Takashi; Sato, Takaya; Furukawa, Hidemitsu

    2015-04-01

    Gels are a promising class of soft and wet materials with diverse application in tissue engineering and bio-medical purpose. In order to accelerate the development of gels, it is required to synthesize multi-functional gels of high mechanical strength, ultra low surface friction and suitable elastic modulus with a variety of methods and new materials. Among many types of gel ionic gel made from ionic liquids (ILs) could be used for diverse applications in electrochemical devices and in the field of tribology. IL, a promising materials for lubrication, is a salt with a melting point lower than 100 °C. As a lubricant, ILs are characterized by an extremely low vapor pressure, high thermal stability and high ion conductivity. In this work a novel approach of making double network DN ionic gel using IL has been made utilizing photo polymerization process. A hydrophobic monomer Methyl methacrylate (MMA) has been used as a first network and a hydrophobic IL monomer, N,N-diethyl-N-(2-mthacryloylethyl)-N-methylammonium bistrifluoromethylsulfonyl)imide (DEMM-TFSI) has been used as a second network using photo initiator benzophenon and crosslinker triethylene glycol dimethacrylate (TEGDMA). The resulting DN ionic gel shows transparency, flexibility, high thermal stability, good mechanical toughness and low friction coefficient value which can be a potential candidate as a gel slider in different mechanical devices and can open a new area in the field of gel tribology.

  14. Gel catalysts that switch on and off

    Science.gov (United States)

    Wang, Guoqiang; Kuroda, Kenichi; Enoki, Takashi; Grosberg, Alexander; Masamune, Satoru; Oya, Taro; Takeoka, Yukikazu; Tanaka, Toyoichi

    2000-01-01

    We report development of a polymer gel with a catalytic activity that can be switched on and off when the solvent composition is changed. The gel consists of two species of monomers. The major component, N-isopropylacrylamide, makes the gel swell and shrink in response to a change in composition of ethanol/water mixtures. The minor component, vinylimidazole, which is capable of catalysis, is copolymerized into the gel network. The reaction rate for catalytic hydrolysis of p-nitrophenyl caprylate was small when the gel was swollen. In contrast, when the gel was shrunken, the reaction rate increased 5 times. The activity changes discontinuously as a function of solvent composition, thus the catalysis can be switched on and off by an infinitesimal change in solvent composition. The kinetics of catalysis by the gel in the shrunken state is well described by the Michaelis–Menten formula, indicating that the absorption of the substrate by the hydrophobic environment created by the N-isopropylacrylamide polymer in the shrunken gel is responsible for enhancement of catalytic activity. In the swollen state, the rate vs. active site concentration is linear, indicating that the substrate absorption is not a primary factor determining the kinetics. Catalytic activity of the gel is studied for substrates with various alkyl chain lengths; of those studied the switching effect is most pronounced for p-nitrophenyl caprylate. PMID:10954747

  15. Conducting polymer electrodes for gel electrophoresis.

    Directory of Open Access Journals (Sweden)

    Katarina Bengtsson

    Full Text Available In nearly all cases, electrophoresis in gels is driven via the electrolysis of water at the electrodes, where the process consumes water and produces electrochemical by-products. We have previously demonstrated that π-conjugated polymers such as poly(3,4-ethylenedioxythiophene (PEDOT can be placed between traditional metal electrodes and an electrolyte to mitigate electrolysis in liquid (capillary electroosmosis/electrophoresis systems. In this report, we extend our previous result to gel electrophoresis, and show that electrodes containing PEDOT can be used with a commercial polyacrylamide gel electrophoresis system with minimal impact to the resulting gel image or the ionic transport measured during a separation.

  16. Conducting polymer electrodes for gel electrophoresis.

    Science.gov (United States)

    Bengtsson, Katarina; Nilsson, Sara; Robinson, Nathaniel D

    2014-01-01

    In nearly all cases, electrophoresis in gels is driven via the electrolysis of water at the electrodes, where the process consumes water and produces electrochemical by-products. We have previously demonstrated that π-conjugated polymers such as poly(3,4-ethylenedioxythiophene) (PEDOT) can be placed between traditional metal electrodes and an electrolyte to mitigate electrolysis in liquid (capillary electroosmosis/electrophoresis) systems. In this report, we extend our previous result to gel electrophoresis, and show that electrodes containing PEDOT can be used with a commercial polyacrylamide gel electrophoresis system with minimal impact to the resulting gel image or the ionic transport measured during a separation.

  17. Produção e padronização dos antígenos de Paracoccidioides brasiliensis (Pb, Histoplasma capsulatum (Hc e Aspergillus fumigatus (Af para uso no imunodiagnóstico: comparação entre as técnicas de imunodifusão e imunoeletroosmoforese Production and standardization of Paracoccidioides brasiliensis, Histoplasm capsulatum and Aspergillus fumigatus antigens to be used in immunodiagnosis: comparison between immunodiffusion and immunoelectrophoresis technics

    Directory of Open Access Journals (Sweden)

    Maria de Fátima Ferreira-da-Cruz

    1985-09-01

    Full Text Available Foram produzidos antígenos solúveis de P. brasiliensis, H. capsulatum e A. fumigatus e padronizados nas técnicas de imunodifusão dupla (IDD e imunoeletroosmoforese (IEOF. A especificidade dos antígenos foi testada utilizando-se 96 soros de pacientes com paracoccidioidomicose, histoplasmose, aspergilose, candidíase sistêmica, esporotricose, tuberculose, neoplasia pulmonar, leishmaniose tegumentar e visceral e em 18 indivíduos sadios. Na IDD, a especificidade foi de 100% usando-se como critério de positividade linhas de precipitação com identidade total com soro de referência. Entretanto na IEOF, a especificidade variou de acordo com o antígeno testado, sendo observadas reações cruzadas com antígeno de P. brasiliensis frente a soros de pacientes com histoplasmose (16,7% e leishmaniose tegumentar (10% e com antígeno de H. capsulatum frente a soros de pacientes com paracoccidioidomicose (31,8% e leishmaniose tegumentar (10%. Ambas as técnicas mostraram a mesma sensibilidade para o sorodiagnóstico de paracoccidioidomicose, histoplasmose e aspergilose, respectivamente 100%, 83,3% e 100%. A grande sensibilidade e especificidade da IDD observadas nos soros desses pacientes, aliadas à fácil reprodutibilidade e baixo custo, fazem esta técnica muito apropriada como procedimento de rotina, para a triagem de pacientes sintomáticos respiratórios.Soluble antigens (Ag from Paracoccidioides brasiliensis, Histoplasma capsulatum and Aspergillus fumigatus were prepared and standardized by double immunodiffusion (DID and immunoelectroosmophoresis (IEOP. No difference in sensitivity was observed between the two techniques; 100% of standard patient sera were positive with P. brasiliensis and A. fumigatus Ag and 83.3% were positive with H. capsulatum Ag. The specificity of the tests was verified testing 96 sera from patients with paracoccidioidomycosis, histoplasmosis, systemic candidiasis, sporotrichosis, tuberculosis, lung cancer, visceral or

  18. Organic-inorganic hybrid gels for the selective absorption of oils from water.

    Science.gov (United States)

    Ozan Aydin, Gulsah; Bulbul Sonmez, Hayal

    2016-06-01

    Organic-inorganic hybrid gels were synthesized by the condensation of a linear aliphatic diol (1,8-octanediol) and altering the chain length of the alkyltriethoxysilanes (from ethyltriethoxysilane to hexadecyltrimethoxysilane) through a bulk polymerization process without using any initiator, activator, catalyst, or solvent for the selective removal of oils from water. Fourier transform infrared spectroscopy (FTIR) and solid-state (13)C and (29)Si cross-polarization magic-angle spinning nuclear magnetic resonance (CPMAS NMR) were used for the structural analysis of hybrid gels. Thermal properties of the hybrid gels were determined by thermogravimetric analysis (TGA). Oil absorbency of organic-inorganic hybrid gels was determined by oil absorption tests. The results showed that hybrid gels have high and fast absorption capacities and excellent reusability. Good selectivity, high thermal stability, low density, and excellent recyclability for the oil removal give the material potential applications.

  19. Determination of the gel point of a polyfurfuryl alcohol resin and characterization of its curing rheokinetics

    DEFF Research Database (Denmark)

    Dominguez, Juan Carlos; Madsen, Bo

    2013-01-01

    The determination of the gel point of a resin is a key in order to design and optimize the manufacturing process of composite materials. In this work, the gel point of a biobased polyfurfuryl alcohol (FA) resin has been determined by rheological isothermal tests at different curing temperatures....... The obtained gel times using three different amounts of catalyst (2, 4 and 6 % wt.) were correlated to temperature by the Macosko model; to predict the gel time at any temperature within the studied range. Furthermore, the evolution of the complex viscosity of the FA resin after its gel point has been studied...... of the resin system. The evolution of the viscosity has been modeled using widely used rheokinetic models. Finally, since rheological properties such as viscosity and complex modulus (G*) are highly sensitive to the molecular weight of a polymeric system, and they can be used as indicators of the degree...

  20. A comparative clinical study of Solcoseryl Eye-Gel and Cysteine Eye-Gel 2.4% in the treatment of foreign-body injuries of the cornea.

    Science.gov (United States)

    Studer, O

    1984-01-01

    Solcoseryl, a protein-free haemodialysate, promotes tissue regeneration and improves utilization of oxygen in the cell. In a randomized, double-blind, clinical study, Solcoseryl Eye-Gel was compared with Cysteine Eye-Gel in the treatment of foreign-body injuries of the cornea in a total of 99 eyes. In order to facilitate objective evaluation of the effects of the treatment, the area of the lesion before the start of treatment and on the following day was determined by means of slit-lamp photographs. Healing of the lesion and relative reduction of the area of the wound were observed much more frequently in the group treated with Solcoseryl Eye-Gel than in the reference group. Maculae corneae after the end of the treatment were significantly less frequent under Solcoseryl Eye-Gel than under Cysteine Eye-Gel. Teh tolerability of the test preparation was good; an itching sensation was reported in only 2 cases. Under Cysteine Eye-Gel, on the other hand, a burning sensation was reported by a number of patients and very fine deposits in the epithelium were also observed in a few cases. Thus complete closure of the epithelium over the lesion after 1 day was observed much more frequently in the group of patients treated with Solcoseryl Eye-Gel than in the reference group (63 vs. 53%).

  1. A nonadhesive solid-gel electrode for a non-invasive brain–machine interface

    Directory of Open Access Journals (Sweden)

    Shigeru eToyama

    2012-07-01

    Full Text Available A non-invasive brain–machine interface (BMI or brain-computer interface (BCI is a technology for helping individuals with disabilities and utilizes neurophysiological signals from the brain to control external machines or computers without requiring surgery. However, when applying EEG methodology, users must place EEG electrodes on the scalp each time, and the development of easy-to-use electrodes for clinical use is required. In this study, we developed a conductive nonadhesive solid-gel electrode for practical non-invasive BMIs. We performed basic material testing, including examining the volume resistivity, viscoelasticity, and moisture-retention properties of the solid gel. Then, we compared the performance of the solid gel, a conventional paste, and an in-house metal pin-based electrode using impedance measurements and P300-BMI testing. The solid gel was observed to be conductive (volume resistivity 13.2 Ωcm and soft (complex modulus 105.4 kPa, and it remained wet for a prolonged period (>10 hours in a dry environment. Impedance measurements revealed that the impedance of the solid-gel-based and conventional paste-based electrodes was superior to that of the pin-based electrode. The EEG measurement suggested that the signals obtained with the solid-gel electrode were comparable to those with the conventional paste-based electrode. Moreover, the P300-BMI study suggested that systems using the solid-gel or pin-based electrodes were effective. One of the advantages of the solid gel is that it does not require cleaning after use, whereas the conventional paste adheres to the hair, which requires washing. Furthermore, the solid-gel electrode was not painful compared with a metal-pin electrode. Taken together, the results suggest that the solid-gel electrode worked well for practical BMIs and could be useful for bedridden patients such as those with amyotrophic lateral sclerosis.

  2. Studies of matrix vesicle-induced mineralization in a gelatin gel

    Science.gov (United States)

    Boskey, A. L.; Boyan, B. D.; Doty, S. B.; Feliciano, A.; Greer, K.; Weiland, D.; Swain, L. D.; Schwartz, Z.

    1992-01-01

    Matrix vesicles isolated from fourth-passage cultures of chondrocytes were tested for their ability to induce hydroxyapatite formation in a gelatin gel in order to gain insight into the function of matrix vesicles in in situ mineralization. These matrix vesicles did not appear to be hydroxyapatite nucleators per se since the extent of mineral accumulation in the gel diffusion system was not altered by the presence of matrix vesicles alone, and in the vesicle containing gels, mineral crystals were formed whether associated with vesicles or not. In gels with these matrix vesicles and beta-glycerophosphate, despite the presence of alkaline phosphatase activity, there was no increase in mineral deposition. This suggested that in the gel system these culture-derived vesicles did not increase local phosphate concentrations. However, when known inhibitors of mineral crystal formation and growth (proteoglycan aggregates [4 mg/ml], or ATP [1 mM], or both proteoglycan and ATP) were included in the gel, more mineral was deposited in gels with the vesicles than in comparable gels without vesicles, indicating that enzymes within these vesicles were functioning to remove the inhibition. These data support the suggestion that one function of the extracellular matrix vesicles is to transport enzymes for matrix modification.

  3. New resin gel for uranium determination by diffusive gradient in thin films technique

    International Nuclear Information System (INIS)

    Gregusova, Michaela; Docekal, Bohumil

    2011-01-01

    A new resin gel based on Spheron-Oxin chelating ion-exchanger with anchored 8-hydroxyquinoline functional groups was tested for application in diffusive gradient in thin film technique (DGT) for determination of uranium. Selectivity of uranium uptake from model carbonate loaded solutions of natural water was studied under laboratory conditions and compared with selectivity of the conventional Chelex 100 based resin gel. The affinity of Spheron-Oxin functional groups enables determination of the overall uranium concentration in water containing carbonates up to the concentration level of 10 2 mg L -1 . The effect of uranium binding to the polyacrylamide (APA) and agarose diffusive gels (AGE) was also studied. Uranium is probably bound in both gels by a weak interaction with traces of acrylic acid groups in the structure of APA gel and with pyruvic and sulfonic acid groups in the AGE gel. These sorption effects can be eliminated to the negligible level by prolonged deployment of DGT probes or by disassembling probes after the 1-2 days post-sampling period that is sufficient for release of uranium from diffusive gel and its sorption in resin gel.

  4. Aloe vera phenomenon: a review of the properties and modern uses of the leaf parenchyma gel

    Energy Technology Data Exchange (ETDEWEB)

    Grindlay, D.; Reynolds, T.

    1986-06-01

    The mucilaginous gel from the parenchymatous cells in the leaf pulp of Aloe vera has been used since early times for a host of curative purposes. This gel should be distinguished clearly from the bitter yellow exudate originating from the bundle sheath cells, which is used for its purgative effects. Aloe vera gel has come to play a prominent role as a contemporary folk remedy, and numerous optimistic, and in some cases extravagant, claims have been made for its medicinal properties. Modern clinical use of the gel began in the 1930s, with reports of successful treatment of X-ray and radium burns, which led to further experimental studies using laboratory animals in the following decades. The reports of these experiments and the numerous favourable case histories did not give conclusive evidence, since although positive results were usually described, much of the work suffered from poor experimental design and insufficiently large test samples. In addition some conflicting or inconsistent results were obtained. With the recent resurgence of interest in Aloe vera gel, however, new experimental work has indicated the possibility of distinct physiological effects. Chemical analysis has shown the gel to contain various carbohydrate polymers, notably either glucomannans or pectic acid, along with a range of other organic and inorganic components. Although many physiological properties of the gel have been described, there is no certain correlation between these and the identified gel components. 154 references.

  5. Efficacy of topical azelaic acid gel in the treatment of mild-moderate acne vulgaris

    Directory of Open Access Journals (Sweden)

    Iraji Fariba

    2007-01-01

    Full Text Available Background: Twenty percent azelaic acid gel is recommended as a topical treatment for acne due to its favorable profile. Aim: Our objective in this study was to evaluate the efficacy of 20% azelaic acid gel in the treatment of mild to moderate acne vulgaris. Methods: This was a double blind, randomized clinical trial. Sixty patients with mild to moderate acne vulgaris were selected randomly to receive either azelaic acid gel or the vehicle gel alone. Patients were followed up every 15 days for a period of 45 days. The number of lesions and the acne severity index (ASI were recorded and compared using Student′s t-test. Results: Total lesion count was reduced by 60.6% and 19.9% by azelaic acid gel and the placebo respectively (P =0.002. ASI was reduced by 65.2% and 21.3% by azelaic acid gel and the placebo respectively (P =0.001, i.e., azelaic acid gel was 3.06 times more effective than the placebo in reducing ASI. Conclusion: Azelaic acid gel can be used as an effective treatment in mild to moderate acne vulgaris.

  6. In-vitro activity of sodium-hypochlorite gel on bacteria associated with periodontitis.

    Science.gov (United States)

    Jurczyk, Karolina; Nietzsche, Sandor; Ender, Claudia; Sculean, Anton; Eick, Sigrun

    2016-11-01

    The aim of the present study was to assess the antimicrobial activity of a sodium hypochlorite formulation including its components against bacteria associated with periodontal disease. Sodium hypochlorite formulation (NaOCl gel), its components sodium hypochlorite (NaOCl), and the activating vehicle were compared with 0.1 % chlorhexidine digluconate (CHX) solution. The antimicrobial activity was proven by determination of minimal inhibitory concentrations (MIC), minimal bactericidal concentrations, and killing assays. Furthermore, the influence on formation as well as on a 4-day-old 6-species biofilm was tested. Except for one strain (Parvimonas micra ATCC 33270 in case of NaOCl gel), the MICs both of the CHX solution and NaOCl gel did not exceed 10 % of the formulations' concentration. In general, MICs of the NaOCl gel were equal as of the CHX solution against Gram-negatives but higher against Gram-positive bacteria. CHX but not NaOCl gel clearly inhibited biofilm formation; however, the activity of NaOCl gel was more remarkable on a 4-day-old biofilm. NaOCl killed bacteria in the biofilm and interfered with the matrix. The NaOCl gel acts antimicrobial in particular against Gram-negative species associated with periodontitis. Moreover, its component NaOCl hypochlorite is able to alter biofilm matrices. The NaOCl gel may represent a potential alternative for adjunctive topical antimicrobial treatment in periodontitis.

  7. Processing and stabilization of Aloe Vera leaf gel by adding chemical and natural preservatives

    Directory of Open Access Journals (Sweden)

    N. Nazemi

    2017-11-01

    Full Text Available Background and objectives: Aloe vera has been used as a medicinal herb for thousands of years. Aloe vera leaves can be separated into latex and gel which have biological effects. Aloe gel is a potent source of polysaccharides. When the gel is exposed to air, it quickly decomposes and decays and loses most of its biological activity. There are various processing techniques for sterilizing and stabilizing the gel. The aim of this study was to improve stabilization of the gel by adding some chemical and natural preservatives. Methods: The gel was obtained from Aloe vera leaves and after some processing chemical and natural preservatives were added. Chemicals included citric acid, ascorbic acid, vitamin E and potassium sorbate while natural preservatives were two essential oils derived from Cinnamomum zeylanicum and Eugenia caryophyllata. All these operations were performed under sterile conditions and they were evaluated at different temperatures and times. Appearance and taste changes of gel were studied organoleptic. Microbiological tests and some physical assays such as pH, refractometry and viscosity properties as well as determination of total sugars were measured. NMR and FT-IR analyses were performed for determining the quality of samples. Results: After data analyzing, the results showed that the samples formulated with chemical additives together with essential oils were more suitable and stable compared to the control samples after 90 days and the effective ingredient acemannan, remained stable. Conclusion: The stable gel can be considered for therapeutic properties and be used for edible and medicinal purposes.

  8. Efficacy of topical azelaic acid gel in the treatment of mild-moderate acne vulgaris.

    Science.gov (United States)

    Iraji, Fariba; Sadeghinia, Ali; Shahmoradi, Zabiholahi; Siadat, Amir Hossein; Jooya, Abolfazl

    2007-01-01

    Twenty percent azelaic acid gel is recommended as a topical treatment for acne due to its favorable profile. Our objective in this study was to evaluate the efficacy of 20% azelaic acid gel in the treatment of mild to moderate acne vulgaris. This was a double blind, randomized clinical trial. Sixty patients with mild to moderate acne vulgaris were selected randomly to receive either azelaic acid gel or the vehicle gel alone. Patients were followed up every 15 days for a period of 45 days. The number of lesions and the acne severity index (ASI) were recorded and compared using Student's t-test. Total lesion count was reduced by 60.6% and 19.9% by azelaic acid gel and the placebo respectively (P = 0.002). ASI was reduced by 65.2% and 21.3% by azelaic acid gel and the placebo respectively (P = 0.001), i.e, azelaic acid gel was 3.06 times more effective than the placebo in reducing ASI. Azelaic acid gel can be used as an effective treatment in mild to moderate acne vulgaris.

  9. Anti-inflammatory effect of diclofenac diethylammonium gel on acute phase of ligature induced periodontitis in rats

    OpenAIRE

    Botelho, Marco A.; Paixão, Mônica S.; Rachid, Ítalo; Bannet, Leonard Edward; Patrus, Ana Helena; Mattos, Thiago Borges; Queiroz, Dinalva; Ruela, Ronaldo; Costa, Jose M. C; Quintans Júnior, Lucindo José

    2010-01-01

    This study aimed to evaluate the effect of a diclofenac diethylammonium gel 10 mg/g (DD) on acute phase of ligature induced periodontitis model in rats. Experimental Periodontitis Disease (EPD) was induced in 30 Wistar rats subjected to ligature placement on left molars. Animals were treated with (DD), immediately after (EPD) induction. Saline-based gel (SG) was utilized as negative control and DD gel 10 mg/g was the tested substance. Animals were randomly assigned into the groups. The period...

  10. Preparation of continuous alumina gel fibres by aqueous sol–gel ...

    Indian Academy of Sciences (India)

    sol–gel process using aluminum-tri-isopropoxide as starting materials, and Shojaie-Bahaabad et al (2008) synthesized composite fibres (YAG/Al2O3) from an aqueous solution of aluminum powder, aluminum chloride hexahydrate and yttrium oxide by the sol–gel method. But, the preparation processes of continuous gel ...

  11. New decontamination techniques: chemical gels, electropolishing and abrasives

    International Nuclear Information System (INIS)

    Brunel, G.; Gauchon, J.P.; Kervegant, Y.; Josso, F.

    1991-01-01

    The decommissioning of nuclear installations requires decontamination techniques that are efficient, simple to apply and producing a small amount of wastes, which are easy to process. With a view to this, three decontamination methods, which appear to be particularly suited to decommissioning, have been studied. These three methods are: - spraying of gels carrying chemical decontaminating agents, - electropolishing with a swab device, - abrasives blasting. After parametric tests on non-radioactive and active samples, the industrial application of these methods in the dismantling of installations was studied. These industrial applications concern: - decontamination of pieces coming from the German BWR ISAR by immersion and gel spraying, - decontamination, mainly by gel spraying, and dismantling of the BRENNILIS bituminisation plant, - decontamination of part of the cooling circuit of the graphite gas reactor G2 by gel spraying, - decontamination of a component of the FBR SuperPhenix, using dry abrasives blasting. During the first three applications, generated secondary wastes volume and form were determined. 33 tabs., 16 figs., 12 refs

  12. Tolterodine Tartrate Proniosomal Gel Transdermal Delivery for Overactive Bladder

    Directory of Open Access Journals (Sweden)

    Rajan Rajabalaya

    2016-08-01

    Full Text Available The goal of this study was to formulate and evaluate side effects of transdermal delivery of proniosomal gel compared to oral tolterodine tartrate (TT for the treatment of overactive bladder (OAB. Proniosomal gels are surfactants, lipids and soy lecithin, prepared by coacervation phase separation. Formulations were analyzed for drug entrapment efficiency (EE, vesicle size, surface morphology, attenuated total reflectance Fourier transform infrared (ATR-FTIR spectroscopy, in vitro skin permeation, and in vivo effects. The EE was 44.87%–91.68% and vesicle size was 253–845 nm for Span formulations and morphology showed a loose structure. The stability and skin irritancy test were also carried out for the optimized formulations. Span formulations with cholesterol-containing formulation S1 and glyceryl distearate as well as lecithin containing S3 formulation showed higher cumulative percent of permeation such as 42% and 35%, respectively. In the in vivo salivary secretion model, S1 proniosomal gel had faster recovery, less cholinergic side effect on the salivary gland compared with that of oral TT. Histologically, bladder of rats treated with the proniosomal gel formulation S1 showed morphological improvements greater than those treated with S3. This study demonstrates the potential of proniosomal vesicles for transdermal delivery of TT to treat OAB.

  13. [GPC Fingerprint Chromatograms of Aloe vera Leaf Gel Polysaccharides].

    Science.gov (United States)

    Wang, Qiao-e; Xie, Dan; Qian, Jie; Dong, Yin-mao

    2015-10-01

    To establish the gel permeation chromatography (GPC) fingerprint chromatograms of polysaccharides in Aloe vera leaf gel from the same habitat (Beijing) and different habitats for evaluating the quality of Aloe vera leaf gel products commercially available and testing common adulterated substances. The samples were prepared by water-extraction and alcohol-precipitation method. GPC separation was performed on a Shodex SUGAR KS-805 (300 mm x 8.0 mm, 7 μm) column and a Shodex SUGAR KS-803 (300 mm x 8.0 mm, 6 μm) column at the temperature of 60 degrees C by eluting with 0.1 mol/L NaNO3 (containing 0.2 per thousand NaN) at a flow rate of 0.8 mL/min, the chromatographic effluent was detected by refractive index detector (RID) at the temperature of 50 degrees C. The common pattern of GPC fingerprint chromatograms was established and four common peaks were demarcated. The similarities of samples from the same habitat (Beijing) and different habitats were over 0.9. Taking the GPC fingerprint chromatograms for the qualified model, three commercially available aloe products were evaluated to be made of Aloe vera by the different manufacturing processes and four common adulterated substances of aloe polysaccharides were identified effectively. The method is simple and accurate with a good reproducibility, and it can be used for the identification and quality evaluation of Aloe vera leaf gel products.

  14. Preparative electrophoresis on linear polyacrylamide-agarose composite gels.

    Science.gov (United States)

    Shainoff, J R; Smejkal, G B; Mitkevich, O; DiBello, P M

    1996-01-01

    A preparative method for isolating centigram quantities of high molecular weight polypeptide chains with high resolution and recovery uses linear polyacrylamide/agarose composite (LPAC) gels as electrophoretic media from which the polypeptides can be easily extracted. The composites are prepared in a manner yielding linear copolymers of acrylamide and 1-allyloxy-2,3-propanediol within 2% agarose gels. After electrophoresis in sodium dodecyl sulfate (SDS), protein bands were rapidly visualized for excision by briefly immersing the gel in cold 0.1 M KCl which precipitates the protein-associated SDS. The gel slices are then freeze-thawed to disrupt the agarose matrix and promote syneresis of fluid upon centrifugation. The polypeptides are then separated from the polyacrylamide in the supernatant solution by precipitating with either acidic isopropanol, trichloroacetic acid, ammonium sulfate or other general protein precipitants. As determined with polypeptide chains of fibrinogen and its cross-linked derivatives, recoveries were virtually complete (95.4% +/- 2.2%), and were independent of molecular weights over the range tested (10(4) --10(6)).

  15. Topological characteristics of model gels

    International Nuclear Information System (INIS)

    Miller, Mark A; Hansen, Jean-Pierre; Blaak, Ronald

    2010-01-01

    The Euler characteristic of an object is a topological invariant determined by the number of handles and holes that it contains. Here, we use the Euler characteristic to profile the topology of model three-dimensional gel-forming fluids as a function of increasing length scale. These profiles act as a 'topological fingerprint' of the structure, and can be interpreted in terms of three types of topological events. As model fluids we have considered a system of dipolar dumbbells, and suspensions of adhesive hard spheres with isotropic and patchy interactions in turn. The correlation between the percolation threshold and the length scale on which the Euler characteristic passes through zero is examined and found to be system-dependent. A scheme for the efficient calculation of the Euler characteristic with and without periodic boundary conditions is described.

  16. Chitosan: Gels and Interfacial Properties

    Directory of Open Access Journals (Sweden)

    Julie Nilsen-Nygaard

    2015-03-01

    Full Text Available Chitosan is a unique biopolymer in the respect that it is abundant, cationic, low-toxic, non-immunogenic and biodegradable. The relative occurrence of the two monomeric building units (N-acetyl-glucosamine and d-glucosamine is crucial to whether chitosan is predominantly an ampholyte or predominantly a polyelectrolyte at acidic pH-values. The chemical composition is not only crucial to its surface activity properties, but also to whether and why chitosan can undergo a sol–gel transition. This review gives an overview of chitosan hydrogels and their biomedical applications, e.g., in tissue engineering and drug delivery, as well as the chitosan’s surface activity and its role in emulsion formation, stabilization and destabilization. Previously unpublished original data where chitosan acts as an emulsifier and flocculant are presented and discussed, showing that highly-acetylated chitosans can act both as an emulsifier and as a flocculant.

  17. [Value of positive auto controls in the gel centrifugation method].

    Science.gov (United States)

    Eichler, H; Kretschmer, V

    1994-01-01

    We studied 97 samples of patients being positive in the autocontrol of the indirect antiglobulin test (IAT) in the gel system (DiaMed). In 83.2%, retesting with monospecific anti-IgG serum gave also positive results, due to a specific phenomenon caused, for example, by drug-specific antibodies (AB), warm auto-AB or allo-AB. In contrast, only 52.9% of the samples retested by the standard tube technique with polyspecific antiglobulin serum reacted positive. Only in 6 patients slightly increased cold agglutinins could be detected. None of the investigated patients showed any clinical or laboratory signs of hemolysis except one with pernicious anemia. We conclude that positive results of the autocontrol in the gel IAT should be confirmed by an additional DAT in the tube technique. If this second test shows a negative result, transfusions can take place without any restrictions.

  18. Using Greener Gels to Explore Rheology

    Science.gov (United States)

    Garrett, Brendan; Matharu, Avtar S.; Hurst, Glenn A.

    2017-01-01

    A laboratory experiment was developed to investigate the rheological properties of a green calcium-cross-linked alginate gel as an alternative to the traditional borax-cross-linked poly(vinyl alcohol) gel. As borax is suspected of damaging fertility and the unborn child, a safe, green alternative is necessary. The rheological properties of a…

  19. nanocomposite hydrogels with high gel strength

    Indian Academy of Sciences (India)

    used in many fields such as hygienic products,1 agriculture,2,3 waste water treatment,4,5 drug-delivery systems6– ... commercially synthesized hectorite product was used to prepare NC gels by inverse microemulsion poly- ... 2.4 Gel strength evaluation of the nanocomposite hydrogels. The apparent viscosity was a relative ...

  20. Sodium Dedecyl Suphate Polyacrilamide Gel Electrophosis of ...

    African Journals Online (AJOL)

    Sodium Dedecyl Suphate Polyacrilamide Gel Electrophosis of Campylobacter coli. S.I. Smith, M.M. Ibrahim, V.N. Ezeobi, K.S. Oyedeji, K.A. Akinsinde, A.O Coker. Abstract. Campylobacter coli were characterized using sodium dodecyl sulphate-polyacrilamide gel electrophoresis (SDS-PAGE). The isolates were obtained ...

  1. Serum release boosts sweetness intensity in gels

    NARCIS (Netherlands)

    Sala, G.; Stieger, M.A.; Velde, van de F.

    2010-01-01

    This paper describes the effect of serum release on sweetness intensity in mixed whey protein isolate/gellan gum gels. The impact of gellan gum and sugar concentration on microstructure, permeability, serum release and large deformation properties of the gels was determined. With increasing gellan

  2. Nondenaturing agarose gel electrophoresis of RNA.

    Science.gov (United States)

    Rio, Donald C; Ares, Manuel; Hannon, Gregory J; Nilsen, Timothy W

    2010-06-01

    INTRODUCTION Perhaps the most important and certainly the most often used technique in RNA analysis is gel electrophoresis. Because RNAs are negatively charged, they migrate toward the anode in the presence of electric current. The gel acts as a sieve to selectively impede the migration of the RNA in proportion to its mass, given that its mass is generally proportional to its charge. Because mass is approximately related to chain length, the length of an RNA is more generally determined by its migration. In addition, topology (i.e., circularity) can affect migration, making RNAs appear longer on the gel than they actually are. There are two common types of gel: polyacrylamide and agarose. For most applications involving RNAs of or =600 nucleotides, and are especially useful for analysis of mRNAs (e.g., by Northern blotting). RNA analysis on agarose gels is essentially identical to DNA analysis (except that the gel boxes used must be dedicated to RNA work or to other ribonuclease-free work). Here we describe the use of straightforward Tris borate, EDTA (TBE) gels for routine analysis. These gels are appropriate for determining the quantity and integrity of RNA before using it for other applications. This procedure should not be used to determine size with accuracy, because the RNA will not remain in its extended state throughout the run.

  3. Fast Processing of Sol-Gel TCO

    NARCIS (Netherlands)

    Deelen, J. van; Rem, M.; Arfsten, N.; Buskens, P.P.

    2016-01-01

    TCOs are usually deposited using sputtering or chemical vapor deposition, which have a yield of typically 50-75%. The sol gel method does not need low pressure and can be done with a high precursor yield in the range of 90 – 100%. Sol gel enables also the TCO function as a planarization or

  4. Recrystallization of amylopectin in concentrated starch gels

    NARCIS (Netherlands)

    Keetels, CJAM; Oostergetel, GT; vanVliet, T

    The relation between the recrystallization of amylopectin and the increase in stiffness of starch gels during storage was studied by various techniques. From transmission electron microscopy it was concluded that the size of the crystalline domains in retrograded 30% w/w potato starch gels was about

  5. Silica gel matrix immobilized Chlorophyta hydrodictyon africanum ...

    African Journals Online (AJOL)

    Chlorophyta hydrodictyon africanum was immobilized on a silica gel matrix to improve its mechanical properties. The algae-silica gel adsorbent was used for batch sorption studies of a cationic dye, methylene blue (MB). Optimum adsorption was obtained with a dosage of 0.8 g bio sorbent. Results from sorption studies ...

  6. Polymer architecture of magnetic gels: a review

    Science.gov (United States)

    Weeber, Rudolf; Hermes, Melissa; Schmidt, Annette M.; Holm, Christian

    2018-02-01

    In this review article, we provide an introduction to ferrogels, i.e. polymeric gels with embedded magnetic particles. Due to the interplay between magnetic and elastic properties of these materials, they are promising candidates for engineering and biomedical applications such as actuation and controlled drug release. Particular emphasis will be put on the polymer architecture of magnetic gels since it controls the degrees of freedom of the magnetic particles in the gel, and it is important for the particle-polymer coupling determining the mechanisms available for the gel deformation in magnetic fields. We report on the different polymer architectures that have been realized so far, and provide an overview of synthesis strategies and experimental techniques for the characterization of these materials. We further focus on theoretical and simulational studies carried out on magnetic gels, and highlight their contributions towards understanding the influence of the gels’ polymer architecture.

  7. FTIR thermal analysis on organofunctionalized silica gel

    Directory of Open Access Journals (Sweden)

    Foschiera José L.

    2001-01-01

    Full Text Available Silica gel modified with organic groups is widely used as a stationary phase for liquid chromatography. Grafting synthesis can be used to obtain stable modified silica gel surfaces. In this work, silica gel (10 nm of pore diameter and surface area of 320 m² g-1 was chemically modified with 3-chloropropyltrimethoxysilane or 3-aminopropyltrimethoxysilane and reacted with aniline, p-anisidine, benzylamine and 3-phenylpropylchloride in order to yield aromatic groups immobilized on the silica gel surface. Infrared spectroscopy was utilized for characterization of the aromatic groups grafted on the silica gel surface, using a quartz cell. The solids were heated at several temperatures in high vacuum and the infrared band areas of the organic groups were used to evaluate the thermal stability.

  8. Recent Advances in Supramolecular Gels and Catalysis.

    Science.gov (United States)

    Fang, Weiwei; Zhang, Yang; Wu, Jiajie; Liu, Cong; Zhu, Haibo; Tu, Tao

    2018-04-04

    Over the past two decades, supramolecular gels have attracted significant attention from scientists in diverse research fields and have been extensively developed. This review mainly focuses on the significant achievements in supramolecular gels and catalysis. First, by incorporating diverse catalytic sites and active organic functional groups into gelator molecules, supramolecular gels have been considered as a novel matrix for catalysis. In addition, these rationally designed supramolecular gels also provide a variety of templates to access metal nanocomposites, which may function as catalysts and exhibit high activity in diverse catalytic transformations. Finally, as a new kind of biomaterial, supramolecular gels formed in situ by self-assembly triggered by catalytic transformations are also covered herein. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Fibrinopeptide A radioimmunoassay by the gel adsorption method

    International Nuclear Information System (INIS)

    Borlinghaus, P.

    1981-01-01

    The aim of these studies was to test the fibrinopeptide-A radioinmunoassay by the gel adsorption method for its clinical application, its validity and its accuracy concerning clinical questions. Fibrinopeptide-A levels (individual values) and the kinetics of fibrinopeptide-A liberation in vitro (FPA-formation curves) were therefore determined for 'normal persons' and patients with various illnesses. (orig./MG) [de

  10. Evaluation of tilapia skin gelatin as a mammalian gelatin replacer in acid milk gels and low-fat stirred yogurt.

    Science.gov (United States)

    Pang, Zhihua; Deeth, Hilton; Yang, Hongshun; Prakash, Sangeeta; Bansal, Nidhi

    2017-05-01

    Tilapia skin gelatin (TSG) was studied in a 3-stage process (cooling, annealing, and heating) for pure gelatin gels and in a 4-stage process (acidification, cooling, annealing, and heating) for acid milk gels and cultured yogurt. The aim was to evaluate the use of TSG as a replacement for mammalian gelatin in yogurt. In pure TSG gels, stronger gels with higher melting temperatures were formed with increasing TSG concentrations. Compared with bovine gelatin (BG), which gelled at a concentration of 2.5%, TSG gels had lower gelling (14.1°C) and melting (24°C) temperatures but comparable storage moduli during annealing. In acid milk gels, addition of TSG increased the firmness of the gels with increasing concentration. Gelling and melting points of TSG in milk gels were observed at sufficient concentrations during cooling and heating. Strands and sheets were observed in the electron micrographs of milk gels with 1% TSG and a very dense structure was observed with 2.5% TSG. Yogurt with 0.4% TSG had similar viscosity, consistency, pseudoplasticity, and thixotropy as yogurt containing 0.4% BG; no difference was perceived by sensory panelists according to a triangle test. Addition of 0.4% TSG completely prevented whey separation from the acid milk gel and yogurt. The results suggest that TSG could be a suitable replacement for mammalian gelatin in low-fat stirred yogurt. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  11. Three dimensional gel dosimetry by use of nuclear magnetic resonance imaging (MRI)

    Energy Technology Data Exchange (ETDEWEB)

    De Deene, Y.; De Wagter, C.; Van Duyse, B.; Achten, E.; De Neve, W. [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde; De Poorter, J. [Ghent Univ. (Belgium). Dept. of Magnetic Resonance

    1995-12-01

    As co-monomers are found to polymerize by radiation, they are eligible for constructing a three dimensional dosimeter. Another kind of three dimensional dosimeter, based on the radiation sensitivity of the ferrous ions in a Fricke solution, was tested in a previous study. However, a major problem that occurs in this kind of gel dosimeters is the diffusion of the ferric and ferrous ions. The co-monomer gels are more stable. The degree of polymerisation is visualized with a clinical MRI system. Acrylamide and N,N-methylene-bis-acrylamide are dissolved in a gel composed of gelatin and water. By irradiation the co-monomers are polymerized to polyacrylamide. The gel is casted in humanoid forms. As such, a simulation of the irradiation of the patient can be performed. Magnetic resonance relaxivity images of the irradiated gel display the irradiation dose. The images of the gel are fused with the radiological images of the patient. Quantitation of the dose response of the co-monomer gel is obtained through calibration by test tubes.

  12. Formulation and evaluation of topical herbal gel for the treatment of arthritis in animal model

    Directory of Open Access Journals (Sweden)

    Rajasekaran Aiyalu

    Full Text Available ABSTRACT The objective of the study is to formulate and evaluate a topical herbal gel containing Cardiospermum halicacabum and Vitex negundo leaf extracts for their anti-arthritic activity in rats. Twelve herbal gel formulations were prepared using 1.5% of gelling agents carbopol 934 (F1-F6 and carbopol 940 (F6-F12 and they were evaluated for physical appearance, net content, viscosity, extrudability, pH, spreadability, in vitro diffusion profile and primary skin irritation tests. The stability study for the topical herbal gel formulation was done as per ICH guidelines and anti-arthritic activity was evaluated by Freund's Complete Adjuvant (FCA induced arthritis method. Assessment of body weight, paw volume, hematological and biochemical parameters, histopathological examination and In vitro determination of serum biomarkers were also carried out. Formulated gels were homogenous, stable and complied with the guidelines. Among the formulations, F4 showed better release (98.4 % characteristics than other formulations. No erythema or edema was observed in the skin irritation test confirming the gel was non-toxic and safe. Topical application of the herbal gel F4 containing carbopol 934 displayed significant (p < 0.001 anti-arthritic activity compared to diseased rats. Reduction in paw volume, no agglutination in C - reactive protein and rheumatic factor, reduction in TNF level, regaining of normal hematological, and biochemical parameters, reduction in spleen and thymus weight and histopathological examination supported the anti-arthritic activity of the gel formulation.

  13. Effect of nightguard vital bleaching gel on the color stability of provisional restorative materials.

    Science.gov (United States)

    Bajunaid, Salwa Omar

    2016-01-01

    To assess the hypothesis that there was no difference in effect of 10% and 15% tooth bleaching agents on color stability of materials used for provisional fixed dental prosthesis. Fifteen samples from two materials used for provisional fixed dental prosthesis: methacrylate-based and composite-based materials and 15 preformed polycarbonate crowns soaked in bleaching gel or distilled water. Spectrophotometer recorded color of specimens at baseline, after 3, 7, and 14 days. Data were statistically analyzed using two-factor ANOVA test to compare the color stability of tested materials. Methyl-based provisional material exhibited statistically higher color change when exposed to 10% and 15% bleaching gel (delta EFNx01: 9.0 and 11.1, respectively) as compared to distilled water (delta EFNx01: 2.9). Delta EFNx01 of composite-based material specimens exposed to distilled water was statistically higher (6.3) than specimens exposed to 10% and 15% bleaching gel (1.5 and 1.1, respectively). Polycarbonate crowns showed a statistically lower color change when exposed to 15% (0.9) than to 10% bleaching gel (5.1) or distilled water (5.5). Composite-based provisional material showed highest color stability when exposed to vital tooth bleaching gel, whereas methacrylate-based material was the least color stable. Polycarbonate crowns were more color stable when exposed to 15% bleaching gel as opposed to 10% bleaching gel.

  14. Gelatin increases the coarseness of whey protein gels and impairs water exudation from the mixed gel at low temperatures

    NARCIS (Netherlands)

    Martin, A.H.; Bakhuizen, E.; Ersch, C.; Urbonaite, V.; Jongh, H.H.J. de; Pouvreau, L.

    2016-01-01

    To understand the origin of water holding of mixed protein gels, a study was performed on water exudation from mixed whey protein (WP)-gelatin gels upon applied pressure. Mixed gels were prepared with varying WP and gelatin concentration and gelatin type to obtain gels with a wide range of gel

  15. Internal structure analysis of particle-double network gels used in a gel organ replica

    Science.gov (United States)

    Abe, Mei; Arai, Masanori; Saito, Azusa; Sakai, Kazuyuki; Kawakami, Masaru; Furukawa, Hidemitsu

    2016-04-01

    In recent years, the fabrication of patient organ replicas using 3D printers has been attracting a great deal of attention in medical fields. However, the cost of these organ replicas is very high as it is necessary to employ very expensive 3D printers and printing materials. Here we present a new gel organ replica, of human kidney, fabricated with a conventional molding technique, using a particle-double network hydrogel (P-DN gel). The replica is transparent and has the feel of a real kidney. It is expected that gel organ replicas produced this way will be a useful tool for the education of trainee surgeons and clinical ultrasonography technologists. In addition to developing a gel organ replica, the internal structure of the P-DN gel used is also discussed. Because the P-DN gel has a complex structure comprised of two different types of network, it has not been possible to investigate them internally in detail. Gels have an inhomogeneous network structure. If it is able to get a more uniform structure, it is considered that this would lead to higher strength in the gel. In the present study we investigate the structure of P-DN gel, using the gel organ replica. We investigated the internal structure of P-DN gel using Scanning Microscopic Light Scattering (SMILS), a non-contacting and non-destructive.

  16. Platelets stimulate fibroblast-mediated contraction of collagen gels

    Directory of Open Access Journals (Sweden)

    Lundahl Joachim

    2003-10-01

    Full Text Available Abstract Background Platelets are thought to play a role in a variety of inflammatory conditions in the lung, some of which may lead to fibrosis. In the current study we tested the hypothesis that whole platelets and platelet lysate can mediate remodelling of extracellular matrix in vitro by affecting fibroblast-mediated contraction of a collagen gel. We also sought to determine to what extent platelet-derived growth factor (PDGF and transforming growth factor-β (TGF-β contribute to this effect. Methods Washed platelets, isolated from healthy blood donors, and platelet lysate (freezing and thawing, were cast together with human lung fibroblasts in three-dimensional collagen gels. The gels were then released and cultured for four days. PDGF and TGF-β1 concentrations were measured in culture supernatants by ELISA. Results Both platelets and platelet lysate augmented fibroblast-mediated gel contraction in a time and concentration dependent manner (19.9% ± 0.1 (mean ± SEM of initial area vs. 48.0% ± 0.4 at 48 hours; P 1 and PDGF-AA/AB were released in co-culture. PDGF-AA/AB had a maximum release at 24 hours whereas TGF-β1 release increased with longer culture periods. Neutralising antibodies to these mediators partially inhibited platelet-induced gel contraction. Conclusion We conclude that platelets may promote remodelling of extracellular matrix in vitro and that PDGF and TGF-β partially mediate this effect, also indicating a role for other mediators. The findings may be an important mechanism in regulating repair processes after injury.

  17. Effect of natural gel product on bovine dentin erosion in vitro

    Directory of Open Access Journals (Sweden)

    Andre de Carvalho SALES-PERES

    2013-12-01

    Full Text Available Objective: To evaluate the efficacy of Neem (Azadirachta indica experimental gel for the prevention of erosive wear on bovine dentin, in vitro. Material and Methods: One hundred dentin blocks were allocated into 5 experimental groups (20 samples each: C (control group, without gel; CG (control group, only base gel; F (fluoride gel, 1.23% NaF; pH 4.1, Dentsply; Brazil; N (Neem gel, 10% neem extract; pH 4.1, manipulation; NF (Neem+fluoride gel, 10% Neem extract and 1.23% NaF; pH 4.1, manipulation. The blocks were stored in artificial saliva for 24 hours. After this, they were submitted to six alternating re- and demineralization cycles. The blocks were analyzed for wear (profilometry. The results were submitted to statistical analysis by ANOVA and Tukey tests (P<0.05. Results: The mean wear (±SD, µm was shown as follows in groups: C (13.09±0.99, CG (10.60±1.99, F (10.90±1.44, N (12.68±1.13 and NF (10.84±1.65. All gels showed some preventive action when compared with control group. However, significant differences were found only between Neem+fluoride gel and fluoride gel. Conclusion: A single application of a neem-containing fluoride gel reduced dentin erosion, thus it is a possible alternative in reducing dental wear. Further research should investigate the action mechanism and the synergism between them.

  18. Effect of a 0.5% chlorhexidine gel on dental plaque superinfecting microorganisms in mentally handicapped patients.

    Science.gov (United States)

    Pannuti, Cláudio Mendes; Lotufo, Roberto Fraga Moreira; Cai, Silvana; Saraiva Md, Maria da Conceição; de Freitas, Nívea Maria; Falsi, Danilo

    2003-01-01

    A randomized clinical trial was conducted to investigate the effect of a 0.5% chlorhexidine (CHX) gel on dental plaque superinfecting microorganisms in mentally handicapped patients. Thirty inmates from the institution "Casas André Luiz" were assigned to either test group (CHX gel, n = 15) or control group (placebo gel, n = 15). The gel was administered over a period of 8 weeks. Supragingival plaque samples were collected at baseline, after gel use (8 weeks) and 16 weeks after baseline. The presence of Gram-negative Enterobacteriaceae, Staphylococcus and yeasts was evaluated. No significant growth of any superinfecting microorganism was observed in the CHX group, when compared to the placebo group. The results indicated that the 0.5% chlorhexidine gel did not produce an undesirable shift in these bacterial populations.

  19. Effect of a 0.5% chlorhexidine gel on dental plaque superinfecting microorganisms in mentally handicapped patients Efeito do gel de clorexidina a 0,5% em microrganismos superinfectantes da placa bacteriana de portadores de necessidades especiais

    Directory of Open Access Journals (Sweden)

    Cláudio Mendes Pannuti

    2003-09-01

    Full Text Available A randomized clinical trial was conducted to investigate the effect of a 0.5% chlorhexidine (CHX gel on dental plaque superinfecting microorganisms in mentally handicapped patients. Thirty inmates from the institution "Casas André Luiz" were assigned to either test group (CHX gel, n = 15 or control group (placebo gel, n = 15. The gel was administered over a period of 8 weeks. Supragingival plaque samples were collected at baseline, after gel use (8 weeks and 16 weeks after baseline. The presence of Gram-negative Enterobacteriaceae, Staphylococcus and yeasts was evaluated. No significant growth of any superinfecting microorganism was observed in the CHX group, when compared to the placebo group. The results indicated that the 0.5% chlorhexidine gel did not produce an undesirable shift in these bacterial populations.Foi conduzido um ensaio clínico aleatório com objetivo de investigar o efeito do gel de clorexidina (CHX a 0,5% sobre microorganismos superinfectantes da placa bacteriana de pacientes especiais. Trinta internos da instituição "Casas André Luiz" foram aleatoriamente divididos em grupo teste (gel de CHX, n = 15 e controle (gel placebo, n = 15. O gel foi utilizado por oito semanas. Amostras de placa supragengival foram coletadas no início do estudo, após o uso do gel (oito semanas e 16 semanas após o início do estudo. Foi avaliada a presença de bacilos entéricos Gram-negativos, Staphylococcus e leveduras. Não houve diferença entre os grupos quanto à presença desses microorganismos em qualquer momento do estudo. Os resultados indicam que o gel de CHX não provocou mudanças significativas na composição desses microorganismos.

  20. COMPARATIVE ANALYSIS OF BLOOD GROUPING IN HEALTHY BLOOD DONOR USING GEL CARD TECHNIQUE AND TUBE METHOD

    Directory of Open Access Journals (Sweden)

    Muhammad Usman

    2016-12-01

    Full Text Available Blood grouping is a vital test in pre-transfusion testing. Both tube and gel agglutination assays are used for ABO grouping. The main object of this study was to compare ABO grouping and D typing on tube and gel agglutination assay in order to assess the efficacy of each technique. A total of 100 healthy blood donors irrespective of age and sex were included in this study. Results showed that there is no significant difference between these two techniques. However, in 10 samples it was detected that the reaction strength in serum ABO grouping by gel agglutination assay is varied by only one grade when compared to tube agglutination assay. Due to numerous positive effects of gel assay it is more beneficial to implement this technique in the setups where blood banks bear heavy routine work load.

  1. Calcium Impact on Milk Gels Formation

    DEFF Research Database (Denmark)

    Koutina, Glykeria

    enriched dairy products. Calcium gels can be produced by addition of a calcium salt and heat treatment at temperatures higher than 70 oC for several minutes. The combination of heat treatment and calcium addition to milk with pH values between 6.6 and 5.6, will produce calcium milk gels with unique...... and dense gel structure and with little seperation of whey due to participation of calcium to the final gel structure. On the other hand, the combination of heat treatment and calcium addition to milk with pH values lower than 5.6 will still produce gel structures which are dominated by the decrease of p...... to be formed. In addition the low amount of micellar calcium caused a more compact gel structure with many protein aggregates. The results of this study highlighted the importance of calcium for the formation of acid, calcium and rennet gels. The content and the interactions of calcium with proteins during...

  2. Osteoconductive and degradable electrospun nonwoven poly(epsilon-caprolactone)/CaO-SiO2 gel composite fabric.

    Science.gov (United States)

    Seol, Yang-Jo; Kim, Kyoung-Hwa; Kim, In Ae; Rhee, Sang-Hoon

    2010-08-01

    A nonwoven ceramic/polymer composite fabric composed of randomly mixed bioactive and fast degradable CaO-SiO(2) gel fibers and biodegradable poly(epsilon-caprolactone) (PCL) fibers is prepared with a simultaneous electrospinning method for potential use as bone grafting materials. A 17% PCL solution is prepared using 1,1,3,3-hexafluoro-2-propanol as the solvent, whereas the CaO-SiO(2) gel solution is prepared via a condensation reaction following the hydrolysis of tetraethyl orthosilicate. PCL and CaO-SiO(2) gel solutions are spun simultaneously with two separate nozzles. As controls, pure PCL and CaO-SiO(2) gel nonwoven fabrics are also made by the same methods. The three nonwoven fabrics were exposed to simulated body fluid for 1 week and resulted in the deposition of a layer of apatite crystals on the surfaces of both the CaO-SiO(2) gel and PCL/CaO-SiO(2) gel composite fabrics, but not on the PCL fabric. A tensile strength test showed that the fracture behavior of the CaO-SiO(2) gel fabric was brittle, that of the PCL fabric was ductile-tough, and that of the PCL/CaO-SiO(2) gel composite fabric was intermediate between that of the CaO-SiO(2) gel and PCL fabrics. Our in vivo tests showed that the CaO-SiO(2) gel and PCL/CaO-SiO(2) gel composite fabrics had good osteoconductivity and fast degradation rates in calvarial defects of New Zealand white rabbits within 4 weeks, in contrast to the pure PCL fabric. Together, these results suggest that the composite fabric composed of PCL and CaO-SiO(2) gel fibers must have a great potential for use in applications such as bone grafting because of its good osteoconductivity and adequate mechanical properties. (c) 2010 Wiley Periodicals, Inc.

  3. 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

  4. Application of melanin-free ink as a new antioxidative gel enhancer in sardine surimi gel.

    Science.gov (United States)

    Vate, Naveen Kumar; Benjakul, Soottawat; Agustini, Tri Winarni

    2015-08-30

    The squid ink that is discarded as waste during processing can be effectively utilised as a gel enhancer in surimi gels, especially those prepared from dark-fleshed fish which have poor gel properties. It also acts as an antioxidant, inhibiting lipid oxidation. This investigation aimed to study the effect of melanin-free ink (MFI) from splendid squid (Loligo formosana) on properties and oxidative stability of surimi gel from sardine (Sardinella albella). MFI (0-0.1 g kg(-1) surimi) increased the breaking force and deformation of sardine surimi gel in a dose-dependent manner (P 0.05). The expressible moisture content of gels decreased as the levels of MFI increased (P < 0.05). Based on a microstructure study, gel added with MFI at a level of 0.08 g kg(-1) surimi was denser and finer than that of the control (without MFI). Surimi gels with MFI had lower peroxide values, thiobarbituric acid reactive substances, nonanal and 2-decenal. MFI could improve the properties of sardine surimi gel. Additionally, it was able to prevent lipid oxidation in surimi gels during refrigerated storage. © 2014 Society of Chemical Industry.

  5. Adhesive and structural properties of thermoreversible polyacrylate gels

    Science.gov (United States)

    Flanigan, Cynthia Mowery

    Methods for quantifying very weak adhesive interactions between two bodies in contact have been developed using a low-modulus material in conjunction with a linear elastic fracture mechanics analysis based on the treatment of Johnson, Kendall and Roberts (JKR). Using this approach, axisymmetric adhesion tests have been performed on polyacrylate gel lenses and thin layers, in contact with well-characterized surfaces. These thermally reversible gels were formed by diluting a triblock copolymer with poly(methyl methacrylate) (PMMA) endblocks and a poly(n-butyl acrylate) midblock with a selective solvent for the center block. Rheological studies on this swollen copolymer indicate that the material is completely elastic at room temperature and undergoes a rapid, thermally reversible gelation, thus making it an excellent model system to probe the adhesive properties of soft materials. Adhesive and frictional properties of thin, elastic layers in contact with a glass, hemispherical indenter have been investigated. Studies on these highly compliant gels highlight the significance of finite size corrections to the compliance and displacement between the two contacting bodies. For situations where the applied load is too low to measure experimentally, expressions for G /E, the energy release rate normalized by Young's modulus, are shown to provide an accurate means to quantify adhesion with these low-moduli materials. Small angle X-ray scattering experiments in conjunction with rheological tests have shown that changes in composition and temperature affect the elastic nature of the gel. In addition, an equilibrium gelation process is utilized to produce "dried" polymer layers with reproducible adhesive properties. With this method, acrylic acid moieties have been shown to enhance the adhesive performance of these materials without influencing their structure. Lastly, the development of elastic instabilities within confined gel layers has been examined. The aspect ratio of

  6. Exopolysaccharide influence on acid gel formation

    Directory of Open Access Journals (Sweden)

    K. Yoanidu

    2017-06-01

    Full Text Available Abstract. Turbidimetric monitoring of milk coagulation was conducted in situ. Milk gel was produced by acidification with the use of three strains of starter culture. These strains were characterized by various acidification rate and exopolysaccharides (EPS production. The concentrations of EPS affect mostly the pH of gel formation (5.53 - low EPS – producing strain; 5.33 - medium EPS – producing strain; 5.46 - high EPS – producing strain whereas the time of gel formation depends on the various rate of acidification of all three strains.

  7. Breeder fuel pellet fabrication from gel-sphere conversion

    International Nuclear Information System (INIS)

    McLemore, D.R.; Bennett, D.W.; Hart, P.E.; Norman, R.E.

    1980-01-01

    The development of automated nuclear fuel fabrication methods is the goal of the United States breeder reactor program and will form the technological basis for the future breeder reactor fuel supply. A major factor in achieving this goal is the development of remotely operated fuel fabrication equipment. The program schedule is to demonstrate the feasibility of automated pellet fuel fabrication and remote maintenance techniques by the mid-1980's. Development of major ceramic unit operations and the required computer control system is currently in the engineering testing stage. This report describes the planned program activities for evaluating the gel-sphere conversion process and demonstrating the fabrication of breeder fuel pellets from these gel-derived spheres

  8. Buckling of paramagnetic chains in soft gels.

    Science.gov (United States)

    Huang, Shilin; Pessot, Giorgio; Cremer, Peet; Weeber, Rudolf; Holm, Christian; Nowak, Johannes; Odenbach, Stefan; Menzel, Andreas M; Auernhammer, Günter K

    2016-01-07

    We study the magneto-elastic coupling behavior of paramagnetic chains in soft polymer gels exposed to external magnetic fields. To this end, a laser scanning confocal microscope is used to observe the morphology of the paramagnetic chains together with the deformation field of the surrounding gel network. The paramagnetic chains in soft polymer gels show rich morphological shape changes under oblique magnetic fields, in particular a pronounced buckling deformation. The details of the resulting morphological shapes depend on the length of the chain, the strength of the external magnetic field, and the modulus of the gel. Based on the observation that the magnetic chains are strongly coupled to the surrounding polymer network, a simplified model is developed to describe their buckling behavior. A coarse-grained molecular dynamics simulation model featuring an increased matrix stiffness on the surfaces of the particles leads to morphologies in agreement with the experimentally observed buckling effects.

  9. Evaluation of wheat by polyacrylamide gel electrophoresis

    African Journals Online (AJOL)

    PRECIOUS

    2010-01-11

    04, Inqulab-91 and Rawal-. 87 were evaluated for analysis of variability in seed storage proteins by using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Electrophorogram for each variety were scored ...

  10. Sodium Dedecyl Suphate Polyacrilamide Gel Electrophosis of ...

    African Journals Online (AJOL)

    polyacrilamide gel electrophoresis (SDS-PAGE). The isolates were obtained from the faeces of diarrhoeic children with the age range of 0 t 36 months attending paediatric clinic at the Lagos University Teaching Hospital (LUTH) and Obafemi Awolowo ...

  11. Preparation of zirconium molybdate gel generator

    International Nuclear Information System (INIS)

    Charoen, S.; Aungurarat, G.; Laohawilai, S.; Sukontpradit, W.; Jingjit, S.

    1994-01-01

    A procedure for preparation of 99mTc generator based on conversion to zirconium molybdate gel of 99Mo produced by neutron activation was reported. The gel was prepared from zirconium oxychloride solution pH 1.6, ammonium molybdate solution pH 3-5 and mole ratio of Zr:Mo 1:1 which had water content about 7-8%. Small generators containing 1-1.5 g of gel were eluted with average efficiencies of 77% and the activity peak in the first 3 ml of 10 ml of saline solution. The amount of Mo and Zr in eluates were below the acceptance limit. The gel generators of activity about 100 mCi were prepared and had the good performance in elutability and stability

  12. Thixotropic corrosive gels for nuclear decontamination

    International Nuclear Information System (INIS)

    Bargues, St.

    1998-01-01

    The aim of this thesis was the development of corrosive gels for metallic surface decontamination. These gels formulation, based on a powerful oxidant (the cerium IV), the nitric acid, a mineral charge (silica) and a non ionic surface-active, has been developed according to the specific constraints of the nuclear industry. The objective was to prepare thixotropic gels becoming liquid after shacking to allow an easy pulverization and coming again solid to permit a perfect adhesion on the metallic surface. This rheological study of the gels has been completed by an evaluation of their corrosive properties. The last part of the work presents an industrial utilization during two years. (A.L.B.)

  13. Preparasi Katalis Cu/Silika Gel dari Kristobalit Alam Sabang serta Uji Aktivitasnya pada Reaksi Dehidrogenasi Etanol

    Directory of Open Access Journals (Sweden)

    Surya Lubis

    2009-06-01

    Full Text Available Cu/Silica gel catalyst preparation by using silica content which is obtained from Sabang natural crystobalit has been done. Isolated silica from crystobalit is reacted with natrium hidroxide to produce silicate natrium that reacted further with sulphate acid to produce silica gel. Silica gel is characterized by infra red spektroscopy dan BET test. BET test result showed that silica gel obtained has specific surface area 260,04 m2/gram and ion Cu  impregnation into silica gel pores produce Cu/silica gel catalyst with spesific surace area 158,53 m/gram ith Cu2+ metal content = 193 ppm. Catalyst activation test Cu/silica gel at dehidrogenation reaction of etanol to produce asetaldehide was done at temperature 100oC – 300oC. Reseach showed that the highest asetaldehide consentration (20,24% is obtained at temperature 300oC.   Keywords: asetaldehide, crystobalit, Cu/silica gel, dehidrogenation, ethanol

  14. Detection of pectinesterase in polyacrylamide gels.

    Science.gov (United States)

    Alonso, J; Rodríguez, M T; Canet, W

    1995-01-01

    A rapid and sensitive method of detecting pectinesterase activity following electrophoresis or isoelectric focusing in polyacrylamide gels is described. The method uses ruthenium red and requires no addition of substrate when making the gels, thus obviating direct enzyme-substrate contact during electrophoresis. Because of its versatility, the method can be used in a wide variety of applications, such as plant and microbial taxonomy, enzyme purification and characterization, or as an analytical method in fresh and processed plant technology.

  15. Conducting Polymer Electrodes for Gel Electrophoresis

    OpenAIRE

    Bengtsson, Katarina; Nilsson, Sara; Robinson, Nathaniel D

    2014-01-01

    In nearly all cases, electrophoresis in gels is driven via the electrolysis of water at the electrodes, where the process consumes water and produces electrochemical by-products. We have previously demonstrated that p-conjugated polymers such as poly(3,4-ethylenedioxythiophene) (PEDOT) can be placed between traditional metal electrodes and an electrolyte to mitigate electrolysis in liquid (capillary electroosmosis/electrophoresis) systems. In this report, we extend our previous result to gel ...

  16. Sol-Gel Synthesis, Electrochemical Characterization, and Stability Testing of Ti0.7W0.3O2 Nanoparticles for Catalyst Support Applications in Proton-Exchange Membrane Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Subban, Chinmayee V. [Cornell Univ., Ithaca, NY (United States); Zhou, Qin [Cornell Univ., Ithaca, NY (United States); Hu, Anthony [Cornell Univ., Ithaca, NY (United States); Moylan, Thomas E. [General Motors Research and Development, Warren, MI (United States); Wagner, Frederick T. [General Motors Research and Development, Warren, MI (United States); DiSalvo, Francis J. [Cornell Univ., Ithaca, NY (United States)

    2010-11-19

    The materials currently used in proton-exchange membrane fuel cells (PEMFCs) require complex control of operating conditions to make them sufficiently durable to permit commercial deployment. One of the major materials challenges to allow simplification of fuel cell operating strategies is the discovery of catalyst supports that are much more stable to oxidative decomposition than currently used carbon blacks. Here we report the synthesis and characterization of Ti0.7W0.3O2 nanoparticles (approximately 50 nm diameter), a promising doped metal oxide that is a candidate for such a durable catalyst support. The synthesized nanoparticles were platinized, characterized by electrochemical testing, and evaluated for stability under PEMFC and other oxidizing acidic conditions. Ti0.7W0.3O2 nanoparticles show no evidence of decomposition when heated in a Nafion solution for 3 weeks at 80 °C. In contrast, when heated in sulfuric, nitric, perchloric, or hydrochloric acid, the oxide reacts to form salts such as titanylsulfatehydrate from sulfuric acid. Electrochemical tests show that rates of hydrogen oxidation and oxygen reduction by platinum nanoparticles supported on Ti0.7W0.3O2 are comparable to those of commercial Pt on carbon black.

  17. Squeezing flows of vaginal gel formulations relevant to microbicide drug delivery.

    Science.gov (United States)

    Kieweg, Sarah L; Katz, David F

    2006-08-01

    Efficacy of topical microbicidal drug delivery formulations against HIV depends in part on their ability to coat, distribute, and be retained on epithelium. Once applied to the vagina, a formulation is distributed by physical forces including: gravity, surface tension, shearing, and normal forces from surrounding tissues, i.e., squeezing forces. The present study focused on vaginal microbicide distribution due to squeezing forces. Mathematical simulations of squeezing flows were compared with squeezing experiments, using model vaginal gel formulations. Our objectives were: (1) to determine if mathematical simulations can accurately describe squeezing flows of vaginal gel formulations; (2) to find the best model and optimized parameter sets to describe these gels; and (3) to examine vaginal coating due to squeezing using the best models and summary parameters for each gel. Squeezing flow experiments revealed large differences in spreadability between formulations, suggesting different coating distributions in vivo. We determined the best squeezing flow models and summary parameters for six test gels of two compositions, cellulose and polyacrylic acid (PAA). We found that for some gels it was preferable to deduce model input parameters directly from squeezing flow experiments. For the cellulose gels, slip conditions in squeezing flow experiments needed to be evaluated. For PAA gels, we found that in the absence of squeezing experiments, rotational viscometry measurements (to determine Herschel-Bulkley parameters) led to reasonably accurate predictions of squeezing flows. Results indicated that yield stresses may be a strong determinant of squeezing flow mechanics. This study serves as a template for further investigations of other gels and determination of which sources of rheological data best characterize potential microbicidal formulations. These mathematical simulations can serve as useful tools for exploring drug delivery parameters, and optimizing formulations

  18. Two kinds of ketoprofen enteric gel beads (CA and CS-SA using biopolymer alginate

    Directory of Open Access Journals (Sweden)

    Bingchao Cheng

    2018-03-01

    Full Text Available To obtain expected rapid-release and sustained-release of ketoprofen gel beads, this paper adopted biopolymer alginate to prepare alginate beads and chitosan-alginate gel beads. Formulation factors were investigated and optimized by the single factor test. The release of ketoprofen from calcium alginate gel beads in pH 1.0 hydrochloric acid solution was less than 10% during 2 h, then in pH6.8 was about 95% during 45 min, which met the requirements of rapid-release preparations. However, the drug release of chitosan-alginate gel beads in pH1.0 was less than 5% during 2 h, then in pH6.8 was about 50% during 6 h and reached more than 95% during 12 h, which had a good sustained-release behavior. In addition, the release kinetics of keteprofen from the calcium alginate gel beads fitted well with the Korsmeyer–Peppas model and followed a case-II transport mechanism. However, the release of keteprofen from the chitosan-alginate gel beads exhibited a non-Fickian mechanism and based on the mixed mechanisms of diffusion and polymer relaxation from chitosan-alginate beads. In a word, alginate gel beads of ketoprofen were instant analgesic, while chitosan-alginate gel beads could control the release of ketoprofen during gastro-intestinal tract and prolong the drug's action time. Keywords: Gel beads, Enteric rapid-release, Enteric sustained-release, Ketoprofen

  19. Gel/Space Ratio Evolution in Ternary Composite System Consisting of Portland Cement, Silica Fume, and Fly Ash.

    Science.gov (United States)

    Wu, Mengxue; Li, Chen; Yao, Wu

    2017-01-11

    In cement-based pastes, the relationship between the complex phase assemblage and mechanical properties is usually described by the "gel/space ratio" descriptor. The gel/space ratio is defined as the volume ratio of the gel to the available space in the composite system, and it has been widely studied in the cement unary system. This work determines the gel/space ratio in the cement-silica fume-fly ash ternary system (C-SF-FA system) by measuring the reaction degrees of the cement, SF, and FA. The effects that the supplementary cementitious material (SCM) replacements exert on the evolution of the gel/space ratio are discussed both theoretically and practically. The relationship between the gel/space ratio and compressive strength is then explored, and the relationship disparities for different mix proportions are analyzed in detail. The results demonstrate that the SCM replacements promote the gel/space ratio evolution only when the SCM reaction degree is higher than a certain value, which is calculated and defined as the critical reaction degree (CRD). The effects of the SCM replacements can be predicted based on the CRD, and the theological predictions agree with the test results quite well. At low gel/space ratios, disparities in the relationship between the gel/space ratio and the compressive strength are caused by porosity, which has also been studied in cement unary systems. The ratio of cement-produced gel to SCM-produced gel ( G C to G S C M ratio) is introduced for use in analyzing high gel/space ratios, in which it plays a major role in creating relationship disparities.

  20. Study of nuclear glasses alteration gel and synthesis of some model gels; Etude du gel d`alteration des verres nucleaires et synthese de gels modeles

    Energy Technology Data Exchange (ETDEWEB)

    Ricol, S.

    1995-10-05

    This work deals with the general problem of alteration of the reference nuclear glass R7T7. Attention is paid particularly to the altered layer formed at the glass surface during alteration process. In opposition to previous works, related essentially to glass dissolution kinetics based on chemical analyses of lixiviated elements, this thesis deals with alteration problems through structural studies of the reference glass and derived gel. This approach allows the determination of mechanisms for the gel formation and a better understanding of the behaviour of glasses towards lixiviation. Both approaches appeared complementary. Based on several spectroscopic techniques, this work showed the particular role of cations such as calcium, zirconium and iron. Studies of silica-based synthetic gels showed the synergic effect of formers cation and of one highly coordinated cation. The variation of the wavenumber related to Si-O-Si asymmetric stretching vibration can be correlated to O/Si ratio for ternary systems Si/Na/Zr. On the contrary, the Si losses of the materials depend on the number of non-bridging oxygen atoms. In the perspective of long-term behaviour, the alteration gel presents better characteristics than initial glass. It is therefore a highly stable material in static conditions. In the same way, synthetic gels are materials with very low solubilities (much lower than the alteration gel) and could be used as confining matrices. (authors). refs., 71 figs., 37 tabs.

  1. Polymeric gels for intravaginal drug delivery.

    Science.gov (United States)

    Cook, Michael T; Brown, Marc B

    2018-01-28

    Intravaginal drug delivery can elicit a local effect, or deliver drugs systemically without hepatic first pass metabolism. There are a number of emerging areas in intravaginal drug delivery, but the vagina is a challenging route of administration, due to the clearance mechanisms present which result in poor retention of dosage forms, and the potential for irritation and other adverse reactions. Gel formulations are desirable due to the ease of application, spreading and that they cause little to no discomfort to the patient. However, these dosage forms, in particular, are poorly retained and traditional gels typically have little control over drug release rates. This has led to a large number of studies on improving the retention of vaginal gels and modulating the controlled release of drugs from the gel matrix. This review outlines the anatomy and physiology of the vagina, focussing on areas relevant to drug delivery. Medical applications of vaginally administered medicines is then discussed, followed by an overview of polymeric gels in intravaginal drug delivery. The sensorial properties of intravaginal gels, and how these relate to user compliance are also summarised. Finally, some important barriers to marketing approval are described. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Basic investigations on LCV micelle gel

    Science.gov (United States)

    Ebenezer, S. B.; Rafic, M. K.; Ravindran, P. B.

    2013-06-01

    The aim of this study was to investigate the feasibility of using Leuco Crystal Violet (LCV) based micelle gel dosimeter as a quality assurance tool in radiotherapy applications. Basic properties such as absorption coefficient and diffusion of LCV gel phantom over time were evaluated. The gel formulation consisted of 25 mM Trichloroacetic acid, 1mM LCV, 4 mM Triton X-100, 4% gelatin by mass and distilled water. The advantages of using this gel are its tissue equivalence, easy and less preparation time, lower diffusion rate and it can be read with an optical scanner. We were able to reproduce some of the results of Babic et al. The peak absorption was found to be at 600 nm and hence a matrix of yellow LEDs was used as light source. The profiles obtained from projection images confirmed the diffusion of LCV gel after 6 hours of irradiation. Hence the LCV gel phantom should be read before 6 hours post irradiation to get accurate dose information as suggested previously.

  3. Gel nano-particulates against radioactivity; Des nanoparticules en gel contre la radioactivite

    Energy Technology Data Exchange (ETDEWEB)

    Deroin, Ph

    2004-11-01

    The Argonne research center (USA) has developed a 'super-gel' compound, a polymer close to those used in baby's diapers, which can reach a 90% efficiency in the radioactive decontamination of porous materials, like bricks or concrete. The contaminated materials are sprayed with a mixture of polymer gel and wetting agent with nano-particulates in suspension. Under the action of the wetting agent, radioactivity migrates from the pores to the gel and is trapped by the nano-particulates. The drying and recycling of the gel allows to reduce the volume of radioactive wastes. Short paper. (J.S.)

  4. Exploratory experiments on the feasibility of Th and Pu sol-gel particles

    International Nuclear Information System (INIS)

    Vanhellemont, G.; Beullens, J.; Bairiot, H.

    1965-05-01

    The sol-gel process as developed by the O.E.C.D. Dragon Project has been applied by the Plutonium Project at Mol to determine the feasibility of producing spherical particles containing Th02, Pu02 and C, in the proportions necessary to fabricate thorium-plutonium carbide kernels for irradiation specimens and for fuel cartridges for the Dragon Reactor Experiment. The process has been extended successfully to the preparation of thorium and plutonium gels, having a significant excess of carbon, with the object of evaluating the feasibility of the sol-gel process for the production of Th, C-10 type kernels. Other experiments have been performed to test the feasibility of incorporating U02 powder into the gel spheres. By using this technique, U to Th ratios of up to 9:1 have been obtained. (author)

  5. Formulation of Bawang Dayak (Eleutherine bulbosa (Mill. Urb. Extract into a Gel Toothpaste

    Directory of Open Access Journals (Sweden)

    Husnul Warnida

    2016-12-01

    Full Text Available Dental caries is a disease of tooth decay that starts from the surface and evolve in the direction of the tooth, beginning with the process of tooth demineralization. Tooth decay is usually caused by the bacterium Streptococcus mutans. Bawang Dayak (Eleutherine bulbosa (Mill. Urb. has antibacterial activity due to its compound i.e. flavonoid, fenol, triterpenoid, dan antrakuinon. This study aims to formulate the bawang dayak ethanol extract into a stable gel toothpaste. Bawang dayak ethanol extract 2,5% was formulated in 5 formulas with varying degree of sorbitol (5 - 50% and carboxymethyl cellulose (3 - 7%. Physical stability of bawang dayak ethanol extract gel toothpastes were evaluated including organoleptic and homogeneity test, pH measurement, viscosity measurement, spreading test, and freeze-thaw cycling test. The result showed bawang dayak ethanol extract gel toothpastes have pH range of 5.50 - 5.80, spreading area 4.61 - 5.82, viscosity value 17066 - 99877 mPas. Organoleptic and homogeneity in 7 days showed two layers color of gel toothpaste. Consistency test and Freeze-thaw cycling test results showed no change in organoleptic, homogeneity, pH, and viscosity of gel toothpastes.

  6. Effect of ozonated oil and chlorhexidine gel on plaque induced gingivitis: A randomized control clinical trial.

    Science.gov (United States)

    Indurkar, Maya Sanjeev; Verma, Renu

    2016-01-01

    Several chemotherapeutic agents have been developed to prevent gingivitis and its progression into periodontitis. In this present study, the efficacy of ozonated oil and chlorhexidine gel was assessed and compared on plaque induced gingivitis. To evaluate the effect of ozonated oil on plaque induced gingivitis and to compare its efficacy with chlorhexidine gel. A total of 20 subjects, aged from 18 to 65 years, with plaque-induced gingivitis were selected from the outpatient Department of Periodontology, Government Dental College and Hospital, Aurangabad, for this study. They were divided randomly into the test or ozonated oil group (Group I) and the control or chlorhexidine gel group (Group II) with 10 subjects in each group. Subjects were randomly assigned to massage their gingiva thrice a day for 3 weeks with ozonated oil (test), and chlorhexidine gel (control). Plaque index and gingival index scores were recorded for the 20 subjects at baseline and after 3 weeks. Ozonated oil (Group I) and chlorhexidine gel (Group II) groups showed statistically significant differences with respect to plaque index and gingival index, from the baseline to 3 weeks (P plaque index and gingival index. The ozonated oil and chlorhexidine gel, both can be used as an effective agent in maintaining and improving gingival health.

  7. Effect of ozonated oil and chlorhexidine gel on plaque induced gingivitis: A randomized control clinical trial

    Directory of Open Access Journals (Sweden)

    Maya Sanjeev Indurkar

    2016-01-01

    Full Text Available Background: Several chemotherapeutic agents have been developed to prevent gingivitis and its progression into periodontitis. In this present study, the efficacy of ozonated oil and chlorhexidine gel was assessed and compared on plaque induced gingivitis. Aim: To evaluate the effect of ozonated oil on plaque induced gingivitis and to compare its efficacy with chlorhexidine gel. Materials and Methods: A total of 20 subjects, aged from 18 to 65 years, with plaque-induced gingivitis were selected from the outpatient Department of Periodontology, Government Dental College and Hospital, Aurangabad, for this study. They were divided randomly into the test or ozonated oil group (Group I and the control or chlorhexidine gel group (Group II with 10 subjects in each group. Subjects were randomly assigned to massage their gingiva thrice a day for 3 weeks with ozonated oil (test, and chlorhexidine gel (control. Plaque index and gingival index scores were recorded for the 20 subjects at baseline and after 3 weeks. Results: Ozonated oil (Group I and chlorhexidine gel (Group II groups showed statistically significant differences with respect to plaque index and gingival index, from the baseline to 3 weeks (P < 0.001 in both. But the difference between Group I and Group II, at the end of the study period, was not statistically significant with respect to the plaque index and gingival index. Conclusions: The ozonated oil and chlorhexidine gel, both can be used as an effective agent in maintaining and improving gingival health.

  8. Exploring the possible applications of catechin (gel for oral care of the elderly and disabled individuals

    Directory of Open Access Journals (Sweden)

    Muneaki Tamura

    2012-08-01

    Full Text Available The oral cavity contains more than hundreds of microbial species. An increase in the number of these microorganisms like high pathogenic potential species, such as cariogenic and periodontopathic bacteria, and the change of microbial biota may result in, not only oral infection, but also systemic diseases, such as infective endocarditis and aspiration pneumonia. It is very important to control the growth of these microorganisms and its biota just after oral cleaning in order to suppress disease onset. In this regard, it is useful to use the anti-microbial component which acts against pathogenic microorganisms. Here, we highlight the importance of catechin, and feature its possible oral, especially periodontal applications. By combining catechin with gel (catechin gel, antimicrobial activity of catechin was prolonged in gel and catechin anti-oxidization property was observed. Catechin gel inhibited the growth of the Actinomyces, periodontopathic bacteria and Candida strains tested, but did not inhibit that of the oral streptococci that are important in the normal oral flora. In contrast, commercially available moisture gels containing antimicrobial components showed antimicrobial activity against all of the tested strains including the oral streptococci. This show that catechin has selective antimicrobial activity, attributable to hydrogen peroxide production. This paper reviews previous works using catechin and, likewise, catechin gel may be show its possible oral application for prevent dental caries and periodontal disease.

  9. Nanotechnology in ligature-induced periodontitis: protective effect of a doxycycline gel with nanoparticules

    Directory of Open Access Journals (Sweden)

    Marco Antonio Botelho

    2010-08-01

    Full Text Available OBJECTIVES: The aim of this study was to test the efficacy of a locally applied 8.5% nanostructured doxycycline (DOX gel in preventing alveolar bone loss in experimental periodontal disease (EPD in rats by using the tapping mode atomic force microscopy (AFM. MATERIAL AND METHODS: EPD was induced in 24 Wistar rats. Animals were treated with the doxycycline gel topically, immediately after EPD induction, and 3 times a day during 11 days. Four groups (n=6 were formed as follows: Naïve group (animals not subjected to EPD nor treated; non-treated (NT group (animals subjected to EPD, but not treated; vehicle gel (VG group (animals subjected to EPD and treated with topical gel vehicle; and DOX group (test group: animals subjected to EPD and treated with the 8.5% DOX gel. In order to investigate topographical changes in histological sections, a novel simple method was used for sample preparation, by etching sections from paraffin-embedded specimens with xylol. RESULTS: Comparing the AFM images, several grooves were observed on the surface of the alveolar bone and other periodontal structures in the NT and VG groups, with significantly greater depths when compared to the DOX group (p<0.05. CONCLUSIONS: Periodontal structures were brought into high relief confirming to be a simple and cost-effective method for AFM imaging with ultrastructural resolution. The doxycycline gel was able to afford periodontal surface preservation, with flatter grooves.

  10. γ radiation induced changes in the bioadhesion properties of Ca-alginate gels

    International Nuclear Information System (INIS)

    Popeski-Dimovski, Riste

    2009-01-01

    The need for controlled release of drugs and their administration in specific zone of the organism asks for developing of carriers of drugs who will do the job. The two greatest needs, controlled release, and attention on the site, organ, of the organism that's treated its bioadhesion is best done with polymer gels. From the many choices of polymer gels, ether synthetic or natural the Na-alginate gels are the best suited because of their easy of access and good controlled release as being nontoxic to the living organisms and showing promising bioadhesion capability. Because of that examining the possibility for modification of the bioadhesion properties with gamma radiation is of interest. In this work Ca-alginate gels are irradiated with different absorbed doses to see if there will be any changes of the bioadhesion properties. For this mechanical compressibility tests and bioadhesion pull test are conducted on the irradiated samples. The results show that under irradiation gels louse their structural integrity becoming softer but the bioadhesive properties increase. But this increase is very small of up to 20% and its of no interest in practical circumstances where the practice is interested in changes of at least 100% and up, so changing the doses and properties of the gels to increase the bioadhesive properties might be of further interest. (Author)

  11. In vitro mutagenicity and genotoxicity study of 1,2-dichloroethylene, 1,1,2-trichloroethane, 1,3-dichloropropane, 1,2,3-trichloropropane and 1,1,3-trichloropropene, using the micronucleus test and the alkaline single cell gel electrophoresis technique (comet assay) in human lymphocytes.

    Science.gov (United States)

    Tafazoli, M; Kirsch-Volders, M

    1996-12-20

    The main objective of this study was to compare the cytotoxic genotoxic and mutagenic activity of a number of chlorinated aliphatic hydrocarbons, which are widely used as chemical intermediates, solvents, degreasing agents etc. in industry, and to establish the structure-toxicity relationship of the chemicals by using the most adequate determinants in estimating their toxicity. The mutagenicity and cytotoxicity of some of the candidate chemicals, namely 1,2-dichloroethylene, 1,1,2-trichloroethane, 1,3-dichloropropane, 1,2,3-trichloropropane and 1,1,3-trichloropropene were evaluated in an in vitro micronucleus assay. The cytokinesis-block methodology was applied on human lymphocytes in the presence or absence of an external metabolic activation system (S9-mix). In the micronucleus assay, all test substances, except 1,2,3-trichloropropane with and without S9-mix and 1,1,2-trichloroethane without S9-mix in the repeated experiment, exhibited a low but statistically significant mutagenic activity, compared to the concurrent control. However, none of the five chemicals was able to induce a clear and reproducible linear dose-dependent increase in micronucleus frequencies in this assay. Generally, mutagenic activity of the chemicals was found in the absence of severe cytotoxicity and/or cell cycle delay. The DNA breakage capacity and the cytotoxicity of these chemicals were also assessed in the alkaline single cell gel (SCG) electrophoresis test (comet assay) with and without S9-mix in isolated human lymphocytes. All chemical compounds induced DNA breakage, in the presence or absence of the metabolic activation system, at the doses tested. The data showed that the DNA reactivity of the chemicals increased with increasing degree of halogenation. The results of the present work suggested that the comet assay might be a more suitable and sensitive screening method than the micronucleus test for this particular class of compound. However, both assays do detect different

  12. Analysis of branched nucleic acid structure using comparative gel electrophoresis.

    Science.gov (United States)

    Lilley, David M J

    2008-02-01

    Electrophoresis in polyacrylamide gels provides a simple yet powerful means of analyzing the relative disposition of helical arms in branched nucleic acids. The electrophoretic mobility of DNA or RNA with a central discontinuity is determined by the angle subtended between the arms radiating from the branchpoint. In a multi-helical branchpoint, comparative gel electrophoresis can provide a relative measure of all the inter-helical angles and thus the shape and symmetry of the molecule. Using the long-short arm approach, the electrophoretic mobility of all the species with two helical arms that are longer than all others is compared. This can be done as a function of conditions, allowing the analysis of ion-dependent folding of branched DNA and RNA species. Notable successes for the technique include the four-way (Holliday) junction in DNA and helical junctions in functionally significant RNA species such as ribozymes. Many of these structures have subsequently been proved correct by crystallography or other methods, up to 10 years later in the case of the Holliday junction. Just as important, the technique has not failed to date. Comparative gel electrophoresis can provide a window on both fast and slow conformational equilibria such as conformer exchange in four-way DNA junctions. But perhaps the biggest test of the approach has been to deduce the structures of complexes of four-way DNA junctions with proteins. Two recent crystallographic structures show that the global structures were correctly deduced by electrophoresis, proving the worth of the method even in these rather complex systems. Comparative gel electrophoresis is a robust method for the analysis of branched nucleic acids and their complexes.

  13. Evaluation of an ambient air sampling system for tritium (as tritiated water vapor) using silica gel adsorbent columns

    International Nuclear Information System (INIS)

    Patton, G.W.; Cooper, A.T.; Tinker, M.R.

    1995-08-01

    Ambient air samples for tritium analysis (as the tritiated water vapor [HTO] content of atmospheric moisture) are collected for the Hanford Site Surface Environmental Surveillance Project (SESP) using the solid adsorbent silica gel. The silica gel has a moisture sensitive indicator which allows for visual observation of moisture movement through a column. Despite using an established method, some silica gel columns showed a complete change in the color indicator for summertime samples suggesting that breakthrough had occurred; thus a series of tests was conducted on the sampling system in an environmental chamber. The purpose of this study was to determine the maximum practical sampling volume and overall collection efficiency for water vapor collected on silica gel columns. Another purpose was to demonstrate the use of an impinger-based system to load water vapor onto silica gel columns to provide realistic analytical spikes and blanks for the Hanford Site SESP. Breakthrough volumes (V b ) were measured and the chromatographic efficiency (expressed as the number of theoretical plates [N]) was calculated for a range of environmental conditions. Tests involved visual observations of the change in the silica gel's color indicator as a moist air stream was drawn through the column, measurement of the amount of a tritium tracer retained and then recovered from the silica gel, and gravimetric analysis for silica gel columns exposed in the environmental chamber

  14. Preparation of demipermanent and semipermanent hair dyes gels from ethanol extract of Caesalpinia sappan L. using carbomer as gelling agent

    Science.gov (United States)

    Indrawati, T.; Syahrin, A.; Irpan

    2017-07-01

    Caesalpinia sappan L. (Cs L) contains of essential oils, saponin, brazilin, brazilein, alkaloids, flavonoids and tannins that have a function as cationic natural dyes. The aim of this research was to prepare the ethanol extract of Cs L wood and to prepare demi-permanent and semi-permanent of hair dye gels by using Carbomer of 2 % and 1.5 % as gelling agent and Cs L extract as cationic dyes. The Extract of Cs L was macerated by using ethanol of 96 % as the solvent, and then thickened. Three formula of demi-permanent hair dye gels were made by using Cs L extract of 3 %, 6% and 9 %. Three formula of semi-permanent hair dye gels were made by using Cs L extract of 2.50 %, 7.00 % and 10.50 %. Those hair dyes gels were prepared by swelling and mixing methods. All products of hair dyes gels were evaluated with organoleptic test, homogeneity test, pH test, consistency test, rheological properties test and dyeing effect test. The demi-permanent hair dye gels products had brown to brown dark black colors, pH of 5.05-5.43, homogeny, specific Cs L odor, and had pseudoplastic thixotropic flow characteristic. The semi-permanent hair dye gels products had red color pH of 6.5-6.25, homogeny, Cs L odor, and have pseudoplastic thixotropic flow characteristics. The optimum formula of demi-permanent was formula gel that contained of 6 % extract of Cs L and the optimum formula of permanent hair dyes gel was formula that contained of 10.50 % extract of Cs L.

  15. Evolution of gel structure during thermal processing of Na-geopolymer gels.

    Science.gov (United States)

    Duxson, Peter; Lukey, Grant C; van Deventer, Jannie S J

    2006-10-10

    The present work examines how the gel structure and phase composition of Na-geopolymers derived from metakaolin with varied Si/Al ratio evolve with exposure to temperatures up to 1000 degrees C. Gels were thermally treated and characterized using quantitative XRD, DTA, and FTIR to elucidate the changes in gel structure, phase composition, and porosity at each stage of heating. It is found that the phase stability, defined by the amount and onset temperature of crystallization, is improved at higher Si/Al ratios. Two different mechanisms of densification have been isolated by FTIR, related to viscous flow and collapse of the highly distributed pore network in the gel. Gels with low Si/Al ratio only experience viscous flow that correlates with low thermal shrinkage. Gels at a higher Si/Al ratio, which have a homogeneous microstructure composed of a highly distributed porosity, undergo both densification processes corresponding to a large extent of thermal shrinkage during densification. This work elucidates the intimate relationship between gel microstructure, chemistry, and thermal evolution of Na-geopolymer gels.

  16. Development of an in vitro Endotoxin Test for Monoolein–Water ...

    African Journals Online (AJOL)

    Purpose: Drugs that are administered by parenteral route must be apyrogenic. The aim of this study was to develop an in vitro endotoxin test for liquid crystalline gels for use as implants, using a monoolein–water liquid crystalline gel as a model. Methods: The gel-clot technique was used. The gel was dissolved first in ...

  17. Physical and chemical properties of gels. Application to protein nucleation control in the gel acupuncture technique

    Science.gov (United States)

    Moreno, Abel; Juárez-Martínez, Gabriela; Hernández-Pérez, Tomás; Batina, Nikola; Mundo, Manuel; McPherson, Alexander

    1999-09-01

    In this work, we present a new approach using analytical and optical techniques in order to determine the physical and chemical properties of silica gel, as well as the measurement of the pore size in the network of the gel by scanning electron microscopy. The gel acupuncture technique developed by García-Ruiz et al. (Mater. Res. Bull 28 (1993) 541) García-Ruiz and Moreno (Acta Crystallogr. D 50 (1994) 484) was used throughout the history of crystal growth. Several experiments were done in order to evaluate the nucleation control of model proteins (thaumatin I from Thaumatococcus daniellii, lysozyme from hen egg white and catalase from bovine liver) by the porous network of the gel. Finally, it is shown how the number and the size of the crystals obtained inside X-ray capillaries is controlled by the size of the porous structure of the gel.

  18. Mucosal effects of tenofovir 1% gel.

    Science.gov (United States)

    Hladik, Florian; Burgener, Adam; Ballweber, Lamar; Gottardo, Raphael; Vojtech, Lucia; Fourati, Slim; Dai, James Y; Cameron, Mark J; Strobl, Johanna; Hughes, Sean M; Hoesley, Craig; Andrew, Philip; Johnson, Sherri; Piper, Jeanna; Friend, David R; Ball, T Blake; Cranston, Ross D; Mayer, Kenneth H; McElrath, M Juliana; McGowan, Ian

    2015-02-03

    Tenofovir gel is being evaluated for vaginal and rectal pre-exposure prophylaxis against HIV transmission. Because this is a new prevention strategy, we broadly assessed its effects on the mucosa. In MTN-007, a phase-1, randomized, double-blinded rectal microbicide trial, we used systems genomics/proteomics to determine the effect of tenofovir 1% gel, nonoxynol-9 2% gel, placebo gel or no treatment on rectal biopsies (15 subjects/arm). We also treated primary vaginal epithelial cells from four healthy women with tenofovir in vitro. After seven days of administration, tenofovir 1% gel had broad-ranging effects on the rectal mucosa, which were more pronounced than, but different from, those of the detergent nonoxynol-9. Tenofovir suppressed anti-inflammatory mediators, increased T cell densities, caused mitochondrial dysfunction, altered regulatory pathways of cell differentiation and survival, and stimulated epithelial cell proliferation. The breadth of mucosal changes induced by tenofovir indicates that its safety over longer-term topical use should be carefully monitored.

  19. Comparative Two-Dimensional Fluorescence Gel Electrophoresis.

    Science.gov (United States)

    Ackermann, Doreen; König, Simone

    2018-01-01

    Two-dimensional comparative fluorescence gel electrophoresis (CoFGE) uses an internal standard to increase the reproducibility of coordinate assignment for protein spots visualized on 2D polyacrylamide gels. This is particularly important for samples, which need to be compared without the availability of replicates and thus cannot be studied using differential gel electrophoresis (DIGE). CoFGE corrects for gel-to-gel variability by co-running with the sample proteome a standardized marker grid of 80-100 nodes, which is formed by a set of purified proteins. Differentiation of reference and analyte is possible by the use of two fluorescent dyes. Variations in the y-dimension (molecular weight) are corrected by the marker grid. For the optional control of the x-dimension (pI), azo dyes can be used. Experiments are possible in both vertical and horizontal (h) electrophoresis devices, but hCoFGE is much easier to perform. For data analysis, commercial software capable of warping can be adapted.

  20. Synergetic effect of green tea on polymer gel dosimeter and determination of optimal wavelength to choose light source for optical computed tomography

    Directory of Open Access Journals (Sweden)

    Sathiya Raj

    2016-03-01

    Full Text Available Purpose: The ultimate aim of this study is to observe the effect of Green tea as a co-antioxidant in PAGAT gel dosimeter and evaluate the appropriate light source for scanning the PAGAT and NIPAM polymer gel.Methods: Both PAGAT (Poly Acrylamide Gelatin Tetrakis hydroxyl phosphonium chloride and NIPAM (N-Isopropyl acrylamide gel were prepared in normoxic condition. The green tea extract (GTE was prepared and tested only on PAGAT. Co-60 teletherapy machine has been used for irradiation purpose, and the gel samples were scanned using UV-Visible spectrophotometer. Water equivalency of the gel has been tested in terms of their electron density, effective atomic number and Ratio of oxygen and hydrogen (O/H. We have used NIST XCOM database to test the water equivalency.Results: In this study we found that the GTE added to the gel do not respond to the given doses. By adding sugar we can enhance the sensitivity of the gel. Further investigations are required to use Green tea as a co antioxidant concentration of THPC (Tetrakis hydroxymethyl phosphonium chloride. The optimal wavelength with different region for scanning the PAGAT is 450 to 480 nm (Blue region, for NIPAM it is 540 nm and 570 nm (Green and yellow region. The PAGAT and NIPAM showed better sensitivity at 510 nm. Both gels have their effective atomic number closer to water (NIPAM-7.2, PAGAT-7.379.Conclusion: As per our results, we concluded that GTE alone is not an effective co-antioxidant for polymer gels. When the GTE is combined with sugar and THPC, it protects the gel from pre-polymerization. This study strongly suggests that the blue light is an optimal source for scanning the PAGAT and green to yellow light for NIPAM gel. Though both gels were considered as water equivalent, the PAGAT is equivalent to water and the temporal stability of this gel is higher than NIPAM.

  1. Adsorption and Desorption of Na+ and NO3− Ions on Thermosensitive NIPAM-co-DMAAPS Gel in Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Eva Oktavia Ningrum

    2017-11-01

    Full Text Available Adsorbent gel with the ability to absorb and to desorb Na+ and NO3− ions simultaneously with temperature swing was synthesized by free radical copolymerization reaction of N-isopropylacrylamide (NIPAM and N,N-dimethyl-(acrylamidopropylammonium propane sulfonate (DMAAPS. In this study, NIPAM acts as a thermosensitive agent and DMAAPS as an adsorbent agent. The purpose of this research is to investigate the effect of temperature and solution concentration on the swelling, adsorption, and desorption behaviors of NIPAM-co-DMAAPS gel. The relationship between adsorption and desorption behaviors of the gel was also elucidated. NaNO3 solution was selected as the target solution in swelling, adsorption, and desorption test. It was observed that the swelling degree of the gel increased as temperature and solution concentration raised. The adsorption amount of ions decreased with the increase of temperature. In contrast, the amount of ions desorbed from the gel increased linearly with temperature.

  2. FORMULASI GEL ANTIOKSIDAN EKSTRAK KULIT BUAH MANGGIS (Garcinia mangostana L dengan BASIS CARBOPOL

    Directory of Open Access Journals (Sweden)

    Supomo

    2016-03-01

    Full Text Available The skin of the mangosteen fruit (Garcinia mangostana L. contains xanthones which is a powerful antioxidant. Antioxidants are substances that neutralize free radicals that can protect the body from the biological system adverse effects arising from the process or reaction that causes excessive oxidation. The purpose of this study is to formulate extract of mangosteen rind with a particular concentration in the form of gel formulation of antioxidants and determine physical and chemical properties. The research is experimental research. Object studied is mangosteen rind extract (Garcinia mangostana L. were extracted using maceration. Formula made with mevariasikan 3 concentration of the ethanol extract of mangosteen rind 0.2%, 0.4%, and 0.6% use a gelling agent carbopol 940 0.5%. Tests carried out on organoleptic gel formulation (odor, color, texture, homogeneity, pH, skin irritation, and the gel dispersive power of antioxidants. Results of testing physical properties, gel ethanol extract of mangosteen rind using a base of carbopol 940 in formula I with a concentration of 0.2% extract of yellow vaginal discharge, formula II with a 0.4% concentration of yellow-brown, formula III with a concentration of 0.6% yellow brown and smelled each formula oleum citri and smooth creamy texture, has a pH value of 6 with good homogeneity and does not irritate. Dispersive power generated at each antioxidant gel formula has a value that does not meet the requirements of the spread. From this study it can be concluded that the ethanol extract of the skin of the mangosteen fruit (Garcinia mangostana L. can be formulated as a gel antioxidants. The best antioxidant gel formula is the formula I with a 0.2% concentration of the extracts from the results of testing physical properties are quite stable and has a color more transparent.

  3. Confocal Rheology Probes the Structure and Mechanics of Collagen through the Sol-Gel Transition.

    Science.gov (United States)

    Tran-Ba, Khanh-Hoa; Lee, Daniel J; Zhu, Jieling; Paeng, Keewook; Kaufman, Laura J

    2017-10-17

    Fibrillar type I collagen-based hydrogels are commonly used in tissue engineering and as matrices for biophysical studies. Mechanical and structural properties of these gels are known to be governed by the conditions under which fibrillogenesis occurs, exhibiting variation as a function of protein concentration, temperature, pH, and ionic strength. Deeper understanding of how macroscopic structure affects viscoelastic properties of collagen gels over the course of fibrillogenesis provides fundamental insight into biopolymer gel properties and promises enhanced control over the properties of such gels. Here, we investigate type I collagen fibrillogenesis using confocal rheology-simultaneous confocal reflectance microscopy, confocal fluorescence microscopy, and rheology. The multimodal approach allows direct comparison of how viscoelastic properties track the structural evolution of the gel on fiber and network length scales. Quantitative assessment and comparison of each imaging modality and the simultaneously collected rheological measurements show that the presence of a system-spanning structure occurs at a time similar to rheological determinants of gelation. Although this and some rheological measures are consistent with critical gelation through percolation, additional rheological and structural properties of the gel are found to be inconsistent with this theory. This study clarifies how structure sets viscoelasticity during collagen fibrillogenesis and more broadly highlights the utility of multimodal measurements as critical test-beds for theoretical descriptions of complex systems. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  4. Evaluation of an Experimental Gel Containing Euclea natalensis: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Sílvia Helena de Carvalho Sales-Peres

    2012-01-01

    Full Text Available Objective. To evaluate the effect of an experimental gel containing Euclea natalensis extract on dentin permeability. Methods. Thirty-six dentin discs, 1-mm-thick. The discs were prepared from the coronal dentin of extracted human third molars that were divided into 3 groups (. The dentin discs in each group were treated with the groups following experimental materials: (FG: 1.23% fluoride gel, pH 4.1; (EG: Euclea natalensis extract gel, pH 4.1; (CG: control gel, pH 4.1. The gels were applied to the occlusal slide of the dentin under the following conditions: after 37% phosphoric acid and before 6% citric acid. The hydraulic conductance (HC of each condition was determined four times using a fluid flow apparatus (Flodec. The data were analyzed using Two-way ANOVA and Tukey's test (. Results. The greatest mean reduction in HC was produced in group EG dentin discs (61.2%; . Even after acid challenge with 6% citric acid the great reduction occurred in group EG (66.0%; than other groups (CG-77.1%, FG-90.8%. Conclusion. E. natalensis gel not only reduced dentin permeability, but also resisted posttreatment citric acid challenge without changing its permeability. Further research has to confirm this promising result in the clinical situation.

  5. The effect of Emdogain gel on periodontal healing in replanted monkeys' teeth.

    Science.gov (United States)

    Lam, Karen; Sae-Lim, Varawan

    2004-01-01

    We sought to histologically evaluate the effect of Emdogain gel on periodontal healing in monkeys' teeth undergoing delayed replantation. Study design Mature monkey teeth simulating avulsion were endodontically treated before extraction. Negative control teeth (group N = 10 roots) underwent immediate replantation, whereas the rest were bench-dried for 1 hour and treated in one of the following ways before replantation: the positive control teeth (group P = 12 roots) had no further treatment; group C teeth (4 roots) had the periodontal ligament removed; group D teeth (10 roots) were treated with Emdogain gel; group E teeth (6 roots) had the periodontal ligament removed before the application of Emdogain gel; and group F teeth (7 roots) had the periodontal ligament removed, the root surface conditioned, and Emdogain gel applied. Periodontal healing was evaluated after 16 weeks by undertaking histomorphometric analysis. The Kruskal-Wallis and Mann-Whitney U tests revealed that group N teeth had a statistically higher occurrence of complete healing than did all other groups, whereas group P was not significantly different in any of the healing categories from D, E, and F, the groups in which Emdogain gel was used. Group C teeth had a significantly higher occurrence of replacement root resorption than did the teeth in groups P and F-but were not significantly different from teeth in groups D and E. Emdogain gel did not appear to significantly reduce replacement resorption in monkeys' teeth that had undergone delayed replantation.

  6. Poloxamer-hydroxyethyl cellulose-α-cyclodextrin supramolecular gels for sustained release of griseofulvin.

    Science.gov (United States)

    Marcos, Xelhua; Pérez-Casas, Silvia; Llovo, José; Concheiro, Angel; Alvarez-Lorenzo, Carmen

    2016-03-16

    Supramolecular gels of poloxamer-hydroxyethyl cellulose (HEC)-α-cyclodextrin (αCD) were developed aiming to obtain synergisms regarding solubilization and sustained release of griseofulvin for topical application. The effects of αCD concentration (0-10%w/w) on the phase behavior of aqueous dispersions of Pluronic(®) P123 (14%w/w) mixed with HEC (2%w/w) were evaluated at 4, 20 and 37°C. The cooperative effects of the inclusion complex formation between poly(ethylene oxide) (PEO) blocks and HEC with αCD prevented phase separation and led to supramolecular networks that solubilize the antifungal drug. Rheological and bioadhesive properties of gels with and without griseofulvin could be easily tuned modulating the polymers proportions. Supramolecular gels underwent sol-gel transition at lower temperature than P123 solely dispersions and enabled drug sustained release for at least three weeks. All gels demonstrated good biocompatibility in the HET-CAM test. Furthermore, the drug-loaded gels showed activity against Trichophyton rubrum and Trichophyton mentagrophytes and thus may be useful for the treatment of tinea capitis and other cutaneous fungal infections. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Preparation and evaluation of bioadhesive benzocaine gels for enhanced local anesthetic effects.

    Science.gov (United States)

    Shin, Sang-Chul; Lee, Jin-Woo; Yang, Kyu-Ho; Lee, Chi H

    2003-07-09

    This study was performed to develop new enhanced anesthetic benzocaine gels with a suitable bioadhesive property for local anesthetic effects. As the concentration of benzocaine in the HPMC gels increased up to 15%, the permeation of drug increased, thereafter slightly increased. The activation energy of drug permeation was 11.29 kcal/mol. Bioadhesive forces were also measured. The permeation rate of drug through the skin was studied using various enhancers, such as glycols, non-ionic surfactants or fatty acids. Among the enhancers used, diethylene glycol showed the most enhancing effects. Analgesic activity was examined using a tail-flick analgesimeter. According to the rat tail-flick test, the value of AUEC (0 - 360min) of 15% benzocaine gels containing diethylene glycol was 4662 +/- 200 s min, while that of gels without diethylene glycol was 3353 +/- 132 s min, showing about 1.39-fold increase in analgesic activity. Fifteen percentage of benzocaine gels containing diethylene glycol showed the most enhanced, prolonged analgesic effects, showing the maximum anesthetic effects at 240 min, while the gels without diethylene glycol showed maximum effect at 180 min.

  8. Modified sol-gel coatings for biotechnological applications

    Energy Technology Data Exchange (ETDEWEB)

    Beganskiene, A [Department of General and Inorganic Chemistry, Vilnius University, Vilnius LT-03225 (Lithuania); Raudonis, R [Department of General and Inorganic Chemistry, Vilnius University, Vilnius LT-03225 (Lithuania); Jokhadar, S Zemljic [Faculty of Medicine, Institute of Biophysics, Lipiceva 2, Ljubljana SI-1000 (Slovenia); Batista, U [Faculty of Medicine, Institute of Biophysics, Lipiceva 2, Ljubljana SI-1000 (Slovenia); Kareiva, A [Department of General and Inorganic Chemistry, Vilnius University, Vilnius LT-03225 (Lithuania)

    2007-12-15

    The modified sol-gel derived silica coatings were prepared and characterized. The amino and methyl groups were introduced onto the colloidal silica. The silica coatings with different wettability properties: coloidal silica (water contact angle 17 deg.), polysiloxane (61 deg.), methyl-modified (158 deg. and 46 deg.) coatings samples were tested for CaCo-2 cells proliferation. Methyl-modified coating (46 deg.) proved to be the best substrate for cell proliferation. CaCo-2 cell proliferation two days post seeding was significantly faster on almost laminine, fibronectin and collagen-1 coated samples compared to corresponding controls.

  9. Effect of setting with various temperatures on gel forming properties of farmed carp (Cyprinus carpio surimi

    Directory of Open Access Journals (Sweden)

    SH Zamaninejad

    2015-05-01

    Full Text Available Freshwater aquaculture especially hydrothermal fish is increased in recent years. In Chinese carp aquaculture, common carp (CyprinusCarpiocomprises the 15-20 percent of the aquaculture system. Foods obtained from farmed carps could be turn into value-added and ready to eat products such as sausages, salami, burgers and etc. Surimi is one of the intermediate products to make ready to eat foods. Texture properties of surimi products depend mainly on its gelation ability. Through basic preparation of fish paste (setting for last cooking it would be possible to produce stronger gels. In this research the effect of high and low temperature setting on gelation characteristics of farmed common carp surimi wasinvestigated. For this end, control, kamaboko and suwari treatments were considered. Suwari and kamaboko gels were located at 35°C for 1 hour followed by storage at 4 °C for 12 hours. After setting the suwari gels were cooled,however kamaboko gels were cooked prior to cooling.All samples were examined for water holding capacity, protein solubility, soluble peptides, gel electrophoresis (SDS-PAGE, puncture test and color evaluation. According to the results the lowest rate of whiteness and L* indices were observed in control group. Set gels at 35 °C demonstrated the highest strength, water holding capacity and soluble peptides in TCA and also had the lowest protein solubility and molecule weight of myosin. The results showed that set gels in high temperature results in better physicochemical properties than the gels set at low temperature.

  10. Duration of Fipronil and Imidacloprid Gel Baits Toxicity against Blattella germanica Strains of Iran

    Directory of Open Access Journals (Sweden)

    H Nasirian

    2007-12-01

    Full Text Available The current study was conducted to investigate the duration of fipronil and imidacloprid gel baits toxicity against Ger-man cockroach strains in Iran during 2003-2004. In order to conduct this study, nine German cockroach strains were used. Newly emerged adult male German cockroaches starved for one scotophase (12 h, and ingested fipronil and imidacloprid gel baits for 2 h. After the given time was over, the bait was removed and replaced with mouse pellet. Mortality was re-corded at 12 intervals for 144 h (6 days. Mortality data of the replicates were pooled and was tested using probit analysis. Both gel baits were toxic to adult male German cockroaches. In the ingested bait method, the susceptible strain showed LT50 of 47.1 and 11.3 h for fipronil and imidacloprid gel baits, respectively, and the average LT90 was 74.2 and 19.3 h, respec¬tively. LT50 of the feral German cockroach strains varied 14.9 h from 30.5 to 45.4 h and 4.4 h from 12.4 to 16.8 h for fipronil and imidacloprid gel baits, respectively. All German cockroach strains showed a similar susceptibility to fipronil and imidacloprid gel baits, compared with the susceptible laboratory strain. The steep slopes of ingested bait mortality curves indicated that the feral German cockroach strains were homogenous to fipronil and imidacloprid ingested gel baits. These results suggest that fipronil and imidacloprid gel baits appear to have considerable potential as a bait for insecticide-resistant strains of German cockroach.

  11. Exploring encapsulation mechanism of DNA and mononucleotides in sol-gel derived silica.

    Science.gov (United States)

    Kapusuz, Derya; Durucan, Caner

    2017-07-01

    The encapsulation mechanism of DNA in sol-gel derived silica has been explored in order to elucidate the effect of DNA conformation on encapsulation and to identify the nature of chemical/physical interaction of DNA with silica during and after sol-gel transition. In this respect, double stranded DNA and dAMP (2'-deoxyadenosine 5'-monophosphate) were encapsulated in silica using an alkoxide-based sol-gel route. Biomolecule-encapsulating gels have been characterized using UV-Vis, 29 Si NMR, FTIR spectroscopy and gas adsorption (BET) to investigate chemical interactions of biomolecules with the porous silica network and to examine the extent of sol-gel reactions upon encapsulation. Ethidium bromide intercalation and leach out tests showed that helix conformation of DNA was preserved after encapsulation. For both biomolecules, high water-to-alkoxide ratio promoted water-producing condensation and prevented alcoholic denaturation. NMR and FTIR analyses confirmed high hydraulic reactivity (water adsorption) for more silanol groups-containing DNA and dAMP encapsulated gels than plain silica gel. No chemical binding/interaction occurred between biomolecules and silica network. DNA and dAMP encapsulated silica gelled faster than plain silica due to basic nature of DNA or dAMP containing buffer solutions. DNA was not released from silica gels to aqueous environment up to 9 days. The chemical association between DNA/dAMP and silica host was through phosphate groups and molecular water attached to silanols, acting as a barrier around biomolecules. The helix morphology was found not to be essential for such interaction. BET analyses showed that interconnected, inkbottle-shaped mesoporous silica network was condensed around DNA and dAMP molecules.

  12. Heat-induced whey protein gels: protein-protein interactions and functional properties.

    Science.gov (United States)

    Havea, Palatasa; Watkinson, Philip; Kuhn-Sherlock, Barbara

    2009-02-25

    Heat-induced gelation (80 degrees C for 30 min or 85 degrees C for 60 min) of whey protein concentrate (WPC) solutions was studied using small deformation dynamic rheology, small and large deformation compression, and polyacrylamide gel electrophoresis (PAGE). The WPC solutions (15% w/w, pH 6.9) were prepared by dispersing WPC powder in water (control), 1% (w/w) sodium dodecyl sulfate (SDS) solution, and N-ethylmaleimide (NEM) solution at a protein/NEM molar ratio of 1:1 or in 10 mM dithiothreitol (DTT) solution. PAGE analyses showed that the heat treatment of control solutions contained both disulfide and non-covalent linkages between denatured protein molecules. Only disulfide linkages were formed in heated SDS-WPC solutions, whereas only non-covalent linkages were formed in DTT-WPC and NEM-WPC solutions during heating. In heated NEM-WPC solutions, the pre-existing disulfide linkages remained unaltered. Small deformation rheology measurements showed that the storage modulus (G') values, compared with those of the control WPC gels (approximately 14000 Pa), were 3 times less for the SDS-WPC gels (approximately 4000 Pa), double for the NEM-WPC gels (approximately 24000 Pa), and even higher for the DTT-WPC gels (approximately 30000 Pa). Compression tests suggested that the rubberiness (fracture strain) of the WPC gels increased as the degree of disulfide linkages within the gels increased, whereas the stiffness (modulus) of the gels increased as the degree of non-covalent associations among the denatured protein molecules increased.

  13. Elasticity and clustering in concentrated depletion gels.

    Science.gov (United States)

    Ramakrishnan, S; Chen, Y-L; Schweizer, K S; Zukoski, C F

    2004-10-01

    X-ray scattering and rheology are employed to study the volume fraction dependence of the collective structure and elastic moduli of concentrated nanoparticle-polymer depletion gels. The nonequilibrium gel structure consists of locally densified nonfractal clusters and narrow random interfaces. The elastic moduli display a power law dependence on volume fraction with effective exponents that decrease with increasing depletion attraction strength. A microscopic theory that combines local structural information with a dynamic treatment of gelation is in good agreement with the observations.

  14. Recubrimientos de hidroxiapatita preparados mediante un proceso sol-gel

    Directory of Open Access Journals (Sweden)

    Peón, E.

    2005-12-01

    Full Text Available Hydroxyapatite coatings (HAp have been obtained starting from precursors of sol-gel type. The coatings previously oxidized were deposited on metal surfaces of a based on iron alloy so-called MA956. The alloys were at high temperatures, in order to improve the adhesion with the hydroxyapatite coatings. The sol-gel coating was obtained applying an aqueous route, using triethyl phosphite and aqueous calcium nitrate, as precursors of phosphorous and calcium, respectively. Different sintering thermal treatments were applied on the resulting gels in order to obtain a homogeneous, adherent and crystalline hydroxyapatite coating. The characterization techniques used for this study were optical microscopy, SEM/EDX, XDR and FTIR. Moreover, the adhesion between the hydroxylapatite coating and the substrate was assessed according to the ASTM D 3359-02 standard test method. The results of this study showed that the best thermal treatment is obtained for a sintering temperature of 550 °C during a time of 72 h.

    Se han preparado nuevos recubrimientos de hidroxiapatita (HAp obtenidos a partir de precursores de tipo sol-gel, depositados sobre sustratos metálicos de una aleación de base hierro denominada MA956, previamente oxidados a elevadas temperaturas, para mejorar la adherencia con los recubrimientos de hidroxiapatita. El recubrimiento sol-gel se obtuvo aplicando una ruta acuosa, utilizando como precursores del fósforo y del calcio trietilfosfito y nitrato cálcico tetrahidratado, respectivamente. Sobre los geles resultantes se aplicaron distintos tratamientos térmicos de sinterización, hasta la obtención de recubrimientos de hidroxiapatita homogéneos, adherentes y cristalinos. Las técnicas de caracterización utilizadas para realizar este estudio han sido microscopía óptica, MBE/EDX, DRX y FTIR. Así mismo, se ha determinado la adherencia entre el substrato y el recubrimiento de hidroxiapatita según la norma ASTM D 3359-02. Los resultados

  15. Pouring and running a protein gel by reusing commercial cassettes.

    Science.gov (United States)

    Hwang, Alexander C; Grey, Paris H; Cuddy, Katrina; Oppenheimer, David G

    2012-02-12

    The evaluation of proteins using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis is a common technique used by biochemistry and molecular biology researchers. For laboratories that perform daily analyses of proteins, the cost of commercially available polyacrylamide gels (~$10/gel) can be considerable over time. To mitigate this cost, some researchers prepare their own polyacrylamide gels. Traditional methods of pouring these gels typically utilize specialized equipment and glass gel plates that can be expensive and preclude pouring many gels and storing them for future use. Furthermore, handling of glass plates during cleaning or gel pouring can result in accidental breakage creating a safety hazard, which may preclude their use in undergraduate laboratory classes. Our protocol demonstrates how to pour multiple protein gels simultaneously by recycling Invitrogen Nupage Novex minigel cassettes, and inexpensive materials purchased at a home improvement store. This economical and streamlined method includes a way to store the gels at 4°C for a few weeks. By re-using the plastic gel cassettes from commercially available gels, labs that run frequent protein gels can save significant costs and help the environment. In addition, plastic gel cassettes are extremely resistant to breakage, which makes them ideal for undergraduate laboratory classrooms.

  16. [Use of an immunodiffusion analysis method in micrococcus species determination].

    Science.gov (United States)

    Ivshina, I B; Gvozdiak, O R; Bogomiagkova, O A; Shkaruba, V V

    1995-01-01

    Eight species of the genus Micrococcus were studied in details for their antigenic specificities with the aid of the created bank of specific polyclonal antisera to the type strains of Micrococcus Cohn 1872--M. luteus CCM 169, M. varians CCM 884, M. roseus CCM 679 and M. nishinomiyaensis CCM 2140. Immunochemical analysis of 146 strains isolated from various natural and industrial substrata, as well as of 31 collection strains allowed us to reveal antigenic relatedness and distinctions between studied cultures and to accomplish taxonomic distribution of various Micrococcus species. By the immunoduffusion analysis the intraspecific antigenic relationship of M. roseus and M. varians was found, as well as significant antigenic heterogeneity of M. luteus. The results of antigenic analysis of micrococci may be used in the collection work and for the express-diagnostics of these microorganisms.

  17. Daya Repelan Gel Minyak Atsiri Bunga Kenanga (Cananga Odorata (Lmk) Hook.f & Thoms) Dalam Basis Carbopol, Terhadap Nyamuk Aedes Aegypti

    OpenAIRE

    Kurniawati, Linda; Hapsari, Indri; Hartanti, Dwi

    2010-01-01

    The aim of this research is to know the influence of carbopol concentration to physical characteristic and repellency of cananga flowers volatile oil in carbopol gel base. Cananga flowers volatile oil was extracted by steam water destilation. Three formulas of gel were made by various carbopol concentration (0,5 g, 1,0 g and 1,5 g). The gels produced were tested physical characteristic (organoleptic, pH, viscosity, homogeneity, spread ability, adhesive ability and identification of cananga fl...

  18. Eliminating blurry bands in gels with a simple cost-effective repair to the gel cassette.

    Science.gov (United States)

    Bingaman, Jamie L; Frankel, Erica A; Hull, Chelsea M; Leamy, Kathleen A; Messina, Kyle J; Mitchell, David; Park, Hongmarn; Ritchey, Laura E; Babitzke, Paul; Bevilacqua, Philip C

    2016-12-01

    Gel electrophoresis and subsequent imaging using phosphorimagers is one of the most important and widely used techniques in RNA and DNA analysis. Radiolabeling nucleic acids with 32 P and detecting bands using a phoshorimager are useful both in a qualitative sense for nucleic acid detection and in a quantitative sense for structural, kinetic, or binding-based assays. Because of this, good resolution of gel bands based on molecular weight and size of RNA or DNA is essential for analysis. The appearance of blurry gel bands of 32 P-labeled RNA and DNA thus represents a serious problem in the laboratory. A quick search on the Internet uncovers numerous reports begrudging the appearance of blurry bands, as well as attempts to fix them without success. Indeed, our laboratories were beset by the intermittent problem of blurry gels for over one year before we found a solution. Herein we describe a simple and cost-effective solution to a problem that we show originates from the phosphorimager cassettes rather than the integrity of the gel itself. We hope that the information provided here will lead to immediate help for other laboratories experiencing similar issues with labeled nucleic acid gel-based assays. The improvement in the clarity of the gels is nothing short of astonishing in many instances and will lead to higher resolution images for analysis and publications. © 2016 Bingaman et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  19. Synthesis and Test of 'New' Gel-Type Lithium Electrolytes

    National Research Council Canada - National Science Library

    Scrosati, Bruno

    1994-01-01

    In this 6th two-month period we have continued the characterization of PMMA-based electrolyte membranes by examining the phenomena occurring at the interface between these membranes and the lithium...

  20. LABORATORY-SCALE PRODUCTION OF ADU GELS BY EXTERNAL GELATION FOR AN INTERMEDIATE HTGR NUCLEAR

    Directory of Open Access Journals (Sweden)

    S Simbolon

    2015-03-01

    Full Text Available LABORATORY-SCALE PRODUCTION OF ADU GELS BY EXTERNAL GELATION FOR AN INTERMEDIATE HTGR NUCLEAR. The The aim of this research is to produce thousands of microsphere ADU (Ammonium Diuranate gels by using external gelation for an intermediate HTGR (High Temperature Gas-cooled Reactor nuclear fuel in laboratory-scale. Microsphere ADU gels were based on sol-solution which was made from a homogeneous mixture of ADUN (Acid Deficient Uranyl Nitrate which was containing uranyl ion in high concentration, a water soluble organic compound PVA (Polyvinyl Alcohol and THFA (Tetrahydrofurfuryl Alcohol. The simple unified home made laboratory experimental machine was developed to replace test tube experiment method which was once used due to a tiny amount of microsphere ADU gels produced. It consists of four main parts: tank filled sol-solution connecting to peristaltic pump and vibrating nozzle, preliminary gelation and gelation column. The machine has successfully converted 150 mL sol-solution into thousands of drops which produced 120 - 130 drops in each minute in steady state in ammonia gas free sector. Preliminary gelation reaction was carried out in ammonia gas sector where drops react with ammonia gas in a bat an eye followed by gelation reaction in column containing ammonia solution 7 M. In ageing process, ADU gels were collected and submerged into a vessel containing ammonia solution which was shaken for 1 hour in a shaker device. Isopropyl alcohol (90% solution was used to wash ADU gels and a digital camera was used to measured spherical form of ADU gels. Diameters in spherical spheroid form were found between 1.8 mm until 2.2 mm. The spherical purity of ADU gels were 10% - 20% others were oblate, prolate spheroid and microsphere which have hugetiny of dimples on the surface.   PRODUKSI GEL ADU SKALA LABORATORIUM DENGAN MENGGUNAKAN GELASI EKSTERNAL UNTUK BAHAN BAKAR ANTARA HTGR. Penelitian ini bertujuan untuk membuat ribuan gel bulat ADU (Ammonium

  1. Lithium iron silicate sol–gel synthesis and electrochemical investigation

    Energy Technology Data Exchange (ETDEWEB)

    Oghbaei, Morteza; Baniasadi, Fazel; Asgari, Sirous, E-mail: sirousasgari@gmail.com

    2016-07-05

    Li{sub 2}FeSiO{sub 4} was synthesized through Sol–Gel method and the effect of calcination temperature, time and chelating agent concentration were investigated. Appropriate calcination temperature above 550 °C was determined by TG/DTA analysis. Afterward, the dried gel powder was calcined at each temperature of 650 °C, 700 °C and 750 °C for 1, 2 and 3 h. XRD studies illustrated the most appropriate calcination temperature of 700 °C for 1 h. To compare the effect of chelating agent concentration, citric acid with molar ratio of 1/3, 2/3 and 1 were used which 1/3 was determined as the best concentration. FE-SEM observation showed that mean grain is size lower than 100 nm. By using this material, a three electrodes test cell was assembled and its electrochemical properties were investigated. The results showed high charge capacity which could be achieved at current density of 0.05 C. - Highlights: • Sol–Gel synthesis of Li{sub 2}FeSiO{sub 4} with tetraethyl orthosilicate, lithium acetate, and iron nitrate. • The most appropriate temperature and time for calcinations were 700 °C and 1 h, respectively. • Maximum charge capacity of 175 mAh/g in Charge–discharge tests for the battery with Li{sub 2}FeSiO{sub 4} cathode. • Charge–discharge current density of C/20 for the synthesized material.

  2. Normoxic polymer gel - basic characterisation and clinical use

    International Nuclear Information System (INIS)

    Scheib, S G; Vogelsanger, W; Gianolini, S; Crescenti, R

    2004-01-01

    The formulation for a new polymer gel, which is made under normal atmospheric conditions, has been published. Because manufacturing and processing can be performed under normal atmospheric conditions, the gel is also called normoxic. Only a few accessories for gel production are necessary, facilitating the use of this gel, which can be easily produced in a clinical environment. The purpose of this study, which is work in progress, was to produce several gel batches with varying concentrations of their compounds, to measure dose response curves, to investigate ageing effects and to use this polymer gel in 3D absolute dose verifications in radiosurgery, IMRT and proton therapy

  3. Multiple-phase behavior and memory effect of polymer gel

    CERN Document Server

    Annaka, M; Nakahira, T; Sugiyama, M; Hara, K; Matsuura, T

    2002-01-01

    A poly(4-acrylamidosalicylic acid) gel (PASA gel) exhibits multiple phases as characterized by distinct degrees of swelling; the gel can take one of four different swelling values, but none of the intermediate values. The gel has remarkable memory: the phase behavior of the gel depends on whether the gel has experienced the most swollen phase or the most collapsed phase in the immediate past. The information is stored and reversibly erased in the form of a macroscopic phase transition behavior. The structure factors corresponding to these four phases were obtained by SANS, which indicated the presence of characteristic structures depending on pH and temperature, particularly in the shrunken state. (orig.)

  4. Protein electrophoretic migration data from custom and commercial gradient gels

    Directory of Open Access Journals (Sweden)

    Andrew J. Miller

    2016-12-01

    Full Text Available This paper presents data related to the article “A method for easily customizable gradient gel electrophoresis” (A.J. Miller, B. Roman, E.M. Norstrom, 2016 [1]. Data is presented on the rate of electrophoretic migration of proteins in both hand-poured and commercially acquired acrylamide gradient gels. For each gel, migration of 9 polypeptides of various masses was measured upon completion of gel electrophoresis. Data are presented on the migration of proteins within separate lanes of the same gel as well as migration rates from multiple gels.

  5. The mechanism and properties of acid-coagulated milk gels

    Directory of Open Access Journals (Sweden)

    Chanokphat Phadungath

    2005-03-01

    Full Text Available Acid-coagulated milk products such as fresh acid-coagulated cheese varieties and yogurt areimportant dairy food products. However, little is known regarding the mechanisms involved in gel formation, physical properties of acid gels, and the effects of processing variables such as heat treatment and gelation temperature on the important physical properties of acid milk gels. This paper reviews the modern concepts of possible mechanisms involved in the formation of particle milk gel aggregation, along with recent developments including the use of techniques such as dynamic low amplitude oscillatory rheology to observe the gel formation process, and confocal laser scanning microscopy to monitor gel microstructure.

  6. SAXS study of silica sols, gels and glasses obtained by the sol gel process

    International Nuclear Information System (INIS)

    Santos, D.I. dos; Aegerter, M.A.

    1988-01-01

    Systematic SAXS studies have been performed at the LURE Synchrotron, Orsay, using an intense beam of point like cross-section to obtain information about the sol -> humid gel -> dried gel -> silica glass transformation. The intensity curves have been analysed in term of power law in log-log plots, whose exponent is related to mass and surface fractal dimensions of the structure. It was found that almost all phases present fractal structures and for the case of basic gels, is of hierarchical nature. The aerogels are formed by a dense matrix, with a smooth surface and exhibit a very narrow auto-similarity range that gives a mass fractal dimension. (author) [pt

  7. Prevalence of Brucella spp in humans

    Directory of Open Access Journals (Sweden)

    Catharina de Paula Oliveira Cavalcanti Soares

    2015-10-01

    Full Text Available Objective: to determine the seroprevalence of Brucella spp in humans.Method: this is an observational study, developed with 455 individuals between 18 and 64 years old, who use the Estratégia de Saúde da Família (Brazil's family health strategy. The serum samples of volunteers underwent buffered acid antigen tests, such as screening, agar gel immunodiffusion and slow seroagglutination test in tubes and 2-Mercaptoethanol.Results: among the samples, 1.98% has responded to buffered-acid antigen, 2.85% to agar gel immunodiffusion test and 1.54% to the slow seroagglutination tests on tubes/2-Mercaptoethanol. The prevalence of Brucella spp was 4.4%, represented by the last two tests.Conclusion: the results of this research suggest that the studied population is exposed to Brucella spp infection.

  8. Gel bead composition for metal adsorption

    Science.gov (United States)

    Scott, Charles D.; Woodward, Charlene A.; Byers, Charles H.

    1990-01-01

    The invention is a gel bead comprising propylene glycol alginate and bone gelatin and is capable of removing metals such as Sr and Cs from solution without adding other adsorbents. The invention could have application to the nuclear industry's waste removal activities.

  9. Gel phase in hydrated calcium dipicolinate

    Science.gov (United States)

    Rajak, Pankaj; Mishra, Ankit; Sheng, Chunyang; Tiwari, Subodh; Krishnamoorthy, Aravind; Kalia, Rajiv K.; Nakano, Aiichiro; Vashishta, Priya

    2017-11-01

    The mineralization of dipicolinic acid (DPA) molecules in bacterial spore cores with Ca2+ ions to form Ca-DPA is critical to the wet-heat resistance of spores. This resistance to "wet-heat" also depends on the physical properties of water and DPA in the hydrated Ca-DPA-rich protoplasm. Using reactive molecular dynamics simulations, we have determined the phase diagram of hydrated Ca-DPA as a function of temperature and water concentration, which shows the existence of a gel phase along with distinct solid-gel and gel-liquid phase transitions. Simulations reveal monotonically decreasing solid-gel-liquid transition temperatures with increasing hydration, which explains the experimental trend of wet-heat resistance of bacterial spores. Our observation of different phases of water also reconciles previous conflicting experimental findings on the state of water in bacterial spores. Further comparison with an unmineralized hydrated DPA system allows us to quantify the importance of Ca mineralization in decreasing diffusivity and increasing the heat resistance of the spore.

  10. Simple Cloud Chambers Using Gel Ice Packs

    Science.gov (United States)

    Kamata, Masahiro; Kubota, Miki

    2012-01-01

    Although cloud chambers are highly regarded as teaching aids for radiation education, school teachers have difficulty in using cloud chambers because they have to prepare dry ice or liquid nitrogen before the experiment. We developed a very simple and inexpensive cloud chamber that uses the contents of gel ice packs which can substitute for dry…

  11. 21 CFR 520.1452 - Moxidectin gel.

    Science.gov (United States)

    2010-04-01

    ...) Limitations. For oral use in horses and ponies 6 months of age and older. Not for use in horses and ponies... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1452 Moxidectin gel. (a...

  12. The Sol-Gel-Xerogel Transition

    Science.gov (United States)

    1993-11-01

    relative mobili- ty are supported by the ESR (Electron Spin Resonance) studies of * * * Ikoma et al. [301 demonstrating that polyamine copper(II) chelates...deactivation of the triplet state of the molecule in the case of RTP. Recent studies on the photoisomerization of azobenzene in sol-gel glass films by

  13. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS ...

    African Journals Online (AJOL)

    Four strains of eri, Samia cynthia ricini Lepidoptera: Saturniidae that can be identified morphologically and maintained at North East Institute of Science and Technology, Jorhat were characterized based on their protein profile by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and DNA by random ...

  14. Preparing size markers for gel electrophoresis.

    Science.gov (United States)

    Nilsen, Timothy W

    2013-12-01

    Here we present two simple methods for preparing radiolabeled size markers for gel electrophoresis. The first procedure describes the generation of an RNA marker ladder by the alkaline hydrolysis of (32)P 5'- or 3'-end-labeled RNA. The second procedure describes the labeling of DNA fragments produced by digestion of pBR322 with the restriction enzyme MspI.

  15. Denaturing urea polyacrylamide gel electrophoresis (Urea PAGE).

    Science.gov (United States)

    Summer, Heike; Grämer, René; Dröge, Peter

    2009-10-29

    Urea PAGE or denaturing urea polyacrylamide gel electrophoresis employs 6-8 M urea, which denatures secondary DNA or RNA structures and is used for their separation in a polyacrylamide gel matrix based on the molecular weight. Fragments between 2 to 500 bases, with length differences as small as a single nucleotide, can be separated using this method(1). The migration of the sample is dependent on the chosen acrylamide concentration. A higher percentage of polyacrylamide resolves lower molecular weight fragments. The combination of urea and temperatures of 45-55 degrees C during the gel run allows for the separation of unstructured DNA or RNA molecules. In general this method is required to analyze or purify single stranded DNA or RNA fragments, such as synthesized or labeled oligonucleotides or products from enzymatic cleavage reactions. In this video article we show how to prepare and run the denaturing urea polyacrylamide gels. Technical tips are included, in addition to the original protocol (1,2).

  16. Polyacrylamide gel polymerization with adjustable gelation rate

    Czech Academy of Sciences Publication Activity Database

    Wiesner, Ivo; Wiesnerová, Dana

    2002-01-01

    Roč. 32, - (2002), s. 740-742 ISSN 0736-6205 R&D Projects: GA AV ČR KSK5052113; GA ČR GA521/00/0075 Keywords : polyacrylamide gel Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.173, year: 2002

  17. Thermal Decomposition Characteristics of ADU Gel Spheres

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Kyung Chai; Eom, Sung Ho; Kim, Yeon Ku; Kim, Young Min; Kim, Woong Ki; Kim, Bong Ku; Lee, Young Woo; Cho, Moon Seoung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    HTGR nuclear fuel uses a modified sol.gel GSP (Gel Supported Precipitation) method, which is a wet method used in most countries. ADU(Ammonium DiUranate) gel particles fabricated in this way pass through thermal treatments and become final UO{sub 2} microspheres. The washing characteristics such as washing volume, duration, and times during AWD(ageing, washing and drying) process after the spherical ADU gel particles preparation by the GSP method was studied. The VHTR (Very High Temperature Gas Reactor) is one of the reactor concepts in the Gen IV International Collaboration. Unlike light water reactor currently in use in Korea, a HTGR actually functions as a gas cooled reactor where the high temperature heat generated from nuclear fission in a reactor is cooled by He gas, with uranium dioxide (UO{sub 2} is globally used) used as fuel for the nuclear fission. Generally, nuclear fuel used in a HTGR is fabricated into a TRISO (TRi.ISOtropic) structure that can prevent the leakage of nuclear fission products at high temperatures.

  18. Two-dimensional gel isoelectric focusing

    Czech Academy of Sciences Publication Activity Database

    Šťastná, Miroslava; Šlais, Karel

    2005-01-01

    Roč. 26, č. 18 (2005), s. 3586-3591 ISSN 0173-0835 R&D Projects: GA AV ČR IAA4031302; GA AV ČR IBS4031201 Institutional research plan: CEZ:AV0Z40310501 Keywords : gel isoelectric focusing * pI markers * proteins Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.850, year: 2005

  19. Gels and microgels for nanotechnological applications.

    Science.gov (United States)

    Fernández-Barbero, Antonio; Suárez, Iván J; Sierra-Martín, B; Fernández-Nieves, A; de Las Nieves, F Javier; Marquez, Manuel; Rubio-Retama, J; López-Cabarcos, Enrique

    2009-01-01

    In recent years, "smart" materials have been the focus of considerable interest, from both fundamental and applied perspectives. Polymer gels are within this category; they respond to specific environmental stimuli by changing their size. Thus, the internal structure, the refractive index, and the mechanical properties of the polymer network change. They are considered super absorbent materials, as they can absorb solvent up to several hundred times their own weight. They respond rapidly to local environmental variations, an important fact in device miniaturization and microsensor developments. As size changes are accompanied by changes in internal dimensions, microgels have found application as carriers of therapeutic drugs and as diagnostic agents. They have also been used as microreactors, optically active materials, for template synthesis of nanoparticles or fabrication of artificial muscle. In this paper we review a set of application based on the special features associated to this systems. Basic concepts on the physical-chemistry of gel swelling is first described, followed by different applications covering drug delivery, composite materials using polymer gels to modulate optical or magnetic and electrical properties, molecular imprinting, gel-based biosensors and polymer sensors and actuators used in the field of artificial muscles.

  20. Sol-Gel Derived Hafnia Coatings

    Science.gov (United States)

    Feldman, Jay D.; Stackpoole, Mairead; Blum, Yigal; Sacks, Michael; Ellerby, Don; Johnson, Sylvia M.; Venkatapathy, Ethiras (Technical Monitor)

    2002-01-01

    Sol-gel derived hafnia coatings are being developed to provide an oxidation protection layer on ultra-high temperature ceramics for potential use in turbine engines (ultra-efficient engine technology being developed by NASA). Coatings using hafnia sol hafnia filler particles will be discussed along with sol synthesis and characterization.

  1. Formulation of Bioadhesive Carbomer Gel Incorporating Drug ...

    African Journals Online (AJOL)

    Purpose: To formulate carbomer gel to localize and target drug action in periodontal pockets. Methods: Diclofenac sodium (DS, anti-inflammatory) and metronidazole hydrochloride (MH, antibacterial) were loaded in gelatin microspheres using glutaraldehyde cross-linking. The microspheres were evaluated for drug loading, ...

  2. Sol–gel processing of carbidic glasses

    Indian Academy of Sciences (India)

    Unknown

    The endothermic peak and weight loss below. 200°C are associated with condensation reactions and evaporation of reaction products and residual water. The extent of these have been found to be lower than those for pure silica gels. The weight loss after 400°C is assigned to condensation of silanol groups and formation ...

  3. Fluorescence metrology of silica sol-gels

    Indian Academy of Sciences (India)

    We have developed a new method for measuring in-situ the growth of the nanometre-size silica particles which lead to the formation of sol-gel glasses. This technique is based on the decay of fluorescence polarisation anisotropy due to Brownian rotation of dye molecules bound to the particles. Results to date give near ...

  4. Synthesis and Characterization of Cellulose-Based Hydrogels to Be Used as Gel Electrolytes

    Directory of Open Access Journals (Sweden)

    Maria Assunta Navarra

    2015-11-01

    Full Text Available Cellulose-based hydrogels, obtained by tuned, low-cost synthetic routes, are proposed as convenient gel electrolyte membranes. Hydrogels have been prepared from different types of cellulose by optimized solubilization and crosslinking steps. The obtained gel membranes have been characterized by infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and mechanical tests in order to investigate the crosslinking occurrence and modifications of cellulose resulting from the synthetic process, morphology of the hydrogels, their thermal stability, and viscoelastic-extensional properties, respectively. Hydrogels liquid uptake capability and ionic conductivity, derived from absorption of aqueous electrolytic solutions, have been evaluated, to assess the successful applicability of the proposed membranes as gel electrolytes for electrochemical devices. To this purpose, the redox behavior of electroactive species entrapped into the hydrogels has been investigated by cyclic voltammetry tests, revealing very high reversibility and ion diffusivity.

  5. (3-Mercaptopropyl)trimethoxysilane-derived Porous Gel Monolith via Thioacetal Reaction-Assisted Sol-Gel Route

    Energy Technology Data Exchange (ETDEWEB)

    Ito, S; Nishi, M; Kurahashi, T; Matsubara, S; Shimotsuma, Y; Miura, K; Hirao, K [Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-Daigaku-Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan); Kanamori, K; Nakanishi, K, E-mail: west@collon1.kuic.kyoto-u.ac.jp [Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan)

    2011-10-29

    Porous gel monolith was synthesized by reacting (3-mercaptopropyl)trimethoxysilane (MPTMS) with acetone on acidic conditions. It is known that MPTMS itself is difficult to turn into gel on acidic conditions and instead oligomers are obtained owing to the large mercaptopropyl group. In our system, the gels were obtained since acetone worked as a cross-linker via thioacetal reaction. Additionally, Au ions were selectively adsorbed on the obtained gel. When an obtained white gel was soaked in a chloroauric acid solution, the gel turned brown and was getting dark depending on the soaked time; on the other hand, the color of the solution turned from yellow to colorless.

  6. Formulation and in vitro and in vivo evaluation of a new osteoprotegerin-chitosan gel for bone tissue regeneration.

    Science.gov (United States)

    Jayash, Soher Nagi; Hashim, Najihah Mohd; Misran, Misni; Baharuddin, N A

    2017-02-01

    The osteoprotegerin (OPG) system plays a critical role in bone remodelling by regulating osteoclast formation and activity. The study aimed to determine the physicochemical properties and biocompatibility of a newly formulated OPG-chitosan gel. The OPG-chitosan gel was formulated using human OPG protein and water-soluble chitosan. The physicochemical properties were determined using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Gel morphology was determined using scanning electron microscopy (SEM) and then it was subjected to a protein release assay and biodegradability test. An in vitro cytotoxicity test on normal human periodontal ligament (NHPL) fibroblasts and normal human (NH) osteoblasts was carried out using the AlamarBlue assay. In vivo evaluation in a rabbit model involved creating critical-sized defects in calvarial bone, filling with the OPG-chitosan gel and sacrificing at 12 weeks. In vitro results demonstrated that the 25 kDa OPG-chitosan gel had the highest rate of protein release and achieved 90% degradation in 28 days. At 12 weeks, the defects filled with 25 kDa OPG-chitosan gel showed significant (p < 0.05) new bone formation and the highest expression of osteocalcin and osteopontin compared to controls. Thus, the 25 kDa OPG-chitosan gel could be a promising new biomaterial for tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 398-407, 2017. © 2016 Wiley Periodicals, Inc.

  7. [Azelaic acid 15% gel in the treatment of acne vulgaris. Combined results of two double-blind clinical comparative studies].

    Science.gov (United States)

    Gollnick, Harald P M; Graupe, Klaus; Zaumseil, Rolf-Peter

    2004-10-01

    Topical measures are still the mainstay in the therapy of mild-to-moderate acne vulgaris. Azelaic acid 20% in a cream formulation has been established as an efficacious and safe topical drug for 15 years. A new non-alcoholic hydrogel formulation containing 15% azelaic acid was clinically tested against two standard drugs--5% benzoyl peroxide (BPO) and 1% clindamycin. In two independent, randomized, blinded comparative trials 15% azelaic acid gel was clinically tested against 5% benzoyl peroxide (BPO) gel in 351 patients and against 1% clindamycin gel in 229 patients. The drugs were applied b.i.d. for 4 months. Azelaic acid 15% gel proved to be as effective as BPO and clindamycin with median % reduction of the inflamed lesion (papules and pustules) of 70%, and 71% respectively. The azelaic acid gel was well-tolerated, the side effects (local burning and irritation) were distinctly less than with BPO but more pronounced than with clindamycin. Despite these side effects, the treatment was well-accepted by the majority of patients. Azelaic acid gel is an effective topical monotherapy for mild-to-moderate acne vulgaris; its new gel form is an enrichment of acne therapy.

  8. Ultraviolet absorption detection of DNA in gels

    International Nuclear Information System (INIS)

    Mahon, A.R.

    1998-01-01

    A method and apparatus for the detection and quantification of large fragments of unlabelled deoxyribonucleic acid (DNA) in agarose gels is presented. The technique is based on ultra-violet (UV) absorption by nucleotides. A deuterium lamp was used to illuminate regions of an electrophoresis gel. As DNA bands passed through the illuminated region of the gel the amount of UV light transmitted was reduced due to DNA absorption. Two detection systems were investigated. In the first system, synthetic chemical vapour deposition (CVD) diamond strip detectors were used to locate regions of DNA in the gels by detecting the transmitted light. CVD diamond has a high indirect band gap of 5.45 eV and is therefore sensitive to UV photons of wavelengths < 224 nm. A number of CVD diamond samples were characterised to investigate their suitability as detectors for this application. The detectors' quantum efficiency, UV response and time response were measured. DNA bands containing as little as 20 ng were detected by the diamond. In a second system, a deuterium lamp was used to illuminate individual sample lanes of an electrophoresis gel via an array of optical fibres. During electrophoresis the regions of DNA were detected with illumination at 260 nm, using a UV-sensitive charge coupled device (CCD). As the absorption coefficient of a DNA sample is approximately proportional to its mass, the technique is inherently quantitative. This system had a detection limit of 0.25 ng compared with 2-10 ng for the most popular conventional technique, ethidium bromide (EtBr) staining. Using this detection technique, the DNA sample remains in its native state. The removal of carcinogenic dyes from the detection procedure greatly reduces associated biological hazards. (author)

  9. Construction of chitin/PVA composite hydrogels with jellyfish gel-like structure and their biocompatibility.

    Science.gov (United States)

    He, Meng; Wang, Zhenggang; Cao, Yan; Zhao, Yanteng; Duan, Bo; Chen, Yun; Xu, Min; Zhang, Lina

    2014-09-08

    High strength chitin/poly(vinyl alcohol) (PVA) composite hydrogels (RCP) were constructed by adding PVA into chitin dissolved in a NaOH/urea aqueous solution, and then by cross-linking with epichlorohydrin (ECH) and freezing-thawing process. The RCP hydrogels were characterized by field emission scanning electron microscopy, FTIR, differential scanning calorimetry, solid-state (13)C NMR, wide-angle X-ray diffraction, and compressive test. The results revealed that the repeated freezing/thawing cycles induced the bicrosslinked networks consisted of chitin and PVA crystals in the composite gels. Interestingly, a jellyfish gel-like structure occurred in the RCP75 gel with 25 wt % PVA content in which the amorphous and crystalline PVA were immobilized tightly in the chitin matrix through hydrogen bonding interaction. The freezing/thawing cycles played an important role in the formation of the layered porous PVA networks and the tight combining of PVA with the pore wall of chitin. The mechanical properties of RCP75 were much higher than the other RCP gels, and the compressive strength was 20× higher than that of pure chitin gels, as a result of broadly dispersing stress caused by the orderly multilayered networks. Furthermore, the cell culture tests indicated that the chitin/PVA composite hydrogels exhibited excellent biocompatibility and safety, showing potential applications in the field of tissue engineering.

  10. A SEM evaluation of a 6% hydrogen peroxide tooth whitening gel on dental materials in vitro.

    Science.gov (United States)

    Schemehorn, Bruce; González-Cabezas, Carlos; Joiner, Andrew

    2004-01-01

    The aim of this study was to evaluate the effects of a novel 6% hydrogen peroxide gel on the surface morphology of dental gold, amalgam, porcelain and composite. Admixed high-copper amalgam and hybrid resin composite specimens were prepared in extracted teeth using standard clinical procedures. Feldspathic porcelain and type III gold specimens were prepared in a mould using standard laboratory procedures. One half of the specimens were covered with nail varnish to serve as the control side, leaving the other half exposed. The specimens were treated with pooled whole saliva (1 h), followed by the peroxide gel (20 min), rinsing with water and returning to saliva. This cycling protocol was continued until a total of 28 treatments with the peroxide gel were completed. The samples were prepared for SEM. There were no observable differences at 200x and 2000x magnifications between the control and peroxide gel treated sides on any of the materials tested. There were no significant effects of the 6% hydrogen peroxide gel on the surface morphology of any of the dental materials tested.

  11. Textural behavior of gels formed by rice starch and whey protein isolate: Concentration and crosshead velocities

    Directory of Open Access Journals (Sweden)

    Thiago Novaes Silva

    Full Text Available ABSTRACT Fabricated food gels involving the use of hydrocolloids are gaining polpularity as confectionery/convenience foods. Starch is commonly combined with a hydrocolloid (protein our polyssacharides, particularly in the food industry, since native starches generally do not have ideal properties for the preparation of food products. Therefore the texture studies of starch-protein mixtures could provide a new approach in producing starch-based food products, being thus acritical attribute that needs to be carefully adjusted to the consumer liking. This work investigated the texture and rheological properties of mixed gels of different concentrations of rice starch (15%, 17.5%, and 20% and whey protein isolate (0%, 3%, and 6% with different crosshead velocities (0.05, 5.0, and 10.0 mm/s using a Box-Behnken experimental design. The samples were submitted to uniaxial compression tests with 80% deformation in order to determinate the following rheological parameters: Young’s modulus, fracture stress, fracture deformation, recoverable energy, and apparent biaxial elongational viscosity. Gels with a higher rice starch concentration that were submitted to higher test velocities were more rigid and resistant, while the whey protein isolate concentration had little influence on these properties. The gels showed a higher recoverable energy when the crosshead velocity was higher, and the apparent biaxial elongational viscosity was also influenced by this factor. Therefore, mixed gels exhibit different properties depending on the rice starch concentration and crosshead velocity.

  12. The relationship between mechanical properties and ballistic penetration depth in a viscoelastic gel.

    Science.gov (United States)

    Mrozek, Randy A; Leighliter, Brad; Gold, Christopher S; Beringer, Ian R; Yu, Jian H; VanLandingham, Mark R; Moy, Paul; Foster, Mark H; Lenhart, Joseph L

    2015-04-01

    The fundamental material response of a viscoelastic material when impacted by a ballistic projectile has important implication for the defense, law enforcement, and medical communities particularly for the evaluation of protective systems. In this paper, we systematically vary the modulus and toughness of a synthetic polymer gel to determine their respective influence on the velocity-dependent penetration of a spherical projectile. The polymer gels were characterized using tensile, compression, and rheological testing taking special care to address the unique challenges associated with obtaining high fidelity mechanical data on highly conformal materials. The depth of penetration data was accurately described using the elastic Froude number for viscoelastic gels ranging in Young's modulus from ~60 to 630 kPa. The minimum velocity of penetration was determined to scale with the gel toughness divided by the gel modulus, a qualitative estimate for the zone of deformation size scale upon impact. We anticipate that this work will provide insight into the critical material factors that control ballistic penetration behavior in soft materials and aid in the design and development of new ballistic testing media. Published by Elsevier Ltd.

  13. Study of silica sol-gel materials for sensor development

    Science.gov (United States)

    Lei, Qiong

    Silica sol-gel is a transparent, highly porous silicon oxide glass made at room temperature by sol-gel process. The name of silica sol-gel comes from the observable physical phase transition from liquid sol to solid gel during its preparation. Silica sol-gel is chemically inert, thermally stable, and photostable, it can be fabricated into different desired shapes during or after gelation, and its porous structure allows encapsulation of guest molecules either before or after gelation while still retaining their functions and sensitivities to surrounding environments. All those distinctive features make silica sol-gel ideal for sensor development. Study of guest-host interactions in silica sol-gel is important for silica-based sensor development, because it helps to tailor local environments inside sol-gel matrix so that higher guest loading, longer shelf-life, higher sensitivity and faster response of silica gel based sensors could be achieved. We focused on pore surface modification of two different types of silica sol-gel by post-grafting method, and construction of stable silica hydrogel-like thin films for sensor development. By monitoring the mobility and photostability of rhodamine 6G (R6G) molecules in silica alcogel thin films through single molecule spectroscopy (SMS), the guest-host interactions altered by post-synthesis grafting were examined. While physical confinement remains the major factor that controls mobility in modified alcogels, both R6G mobility and photostability register discernable changes after surface charges are respectively reversed and neutralized by aminopropyltriethoxysilane (APTS) and methyltriethoxysilane (MTES) grafting. The change in R6G photostability was found to be more sensitive to surface grafting than that of mobility. In addition, silica film modification by 0.4% APTS is as efficient as that by pure MTES in lowering R6G photostability, which suggests that surface charge reversal is more effective than charge neutralization

  14. Sol-Gel Synthesis of Au-Nanoparticle Dispersed Bicontinuous Macroporous Siloxane Gel

    Energy Technology Data Exchange (ETDEWEB)

    Hamada, Y; Nishi, M; Shimotsuma, Y; Miura, K; Hirao, K, E-mail: west@collon1.kuic.kyoto-u.ac.jp [Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510 (Japan)

    2011-10-29

    We synthesized Au-nanoparticle dispersed siloxane gel with well-defined bicontinuous macroporous morphologies. We employed methyltrimethoxysilane (MTMS) as a precursor of the gel skeleton, and also employed hydrogen tetrachloroaurate(III) as both a precursor of Au nanoparticles and an acid catalyst for hydrolysis/condensation of methoxysilanes. The effect of adding (3-mercaptopropyl)trimethoxysilane (MPTMS) as a starting material on the obtained structure was also investigated. It is found that Au nanoparticles of 20-30 nm in grain size are uniformly dispersed on the gel surface in the system containing MPTMS; in contrast, Au nanoparticles assembled in the pits in the MPTMS-free system. All the heat-treated MPTMS-containing gels showed surface plasmon absorption, and the peaks shifted from 550 to 520 nm with increasing the calcination temperature.

  15. Gel polymer electrolytes based on PMMA III. PMMA gels containing cadmium

    Czech Academy of Sciences Publication Activity Database

    Vondrák, Jiří; Sedlaříková, M.; Velická, Jana; Klápště, Břetislav; Novák, V.; Reiter, Jakub

    2003-01-01

    Roč. 48, č. 8 (2003), s. 1001-1004 ISSN 0013-4686 R&D Projects: GA AV ČR IAA4032002; GA ČR GA104/02/0731; GA MŠk ME 216 Institutional research plan: CEZ:AV0Z4032918; CEZ:MSM 262200010 Keywords : gel polymer electrolytes * polymethylmethacrylate * cadmium gel electrolyte Subject RIV: CA - Inorganic Chemistry Impact factor: 1.996, year: 2003

  16. Species identification of cooked fish by urea isoelectric focusing and sodium dodecylsulfate polyacrylamide gel electrophoresis : a collaborative study

    DEFF Research Database (Denmark)

    Rehbein, H.; Kundiger, R.; Yman, I.M.

    1999-01-01

    The suitability and reliability of urea IEF and SDS-PAGE for the identification of cooked fish flesh was tested by a collaborative study among nine laboratories. Urea IEF was performed with CleanGels as well as with ImmobilineGels, and ExcelGels were used for SDS-PAGE, enabling all three types...... was incorrect, and with SDS-PAGE a similar result was obtained. It was concluded that methods, as now developed, are suitable for checking the species declaration of fishery products. (C) 1999 Elsevier Science Ltd. All rights reserved...

  17. Simplified riboprobe purification using translucent straws as gel tubes.

    Science.gov (United States)

    Kol, S; Ben-Shlomo, I; Adashi, E Y; Rohan, R M

    1996-01-01

    Gel purification of radioactive riboprobes enhances the quality of the ribonuclease protection assay. A simple and effective method for riboprobe purification is described. The method uses acrylamide gels in plastic tubes to achieve electrophoretic separation of the RNA polymerase products.

  18. Accumulation of humic acid in DET/DGT gels

    Digital Repository Service at National Institute of Oceanography (India)

    Van der Veeken, P.L.R.; Chakraborty, P.; Van Leeuwen, H.P.

    in Thin film) that these natural complexing agents do enter the gel layer, and that humic acids even appear to accumulate in the gel, with enrichment factors typicallyonthe order of 10. The results have consequences for the interpretation of DGT...

  19. Study of nuclear glasses alteration gel and synthesis of some model gels

    International Nuclear Information System (INIS)

    Ricol, S.

    1995-01-01

    This work deals with the general problem of alteration of the reference nuclear glass R7T7. Attention is paid particularly to the altered layer formed at the glass surface during alteration process. In opposition to previous works, related essentially to glass dissolution kinetics based on chemical analyses of lixiviated elements, this thesis deals with alteration problems through structural studies of the reference glass and derived gel. This approach allows the determination of mechanisms for the gel formation and a better understanding of the behaviour of glasses towards lixiviation. Both approaches appeared complementary. Based on several spectroscopic techniques, this work showed the particular role of cations such as calcium, zirconium and iron. Studies of silica-based synthetic gels showed the synergic effect of formers cation and of one highly coordinated cation. The variation of the wavenumber related to Si-O-Si asymmetric stretching vibration can be correlated to O/Si ratio for ternary systems Si/Na/Zr. On the contrary, the Si losses of the materials depend on the number of non-bridging oxygen atoms. In the perspective of long-term behaviour, the alteration gel presents better characteristics than initial glass. It is therefore a highly stable material in static conditions. In the same way, synthetic gels are materials with very low solubilities (much lower than the alteration gel) and could be used as confining matrices. (authors). refs., 71 figs., 37 tabs

  20. Automatic DNA Diagnosis for 1D Gel Electrophoresis Images using Bio-image Processing Technique.

    Science.gov (United States)

    Intarapanich, Apichart; Kaewkamnerd, Saowaluck; Shaw, Philip J; Ukosakit, Kittipat; Tragoonrung, Somvong; Tongsima, Sissades

    2015-01-01

    DNA gel electrophoresis is a molecular biology technique for separating different sizes of DNA fragments. Applications of DNA gel electrophoresis include DNA fingerprinting (genetic diagnosis), size estimation of DNA, and DNA separation for Southern blotting. Accurate interpretation of DNA banding patterns from electrophoretic images can be laborious and error prone when a large number of bands are interrogated manually. Although many bio-imaging techniques have been proposed, none of them can fully automate the typing of DNA owing to the complexities of migration patterns typically obtained. We developed an image-processing tool that automatically calls genotypes from DNA gel electrophoresis images. The image processing workflow comprises three main steps: 1) lane segmentation, 2) extraction of DNA bands and 3) band genotyping classification. The tool was originally intended to facilitate large-scale genotyping analysis of sugarcane cultivars. We tested the proposed tool on 10 gel images (433 cultivars) obtained from polyacrylamide gel electrophoresis (PAGE) of PCR amplicons for detecting intron length polymorphisms (ILP) on one locus of the sugarcanes. These gel images demonstrated many challenges in automated lane/band segmentation in image processing including lane distortion, band deformity, high degree of noise in the background, and bands that are very close together (doublets). Using the proposed bio-imaging workflow, lanes and DNA bands contained within are properly segmented, even for adjacent bands with aberrant migration that cannot be separated by conventional techniques. The software, called GELect, automatically performs genotype calling on each lane by comparing with an all-banding reference, which was created by clustering the existing bands into the non-redundant set of reference bands. The automated genotype calling results were verified by independent manual typing by molecular biologists. This work presents an automated genotyping tool from DNA

  1. Automatic DNA Diagnosis for 1D Gel Electrophoresis Images using Bio-image Processing Technique

    Science.gov (United States)

    2015-01-01

    Background DNA gel electrophoresis is a molecular biology technique for separating different sizes of DNA fragments. Applications of DNA gel electrophoresis include DNA fingerprinting (genetic diagnosis), size estimation of DNA, and DNA separation for Southern blotting. Accurate interpretation of DNA banding patterns from electrophoretic images can be laborious and error prone when a large number of bands are interrogated manually. Although many bio-imaging techniques have been proposed, none of them can fully automate the typing of DNA owing to the complexities of migration patterns typically obtained. Results We developed an image-processing tool that automatically calls genotypes from DNA gel electrophoresis images. The image processing workflow comprises three main steps: 1) lane segmentation, 2) extraction of DNA bands and 3) band genotyping classification. The tool was originally intended to facilitate large-scale genotyping analysis of sugarcane cultivars. We tested the proposed tool on 10 gel images (433 cultivars) obtained from polyacrylamide gel electrophoresis (PAGE) of PCR amplicons for detecting intron length polymorphisms (ILP) on one locus of the sugarcanes. These gel images demonstrated many challenges in automated lane/band segmentation in image processing including lane distortion, band deformity, high degree of noise in the background, and bands that are very close together (doublets). Using the proposed bio-imaging workflow, lanes and DNA bands contained within are properly segmented, even for adjacent bands with aberrant migration that cannot be separated by conventional techniques. The software, called GELect, automatically performs genotype calling on each lane by comparing with an all-banding reference, which was created by clustering the existing bands into the non-redundant set of reference bands. The automated genotype calling results were verified by independent manual typing by molecular biologists. Conclusions This work presents an

  2. A comparison of the efficacy of metronidazole vaginal gel and Myrtus (Myrtus communis extract combination and metronidazole vaginal gel alone in the treatment of recurrent bacterial vaginosis

    Directory of Open Access Journals (Sweden)

    Mansoure Masoudi

    2017-02-01

    Full Text Available Objective: Due to the high incidence of bacterial vaginosis (BV and its resistance to chemical medications and considering the anti-bacterial and anti-fungal effects of Myrtus communis, the present study aimed to compare the therapeutic effects of the vaginal gel of M. communis 2% (in metronidazole base with metronidazole vaginal gel 0.75% alone on BV.Materials and Methods: This research was a random­ized controlled clinical trial conducted on 80 women of 18-40 years old with BV. Patients were divided into two groups of 40 women. Diagnostic criteria were Amsel's criteria and Gram staining. The first group received vaginal gel of metronidazole plus M. communis 2% and the second group received metronidazole vaginal gel alone for five consecutive nights. Therapeutic effects and Amsel’s criteria were assessed after one week. Finally, the data were analyzed by SPSS 16 using t-test and Chi square tests.Results: There was a significant difference in the therapeutic response between the two groups. The results demonstrated that the combination of metronidazole and M. communis had a higher efficiency (p

  3. Polymer gel dosimetry system for radiation therapy

    International Nuclear Information System (INIS)

    Maryanski, M.J.; Schulz, R.J.; Gignac, C.; Eastman, P.; Gore, J.C.

    1995-01-01

    Purpose/Objective: Recently developed treatment modalities such as stereotactic and conformal radiation therapy produce complex dose distributions which are difficult or impractical to measure with conventional dosimetry instrumentation. Three-dimensional treatment planning systems which purport to calculate these complex dose distributions should be compared to experimental results before being routinely applied to clinical problems. There is a need for a new class of tissue-equivalent dosimeters capable of providing accurate, high resolution, time-integrated and three dimensional dose distributions. The recently developed BANG polymer gel dosimetry system (MGS Research, Inc., Guilford, CT) is ideally suited for the task described above. Physico-chemical principles of the polymer gel dosimetry are presented, together with examples of its application to radiation therapy. Data analysis and display program, written for Macintosh computer, is demonstrated. Materials and Methods: Radiation-induced polymerization of acrylic monomers, which are dispersed in tissue-equivalent gelatin, has been shown to be dependent on the dose, but independent of the dose rate or photon energy. Therefore, the spatial distribution of polymer in the gel is precisely representative of the dose distribution. As the polymeric microparticles reduce the water proton NMR relaxation times in the gel, the dose distribution can be measured with high resolution and accuracy using magnetic resonance imaging. Also, as these microparticles cannot diffuse through the gelatin matrix, their distribution is permanent. An improved formulation of the BANG dosimeter consists of 3% w/v acrylic acid, 3% N,N'-methylene-bis-acrylamide, 1% sodium hydroxide, 5% gelatin, and 88% water. MR images are transferred via a local network to a Macintosh computer, and R2 maps constructed on the basis of multiple TE images, using a non-linear least squares fit based on the Levenberg-Marquardt algorithm. A dose-to-R2

  4. Prenatal Virilization Associated with Paternal Testosterone Gel Therapy

    OpenAIRE

    Patel, Anisha; Rivkees, Scott A.

    2010-01-01

    Transdermal testosterone gels are used in the treatment of hypoandrogenism of males. Virilization due to exposure to testosterone gels has been reported in children resulting in a US Food and Drug Administration (FDA) warning about secondary exposure to these products. At present, we are unaware of prenatal virilization associated with unintentional testosterone gel exposure. We report prenatal virilization in a female infant due to secondary maternal exposure to the father's testosterone gel...

  5. Development and dosimetric evaluation of radiochromic PCDA vesicle gel dosimeters

    International Nuclear Information System (INIS)

    Sun, P.; Fu, Y.C.; Hu, J.; Hao, N.; Huang, W.; Jiang, B.

    2016-01-01

    The gel dosimeter has the unique capacity in recording radiation dose distribution in three dimensions (3D), which has the specific advantages in dosimetry measurements where steep dose gradients exist, such as in intensity-modulated radiation therapy (IMRT), brachytherapy and so on. Some 3D dosimeters, such as Fricke gel dosimeters, polymer gel dosimeters, the PRESAGE plastic dosimeters and micelle gel dosimeters have appeared recently. However, there are several disadvantages of these 3D dosimeters limit their application in radiotherapy dose verification. In this study, a novel radiochromic gel dosimeter for 3D dose verification of radiotherapy was developed by dispersing nanovesicles self-assembled by 10,12-pentacosadiynoic acid (PCDA) into the tissue equivalence gel matrix. The characteristics of radiochromic PCDA vesicle gel dosimeters were evaluated. The results indicate that these radiochromic gel dosimeters have good linear dose response to X-ray irradiation in the dose range of 2–100 Gy. In addition, the radiochromic gel dosimeters breakthrough the limitations of the existing gel dosimeters such as diffusion effect, post-radiation effect, and poor forming ability. The response of the gel dosimeter does not show any dose rate dependence, energy dependence and temperature effect, and there was no obvious difference in the gel response between single and cumulative dose of fractional irradiation. Hence, the radiochromic PCDA vesicle gel dosimeters developed in this study could be generally applied to 3D dose verification in radiotherapy. - Highlights: • A novel radiochromic gel dosimeter was developed by dispersing PCDA nanovesicles into the tissue equivalence gel matrix. • This nanovesicle overcomes the dose image blurring caused by the diffusion of monomer molecules. • This nanovesicle limits the polymer chain growth, so as to reduce the post-radiation effect. • The gel matrixes possess excellent tissue equivalence and elastic strength, which

  6. Viscoelastic nature of Au nanoparticle–PDMS nanocomposite gels

    Indian Academy of Sciences (India)

    Even a very low Au content of 0.09 wt% is sufficient enough to bring in the transition from sponge state to gel state at room temperature. ... gel properties can have direct influence on the processability of Au nanoparticle–PDMS nanocomposite gels, with interesting implications in electronic, optical and microfluidic devices.

  7. 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.

  8. Power Law Behavior of Structural Properties of Protein Gels

    NARCIS (Netherlands)

    Verheul, Marleen; Roefs, Sebastianus P.F.M.; Mellema, J.; Kruif, Kees G.

    1998-01-01

    Whey proteins are globular, heat-sensitive proteins. The gel structure, the formation of this structure, and the rheological properties of particulate whey protein isolate (WPI) gels have been investigated. On increasing the NaCl concentration, the permeability of the WPI gels increased, indicating

  9. Outdoor weathering of sol-gel-treated wood

    Science.gov (United States)

    Mandla A Tshabalala; Ryan Libert; Nancy Ross Sutherland

    2009-01-01

    Outdoor weathering of wood specimens treated with sol-gel formulations based on methyltrimethoxysilane (MTMOS), hexadecyltrimethoxysilane (HDTMOS), and ferric-zirconia-titania (Fe-Zr-Ti) sol was evaluated. The sol-gel process allowed deposition of a thin film of hybrid inorganic-organic networks (gel) in the wood cell wall that resulted in improved outdoor weathering...

  10. Agarose Gel Size Selection for DNA Sequencing Libraries.

    Science.gov (United States)

    Mardis, Elaine; McCombie, W Richard

    2017-08-01

    Agarose gel electrophoresis may be used to purify fragmented genomic DNA after ligation of adaptors. After electrophoresis, the region of the gel containing the desired size range of DNA is excised, and the DNA is subsequently extracted from the gel and purified by passage through a spin column. © 2017 Cold Spring Harbor Laboratory Press.

  11. 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.

  12. Effect of 5% benzocaine gel on relieving pain caused by fixed orthodontic appliance activation. A double-blind randomized controlled trial.

    Science.gov (United States)

    Eslamian, L; Gholami, H; Mortazavi, S A R; Soheilifar, S

    2016-11-01

    To compare the effectiveness of 5% benzocaine gel and placebo gel on reducing pain caused by fixed orthodontic appliance activation. Thirty subjects (15-25 years) undergoing fixed orthodontics. A randomized, double-blind, placebo-controlled and cross-over clinical trial study was conducted. Subjects were asked to apply a placebo gel and 5% benzocaine gel, exchangeable in two consecutive appointments, twice a day for 3 days and mark their level of pain on a VAS scale. The pain severity was evaluated by means of Mann-Whitney U-test for comparing two gel groups, Kruskal-Wallis nonparametric test for overall differences and post hoc test of Dunnett for paired multiple comparisons. p-value was assigned <0.05. The overall mean value of pain intensity for benzocaine and placebo gels was 0.89 and 1.15, respectively. The Mann-Whitney U-test indicated that there was no significant difference between overall pain in both groups (mean difference = 0.258 p ˂ 0.21). For both groups, pain intensity was significantly lower at 2, 6 and 24 h compared with pain experienced at days 2, 3 and 7. Benzocaine gel caused a decrease in pain perception at 2 h compared with placebo gel. Peak pain intensity was at 2 h for placebo gel and at 6 h for benzocaine gel, followed by a decline in pain perception from that point to day 7 for both gels. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Laboratory-scale production of adu gels by external gelation for an intermediate HTGR nuclear

    International Nuclear Information System (INIS)

    S Simbolon; SR Susilowati

    2015-01-01

    The The aim of this research is to produce thousands of microsphere ADU (Ammonium Diuranate) gels by using external gelation for an intermediate HTGR (High Temperature Gas-cooled Reactor) nuclear fuel in laboratory-scale. Microsphere ADU gels were based on sol-solution which was made from a homogeneous mixture of ADUN (Acid Deficient Uranyl Nitrate) which was containing uranyl ion in high concentration, a water soluble organic compound PVA (Polyvinyl Alcohol) and THFA (Tetrahydrofurfuryl Alcohol). The simple unified home made laboratory experimental machine was developed to replace test tube experiment method which was once used due to a tiny amount of microsphere ADU gels produced. It consists of four main parts: tank filled sol-solution connecting to peristaltic pump and vibrating nozzle, preliminary gelation and gelation column. The machine has successfully converted 150 mL sol-solution into thousands of drops which produced 120 - 130 drops in each minute in steady state in ammonia gas free sector. Preliminary gelation reaction was carried out in ammonia gas sector where drops react with ammonia gas in a bat an eye followed by gelation reaction in column containing ammonia solution 7 M. In ageing process, ADU gels were collected and submerged into a vessel containing ammonia solution which was shaken for 1 hour in a shaker device. Isopropyl alcohol (90 %) solution was used to wash ADU gels and a digital camera was used to measured spherical form of ADU gels. Diameters in spherical spheroid form were found between 1.8 mm until 2.2 mm. The spherical purity of ADU gels were 10 % - 20 % others were oblate, prolate spheroid and microsphere which have hugetiny of dimples on the surface. (author)

  14. Gel compression considerations for chromatography scale-up for protein C purification.

    Science.gov (United States)

    He, W; Bruley, D F; Drohan, W N

    1998-01-01

    This work is to establish theoretical and experimental relationships for the scale-up of Immobilized Metal Affinity Chromatography (IMAC) and Immuno Affinity Chromatography for the low cost production of large quantities of Protein C. The external customer requirements for this project have been established for Protein C deficient people with the goal of providing prophylactic patient treatment. Deep vein thrombosis is the major symptom for protein C deficiency creating the potential problem of embolism transport to important organs, such as, lung and brain. Gel matrices for protein C separation are being analyzed to determine the relationship between the material properties of the gel and the column collapse characteristics. The fluid flow rate and pressure drop is being examined to see how they influence column stability. Gel packing analysis includes two considerations; one is bulk compression due to flow rate, and the second is gel particle deformation due to fluid flow and pressure drop. Based on the assumption of creeping flow, Darcy's law is being applied to characterize the flow through the gel particles. Biot's mathematical description of three-dimensional consolidation in porous media is being used to develop a set of system equations. Finite difference methods are being utilized to obtain the equation solutions. In addition, special programs such as finite element approaches, ABAQUS, will be studied to determine their application to this particular problem. Experimental studies are being performed to determine flow rate and pressure drop correlation for the chromatographic columns with appropriate gels. Void fraction is being measured using pulse testing to allow Reynolds number calculations. Experimental yield stress is being measured to compare with the theoretical calculations. Total Quality Management (TQM) tools have been utilized to optimize this work. For instance, the "Scatter Diagram" has been used to evaluate and select the appropriate gels and

  15. Poloxamer-based thermoresponsive ketorolac tromethamine in situ gel preparations: Design, characterisation, toxicity and transcorneal permeation studies.

    Science.gov (United States)

    M A Fathalla, Zeinab; Vangala, Anil; Longman, Michael; Khaled, Khaled A; Hussein, Amal K; El-Garhy, Omar H; Alany, Raid G

    2017-05-01

    This study was aimed at preparing, characterising and evaluating in situ gel formulations based on a blend of two hydrophilic polymers i.e. poloxamer 407 (P407) and poloxamer 188 (P188) for a sustained ocular delivery of ketorolac tromethamine (KT). Drug-polymer interaction studies were performed using DSC and FT-IR. The gelation temperature (T sol-gel ), gelation time, rheological behaviour, mucoadhesive characteristics of these gels, transcorneal permeation and ocular irritation as well as toxicity was investigated. DSC and FT-IR studies revealed that there may be electrostatic interactions between the drug and the polymers used. P188 modified the T sol/gel of P407 bringing it close to eye temperature (35°C) compared with the formulation containing P407 alone. Moreover, gels that comprised P407 and P188 exhibited a pseudoplastic behaviour at different concentrations. Furthermore, mucoadhesion study using mucin discs showed that in situ gel formulations have good mucoadhesive characteristics upon increasing the concentration of P407. When comparing formulations PP11 and PP12, the work of adhesion decreased significantly (P<0.001) from 377.9±7.79mNmm to 272.3±6.11mNmm. In vitro release and ex vivo permeation experiments indicated that the in situ gels were able to prolong and control KT release as only 48% of the KT released within 12h. In addition, the HET-CAM and BCOP tests confirmed the non-irritancy of KT loaded in situ gels, and HET-CAM test demonstrated the ability of ocular protection against strongly irritant substances. MTT assay on primary corneal epithelial cells revealed that in situ gel formulations loaded with KT showed reasonable and acceptable percent cell viability compared with control samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Titanium (IV) sol-gel chemistry in varied gravity environments

    Science.gov (United States)

    Hales, Matthew; Martens, Wayde; Steinberg, Theodore

    Sol-gel synthesis in reduced gravity is a relatively new topic in the literature and further inves-tigation is essential to realise its potential and application to other sol-gel systems. The sol-gel technique has been successfully applied to the synthesis of silica systems of varying porosity for many diverse applications [1-5]. It is proposed that current methods for the synthesis of silica sol-gels in reduced gravity may be applied to titanium sol-gel processing in order to enhance desirable physical and chemical characteristics of the final materials. The physical and chemical formation mechanisms for titanium alkoxide based sol-gels, to date, is not fully understood. However, various authors [6-9] have described potential methods to control the hydrolysis and condensation reactions of titanium alkoxides through the use of chemical inhibitors. A preliminary study of the reaction kinetics of titanium alkoxide sol-gel reaction in normal gravity was undertaken in order to determine reactant mixtures suitable for further testing under varied gravity conditions of limited duration. Through the use of 1H Nuclear Magnetic Resonance spectroscopy (NMR) for structural analysis of precursor materials, Ultra-Violet-Visible spectroscopy (UV-VIS) and viscosity measurements, it was demonstrated that not only could the rate of the chemical reaction could be controlled, but directed linear chain growth within the resulting gel structure was achievable through the use of increased inhibitor concentrations. Two unique test systems have been fabricated to study the effects of varied gravity (reduced, normal, high) on the formation of titanium sol-gels. Whilst the first system is to be used in conjunction with the recently commissioned drop tower facility at Queensland University of Technology in Brisbane, Australia to produce reduced gravity conditions. The second system is a centrifuge capable of providing high gravity environments of up to 70 G's for extended periods of time

  17. Formulasi Gel Pacar Air (Impatiens balsamina Linn. terhadap Propionibacterium acnes dan Staphylococcus epidermidis

    Directory of Open Access Journals (Sweden)

    Diah Ismarani

    2014-04-01

    Full Text Available Acnes vulgaris is a chronic inflammatory disease of sebaceous follicles caused by Propionibacterium acnes and Staphylococcus epidermidis.The antibacterial activity of Impatiens balsamina L. has been studied for many years. The aims of this study were to find out the antiacne effect from methanolic extract of stems and leaves of Impatiens balsamina L. that were formulated in gel. Simplicia were extracted using soxhlet technique using methanol as solvent. Extracts were then formulated in gel in three variations of HPMC 4000 and Carbopol 934 as gel base with ratio of 70:30 (F1, 50:50 (F2 and 30:70 (F3. The determination of antiacne effect was done using disc diffusion method. Evaluation of physical and chemical properties of those gels includes organoleptic examination, spreadability testing, adhesion testing and pH testing. Data were analyzed using R version 2.14.1 package R-commander. Determination results showed the diameter of inhibition zone from FI, FII and FIII for P.acnes were 6.46 ±0.15 mm; 12.16 ± 0.35 mm; 16.13 ± 0.35mm and for S.epidermidis were 14.5 ± 0.47 mm; 16.56 ± 0.651 mm; 17.13 ± 0.44mm. Analysis results showed that gel of FIII gave optimal antiacne effect, but significantly different from positive control (p<0,05. The evaluation of gel showed that they have homogeny texture, good spreadability and adhesion, as well as the pH compliance.

  18. PHARMACOLOGICAL RESEARCH OF THE DENTAL GEL WITH CARBON DIOXIDE HUMULUS LUPULUS EXTRACT

    Directory of Open Access Journals (Sweden)

    Melnik AL

    2017-03-01

    0.0001 to p ≤ 0.0004. During the experiment, the animals of all experimental groups were observed physiological fluctuations that characterize the pattern of peripheral blood. Results of biochemical studies showed that overall the tested parameters: the concentration of total protein, albumin, thymol test, the activity of alanine and aspartate aminotransferase, the concentration of glucose and cholesterol in the blood serum of rats of all experimental groups answered normal values. There have been fluctuations in biochemical parameters in animals of all experimental groups compared with baseline data did not go beyond the physiological norm. Conclusions. 1. Study of acute toxicity after a single intragastric administration to mice gel with 0.5 % carbon dioxide Humulus lupulus extract have shown that gel does not cause death of animals; no toxic effects on the general state, behavior, food consumption and water weight animals; does not affect the absolute and relative weight of internal organs; does not cause visible changes of internal organs. 2. According to the standard classification gel with 0.5 % carbon dioxide Humulus lupulus extract refers to practically non-toxic substances. 3. Subacute toxicity study results showed that the gel with 0.5 % carbon dioxide Humulus lupulus extract with 14 daily intragastric administration to rats at doses of 0.5 g/kg and 1.0 g/kg, does not cause death of animals; has no toxic effects on the general state, behavior and dynamics of body weight of the experimental animals; no negative impact on the performance of blood of animals; does not change the biochemical parameters characterizing the functional state of the liver of animals. 4. Pharmacological studies of dental gel with 0.5 % carbon dioxide Humulus lupulus extract, such as the results of the study of acute and subacute toxicity found that designed gel to include low-toxic substances (IV class of toxicity, has good tolerability and safety of long-term use.

  19. Methyl cellulose gel obstructed bone formation by GBR: an experimental study in rats.

    Science.gov (United States)

    Lioubavina-Hack, Natalia; Karring, Thorkild; Lynch, Samuel E; Lindhe, Jan

    2005-12-01

    To evaluate whether bone formation under Teflon capsules may be enhanced by concomitant implantation of recombinant human platelet-derived growth factor-BB/insulin-like growth factor-I (rhPDGF-BB/IGF-I) incorporated into a methyl cellulose gel. Fifty-five male 6-month-old albino rats of the Wistar strain were used in the study. The lateral aspect of the mandibular ramus was exposed on both sides of the jaw. In 70 sites, the periosteum was removed from the ramus, leaving the bone denuded, while in 35 sites, it was preserved. On 10 non-periosteal (P-) sites and five periosteal (P+) sites, an empty rigid teflon capsule (d=7 mm), serving as control, was placed on the ramus. In the 40 test animals, the capsule placed on the one side of the jaw was filled at random with one of three different concentrations (1,200, 600, 150 microg/ml) of rhPDGF-BB/IGF-I gel. The capsules placed on the contralateral side of the jaw contained a placebo methyl cellulose gel. Each growth factor group, defined according to the gel concentration, and the placebo group contained 10 capsules placed on the P- side and five capsules placed on the P+ side. Two months after surgery, all animals were sacrificed. Histologic analysis revealed that in the non-filled control capsules, the amount of new bone including the bone marrow was 29.9% and 39.7% of the capsule area on the P- and P+ sides, respectively. In the test capsules with the growth factor gel and placed on the P-sides, the amounts of new bone ranged from 5.6% to 6.3%, which were similar (p>0.05) to that formed in the capsules filled with the methyl cellulose gel (5.5%). New bone formation was larger in the capsules on the P+ sides than in those on the P- sides but was similar in the capsules with different growth factor concentrations (range 17.9-19.6%) and in those with placebo gel (21.0%). In all groups, the carrier gel was poorly absorbed and occupied most of the capsules. Local application of a methyl cellulose gel obstructed bone

  20. Enhancement of sweetness intensity in gels by inhomogeneous distribution of sucrose

    NARCIS (Netherlands)

    Mosca, A.C.; Velde, van de F.; Bult, J.H.F.; Boekel, van M.A.J.S.; Stieger, M.A.

    2010-01-01

    Model systems consisting of layers of mixed agar/gelatin gel were used to investigate the effect of the spatial distribution of sucrose on perceived sweetness intensity. 2-Alternative forced choice tests were performed with consumers to compare the sweetness of layered samples with an inhomogeneous

  1. Revealing genetic diversity of eukaryotic microorganisms in aquatic environments by denaturing gradient gel electrophoresis

    NARCIS (Netherlands)

    Van Hannen, E.J.; Van Agterveld, M.P.; Gons, H.J.; Laanbroek, H.J.

    1998-01-01

    A new Eucarya-specific 18S rDNA primer set was constructed and tested using denaturing gradient gel electrophoresis to analyze the genetic diversity of eukaryotic microorganisms in aquatic environments. All eukaryal lines of descent exhibited four or fewer nucleotide mismatches in the forward primer

  2. Separation of hydrolytically active components of cellulase from Myrothecium verrucaria by starch gel electrophoresis

    NARCIS (Netherlands)

    Ritter, F.J.; Prins-van der Meulen, P.Y.F.; Marel, T. van der

    1968-01-01

    Using starch gel electrophoresis according to Smithies, desalted crude cellulase from Myrothecium verrucqria was separated into at least 12 protein zones. These were tested on their activity towards p-nitrophenyl-β-D-glucoside, sodium carboxymethylcellulose and α-cellulose. They were all

  3. Directed shift of vaginal microbiota induced by vaginal application of sucrose gel in rhesus macaques

    Directory of Open Access Journals (Sweden)

    Kai-tao Hu

    2015-04-01

    Conclusions: Rhesus macaques can be used as animal models of bacterial vaginosis to develop drugs and test treatment efficacy. Furthermore, the topical application of sucrose gel induced the shifting of vaginal flora of rhesus macaques from a BV kind of flora to a lactobacilli-dominating flora.

  4. Regulation of annexins following infection like tissue damage – investigated by 2-dimensional gel electrophoresis

    DEFF Research Database (Denmark)

    Wulff, Tune; Nielsen, Michael Engelbrecht

    , internal- and external control were found using a t-test. To investigate numerous proteins in a single study changes in protein abundance were investigated using 2-dimensional gel electrophoresis. Protein of interest were identified using MALDI MS/MS. The results show that both annexin 4 and 5...

  5. Optical-CT scanning of polymer gels

    International Nuclear Information System (INIS)

    Oldham, M

    2004-01-01

    The application of optical-CT scanning to achieve accurate high-resolution 3D dosimetry is a subject of current interest. The purpose of this paper is to provide a brief overview of past research and achievements in optical-CT polymer gel dosimetry, and to review current issues and challenges. The origins of optical-CT imaging of light-scattering polymer gels are reviewed. Techniques to characterize and optimize optical-CT performance are presented. Particular attention is given to studies of artifacts in optical-CT imaging, an important area that has not been well studied to date. The technique of optical-CT simulation by Monte-Carlo modeling is introduced as a tool to explore such artifacts. New simulation studies are presented and compared with experimental data

  6. Gel Fabrication of Molybdenum “Beads”

    Energy Technology Data Exchange (ETDEWEB)

    Lowden, Richard Andrew [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Armstrong, Beth L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Cooley, Kevin M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division

    2016-11-01

    Spherical molybdenum particles or “beads” of various diameters are of interest as feedstock materials for the additive manufacture of targets and assemblies used in the production of 99Mo medical isotopes using accelerator technology. Small metallic beads or ball bearings are typically fabricated from wire; however, small molybdenum spheres cannot readily be produced in this manner. Sol-gel processes are often employed to produce small dense microspheres of metal oxides across a broad diameter range that in the case of molybdenum could be reduced and sintered to produce metallic spheres. These Sol-gel type processes were examined for forming molybdenum oxide beads; however, the molybdenum trioxide was chemically incompatible with commonly used gelation materials. As an alternative, an aqueous alginate process being assessed for the fabrication of oxide spheres for catalyst applications was employed to form molybdenum trioxide beads that were successfully reduced and sintered to produce small molybdenum spheres.

  7. Local mobility and topology in gels

    International Nuclear Information System (INIS)

    Higgins, J.S.; Ma, K.; Hall, R.H.; Warner, M.

    1981-04-01

    In the first section of this two part report entitled 'Separation of the motion around cross-link points from main chain motion in network samples' by Higgins, Ma and Hall, experimental evidence for topologically dependent diffusion in gels and rubbers is presented from high resolution neutron scattering experiments on deuterium labelled model trifunctional networks which show that the junction points move more slowly than the free chain centres by a factor of about two. In the second part by Warner entitled 'The dynamics of particular points on a polymer chain', the diffusional dynamics of particular points of a polymer chain is calculated in the Rouse approximation. The points considered correspond, in the case of incoherent neutron scattering, to the proton-labelled free ends of chains, crosslinks between chains in rubbers or gels, or the central monomers in branched or star polymers. Results derived are also relevant to NMR, ESR and computer simulation experiments. (U.K.)

  8. Solvent induced supramolecular anisotropy in molecular gels

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, Michael A., E-mail: mroger09@uoguelph.ca [Department of Food Science, University of Guelph, Guelph, Ontario, N3C3X9 (Canada); Corradini, Maria G. [Department of Food Science, University of Massachusetts Amherst, Amherst, MA, 01003 (United States); Emge, Thomas [Department of Chemistry and Biochemistry, Rutgers University, New Brunswick, NJ, 08901 (United States)

    2017-06-15

    Herein is the first report of solvent induced anisotropy in 12-hydroxystearic acid self-assembled fibrillar networks. Increasing the chain length of polar solvent, such as nitriles and ketones, tailored the anisotropy of the fibrillar aggregates. 12HSA molecular gels, comprised of alkanes, exhibited an isotropic fibrillar network irrespective of the alkane chain length. In polar solvents, anisotropy, observed using 2D powder x-ray diffraction profiles, is correlated to a fibrillar supramolecular morphologies in long chain nitriles and ketones while sphereulitic crystals are correlated to x-ray diffraction patterns with an isotropic scatter intensity in short chain ketones and nitriles. These changes directly modify the final physical properties of the gels. - Highlights: • 12-HSA self-assembles into crystalline supramolecular morphologies depending on the solvent. • Alkanes, short chain nitriles and ketones led to 12-HSA displaying supramolecular isotropy. • In long chain nitriles and ketones, 12-HSA displays supramolecular anisotropy.

  9. Solvent induced supramolecular anisotropy in molecular gels

    International Nuclear Information System (INIS)

    Rogers, Michael A.; Corradini, Maria G.; Emge, Thomas

    2017-01-01

    Herein is the first report of solvent induced anisotropy in 12-hydroxystearic acid self-assembled fibrillar networks. Increasing the chain length of polar solvent, such as nitriles and ketones, tailored the anisotropy of the fibrillar aggregates. 12HSA molecular gels, comprised of alkanes, exhibited an isotropic fibrillar network irrespective of the alkane chain length. In polar solvents, anisotropy, observed using 2D powder x-ray diffraction profiles, is correlated to a fibrillar supramolecular morphologies in long chain nitriles and ketones while sphereulitic crystals are correlated to x-ray diffraction patterns with an isotropic scatter intensity in short chain ketones and nitriles. These changes directly modify the final physical properties of the gels. - Highlights: • 12-HSA self-assembles into crystalline supramolecular morphologies depending on the solvent. • Alkanes, short chain nitriles and ketones led to 12-HSA displaying supramolecular isotropy. • In long chain nitriles and ketones, 12-HSA displays supramolecular anisotropy.

  10. Gel Evolution in Oil Based Drilling Fluids

    OpenAIRE

    Sandvold, Ida

    2012-01-01

    Drilling fluids make up an essential part of the drilling operation. Successful drilling operations rely on adequate drilling fluid quality. With the development of new drilling techniques such as long deviated sections and drilling in ultra-deep waters, the standard of required performance of the drilling fluids continue to increase. Narrow pressure margins and low tolerance for barite sag requires accurate prediction of the gel evolution in drilling fluids. Increased knowledge of how dri...

  11. Analysis of traumatic ulcer healing time under the treatment of the Mauli banana (Musa acuminata 25% stem extract gel

    Directory of Open Access Journals (Sweden)

    Dewi Puspitasari

    2017-03-01

    Full Text Available ABSTRACT Introduction: Traumatic ulcer is one of oral disorders that often occur. The prevalence is quite high, between 3-24% of population. Therapy of traumatic ulcer is symptomatic. People usually use Aloe vera extract gel. Previous research showed that the Aloe vera gel is equivalent with ethanol extract of 25% Mauli banana (Musa acuminata stem in accelerating wound healing based on the number of macrophages and neovascular. The objective of the study is to find out the time difference of traumatic ulcer healing using 25% Musa acuminata stem extract gel compared to a gel containing Aloe vera extract. Methods: The research was post test design. Subjects were patients of Oral Medicine Installation in Gusti Hasan Aman Dental Hospital Banjarmasin with diagnosis of traumatic ulcer using completely random sampling method. Eight patients as samples were determined by the formula of Lemeshow. Results: there was no significant difference with p=0,724 (p>0,05 between healing time using Aloe vera gel and 25% Musa acuminata stem extract. Conclusion: At the concentration of 25% Musa acuminata stem extract gel concentration has the same healing time with Aloe vera gel, therefore can be recommended as a topical use for traumatic ulcer healing. Keywords: Musa acuminata stem, Healing time, Traumatic ulcer

  12. Antibacterial Activity of Two Chemomechanical Caries Removal Gels on Carious Dentin of Primary Teeth: An in vitro Study.

    Science.gov (United States)

    Gulzar, Shabnam; Arora, Ruchi; Shah, Altaf H; Bhardwaj, Bhupendra; Abusalim, Ghadah; Khalil, Hesham S; Wyne, Amjad H

    2016-12-01

    Chemomechanical caries removal (CMCR) is an effective method of caries removal especially for primary teeth as they cause less discomfort when compared with conventional caries removal. The most significant thing about caries removal is the elimination of cariogenic bacteria. This study compares the antibacterial activity of two CMCR gels. A total of 40 primary molar teeth with carious dentin were split along the long axis in a laboratory. Total viable count (TVC) was taken for the teeth before splitting as a measure of colony-forming units per milliliter (CFU/mL). Each half was treated with either Carisolv or Carie-Care CMCR gels. Clean dentin samples were evaluated for Streptococcus mutans (SM) and Lactobacillus acidophilus (LB) after removal of carious tissue using the caries removal gels using serial dilutions and incubating on specific agar plates. The results showed significant reduction in mean TVC after use of both the CMCR gels. Both gels reduced the CFU/mL of SM and LB to a significant level (p Carie-Care) significantly reduced the residual TVC as well as SM and LB in carious primary dentin. Both CMCR gels had a similar antibacterial activity on the carious dentin of primary teeth. The CMCR gels tested have a significant antibacterial activity and can be effectively used for elimination of caries-causing bacteria in primary teeth.

  13. Alternative Ultrasound Gel for a Sustainable Ultrasound Program: Application of Human Centered Design.

    Directory of Open Access Journals (Sweden)

    Margaret Salmon

    Full Text Available This paper describes design of a low cost, ultrasound gel from local products applying aspects of Human Centered Design methodology. A multidisciplinary team worked with clinicians who use ultrasound where commercial gel is cost prohibitive and scarce. The team followed the format outlined in the Ideo Took Kit. Research began by defining the challenge "how to create locally available alternative ultrasound gel for a low-resourced environment? The "End-Users," were identified as clinicians who use ultrasound in Democratic Republic of the Congo and Ethiopia. An expert group was identified and queried for possible alternatives to commercial gel. Responses included shampoo, oils, water and cornstarch. Cornstarch, while a reasonable solution, was either not available or too expensive. We then sought deeper knowledge of locally sources materials from local experts, market vendors, to develop a similar product. Suggested solutions gleaned from these interviews were collected and used to create ultrasound gel accounting for cost, image quality, manufacturing capability. Initial prototypes used cassava root flour from Great Lakes Region (DRC, Rwanda, Uganda, Tanzania and West Africa, and bula from Ethiopia. Prototypes were tested in the field and resulting images evaluated by our user group. A final prototype was then selected. Cassava and bula at a 32 part water, 8 part flour and 4 part salt, heated, mixed then cooled was the product design of choice.

  14. Alternative Ultrasound Gel for a Sustainable Ultrasound Program: Application of Human Centered Design.

    Science.gov (United States)

    Salmon, Margaret; Salmon, Christian; Bissinger, Alexa; Muller, Mundenga Mutendi; Gebreyesus, Alegnta; Geremew, Haimanot; Wendel, Sarah K; Wendell, Sarah; Azaza, Aklilu; Salumu, Maurice; Benfield, Nerys

    2015-01-01

    This paper describes design of a low cost, ultrasound gel from local products applying aspects of Human Centered Design methodology. A multidisciplinary team worked with clinicians who use ultrasound where commercial gel is cost prohibitive and scarce. The team followed the format outlined in the Ideo Took Kit. Research began by defining the challenge "how to create locally available alternative ultrasound gel for a low-resourced environment? The "End-Users," were identified as clinicians who use ultrasound in Democratic Republic of the Congo and Ethiopia. An expert group was identified and queried for possible alternatives to commercial gel. Responses included shampoo, oils, water and cornstarch. Cornstarch, while a reasonable solution, was either not available or too expensive. We then sought deeper knowledge of locally sources materials from local experts, market vendors, to develop a similar product. Suggested solutions gleaned from these interviews were collected and used to create ultrasound gel accounting for cost, image quality, manufacturing capability. Initial prototypes used cassava root flour from Great Lakes Region (DRC, Rwanda, Uganda, Tanzania) and West Africa, and bula from Ethiopia. Prototypes were tested in the field and resulting images evaluated by our user group. A final prototype was then selected. Cassava and bula at a 32 part water, 8 part flour and 4 part salt, heated, mixed then cooled was the product design of choice.

  15. Mechanical compatibility of sol-gel annealing with titanium for orthopaedic prostheses.

    Science.gov (United States)

    Greer, Andrew I M; Lim, Teoh S; Brydone, Alistair S; Gadegaard, Nikolaj

    2016-01-01

    Sol-gel processing is an attractive method for large-scale surface coating due to its facile and inexpensive preparation, even with the inclusion of precision nanotopographies. These are desirable traits for metal orthopaedic prostheses where ceramic coatings are known to be osteoinductive and the effects may be amplified through nanotexturing. However there are a few concerns associated with the application of sol-gel technology to orthopaedics. Primarily, the annealing stage required to transform the sol-gel into a ceramic may compromise the physical integrity of the underlying metal. Secondly, loose particles on medical implants can be carcinogenic and cause inflammation so the coating needs to be strongly bonded to the implant. These concerns are addressed in this paper. Titanium, the dominant material for orthopaedics at present, is examined before and after sol-gel processing for changes in hardness and flexural modulus. Wear resistance, bending and pull tests are also performed to evaluate the ceramic coating. The findings suggest that sol-gel coatings will be compatible with titanium implants for an optimum temperature of 500 °C.

  16. The development of Cutina lipogels and gel microemulsion for topical administration of fluconazole.

    Science.gov (United States)

    El Laithy, H M; El-Shaboury, K M F

    2002-01-01

    The influence of the vehicle on the release and permeation of fluconazole, a topical antifungal drug dissolved in Jojoba oil was evaluated. Series of Cutina lipogels (Cutina CPA [cetyl palmitate], CBS [mixture of glyceryl stearate, cetearyl alcohol, cetyl palmitate, and cocoglycerides], MD [glyceryl stearate], and GMS [glyceryl monostearate]) in different concentrations as well as gel microemulsion were prepared. In-vitro drug release in Sorensen's citrate buffer (pH 5.5) and permeation through the excised skin of hairless mice, using a modified Franz diffusion cell, were performed. The rheological behavior and the apparent viscosity values for different gel bases were measured before and after storage under freezing conditions at -4 degrees C and were taken as measures for stability of network structure. Candida albicans was used as a model fungus to evaluate the antifungal activity of the best formula achieved. The results of in vitro drug release and its percutaneous absorption showed that the highest values from gel microemulsion were assured. The rheological behavior of the prepared systems showed pseudoplastic (shear-thinning) flow indicating structural breakdown of the existing intermolecular interactions between polymeric chains. Moreover, the stability study revealed no significant difference between viscosity before and after storage for different formulae except for CPA Cutina lipogel (using analysis of variance [ANOVA] test at level of significance.05). The antifungal activity of fluconazole showed the widest zone of inhibition with gel microemulsion. The gel microemulsion is an excellent vehicle for fluconazole topical drug delivery.

  17. Whey protein isolate modified by transglutaminase aggregation and emulsion gel properties

    Science.gov (United States)

    Qi, Weiwei; Chen, Chong; Liu, Mujun; Yu, Guoping; Cai, Xinghang; Guo, Peipei; Yao, Yuxiu; Mei, Sijie

    2015-07-01

    Whey protein isolate and commercial soybean salad oil were used to produce the WPI emulsion dispersions. The properties of TG-catalyzed emulsion gelation produced from WPI emulsion dispersions were investigated by the amount of TG, temperature, pH and reaction time. Specifically, the texture properties (hardness and springiness), water-holding capacity and rheological properties (G' and G") were assessed. The result of Orthogonal tests showed WPI emulsion can form better hardness and springiness gel when the ratio of TG and WPI was 20U/g, pH 7.5, treatment temperature and time were 50°C and 3 h, respectively. The microstructure of TG emulsion gels was more compact, gel pore is smaller, distribution more uniform, the oil droplets size smaller compared with untreated emulsion gels. Compared to the control of rheological properties, G' and G" were significantly increased and G' > G", results showed that the gel was solid state, and TG speeded up the process of gelation.

  18. Rapid heating of Alaska pollock and chicken breast myofibrillar proteins as affecting gel rheological properties.

    Science.gov (United States)

    Liu, Wenjie; Stevenson, Clint D; Lanier, Tyre C

    2013-07-01

    Surimi seafoods (fish/poikilotherm protein) in the U.S.A. are typically cooked rapidly to 90+°C, while comminuted products made from land animals (meat/homeotherm protein) are purposely cooked much more slowly, and to lower endpoint temperatures (near 70 °C). We studied heating rate (0.5, 25, or 90 °C/min) and endpoint temperature (45 to 90 °C) effects on rheological properties (fracture, small strain) of washed myofibril gels derived from fish (Alaska pollock) compared with chicken breast at a common pH (6.75). This was contrasted with published data on gelation kinetics of chicken myosin over the same temperature range. Heating rate had no effect on fracture properties of fish gels but slow heating did yield somewhat stronger, but not more deformable, chicken gels. Maximum gel strength by rapid heating could be achieved within 5 min holding after less than 1 min heating time. Dynamic testing by small strain revealed poor correspondence of the present data to that published for gelling response of chicken breast myosin in the same temperature range. The common practice of reporting small-strain rheological parameters measured at the endpoint temperature was also shown to be misleading, since upon cooling, there was much less difference in rigidity between rapidly and slowly heated gels for either species. © 2013 Institute of Food Technologists®

  19. MALDI analysis of proteins after extraction from dissolvable ethylene glycol diacrylate cross-linked polyacrylamide gels.

    Science.gov (United States)

    Papasotiriou, Dimitrios G; Markoutsa, Stavroula; Gorka, Jan; Schleiff, Enrico; Karas, Michael; Meyer, Bjoern

    2013-09-01

    Although the extraction of intact proteins from polyacrylamide gels followed by mass spectrometric molecular mass determination has been shown to be efficient, there is room for alternative approaches. Our study evaluates ethylene glycol diacrylate, a cleavable cross-linking agent used for a new type of dissolvable gels. It attains an ester linkage that can be hydrolyzed in alkali conditions. The separation performance of the new gel system was tested by 1D and 2D SDS-PAGE using the outer chloroplast envelope of Pisum sativum as well as a soluble protein fraction of human lymphocytes, respectively. Gel spot staining (CBB), dissolving, and extracting were conducted using a custom-developed workflow. It includes protein extraction with an ammonia-SDS buffer followed by methanol treatment to remove acrylamide filaments. Necessary purification for MALDI-TOF analysis was implemented using methanol-chloroform precipitation and perfusion HPLC. Both cleaning procedures were applied to several standard proteins of different molecular weight as well as 'real' biological samples (8-75 kDa). The protein amounts, which had to be loaded on the gel to detect a peak in MALDI-TOF MS, were in the range of 0.1 to 5 μg, and the required amount increased with increasing mass. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Double-network gels and the toughness of terrestrial slug glue.

    Science.gov (United States)

    Wilks, Alex M; Rabice, Sarah R; Garbacz, Holland S; Harro, Cailin C; Smith, Andrew M

    2015-10-01

    The terrestrial slug Arion subfuscus produces a defensive secretion that is sticky and tough, despite being a dilute gel. It is unusual in having high stiffness for a gel, yet retaining the high extensibility typical of mucus. In tensile tests, it sustains an average peak stress of 101 kPa, and fails at an average strain of 9.5. This gives the gel toughness; it requires much greater strain energy to fracture than most gels. This toughness may arise from a double-network type mechanism. In this mechanism, two separate, interpenetrating networks of polymers with different properties combine to give toughness that can be several orders of magnitude greater than either network individually. Native gel electrophoresis suggests that A. subfuscus glue consists of two networks: a network of negatively charged proteins ranging in Mr from 40×10(3) to 220×10(3) that can be dissociated by hydroxylamine and a network of heparan sulfate-like proteoglycans. The two networks are not tightly linked, though proteins of Mr 40×10(3) and 165×10(3) may associate with the carbohydrates. Targeted disruption of either network separately, using enzymatic hydrolysis, disulfide bond breakage or imine bond disruption completely disrupted the glue, resulting in no measurable toughness. Thus, the two networks separately provide little toughness, but together they work synergistically to create a tough material, as predicted in the double-network mechanism. © 2015. Published by The Company of Biologists Ltd.

  1. Effect of Shear History on Rheology of Time-Dependent Colloidal Silica Gels

    Directory of Open Access Journals (Sweden)

    Paulo H. S. Santos

    2017-11-01

    Full Text Available This paper presents a rheological study describing the effects of shear on the flow curves of colloidal gels prepared with different concentrations of fumed silica (4%, 5%, 6%, and 7% and a hydrophobic solvent (Hydrocarbon fuel, JP-8. Viscosity measurements as a function of time were carried out at different shear rates (10, 50, 100, 500, and 1000 s−1, and based on this data, a new structural kinetics model was used to describe the system. Previous work has based the analysis of time dependent fluids on the viscosity of the intact material, i.e., before it is sheared, which is a condition very difficult to achieve when weak gels are tested. The simple action of loading the gel in the rheometer affects its structure and rheology, and the reproducibility of the measurements is thus seriously compromised. Changes in viscosity and viscoelastic properties of the sheared material are indicative of microstructural changes in the gel that need to be accounted for. Therefore, a more realistic method is presented in this work. In addition, microscopical images (Cryo-SEM were obtained to show how the structure of the gel is affected upon application of shear.

  2. Sol-Gel Chemistry for Carbon Dots.

    Science.gov (United States)

    Malfatti, Luca; Innocenzi, Plinio

    2018-03-14

    Carbon dots are an emerging class of carbon-based nanostructures produced by low-cost raw materials which exhibit a widely-tunable photoluminescence and a high quantum yield. The potential of these nanomaterials as a substitute of semiconductor quantum dots in optoelectronics and biomedicine is very high, however they need a customized chemistry to be integrated in host-guest systems or functionalized in core-shell structures. This review is focused on recent advances of the sol-gel chemistry applied to the C-dots technology. The surface modification, the fine tailoring of the chemical composition and the embedding into a complex nanostructured material are the main targets of combining sol-gel processing with C-dots chemistry. In addition, the synergistic effect of the sol-gel precursor combined with the C-dots contribute to modify the intrinsic chemo-physical properties of the dots, empowering the emission efficiency or enabling the tuning of the photoluminescence over a wide range of the visible spectrum. © 2018 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Sol-gel bonding of silicon wafers

    International Nuclear Information System (INIS)

    Barbe, C.J.; Cassidy, D.J.; Triani, G.; Latella, B.A.; Mitchell, D.R.G.; Finnie, K.S.; Bartlett, J.R.; Woolfrey, J.L.; Collins, G.A.

    2005-01-01

    Low temperature bonding of silicon wafers was achieved using sol-gel technology. The initial sol-gel chemistry of the coating solution was found to influence the mechanical properties of the resulting bonds. More precisely, the influence of parameters such as the alkoxide concentration, water-to-alkoxide molar ratio, pH, and solution aging on the final bond morphologies and interfacial fracture energy was studied. The thickness and density of the sol-gel coating were characterised using ellipsometry. The corresponding bonded specimens were investigated using attenuated total reflectance Fourier transformed infrared spectroscopy to monitor their chemical composition, infrared imaging to control bond integrity, and cross-sectional transmission electron microscopy to study their microstructure. Their interfacial fracture energy was measured using microindentation. An optimum water-to-alkoxide molar ratio of 10 and hydrolysis water at pH = 2 were found. Such conditions led to relatively dense films (> 90%), resulting in bonds with a fracture energy of 3.5 J/m 2 , significantly higher than those obtained using classical hydrophilic bonding (typically 1.5-2.5 J/m 2 ). Ageing of the coating solution was found to decrease the bond strength

  4. Gel Electrophoresis of Gold-DNA Nanoconjugates

    Directory of Open Access Journals (Sweden)

    T. Pellegrino

    2007-01-01

    Full Text Available Gold-DNA conjugates were investigated in detail by a comprehensive gel electrophoresis study based on 1200 gels. A controlled number of single-stranded DNA of different length was attached specifically via thiol-Au bonds to phosphine-stabilized colloidal gold nanoparticles. Alternatively, the surface of the gold particles was saturated with single stranded DNA of different length either specifically via thiol-Au bonds or by nonspecific adsorption. From the experimentally determined electrophoretic mobilities, estimates for the effective diameters of the gold-DNA conjugates were derived by applying two different data treatment approaches. The first method is based on making a calibration curve for the relation between effective diameters and mobilities with gold nanoparticles of known diameter. The second method is based on Ferguson analysis which uses gold nanoparticles of known diameter as reference database. Our study shows that effective diameters derived from gel electrophoresis measurements are affected with a high error bar as the determined values strongly depend on the method of evaluation, though relative changes in size upon binding of molecules can be detected with high precision. Furthermore, in this study, the specific attachment of DNA via gold-thiol bonds to Au nanoparticles is compared to nonspecific adsorption of DNA. Also, the maximum number of DNA molecules that can be bound per particle was determined.

  5. Epoxy Sol-Gel Hybrid Thermosets

    Directory of Open Access Journals (Sweden)

    Angels Serra

    2016-02-01

    Full Text Available Sol-gel methodologies are advantageous in the preparation of hybrid materials in front of the conventional addition of nanoparticles, because of the fine dispersion of the inorganic phase that can be reached in epoxy matrices. In addition, the use of organoalkoxysilanes as coupling agents allows covalent linkage between organic and inorganic phases, which is the key point in the improvement of mechanical properties. The sol-gel process involves hydrolysis and condensation reactions under mild conditions, starting from hydrolysable metal alkoxides, generally alkoxy silanes. Using the sol-gel procedure, the viscosity of the formulation is maintained, which is an important issue in coating applications, whereas the transparency of the polymer matrix is also maintained. However, only the proper combination of the chemistries and functionalities of both organic and inorganic structures leads to thermosets with the desired characteristics. The adequate preparation of hybrid epoxy thermosets enables their improvement in characteristics such as mechanical properties (modulus, hardness, scratch resistance, thermal and flame resistance, corrosion and antimicrobial protection, and even optical performance among others.

  6. Effect of the exothermal polymerization reaction on polymer gel dosimetric measurements

    International Nuclear Information System (INIS)

    Sedaghat, Mahbod; Bujold, Rachel; Lepage, Martin

    2010-01-01

    Discrepancies in polymer gel dosimetric measurements have been observed between containers of different sizes receiving the same radiation dose. We hypothesized that these deviations are caused by a change in the rate of polymerization due to internal heat increase in the gel containers resulting from the exothermic polymerization of monomers. Here, we test this hypothesis in a polyacrylamide gel dosimeter by recording the temperature in glass phantoms of different sizes during and after irradiation. The dose response of the samples was determined with magnetic resonance imaging. The difference of R 2 values along the depth of the containers was below ±1%. We discuss that this small difference can be attributed to variations in the rate of gelatin cooling during manufacture rather than to the measured heat increase during irradiation.

  7. Alkaline gel electrophoresis assay to detect DNA strand breaks and repair mechanisms in Escherichia coli

    International Nuclear Information System (INIS)

    Mattos, Jose Carlos Pelielo de; Motta, Ellen Serri da; Oliveira, Marcia Betania Nunes de; Dantas, Flavio Jose da Silva; Araujo, Adriano Caldeira de

    2008-01-01

    Reactive oxygen species (ROS) can induce lesions in different cellular targets, including DNA. Stannous chloride (SnCl 2 ) is a ROS generator, leading to lethality in Escherichia coli (E. coli), with the base excision repair (BER) mechanism playing a role in this process. Many techniques have been developed to detect genotoxicity, as comet assay, in eukaryotic cells, and plasmid DNA agarose gel electrophoresis. In this study, an adaptation of the alkaline gel electrophoresis method was carried out to ascertain the induction of strand breaks by SnCl 2 in bacterial DNA, from E. coli BER mutants, and its repair pathway. Results obtained show that SnCl 2 was able to induce DNA strand breaks in all strains tested. Moreover, endonuclease IV and exonuclease III play a role in DNA repair. On the whole, data has shown that the alkaline gel electrophoresis assay could be used both for studying DNA strand breaks induction and for associated repair mechanisms. (author)

  8. Effects of platelet-rich plasma gel on skin healing in surgical wound in horses.

    Science.gov (United States)

    DeRossi, Rafael; Coelho, Anna Carolina Anciliero de Oliveira; Mello, Gisele Silveira de; Frazílio, Fabrício Oliveira; Leal, Cássia Rejane Brito; Facco, Gilberto Gonçalves; Brum, Karine Bonucielli

    2009-01-01

    To establish a low-cost method to prepare platelet-rich plasma (PRP) and evaluates the potential of platelet derived factors to enhance wound healing in the surgical wounds in equine. To obtain a PRP gel, calcium gluconate and autologous thrombin were added to platelet-rich plasma. For the tests six saddle horses were used and two surgical incisions were made in each animal. Wounds were treated with PRP gel or untreated. Sequential wound biopsies collected at Treatment 1: at days 5 and 30 and Treatment 2: at days 15 and 45 post wounding permitted comparison of differentiation markers and wound repair. The optimal platelets enrichment over 4.0 time's baseline values was obtained using 300 g for 10 min on the first centrifugation and 640 g for 10 min on the second centrifugation. Wounds treated with PRP gel exhibit more rapid epithelial differentiation and enhanced organization of dermal collagen compared to controls in equine.

  9. Role of gel dosimeters in boron neutron capture therapy

    International Nuclear Information System (INIS)

    Khajeali, Azim; Farajollahi, Ali Reza; Khodadadi, Roghayeh; Kasesaz, Yaser; Khalili, Assef

    2015-01-01

    Gel dosimeters have acquired a unique status in radiotherapy, especially with the advent of the new techniques in which there is a need for three-dimensional dose measurement with high spatial resolution. One of the techniques in which the use of gel dosimeters has drawn the attention of the researchers is the boron neutron capture therapy. Exploring the history of gel dosimeters, this paper sets out to study their role in the boron neutron capture therapy dosimetric process. - Highlights: • Gel dosimeters have been investigated. • Conventional dosimetric proses of BNCT has been investigated. • Role of gel dosimeters in BNCT has been investigated

  10. Design and Development of Repaglinide Microemulsion Gel for Transdermal Delivery.

    Science.gov (United States)

    Shinde, Ujwala A; Modani, Sheela H; Singh, Kavita H

    2018-01-01

    Microemulsion formulation of repaglinide, a BCS class II hypoglycemic agent with limited oral bioavailability, was developed considering its solubility in various oils, surfactants, and cosurfactants. The pseudo-ternary phase diagrams for microemulsion regions were constructed by water titration method at K m 1:1 and characterized for optical birefringence, percentage transmittance, pH, refractive index, globule size, zeta potential, viscosity, drug content, and thermodynamic stability. To enhance the drug permeation and residence time, the optimized microemulsions having mean globule size of 36.15 ± 9.89 nm was gelled with xanthan gum. The developed microemulsion-based gel was characterized for globule size, zeta potential, pH, and drug content. All evaluation parameters upon gelling were found to be satisfactory. Ex vivo permeability study across rat skin demonstrated higher steady-state flux (P RPG) suspension. In vivo efficacy study was performed in normal Sprague-Dawley rats by using oral glucose tolerance test. Results of RPG transdermal microemulsion gel demonstrated remarkable advantage over orally administered RPG by reducing the glucose level in controlled manner. Hence, it could be a new, alternative dosage form for effective therapy of type 2 diabetes mellitus.

  11. Colloid molecular weight estimation by gel chromatography/acrylamide gel electrophoresis

    International Nuclear Information System (INIS)

    Liberatore, F.A.; Dearborn, C.; Nigam, S.; Poon, C.; Camin, L.; Liteplo, M.

    1984-01-01

    Size or molecular weight (MW) estimation of radiolabeled collides in aqueous solutions has long been a problem. The authors have prepared several minimicroaggregated albumin colloids (mμAA) by heat denaturation of stannous-containing HSA solutions at pH 7.0, 7.5, and 8.5). The resulting colloids were labeled with Tc-99m and compared with Au-198 colloid and Tc-99m-antimony sulfide colloid (Tc-99m-Sb/sub 2/S3) by gel chromatography and gel electrophoresis. Tc-99mm-mμAA aggregated at pH 7.0 and the Au-198 colloid appeared in the external void volume of a BioRad A5.0 agarose column indicating an apparent MW of > 5 x 10/sup 6/ daltons. The pH7.5 Tc-99m-mμAA, migrated within the filtration range of the column as did a small fraction of Tc-99m-Sb/sub 2/S/sub 3/, suggesting that the MW is between 6 x 10/sup 4/ - 5 x 10/sup 6/ daltons. The Tc-99m-mμAA, aggregated at pH 8.5, had an apparent MW on gel filtration similar to that of untreated albumin, MW 6.6 x 10-/sup 4/ daltons. The mobilities of the colloids, on acrylamide disc gel electrophoresis, were consistent with the results on gel chromatography. The largest colloids, Au-198 colloid and pH 7.0 Tc-99m-mμAA, barely entered the separating gel; intermediate sized colloids, a small fraction of Tc-99m-Sb/sub 2/S/sub 3/ and pH 7.5 Tc-99m-mμAA migrated farther into the separating gel; while pH 8.5 Tc-99m-mμAA had mobility approaching that of untreated albumin. Lymphoscintigraphy studies using these colloids in animals showed the predicted, particle size-related differences in migration and clearance. The authors conclude that gel chromatography and gel electrophoresis are useful methods for estimating the apparent size of the colloidal particles

  12. Modelling of the inhomogeneous interior of polymer gels

    International Nuclear Information System (INIS)

    Shew, C-Y; Iwaki, Takafumi

    2006-01-01

    A simple model has been investigated to elucidate the mean squared displacement (MSD) of probe molecules in cross-linked polymer gels. In the model, we assume that numerous cavities distribute in the inhomogeneous interior of a gel, and probe molecules are confined within these cavities. The individual probe molecules trapped in a gel are treated as Brownian particles confined to a spherical harmonic potential. The harmonic potential is chosen to model the effective potential experienced by the probe particle in the cavity of a gel. Each field strength is corresponding to the characteristic of one type of effective cavity. Since the statistical distribution of different effective cavity sizes is unknown, several distribution functions are examined. Meanwhile, the calculated averaged MSDs are compared to the experimental data by Nisato et al (2000 Phys. Rev. E 61 2879). We find that the theoretical results of the MSD are sensitive to the shape of the distribution function. For low cross-linked gels, the best fit is obtained when the interior cavities of a gel follow a bimodal distribution. Such a result may be attributed to the presence of at least two distinct classes of cavity in gels. For high cross-linked gels, the cavities in the gel can be depicted by a single-modal uniform distribution function, suggesting that the range of cavity sizes becomes smaller. These results manifest the voids inside a gel, and the shape of distribution functions may provide the insight into the inhomogeneous interior of a gel

  13. Antioxidant effect of green tea on polymer gel dosimeter

    International Nuclear Information System (INIS)

    Samuel, E J J; Sathiyaraj, P; Deena, T; Kumar, D S

    2015-01-01

    Extract from Green Tea (GTE) acts as an antioxidant in acrylamide based polymer gel dosimeter. In this work, PAGAT gel was used for investigation of antioxidant effect of GTE.PAGAT was called PAGTEG (Polyacrylamide green tea extract gel dosimeter) after adding GTE. Free radicals in water cause pre polymerization of polymer gel before irradiation. Polyphenols from GTE are highly effective to absorb the free radicals in water. THPC is used as an antioxidant in polymer gel dosimeter but here we were replaced it by GTE and investigated its effect by spectrophotometer. GTE added PAGAT samples response was lower compared to THPC added sample. To increase the sensitivity of the PAGTEG, sugar was added. This study confirmed that THPC was a good antioxidant for polymer gel dosimeter. However, GTE also can be used as an antioxidant in polymer gel if use less quantity (GTE) and add sugar as sensitivity enhancer

  14. Antioxidant effect of green tea on polymer gel dosimeter

    Science.gov (United States)

    Samuel, E. J. J.; Sathiyaraj, P.; Deena, T.; Kumar, D. S.

    2015-01-01

    Extract from Green Tea (GTE) acts as an antioxidant in acrylamide based polymer gel dosimeter. In this work, PAGAT gel was used for investigation of antioxidant effect of GTE.PAGAT was called PAGTEG (Polyacrylamide green tea extract gel dosimeter) after adding GTE. Free radicals in water cause pre polymerization of polymer gel before irradiation. Polyphenols from GTE are highly effective to absorb the free radicals in water. THPC is used as an antioxidant in polymer gel dosimeter but here we were replaced it by GTE and investigated its effect by spectrophotometer. GTE added PAGAT samples response was lower compared to THPC added sample. To increase the sensitivity of the PAGTEG, sugar was added. This study confirmed that THPC was a good antioxidant for polymer gel dosimeter. However, GTE also can be used as an antioxidant in polymer gel if use less quantity (GTE) and add sugar as sensitivity enhancer.

  15. Anion-switchable supramolecular gels for controlling pharmaceutical crystal growth

    Science.gov (United States)

    Foster, Jonathan A.; Piepenbrock, Marc-Oliver M.; Lloyd, Gareth O.; Clarke, Nigel; Howard, Judith A. K.; Steed, Jonathan W.

    2010-12-01

    We describe the use of low-molecular-weight supramolecular gels as media for the growth of molecular crystals. Growth of a range of crystals of organic compounds, including pharmaceuticals, was achieved in bis(urea) gels. Low-molecular-weight supramolecular gelators allow access to an unlimited range of solvent systems, in contrast to conventional aqueous gels such as gelatin and agarose. A detailed study of carbamazepine crystal growth in four different bis(urea) gelators, including a metallogelator, is reported. The crystallization of a range of other drug substances, namely sparfloxacin, piroxicam, theophylline, caffeine, ibuprofen, acetaminophen (paracetamol), sulindac and indomethacin, was also achieved in supramolecular gel media without co-crystal formation. In many cases, crystals can be conveniently recovered from the gels by using supramolecular anion-triggered gel dissolution; however, crystals of substances that themselves bind to anions are dissolved by them. Overall, supramolecular gel-phase crystallization offers an extremely versatile new tool in pharmaceutical polymorph screening.

  16. Different Applications of Rheological Techniques in Studies of Physical Gels

    DEFF Research Database (Denmark)

    Hvidt, Søren

    ] pointed out the importance of time scales for physical gels. According to him the characteristic property of a gel is the presence of two components and a constant elastic storage modulus on time scales of 1 s or frequencies of 1 rad/s. His definition of gels relies on their rheological properties......Physical gels are of both great scientific and practical interest. The cytoplasm of cells, which consists of a complex physical gel of protein filaments, is important for most of the cellular processes including cell division and cell motility. Nature has developed this complex system......-forming biopolymers. Physical gels are also used in the paint industry to minimize sedimentation. Delayed and controlled drug release is of importance in the pharmaceutical industry, and one way to obtain this control is to hide active components in physical gels. Two excellent reviews cover many aspects...

  17. High-strength cellulose/poly(ethylene glycol) gels.

    Science.gov (United States)

    Liang, Songmiao; Wu, Junjie; Tian, Huafeng; Zhang, Lina; Xu, Jian

    2008-01-01

    Cellulose gel membranes have been prepared by a pre-gelation method employing cellulose solutions in aqueous NaOH-thiourea obtained at low temperature. The cellulose gels were then swollen by low-molecular-weight polyethylene glycol (PEG; MWcellulose/PEG gels were studied by various techniques. The gels exhibit high mechanical performance, and the tensile strength of the gel membranes increases sharply with an increase in the molecular weight of PEG from 200 to 800 g mol(-1). Moreover, their elongation at break remains stable at 100 %. PEG800 efficiently improves the optical transmittance of the gel membranes at ambient temperature, which is about five times greater than that of a normal cellulose hydrogel membrane. A strong hydrogen-bonding interaction occurs between PEG and cellulose leading to a homogeneous structure, high mechanical strength and good transparency of the gel membranes.

  18. CHARACTERISTICS OF INTERACTIONS BETWEEN SOME TEXTURE PROPERTIES AND COMPOSITION OF CARRAGEENAN GELS AS A RESULT OF ITS DEFINED DIVERSIFIED FREEZING AND THAWING TREATMENT

    Directory of Open Access Journals (Sweden)

    Katarzyna Kozłowicz

    2013-06-01

    Full Text Available Model samples of carrageenan gels based on water, milk and juice were air-blast frozen and frozen by immersion in glycol and in liquid nitrogen. The gel freezing rate was determined on the basis of the kinetics of freezing. Carrageenan gel samples were characterized by evaluation of its thawing drip loss and hardness determined with compression and penetration tests. Freezing in liquid nitrogen ensured the highest freezing rates. Thawing drip loss of gels significantly depended on the carrageenan content, pH of the solution, freezing method and freezing rate. The resulting relationships are linear functions with high determination coefficients. The results of compression and penetration tests prove the significant effect of the carrageenan content and pH on gel hardness. The higher carrageenan content in a sample, the higher compression force and penetration of the gel. Gel freezing resulted in lower hardness. Freezing conditions had a significant effect on the properties tested. The correlation between compression forces and penetration depending on the carrageenan content and the freezing method was described using regression equations with high determination coefficients. Gels based on milk and juice with 2.2% carrageenan content are recommended for immersion freezing at rates above 5.0 cm·h-1.

  19. Agarose gel electrophoresis and polyacrylamide gel electrophoresis for visualization of simple sequence repeats.

    Science.gov (United States)

    Anderson, James; Wright, Drew; Meksem, Khalid

    2013-01-01

    In the modern age of genetic research there is a constant search for ways to improve the efficiency of plant selection. The most recent technology that can result in a highly efficient means of selection and still be done at a low cost is through plant selection directed by simple sequence repeats (SSRs or microsatellites). The molecular markers are used to select for certain desirable plant traits without relying on ambiguous phenotypic data. The best way to detect these is the use of gel electrophoresis. Gel electrophoresis is a common technique in laboratory settings which is used to separate deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) by size. Loading DNA and RNA onto gels allows for visualization of the size of fragments through the separation of DNA and RNA fragments. This is achieved through the use of the charge in the particles. As the fragments separate, they form into distinct bands at set sizes. We describe the ability to visualize SSRs on slab gels of agarose and polyacrylamide gel electrophoresis.

  20. Potential Effect of 2% Chlorhexidine Gel in the Implant Screw Hole on Bacterial Count

    Directory of Open Access Journals (Sweden)

    Abd Khudair Ali

    2017-11-01

    Full Text Available Background: Microbial penetration inside the implant’s internal hole creates a bacterial reservoir that is related with an area of inflamed connective tissue opposite the fixture-abutment junction and this can affect with the health of the peri-implant tissue. Chlorhexidine (CHX has been used to prevent internal implant contamination as a 0.2% solution, a varnish or gel. Aim: To evaluate the aerobic/anaerobic bacterial count-reduction potential of 2% CHX gel placed, at the time of surgery, in the implant screw hole over a period of minimum 90 d, and to monitor the periodontal health status of all patients, throughout the study. Material and methods: Ten partially edentulous patients received 30 DI and these implants were randomly allocated in to: Group I (test 15 implants applied by flap or flapless surgery with 2% CHX gel application. Group II (control 15 implants applied by flap or flapless surgery without CHX gel application. All patients were examined clinically to determine their oral health status by examination of their plaque index, PLI, Gingival index GI, Bleeding on probing, BOP, and probing pocket depth, PPD, every two weeks throughout the study. Three months later, the plaque sample was collected from the internal hole of fixture and was sent for bacteriological examination. Results: The present study shows highly significant reduction of aerobic count of bacteria from 52.1% to 100%. Also, anaerobic bacterial count was reduced from 64.6% to 100% for group that received 2% CHX gel in screw hole of implants at time of surgery. When compared, the count of aerobic and anaerobic bacteria (CFU between test and control group, a significant reduction was found. Conclusion: The use of 2% CHX gel at the time of placement can significantly reduce bacterial counts in the implant screw hole, and this effect can be maintained for 90 d or longer.

  1. Evaluation of ciprofloxacin and metronidazole encapsulated biomimetic nanomatrix gel onEnterococcus faecalisandTreponema denticola.

    Science.gov (United States)

    Kaushik, Sagar N; Scoffield, Jessica; Andukuri, Adinarayana; Alexander, Grant C; Walker, Taneidra; Kim, Seokgon; Choi, Sung Chul; Brott, Brigitta C; Eleazer, Paul D; Lee, Jin-Yong; Wu, Hui; Childers, Noel K; Jun, Ho-Wook; Park, Jae-Hong; Cheon, Kyounga

    2015-06-01

    A triple antibiotic mixture (ciprofloxacin; CF, metronidazole; MN, and minocycline; MC) has been used for dental root canal medicaments in pulp regeneration therapy. However, tooth discolorations, cervical root fractures, and inadequate pulp-dentin formation have been reported due to the triple antibiotic regimen. Therefore, an antibiotic encapsulated biomimetic nanomatrix gel was developed to minimize the clinical limitations and maximize a natural healing process in root canal infections. In this study, minimal bacterial concentrations (MBC) of the selected antibiotics (CF and MN) were tested in 14 representative endodontic bacterial species. Then MBC of each CF and MN were separately encapsulated within the injectable self-assembled biomimetic nanomatrix gel to evaluate antibacterial level on Enterococcus faecalis and Treponema denticola . Antibiotic concentrations lower than 0.2 µg/mL of CF and MN demonstrated antibacterial activity on the 14 endodontic species. Furthermore, 6 different concentrations of CF and MN separately encapsulated with the injectable self-assembled biomimetic nanomatrix gel demonstrated antibacterial activity on Enterococcus faecalis and Treponema denticola at the lowest tested concentration of 0.0625 µg/mL. These results suggest that each CF and MN encapsulated within the injectable self-assembled biomimetic nanomatrix gel demonstrated antibacterial effects, which could be effective for the root canal disinfection while eliminating MC. In the long term, the antibiotic encapsulated injectable self-assembled biomimetic nanomatrix gel can provide a multifunctional antibiotic delivery method with potential root regeneration. Further studies are currently underway to evaluate the effects of combined CF and MN encapsulated within the injectable self-assembled biomimetic nanomatrix gel on clinical samples.

  2. Effectivity of Betel Leaf (Piper betle L. Gel Extract in Shortening Bleeding Time After Deciduous Tooth Extraction

    Directory of Open Access Journals (Sweden)

    Regina Tedjasulaksana

    2017-01-01

    Full Text Available Background: As an Indonesian traditional medicine, betel leafis often used to stop nosebleed. Effective substances in betel leaves which serves to stop the bleeding is tannin. Objective: The aim of this study was to determine the effectiveness of the betel leaf ethanol extract gel shortened bleeding time after the revocation of deciduous teeth. Method: This research was conducted at the Department of Dental Nursing Clinic, Health Polytechnic Denpasar.This study is pure experimental research design with Completely Randomized Post Test Only Control Group Design. The total sample of 27 respondents were divided into a treatment group and two control groups. Anterior deciduous teeth on the physiological loose grade 3 or 4 is extracted, then the tooth socket is put pure gel for group 1 to group 2, epinephrine gel and gel ethanol extract of betel leaf for group 3. The bleeding time is calculated from the first moment the blood out until there is blood on filter paper that is placed on the tooth socket. Data were statistically analyzed with descriptive test and comparability test with One Way Anova. Result: The results showed bleeding time pure gel groups differ significantly with epinephrine group and the group of ethanol extract of betel leaf gel (p< 0.05. Bleeding time of epinephrine group did not differ significantly with betel leaf ethanol extract group (p>0.05. Conclusion: This means ethanol gel betel leaf extract can shorten bleeding after deciduous tooth extraction and it is suggested that the use of gel ethanol extract of betel leaves to cope with bleeding after tooth extraction.

  3. KEKUATAN GEL GELATIN TIPE B DALAM FORMULASI GRANUL TERHADAP KEMAMPUAN MUKOADHESIF

    Directory of Open Access Journals (Sweden)

    Astri Fajriani

    2009-06-01

    Full Text Available Type B Gelatin Gel Strength in Granule Formulation and its Mucoadhesive Characteristics. Mucoadhesive test of polymer excipient is important for development of oral sustained release dosage form in mucoadhesive system to increase bioavailability of a drug. The study focused on mucoadhesive strength of gelatinus granules in stomach and intestine of rat using bioadhesive and wash off tests. Gelatin is a substance obtained from partially hydrolyzed collagen of skin, white cattle bones and animal bones. Gelatin derived from acid process is called type A gelatin and those from alkali process is called type B gelatin. This research studied the influence of various gel strength of type B gelatins, particularly their mucoadhesive characteristics. Mucoadhesive tests were performed at the concentration of 7.14%, 3.66%, and 2.45% and with gel strength of 328 g Bloom, 230 g Bloom and 119 g Bloom respectively. The results showed that granules formula with 230 g Bloom gel strength showed the best mucoadhesive strength, with adhesion percentage of 100%.

  4. Performance comparison of capillary and agarose gel electrophoresis for the identification and characterization of monoclonal immunoglobulins.

    Science.gov (United States)

    McCudden, Christopher R; Mathews, Stephanie P; Hainsworth, Shirley A; Chapman, John F; Hammett-Stabler, Catherine A; Willis, Monte S; Grenache, David G

    2008-03-01

    The objective of this study was to compare gel- and capillary-based serum protein electrophoresis methods to identify and characterize monoclonal immunoglobulins (M proteins). Five reviewers interpreted 149 consecutively ordered serum specimens following agarose gel electrophoresis (AGE), capillary electrophoresis (CE), immunofixation electrophoresis (IFE), and subtraction immunotyping (IT). As a screening test for detecting M proteins, AGE and CE displayed similar sensitivity (91% and 92%, respectively). CE was less specific (74%) than AGE (81%). An analysis of interinterpreter agreement revealed that interpretations were more consistent using gel-based methods than capillary-based methods, with 80% of the gel interpretations being in complete (5/5) agreement compared with 67% of the capillary interpretations. After implementing the capillary-based methods, the number of tests per reportable result increased (from 1.58 to 1.73). CE is an analytically suitable alternative to AGE, but laboratories implementing it will need to continue IFE testing to characterize all M proteins detected by CE.

  5. An in vivo and in vitro investigation of the effect of Aloe vera gel ethanolic extract using animal model with diabetic foot ulcer

    Directory of Open Access Journals (Sweden)

    Mohan Daburkar

    2014-01-01

    Full Text Available Aim: To examine the preventive effect of Aloe vera gel ethanolic extract using diabetic foot ulcer (DFUs protocol in Wistar rats. Materials and Methods: Male Wistar rats were divided into untreated control (Group I, untreated DFUs (Group II, DFUs treated with A. vera gel ethanolic extract (Group III, DFUs treated with topical A. vera gel (Group IV, DFUs treated with A. vera gel ethanolic extract and topical A. vera gel (Group V. The rats in the treatment groups were daily administered the A. vera gel and ethanolic extract for 9 days. Fasting blood glucose levels and percentage of wound ulcer contraction were measured on day 3, 6, and 9. Statistical Analysis used: The results are expressed as a mean ± Standard Error Mean (SEM. Data were analyzed using one-way analysis of variance (ANOVA after Newman-Keuls test. P < 0.05 were considered statistically significant in all cases. Results: Oral administration of A. vera gel ethanolic extract at a dose of 300 mg/kg body weight per day to diabetic rats for a period of 9 days resulted in a significant reduction in fasting blood glucose and a significant improvement in plasma insulin. Topical application of A. vera gel at a dose 30 mg/kg body weight per day to streptozotocin (STZ-induced diabetic rats for a period of 9 days resulted in no change in blood glucose and plasma insulin. Oral administration as well as topical application of A. vera gel ethanolic extract and gel significantly reduced the blood glucose, improved the plasma insulin, and significantly increased DNA and glycosaminoglycans (GAGs to improve the wound ulcer healing as well as the breaking strength on day 9. Conclusions: Present findings provide a scientific rationale for the use of A. vera gel ethanolic extract, and showed that the gel attenuated the diabetic foot wound in rats.

  6. Investigation of the Peroxovanadate Sol-Gel Process and Characterization of the Gels

    Energy Technology Data Exchange (ETDEWEB)

    Fontenot, Craig Joseph [Iowa State Univ., Ames, IA (United States)

    2001-01-01

    In general, the peroxovanadate solution sol-gel process can be thought of as consisting of two parts: (1) the decomposition of the peroxo species and (2) cation hydrolysis leading to gelation. By controlling the synthesis conditions, both layered and amorphous compounds can be created. However, the type of water coordination observed in these gels was found to be identical no matter what the long-range order. The current work clarified many of the discrepancies found in the literature and offered much new valuable information. Highlights include the types of vanadium environments present at various stages of hydration, the role of adsorbed water, oxygen exchange from adsorbed water into the gel sites, and the ability to create metastable VMoO solid solution phases. These results could have a variety of impacts on future catalysis research.

  7. Sol-gel synthesis of hydroxyapatite; Sintese de hidroxiapatita via sol-gel

    Energy Technology Data Exchange (ETDEWEB)

    Zupanski, M.D.; Lucena, M.P.P.; Bergmann, C.P., E-mail: michelledunin@yahoo.com.b [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil)

    2010-07-01

    Hydroxyapatite (HAp) has been established as the calcium phosphate based compound with most applications in the biological field. Among the numerous techniques for synthesis of HAp, the sol-gel processing route affords great control over purity and formed phases using low processing temperatures. In addition, the sol-gel approach offers an option for homogeneous HAp coating on metal substrates, as well as the ability to generate nanocrystalline powders. In this work, the sol-gel synthesis of HAp was investigated employing triethyl phosphate and calcium nitrate tetrahydrate as phosphorous and calcium precursors, respectively. The aging effect on phase composition and powder morphology of the final product was studied in terms of temperature and aging time. The powders were studied by using X-ray diffraction, Fourier transform infrared spectroscopy, particle size distribution by laser diffraction and scanning electron microscopy. (author)

  8. Species identification of cooked fish by urea isoelectric focusing and sodium dodecylsulfate polyacrylamide gel electrophoresis : a collaborative study

    DEFF Research Database (Denmark)

    Rehbein, H.; Kundiger, R.; Yman, I.M.

    1999-01-01

    of gels to be run in the same flat bed electrophoresis chamber. By strictly following optimised standard operation procedures (SOPs), five unknown cooked samples had to be identified with each technique using a set of 10 raw reference samples. With urea IEF, only one out of 35 identifications......The suitability and reliability of urea IEF and SDS-PAGE for the identification of cooked fish flesh was tested by a collaborative study among nine laboratories. Urea IEF was performed with CleanGels as well as with ImmobilineGels, and ExcelGels were used for SDS-PAGE, enabling all three types...... was incorrect, and with SDS-PAGE a similar result was obtained. It was concluded that methods, as now developed, are suitable for checking the species declaration of fishery products. (C) 1999 Elsevier Science Ltd. All rights reserved...

  9. Extraction Separation of Am(III) and Eu(III) with Thermo-sensitive Gel introducing TPEN Derivatives

    International Nuclear Information System (INIS)

    Kenji Takeshita; Yoshio Nakano; Tatsuro Matsumura; Atsunori Mori

    2008-01-01

    A thermal-swing chromatographic process using a thermo-sensitive gel co-polymerized with NIPA (N-isopropyl-acrylamide) and TPPEN (N,N,N',N'-tetrakis(4-propenyl-oxy-2-pyridyl-methyl)ethylenediamine) was studied for the separation of Am(III) from Eu(III). First, the radiolysis of the TPPEN-NIPA gel was tested by the γ-ray irradiation and the α nuclide adsorption. The extraction separation of Am(III) was not influenced in the radioactive environment of the proposed process. Next, the TPPEN-NIPA gel was immobilized in porous silica particles and the applicability of the gel-immobilized silica to the proposed process was tested. Am(III) was extracted selectively in the gel-immobilized silica at 5 deg. C and the separation factor of Am(III) over Eu(III) was evaluated to be 3.7. The distribution ratio of Am(III) was reduced to less than 1/20 by increasing temperature from 5 deg. C to 40 deg. C. These results indicate that the TPPEN-NIPA gel is applicable to the thermal-swing chromatographic process for the minor actinide recovery. (authors)

  10. PENGARUH GEL EKSTRAK DAUN SIRIH MERAH (Piper crocatum Ruiz & Pav TERHADAP PENYEMBUHAN LUKA BAKAR PADA KELINCI (Oryctolagus cuniculus

    Directory of Open Access Journals (Sweden)

    Fina Ulviani

    2016-10-01

    Full Text Available Research on Gel Formulation of red betel leaf extract (Piper crocatum Ruiz & Pav for the treatment of burn wounds in rabbits (Oryctolagus cuniculus has been conducted. This study aimed to determine variation’s effect of concentration in gel of red betel leaf extract for the treatment of burn wounds in rabbits which had been wounded using hot metal. In this study, the viscous extract was formulated into gel with concentrations of 1%, 2% and 3%. The Gel’s Physical quality evaluation included organoleptic, pH, homogeneity and dispersive ability tests on day 0 until day 28. The gel activity test was performed on 5 rabbits divided into five treatment groups. Each rabbit was burn-wounded using hot metal plate at diameter of 20 mm. Each group was given five wounds consisting of a negative control, 1%, 2%, 3% of extract formula and a positive control. The diameter measurement of the wounds was done on the 1st, 3rd, 5th, 7th, 9th and the 21st day. Data of wound healing percentage was statistically analyzed with Two-Way ANOVA. The results showed that the gel with 3% of red betel leaf extract of which percentage of healing as much as 85.81% compared to gel extract 1% and 2% with percentage 65,32% dan 76,58%.

  11. Haptic characterization of human skin in vivo in response to shower gels using a magnetic levitation device.

    Science.gov (United States)

    Yardley, R; Fan, A; Masters, J; Mascaro, S

    2016-02-01

    Skin products such as shower gels have a direct impact on skin health and wellness. Although qualitative haptic characterization through explicit, verbal measures in consumer studies are often sufficient for general comparison on consumer perceived skin feel, a quantitative approach is desired to characterize minute changes in skin condition in response to various skin products. Prior research has sought to characterize the haptic properties of human skin in vitro and in vivo, but very few studies have compared the haptic effects of commercial skin products having relatively similar formulations. In addition, related studies have typically utilized simple, low-precision devices and fixtures. The purpose of this study was to use a precision magnetic levitation haptic device to characterize the frictional properties of human skin in vivo before, during, and after treatment with commercially available shower gels, to capture the entire cycle of consumer experience on skin feel. A hybrid force-position control algorithm was used to control a precision magnetic levitation haptic device with silicone tactor to stroke the human skin (on the volar forearm) in vivo. Position and force data were collected from 32 human subjects using eight different commercially available shower gels, while stroking the skin before, during, and after treatment. The data were analyzed to produce coefficients of friction and viscous damping constant, which were used as metrics for comparing the effects of each shower gel type. Other factors investigated include skin test location, order, and subject age and gender. Results showed significant differences between the effects of eight various shower gels, especially after accounting for variance between subjects. Most notably, Shower Gel four with high level of petrolatum, along with Shower Gels five and six with low levels of castoryl maleate (a skin lipid analog), as well as Shower Gel two with high levels of vegetable oils yielded higher skin

  12. Investigation of Sol-Gel coatings exposed in the condenser at Fynsvaerket. Part 1

    Energy Technology Data Exchange (ETDEWEB)

    Montgomery, M. [DTU Management Engineering, Kgs. Lyngby (Denmark); Vilhelmsen, T. [Vattenfall Heat Nordic, Copenhagen (Denmark)

    2007-10-15

    The Danish Technological Institute (DTI) has developed a coatings technique using Hybrid Sol-gel nanotechnology to produce coatings which can change the surface characteristics of various components. It is the purpose of this project to investigate where such coatings can be utilised in the power generating industry with respect to fouling and corrosion resistance. Four different sol-gel coatings have been applied to brass condenser tubes about 10 cm in length. The coatings are termed 23, 35, 38, 46. The exact composition of these different coatings was not given. These sections were mounted in the water chamber inlet before the tubes into the condenser and another set were placed on the condenser plate at the outlet. The condenser tube has a composition 76 wt.% Cu, 22 wt.% Zn and 2 wt.% Al corresponding to an aluminium brass. Based on the visual appearance of the four coatings it is clear that Sol-gel 38 does not reduced biological fouling and rust spots can be clearly seen on Sol-gel 46. Thus based on visual appearance, sol-gel 23 and sol-gel 35 are most promising. Due to the presence of corrosion products on the inner side of the unexposed tubes which influences the adherence and protectiveness of coatings applied, the inner side cannot be used to assess the coatings performance. In the next exposure test, better initial cleaning of the tubes is required. Based on visual assessment, Sol-gel 38 has not solved the problems with biological fouling compared to the other coatings. With respect to corrosion, it is observed that in all cases there are corrosion products, either chlorides or oxides/hydroxides/carbonates, present in the interface between the tube and the coating. Coating 38 also experienced lack of adhesion. This could be triggered by a build up of corrosion products under the coating which would eventually lead to delaminating of the coating. Whether the corrosion rate has been decreased compared to the uncoated tubes is not known, however in the next

  13. ANALISA DAYA SERAP SILIKA GEL BERBAHAN DASAR ABU SEKAM PADI

    Directory of Open Access Journals (Sweden)

    Hendriwan Fahmi

    2016-08-01

    Full Text Available Rice husk ash Silica Gel is aproduct which call be used in preventing the humidity by absorbing the water ion on the water andonthe air. This absorbing isbased onthe size, the composition and the total amount ofpolluter which contained on the Silica Gel. The purpose of making this silica gel is to seehow much thiskind of Silica Gel can absorb and compare it to the synthetic one,and also processing rise husk ashto be something useful, Ion water can be absorbed much more by using this natural silica gel if it is compared to the synthetic silica gel. This is because of its capable inabsorbing more –OHand O from water and air. Afterdoing a research with column method, silica gel was beingput in 50 ml water. Fromthis research, natural silica can absorb much more water (0.0010 gr/ml, 0.285 % water level ofweigh in comparing with synthetic one (0.008gr/ml with 0.248 %water level ofweight andsintering (0,007 gr/ml 0.253%water level and non-sintering silica gel contains 39.22 % weight of silica, 30.93 %weight of sintering silica gel, and 33.40 % of the synthetic. More silica and water level, means more total amount of absorbing. This silica gel application is considered with capability ofabsorbing andthe level of the water.

  14. Photo-induced locomotion of chemo-responsive polymer gels

    Science.gov (United States)

    Dayal, Pratyush; Kuksenok, Olga; Balazs, Anna C.

    2009-03-01

    The need to translate chemical energy into a mechanical response, a characteristic of many biological processes, has motivated the study of stimuli-responsive polymer gels. Recently, it has been shown experimentally that by coupling the mechanical properties of the gel with the Belousov-Zhabotinsky (BZ) reaction it is possible to induce self-sustained oscillations in the gel. One of the means for controlling these chemical oscillations is using light as an external stimulus. To study the effect of light on the mechanical behavior of the gel, we use our recently developed a 3D gel lattice spring model (gLSM) which couples the BZ reaction kinetics to the gel dynamics. In this model, the polymer-solvent interactions were taken into account by adding a coupling term to the Flory-Huggins free energy. By virtue of this coupling term, the swelling---de-swelling behavior of the gel was captured in 3D. In order to include the effect of the polymer on the reaction kinetics, the Oregonator model for the photo-sensitive BZ reaction was also modified. Using gLSM model, we probed the effect of non-uniform light irradiation on the gel dynamics. We were able to manipulate the direction and velocity of locomotion of the gel using light as a control parameter. This ability to control the movement of the gel can be utilized in a variety of applications, ranging from bio-actuators to controlled drug release systems.

  15. A novel energy absorber based on magnetorheological gel

    Science.gov (United States)

    Pang, Haoming; Xuan, Shouhu; Sun, Chuanlin; Gong, Xinglong

    2017-10-01

    In this work, a novel magnetorheological energy absorber (MREA) was designed by using magnetorheological gel (MRG) as the damping medium. The proposed MREA had tunable piston gap distances and variable inner magnetic flux density distribution. The piston gap distance could be varied from 7-2 mm and the magnetic flux density at the gap increased from 120-860 mT, respectively. Under both low velocity compression and high speed impact, the damping could be divided into three parts. In the impact test, the velocity of a drop hammer could be reduced from to 3.4-0 m s-1 within a very short time (13 ms) and distance (17 mm). The maximum damping force of the MREA reached to as high as 8 kN. The damping force could also be adjusted by changing the current input. Under a 2 A current, the energy absorption ratio increased about 23% (from 4.13-5.07 J mm-1).

  16. Bioorganically doped sol-gel materials containing amyloglucosidase activity

    Directory of Open Access Journals (Sweden)

    Vlad-Oros Beatrice

    2006-01-01

    Full Text Available Amyloglucosidase (AMG from Aspergillus niger was encapsulated in various matrices derived from tetraethoxysilane, methyltriethoxysilane, phenyltriethoxysilane and vinyltriacetoxysilane by different methods of immobilization. The immobilized enzyme was prepared by entrapment in two steps, in one-step and entrapment/deposition, respectively. The activities of the immobilized AMG were assayed and compared with that of the native enzyme. The effects of the organosilaneprecursors and their molar ratios, the immobilization method, the inorganic support (white ceramic, red ceramic, purolite, alumina, TiO2, celite, zeolite and enzyme loading upon the immobilized enzyme activity were tested. The efficiency of the sol-gel biocomposites can be improved through combination of the fundamental immobilization techniques and selection of the precursors.

  17. Safety and Pharmacokinetics of Once-Daily Dapsone Gel, 7.5% in Patients With Moderate Acne Vulgaris.

    Science.gov (United States)

    Jarratt, Michael T; Jones, Terry M; Chang-Lin, Joan-En; Tong, Warren; Berk, David R; Lin, Vince; Kaoukhov, Alexandre

    2016-10-01

    Reducing the dosing frequency of topical acne treatments to once daily may improve adherence. Evaluate pharmacokinetics (PK), safety, and tolerability of 3 formulations of once-daily dapsone gel, 7.5% and of twice-daily dapsone gel, 5% over 28 days in patients with moderate acne vulgaris. This phase 1, multicenter, parallel-group study randomized males and females aged 16 to 35 years to 1 of 3 dapsone gel, 7.5% formulations (DAP-11078, DAP-11079, or DAP-11080 double-blind; applied once daily) or to dapsone gel, 5% (investigator-blinded only, applied twice-daily). Blood samples were collected for PK assessments of dapsone and its metabolites, N-acetyl dapsone (NAD) and dapsone hydroxylamine (DHA), before the morning dose on days 1, 7, 14, 18, 21, 26, 27, and 28, and at several follow-up time points (days 29-32). Safety profile assessments included adverse events (AEs), physical examinations, laboratory tests, and local tolerability assessments. Steady-state dapsone, NAD, and DHA concentrations were reached within 7 days of the first dose in all treatment groups. Daily systemic exposures of the 3 dapsone gel, 7.5% formulations were approximately 25% to 40% lower than that for dapsone gel, 5%, and these differences were statistically significant. Among the 3 dapsone gel, 7.5% formulations, the highest daily exposure of dapsone (per the AUC) was observed with DAP-11080, with respective Cmax and AUC0-24 being approximately 28.6% and 28.7% lower relative to dapsone gel, 5%. Most AEs were mild to moderate in intensity. The safety profiles for all 3 formulations of once-daily dapsone, 7.5% gel and twice-daily dapsone gel, 5% were similar following 28 days of topical administration. All 4 dapsone formulations were well tolerated. This study demonstrated lower systemic exposure with all 3 once-daily dapsone gel, 7.5% formulations than with twice-daily dapsone gel, 5%. All 4 formulations were well tolerated and demonstrated similar safety profiles. J Drugs Dermatol. 2016;15(10):1250-1259.

  18. RNA purification by preparative polyacrylamide gel electrophoresis.

    Science.gov (United States)

    Petrov, Alexey; Wu, Tinghe; Puglisi, Elisabetta Viani; Puglisi, Joseph D

    2013-01-01

    Preparative polyacrylamide gel electrophoresis (PAGE) is a powerful tool for purifying RNA samples. Denaturing PAGE allows separation of nucleic acids that differ by a single nucleotide in length. It is commonly used to separate and purify RNA species after in vitro transcription, to purify naturally occurring RNA variants such as tRNAs, to remove degradation products, and to purify labeled RNA species. To preserve RNA integrity following purification, RNA is usually visualized by UV shadowing or stained with ethidium bromide or SYBR green dyes. © 2013 Elsevier Inc. All rights reserved.

  19. Industrial applications of sol-gel technology

    International Nuclear Information System (INIS)

    Tuloch, S.M.; Tulloch, G.E.

    1995-01-01

    The purpose of this paper has been to provide a broad, rather than comprehensive view. We have presented a range of applications and only a selection of involved companies and researchers and have relied to a large extent on published information. Nevertheless, we are sure that our view of the importance of Sol-gel technology as an emerging technology, with enormous impact across a wide range of manufacturing, is demonstrated. Applications which are either in production or have been foreshadowed include four broad categories: coatings, fibres, powders and monoliths

  20. Investigation into response characteristics of the chitosan gel artificial muscle

    Science.gov (United States)

    Zhao, Gang; Yang, Junjie; Wang, Yujian; Zhao, Honghao; Fu, Yu; Zhang, Guangli; Yu, Shuqin; Wu, Yuda; Wei, Chengye; Liu, Xuxiong; Wang, Zhijie

    2018-01-01

    Bionic artificial muscle made from chitosan gel is an emerging type of the ionic electro active polymer with advantages of large deformation, low cost and environmental protection etc, which leads to a research focus and wide application in the fields of bionic engineering and intelligence material recently. In this paper, effects and improvement mechanisms of the direct casting and genipin cross-linking processes on response speed properties of the chitosan gel artificial muscle (CGAM) were mainly studied. Based on in-depth analysis of the CGAM response mechanism, a platform was built for testing the response performance of the CGAM, then its equivalent circuit and mathematical models were also established. Furthermore, control experiments were carried out to test and analyze several performances of the CGAM on response speed, electrical conductivity, mechanical properties and microstructure with different control variables. The experimental results illustrated that the CGAM assembled by direct casting enabled its electric actuating membrane and non-metallic electrode membrane tightly attached together with low contact resistance, which dramatically promoted the electrical conductivity of the CGAM resulting in nearly doubled response speed. Besides, different concentrations of genipin were adopted to cross-link the CGAM actuating membranes, and then it was found that the response speed of the uncross-linked CGAM was fast in the initial stage, but as time increased, it declined rapidly with poor steadiness. While there was no obvious decrease over time on the response speed of the CGAM cross-linked with low genipin concentration. Namely, its stability was getting better and better. In addition, the response speed of the CGAM cross-linked with low concentration of genipin was roughly the same as uncross-linked CGAM, which was quicker than that of high concentration. In this work, its internal mechanisms, feasible assembly technique and green modification method were

  1. In vitro activity of Aloe vera inner gel against Helicobacter pylori strains.

    Science.gov (United States)

    Cellini, L; Di Bartolomeo, S; Di Campli, E; Genovese, S; Locatelli, M; Di Giulio, M

    2014-07-01

    Aloe barbadensis Miller (Aloe vera) is a herbal remedy widely used for a variety of illnesses; A. vera leaf extracts have been promoted for detoxification, cure constipation, help flush out toxins and wastes from the body, promote digestion and are used in the treatment of peptic ulcer for cytoprotective action. The aim of this study was to evaluate the antibacterial activity of A. vera inner gel against both susceptible and resistant Helicobacter pylori strains isolated in Abruzzo region, Italy. The inner gel of leaves of a 5-year-old plant of A. vera was extracted, homogenized and tested from 800 to 1.56 mg ml(-1) against 14 clinical strains and one reference strain of H. pylori using the broth microdilution methodology. Furthermore, the sample of A. vera was investigated for the chemical fingerprint of anthraquinones. The inhibitory concentrations of A. vera inner gel were similar to the bactericidal ones, with values ranging from 6.25 to 800 mg ml(-1) . Fifty per cent of the detected strains, independently of their susceptibility profile, were inhibited in their growth at 100 mg ml(-1) . Aloe vera inner gel expresses antibacterial properties against H. pylori and, therefore, in combination with antibiotics, could represent a novel strategy for the treatment of the infection of H. pylori, especially in cases of multiresistance. The study demonstrates that the Aloe vera inner gel expresses antibacterial properties against both susceptible and resistant Helicobacter pylori strains. These findings may impact on the antimicrobial resistance phenomenon of H. pylori, proposing the A. vera inner gel as a novel effective natural agent for combination with antibiotics for the treatment of H. pylori gastric infection. © 2014 The Society for Applied Microbiology.

  2. Effects of a Pseudophysiological Environment on the Elastic and Viscoelastic Properties of Collagen Gels

    Directory of Open Access Journals (Sweden)

    Sébastien Meghezi

    2012-01-01

    Full Text Available Vascular tissue engineering focuses on the replacement of diseased small-diameter blood vessels with a diameter less than 6 mm for which adequate substitutes still do not exist. One approach to vascular tissue engineering is to culture vascular cells on a scaffold in a bioreactor. The bioreactor establishes pseudophysiological conditions for culture (medium culture, 37°C, mechanical stimulation. Collagen gels are widely used as scaffolds for tissue regeneration due to their biological properties; however, they exhibit low mechanical properties. Mechanical characterization of these scaffolds requires establishing the conditions of testing in regard to the conditions set in the bioreactor. The effects of different parameters used during mechanical testing on the collagen gels were evaluated in terms of mechanical and viscoelastic properties. Thus, a factorial experiment was adopted, and three relevant factors were considered: temperature (23°C or 37°C, hydration (aqueous saline solution or air, and mechanical preconditioning (with or without. Statistical analyses showed significant effects of these factors on the mechanical properties which were assessed by tensile tests as well as stress relaxation tests. The last tests provide a more consistent understanding of the gels' viscoelastic properties. Therefore, performing mechanical analyses on hydrogels requires setting an adequate environment in terms of temperature and aqueous saline solution as well as choosing the adequate test.

  3. PEMBUATAN DAN UJI AKTIVITAS SEDIAAN GEL SCARLESS WOUND DENGAN EKSTRAK BINAHONG DAN ZAT AKTIF PIROXICAM

    Directory of Open Access Journals (Sweden)

    Ayaga Divadi

    2016-06-01

    Full Text Available Wound is a condition where the tissue integrity is damaged so that body will attempt to repair the damaged tissue by wound healing mechanism. This mechanism usually results in the scar formed by its inflammatory phase. Binahong (Anredera cordifolia (Ten. Steenis contains ascorbic acid and flavonoids which are important for collagen formation, to improve the rate of the wound healing process. Piroxicam can shorten or detain the inflammatory phase by inhibiting the cyclooxygenase (COX enzymes in the prostaglandine synthesis process, which play an important role in scar formation. The aim of this research is to discover if the combination of piroxicam and binahong extract in the scarless wound gel could offer scar reduction effect. In this research, a gel preparation with binahong extract was combined with piroxicam to develop the scarless wound gel (BinPirox. The research was purely experimental. It was done by conducting a histopathological test followed by collagen area calculation. The data were analyzed by independent sample t-test with 95% significancy level. In this research, the addition of piroxicam was expected to reduce the scar formation on incisional wound of white Swiss Webster mice (Mus musculus. The result showed that BinPirox formed statistically less scar when compared to Bin (a gel preparation with binahong extract.

  4. Influence of whitening gel on pulp chamber temperature rise by in-office bleaching technique

    Directory of Open Access Journals (Sweden)

    Sandro Cordeiro Loretto

    Full Text Available INTRODUCTION: Dental bleaching is a conservative method for the aesthetic restoration of stained teeth. However, whitening treatments are likely to cause adverse effects when not well planned and executed. OBJECTIVE: This study evaluated the influence of whitening gel on temperature rise in the pulp chamber, using the in-office photoactivated dental bleaching technique. MATERIAL AND METHOD: The root portion of an upper central human incisor was sectioned 3mm below the cemento-enamel junction. The root canal was enlarged to permit the insertion of the K-type thermocouple sensor (MT-401 into the pulp chamber, which was filled with thermal paste to facilitate the transfer of heat during bleaching. Three photosensitive whitening agents (35% hydrogen peroxide were used: Whiteness HP (FGM, Whiteness HP Maxx (FGM and Lase Peroxide Sensy (DMC. An LED photocuring light (Flash Lite - Discus Dental was used to activate the whitening gels. Six bleaching cycles were performed on each group tested. The results were submitted to one-way ANOVA and LSD t-test (α<0.05. RESULT: The lowest mean temperature variation (ºC was detected for Lase Peroxide Sensy (0.20, while the highest was recorded for Whiteness HP (1.50. CONCLUSION: The Whiteness HP and Whiteness HP Maxx whitening gels significantly affected the temperature rise in the pulp chamber during bleaching, and this variation was dependent on the type of whitening gel used.

  5. Cumulative irritation potential of metronidazole gel compared to azelaic acid gel after repeated applications to healthy skin.

    Science.gov (United States)

    Ziel, Kristin; Yelverton, Christopher B; Balkrishnan, Rajesh; Feldman, Steven R

    2005-01-01

    Metronidazole 0.75% gel and azelaic acid 15% gel are commonly used to treat rosacea. Irritation is a common side effect. To assess the cumulative irritation potential of metronidazole 0.75% gel and azelaic acid 15% gel. Metronidazole 0.75% gel, azelaic acid 15% gel, and a white petrolatum negative control were applied under occlusive conditions to the upper back of a total of 33 healthy subjects. There were twelve 24-hour applications (4 times a week) and three 72-hour applications on weekends during a 3-week period. Skin reactions (erythema score +/- other local reaction) were assessed within 15 to 30 minutes of removal of the products. The mean cumulative irritancy index of metronidazole 0.75% gel was significantly lower than that of azelaic acid 15% gel and not significantly higher than the negative control product. There was increasing cumulative irritancy with azelaic acid; no cumulative irritancy was seen for either metronidazole or white petrolatum. Metronidazole 0.75% gel is less irritating in sustained use than azelaic acid 15% gel.

  6. EFEKTIVITAS GEL ANTIJERAWAT EKSTRAK METANOL DAUN PACAR AIR (Impatiens balsamina L. TERHADAP BAKTERI Propionibacterium acnes dan Staphylococcus epidermidis SECARA IN VITRO

    Directory of Open Access Journals (Sweden)

    Septira Murtiningsih

    2014-06-01

    Full Text Available Propionibacterium acnes dan Staphylococcus epidermidis is an inflamation triggering bacterias in acne vulgaris. Plants that has been studied for antibacterial effect is Impatiens balsamina. Gel bases for acnes therapy are hydrophilic bases like HPMC (Hydroxypropyl methylcellulose and carbopol. The aim of this study was to know the optimum combination of Carbopol and HPMC (Hydroxypropyl metylcellulose in gel formulation that gives best antibacterial effect and to evaluate physical and chemical properties of gel. Extraction was performed by soxhlet method with methanol as solvent. The design of optimum gel formulation was performed using simplex lattice design. Optimum gel formulation was combination of 21% HPMC and 79% Carbopol. Verification results showed that optimum gel of inhibition zone of P. acnes and S. epidermidis is 17.61±0.93 mm and 16.01±1.01 mm respectively. Positive control compared to optimum gel showed inhibition zone toward P.acnes and S.epidermidis of 29.1±1.34 mm and 24.98±1.83 mm respectively. Analysis results using T-test showed that p-value was lower than 0.05 (p<0.05 hence the effectivity from optimum gel was significantly different from positive control that has greater activity than optimum gel. Evaluation of optimum gel showed gel has dark brown color, specific odor from extract, adhesive force of 3.17 minutes, spreadibility of 32.69 cm2, viscosity of 436.66 cP and as well as the pH of 5.23. Keywords: Methanolic extracts of Impatiens balsamina leaves, Propionibacterium acnes, Staphylococcus epidermidis, gel, carbopol, HPMC   ABSTRAK Propionibacterium acnes dan Staphylococcus epidermidis adalah bakteri pemicu peradangan pada jerawat. Tanaman yang telah banyak diteliti sebagai antibakteri adalah pacar air (Impatiens balsamina L.. Bahan dasar gel yang cocok untuk terapi jerawat adalah bahan dasar hidrofilik seperti HPMC (Hydroxypropyl methylcellulose dan karbopol. Tujuan dari penelitian ini adalah untuk mengetahui

  7. Investigating potential physicochemical errors in polymer gel dosimeters

    International Nuclear Information System (INIS)

    Sedaghat, Mahbod; Lepage, Martin; Bujold, Rachel

    2011-01-01

    Measurement errors in polymer gel dosimetry can originate either during irradiation or scanning. One concern related to the exothermic nature of polymerization reaction was that the heat released in polymer gel dosimeters during irradiation modifies their dose response. In this paper, the effect of heat released from the exothermal polymerization reaction on the dose response of a number of dosimeters was studied. In addition, we investigated whether heat-generated geometric distortion existed in newly proposed gel dosimeters that contain highly thermoresponsive polymers. Our results suggest that despite a significant internal temperature increase in some gel compositions, their dose responses are not affected when oxygen is well expelled mechanically from the gel mixture. We also report on significant pre-irradiation instability in some recently developed polymer gel dosimeters but that geometric distortions were not observed. Data obtained by a set of small calibration vials are compared to those obtained from larger phantoms, and potential physicochemical causes of deviations between them are identified.

  8. Explorative data analysis of two-dimensional electrophoresis gels

    DEFF Research Database (Denmark)

    Schultz, J.; Gottlieb, D.M.; Petersen, Marianne Kjerstine

    2004-01-01

    Methods for classification of two-dimensional (2-DE) electrophoresis gels based on multivariate data analysis are demonstrated. Two-dimensional gels of ten wheat varieties are analyzed and it is demonstrated how to classify the wheat varieties in two qualities and a method for initial screening...... of gels is presented. First, an approach is demonstrated in which no prior knowledge of the separated proteins is used. Alignment of the gels followed by a simple transformation of data makes it possible to analyze the gels in an automated explorative manner by principal component analysis, to determine...... if the gels should be further analyzed. A more detailed approach is done by analyzing spot volume lists by principal components analysis and partial least square regression. The use of spot volume data offers a mean to investigate the spot pattern and link the classified protein patterns to distinct spots...

  9. Non-stationary heat transfer in gels applied to biotehnology

    Directory of Open Access Journals (Sweden)

    Pokusaev Boris

    2017-01-01

    Full Text Available Unsteady heat transfer in agarose gels of various concentrations was studied in order to make a breakthrough in the technology of 3-D additive bioprinting. Data on the kinetics of the phase transformation was obtained using spectroscopy as a function of temperature during the formation of agarose hydrogel. The dynamics of aging was investigated for gels of different densities. The time dependence of the structural changes was obtained. Particular attention was paid to the changes in the structure of the gel due to the processes of evaporation of the liquid during the gel formation and during long-term storage. Experiments were performed to determine the dynamics of the temperature fields simultaneously with heat flux measurements during the formation of agarose gels from different initial concentrations. A technique based on experimental data for the computations of the thermophysical coefficients of agarose gels was developed.

  10. A simple gel electrophoresis method for separating polyhedral gold nanoparticles

    Science.gov (United States)

    Kim, Suhee; Lee, Hye Jin

    2015-07-01

    In this paper, a simple approach to separate differently shaped and sized polyhedral gold nanoparticles (NPs) within colloidal solutions via gel electrophoresis is described. Gel running parameters for separating efficiently gold NPs including gel composition, added surfactant types and applied voltage were investigated. The plasmonic properties and physical structure of the separated NPs extracted from the gel matrix were then investigated using transmission electron microscopy (TEM) and UV-vis spectrophotometry respectively. Data analysis revealed that gel electrophoresis conditions of a 1.5 % agarose gel with 0.1 % sodium dodecyl sulfate (SDS) surfactant under an applied voltage of 100 V resulted in the selective isolation of ~ 50 nm polyhedral shaped gold nanoparticles. Further efforts are underway to apply the method to purify biomolecule-conjugated polyhedral Au NPs that can be readily used for NP-enhanced biosensing platforms.

  11. Supramolecular gel electrophoresis of large DNA fragments.

    Science.gov (United States)

    Tazawa, Shohei; Kobayashi, Kazuhiro; Oyoshi, Takanori; Yamanaka, Masamichi

    2017-10-01

    Pulsed-field gel electrophoresis is a frequent technique used to separate exceptionally large DNA fragments. In a typical continuous field electrophoresis, it is challenging to separate DNA fragments larger than 20 kbp because they migrate at a comparable rate. To overcome this challenge, it is necessary to develop a novel matrix for the electrophoresis. Here, we describe the electrophoresis of large DNA fragments up to 166 kbp using a supramolecular gel matrix and a typical continuous field electrophoresis system. C 3 -symmetric tris-urea self-assembled into a supramolecular hydrogel in tris-boric acid-EDTA buffer, a typical buffer for DNA electrophoresis, and the supramolecular hydrogel was used as a matrix for electrophoresis to separate large DNA fragments. Three types of DNA marker, the λ-Hind III digest (2 to 23 kbp), Lambda DNA-Mono Cut Mix (10 to 49 kbp), and Marker 7 GT (10 to 165 kbp), were analyzed in this study. Large DNA fragments of greater than 100 kbp showed distinct mobility using a typical continuous field electrophoresis system. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Sol-gel precursors and products thereof

    Science.gov (United States)

    Warren, Scott C.; DiSalvo, Jr., Francis J.; Weisner, Ulrich B.

    2017-02-14

    The present invention provides a generalizable single-source sol-gel precursor capable of introducing a wide range of functionalities to metal oxides such as silica. The sol-gel precursor facilitates a one-molecule, one-step approach to the synthesis of metal-silica hybrids with combinations of biological, catalytic, magnetic, and optical functionalities. The single-source precursor also provides a flexible route for simultaneously incorporating functional species of many different types. The ligands employed for functionalizing the metal oxides are derived from a library of amino acids, hydroxy acids, or peptides and a silicon alkoxide, allowing many biological functionalities to be built into silica hybrids. The ligands can coordinate with a wide range of metals via a carboxylic acid, thereby allowing direct incorporation of inorganic functionalities from across the periodic table. Using the single-source precursor a wide range of functionalized nanostructures such as monolith structures, mesostructures, multiple metal gradient mesostructures and Stober-type nanoparticles can be synthesized. ##STR00001##

  13. A novel quantification method for low-density gel dosimeter.

    Science.gov (United States)

    Nedaie, Hasan Ali; Pak, Farideh; Vaezzadeh, Vahid; Eqlimi, Ehsan; Takavar, Abas; Saligheh Rad, Hamid Reza; Mosleh Shirazi, Mohammad Amin; Mirheydari, Mona

    2018-01-01

    Low signal-to-noise ratio (SNR) images of lung-like (low-density [LD]) gel dosimeters, compared to unit-density (UD) gels, necessitate the use of different quantification methods. In this study, a new method is introduced based on noise correction and exponential (NCEXP) fitting. The feasibility of NCEXP method for quantifying dose absorption in LD gels is evaluated. Sensitivity, dose resolution, detectable dynamic range, and correlation of the calibration curve for both UD and LD gel dosimeters are the parameters, which we analyze to investigate the consequences of new method. Results of NCEXP method are compared to maximum likelihood estimation of rician distribution (MLE-R) and variable echo number (VAREC) quantification methods. Dose response of LD gel dosimeter shows wider detectable dynamic range as compared to UD gel. Using NCEXP method for both LD and UD dosimeter gels, a more sensitive calibration curve with a superior dose resolution is obtained. The advantage of new quantification method is more significant for LD dosimeter gel analysis, where SNR decreases as a result of higher absorbed doses (≥10 Gy). Despite the inverse effect of the VAREC method on detectable dose range of UD gel, no specific changes are observed in dynamic dose range of LD gel dosimeter with different quantification methods. The correlations obtained with different methods were approximately of the same order for UD and LD gels. NCEXP method seems to be more effective than the MLE-R and VAREC methods for quantification of LD dosimeter gel, especially where high-dose absorption and steep-dose gradients exist such as those in intensity-modulated radiation therapy and stereotactic radiosurgery.

  14. Purification of radiolabeled RNA products using denaturing gel electrophoresis

    OpenAIRE

    Adachi, Hironori; Yu, Yi-Tao

    2014-01-01

    This unit discusses a basic method for purification of radiolabeled RNAs using denaturing polyacrylamide gel electrophoresis. The method consists of a number of experimental procedures, including total RNA preparation from yeast cells, isolation of a specific RNA from total yeast RNA, RNA 3' terminal labeling using nucleotide (5’[32P]pCp) addition (via ligation), denaturing (8 M urea) polyacrylamide gel electrophoresis, and RNA extraction from the gel slice. Key points for achieving good elec...

  15. Prenatal Virilization Associated with Paternal Testosterone Gel Therapy

    OpenAIRE

    Rivkees ScottA; Patel Anisha

    2010-01-01

    Transdermal testosterone gels are used in the treatment of hypoandrogenism of males. Virilization due to exposure to testosterone gels has been reported in children resulting in a US Food and Drug Administration (FDA) warning about secondary exposure to these products. At present, we are unaware of prenatal virilization associated with unintentional testosterone gel exposure. We report prenatal virilization in a female infant due to secondary maternal exposure to the father's testosterone ge...

  16. Formulation and evaluation of antipsoriatic gel using natural excipients

    OpenAIRE

    Raghupatruni Jhansi Laxmi; R. Karthikeyan; P. Srinivasa Babu; R.V.V. Narendra Babu

    2013-01-01

    Objective: To develop topical gel formulations of Psoralen using natural excipients to minimize the side effects of synthetic drugs. Methods: The Psoralen gel formulations were prepared using different natural gums and polymers. The physicochemical compatibility between Psoralen and other excipients was confirmed by using Fourier transform infrared spectroscopy. All prepared gel formulations were evaluated for drug content uniformity, viscosity, pH, and stability. The release of psoralen f...

  17. Capillary gel electrophoresis for rapid, high resolution DNA sequencing.

    OpenAIRE

    Swerdlow, H; Gesteland, R

    1990-01-01

    Capillary gel electrophoresis has been demonstrated for the separation and detection of DNA sequencing samples. Enzymatic dideoxy nucleotide chain termination was employed, using fluorescently tagged oligonucleotide primers and laser based on-column detection (limit of detection is 6,000 molecules per peak). Capillary gel separations were shown to be three times faster, with better resolution (2.4 x), and higher separation efficiency (5.4 x) than a conventional automated slab gel DNA sequenci...

  18. Pelepasan Ibuprofen Dari Gel Karbomer 940 Kokristal Ibuprofen-Nikotinamida

    OpenAIRE

    Agustin, Rini; Sari, Novica; Zaini, Erizal

    2014-01-01

    Salah satu metode untuk meningkatkan kelarutan adalah co-kristalisasi. Ibuprofen dapat digunakan dalam aplikasi topikal untuk rheumatoid arthrisi, sehingga telah dilakukan sebuah studi tentang formulasi dan pelepasan kokristal ibuprofen-nikotinamida dari gel karbomer 940. Kokristal diperoleh dari metode penguapan pelarut dengan komposisi equimol (1:1). Gel terdiri dari dua formula dengan jumlah ibuprofen yang sama (5%). Formula pertama adalah gel kokristal ibuprofen-nicotinamida dan Formula d...

  19. Preoperative povidone-iodine vaginal gel in abdominal hysterectomy: a randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Beigi A

    2007-09-01

    Full Text Available Background: Infectious complications of hysterectomy remain common despite the use of antibiotic. The usual existing methods of preoperative antisepsis do not control the vaginal bacteria that are the primary cause of contamination at the surgical site. Our goal was to assess whether febrile morbidity after total abdominal hysterectomy is decreased by the addition of povidone-iodine gel at the vaginal apex after the routine vaginal preparation with povidone-iodine solution.Methods: We carried out a prospective randomized trial on women admitted for elective abdominal hysterectomy. Inclusion criteria included planned abdominal hysterectomy for benign or malignant gynecologic conditions. Exclusion criteria consisted of emergency surgery, current treatment for pelvic infection, and known povidone-iodine allergy. A total of 168 patients were randomized to either the control group or the intervention group, who received 20 cc povidone-iodine gel placed at the vaginal apex immediately before the operation. Both groups received the routine preoperative preparation of antimicrobial prophylaxis, abdominal and vaginal scrubbing with povidone-iodine solution prior to the operation. The primary outcome was post-operative febrile morbidity. Other outcomes included abdominal wound infection, vaginal cuff cellulitis or pelvic abscess. Data was analyzed using Fisher's exact test. p<0.05 was considered statistically significant.Results: The overall rate of febrile morbidity was 20.5%. Febrile morbidity occurred in ten of 80 (12.5% women receiving the povidone-iodine gel preparation and 24 of 86 (27.9% women not receiving the gel (p<0.05. The rate of abdominal wound infection was 18.6% (16 in the control group, and 5% (4 in the gel group (p<0.05. Vaginal cuff cellulitis was seen in three patients from the control group versus one woman from the gel group (p>0.05. Pelvic abscess was diagnosed in one patient from the control group and in no patients from the

  20. Physical and radiological properties of radiochromic gel as of its composition

    Science.gov (United States)

    Lee, Sang Hoon; Kim, Juree; Shim, Su Jung; Chang, Kyung Hwan; Lim, Sangwook; Huh, Hyun Do; Shin, Dong Oh; Cho, Sam Ju

    2014-04-01

    high-dose group. Moreover, we observed that the absorbance between 24 and 48 h after irradiation increased by approximately 5% at 5 Gy. For gel groups tested at high doses, the aging effect was reduced by approximately 1%.

  1. Silica scintillating materials prepared by sol-gel methods

    International Nuclear Information System (INIS)

    Werst, D.W.; Sauer, M.C. Jr.; Cromack, K.R.; Lin, Y.; Tartakovsky, E.A.; Trifunac, A.D.

    1993-01-01

    Silica was investigated as a rad-hard alternative to organic polymer hosts for organic scintillators. Silica sol-gels were prepared by hydrolysis of tetramethoxysilane in alcohol solutions. organic dyes were incorporated into the gels by dissolving in methanol at the sol stage of gel formation. The silica sol-gel matrix is very rad-hard. The radiation stability of silica scintillators prepared by this method is dye-limited. Transient radioluminescence was measured following excitation with 30 ps pulses of 20 MeV electrons

  2. Inclusion type radiochromic gel dosimeter for threedimensional dose verification

    Science.gov (United States)

    Usui, Shuji; Yoshioka, Munenori; Hayashi, Shin-ichiro; Tominaga, Takahiro

    2015-01-01

    For the verification of 3D dose distributions in modern radiation therapy, a new inclusion type radiochromic gel detector has been developed. In this gel, a hydrophobic leuco dye (leucomalachite green: LMG) was dissolved in water as an inclusion complex with highly branched cyclic dextrin. The radiation induced radical oxidation property of the LMG gel with various sensitizers was investigated. As a result, the optical dose responses were enhanced by the addition of bromoacetic acid and manganese (II) chloride. Unfavorable auto-oxidation of the gel was reduced when it was stored at 4°C.

  3. Application of CMPO containing gels to metal extraction

    International Nuclear Information System (INIS)

    Dozol, J.F.; Brunette, J.P.

    1990-01-01

    Immersed in solubility-consistent organic solvents, high polymers can swell and form gels. Choosing the organic solvent among metal extracting solvents, metal extracting gels can be prepared. The advantages of the liquid-gel extraction process, in comparison with the liquid-liquid one, are to allow the extraction of metal cations from diluted aqueous solutions by using high aqueous-organic volume ratios (metal concentration in a few stages) with easy phase separations. Various CMPO (Octyl (phenyl) -N,N-diisobutylcarbamoylmethylphosphine oxide) containing gels have been prepared, and the extraction of europium (and related actinides) has been studied

  4. Photopatterned free-standing polyacrylamide gels for microfluidic protein electrophoresis.

    Science.gov (United States)

    Duncombe, Todd A; Herr, Amy E

    2013-06-07

    Designed for compatibility with slab-gel polyacrylamide gel electrophoresis (PAGE) reagents and instruments, we detail development of free-standing polyacrylamide gel (fsPAG) microstructures supporting electrophoretic performance rivalling that of microfluidic platforms. For the protein electrophoresis study described here, fsPAGE lanes are comprised of a sample reservoir and contiguous separation gel. No enclosed microfluidic channels are employed. The fsPAG devices (120 μm tall) are directly photopatterned atop of and covalently attached to planar polymer or glass surfaces. Leveraging the fast uses readily available materials and instruments - making this technique highly accessible.

  5. High Impulse Nanoparticulate-Based Gel Propellants, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposed Small Business Innovative Research (SBIR) Phase I addresses the development of advanced gel propellants and determination of their suitability for...

  6. Disc electrophoresis and related techniques of polyacrylamide gel electrophoresis

    National Research Council Canada - National Science Library

    Maurer, H. R

    1971-01-01

    ..., enzymes, antingens and radioactively labelled materials, and detailed treatments of micro disc electrophoresis, preparative polyacrylamide gel electrophoresis and many other techniques for special problems...

  7. Functional study on two artificial liver bioreactors with collagen gel

    Directory of Open Access Journals (Sweden)

    XU Bing

    2014-10-01

    Full Text Available ObjectiveTo improve the hollow fiber bioreactor of artificial liver. MethodsRat hepatocytes mixed with collagen solution were injected into the external cavity of a hollow fiber reactor to construct a bioreactor of hepatocytes suspended in collagen gel (group Ⅰ. Other rat hepatocytes suspended in solution were injected into the external cavity of a hollow fiber reactor with a layer of collagen on the wall of the external cavity to construct a bioreactor of collagen layer and hepatocytes (group Ⅱ. For each group, the culture solution circulated through the internal cavity of the hollow fiber bioreactor; the bioreactor was put in a culture box for 9 d, and the culture solution in the internal cavity was exchanged for new one every 24 h; the concentrations of albumin (Alb, urea, and lactate dehydrogenase (LDH in the culture solution samples were measured to examine the hepatocyte function of the bioreactor. Statistical analysis was performed using SPSS 130. Continuous data were expressed as mean±SD, and comparison between groups was made by paired t test. ResultsFor groups Ⅰ and Ⅱ, Alb levels reached peak values on day 3 of culture (1.41±0.08 g/L and 0.65±0.05 g/L; from day 3 to 9, group I had a significantly higher Alb level than group Ⅱ (t>7.572, P<0.01. For groups Ⅰ and Ⅱ, urea levels reached peak values on days 3 and 5 of culture (1.73±0.14 mmol/L and 1.56±0.18 mmol/L; from days 5 to 9, group I had a significantly higher urea level than group Ⅱ (t>8.418, P<0.01. For groups Ⅰ and Ⅱ, LDH levels reached peak values on day 9 of culture (32.03±9.13 U/L and 70.17±25.28 U/L; from days 1 to 9, group I had a significantly lower LDH level than group Ⅱ(t>5.633, P<0.01. Therefore, the bioreactor of hepatocytes suspended in collagen gel (group Ⅰ showed a better hepatocyte function and less hepatic enzyme leakage compared with the bioreactor of collagen layer and hepatocytes (group Ⅱ. Conclusion

  8. Combination effects of NaOH and NaCl on the rheology and gel characteristics of hen egg white proteins.

    Science.gov (United States)

    Li, Junhua; Zhang, Yufan; Fan, Qiao; Teng, Changhao; Xie, Weiying; Shi, Yue; Su, Yujie; Yang, Yanjun

    2018-06-01

    The effects of NaOH and NaCl on the rheology and gel properties of hen egg white were investigated. As the concentration of NaOH increased, egg white gel exhibited lower opacity and particle turbidity with coincidental increase in zeta potential, while the addition of NaCl resulted in the formation of opaque egg white gel and increase of surface hydrophobicity, particle turbidity and zeta potential. Rheological tests showed that alkali treatment will affect the unfolding state of egg white proteins during the heat stage while NaCl addition can inhibit the unfolding of egg white proteins. The results of correlation analysis indicated that random coil and α-helix were in good correlation with gel textural properties. Therefore, the rheology and gel properties of alkali/salt-induced egg white dispersions were closely related to the changes in surface hydrophobicity, molecule surface charge, and protein secondary structure. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Design of the mechanical properties of the gel by the 3D gel printer "SWIM-ER"

    Science.gov (United States)

    Saito, Azusa; Ota, Takafumi; Tase, Taishi; Takamatsu, Kyuichiro; Kawakami, Masaru; Furukawa, Hidemitsu

    2017-04-01

    In this study, we evaluated the mechanical properties of printed structures with respect to the printing orientation for "SWIM-ER". The fracture surface of the 3D modeled object of the gel does not break along the stacked line, and the maximum stress at that time is the breaking strength. Moreover, the dependency in the stacking direction is weak in the 3D model of the gel. The gel printed at high speed scan showed lower elastic modulus and higher moisture content than gel printed at low speed scan. We discussed about crosslinking density calculated based on the compressive elastic modulus and moisture content, respectively. It was found that gels having different crosslinking density can be formed by the scanning speed of UV laser. In addition, we made a prototype of a gel finger model with different mechanical properties within the model.

  10. Microwave NDE method for health-monitoring of concrete structures containing alkali-silica reaction (ASR) gel

    Science.gov (United States)

    Hashemi, A.; Hatfield, S.; Donnell, K. M.; Zoughi, R.; Kurtis, K. E.

    2014-02-01

    The presence of reactive aggregates combined with sufficient moisture and concentration of alkalis are the three basic requirements for damage due alkali-silica reaction (ASR) gel formation and expansion in concrete. For health-monitoring of concrete structures, and in order to investigate the potential for detecting ASR gel formation in existing structures, one potential technique involves studying changes in the temporal complex dielectric constant of concrete structures. In this paper, a microwave nondestructive testing approach is proposed which involves soaking two hardened mortar samples and measuring the change in their temporal complex dielectric constant in order to distinguish between the sample containing ASR gel and the one devoid of it. Part of the free water becomes bound in the sample containing ASR gel and since a portion of the microcracks in this sample contain ASR gel, the rate of evaporation of water of the two samples is expected to be different. The complex dielectric constant of the samples is significantly dependent upon the volumetric level and movement (in and out of the samples) of free water. Therefore, studying the relative different temporal rate of change in this parameter is expected to yield information about the presence or absence of ASR gel.

  11. Development and characterization of a family of shape memory, biocompatible, degradable, porous (co)-polyurethanes via sol-gel chemistry

    Science.gov (United States)

    Lippincott, Hugh Walker

    In support of the goal of a tissue engineering scaffold that is moldable, biodegradable and has shape-memory, this work explored the space of polyurethane sol-gel formulations and solvents to create a biocompatible, porous xerogel with potential to be such a porous scaffold. The work has resulted in both a process and a sol-gel formulation to effectively create a family of degradable, biocompatible, shape memory, porous, block copolyurethane xerogels from polycaprolactone and castor oil. Formulations of the sol-gel family of potential scaffolds were characterized for their biocompatibility, hydrolytic degradability, porosity, and shape memory. Of the scaffolds tested in this fashion, the most successful supported the attachment and growth of 3T3 fibroblast cells at 72% of the rate of attachment and growth in the standard tissue culture plastic Petri dishes. A method was developed and explained that selects the solvent for creation of a porous xerogel by controlling the phase separation of the polymerizing polyurethane from the reaction solution. This method uses standard polymer solvent swelling and extraction test data. Solvent solutions plotted in the 3-D space of Hansen solubility parameters were used to select solvents that produced porous xerogels from two different polyurethane sol-gel formulations. The process effectively combines a set of methods that search the sol-gel formulation spaces for both shape-memory and porosity. Easily produced dense xerogels from trial sol-gel formulations are sufficient for DSC and initial DMA shape-memory test data, as well as standard solvent swelling and extraction test data to support the search for shape memory and the computation of rankings to select solvent(s) that is most likely to produce a porous xerogel. Accelerated degradation tests on the dense xerogels also produced results useful to guide further testing of the sol-gel formulations. Standard shape-memory research testing only characterizes the free return to

  12. Matrix molecularly imprinted mesoporous sol-gel sorbent for efficient solid-phase extraction of chloramphenicol from milk.

    Science.gov (United States)

    Samanidou, Victoria; Kehagia, Maria; Kabir, Abuzar; Furton, Kenneth G

    2016-03-31

    Highly selective and efficient chloramphenicol imprinted sol-gel silica based inorganic polymeric sorbent (sol-gel MIP) was synthesized via matrix imprinting approach for the extraction of chloramphenicol in milk. Chloramphenicol was used as the template molecule, 3-aminopropyltriethoxysilane (3-APTES) and triethoxyphenylsilane (TEPS) as the functional precursors, tetramethyl orthosilicate (TMOS) as the cross-linker, isopropanol as the solvent/porogen, and HCl as the sol-gel catalyst. Non-imprinted sol-gel polymer (sol-gel NIP) was synthesized under identical conditions in absence of template molecules for comparison purpose. Both synthesized materials were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and nitrogen adsorption porosimetry, which unambiguously confirmed their significant structural and morphological differences. The synthesized MIP and NIP materials were evaluated as sorbents for molecularly imprinted solid phase extraction (MISPE) of chloramphenicol in milk. The effect of critical extraction parameters (flow rate, elution solvent, sample and eluent volume, selectivity coefficient, retention capacity) was studied in terms of retention and desorption of chloramphenicol. Competition and cross reactivity tests have proved that sol-gel MIP sorbent possesses significantly higher specific retention and enrichment capacity for chloramphenicol compared to its non-imprinted analogue. The maximum imprinting factor (IF) was found as 9.7, whereas the highest adsorption capacity of chloramphenicol by sol-gel MIP was 23 mg/g. The sol-gel MIP was found to be adequately selective towards chloramphenicol to provide the necessary minimum required performance limit (MRPL) of 0.3 μg/kg set forth by European Commission after analysis by LC-MS even without requiring time consuming solvent evaporation and sample reconstitution step, often considered as an integral part in solid phase extraction work-flow. Intra and

  13. UPDATING HIGH SCHOOL TEACHERS ON GEL ELETROPHORESIS AND RESTRICTION ENZYMES

    Directory of Open Access Journals (Sweden)

    V.S. Barbuto,

    2007-05-01

    Full Text Available The current evolution of the science and technology generated a demand in the teachers' formation that needs constant updating. In that sense, CBME has been elaborating courses and workshops to update teachers of Sciences and Biology involving current themes.  The activities on  Molecular  Biotechnology were elaborated, especially on restriction enzymes and gel electrophoresis.  Thirty-seven teachers of public schools participated in the activities. Firstly, it was made an experiment demonstrating the digestion of a plasmidial DNA by two restriction enzymes (DraI  and  EcoRI, with the subsequent application in gel, in order to elucidate the electrophoresis technique. After the demonstration, simple and practical exercises were distributed  to the teachers to simulate those processes using paper ribbons and charts,  being  concluded with an exercise of a paternity test. A questionnaire was applied as an evaluation tool and from the teachers' answers it was observed, among other data, that 100%  of the teachers classified the activities as interesting, 43% classified the thematic as actual, 22% defined it as appropriate to their school reality and 19% pointed it as a subject on which they have doubts. Also, it was observed that the teachers felt confident dealing with the most specific subjects, when relating it with the daily events and visualizing a possibility of didactic transposition of those themes.

  14. Anti-biofilm activity of chitosan gels formulated with silver nanoparticles and their cytotoxic effect on human fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Pérez-Díaz, M.; Alvarado-Gomez, E. [Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi (Mexico); Magaña-Aquino, M. [Servicio de Epidemiologia del Hospital Central “Dr. Ignacio Morones Prieto”, San Luis Potosi (Mexico); Sánchez-Sánchez, R.; Velasquillo, C. [Laboratorio de Biotecnologia, Instituto Nacional de Rehabilitacion, Mexico, D.F. (Mexico); Gonzalez, C. [Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi (Mexico); Ganem-Rondero, A. [Division de Estudios de Posgrado (Tecnologia Farmaceutica), Facultad de Estudios Superiores Cuautitlan, Universidad Nacional Autonoma de Mexico, Cuautitlan Izcalli, Estado de Mexico (Mexico); Martínez-Castañon, G.; Zavala-Alonso, N. [Doctorado en Ciencias Odontológicas Facultad de Estomatologia, UASLP (Mexico); Martinez-Gutierrez, F. [Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi (Mexico)

    2016-03-01

    The development of multi-species biofilms in chronic wounds is a serious health problem that primarily generates strong resistance mechanisms to antimicrobial therapy. The use of silver nanoparticles (AgNPs) as a broad-spectrum antimicrobial agent has been studied previously. However, their cytotoxic effects limit its use within the medical area. The purpose of this study was to evaluate the anti-biofilm capacity of chitosan gel formulations loaded with AgNPs, using silver sulfadiazine (SSD) as a standard treatment, on strains of clinical isolates, as well as their cytotoxic effect on human primary fibroblasts. Multi-species biofilm of Staphylococcus aureus oxacillin resistant (MRSA) and Pseudomonas aeruginosa obtained from a patient with chronic wound infection were carried out using a standard Drip Flow Reactor (DFR) under conditions that mimic the flow of nutrients in the human skin. Anti-biofilm activity of chitosan gels and SSD showed a log-reduction of 6.0 for MRSA when chitosan gel with AgNPs at a concentration of 100 ppm was used, however it was necessary to increase the concentration of the chitosan gel with AgNPs to 1000 ppm to get a log-reduction of 3.3, while the SSD showed a total reduction of both bacteria in comparison with the negative control. The biocompatibility evaluation on primary fibroblasts showed better results when the chitosan gels with AgNPs were tested even in the high concentration, in contrast with SSD, which killed all the primary fibroblasts. In conclusion, chitosan gel formulations loaded with AgNPs effectively prevent the formation of biofilm and kill bacteria in established biofilm, which suggest that chitosan gels with AgNPs could be used for prevention and treatment of infections in chronic wounds. The statistic significance of the biocompatibility of chitosan gel formulations loaded with AgNPs represents an advance; however further research and development are necessary to translate this technology into therapeutic and

  15. Anti-biofilm activity of chitosan gels formulated with silver nanoparticles and their cytotoxic effect on human fibroblasts

    International Nuclear Information System (INIS)

    Pérez-Díaz, M.; Alvarado-Gomez, E.; Magaña-Aquino, M.; Sánchez-Sánchez, R.; Velasquillo, C.; Gonzalez, C.; Ganem-Rondero, A.; Martínez-Castañon, G.; Zavala-Alonso, N.; Martinez-Gutierrez, F.

    2016-01-01

    The development of multi-species biofilms in chronic wounds is a serious health problem that primarily generates strong resistance mechanisms to antimicrobial therapy. The use of silver nanoparticles (AgNPs) as a broad-spectrum antimicrobial agent has been studied previously. However, their cytotoxic effects limit its use within the medical area. The purpose of this study was to evaluate the anti-biofilm capacity of chitosan gel formulations loaded with AgNPs, using silver sulfadiazine (SSD) as a standard treatment, on strains of clinical isolates, as well as their cytotoxic effect on human primary fibroblasts. Multi-species biofilm of Staphylococcus aureus oxacillin resistant (MRSA) and Pseudomonas aeruginosa obtained from a patient with chronic wound infection were carried out using a standard Drip Flow Reactor (DFR) under conditions that mimic the flow of nutrients in the human skin. Anti-biofilm activity of chitosan gels and SSD showed a log-reduction of 6.0 for MRSA when chitosan gel with AgNPs at a concentration of 100 ppm was used, however it was necessary to increase the concentration of the chitosan gel with AgNPs to 1000 ppm to get a log-reduction of 3.3, while the SSD showed a total reduction of both bacteria in comparison with the negative control. The biocompatibility evaluation on primary fibroblasts showed better results when the chitosan gels with AgNPs were tested even in the high concentration, in contrast with SSD, which killed all the primary fibroblasts. In conclusion, chitosan gel formulations loaded with AgNPs effectively prevent the formation of biofilm and kill bacteria in established biofilm, which suggest that chitosan gels with AgNPs could be used for prevention and treatment of infections in chronic wounds. The statistic significance of the biocompatibility of chitosan gel formulations loaded with AgNPs represents an advance; however further research and development are necessary to translate this technology into therapeutic and

  16. Influence of Uranium and Polivinyl Alcohol Concentration in the Feed of Sol Gel Process on the Gel Spherical Product

    International Nuclear Information System (INIS)

    Indra Suryawan; Endang Susiantini

    2007-01-01

    The gel particles have been made at various uranium and polyvinyl alcohol concentration in the sol gel process. The variables of uranium concentration were 0.3; 0.5; 0.7; 0.9; 1.1; 1.3; 1.5; 1.7; 1.9 and 2.1 M The variables of polyvinyl alcohol concentration were 0.3; 0.6; 0.9; 1.2; 1.5; 1.8; 2.1 and 2.4 M After drying the sol gel process products were heated at 300, 500 and 750°C during 4 hours. The gel particles were characterized using an optic microscope to know the shape and condition morphology of gel. From experimental result using uranium concentration of 0.3 until 2.1 M and polyvinyl alcohol of 1.8 until 2.4 M spherical and gel was formed elastic, after heating at 750°C it was unbreakable. At the concentration of polyvinyl alcohol from 0.3 to 0.5 M, the gel product was soft and broken after being dried. At the concentration of polyvinyl alcohol from 0.6 to 0.8 M, the dried gel product was not perfect. At the concentration of polyvinyl alcohol from 0.9 to 1.7 M, the gel product of gelation process was spherical and it was broken after being heated up to 300°C. (author)

  17. Radiological properties of MAGIC normoxic polymer gel dosimetry

    Science.gov (United States)

    Aljamal, M.; Zakaria, A.; Shamsuddin, S.

    2013-04-01

    For a polymer gel dosimeter to be of use in radiation dosimetry, it should display water-equivalent radiological properties. In this study, the radiological properties of the MAGIC (Methacrylic and Ascorbic acid in Gelatin Initiated by Copper) normoxic polymer gels were investigated. The mass density (ρ) was determined based on Archimedes' principle. The weight fraction of elemental composition and the effective atomic number (Zeff) were calculated. The electron density was also measured with 90° scattering angle at room temperature. The linear attenuation coefficient (μ) of unirradiated gel, irradiated gel, and water were determined using Am-241 based on narrow beam geometry. Monte Carlo simulation was used to calculate the depth doses response of MAGIC gel and water for 6MV photon beam. The weight fractions of elements composition of MAGIC gel were close to that for water. The mass density was found to be 1027 ± 2 kg m-3, which is also very close to mass density of muscle tissue (1030 kg m-3) and 2.7% higher than that of water. The electron density (ρe) and atomic number (Zeff) were found to be 3.43 × 1029 e m-3 and 7.105, respectively. The electron density measured was 2.6% greater than that for water. The atomic number was very close to that for water. The prepared MAGIC gel was found to be water equivalent based on the study of element composition, mass density, electron density and atomic number. The linear attenuation coefficient of unirradiated gel was very close to that of water. The μ of irradiated gel was found to be linear with dose 2-40 Gy. The depth dose response for MAGIC gel from a 6 MV photon beam had a percentage dose difference to water of less than 1%. Therefore it satisfies the criteria to be a good polymer gel dosimeter for radiotherapy.

  18. Sorption of neptunium(V) on silicate gels

    International Nuclear Information System (INIS)

    Del Nero, M.; Bontems, G.; Advocat, T.; Jollivet, P.

    1999-01-01

    Aqueous corrosion of nuclear waste glasses induces the formation of a gel layer enriched in hydrolyzable elements. To assess the role of such layers on the migration of Np(V) from repositories to environment, and determine the retention mechanisms, experiments have been undertaken on synthetic pure silica and on ferrisilicate gels as model solids. No detailed and systematic studies on silicate gels as scavengers for Np(V) appear to have been devoted to the influence of solution parameters and gel composition on the sorption of Np(V) on silicate gels. In this work, the fractional uptake of Np(V) on a synthetic pure silica gel and on synthetic ferrisilicate gels of controlled Si/Fe proportions (3 and 10) was measured at different ionic strengths (0.5 to 0.01 M) and Np(V) concentration levels ≅10 -10 M and 10 -6 M with pH as the main variable (3 to 10). The pH dependence of Np(V) sorption on the alternation gel was also investigated for different initial concentrations of Np(V) in the aqueous phase ≅10 -10 M, 10 -6 M and 10 -5 M. Batch experiments were carried out at 298 K under CO 2 -free conditions to avoid the formation of Np(V) carbonate complexes in the solution. As a part of this work, the charge characteristics of the gel surfaces were determined either by studying the retention of the electrolyte ions as counterions to the surface charges, as a function of pH and ionic strength of the solution contacted with gels, or by performing acid/base titrations of the alteration gel suspensions. (J.P.N.)

  19. Diffusion MRI for rectal cancer staging: ADC measurements before and after ultrasonographic gel lumen distension

    Energy Technology Data Exchange (ETDEWEB)

    Palmucci, S., E-mail: spalmucci@sirm.org; Piccoli, M.; Piana, S.; Foti, P.V.; Siverino, R.O.A.; Mauro, L.A.; Milone, P.; Ettorre, G.C.

    2017-01-15

    Objectives: To compare Apparent Diffusion Coefficient (ADC) measurements in rectal neoplastic lesions before and after lumen distension obtained with sonography transmission gel. Methods: From January 2014 to July 2016, 25 patients (average age 63.7, range 41–85, 18 males) were studied for pre-treatment rectal cancer staging using a 1.5 T MRI. Diffusion MRI was obtained using echo-planar imaging with b = 800 value; all patients were studied acquiring diffusion sequences with and without rectal lumen distension obtained using sonography transmission gel. In both diffusion sequences, two blinded readers calculated border ADC values and small ADC values, drawing regions of interest respectively along tumour borders and far from tumour borders. Mean ADC values among readers − for each type of ADC measurement − were compared using Wilcoxon matched pairs signed rank test. Correlation was assessed using Pearson analysis. Results: Border ADC mean value for diffusion MR sequences without endorectal contrast was 1.122 mm{sup 2}/sec, with 95% Confidence Interval (CI) = 1.02–1.22; using gel lumen distension, higher border ADC mean value of 1.269 mm{sup 2}/s (95% CI = 1.16–1.38) was obtained. Wilcoxon matched pairs signed rank test revealed statistical difference (p < 0.01); a strong Pearson correlation was reported, with r value of 0.69. Small-ADC mean value was 1.038 mm{sup 2}/s (95% CI = 0.91–1.16) for diffusion sequences acquired without endorectal distension and 1.127 mm{sup 2}/s (95% CI = 0.98–1.27) for diffusion sequences obtained after endorectal gel lumen distension. Wilcoxon analysis did not show statistical difference (p = 0.13). A very strong positive correlation was observed, with r value of 0.81. Conclusions: ADC measurements are slightly higher using endorectal sonographic transmission gel; ROI should be traced far from tumour borders, to minimize gel filled-pixel along the interface between lumen and lesion. Further studies are needed to

  20. Multifactorial study and kinetics of signal development in ferrous-methylthymol blue-gelatin gel dosimeters.

    Science.gov (United States)

    Penev, Kalin I; Mequanint, Kibret

    2017-05-01

    To develop and characterize a ferrous-methylthymol blue-gelatin gel dosimeter with low optical background and appropriate additives for reduced rate of auto-oxidation and diffusion. A mixed-level multifactorial design of experiments was used to test the effects of the concentrations of sulfuric acid, 5-nitro-1,10-phenanthroline (Nn), and glyoxal (Gx) on the background absorbance, dose sensitivity, and auto-oxidation of the tested gel dosimeter. The dosimetric properties of the proposed ferrous-methylthymol blue-gelatin dosimeter, doped with Nn and Gx, were compared with the undoped formulation and with ferrous-xylenol orange-gelatin gel dosimeters. Irradiations were performed in both small-scale cuvette samples and large 400-mL bulk samples. In addition to that, a new kinetic model for the signal development postirradiation was derived based on chemical principles and used for comparison of the different formulations. The new formulation showed a reduced auto-oxidation rate, while maintaining low background absorbance relative to the common ferrous-xylenol orange-gelatin gel dosimeter. Compared with undoped ferrous-xylenol orange or ferrous-methylthymol blue gels, the dose sensitivity of the new formulation is approximately 2 to 3 times lower, but remains clinically adequate. A previously unreported dose rate dependence of the dose sensitivity was observed, and a new kinetic model for the signal development postirradiation was used to investigate this effect. Similar dose rate dependences in gels containing either methylthymol blue or xylenol orange, with or without doping with Nn and Gx, were observed, suggesting that the low ferrous ammonium sulfate concentrations used in studied formulations were responsible for this effect. A multifactorial design of experiments and a new kinetic model for the signal development postirradiation were successfully employed to optimize the composition and characterize the properties of a new ferrous-methylthymol blue-gelatin gel

  1. Intracervical lidocaine gel for intrauterine device insertion: a randomized controlled trial.

    Science.gov (United States)

    Maguire, Karla; Davis, Anne; Rosario Tejeda, Linette; Westhoff, Carolyn

    2012-09-01

    Pain during intrauterine device (IUD) insertion can be a barrier to initiation. Clinical trials have found misoprostol and nonsteroidal drugs to be ineffective (Am J Obstet Gynecol 2006;195:1272-1277, Hum Reprod 2011;26:323-329, Hum Reprod 2007;22:2647-2652). One study suggested that 2% lidocaine gel decreased pain; however, study design problems limit its validity (Brit J Fam Plann 1996;22:177-180). We tested whether intracervical 2% lidocaine gel decreased insertion pain compared to placebo. We planned a randomized, double-blinded clinical trial of 200 women. We placed 2% lidocaine gel or placebo in the cervix prior to uterine sounding. Participants rated pain by marking a 100-mm visual analogue scale at four time points. We randomized 200 participants and placed 197 IUDs. Pain was greatest at uterine sounding and similar between groups: placebo group mean 51.6 mm (SD 25), lidocaine group mean 55.5 mm (SD 30, p=.33). Stratified analyses accounting for parity showed no treatment effect. Multivariable analyses identified longer time since last pregnancy, lower parity and higher anticipated pain as predictors of pain during sounding, and dysmenorrhea and the levonorgestrel IUD as additional predictors during IUD insertion. Intracervical 2% lidocaine gel does not decrease IUD insertion pain. Understanding predictors of increased pain may help providers with preprocedure counseling. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Mathematical Modeling of Uniaxial Mechanical Properties of Collagen Gel Scaffolds for Vascular Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Ramiro M. Irastorza

    2015-01-01

    Full Text Available Small diameter tissue-engineered arteries improve their mechanical and functional properties when they are mechanically stimulated. Applying a suitable stress and/or strain with or without a cycle to the scaffolds and cells during the culturing process resides in our ability to generate a suitable mechanical model. Collagen gel is one of the most used scaffolds in vascular tissue engineering, mainly because it is the principal constituent of the extracellular matrix for vascular cells in human. The mechanical modeling of such a material is not a trivial task, mainly for its viscoelastic nature. Computational and experimental methods for developing a suitable model for collagen gels are of primary importance for the field. In this research, we focused on mechanical properties of collagen gels under unconfined compression. First, mechanical viscoelastic models are discussed and framed in the control system theory. Second, models are fitted using system identification. Several models are evaluated and two nonlinear models are proposed: Mooney-Rivlin inspired and Hammerstein models. The results suggest that Mooney-Rivlin and Hammerstein models succeed in describing the mechanical behavior of collagen gels for cyclic tests on scaffolds (with best fitting parameters 58.3% and 75.8%, resp.. When Akaike criterion is used, the best is the Mooney-Rivlin inspired model.

  3. Foldable and Cytocompatible Sol-gel TiO2 Photonics.

    Science.gov (United States)

    Li, Lan; Zhang, Ping; Wang, Wei-Ming; Lin, Hongtao; Zerdoum, Aidan B; Geiger, Sarah J; Liu, Yangchen; Xiao, Nicholas; Zou, Yi; Ogbuu, Okechukwu; Du, Qingyang; Jia, Xinqiao; Li, Jingjing; Hu, Juejun

    2015-09-07

    Integrated photonics provides a miniaturized and potentially implantable platform to manipulate and enhance the interactions between light and biological molecules or tissues in in-vitro and in-vivo settings, and is thus being increasingly adopted in a wide cross-section of biomedical applications ranging from disease diagnosis to optogenetic neuromodulation. However, the mechanical rigidity of substrates traditionally used for photonic integration is fundamentally incompatible with soft biological tissues. Cytotoxicity of materials and chemicals used in photonic device processing imposes another constraint towards these biophotonic applications. Here we present thin film TiO2 as a viable material for biocompatible and flexible integrated photonics. Amorphous TiO2 films were deposited using a low temperature (<250 °C) sol-gel process fully compatible with monolithic integration on plastic substrates. High-index-contrast flexible optical waveguides and resonators were fabricated using the sol-gel TiO2 material, and resonator quality factors up to 20,000 were measured. Following a multi-neutral-axis mechanical design, these devices exhibit remarkable mechanical flexibility, and can sustain repeated folding without compromising their optical performance. Finally, we validated the low cytotoxicity of the sol-gel TiO2 devices through in-vitro cell culture tests. These results demonstrate the potential of sol-gel TiO2 as a promising material platform for novel biophotonic devices.

  4. In vitro activity of Aloe vera inner gel against microorganisms grown in planktonic and sessile phases.

    Science.gov (United States)

    Cataldi, V; Di Bartolomeo, S; Di Campli, E; Nostro, A; Cellini, L; Di Giulio, M

    2015-12-01

    The failure of traditional antimicrobial treatments is becoming a worldwide problem. The use of Aloe vera is of particular interest for its role as curative agent and its efficacy in complementary therapies for a variety of illnesses. This study evaluated the antimicrobial activity of A. vera inner gel against a panel of microorganisms, Gram-positive and -negative bacteria, and Candida albicans. In addition to A. vera inner gel being used in the treatment of peptic ulcers, in dermatological treatments, and wound healing, it was also tested on the sessile phase of clinical Helicobacter pylori strains (including multi-drug-resistant strains) and on planktonic and sessile phase of Staphylococcus aureus/Pseudomonas aeruginosa clinical isolates from venous leg ulcers.A. vera inner gel expresses its prevalent activity against Gram-negative bacteria and C. albicans in respect to Gram-positive bacteria. The results of the A. vera antibiofilm activity showed a decrease of the produced biomass in a concentration-dependent-way, in each analyzed microorganism. The data obtained show that A. vera inner gel has both an antimicrobial and antibiofilm activity suggesting its potential use for the treatment of microbial infections, in particular for H. pylori gastric infection, especially in case of multi-drug-resistance, as well as for an effective wound dressing. © The Author(s) 2015.

  5. Mathematical modeling of uniaxial mechanical properties of collagen gel scaffolds for vascular tissue engineering.

    Science.gov (United States)

    Irastorza, Ramiro M; Drouin, Bernard; Blangino, Eugenia; Mantovani, Diego

    2015-01-01

    Small diameter tissue-engineered arteries improve their mechanical and functional properties when they are mechanically stimulated. Applying a suitable stress and/or strain with or without a cycle to the scaffolds and cells during the culturing process resides in our ability to generate a suitable mechanical model. Collagen gel is one of the most used scaffolds in vascular tissue engineering, mainly because it is the principal constituent of the extracellular matrix for vascular cells in human. The mechanical modeling of such a material is not a trivial task, mainly for its viscoelastic nature. Computational and experimental methods for developing a suitable model for collagen gels are of primary importance for the field. In this research, we focused on mechanical properties of collagen gels under unconfined compression. First, mechanical viscoelastic models are discussed and framed in the control system theory. Second, models are fitted using system identification. Several models are evaluated and two nonlinear models are proposed: Mooney-Rivlin inspired and Hammerstein models. The results suggest that Mooney-Rivlin and Hammerstein models succeed in describing the mechanical behavior of collagen gels for cyclic tests on scaffolds (with best fitting parameters 58.3% and 75.8%, resp.). When Akaike criterion is used, the best is the Mooney-Rivlin inspired model.

  6. Multifunctional nano-hydroxyapatite and alginate/gelatin based sticky gel composites for potential bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Yurong; Yu, Juhong [The Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, National Engineering Lab of Textile Fiber Materials & Processing Technology, College of Materials and Textile, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Kundu, Subhas C. [Department of Biotechnology, Indian Institute of Technology (IIT) Kharagpur, West Bengal 721302 (India); Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan 330-714 (Korea, Republic of); Yao, Juming, E-mail: yaoj@zstu.edu.cn [The Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, National Engineering Lab of Textile Fiber Materials & Processing Technology, College of Materials and Textile, Zhejiang Sci-Tech University, Hangzhou 310018 (China)

    2016-09-15

    To improve the fixations of the implant and implant-bone integration after joint arthroplasty from locally preventing inflammation and promoting the bone regeneration, we design a multifunctional biomaterial consisting of recombinant human bone morphogenetic protein 2 (rhBMP-2) and antibiotic loaded nano-hydroxyapatite with an alginate/gelatin sticky gel. We investigate its role for the prevention of the inflammation and possibility of inducing a new bone growth along with its adhesive ability. The stickiness exists in the composite, which may help to fix itself on the bone fracture surface. The composite sustains the antibacterial effect and promotes the proliferation and differentiation of MG63 cells in vitro. In vivo experimentation also shows that the composite gel has a role for the reduction of inflammation. It enhances the formation of new bone and blood vessels compared to both the sole rhBMP-2 and non-rhBMP-2/antibiotic loaded composite gels. The multifunctional composite provides a promising material for the prosthetic and bone tissue regeneration. - Highlights: • Multifunctional nanohydroxyapatite composite is fabricated. • The composite consists of nHAP, growth factor, antibiotic and alginate/gelatin gel. • The composite shows antibacterial effect and good cytocompatibility. • No adverse effect to the cells tested in vitro and in vivo.

  7. Silica-Based Sol-Gel Coating on Magnesium Alloy with Green Inhibitors

    Directory of Open Access Journals (Sweden)

    Vinod Upadhyay

    2017-06-01

    Full Text Available In this work, the performances of several natural organic inhibitors were investigated in a sol-gel system (applied on the magnesium alloy Mg AZ31B substrate. The inhibitors were quinaldic acid (QDA, betaine (BET, dopamine hydrochloride (DOP, and diazolidinyl urea (DZU. Thin, uniform, and defect-free sol-gel coatings were prepared with and without organic inhibitors, and applied on the Mg AZ31B substrate. SEM and EDX were performed to analyze the coating surface properties, the adhesion to the substrate, and the thickness. Electrochemical measurements, including electrochemical impedance spectroscopy (EIS and anodic potentiodynamic polarization scan (PDS, were performed on the coated samples to characterize the coatings’ protective properties. Also, hydrogen evolution measurement—an easy method to measure magnesium corrosion—was performed in order to characterize the efficiency of coating protection on the magnesium substrate. Moreover, scanning vibrating electrode technique (SVET measurements were performed to examine the efficiency of the coatings loaded with inhibitors in preventing and containing corrosion events in defect areas. From the testing results it was observed that the formulated sol-gel coatings provided a good barrier to the substrate, affording some protection even without the presence of inhibitors. Finally, when the inhibitors’ performances were compared, the QDA-doped sol-gel was able to contain the corrosion event at the defect.

  8. Local Pixel Value Collection Algorithm for Spot Segmentation in Two-Dimensional Gel Electrophoresis Research

    Directory of Open Access Journals (Sweden)

    Peter Peer

    2007-09-01

    Full Text Available Two-dimensional gel-electrophoresis (2-DE images show the expression levels of several hundreds of proteins where each protein is represented as a blob-shaped spot of grey level values. The spot detection, that is, the segmentation process has to be efficient as it is the first step in the gel processing. Such extraction of information is a very complex task. In this paper, we propose a novel spot detector that is basically a morphology-based method with the use of a seeded region growing as a central paradigm and which relies on the spot correlation information. The method is tested on our synthetic as well as on real gels with human samples from SWISS-2DPAGE (two-dimensional polyacrylamide gel electrophoresis database. A comparison of results is done with a method called pixel value collection (PVC. Since our algorithm efficiently uses local spot information, segments the spot by collecting pixel values and its affinity with PVC, we named it local pixel value collection (LPVC. The results show that LPVC achieves similar segmentation results as PVC, but is much faster than PVC.

  9. Adhesion enhancement of sol-gel coating on polycarbonate by heated impregnation treatment

    International Nuclear Information System (INIS)

    Wu, Linda Y.L.; Boon, L.; Chen, Z.; Zeng, X.T.

    2009-01-01

    The main limitation in using coated plastics for optical components, electronic applications and display systems is the softness of the substrate surfaces, which is responsible for the low impact and abrasion resistance and weak adhesion between the coating and the substrate. In this paper, we report a new strategy for surface pre-treatment of plastics using heated vacuum equipment and sol-gel materials to provide both chemical bonds and penetrated hard layer into the plastic surface to increase the overall performance of the coated plastic components. The heated vacuum treatment process involves: (1) surface cleaning and pore opening by heating and vacuum conditions, (2) impregnation of hydrolyzed hybrid precursor into polymer substrate under pressure and elevated temperature, (3) aminolysis of diffused precursor with surface to form chemical bonds and hardened surface layer, (4) formation of chemical bonds at treated surface with sol-gel hard coating. An impregnation depth of 1.5 μm was detected. Water contact angle dropped to below 40 o and roughness increased after treatment. These provided better adhesion by increased wettability and contact area. Much increased nanoindentation hardness and Young's modulus after impregnation provided a gradient in mechanical properties between soft substrate and hard sol-gel coating. The hardened substrate delays the plastic deformation in substrate during pencil scratch test, thereby preventing early gouge failure. Both the better adhesion and the delayed gouge failure contributed to the increased scratch resistance from 6B to 8H after sol-gel coating.

  10. Adaptive mean filtering for noise reduction in CT polymer gel dosimetry

    International Nuclear Information System (INIS)

    Hilts, Michelle; Jirasek, Andrew

    2008-01-01

    X-ray computed tomography (CT) as a method of extracting 3D dose information from irradiated polymer gel dosimeters is showing potential as a practical means to implement gel dosimetry in a radiation therapy clinic. However, the response of CT contrast to dose is weak and noise reduction is critical in order to achieve adequate dose resolutions with this method. Phantom design and CT imaging technique have both been shown to decrease image noise. In addition, image postprocessing using noise reduction filtering techniques have been proposed. This work evaluates in detail the use of the adaptive mean filter for reducing noise in CT gel dosimetry. Filter performance is systematically tested using both synthetic patterns mimicking a range of clinical dose distribution features as well as actual clinical dose distributions. Both low and high signal-to-noise ratio (SNR) situations are examined. For all cases, the effects of filter kernel size and the number of iterations are investigated. Results indicate that adaptive mean filtering is a highly effective tool for noise reduction CT gel dosimetry. The optimum filtering strategy depends on characteristics of the dose distributions and image noise level. For low noise images (SNR ∼20), the filtered results are excellent and use of adaptive mean filtering is recommended as a standard processing tool. For high noise images (SNR ∼5) adaptive mean filtering can also produce excellent results, but filtering must be approached with more caution as spatial and dose distortions of the original dose distribution can occur

  11. Preparation of Metal Immobilized Orange Waste Gel for Arsenic(V Removal From Water

    Directory of Open Access Journals (Sweden)

    Biplob Kumar Biswas

    2014-05-01

    Full Text Available Abstract - The toxicity of arsenic is known to be a risk to aquatic flora and fauna and to human health even in relatively low concentration. In this research an adsorption gel was prepared from agricultural waste material (orange waste through simple chemical modification in the view to remove arsenic (V from water. Orange waste was crushed into small particles and saponified with Ca(OH2 to prepare saponified orange waste, which was further modified by immobilizing gadolinium(III to obtain desired adsorption material (Gd(III-immobilized SOW gel. The effective pH range for arsenic adsorption was found to be 7.5 – 8.5. Adsorption capacity of the gel was evaluated to be 0.45 mol-arsenic (V/kg. Dynamic adsorption of arsenic (V in column-mode was conducted and a dynamic capacity was found to be 0.39 mol/kg. Elution of arsenate was tested after complete saturation of the column packed with gadolinium-immobilized orange waste adsorption gel. A complete elution of arsenate was achieved with the help of 1 M HCl and 28 times pre-concentration factor was attained. This study showed that a cheap and abundant agro-industrial waste material could be successfully employed for the remediation of arsenic pollution in aquatic environment. Keywords: Arsenic; Orange waste; Gadolinium(III; Adsorption; Elution.

  12. Serodiagnosis of Trypanosoma cruzi Infection Using the New Particle Gel Immunoassay - ID-PaGIA Chagas

    Directory of Open Access Journals (Sweden)

    Ana Rabello

    1999-01-01

    Full Text Available The ID-Chagas test is a particle gel immunoassay (PaGIA. Red coloured particles are sensitised with three different synthetic peptides representing antigen sequences of Trypanosoma cruzi: Ag2, TcD and TcE. When these particles are mixed with serum containing specific antibodies, they agglutinate. The reaction mixture is centrifuged through a gel filtration matrix allowing free agglutinated particles to remain trapped on the top or distributed within the gel. The result can be read visually. In order to investigate the ability of the ID-PaGIA to discriminate negative and positive sera, 111 negative and 119 positive, collected in four different Brazilian institutions, were tested by each of the participants. All sera were previously classified as positive or negative according to results obtained with three conventional tests (indirect immunofluorescence, indirect hemaglutination, and enzime linked immunosorbent assay. Sensitivity rates of ID-PaGIA varied from 95.7% to 97.4% with mean sensitivity of 96.8% and specificity rates varied from 93.8 to 98.8% with mean specificity of 94.6%. The overall Kappa test was 0.94. The assay presents as advantages the simplicity of operation and the reaction time of 20 min. In this study, ID-PaGIA showed to be highly sensitive and specific.

  13. The Gelså River Restoration Revisited

    DEFF Research Database (Denmark)

    Friberg, Nikolai; Baattrup-Pedersen, Annette; Kristensen, Esben

    2014-01-01

    The study was undertaken on the River Gelså, Denmark, where a 1.8 km meandering course was estab-lished in 1989 to replace a channelized river reach. This restoration project was the first of its kind inDenmark and has the longest time-series of post-intervention data of any restoration project...... to saturationin 1997 and that only limited immigration of new species occurred in the intervening period until 2008.The lack of long term benefits could be attributed to the simultaneous cessation of weed cutting (whichhad almost as big a positive impact as restoration), other types of stress on the river...... conductedworld-wide. Additionally, a 0.5 km upstream (control) reach that remained channelized has been sampledsince 1989. In this paper, we examined macroinvertebrate assemblages in distinct habitats in 2008, 19years after the restoration, and community persistence between two years, 1997 and 2008...

  14. Bucky gel actuator displacement: experiment and model

    International Nuclear Information System (INIS)

    Ghamsari, A K; Zegeye, E; Woldesenbet, E; Jin, Y

    2013-01-01

    Bucky gel actuator (BGA) is a dry electroactive nanocomposite which is driven with a few volts. BGA’s remarkable features make this tri-layered actuator a potential candidate for morphing applications. However, most of these applications would require a better understanding of the effective parameters that influence the BGA displacement. In this study, various sets of experiments were designed to investigate the effect of several parameters on the maximum lateral displacement of BGA. Two input parameters, voltage and frequency, and three material/design parameters, carbon nanotube type, thickness, and weight fraction of constituents were selected. A new thickness ratio term was also introduced to study the role of individual layers on BGA displacement. A model was established to predict BGA maximum displacement based on the effect of these parameters. This model showed good agreement with reported results from the literature. In addition, an important factor in the design of BGA-based devices, lifetime, was investigated. (paper)

  15. Novel inorganic tin phosphate gel: multifunctional material.

    Science.gov (United States)

    Huang, Wenyan; Komarneni, Sridhar; Noh, Young Dong; Ma, Jianfeng; Chen, Kunfeng; Xue, Dongfeng; Xue, Xiaoqiang; Jiang, Bibiao

    2018-03-08

    Here, we report a remarkable 15 Å nanolayered tin phosphate, Sn(HPO 4 ) 2 ·3H 2 O (SnP-H + or SnP), and its clay-like gel, which are multifunctional and are prepared using earth-abundant Sn and P chemicals by a facile, environmentally benign and potentially cost-effective process. This new energy material is discovered here as the best proton conductor among all the known layered phosphates with a very high proton conductivity of over 1 × 10 -2 S cm -1 at 100 °C for potential use in PEM fuel cells. But it is also a very good capacitor material with fast Li-storage kinetics (charging time of 13 s).

  16. Phyllosilicates and Amorphous Gel in the Nakhlites

    Science.gov (United States)

    Hicks, L. J.; Bridges, J. C.; Gurman, S. J.

    2013-09-01

    Previous studies of the nakhlite martian meteorites have revealed hydrothermal minerals present within the fractures of the olivine minerals and the mesostasis. The olivine fractures of the Lafayette nakhlite reveal variations with initial deposits of siderite on the fracture walls, followed by crystalline phyllosilicates (smectite), and finishing with a rapidly cooled amorphous silicate gel within the central regions of the fractures. The mesostasis fractures of Lafayette also contain a crystalline phyllosilicate (serpentine). The amorphous gel is the most abundant secondary phase within the fractures of the other nakhlites [1, 2]. By studying nine nakhlite samples, including Lafayette, Governador Valadares, Nakhla, Y-000593, Y-000749, Miller-Range 03346, NWA 817, NWA 998, and NWA 5790, our aim is to constrain the identity of the phyllosilicate secondary phase minerals found throughout the nakhlite martian meteorites. This is achieved using methods including Electron Probe Micro-analysis (EPMA); X-ray Absorption Near-Edge Structure (Fe-K XANES) spectroscopy measured using Beamline I-18 at the Diamond Light Source synchrotron; and the use of Transmission Electron Microscopy (TEM) at the University of Leicester for High-Resolution (HR) imaging and Selected Area Electron Diffraction (SAED). BF studying nine nakhlite samples, including Lafayette, Governador Valadares, Nakhla, Y-000593, Y-000749, Miller-Range 03346, NWA 817, NWA 998, and NWA 5790, our aim is to constrain the identity of the phyllosilicate secondary phase minerals found throughout the nakhlite martian meteorites. This is achieved using methods including Electron Probe Micro-analysis (EPMA); X-ray Absorption Near-Edge Structure (Fe-K XANES) spectroscopy measured using Beamline I-18 at the Diamond Light Source synchrotron; and the use of Transmission Electron Microscopy (TEM) at the University of Leicester for High-Resolution (HR) imaging and Selected Area Electron Diffraction (SAED).

  17. Clotrimazole nanoparticle gel for mucosal administration

    Energy Technology Data Exchange (ETDEWEB)

    Esposito, Elisabetta, E-mail: ese@unife.it [Department of Pharmaceutical Sciences, University of Ferrara, I-44121 Ferrara (Italy); Ravani, Laura [Department of Pharmaceutical Sciences, University of Ferrara, I-44121 Ferrara (Italy); Contado, Catia [Department of Chemistry, University of Ferrara, Ferrara (Italy); Costenaro, Andrea [Department of Pharmaceutical Sciences, University of Ferrara, I-44121 Ferrara (Italy); Drechsler, Markus [Macromolecular Chemistry II, University of Bayreuth (Germany); Rossi, Damiano [Department of Biology and Evolution, LT Terra and Acqua Tech UR7, University of Ferrara, Ferrara (Italy); Menegatti, Enea [Department of Pharmaceutical Sciences, University of Ferrara, I-44121 Ferrara (Italy); Grandini, Alessandro [Department of Biology and Evolution, LT Terra and Acqua Tech UR7, University of Ferrara, Ferrara (Italy); Cortesi, Rita [Department of Pharmaceutical Sciences, University of Ferrara, I-44121 Ferrara (Italy)

    2013-01-01

    In this study a formulation suitable to be applied on oral and/or vaginal mucosa has been developed for the treatment of fungal infections. The aim of the research is a comparison between clotrimazole (CLO) containing semisolid formulations based on monoolein aqueous dispersion (MAD) or nanostructured lipid carrier (NLC). MAD and NLC have been characterized in terms of morphology and dimensional distribution by cryogenic Transmission Electron Microscopy (cryo-TEM) and Photon Correlation Spectroscopy (PCS). CLO was encapsulated with high entrapment efficiency both in MAD and in NLC, according to Sedimentation Field Flow Fractionation (SdFFF) combined with HPLC. CLO recovery in MAD and NLC has been investigated by time. In order to obtain formulations with suitable viscosity for mucosal application, MAD was diluted with a carbomer gel, while NLC was directly viscosized by the addition of poloxamer 407 in the dispersion. The rheological properties of MAD and NLC after viscosizing have been investigated. Franz cell has been employed to study CLO diffusion from the different vehicles, evidencing diffusion rates from MAD and NLC superimposable to that obtained using Canesten{sup Registered-Sign }. An anticandidal activity study demonstrated that both CLO-MAD and CLO-NLC were more active against Candida albicans with respect to the pure drug. Highlights: Black-Right-Pointing-Pointer Comparison between monoolein aqueous dispersion (MAD) and nanostructured lipid carrier (NLC). Black-Right-Pointing-Pointer Clotrimazole (CLO) encapsulated with high entrapment efficiency both in MAD and in NLC. Black-Right-Pointing-Pointer The solid matrix of NLC controls CLO degradation better than MAD. Black-Right-Pointing-Pointer CLO containing MAD and NLC exhibits a higher anticandidal activity than the free drug. Black-Right-Pointing-Pointer Simple production of CLO-NLC based poloxamer gel, suitable for industry scaling up.

  18. Pharmacokinetics of the Protein Microbicide 5P12-RANTES in Sheep following Single-Dose Vaginal Gel Administration.

    Science.gov (United States)

    McBride, John W; Dias, Nicola; Cameron, David; Offord, Robin E; Hartley, Oliver; Boyd, Peter; Kett, Vicky L; Malcolm, R Karl

    2017-10-01

    5P12-RANTES, a chemokine analogue that potently blocks the HIV CCR5 coreceptor, is being developed as both a vaginal and rectal microbicide for prevention of sexual transmission of HIV. Here, we report the first pharmacokinetic data for 5P12-RANTES following single-dose vaginal gel administration in sheep. Aqueous gel formulations containing low (1.24-mg/ml), intermediate (6.18-mg/ml), and high (32.0-mg/ml; suspension-type gel) concentrations of 5P12-RANTES were assessed via rheology, syringeability, and in vitro release testing. Following vaginal gel administration to sheep, 5P12-RANTES concentrations were measured in vaginal fluid, vaginal tissue, and serum over a 96-h period. All gels showed non-Newtonian pseudoplastic behavior, with the high-concentration gels exhibiting a greater viscosity and cohesive structure than the intermediate- and low-concentration gels. In in vitro release testing, >90% 5P12-RANTES was released from the low- and intermediate-concentration gels after 72 h. For the high-concentration gel, ∼50% 5P12-RANTES was detected, attributed to protein denaturation during lyophilization and/or subsequent solvation of the protein within the gel matrix. In sheep, 5P12-RANTES concentrations in vaginal fluid, vaginal tissue, and serum increased in a dose-dependent manner. The highest concentrations were measured in vaginal fluid (10 5 to 10 7 ng/ml), followed by vaginal tissue (10 4 to 10 6 ng/ml). Both of these concentration ranges are several orders of magnitude above the reported half-maximal inhibitory concentrations. The lowest concentration was measured in serum (<10 2 ng/ml). The 5P12-RANTES pharmacokinetic data are similar to those reported previously for other candidate microbicides. These data, coupled with 5P12-RANTES's potency at picomolar concentrations, its strong barrier to resistance, and the full protection that it was observed to provide in a rhesus macaque vaginal challenge model, support the continued development of 5P12-RANTES as

  19. Environmentally benign sol-gel antifouling and foul-releasing coatings.

    Science.gov (United States)

    Detty, Michael R; Ciriminna, Rosaria; Bright, Frank V; Pagliaro, Mario

    2014-02-18

    application, and the waterborne nature of sol-gel coatings all support the diffusion of these paints to efficiently reduce the accumulation of fouling layers on valued surfaces immersed in marine or fluvial waters. Furthermore, sol-gel glassy coatings are transparent and can be effectively applied to optical devices, windows, and solar panels used in lake, fluvial, or marine environments. Sol-gel technology is eminently versatile, and the first generation sol-gel paints have already shown good performance. Even so, vast opportunities still exist for chemists to develop novel sol-gel derived coatings to both prevent biofouling and enhance the hydrodynamic properties of boat and ship hulls. Moreover, researchers have prepared and applied multifunctional sol-gel coatings providing protection against both biofouling and corrosion. They have tested these in the marine environment with good preliminary results. In this Account, we discuss some of our new strategies for the controlled functionalization of surfaces for the development of efficient antifouling and foul-releasing systems and summarize the main achievements with biocidal and nonbiocidal sol-gel coatings. We conclude by giving insight into the marine coatings and sol-gel products markets, providing arguments to justify our conclusion that the sol-gel coatings technology is now a mature platform for the development of economically viable and environmentally friendly antifouling and foul-release formulations of enhanced performance.

  20. Modelling of erosion of bentonite gel by gel/sol flow

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Luis; Neretnieks, Ivars; Longcheng Liu (Chemical Engineering and Technology, School of Chemical Science and Engineering, Royal Institute of Technology, Stockholm (Sweden))

    2010-11-15

    Bentonite intrusion into a fracture intersecting the canister deposition hole is modelled. The model describes the expansion of the bentonite within the fracture. It accounts for the repulsive electrostatic double-layer forces, the attractive van der Waals forces and friction forces between the particles and the water. The model also takes into account the diffusion of the colloid particles in the smectite sol. Diffusion of a counterion, sodium, is accounted for as this strongly influences the double layer force and the viscosity of the gel/sol. The gel/sol is considered to be a fluid with a varying viscosity that is strongly dependent on the bentonite volume fraction in the gel and the sodium concentration in the water. Two different geometries were modelled; a rectangular and a cylindrical. The rectangular geometry was used to gain experience with the processes and mechanisms and how they interact since the cylindrical geometry was somewhat less stable numerically and more time consuming. In the rectangular geometry a fracture 1 metre long in the flow direction was modelled. In both geometries the fracture size was selected sufficiently large to ensure that the water velocity, near the distant border was nearly the same as the approaching water velocity and that the smectite concentration there was vanishingly small. It was found that the velocity of the fluid drops considerably where the bentonite volume fraction is larger than 1-2%. This is due to the strong increase in viscosity with increasing bentonite volume fraction. The loss of smectite by the slowly flowing fluid was found to be proportional to the square root of the seeping water velocity for the rectangular geometry. For the cylindrical geometry, the dependence is somewhat lower (exponent about 0.4) since the length of the gel/water interface decreases with increasing water flow rate. The penetration depth of the gel/water interface decreases with increasing water flow rate. For water velocity of the

  1. Explorative data analysis of two-dimensional electrophoresis gels

    DEFF Research Database (Denmark)

    Schultz, J.; Gottlieb, D.M.; Petersen, Marianne Kjerstine

    2004-01-01

    Methods for classification of two-dimensional (2-DE) electrophoresis gels based on multivariate data analysis are demonstrated. Two-dimensional gels of ten wheat varieties are analyzed and it is demonstrated how to classify the wheat varieties in two qualities and a method for initial screening...

  2. Highly Elastic and Self-Healing Composite Colloidal Gels.

    NARCIS (Netherlands)

    Diba, M.; Wang, H.; Kodger, T.E.; Parsa, S.; Leeuwenburgh, S.C.G.

    2017-01-01

    Composite colloidal gels are formed by the pH-induced electrostatic assembly of silica and gelatin nanoparticles. These injectable and moldable colloidal gels are able to withstand substantial compressive and tensile loads, and exhibit a remarkable self-healing efficiency. This study provides new,

  3. Fast Dissolving Tablets of Aloe Vera Gel | Madan | Tropical Journal ...

    African Journals Online (AJOL)

    Purpose: The objective of this work was to prepare and evaluate fast dissolving tablets of the nutraceutical, freeze dried Aloe vera gel. Methods: Fast dissolving tablets of the nutraceutical, freeze-dried Aloe vera gel, were prepared by dry granulation method. The tablets were evaluated for crushing strength, disintegration ...

  4. Biocatalysis with Sol-Gel Encapsulated Acid Phosphatase

    Science.gov (United States)

    Kulkarni, Suhasini; Tran, Vu; Ho, Maggie K.-M.; Phan, Chieu; Chin, Elizabeth; Wemmer, Zeke; Sommerhalter, Monika

    2010-01-01

    This experiment was performed in an upper-level undergraduate biochemistry laboratory course. Students learned how to immobilize an enzyme in a sol-gel matrix and how to perform and evaluate enzyme-activity measurements. The enzyme acid phosphatase (APase) from wheat germ was encapsulated in sol-gel beads that were prepared from the precursor…

  5. Radiation reaction of skin treatment with nucliderm-gel

    International Nuclear Information System (INIS)

    Pandova, V.; Marinova, Ts.; Stefanova, D.; Pantev, T.; Yankova, S.

    1988-01-01

    The process of epithelization and the anticeptic effect of nucliderm-gel applied locally have been studied in 63 oncological patients subjected to radiotherapy. In all cases under study nucliderm-gel promotes skin epithelization and has a high antiseptic effect as compared with the drugs applied hitherto

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

    Science.gov (United States)

    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.

  7. Preparation of an efficient humidity indicating silica gel from rice ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. An efficient humidity indicating silica gel was prepared using rice husk ash as a raw material via sodium silicate extraction and acid neutralization method. Cobalt chloride was impregnated into the silica gel as a colour indicating material. A low concentration of cobalt chloride solution (0⋅0005 mol dm–3) was used ...

  8. The performance of gel technetium-99m generator

    International Nuclear Information System (INIS)

    Liu Yishu

    2004-01-01

    Technetium-99m, as one of the important radionuclides in nuclear medical science, has been widely used for diseases diagnosis in both developed and developing countries for many years. Technetium-99m can be obtained from both fission-type and gel-type Tc-99m generator. Fission-type generator was prepared by Molybdenum-99 separated from fission products of uranium-235 and gel-type was prepared by irradiating nature MoO 3 in reactor, and a series of chemical and physical processes. This paper briefly describes the manufacturing technical process of gel-type Technetium-99 generator, including the preparation of target containing nature MoO 3 , the target irradiation in reactor, gel preparation, gel filtration and drying, dried gel cracking, generator loading and activity calibration of generator. The performances of gel-type Technetium-99m generator, such as elution efficiency, elution profile, the pH, Mo breakthrough, Zirconium content, radiochemical purity, radionuclidic purity, sterility and pyrogencity of eluate, are also expatiated in detail. Comparing with fission-type Technetium-99m generator, the defects of gel-type Technetium-99m generator are enumerated and their overcoming solutions are recommended in this paper. (author)

  9. Viscoelastic nature of Au nanoparticle–PDMS nanocomposite gels

    Indian Academy of Sciences (India)

    A stable gel of Au nanoparticles in polydimethylsiloxane (PDMS) nanocomposite is prepared by employing the curing agent of PDMS elastomer as a reducing agent for the formation of Au nanoparticles by an in-situ process. The viscoelastic nature of these gels is very sensitive to the Au nanoparticle loading and the ...

  10. Slow Release Of Reagent Chemicals From Gel Matrices

    Science.gov (United States)

    Debnam, William J.; Barber, Patrick G.; Coleman, James

    1988-01-01

    Procedure developed for slow release of reagent chemicals into solutions. Simple and inexpensive and not subject to failure of equipment. Use of toothpaste-type tube or pump dispenser conceivably provides more controlled technique for storage and dispensation of gel matrix. Possible uses include controlled, slow release of reagents in chemical reactions, crystal growth, space-flight experiments, and preformed gel medications from packets.

  11. Starch gel electrophoresis of conifer seeds: a laboratory manual

    Science.gov (United States)

    M. Thompson Conkle; Paul D. Hodgskiss; Lucy B. Nunnally; Serena C. Hunter

    1982-01-01

    This manual describes fast, low-cost biochemical procedures for separating enzymes representing numerous genes of forest trees. During electrophoresis the mixture of enzymes from a megagametophyte or embryo of a germinated seed separates in a gel. Specific stains applied to gel slices locate each enzyme. These procedures expand on those developed for crops research....

  12. Self-Healing Corrosion Protective Sol-Gel Coatings

    NARCIS (Netherlands)

    Abdolah Zadeh, M.

    2016-01-01

    Inspired by the state of the art and the recent advances in the field of self-healing corrosion protective coatings, the thesis entitled “Self-healing corrosion protective sol-gel coatings” addresses novel routes to self-healing corrosion protective sol-gel coatings via extrinsic and intrinsic

  13. Recovery of DNA from agarose gel by trap method

    African Journals Online (AJOL)

    Administrator

    2011-09-05

    Sep 5, 2011 ... target band and refilling it with the same buffer. When the molecules of DNA move from agarose gel into a well, the velocity of DNA will increase in the well without interaction between gel and DNA (Stellwagen and. Stellwagen, 2009). It is possible to recover them from the. *Corresponding author. E-mail: ...

  14. Rheological properties of soybean protein isolate gels containing emulsion droplets

    NARCIS (Netherlands)

    Kim, K.H.; Renkema, J.M.S.; Vliet, van T.

    2001-01-01

    Rheological properties of soybean protein gels containing various volume fractions oil droplets have been studied at small and large deformations. Dynamic viscoelastic properties of soybean protein isolate gels were determined as a function of the volume fraction of oil droplets stabilised by the

  15. Inexpensive and Safe DNA Gel Electrophoresis Using Household Materials

    Science.gov (United States)

    Ens, S.; Olson, A. B.; Dudley, C.; Ross, N. D., III; Siddiqi, A. A.; Umoh, K. M.; Schneegurt, M. A.

    2012-01-01

    Gel electrophoresis is the single most important molecular biology technique and it is central to life sciences research, but it is often too expensive for the secondary science classroom or homeschoolers. A simple safe low-cost procedure is described here that uses household materials to construct and run DNA gel electrophoresis. Plastic…

  16. Electrical conductivity measurements on gel grown KDP crystals ...

    Indian Academy of Sciences (India)

    Unknown

    †Scott Christian College, Nagercoil 629 003, India. MS received 4 September 2000; revised 16 July 2001. Abstract. Pure and impurity added (with urea and thiourea) KDP single crystals were grown by the gel method using silica gels. Electrical conductivity measurements were carried out along both the unique axis and.

  17. 3D Architectured polyazomethine gel synthesis: its self-assembled ...

    Indian Academy of Sciences (India)

    2018-03-28

    Mar 28, 2018 ... Abstract. Azomethine is the key linkage in all Schiff base reactions. The present context has efficiently emphasized on the utilization of Schiff base strategy effectively in the synthesis of polyazomethine polymer gel materials. The synthesized polymer gel is characterized by different physical techniques for ...

  18. Electrochemical behavior of ionically crosslinked polyampholytic gel electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wanyu; Tang, Haitao; Ou, Ziwei; Wang, Hong; Yang, Yajiang [Department of Chemistry, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2007-12-31

    An ionic complex of anionic and cationic monomers was obtained by protonation of (N,N-diethylamino)ethylmethacrylate (DEA) with acrylic acid (AAc). Free radical copolymerization of the ionic complex and acrylamide (AAm), yielded the ionically crosslinked polyampholytic gel electrolytes [poly(AAc-DEA-AAm), designated as PADA] using two types of organic solvents containing a lithium salt. The PADA gel electrolyte exhibited good thermal stability shown by the DSC thermogram. The impedance analysis at temperatures ranging from -30 to 75 C indicated that the ionic conductivities of the PADA gel electrolytes were rather close to those of liquid electrolytes. The temperature dependence of the ionic conductivities was found to be in accord with the Arrhenius equation. Moreover, the ionic conductivities of PADA gel electrolytes increased with an increase of the molar ratios of cationic/anionic monomers. The ionic conductivities of PADA gels prepared in solvent mixtures of propylene carbonate, ethyl methyl ether and dioxolane (3:1:1, v/v) were higher than those of PADA gels prepared in propylene carbonate only. Significantly, the ionic conductivities of two kinds of PADA gel electrolytes were in the range of 10{sup -3} and 10{sup -4} S cm{sup -1} even at -30 C. The electrochemical windows of PADA gel electrolytes measured by cyclic voltammetry were in the range from -1 V to 4.5 V. (author)

  19. Electrochemical behavior of ionically crosslinked polyampholytic gel electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Chen Wanyu; Tang Haitao; Ou Ziwei; Wang Hong [Department of Chemistry, Huazhong University of Science and Technology, Wuhan 430074 (China); Yang Yajiang [Department of Chemistry, Huazhong University of Science and Technology, Wuhan 430074 (China)], E-mail: yjyang@mail.hust.edu.cn

    2007-12-31

    An ionic complex of anionic and cationic monomers was obtained by protonation of (N,N-diethylamino)ethylmethacrylate (DEA) with acrylic acid (AAc). Free radical copolymerization of the ionic complex and acrylamide (AAm), yielded the ionically crosslinked polyampholytic gel electrolytes [poly(AAc-DEA-AAm), designated as PADA] using two types of organic solvents containing a lithium salt. The PADA gel electrolyte exhibited good thermal stability shown by the DSC thermogram. The impedance analysis at temperatures ranging from -30 to 75 deg. C indicated that the ionic conductivities of the PADA gel electrolytes were rather close to those of liquid electrolytes. The temperature dependence of the ionic conductivities was found to be in accord with the Arrhenius equation. Moreover, the ionic conductivities of PADA gel electrolytes increased with an increase of the molar ratios of cationic/anionic monomers. The ionic conductivities of PADA gels prepared in solvent mixtures of propylene carbonate, ethyl methyl ether and dioxolane (3:1:1, v/v) were higher than those of PADA gels prepared in propylene carbonate only. Significantly, the ionic conductivities of two kinds of PADA gel electrolytes were in the range of 10{sup -3} and 10{sup -4} S cm{sup -1} even at -30 deg. C. The electrochemical windows of PADA gel electrolytes measured by cyclic voltammetry were in the range from -1 V to 4.5 V.

  20. Electrical conductivity measurements on gel grown KDP crystals ...

    Indian Academy of Sciences (India)

    2CO3 and (NH4)2SO4] KDP sin- gle crystals were grown by the gel method using silica gels. Electrical conductivity measurements were carried out along both the unique axis and perpendicular directions at various temperatures ranging from 28 ...