Sealants in dentistry: outcomes of the ORCA saturday afternoon symposium 2007

NARCIS (Netherlands)

Splieth, C.H.; Ekstrand, K.R.; Alkilzy, M.; Clarkson, J.; Meyer-Lueckel, H.; Martignon, S.; Paris, S.; Pitts, N.B.; Rickets, D.N.; van Loveren, C.

2010-01-01

Sealants are a successful tool in caries prevention, but their role in preventive strategies after the caries decline has to be discussed. A survey of paediatric departments across Europe revealed that indications for pit and fissure sealants vary considerably, both nationally and internationally.

Sealants in dentistry: outcomes of the ORCA Saturday Afternoon Symposium 2007

DEFF Research Database (Denmark)

Splieth, C H; Ekstrand, K R; Alkilzy, M

2009-01-01

Sealants are a successful tool in caries prevention, but their role in preventive strategies after the caries decline has to be discussed. A survey of paediatric departments across Europe revealed that indications for pit and fissure sealants vary considerably, both nationally and internationally...

Systematic review on the use of matrix-bound sealants in pancreatic resection.

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Smits, F Jasmijn; van Santvoort, Hjalmar C; Besselink, Marc G H; Borel Rinkes, Inne H M; Molenaar, I Quintus

2015-11-01

Pancreatic fistula is a potentially life-threatening complication after a pancreatic resection. The aim of this systematic review was to evaluate the role of matrix-bound sealants after a pancreatic resection in terms of preventing or ameliorating the course of a post-operative pancreatic fistula. A systematic search was performed in the literature from May 2005 to April 2015. Included were clinical studies using matrix-bound sealants after a pancreatic resection, reporting a post-operative pancreatic fistula (POPF) according to the International Study Group on Pancreatic Fistula classification, in which grade B and C fistulae were considered clinically relevant. Two were studies on patients undergoing pancreatoduodenectomy (sealants n = 67, controls n = 27) and four studies on a distal pancreatectomy (sealants n = 258, controls n = 178). After a pancreatoduodenectomy, 13% of patients treated with sealants versus 11% of patients without sealants developed a POPF (P = 0.76), of which 4% versus 4% were clinically relevant (P = 0.87). After a distal pancreatectomy, 42% of patients treated with sealants versus 52% of patients without sealants developed a POPF (P = 0.03). Of these, 9% versus 12% were clinically relevant (P = 0.19). The present data do not support the routine use of matrix-bound sealants after a pancreatic resection, as there was no effect on clinically relevant POPF. Larger, well-designed studies are needed to determine the efficacy of sealants in preventing POPF after a pancreatoduodenectomy. © 2015 International Hepato-Pancreato-Biliary Association.

Use of sealants: societal and professional factors.

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Frazier, P J

1984-02-01

At present, sealant use continues at a low level in private practice by dentists and hygienists, and is moderate in community programs although there is high interest in their use in public health settings. Widespread delegation of sealant application to hygienists has not occurred even though the majority of state dental practice acts allow it, and even though practicing hygienists are highly interested in applying sealants. Use in federally sponsored programs is minimal or nonexistent. Information about sealants and adequate clinical experience in their application appear minimal in dental training institutions, and few opportunities have existed for continuing education. Generally, knowledge about sealants among dentists is low; many hold doubtful opinions. Insurance carriers, including commercial, provider, and governmental programs, appear reluctant to reimburse for sealants without purchaser demand and organized dentistry's blessings. Although society emphasizes patient rights to informed consent, few opportunities exist for the public, including group insurance purchasers and union negotiators, to learn about sealant use in conjunction with appropriate fluoride use. Public educational materials are sparse. Manufacturer marketing efforts at present, aimed at providers alone, are at best minimal, with a few exceptions; those targeting the public are nonexistent. Organized dentistry's Council statements may have contributed to a constriction, to date, in the flow of public information about sealants from industry. Lack of communication, or miscommunication, between practitioners and dental scientists has resulted in much misinformation and confusion about the value of sealants and their use. And, the contemporary status of dental manpower and the economy of dental practice in the private sector appear to have provided an infertile environment for acceptance of sealants as a primary preventive technology. In the public sector, interest in sealants is high but

Evaluation of a sealant intervention program among Taiwanese aboriginal schoolchildren

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Hui-Ju Hsieh

2014-06-01

Conclusion: The application of pit-and-fissure sealants was 94.54% effective in preventing caries on newly erupted permanent molars among Taiwanese aboriginal schoolchildren. Complete sealant failure demonstrated a high risk for caries, and such teeth should immediately be resealed.

Fissure sealants in caries prevention:a practice-based study using survival analysis

OpenAIRE

Leskinen, K. (Kaja)

2010-01-01

Abstract The purpose of this study was to analyse the effectiveness and cost of fissure sealant treatment in preventing dental caries in children in a practice-based research network using survival analysis. The survival times of first permanent molars in children were analysed in three countries: in Finland (age cohorts 1970–1972 and 1980–1982), in Sweden (1980–1982) and in Greece (1980–1982), and additionally at two municipal health centres in Finland (age cohorts 1988–1990 in Kemi...

PERBEDAAN TOPICAL FLUORIDE APPLICATION DAN FISSURE SEALANT DALAM MENCEGAH KARIES PADAGIGI MOLAR SATU

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Pawarti Pawarti

2017-07-01

Full Text Available Abstract: Topical Fluoride Application And Fissure Sealant To Prevent Dental Caries Permanent First Molars. Anatomy pits and fissures of teeth are caries initiation vulnerable areas of the permanent molars that grow at the age of 6 years where children can not perform oral hygiene. Caries prevention can be done by closing the pits and fissures or application of fluoride (topical fluoride application on the surface of the teeth. The purpose of this study was to analyze the difference fissure sealants and topical application of fluoride to prevent dental caries of first permanent molars. This study was a quasi-experimental study with time series, a sample was taken by purposive 117-second grade students of SDN District of North Pontianak. Data were analyzed using t-test. The result showed that fissure sealant more effective in caries prevention of first permanent molar than topical fluoride application where there were none caries teeth after and month fissure sealant, 25% sealant partially off and 11% fully off. Teeth that have done fluoride after 6 months of 3.9% of dental caries, the eighth month of 5.4% of dental caries. There was a significant difference between the effectiveness of fissure sealants with topical application of fluoride to prevent dental caries in first permanent molars p-value < 0.05, after 6-month p-value: 0.004 and after 8-month p-value: 0.001. Abstrak: Topical Fluoride Application Dan Fissure Sealant Untuk Mencegah Karies Pada Gigi Molar Satu Permanen. Anatomi pit dan fisura gigi merupakan daerah rentan inisiasi karies gigi molar satu permanen yang tumbuh pada usia 6 tahun anak belum bisa melakukan kebersihan mulutnya. Pencegahan karies dapat dilakukan dengan cara menutup pit dan fissure atau pengolesan fluor (topical fluoride application pada permukaan gigi. Tujuan penelitian ini untuk menganalisis perbedaan efektivitas fissure sealant dan topical fluoride application untuk mencegah karies gigi molar satu permanen anak

Effect of Adhesive Application on Sealant Success: A Clinical Study of Fifth and Seventh Generation Adhesive Systems

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Vaibhav Tandon

2016-03-01

Full Text Available Objectives: The aim of the study was to compare the effect of fifth and seventh generation bonding agent on sealant success.Materials and Methods: Sixty-four school children aged six to nine years received sealants in four permanent molars in a split mouth design, such that each patient received sealant in the first permanent molar with fifth generation bonding agent in one arch and seventh generation bonding agent in the other arch; contra-lateral molars were sealed with sealant alone. The evaluation was carried out at baseline, three months, six months and 12 months, according to the criteria by Feigal et al, in 2000. Chi- square test was used to analyze data at P<0.05 level of significance.Results: Statistically significant differences were found for sealant retention between fifth generation and sealant group, and fifth generation and seventh generation groups; whereas, no significant difference was found for sealant retention between seventh generation and sealant group at three, six and 12 months.Conclusion: As separate etch and rinse steps are not required for seventh generation bonding agents, and almost similar results were obtained for both sealant and seventh generation groups, it can be concluded that application of sealant along with a seventh generation bonding agent may enhance sealant success and can be used for caries prevention in preventive programs.Key words:  Pit and Fissure Sealants; Dental Caries; Adhesives

Clinical and SEM assessment of ART high-viscosity glass-ionomer sealants after 8-13 years in 4 teeth.

NARCIS (Netherlands)

Frencken, J.E.F.M.; Wolke, J.G.C.

2010-01-01

OBJECTIVES: Resin composite sealants are retained longer than low-viscosity glass-ionomer sealants. Nevertheless, a systematic review showed that there is no evidence that resin composite sealants are superior to low-viscosity glass-ionomers in preventing dentine carious lesion development. This

Effectiveness of fluoride sealant in the prevention of carious lesions around orthodontic brackets: an OCT evaluation

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Pithon, Matheus Melo; Santos, Mariana de Jesus; de Souza, Camilla Andrade; Leão, Jorge César Borges; Braz, Ana Karla Souza; de Araujo, Renato Evangelista; Tanaka, Orlando Motohiro; Oliveira, Dauro Douglas

2015-01-01

Abstract Objective: This article aimed to evaluate in vitro the efficiency of Pro Seal fluoride sealant application in the prevention of white spot lesions around orthodontic brackets. Material and Methods: Brackets were bonded to the buccal surface of bovine incisors, and five groups were formed (n = 15) according to the exposure of teeth to oral hygiene substances and the application of enamel sealant: G1 (control), only brushing was performed with 1.450 ppm fluoride; G2 (control) brushing associated with the use of mouthwash with 225 ppm fluoride; G3, only Pro Seal sealant application was performed with 1.000 ppm fluoride; G4 Pro Seal associated with brushing; G5 Pro Seal associated with brushing and mouthwash. Experimental groups alternated between pH cycling and the procedures described. All specimens were kept at a temperature of 37 °C throughout the entire experiment. Both brushing and immersion in solutions were performed within a time interval of one minute, followed by washing in deionized water three times a day for 28 days. Afterwards, an evaluation by Optical Coherence Tomography (OCT) of the spectral type was performed. In each group, a scanning exam of the white spot lesion area (around the sites where brackets were bonded) and depth measurement of carious lesions were performed. Analysis of variance (ANOVA) was applied to determine whether there were significant differences among groups. For post hoc analysis, Tukey test was used. Results: There was statistically significant difference between groups 1 and 2 (p = 0.003), 1 and 3 (p = 0.008), 1 and 4 (p = 0.000) and 1 and 5 (p = 0.000). The group in which only brushing was performed (Group 1) showed deeper enamel lesion. Conclusion: Pro Seal sealant alone or combined with brushing and/or brushing and the use of a mouthwash with fluoride was more effective in protecting enamel, in comparison to brushing alone. PMID:26691968

Vital Signs: Dental Sealant Use and Untreated Tooth Decay Among U.S. School-Aged Children.

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Griffin, Susan O; Wei, Liang; Gooch, Barbara F; Weno, Katherine; Espinoza, Lorena

2016-10-21

Tooth decay is one of the greatest unmet treatment needs among children. Pain and suffering associated with untreated dental disease can lead to problems with eating, speaking, and learning. School-based dental sealant programs (SBSP) deliver a highly effective intervention to prevent tooth decay in children who might not receive regular dental care. SBSPs benefits exceed their costs when they target children at high risk for tooth decay. CDC used data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014 to estimate current prevalences of sealant use and untreated tooth decay among low-income (≤185% of federal poverty level) and higher-income children aged 6-11 years and compared these estimates with 1999-2004 NHANES data. The mean number of decayed and filled first molars (DFFM) was estimated for children with and without sealants. Averted tooth decay resulting from increasing sealant use prevalence was also estimated. All reported differences are significant at pdental sealant use has increased; however, most children have not received sealants. Increasing sealant use prevalence could substantially reduce untreated decay, associated problems, and dental treatment costs.

Evaluation of a hydrophilic gingival dental sealant in beagle dogs.

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Sitzman, Clarence

2013-01-01

A liquid solution, gingival sealant containing polymers that form a barrier film upon application was evaluated in dogs. It is a non-toxic, low viscosity, hydrophilic barrier sealant that dries in approximately 10 to 15-seconds after subgingival application. It was designed as a preventative to be applied immediately following a professional oral hygiene procedure in order to block plaque and calculus formation in the sulcus and aid in the prevention of periodontal disease in companion animals. Additionally, the polymer was designed to promote an aerobic environment in the sulcus by oxygen and water transport through engineered pores within the polymer. A 30-day split-mouth, blinded study in two groups of 15 beagle dogs was used. Plaque was significantly (p periodontal disease in dogs.

Parametric Study of Sealant Nozzle

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Yamamoto, Yoshimi

It has become apparent in recent years the advancement of manufacturing processes in the aerospace industry. Sealant nozzles are a critical device in the use of fuel tank applications for optimal bonds and for ground service support and repair. Sealants has always been a challenging area for optimizing and understanding the flow patterns. A parametric study was conducted to better understand geometric effects of sealant flow and to determine whether the sealant rheology can be numerically modeled. The Star-CCM+ software was used to successfully develop the parametric model, material model, physics continua, and simulate the fluid flow for the sealant nozzle. The simulation results of Semco sealant nozzles showed the geometric effects of fluid flow patterns and the influences from conical area reduction, tip length, inlet diameter, and tip angle parameters. A smaller outlet diameter induced maximum outlet velocity at the exit, and contributed to a high pressure drop. The conical area reduction, tip angle and inlet diameter contributed most to viscosity variation phenomenon. Developing and simulating 2 different flow models (Segregated Flow and Viscous Flow) proved that both can be used to obtain comparable velocity and pressure drop results, however; differences are seen visually in the non-uniformity of the velocity and viscosity fields for the Viscous Flow Model (VFM). A comprehensive simulation setup for sealant nozzles was developed so other analysts can utilize the data.

Comparison of Caries Prevention With Glass Ionomer and Composite Resin Fissure Sealants

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Aylin Akbay Oba

2009-11-01

Conclusion: Under field conditions in which moisture control was not effective, a high-viscosity and less technique-sensitive glass ionomer material can be used as an effective sealant material, rather than resin.

Effectiveness of Dry Cow Therapy Comprising Antibiotic Treatment, Internal Teat Sealant, and α-Tocopherol Against New Intramammary Infections in Cows

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Cengiz Mehmet

2015-04-01

Full Text Available The aim of this study was to evaluate the preventive effectiveness of dry cow therapy based on antibiotic, internal teat sealant, and α-tocopherol administered separately or in various combinations at drying-off The study was performed on 322 uninfected quarters of 95 cows originating from three dairy herds. The new intramammary infection rates after calving were measured to evaluate the effectiveness. The quarters were divided into six groups differing in treatment, namely: control group (group C, n = 40 and five treatment groups. Treatment groups were arranged as follows: group A (antibiotic alone, n = 81, group AS (antibiotic + sealant, n = 40, group AST (antibiotic + sealant + α-tocopherol, n = 40, group T (α-tocopherol alone, n = 40, group S (sealant alone, n = 81. New infection rate amounted to 47.5% in group C. The treatment in group AST significantly prevented from the occurrence of new intramammary infections (12.5%, P 0.05, although the use of the sealant alone (group S decreased the risk of new infection (24.7%, P 0.05. Increased α-tocopherol level (P < 0.05 was detected after calving in the quarters from cows that received α-tocopherol injections. In conclusion, the combination of antibiotic, internal teat sealant, and α-tocopherol used in dry cow therapy showed a significantly better preventive effect against new intramammary infections, than the therapeutics administered separately.

Durability of sealants exposed to outdoor weathering and hot compression cycles

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Gregory T. Schueneman; Steven Lacher; Christopher G. Hunt; Christopher C. White; Donald L. Hunston

2011-01-01

Sealants play an important role in weatherproofing structures by filling gaps and preventing air and water intrusion. When incorrectly selected or improperly applied, they may fail quickly, compromising durability of the structure. To ensure reliability and prevent the need for costly repairs to structures, it is necessary to measure durability and predict life...

Use of a sealant to prevent prolonged air leaks after lung resection: a prospective randomized study.

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Lequaglie, Cosimo; Giudice, Gabriella; Marasco, Rita; Morte, Aniello Della; Gallo, Massimiliano

2012-10-08

Pulmonary air leaks are common complications of lung resection and result in prolonged hospital stays and increased costs. The purpose of this study was to investigate whether, compared with standard care, the use of a synthetic polyethylene glycol matrix (CoSeal®) could reduce air leaks detected by means of a digital chest drain system (DigiVent™), in patients undergoing lung resection (sutures and/or staples alone). Patients who intraoperatively showed moderate or severe air leaks (evaluated by water submersion tests) were intraoperatively randomized to receive just sutures/staples (control group) or sutures/staples plus CoSeal® (sealant group). Differences among the groups in terms of air leaks, prolonged air leaks, time to chest tube removal, length of hospital stay and related costs were assessed. In total, 216 lung resection patients completed the study. Nineteen patients (18.1%) in the control group and 12 (10.8%) patients in the sealant group experienced postoperative air leaks, while a prolonged air leak was recorded in 11.4% (n=12) of patients in the control group and 2.7% (n=3) of patients in the sealant group. The difference in the incidence of air leaks and prolonged air leaks between the two groups was statistically significant (p=0.0002 and p=0.0013). The mean length of hospital stay was significantly shorter in the sealant group (4 days) than the control group (8 days) (p=0.0001). We also observed lower costs in the sealant group than the control group. The use of CoSeal® may decrease the occurrence and severity of postoperative air leaks after lung resection and is associated with shorter hospital stay. Not registered. The trial was approved by the Institutional Review Board of the IRCCS-CROB Basilicata Regional Cancer Institute, Rionero in Vulture, Italy.

Prevalence of sealants in relation to dental caries on the permanent molars of 12 and 15-year-old Greek adolescents. A national pathfinder survey

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Mamai-Homata Eleni

2011-02-01

Full Text Available Abstract Background The use of sealants as an effective measure for the prevention of pit and fissure caries in children has been well documented by several studies; either they are used on an individual or on a public health basis. In order to plan and establish a national preventive program with sealants in a community, it is mandatory to know the epidemiological pattern of caries along with other variables influencing their use and effectiveness. Aims: To assess the utilization and distribution pattern of pit and fissure sealants on the first and second permanent molars of Greek adolescents and to evaluate whether the existing usage of sealants and some socio-demographic factors are correlated to caries prevalence on the population examined Methods A stratified cluster sample of 2481 Greek adolescents was selected according to WHO guidelines (1224 twelve and 1,257 fifteen-year-old, living in urban and rural areas in 11 districts within the country. Five calibrated examiners carried out clinical examinations, recording caries experience at the dentine threshold (BASCD criteria and presence or absence of sealants along with Socio-demographic indicators associated with oral health. Mann Whitney and Pearson's chi-square non parametric tests were utilized for assessing the data. The level of significance was p Results Sealants utilization varied considerably within the different districts, with 8,3% of the 12 and 8,0% of the 15-year-old adolescents having at least one sealed molar. Sealants reduced DMFS scores by 11% in the 12-year-olds and by 24% in the 15-year-olds, while 15-year-old adolescents from rural areas had a statistically significant (p = 0.002 less chance of having sealants (71% compared to children from urban areas. Girls had higher chance to receive sealants in both age groups (26% for the 12 and 19% for the 15-year-old as well as patients that visited the dentist for prevention compared to those visiting the dentist because they

Comparison of a plasma-based composite biologic sealant with fibrin glue (Tisseel) for vascular anastomoses.

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Doillon, Charles J; Dion, Yves-Marie

2004-12-01

Biologic sealants are needed in numerous, more and more demanding, procedures--especially with developments occurring in endovascular and laparoscopic vascular techniques. An initial pilot study in dogs showed that a 4-cm aortotomy closed with a polyester patch sutured in place by a 4-mm-spaced running suture consistently led to massive hemorrhage. We then designed a study using five dogs where two aortotomies were done to compare the effect of Tisseel to that of an autologous sealant prepared in our laboratory. Arterial pressures and heparinization were maintained throughout the surgical procedure. Both biologic sealants prevented hemorrhage from the arteriotomy at unclamping. Macroscopic and histologic assessments were performed. At killing, one week later, the autologous sealant exhibited less blood saturation of the collagen sponge compared with Tisseel. The use of autologous plasma combined with other adhesive components could be an efficient alternative to allogenic fibrin glue. Further studies are needed to confirm these observations.

Durability of building joint sealants

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Christopher C. White; Kar Tean Tan; Donald L. Hunston; R. Sam Williams

2009-01-01

Predicting the service life of building joint sealants exposed to service environments in less than real time has been a need of the sealant community for many decades. Despite extensive research efforts to design laboratory accelerated tests to duplicate the failure modes occurring in field exposures, little success has been achieved using conventional durability...

Survival of sealants in molars affected by molar-incisor hypomineralization: 18-month follow-up

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Camila Maria Bullio FRAGELLI

2017-04-01

Full Text Available Abstract The objective of this study was to evaluate the clinical survival of sealants applied in first permanent molars (FPMs affected by molar-incisor hypomineralization (MIH, at 18 months of follow-up. Forty-one first permanent molars were selected from 21 children, 6–8 years of age. MIH was classified by one calibrated examiner (kappa = 0.80 according to EAPD criteria. The inclusion criteria were fully erupted FPMs with MIH or sound FPMs (without MIH for which sealant treatment was indicated. The FPMs were assigned to two groups: CG (control group and HG (MIH group. Both groups were treated with sealant (FluroShield. Clinical follow-up was performed from baseline to 18 months to assess anatomical form, marginal adaptation, retention and presence of caries, according to criteria set by the United States Public Health Service-Modified, and was conducted by a blinded examiner (kappa = 0.80. The actuarial method was used to evaluate the survival of the sealants. The survival rates for the groups were compared using Fisher’s exact test (α = 5%. The cumulative survival rates were 81% at 1 month, 68.8% at 6 months, 68.8% at 12 months, and 62.6% at 18 months for CG, and 88% at 1 month, 84% at 6 months, 76% at 12 months, and 72% at 18 months for HG. No significant difference was found between the groups. The sealants in molars affected by MIH presented a survival rate similar to the sealants in the control, suggesting that sealants may be an adequate approach for preventing carious lesions in MIH-affected molars.

Use of a sealant to prevent prolonged air leaks after lung resection: a prospective randomized study

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Lequaglie Cosimo

2012-10-01

Full Text Available Abstract Background Pulmonary air leaks are common complications of lung resection and result in prolonged hospital stays and increased costs. The purpose of this study was to investigate whether, compared with standard care, the use of a synthetic polyethylene glycol matrix (CoSeal® could reduce air leaks detected by means of a digital chest drain system (DigiVent™, in patients undergoing lung resection (sutures and/or staples alone. Methods Patients who intraoperatively showed moderate or severe air leaks (evaluated by water submersion tests were intraoperatively randomized to receive just sutures/staples (control group or sutures/staples plus CoSeal® (sealant group. Differences among the groups in terms of air leaks, prolonged air leaks, time to chest tube removal, length of hospital stay and related costs were assessed. Results In total, 216 lung resection patients completed the study. Nineteen patients (18.1% in the control group and 12 (10.8% patients in the sealant group experienced postoperative air leaks, while a prolonged air leak was recorded in 11.4% (n = 12 of patients in the control group and 2.7% (n = 3 of patients in the sealant group. The difference in the incidence of air leaks and prolonged air leaks between the two groups was statistically significant (p = 0.0002 and p = 0.0013. The mean length of hospital stay was significantly shorter in the sealant group (4 days than the control group (8 days (p = 0.0001. We also observed lower costs in the sealant group than the control group. Conclusion The use of CoSeal® may decrease the occurrence and severity of postoperative air leaks after lung resection and is associated with shorter hospital stay. Trial registration Not registered. The trial was approved by the Institutional Review Board of the IRCCS-CROB Basilicata Regional Cancer Institute, Rionero in Vulture, Italy.

Dental Sealants

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... that protect the chewing surfaces of children’s back teeth from tooth decay. Overall, the prevalence of sealants in children’s and adolescent’s teeth has increased since the early 1970s. In spite ...

Microleakage, adaptation ability and clinical efficacy of two fluoride releasing fissure sealants

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Marković Dejan

2012-01-01

Full Text Available Background/Aim. Retention of fissure sealants and good adaptation to enamel are essential for their success. Fluoride releasing resin-based materials are widely accepted for pit and fissure sealing, but newly designed glass ionomers can serve as a good alternative. The aim of this study was to evaluate microleakage and sealing ability in vitro, and to clinically assess two fluoride releasing fissure sealants. Methods. The sample for experimental study consisted of 20 freshly extracted intact human third molars, divided in two experimental groups according to the sealing material: fluoride releasing resin-based (Heliosel F and glass ionomer (Fuji Triage material. Digital images and scanning electron microscope were used to assess microleakage and adaptation ability. Sample for clinical study consisted of 60 children, aged 6-8 years, with high caries risk, divided in two groups according to the sealant material. Fissure sealant was applied to all erupted, caries-free first permanent molars. Sealants were evaluated after 3, 6 and 12 months using modified Ryge criteria for retention, marginal adaptation, colour match, surface smoothness and caries. Results. Microleakage was detected in more than half of the specimen, without significant differences between the two groups (p > 0.05. Both materials exhibited acceptable sealing ability. Complete retention at the end of the observation period was 81.8% for resin-based, and 21.1% for glass-ionomer fissure sealant (p < 0.001. The presence of caries in sealed molars has been detected in one patient in both groups. During the 12-month observation period, Helioseal F demonstrated better retention, marginal adaptation and surface smoothness (p < 0.001. There were no differences between the two materials regarding caries and color match (p > 0.05. Conclusion. Both tested materials demonstrate satisfactory clinical and caries prophylactic characteristics that justify their use in contemporary preventive

Silver microparticles plus fibrin tissue sealant prevents incisional hernias in rats.

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Primus, Frank E; Young, David M; Grenert, James P; Harris, Hobart W

2018-07-01

Open abdominal surgery is frequently complicated by the subsequent development of an incisional hernia. Consequently, more than 400,000 incisional hernia repairs are performed each year, adding over $15 billion per year to U.S. health-care expenditures. While the vast majority of studies have focused on improved surgical techniques or prosthetic materials, we examined the use of metallic silver microparticles to prevent incisional hernia formation through enhanced wound healing. A rodent incisional hernia model was used. Eighty-two rats were randomly placed into two control groups (saline alone and silver microparticles alone), and three experimental groups (0 mg/cm, 2.5 mg/cm, and 25 mg/cm of silver microparticles applied with a fibrin sealant). Incisional hernia incidence and size, tensile strength, and tissue histology were assessed after 28 days. A significant reduction of both incisional hernia incidence and hernia size was observed between the control groups and 2.5 mg/cm group, and between the control and 25 mg/cm group by nearly 60% and 90%, respectively (P < 0.05). Histological samples showed a noticeable increase in new fibrosis in the treated animals as compared with the controls, whereas the tensile strength between the groups did not differ. The novel approach of using silver microparticles to enhance wound healing appears to be a safe and effective method to prevent incisional hernias from developing and could herald a new era of medicinal silver use. Copyright © 2018 Elsevier Inc. All rights reserved.

Do light cured ART conventional high-viscosity glass-ionomer sealants perform better than resin-composite sealants: a 4-year randomized clinical trial

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Zhang, W.; Chen, X.; Fan, M.W.; Mulder, J.; Huysmans, M.C.D.N.J.M.; Frencken, J.E.F.M.

2014-01-01

OBJECTIVE: The hypotheses tested were: the cumulative survival rates of dentin caries lesion-free pits and fissures of ART conventional high-viscosity glass-ionomer sealants with light-curing (high-intensity LED) and glass-carbomer sealants are higher than those of conventional ART sealants and

Characterization of low temperature creep properties of crack sealants using bending beam rehometry.

Science.gov (United States)

2009-11-01

Crack sealing has been widely used as a routine preventative maintenance practice. Given its proper installation, crack sealants can extend : pavement service life by three to five years. However, current specifications for the selection of crack sea...

Retention of fissure sealants using two different methods of application in teeth with hypomineralised molars (MIH): a 4 year clinical study.

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Lygidakis, N A; Dimou, G; Stamataki, E

2009-12-01

This was to evaluate the retention rate of fissure sealants applied to MIH molars with occlusal enamel opacities, using two different application methods after 4 years. 54 children exhibiting molars with MIH aged 6-7 years, participated in the study. presence of at least 2 fully erupted caries-free maxillary or mandibular first permanent molars in the opposite sides of the mouth, both with occlusal enamel opacities without breakdown. Following parental consent, sealants were applied using a half-mouth experimental design. Group A: On a randomly assigned first molar on one side of the mouth sealants Fissurit were placed using a single bottle adhesive system (One-step prior to sealant application. Group B: Sealants were applied on the contra-lateral molar using the conventional etch and seal technique. Children were seen biannually when a preventive program was applied, without replacing any lost sealant. After 4 years, 47 sets of molars (94 teeth) were available for blind evaluation. Teeth in Group A presented a better retention rate; 70.2% were fully sealed, 29.7% partly sealed and none unsealed (lost sealant). Group B revealed 25.5% fully sealed, 44.6% partly sealed and 29.7% unsealed teeth. Differences between groups A and B were statistically significant (p0.01). In hypomineralised molars with occlusal opacities sealants appear to have greater retention when applied using 5th generation adhesive systems prior to sealant.

Bond Strength of a Bisphenol-A-Free Fissure Sealant With and Without Adhesive Layer under Conditions of Saliva Contamination.

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Mesquita-Guimarães, Késsia Suênia Fidelis de; Sabbatini, Iliana Ferraz; Almeida, Cintia Guimarães de; Galo, Rodrigo; Nelson-Filho, Paulo; Borsatto, Maria Cristina

2016-01-01

Dental sealants are important for prevention of carious lesions, if they have good shear strength. The aim of this study was to evaluate the shear bond strength (SBS) of two sealants to saliva-contaminated and non-contaminated enamel with and without an intermediate adhesive layer underneath the sealant. Ninety flat enamel surfaces from human third molars were randomly assigned to 6 groups (n=15): F (control): Fluroshield(tm) sealant; EWB (control): Embrace(tm) WetBond(tm); SB/F: Single Bond adhesive system + F; SB/EWB, s-SB/F and s-SB/EWB. In the s-SB/F and s-SB/EWB groups, the acid-etched enamel was contaminated with 0.01 mL of fresh human saliva for 20 s. Sealant cylinders were bonded to enamel surface with and without an intermediate adhesive system layer. The shear tests were performed using a universal testing machine (0.5 mm/min). Data were analyzed statistically by Kruskal-Wallis and Mann-Whitney tests (α=0.05). F presented higher mean SBS than EWB in all experimental conditions. The lowest SBS mean was obtained for EWB on contaminated enamel (p<0.05). In conclusion, an adhesive system layer should be used prior to sealant placement, in both dry and saliva-contaminated enamel. F had the best performance in all experimental conditions. EWB sealant showed very low results, but an adhesive layer underneath the sealant increased its SBS even after salivary contamination.

Parents' Attitude towards the Use of Fluorides and Fissure Sealants and its Effect on their Children's Oral Health.

Science.gov (United States)

Blumer, Sigalit; Ratson, Tal; Peretz, Benjamin; Dagon, Nurit

To characterize the attitudes of Israeli parents towards caries preventive measures. participating parents completed a 21-item questionnaire on their demographics, dental history, attitudes and satisfaction from fluorides and fissure sealants. One hundred parents (average age 41.62±4.9 years, 85 females) participated. Most of the parents (88% of the mothers and 84% of the fathers) had an academic education. Most of the parents (54%) had a favorable attitude towards the use of fluoridated gels, while only 37% of them had a positive opinion regarding fluoridated water. The satisfaction levels were very high regarding fissure sealants, fluoridated mouth rinses and fluoridated gels (78.1%, 73.6% and 72.5% respectively). The satisfaction from fluoridated water was split almost equally (50.8% were 'pleased' and 49.2% 'not pleased'). The main source for parental oral health knowledge was the dentist (83%). Parents' attitude towards caries preventive measures was significantly correlated to their gender, dental experience, level of education and the number of children in the family. positive attitude towards caries preventive measures was found among parents with higher awareness for preventive oral health measures and among bigger families. Mothers were more positive about fissure sealants than fathers. Mothers with up to 12 years of education tended to have a positive opinion regarding water fluoridation.

Development of a Novel Alginate-Based Pleural Sealant

Science.gov (United States)

2016-07-01

thoracotomy is performed on a anesthetized ventilated live rat (a), an incision is made to induce pleural air leak (b), and sealant material [ liquid ...AWARD NUMBER: W81XWH-15-1-0107 TITLE: Development of a Novel Alginate-Based Pleural Sealant PRINCIPAL INVESTIGATOR: Daniel J. Weiss MD PhD...SUBTITLE Development of a Novel Alginate-Based Pleural Sealant 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-15-1-0107 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR

Role of Fibrin Sealants in Liver Surgery

NARCIS (Netherlands)

de Boer, Marieke T.; Boonstra, Elizabeth A.; Lisman, Ton; Porte, Robert J.

2012-01-01

Background: Fibrin sealants are widely used in liver surgery. The aim of this article is to review the literature on evidence of hemostatic and biliostatic capacities of different fibrin sealants in liver surgery. Methods: In PubMed, a literature search was done with the search terms 'fibrin

Comparison of commercial fibrin sealants in facelift surgery: a prospective study

Directory of Open Access Journals (Sweden)

Botti G

2013-11-01

Full Text Available Giovanni Botti,1 Michele Pascali,2 Chiara Botti,1 Florian Bodog,3 Pietro Gentile,2 Valerio Cervelli2 1Villa Bella Clinic, Salò, 2Department of Plastic and Reconstructive Surgery, University of Rome Tor Vergata, Italy; 3University of Oradea, Oradea, Romania Background: The aim of this study was to compare the effects of two types of fibrin glue in patients undergoing facelift surgery. Methods: A prospective, controlled "right-left side" study was carried out in 20 patients. The two fibrin sealants used were Quixil® and Tissucol®. The two sealants were used at the same time, ie, one on one side of the face and the other on the contralateral side. Comparisons were made with regard to rates of hematoma and seroma, degree of induration, edema, ecchymosis, pain levels, and patient satisfaction. Results: The results were almost equivalent. The only exception was a significant (40 mL hematoma in a patient treated with Quixil. Bleeding was most likely due to a sudden rise in blood pressure during the immediate postoperative period. However, it must be emphasized that, while Tissucol actually seals the undermined area, thus virtually eliminating the dead space, Quixil acts differently, in that its effectiveness in preventing hematoma is linked mainly to its hemostatic effect. Conclusion: The two fibrin sealants used were nearly identical with regard to patient safety and quality of the result. Nevertheless, it is noted that, while Tissucol has both hemostatic and "gluing" effects, Quixil is mainly effective in securing hemostasis. Keywords: facelift surgery, rhytidectomy, fibrin sealants, hematoma

Leak tight sealants and joint details for concrete structure in RAPP

International Nuclear Information System (INIS)

Singha Roy, P.K.; Baste, M.S.

1975-01-01

Leak tightness may pertain to either air or water and in extreme cases each will require separate consideration based on general basic requirements. Leak-tight sealants against air pressure are required in the construction joints and around penetrations in the concrete containment structures. The containment structures should be able to withstand the maximum anticipated design pressure during the incident of a MCA with only minimal leakage (0.1% of bldg. volume per day in RAPP) which is mostly through these joints. Apart from proper joint design and preparation the sealant itself must have superb adhesion to the concrete surface and integrify throughout its service life to prevent any rupture or micro-cracks at any section of the joint. Leak tightness pertains to water tightness as well. A critical water-tight joint at the bottom dome of the prestressed concrete dousing tank at its junction with the 36 inches dia dousing water pipes constructed in RAPP-2, which should be able to withstand the water pressure, continuous submergence in the water of the tank and the longitudinal and lateral movement of the water pipes during opening and closure of the dousing valves, has been made and hydrostatically tested when not even the slight sweating was found. The construction and materials of the above joints and the sealant along with the properties and performance observed during testing/use are described. As the sealant used is an imported poly-sulphide caulking compound suggestions have also been made, which may be kept in mind while developing an Indian substitute. (author)

Plasma membrane disruption: repair, prevention, adaptation

Science.gov (United States)

McNeil, Paul L.; Steinhardt, Richard A.

2003-01-01

Many metazoan cells inhabit mechanically stressful environments and, consequently, their plasma membranes are frequently disrupted. Survival requires that the cell rapidly repair or reseal the disruption. Rapid resealing is an active and complex structural modification that employs endomembrane as its primary building block, and cytoskeletal and membrane fusion proteins as its catalysts. Endomembrane is delivered to the damaged plasma membrane through exocytosis, a ubiquitous Ca2+-triggered response to disruption. Tissue and cell level architecture prevent disruptions from occurring, either by shielding cells from damaging levels of force, or, when this is not possible, by promoting safe force transmission through the plasma membrane via protein-based cables and linkages. Prevention of disruption also can be a dynamic cell or tissue level adaptation triggered when a damaging level of mechanical stress is imposed. Disease results from failure of either the preventive or resealing mechanisms.

ART restorations and sealants placed in Chinese school children--results after three years.

Science.gov (United States)

Holmgren, C J; Lo, E C; Hu, D; Wan, H

2000-08-01

These were to assess whether ART restorations and sealants could be provided to children in a school environment in China, to assess patient acceptability of the ART approach, and to evaluate on a longitudinal basis the treatments performed. This study was conducted in Deyang, Sichuan Province, in western China. A total of 294 ART restorations were placed in 197 children and 191 fissure sealants were placed in 140 children by five middle-level dentists in four secondary schools. Standard instruments and procedures for ART were used. The restorative material used was a high-strength glass-ionomer (Ketac-Molar, ESPE). The treatments were evaluated annually after placement by the same examiner who had not been involved in the placement of the restorations nor sealants using explorers and mouth-mirrors. At the 3-year examination an independent external examiner evaluated the restorations using USPHS criteria. Most of the children did not report discomfort during treatment and 92% were willing to receive ART restorations again. The cumulative 1-year and 3-year survival rates of small Class I restorations were 99% and 92% respectively. The corresponding figures for large Class I restorations were 90% and 77%. After 3 years, 72% of the sealants were either partially or completely retained. Only 2% of the sealed teeth developed fissure caries and these involved teeth where the sealants had been lost. Similar success rates were found using USPHS criteria. The ART approach for preventing and treating tooth decay in Chinese school children was shown to be appropriate, effective and acceptable. The 3-year survival rates of the restorations were high but were related to the size and type of the restoration.

Two-year survival of glass ionomer sealants placed as part of ...

African Journals Online (AJOL)

, ... Results: The two-year cumulative survival of the sealants was 10.9%, and the survival of the sealants was not significantly affected by the GIC material brand and the toothisolation method used. However, slightly more sealants survived ...

Initial experience with a synthetic sealant PleuraSeal™ after pulmonary resections: a prospective study with retrospective case matched controls

Directory of Open Access Journals (Sweden)

Hennings Ellen

2010-06-01

Full Text Available Abstract The objective of this study was to evaluate postoperative outcome and efficacy of a hydrogel tissue sealant for prevention of alveolar leakage after open lung resections. 20 consecutive patients were enrolled in the PleuraSeal™ sealant group (PSG and case matched with 20 retrospective controls (CG with standard treatment. Assessment of postoperative air leakage was performed until chest tube removal. Patients were followed until 30 days after discharge. At end of surgery, 100% in the PSG and 0% in the CG were air leak free (p The study demonstrated a superior efficacy of PleuraSeal™ sealant compared with standard surgical treatment for sustained sealing of postoperative air leakage and causes shorter air leak chest tube duration.

Use of fibrin sealants in cardiovascular surgery: a systematic review.

Science.gov (United States)

Rousou, John A

2013-05-01

Fibrin sealants are used for hemostasis and tissue adherence. This systematic review summarizes published clinical data for fibrin sealant use in cardiovascular surgery. A literature search for the following terms was conducted using PubMed and EMBASE: (TISSEEL or Tissucol or Beriplast P or Evicel or Quixil or Crosseal or Reliseal or Fibringluraas or Bolheal or Tachosil or Vivostat or Vitagel or Artiss or "fibrin glue" or "fibrin sealant" or "fibrin tissue adhesive") and (cardiac or cardiovascular or vascular or heart or coronary or surgery). Case reports and series were excluded; although reports of controlled trials were preferred, uncontrolled trial data were also considered. Clinical trials and chart review analyses of fibrin sealants were identified and summarized. Although clinical trial data were available for other agents, the majority of published studies examined TISSEEL. Overall, TISSEEL and other fibrin sealants showed improvements over standard of care or control groups for a variety of predefined endpoints. Safety findings are also summarized. Data from these studies showed that fibrin sealants were well tolerated and provided effective hemostasis in a range of cardiac and aortic surgeries. © 2013 Wiley Periodicals, Inc.

Toxicity of coal-tar and asphalt sealants to eastern newts, Notophthalmus viridescens

Energy Technology Data Exchange (ETDEWEB)

Bommarito, T.; Sparling, D.W.; Halbrook, R.S. [South Illinois University, Carbondale, IL (United States). Cooperative Wildlife Research Laboratory

2010-09-15

Between 1970 and 2000 the concentration of total polycyclic aromatic hydrocarbons (TPAH) in several lakes across the country increased whereas those of other persistent organic pollutants (POPs) tended to remain stable or declined. Urbanized watersheds experienced greater rises in TPAH concentration compared to non-urban lakes. Sources for urban PAHs include industrial wastes, vehicular exhausts and oil leaks and sealants from pavement surfaces. Both coal-tar and asphalt sealants are used to protect surfaces but runoff from surfaces coated with coal-tar can have mean concentrations of 3500 mg TPAHs kg{sup -1}, much higher than runoff from asphalt-sealed or cement surfaces. Unaltered parent compounds of PAHs can have many lethal and sublethal toxic effects, but oxidation and UV radiation can alter the toxicity of these compounds, sometimes creating degradates that are many times more toxic than parent compounds. The purposes of this study were to determine if coal-tar sealants can be toxic to adult eastern newts (Notophthalmus viridescens) and to compare the toxicity of coal-tar sealant to that of asphalt sealant. Newts were exposed to sediments containing dried sealants ranging from 0 mg kg{sup -1} to 1500 mg kg{sup -1} under simultaneous exposure to UV radiation and visible light to determine concentration/response relationships. No significant mortality occurred with any treatment. Significant effects due to sealants included decreased righting ability and diminished liver enzyme activities. Coal-tar sealant was more effective in inducing these changes than was asphalt sealant.

Effect of chain extender on properties of silicone rubber sealant

Science.gov (United States)

Liu, Jiesheng; Wu, Shaopeng; Mi, Yixuan; Zhu, Guojun; Zheng, Shaoping

2010-03-01

The room-temperature vulcanizing silicone rubber sealant was prepared with chain extender. The effect of chain extender on the properties of silicone rubber sealant was discussed. The composite samples with chain extender were investigated from the aspects of tack-free time, cross-linkage density, hardness (penetration number) and adhesive strength with the concrete slab. It was found that the adding of the chain extender effectively makes the molecular chain length increase and causes the mechanical properties improvement. In addition, the increase in the amount of the chain extender reduces the cross-linkage density and hardness of silicone rubber sealant, which is accompanied with a decrease in the tack-free time. Adhesive strength is one of the most important requirements for sealant. The effect of chain extender on the adhesive strength was also investigated in this study. It was found that the increase in the amount of the chain extender makes the adhesive strength between the sealant and the concrete slab decrease.

A 1-year clinical evaluation of fissure sealants on permanent first molars

Directory of Open Access Journals (Sweden)

Nupur Ninawe

2012-01-01

Full Text Available Objective : To evaluate and compare the retention, marginal discoloration, surface texture and anatomical form of pit and fissure sealants. Materials and Methods : Thirty children between the ages of 6 and 10 years, who were attending the school health program regularly, had participated in the study. A split-mouth design was used in which the two fissure sealants (Helioseal-F and Glass ionomer Fuji VII were randomly placed in 60 matched contralateral pairs of permanent molar teeth. Sealants were rated by a single trained and calibrated examiner using mouth mirrors and probes following the US Public Health Service criteria. The sealants were evaluated at 3 months, 6 months and 1 year intervals. Results : The data obtained for retention, marginal discoloration, surface texture and anatomical form of pit and fissure sealants were tabulated and compared statistically using the Chi-square test of significance. Conclusion : The Helioseal-F sealant was better than the Glass ionomer Fuji VII sealant with respect to retention, anatomical form and surface texture. Both the materials showed similar results with respect to marginal discoloration.

Tensile strength of biological fibrin sealants: a comparative study.

Science.gov (United States)

Lacaze, Laurence; Le Dem, Nicolas; Bubenheim, Michael; Tsilividis, Basile; Mezghani, Julien; Schwartz, Lilian; Francois, Arnaud; Ertaud, Jean Yves; Bagot d'Arc, Maurice; Scotté, Michel

2012-08-01

Fibrin sealants are commonly used in liver surgery, although their effectiveness in routine clinical practice remains controversial. Individual sealant characteristics are based on hemostatic effects and adhesion properties that can be experimentally measured using the 'rat skin test' or the 'pig skin test'. This study used a more relevant and realistic experimental canine model to compare the differences in the adhesive properties of four fibrin sealants in hepatectomy: Tisseel/Tissucol, Tachosil, Quixil, and Beriplast. A partial hepatectomy was performed in beagle dogs under general anesthesia to obtain liver cross-sections. Fibrin sealants were allocated to dog livers using a Youden square design. The tensile strength measurement was performed using a traction system to measure the rupture stress point of a small wooden cylinder bonded to the liver cross-section. Significantly greater adhesion properties were observed with Tisseel/Tissucol compared with Quixil or Beriplast (P = 0.002 and 0.001, respectively). Similarly, Tachosil demonstrated significantly greater adhesive properties compared with Beriplast (P = 0.009) or Quixil (P = 0.014). No significant differences were observed between Tisseel/Tissucol and Tachosil or between Beriplast and Quixil. The results of this comparative study demonstrate that different fibrin sealants exhibit different adhesive properties. Tisseel/Tissucol and Tachosil provided greatest adhesion to liver cross-section in our canine model of hepatectomy. These results may enable the optimal choice of fibrin sealants for this procedure in clinical practice. Copyright © 2012 Elsevier Inc. All rights reserved.

Coal-tar based pavement sealant toxicity to freshwater macroinvertebrates

International Nuclear Information System (INIS)

Bryer, Pamela J.; Scoggins, Mateo; McClintock, Nancy L.

2010-01-01

Non-point-source pollution is a major source of ecological impairment in urban stream systems. Recent work suggests that coal-tar pavement sealants, used extensively to protect parking areas, may be contributing a large portion of the polycyclic aromatic hydrocarbon (PAH) loading seen in urban stream sediments. The hypothesis that dried coal-tar pavement sealant flake could alter the macroinvertebrate communities native to streams in Austin, TX was tested using a controlled outdoor laboratory type approach. The treatment groups were: control, low, medium, and high with total PAH concentrations (TPAH = sum of 16 EPA priority pollutant PAHs) of 0.1, 7.5, 18.4, and 300 mg/kg respectively. The low, medium, and high treatments were created via the addition of dried coal-tar pavement sealant to a sterile soil. At the start of the 24-day exposure, sediment from a minimally impacted local reference site containing a community of live sediment-dwelling benthic macroinvertebrates was added to each replicate. An exposure-dependent response was found for several stream health measures and for several individual taxa. There were community differences in abundance (P = 0.0004) and richness (P < 0.0001) between treatments in addition to specific taxa responses, displaying a clear negative relationship with the amount of coal-tar sealant flake. These results support the hypothesis that coal-tar pavement sealants contain bioavailable PAHs that may harm aquatic environments. - Coal-tar pavement sealants degrade stream invertebrate communities.

Comparison of microleakage between flowable nanocomposite, flowable Composite and Conventional sealant in fissure sealant therapy of the permanent teeth: an in- vitro study

Directory of Open Access Journals (Sweden)

Sara Maleki Kambakhsh

2016-11-01

Full Text Available Background and Aim: Novel dental materials including nanocomposites have been introduced in recent years. It is claimed that they have superior properties such as high esthetic., low wear, increased filler content resulting in better mechanical properties, and releasing ions i.e. fluoride and amorphous calcium phosphate that are important for enamel remineralization. Considering these features, if they have retention and microleakage rates comparable with conventional sealants, these materials can be appropriate alternatives to conventional resin sealants in future. The current study aimed at comparing . microleakage of a flowable nanocomposite, a flowable composite , and a conventional sealant in fissure sealant therapy of the permanent teeth. Materials and Methods: First of all ,42 extracted sound human maxillary first premolars were collected and were randomly divided into 3 equal groups. Then the teeth were embedded in self-cure acrylic resin. Occlusal fissures of the samples were cleaned using explorer, enameloplasty with ¼ round diamond bur and water/air spray was done. The prepared surfaces were etched using 36% phosphoric acid gel for 15s, rinsed and dried. Bonding agent was placed in the pits and fissures, cured for 10s after thinning with air. In the first, second , and the third group conventional sealant, flowable composite , and flowable nanocomposite were placed, respectively; and light cured for 40s. The samples were thermocycled (1000 cycles between 5-55ºC and then immersed in 2% basic Fuchsine solution for 24hs. They were then cut bucculingually and microleakage evaluation was done using stereomicroscope. The obtained data was analyzed using Kruskal wallis tests. Results: There was no significant difference in microleakage rate of the study groups. (P>0.05. Conclusion: Considering the condition of the study, it can be concluded that flowable composite and flowable nanocomposite can be used as suitable alternatives to

Synthetic phenolic antioxidants, including butylated hydroxytoluene (BHT), in resin-based dental sealants

Energy Technology Data Exchange (ETDEWEB)

Wang, Wei; Kannan, Pranav; Xue, Jingchuan [Wadsworth Center, New York State Department of Health, and Department of Environmental Health Sciences, School of Public Health, State University of New York at Albany, Empire State Plaza, P.O. Box 509, Albany, NY 12201-0509 (United States); Kannan, Kurunthachalam, E-mail: Kurunthachalam.kannan@health.ny.gov [Wadsworth Center, New York State Department of Health, and Department of Environmental Health Sciences, School of Public Health, State University of New York at Albany, Empire State Plaza, P.O. Box 509, Albany, NY 12201-0509 (United States); Biochemistry Department, Faculty of Science, Experimental Biochemistry Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah (Saudi Arabia)

2016-11-15

Resin-based dental sealants (also referred to as pit-and-fissure sealants) have been studied for their contribution to bisphenol A (BPA) exposure in children. Nevertheless, little attention has been paid to the occurrence of other potentially toxic chemicals in dental sealants. In this study, the occurrence of six synthetic phenolic antioxidants (SPAs), including 2,6-di-tert-butyl-4-hydroxytoluene (BHT), 2,6-di-tert-butyl-4-(hydroxyethyl)phenol (BHT-OH), 3,5-di-tert-butyl-4-hydroxy-benzaldehyde (BHT-CHO), 2,6-di-tert-butylcyclohexa-2,5-diene-1,4-dione (BHT-Q), 3,5-di-tert-butyl-4-hydroxybenzoic acid (BHT-COOH) and 2-tert-butyl-4-methoxyphenol (BHA), was examined in 63 dental sealant products purchased from the U.S. market. BHT was found in all dental sealants at median and maximum concentrations of 56.8 and 1020 µg/g, respectively. The metabolites of BHT and BHA were detected in 39–67% of samples, at concentration ranges of sealants to inhibit oxidative reactions, remove free radicals, and inhibit potential polymerization, which would eventually prolong the shelf-life of the products. The estimated daily intake (EDI) of BHT, following sealant placement, based on a worst-case scenario (application on eight teeth at 8 mg each tooth), was 930 and 6510 ng/kg bw/d for adults and children, respectively. The EDI of BHT from dental sealants was several orders of magnitude lower than the current acceptable daily intake (ADI) proposed by the European Food Safety Authority (EFSA). - Highlights: • Synthetic phenolic antioxidants (SPAs) were detected in dental sealants. • 2,6-di-tert-butyl-4-hydroxytoluene (BHT) concentration of up to 1020 µg/g was found. • Estimated daily intake of BHT after sealant placement was up to 9.52 µg/kg bw/d. • Daily intake of BHT through dental sealant application was below the acceptable daily intake.

Synthetic phenolic antioxidants, including butylated hydroxytoluene (BHT), in resin-based dental sealants

International Nuclear Information System (INIS)

Wang, Wei; Kannan, Pranav; Xue, Jingchuan; Kannan, Kurunthachalam

2016-01-01

Resin-based dental sealants (also referred to as pit-and-fissure sealants) have been studied for their contribution to bisphenol A (BPA) exposure in children. Nevertheless, little attention has been paid to the occurrence of other potentially toxic chemicals in dental sealants. In this study, the occurrence of six synthetic phenolic antioxidants (SPAs), including 2,6-di-tert-butyl-4-hydroxytoluene (BHT), 2,6-di-tert-butyl-4-(hydroxyethyl)phenol (BHT-OH), 3,5-di-tert-butyl-4-hydroxy-benzaldehyde (BHT-CHO), 2,6-di-tert-butylcyclohexa-2,5-diene-1,4-dione (BHT-Q), 3,5-di-tert-butyl-4-hydroxybenzoic acid (BHT-COOH) and 2-tert-butyl-4-methoxyphenol (BHA), was examined in 63 dental sealant products purchased from the U.S. market. BHT was found in all dental sealants at median and maximum concentrations of 56.8 and 1020 µg/g, respectively. The metabolites of BHT and BHA were detected in 39–67% of samples, at concentration ranges of sealants to inhibit oxidative reactions, remove free radicals, and inhibit potential polymerization, which would eventually prolong the shelf-life of the products. The estimated daily intake (EDI) of BHT, following sealant placement, based on a worst-case scenario (application on eight teeth at 8 mg each tooth), was 930 and 6510 ng/kg bw/d for adults and children, respectively. The EDI of BHT from dental sealants was several orders of magnitude lower than the current acceptable daily intake (ADI) proposed by the European Food Safety Authority (EFSA). - Highlights: • Synthetic phenolic antioxidants (SPAs) were detected in dental sealants. • 2,6-di-tert-butyl-4-hydroxytoluene (BHT) concentration of up to 1020 µg/g was found. • Estimated daily intake of BHT after sealant placement was up to 9.52 µg/kg bw/d. • Daily intake of BHT through dental sealant application was below the acceptable daily intake.

A prospective randomized trial comparing homologous and autologous fibrin sealants for the control of alveolar air leak.

Science.gov (United States)

Kılıç, Burcu; Erşen, Ezel; Demirkaya, Ahmet; Kara, H Volkan; Alizade, Nurlan; İşcan, Mehlika; Kaynak, Kamil; Turna, Akif

2017-09-01

Postoperative air leak is a common complication seen after pulmonary resection. It is a significant reason of morbidity and also leads to greater hospital cost owing to prolonged length of stay. The purpose of this study is to compare homologous sealant with autologous one to prevent air leak following pulmonary resection. A total of 57 patients aged between 20 and 79 (mean age: 54.36) who underwent pulmonary resection other than pneumonectomy (lobar or sublobar resections) were analyzed. There were 47 males (83%) and 10 females (17%). Patients who intraoperatively had air leaks were randomized to receive homologous (Tisseel; n=28) or autologous (Vivostat; n=29) fibrin sealant. Differences among groups in terms of air leak, prolonged air leak, hospital stay, amount of air leak were analyzed. Indications for surgery were primary lung cancer in 42 patients (71.9%), secondary malignancy in 5 patients (8.8%), and benign disease in 10 patients (17.5%). Lobectomy was performed in 40 patients (70.2%), whereas 17 patients (29.8%) had wedge resection. Thirteen (46.4%) patients developed complications in patients receiving homologous sealant while 11 (38.0%) patients had complication in autologous sealant group (P=0.711). Median duration of air leak was 3 days in two groups. Time to intercostal drain removal was 3.39 and 3.38 days in homologous and autologous sealant group respectively (P=0.978). Mean hospital stay was 5.5 days in patients receiving homologous sealant whereas it was 5.0 days in patients who had autologous agent (P=0.140). There were no significant differences between groups in terms of measured maximum air leak (P=0.823) and mean air leak (P=0.186). There was no significant difference in the incidence of complications between two groups (P=0.711). Autologous and heterologous fibrin sealants are safe and acts similarly in terms of air leak and hospital stay in patients who had resectional surgery.

The differences of saliva pH before and after application of Bis-GMA resin based-pit and fissure sealant

Directory of Open Access Journals (Sweden)

Ayub Irmadani Anwar

2016-06-01

Full Text Available Pit and fissure sealant applications is one way to prevent caries. One of the effective ingredient as a pit and fissure sealant is a Bis-GMA resin. One of the active components  of  Bis-GMA  resin  is  sodium  fluoride,  which is capable  of releasing fluoride ions to the tooth surface and able to improve the repair and remineralization process through the replacement  of  calcium and phosphate ions found in saliva to increase the pH of saliva. This study was to determine the effect of pit and fissure sealant applications made from Bis-GMA resin to pH of saliva in children aged 6-12 years. The study design is pre and post test with control group design. Saliva samples were derived from 15 pediatric patients has met the criteria. The pH of saliva were taken before and after the application of pit and fissure sealant made from Bis-GMA and measured with pH meter. This study used a non-parametric test, the Wilcoxon Signed Rank test. The results of this study are also supported by the results of statistical tests showed p-: 0.005 (p<0.05 value, which means that there are significant differences in pH of saliva before and after the application of pit and fissure sealant made from Bis-GMA resin.

Prevalence of Dental Caries and Fissure Sealants in a Portuguese Sample of Adolescents

Science.gov (United States)

Veiga, Nélio J.; Pereira, Carlos M.; Ferreira, Paula C.; Correia, Ilidio J.

2015-01-01

Introduction The aims of this study were to assess the prevalence of dental caries and the DMFT index, as well as the distribution pattern of pit and fissure sealants on permanent teeth in a Portuguese sample of adolescents, and to assess whether the existing usage of sealants and socio-demographic factors are correlated to caries prevalence on the examined sample. Materials and Methods A cross-sectional study was designed with a sample of 447 adolescents aged 12 to 18 years old, attending a public school in Sátão, Portugal. A self-administered questionnaire with questions about oral health behaviours and socio-economic status was answered by adolescents in the classroom. Clinical examination of oral health status and assessment of fissure sealants were accomplished by only one trained member of the research team. Results We obtained a DMFT index of 3.32 (2.92), which indicates a moderate level of prevalence of dental caries. When considering a DMFT = 0, we found significant statistical differences between the parents´ level of education (≤ 4th grade = 26.3 vs 5th–12th grade = 18.8 vs Portuguese adolescents. The establishment of a more targeted preventive program with better and more effective oral health education is essential, having into account socio-demographic aspects. PMID:25803849

Reimbursement rates and policies for primary molar pit-and-fissure sealants across state Medicaid programs.

Science.gov (United States)

Chi, Donald L; Singh, Jennifer

2013-11-01

Little is known about Medicaid policies regarding reimbursement for placement of sealants on primary molars. The authors identified Medicaid programs that reimbursed dentists for placing primary molar sealants and hypothesized that these programs had higher reimbursement rates than did state programs that did not reimburse for primary molar sealants. The authors obtained Medicaid reimbursement data from online fee schedules and determined whether each state Medicaid program reimbursed for primary molar sealants (no or yes). The outcome measure was the reimbursement rate for permanent tooth sealants (calculated in 2012 U.S. dollars). The authors compared mean reimbursement rates by using the t test (α = .05). Seventeen Medicaid programs reimbursed dentists for placing primary molar sealants (34 percent), and the mean reimbursement rate was $27.57 (range, $16.00 [Maine] to $49.68 [Alaska]). All 50 programs reimbursed dentists for placement of sealants on permanent teeth. The mean reimbursement for permanent tooth sealants was significantly higher in programs that reimbursed for primary molar sealants than in programs that did not ($28.51 and $23.67, respectively; P = .03). Most state Medicaid programs do not reimburse dentists for placing sealants on primary molars, but programs that do so have significantly higher reimbursement rates. Medicaid reimbursement rates are related to dentists' participation in Medicaid and children's dental care use. Reimbursement for placement of sealants on primary molars is a proxy for Medicaid program generosity.

The effect of surface sealants with different filler content on microleakage of Class V resin composite restorations.

Science.gov (United States)

Hepdeniz, Ozge Kam; Temel, Ugur Burak; Ugurlu, Muhittin; Koskan, Ozgur

2016-01-01

Microleakage is still one of the most cited reasons for failure of resin composite restorations. Alternative methods to prevent microleakage have been investigated increasingly. The aim of this study is to evaluate the microleakage in Class V resin composite restorations with or without application of surface sealants with different filler content. Ninety-six cavities were prepared on the buccal and lingual surfaces with the coronal margins located in enamel and the cervical margins located in dentin. The cavities restored with an adhesive system (Clearfil SE Bond, Kuraray, Tokyo, Japan) and resin composite (Clearfil Majesty ES-2, Kuraray, Tokyo, Japan). Teeth were stored in distilled water for 24 h and separated into four groups according to the surface sealants (Control, Fortify, Fortify Plus, and G-Coat Plus). The teeth were thermocycled (500 cycles, 5-55° C), immersed in basic fuchsine, sectioned, and analyzed for dye penetration using stereomicroscope. The data were submitted to statistical analysis by Kruskal-Wallis and Bonferroni-Dunn test. The results of the study indicated that there was minimum leakage at the enamel margins of all groups. Bonferroni-Dunn tests revealed that Fortify and GC-Coat groups showed significantly less leakage than the Control group and the Fortify Plus group at dentin margins in lingual surfaces (P < 0.05). The all surface sealants used in this study eliminated microleakage at enamel margins. Moreover, unfilled or nanofilled surface sealants were the most effective in decreasing the degree of marginal microleakage at dentin margins. However, viscosity and penetrability of the sealants could be considered for sealing ability besides composition.

Engaging Stakeholders in Patient-Centered Outcomes Research Regarding School-Based Sealant Programs.

Science.gov (United States)

Chi, Donald L; Milgrom, Peter; Gillette, Jane

2018-02-01

Purpose: The purpose of this study was to use qualitative methods to describe the key lessons learned during the stakeholder engagement stage of planning a randomized clinical trial comparing outcomes of silver diamine fluoride (SDF) as an alternative to pit-and-fissure sealants in a school-based delivery system. Methods: Eighteen caregivers and community-based stakeholders with involvement in the school-based sealant program Sealants for Smiles from the state of Montana, were recruited for this qualitative study. United States (U.S.) Patient-Centered Outcomes Research Institute (PCORI) methodology standards were used to develop two semi-structured interview guides consisting of 6 questions. One interview guide was used for telephone interviews with caregivers and the second was used for a stakeholder focus group. Content analytic methods were used to analyze the data. Results: All participants believed that a study comparing SDF and sealants was clinically relevant. Non-caregiver stakeholders agreed with the proposed primary outcome of the study (caries prevention) whereas caregivers also emphasized the importance of child-centered outcomes such as minimizing dental anxiety associated with dental care. Stakeholders described potential concerns associated with SDF such as staining and perceptions of safety and discussed ways to address these concerns through community engagement, appropriate framing of the study, proper consent procedures, and ongoing safety monitoring during the trial. Finally, stakeholders suggested dissemination strategies such as direct communication of findings through professional organizations and encouraging insurance plans to incentivize SDF use by reimbursing dental providers. Conclusions: Involving key stakeholders in early planning is essential in developing patient-centered research questions, outcomes measures, study protocols, and dissemination plans for oral health research involving a school-based delivery system. Copyright © 2018

Coal-tar based pavement sealant toxicity to freshwater macroinvertebrates

Energy Technology Data Exchange (ETDEWEB)

Bryer, P.J.; Scoggins, M.; McClintock, N.L. [Lamar University, Beaumont, TX (United States). Dept. of Biology

2010-05-15

Non-point-source pollution is a major source of ecological impairment in urban stream systems. Recent work suggests that coal-tar pavement sealants, used extensively to protect parking areas, may be contributing a large portion of the polycyclic aromatic hydrocarbon (PAH) loading seen in urban stream sediments. The hypothesis that dried coal-tar pavement sealant flake could alter the macroinvertebrate communities native to streams in Austin, TX was tested using a controlled outdoor laboratory type approach. The treatment groups were: control, low, medium, and high with total PAH concentrations (TPAH = sum of 16 EPA priority pollutant PAHs) of 0.1, 7.5, 18.4, & 300 mg/kg respectively. The low, medium, and high treatments were created via the addition of dried coal-tar pavement sealant to a sterile soil. At the start of the 24-day exposure, sediment from a minimally impacted local reference site containing a community of live sediment-dwelling benthic macroinvertebrates was added to each replicate. An exposure-dependent response was found for several stream health measures and for several individual taxa. There were community differences in abundance (P = 0.0004) and richness (P < 0.0001) between treatments in addition to specific taxa responses, displaying a clear negative relationship with the amount of coal-tar sealant flake. These results support the hypothesis that coal-tar pavement sealants contain bioavailable PAHs that may harm aquatic environments.

Sealants fight back aginst bacteria.

Science.gov (United States)

Moran, Mike

2008-09-01

Mike Moran, business development manager, Industrial Construction, at Bostik, explains how a range of new sealants increase protection in hospital bathrooms, shower rooms and kitchen facilities against healthcare-acquired infections.

Clinical effectiveness and cost-effectiveness of fissure sealants in children and adolescents with a high caries risk

Directory of Open Access Journals (Sweden)

Neusser, Silke

2014-10-01

Full Text Available [english] In Germany, the application of resin-based pits and fissures sealants on the occlusal surfaces of permanent molars is part of individual prophylaxis for children and adolescents between six and 18 years. The individual prophylaxis is covered by the Statutory Health Insurance since 1993.The report addresses questions on medical effectiveness, cost-effectiveness, as well as ethical, social, and legal implications of pit and fissure sealants in preventing dental caries for children and adolescents at high caries risk. The results of the studies indicate a protective effect of pit and fissure sealants, particularly for children and adolescents at high caries risk. Additionally, the economic evaluation suggests a tendency for cost savings in this group. Nevertheless, a general expansion of the intervention cannot be recommended. All studies show a risk of bias in favour of pit and fissure sealing and a limited transferability to the German health care system. Studies included in the economic evaluation revealed methodological flaws. Both the economic models and primary studies do not provide reliable results.

Process for nondestructively testing with radioactive gas using a chill set sealant

International Nuclear Information System (INIS)

Gibbons, C.B.

1975-01-01

An article surface is nondestructively tested for substantially invisible surface voids by absorbing a radioactive gas thereon. The adsorbed radioactive gas is disproportionately retained on those surfaces presented by the substantially invisible surface voids as compared to the remaining surfaces of the article contacted by the radioactive gas. The radiation released by the radioactive gas remaining adsorbed is used to identify the substantially invisible voids. To immobilize the radioactive gas adjacent or within the surface voids, a sealant composition is provided which is capable of being chill set. The temperatures of the article surface to be tested and the sealant composition are then related so that the article surface is at a temperature below the chill set temperature of the sealant composition and the sealant composition is at a temperature above its chill set temperature. The article portion to be tested is then coated with sealant composition to form a chill set coating thereon of substantially uniform thickness. (U.S.)

Effect of a surface sealant on the color stability of composite resins after immersion in staining solution.

Science.gov (United States)

Pedroso, Lauana Borges; Barreto, Luma Franciélle Cabreira; Miotti, Leonardo Lamberti; Nicoloso, Gabriel Ferreira; Durand, Leticia Brandão

2016-01-01

This study evaluated the influence of surface sealants on the color stability of 2 different composite resins after immersion in coffee. Four groups were created (n = 10): microhybrid composite, microhybrid with surface sealant, nanofilled composite, and nanofilled composite with surface sealant. Half of the specimens of each group were immersed in distilled water and half were immersed in coffee for 48 hours. Color was measured before and after immersion. Groups with surface sealants presented less color variation when compared with the groups without surface sealants. The nanofilled resin specimens presented the greatest color variation within the groups without sealant. The surface sealant positively influenced the color stability of composite resin specimens immersed in coffee. When surface sealant was not applied, the microhybrid specimens had better color stability than the nanofilled.

The effect of bonding agents on the microleakage of sealant following contamination with saliva

Directory of Open Access Journals (Sweden)

Askarizadeh Nahid

2008-06-01

Full Text Available Aims : An issue of concern in dentistry is the inadequacy of adhesion and proper sealing following restoration of a tooth, which can lead to marginal leakage. The aim of this study was to evaluate the effect of a bonding agent on the microleakage of a sealant material following contamination with saliva. Materials and Methods : In this experimental research, 48 sound premolars were divided into two groups. The first group received sealant without bonding and the other group was given sealant with bonding. After prophylaxis, the occlusal surfaces were etched with 37% phosphoric acid gel and the teeth were then placed in fresh human saliva for l0 s. Following this, in the first group fissure sealant (Kerr was applied directly and cured; for the second group sealant was placed and cured after bonding (Single Bond; 3M. All samples were thermocycled (500 cycles; between 5°C and 55°C; dwell time of 30 s. Silver nitrate was used as the leakage tracer. The teeth were sectioned. Microleakage evaluation was made by stereomicroscope at 40x magnification and the results were evaluated with the Mann-Whitney U test. Results : In the group that received sealant without bonding extensive microleakage was seen; placement of sealant with bonding significantly reduced microleakage. Conclusion : In the presence of contamination with saliva, use of bonding under the fissure sealant can reduce microleakage

Dental sealant knowledge, opinion, values and practice of Spanish dentists

Directory of Open Access Journals (Sweden)

San Martin Laura

2013-02-01

Full Text Available Abstract Background Multiple guidelines and systematic reviews recommend sealant use to reduce caries risk. Yet, multiple reports also indicate that sealants are significantly underutilized. This study examined the knowledge, opinions, values, and practice (KOVP of dentists concerning sealant use in the southwest region of Andalusia, Spain. This is a prelude to the generation of a regional plan for improving children’s oral health in Andalusia. Methods The survey’s target population was dentists working in western Andalusia, equally distributed in the provinces of Seville, Cadiz, and Huelva (N=2,047. A convenience sample of meeting participants and meeting participant email lists (N=400 were solicited from the annual course on Community and Pediatric Dentistry. This course is required for all public health sector dentists, and is open to all private sector dentists. Information on the dentist’s KOVP of sealants was collected using four-part questionnaire with 31, 5-point Likert-scaled questions. Results The survey population demographics included 190 men (48% and 206 women (52% with an average clinical experience of 10.6 (± 8.4 years and 9.3 (± 7.5 years, respectively. A significant sex difference was observed in the distribution of place of work (urban/suburb (p=0.001, but no sex differences between working sector (public/private. The mean ± SD values for each of the four KOVP sections for pit and fissure sealants were: knowledge = 3.57 ± 0.47; opinion = 2.48 ± 0.47; value = 2.74 ± 0.52; and practice = 3.48 ± 0.50. No sex differences were found in KOVP (all p >0.4. Independent of sex: knowledge statistically differed by years of experience and place of work; opinion statistically differed by years of experience and sector; and practice statistically differed by years of experience and sector. Less experienced dentists tended to have slightly higher scores (~0.25 on a Likert 1–5 scale. Statistically significant correlations were

Marginal leakage of two newer glass-ionomer-based sealant materials assessed using micro-CT.

NARCIS (Netherlands)

Chen, X.; Cuijpers, V.M.J.I.; Fan, M.; Frencken, J.E.F.M.

2010-01-01

OBJECTIVES: To test newer glass-ionomer-based materials as sealant materials. One glass-ionomer sealant was light-cured to obtain an early setting reaction. The null-hypothesis tested was: there is no difference in marginal leakage of sealants produced with high-viscosity glass-ionomer, with and

Traditional preventive treatment options

DEFF Research Database (Denmark)

Longbottom, C; Ekstrand, K; Zero, D

2009-01-01

Preventive treatment options can be divided into primary, secondary and tertiary prevention techniques, which can involve patient- or professionally applied methods. These include: oral hygiene (instruction), pit and fissure sealants ('temporary' or 'permanent'), fluoride applications (patient...... options....

Evaluation of microtensile bond strength of different fissure sealants to bovine enamel.

Science.gov (United States)

Sen Tunc, E; Bayrak, S; Tuloglu, N; Ertas, E

2012-03-01

The aim of this study was to evaluate the microtensile bond strength (μTBS) of a new fissure sealant and compare it with conventional sealants which are applied to enamel alone, and also with self-etch and etch-and-rinse adhesives. Enamel specimens were prepared and randomly distributed into three groups according to fissure sealant (Aegis, Helioseal F, Helioseal Clear). Each group was then subdivided according to adhesive system (Clearfil S3, Single Bond, no adhesive). A universal testing machine was used to measure μTBS, and data were analysed using one-way ANOVA and Tukey's tests. μTBS values for all Aegis subgroups were significantly lower than for comparable Helioseal F and Helioseal Clear subgroups (p 0.05). In the Helioseal Clear group, μTBS values for Single Bond were significantly higher than for Clearfil S3 (p adhesive subgroups in the Aegis or Helioseal F groups (p > 0.05). Sealant μTBS values may be affected by material content. The addition of an adhesive may improve μTBS values of sealant to enamel. © 2012 Australian Dental Association.

Effectiveness of two new types of sealants: retention after 2 years

NARCIS (Netherlands)

Chen, X.; Du, M.; Fan, M.; Mulder, J.; Huysmans, M.C.; Frencken, J.E.

2012-01-01

The hypotheses tested were: survival rate of fully and partially retained glass-carbomer sealants is higher than those of high-viscosity glass-ionomer, with and without energy supplied, and that of resin composite; survival rate of fully and partially retained sealants of high-viscosity

Applying psychological theories to evidence-based clinical practice: identifying factors predictive of placing preventive fissure sealants.

Science.gov (United States)

Bonetti, Debbie; Johnston, Marie; Clarkson, Jan E; Grimshaw, Jeremy; Pitts, Nigel B; Eccles, Martin; Steen, Nick; Thomas, Ruth; Maclennan, Graeme; Glidewell, Liz; Walker, Anne

2010-04-08

Psychological models are used to understand and predict behaviour in a wide range of settings, but have not been consistently applied to health professional behaviours, and the contribution of differing theories is not clear. This study explored the usefulness of a range of models to predict an evidence-based behaviour -- the placing of fissure sealants. Measures were collected by postal questionnaire from a random sample of general dental practitioners (GDPs) in Scotland. Outcomes were behavioural simulation (scenario decision-making), and behavioural intention. Predictor variables were from the Theory of Planned Behaviour (TPB), Social Cognitive Theory (SCT), Common Sense Self-regulation Model (CS-SRM), Operant Learning Theory (OLT), Implementation Intention (II), Stage Model, and knowledge (a non-theoretical construct). Multiple regression analysis was used to examine the predictive value of each theoretical model individually. Significant constructs from all theories were then entered into a 'cross theory' stepwise regression analysis to investigate their combined predictive value. Behavioural simulation - theory level variance explained was: TPB 31%; SCT 29%; II 7%; OLT 30%. Neither CS-SRM nor stage explained significant variance. In the cross theory analysis, habit (OLT), timeline acute (CS-SRM), and outcome expectancy (SCT) entered the equation, together explaining 38% of the variance. Behavioural intention - theory level variance explained was: TPB 30%; SCT 24%; OLT 58%, CS-SRM 27%. GDPs in the action stage had significantly higher intention to place fissure sealants. In the cross theory analysis, habit (OLT) and attitude (TPB) entered the equation, together explaining 68% of the variance in intention. The study provides evidence that psychological models can be useful in understanding and predicting clinical behaviour. Taking a theory-based approach enables the creation of a replicable methodology for identifying factors that may predict clinical behaviour

Self-Healable and Reprocessable Polysulfide Sealants Prepared from Liquid Polysulfide Oligomer and Epoxy Resin.

Science.gov (United States)

Gao, Wentong; Bie, Mengyao; Liu, Fu; Chang, Pengshan; Quan, Yiwu

2017-05-10

Polysulfide sealants have been commercially applied in many industrial fields. In this article, we study the self-healing property of the epoxy resin-cured polysulfide sealants for the first time. The obtained sealants showed a flexible range of ultimate elongation of 157-478% and a tensile strength of 1.02-0.75 MPa corresponding to different polysulfide oligomers. By taking advantage of the dynamic reversible exchange of disulfide bonds, polysulfide sealants exhibited good self-healing ability under a moderate thermal stimulus. A higher molecular weight and a lower degree of cross-linking of polysulfide oligomer were helpful in improving the ultimate elongation and healing efficiency of the polysulfide sealants. After subjecting to a temperature of 75 °C for 60 min, both the tensile strength and ultimate elongation of a fully cut sample, LP55-F, were restored to 91% of the original values, without affecting the sealing property. Furthermore, the sample exhibited excellent reshaping and reprocessing abilities. These outcomes offer a paradigm toward sustainable industrial applications of the polysulfide-based sealants.

Coal-tar based pavement sealant toxicity to freshwater macroinvertebrates.

Science.gov (United States)

Bryer, Pamela J; Scoggins, Mateo; McClintock, Nancy L

2010-05-01

Non-point-source pollution is a major source of ecological impairment in urban stream systems. Recent work suggests that coal-tar pavement sealants, used extensively to protect parking areas, may be contributing a large portion of the polycyclic aromatic hydrocarbon (PAH) loading seen in urban stream sediments. The hypothesis that dried coal-tar pavement sealant flake could alter the macroinvertebrate communities native to streams in Austin, TX was tested using a controlled outdoor laboratory type approach. The treatment groups were: control, low, medium, and high with total PAH concentrations (TPAH = sum of 16 EPA priority pollutant PAHs) of 0.1, 7.5, 18.4, & 300 mg/kg respectively. The low, medium, and high treatments were created via the addition of dried coal-tar pavement sealant to a sterile soil. At the start of the 24-day exposure, sediment from a minimally impacted local reference site containing a community of live sediment-dwelling benthic macroinvertebrates was added to each replicate. An exposure-dependent response was found for several stream health measures and for several individual taxa. There were community differences in abundance (P = 0.0004) and richness (P pavement sealants contain bioavailable PAHs that may harm aquatic environments. Copyright 2009 Elsevier Ltd. All rights reserved.

Does Fibrin Sealant Reduce Seroma after Immediate Breast Reconstruction Utilizing a Latissimus Dorsi Myocutaneous Flap?

Directory of Open Access Journals (Sweden)

Han Gyu Cha

2012-09-01

Full Text Available Background The most common complication of latissimus dorsi myocutaneous flap in breastreconstruction is seroma formation in the back. Many clinical studies have shown that fibrinsealant reduces seroma formation. We investigated any statistically significant differences inpostoperative drainage and seroma formation when utilizing the fibrin sealant on the site ofthe latissimus dorsi myocutaneous flap harvested for immediate breast reconstruction afterskin-sparing partial mastectomy.Methods A total of 46 patients underwent immediate breast reconstruction utilizing alatissimus dorsi myocutaneous island flap. Of those, 23 patients underwent the procedurewithout fibrin sealant and the other 23 were administered the fibrin sealant. All flaps wereelevated with manual dissection by the same surgeon and were analyzed to evaluate thepotential benefits of the fibrin sealant. The correlation analysis and Mann-Whitney U testwere used for analyzing the drainage volume according to age, weight of the breast specimen,and body mass index.Results Although not statistically significant, the cumulative drainage fluid volume was higherin the control group until postoperative day 2 (530.1 mL compared to 502.3 mL, but thefibrin sealant group showed more drainage beginning on postoperative day 3. The donor sitecomparisons showed the fibrin sealant group had more drainage beginning on postoperativeday 3 and the drain was removed 1 day earlier in the control group.Conclusions The use of fibrin sealant resulted in no reduction of seroma formation. Becausethe benefits of the fibrin sealant are not clear, the use of fibrin sealant must be fully discussedwith patients before its use as a part of informed consent.

A review of bioceramics and fibrin sealant.

Science.gov (United States)

Le Guéhennec, L; Layrolle, P; Daculsi, G

2004-09-13

This review focuses on bone substitute composites made by mixing ceramic biomaterials with fibrin sealants. Different biomaterials such as coral, bone-derived materials, bioactive glass ceramics, and synthetic calcium phosphate have been mixed with fibrin sealant, resulting in a combination of the biological properties of the two components. This type of association has not produced identical results in all studies. In the past for some, the addition of fibrin sealant to the biomaterial failed to produce any significant, positive effect on osteointegration, whereas others found a positive impact on bone colonization. Despite the negative biological effects reported previously, bioceramic-fibrin composites have been widely used in various types of bone surgery because they are easy to manipulate. In particular, the intra-operative preparation of these composites makes it possible to add bone growth factors or autologous osteoprogenitor cells prior to bone reconstruction. The bone growth factors and autologous osteoprogenitor cells associated with the bioceramic-fibrin composites should provide surgeons with tissue engineered grafts with enhanced osteointegrative properties. This review discusses both the advantages and disadvantages, as well as the future perspectives, of using bioceramic-fibrin composites in various clinical indications.

A Review of Bioceramics and Fibrin Sealant

Directory of Open Access Journals (Sweden)

Le Guéhennec L.

2004-09-01

Full Text Available This review focuses on bone substitute composites made by mixing ceramic biomaterials with fibrin sealants. Different biomaterials such as coral, bone-derived materials, bioactive glass ceramics, and synthetic calcium phosphate have been mixed with fibrin sealant, resulting in a combination of the biological properties of the two components. This type of association has not produced identical results in all studies. In the past for some, the addition of fibrin sealant to the biomaterial failed to produce any significant, positive effect on osteointegration, whereas others found a positive impact on bone colonization. Despite the negative biological effects reported previously, bioceramic-fibrin composites have been widely used in various types of bone surgery because they are easy to manipulate. In particular, the intra-operative preparation of these composites makes it possible to add bone growth factors or autologous osteoprogenitor cells prior to bone reconstruction. The bone growth factors and autologous osteoprogenitor cells associated with the bioceramic-fibrin composites should provide surgeons with tissue engineered grafts with enhanced osteointegrative properties. This review discusses both the advantages and disadvantages, as well as the future perspectives, of using bioceramic-fibrin composites in various clinical indications.

Glass Composition for the use as a Sealant

DEFF Research Database (Denmark)

2014-01-01

The invention concerns a glass composition for the use as a sealant, particularly in a solid oxide fuel cell (SOFC) or in a solid oxide electrolyser cell (SOEC). The glass composition comprises 35-70 mol% CaO, 5-45 mol% ZnO, 5-50 mol% B2O3, 1-45 mol% SiO2, and 1 mol% or less of each element...... of the group, comprising Ba, Na and Sr, based on the total glass composition. Furthermore, the invention relates to an SOFC and an SOEC employing a sealant of said glass composition....

Treatment of venous ulcers with fibrin sealant derived from snake venom

Directory of Open Access Journals (Sweden)

MAN Gatti

2011-01-01

Full Text Available Venous ulcers of the lower limbs complicated by infection or chronicity represent a serious public health problem. The elevated number of those afflicted burdens the health services, interferes in quality of life and causes absenteeism. Although there are 2,500 items on the market, ranging from the simplest dressing up to the most complex types of dressing, treatment remains a challenge. Among the substances used, fibrin sealant is the one that promotes diminution of bacterial colonization and of edema, controls hemorrhaging, alters the pain threshold by protecting the nerve endings, hydrates the wound bed and forms granulation tissue that favors healing. Its disadvantages include higher cost and utilization of human fibrinogen that can transmit infectious diseases. The Center for the Study of Venoms and Venomous Animals (CEVAP at São Paulo State University (UNESP developed a new sealant made up of fibrinogen extracted from large animals and from an enzyme obtained from snake venom. The present study, developed in the Health Education Clinic (CEPS of Sacred Heart University (USC aimed to evaluate the effect of the new sealant on the healing process of venous ulcers in 24 adult patients, seven of whom were male and 17 female. Two study groups were formed as follows: Group 1 (G1 - control group of 11 patients treated with essential fatty acid (EFA and Unna's boot, and Group 2 (G2 - 13 patients treated with essential fatty acid (EFA, fibrin sealant and Unna's boot. The follow-up lasted eight weeks and the sealant was applied at only the first and fourth weeks. The results showed that Group 2 presented worse lesion conditions as to healing, but, when comparing the two groups, it was noteworthy that the the sealant was effective in healing venous ulcers. There is evidence that the new sealant is recommended for leg ulcers with the following advantages: ease of application, preparation of the wound bed, diminution of pain and a higher number of

Evaluation of pavement joint sealants :a new testing technique

OpenAIRE

Abo-Qudais, Saad A.

1992-01-01

A new method to evaluate the performance of sealants, used in rigid pavement joints, was developed. A special fixture was designed to transfer cyclic in-line deflection, applied by a testing machine, to cyclic normal and shear deflections on a sealant sandwiched between two-2 x 2 x 2 in. portland cement mortar cubes. The normal and shear deflections were applied simultaneously at a specific ratio controlled by the developed fixture. The new testing method simulates field ...

A comparison between three different pit and fissure sealants with regard to marginal integrity.

Science.gov (United States)

Fernandes, Kristlee Sabrin; Chalakkal, Paul; de Ataide, Ida de Noronha; Pavaskar, Rajdeep; Fernandes, Precylia Philo; Soni, Harleen

2012-04-01

THE AIM OF THIS STUDY IS TO COMPARE THE OCCURRENCE OF ENAMEL FRACTURES, SEALANT FRACTURES AND MARGINAL FISSURES AFTER PLACEMENT OF THREE SEALANTS: Helioseal F, Conseal F and Clinpro. Thirty individuals between 13 and 15 years of age, diagnosed with pit and fissure caries by visual and DIAGNOdent examination, were chosen for sealant placement on their mandibular molars. The sealants were placed at random, after which, impressions were made with polyvinyl siloxane and casts were fabricated. Dies were prepared, each of which were sputter coated with gold in order to be examined under a scanning electron microscope. The following morphologies were analyzed from dies from each of the sealant groups: Continuous margins, sealant fractures, marginal fissures and enamel fractures. After six months, they were recalled for impression making. Dies were prepared and microscopically analyzed as mentioned. Based on the time of evaluation, there were two groups: Initial group (soon after placement) and final group (after six months). Statistical analysis was done using the paired 't' test and One-way analysis of variance (ANOVA). Clinpro had the greatest fracture resistance, followed by Conseal F and Helioseal F. The occurrence of marginal fissure was found to be least with Clinpro.

Impact of adhesive and photoactivation method on sealant integrity and polymer network formation

Directory of Open Access Journals (Sweden)

Boniek Castillo Dutra Borges

2012-06-01

Full Text Available We evaluated the influence of photoactivation method and hydrophobic resin (HR application on the marginal and internal adaptation, hardness (KHN, and crosslink density (CLD of a resin-based fissure sealant. Model fissures were created in bovine enamel fragments (n = 10 and sealed using one of the following protocols: no adhesive system + photoactivation of the sealant using continuous light (CL, no adhesive system + photoactivation of the sealant using the soft-start method (SS, HR + CL, or HR + SS. Marginal and internal gaps and KHN were assessed after storage in water for 24 h. The CLD was indirectly assessed by repeating the KHN measurement after 24 h of immersion in 100% ethanol. There was no difference among the samples with regard to marginal or internal adaptation. The KHN and CLD were similar for samples cured using either photoactivation method. Use of a hydrophobic resin prior to placement of fissure sealants and curing the sealant using the soft-start method may not provide any positive influence on integrity or crosslink density.

PAH volatilization following application of coal-tar-based pavement sealant

Science.gov (United States)

Van Metre, Peter C.; Majewski, Michael S.; Mahler, Barbara J.; Foreman, William T.; Braun, Christopher L.; Wilson, Jennifer T.; Burbank, Teresa L.

2012-01-01

Coal-tar-based pavement sealants, a major source of PAHs to urban water bodies, have recently been identified as a source of volatile PAHs to the atmosphere. We tracked the volatilization of PAHs for 1 year after application of a coal-tar-based pavement sealant by measuring gas-phase PAH concentrations above the pavement surface and solid-phase PAH concentrations in sealant scraped from the surface. Gas-phase concentrations at two heights (0.03 and 1.28 m) and wind speed were used to estimate volatilization flux. The sum of the concentrations of eight frequently detected PAHs (ΣPAH8) in the 0.03-m sample 1.6 h after application (297,000 ng m-3) was about 5000 times greater than that previously reported for the same height above unsealed parking lots (66 ng m-3). Flux at 1.6 h after application was estimated at 45,000 μg m-2 h-1 and decreased rapidly during the 45 days after application to 160 μg m-2 h-1. Loss of PAHs from the adhered sealant also was rapid, with about a 50% decrease in solid-phase ΣPAH8 concentration over the 45 days after application. There was general agreement, given the uncertainties, in the estimated mass of ΣPAH8 lost to the atmosphere on the basis of air sampling (2–3 g m-2) and adhered sealant sampling (6 g m-2) during the first 16 days after application, translating to a loss to the atmosphere of one-quarter to one-half of the PAHs in the sealcoat product. Combining the estimated mass of ΣPAH8 released to the atmosphere with a national-use estimate of coal-tar-based sealant suggests that PAH emissions from new coal-tar-based sealcoat applications each year (~1000 Mg) are larger than annual vehicle emissions of PAHs for the United States.

76 FR 59087 - Approval and Promulgation of Air Quality Implementation Plans; Delaware; Adhesives and Sealants Rule

Science.gov (United States)

2011-09-23

... Promulgation of Air Quality Implementation Plans; Delaware; Adhesives and Sealants Rule AGENCY: Environmental... manufacture, sale, use, or application of adhesives, sealants, primers, and solvents. This action is being... consists of Delaware's regulation for reducing VOCs from commercially-used adhesive and sealant products by...

Do fibrin sealants impact negative outcomes after robot-assisted partial nephrectomy?

Science.gov (United States)

Cohen, Jason; Jayram, Gautam; Mullins, Jeffrey K; Ball, Mark W; Allaf, Mohamad E

2013-10-01

Contemporary rates of postoperative hemorrhage after partial nephrectomy (PN) are low. Commercially available hemostatic agents are commonly used during this surgery to reduce this risk despite a paucity of data supporting the practice. We assessed the impact of fibrin sealant hemostatic agents, a costly addition to surgeries, during robot-assisted partial nephrectomy (RAPN). Between 2007 and 2011, 114 consecutive patients underwent RAPN by a single surgeon (MEA). Evicel fibrin sealant was used in the first 74 patients during renorraphy. The last 40 patients had renorraphy performed without the use of any hemostatic agents. Clinicopathologic, operative, and complication data were compared between groups. Multivariate and univariate logistic regression analysis was performed to test the association between the use of fibrin sealants and operative outcomes. Patient demographic data and clinical tumor characteristics were similar between groups. The use of fibrin sealant did not increase operative time (166.3 vs 176.1 minutes, P=0.28), warm ischemia time (WIT) (14.4 vs 16.1 minutes, P=0.18), or length of hospital stay (2.6 vs 2.4 days, P=0.35). The omission of these agents did not increase estimated blood loss (116.6 vs 176.1 mL, P=0.8) or postoperative blood transfusion (0% vs 2.5%, P=0.17). Univariate analysis demonstrated no association between use of fibrin sealants and increased complications (P>0.05). Multivariable logistic regression showed no statistically significant predictive value of omission of hemostatic agents for perioperative outcomes (P>0.05). Perioperative hemorrhage and other major complications after contemporary RAPN are rare in experienced hands. In our study, the use of fibrin sealants during RAPN does not decrease the rate of complications, blood loss, or hospital stay. Furthermore, no impact is seen on operative time, WIT, or other negative outcomes. Omitting these agents during RAPN could be a safe, effective, cost-saving measure.

Estimating emissions from adhesives and sealants uses and manufacturing for environmental risk assessments.

Science.gov (United States)

Tolls, Johannes; Gómez, Divina; Guhl, Walter; Funk, Torsten; Seger, Erich; Wind, Thorsten

2016-01-01

Regulation (EC) No 1907/2006 concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) requires that environmental exposure assessments be performed for all uses of dangerous substances that are marketed in the European Union in quantities above 10 tons per year. The quantification of emissions to the environment is a key step in this process. This publication describes the derivation of release factors and gives guidance for estimating use rates for quantifying the emissions from the manufacturing and application of adhesives and sealants. Release factors available for coatings and paints are read across to adhesives or sealants based on similarities between these 2 product groups with regard to chemical composition and to processing during manufacturing and application. The granular emission scenarios in these documents are mapped to the broad emission scenarios for adhesives or sealants. According to the mapping, the worst-case release factors for coatings or paints are identified and assigned to the adhesives or sealants scenarios. The resulting 10 specific environmental release categories (SPERCs) for adhesives and sealants are defined by differentiating between solvent and nonsolvent ingredients and between water-borne and solvent-borne or solvent-free products. These cover the vast majority of the production processes and uses and are more realistic than the 5 relevant emission estimation defaults provided in the REACH guidance. They are accompanied with adhesive or sealant consumption rates in the EU and with guidance for estimating conservative substance use rates at a generic level. The approach of combining conservative SPERC release factors with conservative estimates of substance rates is likely to yield emission estimates that tend to overpredict actual releases. Because this qualifies the approach for use in lower-tier environmental exposure assessment, the Association of the European Adhesive & Sealant Industry

Retention of fissure sealants in young permanent molars affected by dental fluorosis: a 12-month clinical study.

Science.gov (United States)

Hasanuddin, S; Reddy, E R; Manjula, M; Srilaxmi, N; Rani, S T; Rajesh, A

2014-10-01

To evaluate and compare retention and caries occurance following placement of Clinpro and FUJI VII fissure sealants, by two different techniques simultaneously in unsealed, contralateral young permanent molars of 7- to 10-year-old children affected by mild to moderate dental fluorosis at various recall intervals of 1 week, 1, 3, 6 and 12 months. 80 schoolchildren with mild to moderate dental fluorosis were assigned to Group A and Group B with 40 children in each group. In Group A Clinpro fissure sealant and in Group B Fuji VII fissure sealant was used. In both the groups fissure sealants were applied by conventional fissure sealant technique (CST) on one side and enameloplasty sealant technique (EST) on the other side of the same arch. The applied fissure sealants were evaluated clinically for retention and caries incidence. Clinpro fissure sealant showed a retention rate of 95% when compared with Fuji VII (57.5%) at the end of 12 months, which was statistically significant. Regarding techniques, EST showed better results than CST in both the groups. Comparison of groups with respect to retention and techniques at different time periods was performed using Mann-Whitney U test (p < 0.05). Comparison of different time periods with respect to retention and technique in all the groups was performed using Wilcoxon matched pairs test by ranks (p < 0.05). Clinpro fissure sealant showed better retention at all treatment intervals, when compared with Fuji VII. Further follow-up is required to study the efficacy of the fissure sealant placement techniques.

Applying psychological theories to evidence-based clinical practice: identifying factors predictive of placing preventive fissure sealants

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Maclennan Graeme

2010-04-01

Full Text Available Abstract Background Psychological models are used to understand and predict behaviour in a wide range of settings, but have not been consistently applied to health professional behaviours, and the contribution of differing theories is not clear. This study explored the usefulness of a range of models to predict an evidence-based behaviour -- the placing of fissure sealants. Methods Measures were collected by postal questionnaire from a random sample of general dental practitioners (GDPs in Scotland. Outcomes were behavioural simulation (scenario decision-making, and behavioural intention. Predictor variables were from the Theory of Planned Behaviour (TPB, Social Cognitive Theory (SCT, Common Sense Self-regulation Model (CS-SRM, Operant Learning Theory (OLT, Implementation Intention (II, Stage Model, and knowledge (a non-theoretical construct. Multiple regression analysis was used to examine the predictive value of each theoretical model individually. Significant constructs from all theories were then entered into a 'cross theory' stepwise regression analysis to investigate their combined predictive value Results Behavioural simulation - theory level variance explained was: TPB 31%; SCT 29%; II 7%; OLT 30%. Neither CS-SRM nor stage explained significant variance. In the cross theory analysis, habit (OLT, timeline acute (CS-SRM, and outcome expectancy (SCT entered the equation, together explaining 38% of the variance. Behavioural intention - theory level variance explained was: TPB 30%; SCT 24%; OLT 58%, CS-SRM 27%. GDPs in the action stage had significantly higher intention to place fissure sealants. In the cross theory analysis, habit (OLT and attitude (TPB entered the equation, together explaining 68% of the variance in intention. Summary The study provides evidence that psychological models can be useful in understanding and predicting clinical behaviour. Taking a theory-based approach enables the creation of a replicable methodology for

Caries detection methods : Can they aid decision making for invasive sealant treatment?

NARCIS (Netherlands)

Pereira, AC; Verdonschot, EH; Huysmans, M

2001-01-01

The decision to place sealants is a difficult one, and it has been suggested that in a low risk population it may be efficient to wait until caries is detected in the fissure. An invasive sealant technique with fissure preparation may then be indicated. The diagnostic method used in the indication

Microtensile Bond Strength of Embrace Wetbond Hydrophilic Sealant in Different Moisture Contamination: An In-Vitro Study.

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Panigrahi, Antarmayee; Srilatha, K T; Panigrahi, Rajat G; Mohanty, Susant; Bhuyan, Sanat K; Bardhan, Debojyoti

2015-07-01

Contamination of etched enamel with saliva has been shown to result in sealant failure. Recently, a hydrophilic sealant has been introduced. In absence of documented literature, this in vitro study was undertaken to ascertain the efficacy of Embrace Wet Bond without reduction of microtensile bond strength in the different moisture contamination. A 5mm block of sealant were built over prepared occlusal surface of 40 non-carious therapeutically extracted third molars which were sectioned into 1mm thick stick and tested using Zwick micro tensile tester. Obtained data were subjected to descriptive analysis, one-way ANOVA and Scheffe's post-hoc tests. Mean microtensile bond strength of Embrace sealant was not significantly lowered in different moisture contamination groups except Group 3 (air drying), which showed very highly significant (p<0.001) decrease in μTBS as compared to Group 1 (non-contaminated). Mean μTBS of Embrace sealant remains largely unchanged even in presence of moisture. Owing to its hydrophilic property, this sealant can be a great help in cases where maintaining isolation is difficult.

Comparison of various concentrations of tricalcium phosphate nanoparticles on mechanical properties and remineralization of fissure sealants.

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Sara Tavassoli-Hojjati

2014-08-01

Full Text Available The aim of this study was to investigate the mechanical properties (flexural strength, micro-shear bond strength and remineralizing potential of fissure sealants by adding various concentrations of β-tricalcium phosphate nanoparticles.This in-vitro study consisted of five experimental groups containing prepared nano-fisssure sealants (1-5 wt.% β-TCP nanoparticles and two control groups containing a prepared and a commercial fissure sealant. Flexural/micro-shear bond strength values were measured using Zwick test machine. Cavities on sixty healthy premolar teeth were filled with the fissure sealants containing 0-5 wt.% of nano β-TCP. The samples were assessed for remineralization under scanning electron microscopy (SEM and EDAX. Kolmogorov-Smirnov test, One-way ANOVA and Tukey's Post Hoc analysis/HSD were used to analyze the data.There was no significant difference between the flexural strengths/elastic modulus of the 0-5 wt.% nano β-TCP groups (p>0.05. The average flexural strength/elastic modulus of the prepared fissure sealant group (0% was significantly higher than the commercial fissure sealant group (Clinpro (p0.05. Examining the samples under SEM showed a significant increase in thickness of the intermediate layer with increasing concentrations of β-TCP nanoparticles (p<0.05.Addition of 1-5 wt.% β-TCP nanoparticles to the fissure sealants significantly increased the remineralization potential without affecting the mechanical properties.

Safety and usability of hemostats, sealants, and adhesives.

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Burks, Sandra; Spotnitz, William

2014-08-01

Hemostats, sealants, and adhesives are an integral part of surgical patient care. Nurses who have knowledge about these agents can better help ensure safe, efficient surgical patient care. As a caregiver and patient advocate, the perioperative nurse must understand the most current information about these agents and be prepared to facilitate the transfer of this knowledge to all caregivers. Information about these agents, including the contraindications, warnings, and precautions associated with their use as well as their preparation and application, is provided here. Algorithms designed to clarify the best options for using hemostats, sealants, and adhesives are included as well. Copyright © 2014 AORN, Inc. Published by Elsevier Inc. All rights reserved.

[Eosinophilic pleural effusion possibly induced by fibrin sealant].

Science.gov (United States)

Kambayashi, Takatoyo; Suzuki, Takashi

2012-02-01

A 74-year-old man underwent right upper lobectomy for the lung cancer and bullectomy of right lower lobe. Fibrin sealant was used for sealing the excision line. The increase of the pleural effusion with increasing C-reactive protein( CRP) and eosinophilia was noted at the 17th day after the operation. The pleural effusion was transparent and yellowish colored suggesting transudatory liquid. The eosinophil in the pleural effusion was as high as 14%. The drainage of the pleural effusion was performed for 2 days resulting in disappearing the abnormal accumulation without any additional treatment. The cause of pleural effusion was supposed to be fibrin sealant by a positive result of the drug lymphocyte stimulation test.

Causes of poor sealant performance in soil-gas-resistant foundations

International Nuclear Information System (INIS)

Scott, A.

1994-01-01

Sealants for radon-resistant foundation construction must seal the gap between concrete sections. Modern sealants have such low permeability that seal performance depends only on the permeability of the material that contacts the sealant. The surface permeability of concrete walls and floors was measured by a specially designed permeameter, which measures the airflow induced by a pressure difference across a temporary test seal applied to the surface. The permeability of bulk concrete is about 10 -15 m 2 . Areas free of surface defects had surface permeability ranging from 10 -14 to 10 -16 m 2 . However, surface defects are common on concrete wall surfaces, which increase the permeability to >10 -12 m 2 , too high for standard seal designs to be adequate as the only method of soil gas and radon exclusion. Radon-resistant seals require either extended contact widths or mechanical removal of the surface layer and defects. (au) (4 refs.)

Bisphenol A in dental sealants and its estrogen like effect

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Manu Rathee

2012-01-01

Full Text Available Bisphenol A or BPA-based epoxy resins are widely used in the manufacture of commercial products, including dental resins, polycarbonate plastics, and the inner coating of food cans. BPA is a precursor to the resin monomer Bis-GMA. During the manufacturing process of Bis-GMA dental sealants, Bisphenol A (BPA might be present as an impurity or as a degradation product of Bis-DMA through esterases present in saliva. Leaching of these monomers from resins can occur during the initial setting period and in conjunction with fluid sorption and desorption over time and this chemical leach from dental sealants may be bioactive. Researchers found an estrogenic effect with BPA, Bis-DMA, and Bis-GMA because BPA lacks structural specificity as a natural ligand to the estrogen receptor. It generated considerable concern regarding the safety of dental resin materials. This review focuses on the BPA in dental sealants and its estrogen-like effect.

Low-cost glass ionomer cement as ART sealant in permanent molars: a randomized clinical trial

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Daniela HESSE

2015-01-01

Full Text Available Clinical trials are normally performed with well-known brands of glass ionomer cement (GIC, but the cost of these materials is high for public healthcare in less-affluent communities. Given the need to research cheaper materials, it seems pertinent to investigate the retention rate of a low-cost GIC applied as atraumatic restorative treatment (ART sealants in two centers in Brazil. Four hundred and thirty-seven 6-to-8-year-old schoolchildren were selected in two cities in Brazil. The children were randomly divided into two groups, according to the tested GIC applied in the first permanent molars. The retention rate was evaluated after 3, 6 and 12 months. Kaplan-Meier survival analysis and the log-rank test were performed. The variables were tested for association with sealant longevity, using logistic regression analyses (α = 5%. The retention rate of sealants after 12 months was 19.1%. The high-cost GIC brand presented a 2-fold-more-likely-to-survive rate than the low-cost brand (p < 0.001. Significant difference was also found between the cities where the treatments were performed, in that Barueri presented a higher sealant survival rate than Recife (p < 0.001. The retention rate of a low-cost GIC sealant brand was markedly lower than that of a well-known GIC sealant brand.

Hemostats, sealants, and adhesives: components of the surgical toolbox.

Science.gov (United States)

Spotnitz, William D; Burks, Sandra

2008-07-01

The surgical toolbox is expanding, and newer products are being developed to improve results. Reducing blood loss so that bloodless surgery can be performed may help minimize morbidity and length of stay. As patients, hospital administrators, and government regulators desire less invasive procedures, the surgical technical challenge is increasing. More operations are being performed through minimally invasive incisions with laparoscopic, endoscopic, and robotic approaches. In this setting, tools that can reduce bleeding by causing blood to clot, sealing vessels, or gluing tissues are gaining an increasing importance. Thus, hemostats, sealants, and adhesives are becoming a more important element of surgical practice. This review is designed to facilitate the reader's basic knowledge of these tools so that informed choices are made for controlling bleeding in specific clinical situations. Such information is useful for all members of the operative team. The team includes surgeons, anesthesiologists, residents, and nurses as well as hematologists and other medical specialists who may be involved in the perioperative care of surgical patients. An understanding of these therapeutic options may also be helpful to the transfusion service. In some cases, these materials may be stored in the blood bank, and their appropriate use may reduce demand for other transfusion components. The product classification used in this review includes hemostats as represented by product categories that include mechanical agents, active agents, flowables, and fibrin sealants; sealants as represented by fibrin sealants and polyethylene glycol hydrogels; and adhesives as represented by cyanoacrylates and albumin cross-linked with glutaraldehyde. Only those agents approved by the Food and Drug Administration (FDA) and presently available (February 2008) for sale in the United States are discussed in this review.

Percutaneous treatment of femoral pseudoaneurysms: comparison of fibrin sealant against thrombin

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Daniel Mendes Pinto

2013-12-01

Full Text Available INTRODUCTION: Femoral pseudoaneurysms are a complication that occurs in connection with up to 8% of percutaneous procedures. Of the available treatments, ultrasound guided thrombin injection has a high success rate and is well-tolerated by patients. The combination of thrombin and fibrinogen known as fibrin sealant forms a stable clot and can be used to treat pseudoaneurysms, particularly those with complex anatomy and larger size. OBJECTIVE: To compare the results of treating femoral pseudoaneurysm in two ways: Group T was treated with thrombin alone and Group T+F was treated with fibrin sealant (thrombin+fibrinogen. METHODS: A retrospective analysis was conducted of femoral pseudoaneurysm cases treated between January 2005 and December 2012. RESULTS: Twenty-eight patients were treated, 21 with thrombin alone and seven with fibrin sealant. All patients in group T were treated successfully, but only four patients in group T+F were treated successfully (57.1% success rate in Group T+F, p<0.01. The three cases of failure in group T+F needed surgery and in one of these cases the complication was embolization to the femoral bifurcation. The pseudoaneurysms that were treated with fibrin sealant were larger (25 cm3 in Group T and 57.7 cm3 in Group T+F, p=0.02 and required larger volumes of thrombin (0.5 mL in Group T and 1.0 mL in Group T+F, p<0.01. There was one complication in Group T and two complications in Group T+F (p<0.01. CONCLUSIONS: Irrespective of the small number of cases reviewed, treatment with thrombin alone was superior to treating with fibrin sealant, since it caused few complications and was more effective at correcting pseudoaneurysms.

A Trajectory Generation Method Based on Edge Detection for Auto-Sealant Cartesian Robot

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Eka Samsul Maarif

2014-07-01

Full Text Available This paper presents algorithm ingenerating trajectory for sealant process using captured image. Cartesian robot as auto-sealant in manufacturing process has increased productivity, reduces human error and saves time. But, different sealant path in many engine models means not only different trajectory but also different program. Therefore robot with detection ability to generate its own trajectory is needed. This paper describes best lighting technique in capturing image and applies edge detection in trajectory generation as the solution. The algorithm comprises image capturing, Canny edge detection, integral projection in localizing outer most edge, scanning coordinates, and generating vector direction codes. The experiment results show that the best technique is diffuse lighting at 10 Cd. The developed method gives connected point to point trajectory which forms sealant path with a point to next point distance is equal to 90° motor rotation. Directional movement for point to point trajectory is controlled by generated codes which are ready to be sent by serial communication to robot controller as instruction for motors which actuate axes X and Y directions.

Prevention of lymphocele by using gelatin-thrombin matrix as a tissue sealant after pelvic lymphadenectomy in patients with gynecologic cancers: a prospective randomized controlled study.

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Kim, Yun Hwan; Shin, Hyun Joo; Ju, Woong; Kim, Seung Cheol

2017-05-01

This prospective randomized controlled pilot study aimed to find whether gelatin-thrombin matrix used as a tissue sealant (FloSeal) can prevent the occurrence of pelvic lymphocele in patients with gynecologic cancer who has undergone pelvic lymphadenectomy. Each patient, who undergo a laparotomic pelvic lymph node dissection on both sides, was randomly assigned for FloSeal application on 1 side of the pelvis. The other side of the pelvis without any product application being the control side. The amount of lymph drainage at each side of the pelvis was measured for 3 days, and computed tomography scans were obtained 7 days and 6 months after surgery for detection of pelvic lymphocele. Among 37 cases, the median amount of lymph drainage was significantly decreased in the hemi-pelvis treated with FloSeal compared to the control hemi-pelvis (p=0.025). The occurrence of lymphocele was considerably reduced in treated hemi-pelvis (8/37, 21.6%) compared with control hemi-pelvis (12/37, 32.4%) after 7 post-operative days (p=0.219), and more decreased in the treated hemi-pelvis (5/37, 13.5%) compared with control hemi-pelvis (9/37, 24.3%) after postoperative 6 months (p=0.344). The application of FloSeal as a tissue sealant in lymph nodes resected tissues can reduce the incidence of pelvic lymphocele in gynecologic cancer patients. A large randomized controlled study could confirm these preliminary results. Copyright © 2017. Asian Society of Gynecologic Oncology, Korean Society of Gynecologic Oncology

An accelerated exposure and testing apparatus for building joint sealants.

Science.gov (United States)

White, C C; Hunston, D L; Tan, K T; Hettenhouser, J; Garver, J D

2013-09-01

The design, fabrication, and implementation of a computer-controlled exposure and testing apparatus for building joint sealants are described in this paper. This apparatus is unique in its ability to independently control and monitor temperature, relative humidity, ultraviolet (UV) radiation, and mechanical deformation. Each of these environmental factors can be controlled precisely over a wide range of conditions during periods of a month or more. Moreover, as controlled mechanical deformations can be generated, in situ mechanical characterization tests can be performed without removing specimens from the chamber. Temperature and humidity were controlled during our experiments via a precision temperature regulator and proportional mixing of dry and moisture-saturated air; while highly uniform UV radiation was attained by attaching the chamber to an integrating sphere-based radiation source. A computer-controlled stepper motor and a transmission system were used to provide precise movement control. The reliability and effectiveness of the apparatus were demonstrated on a model sealant material. The results clearly show that this apparatus provides an excellent platform to study the long-term durability of building joint sealants.

Effectiveness of a new gelatin sealant system for dural closure.

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Kawai, Hisashi; Nakagawa, Ichiro; Nishimura, Fumihiko; Motoyama, Yasushi; Park, Young-Su; Nakamura, Mitsutoshi; Nakase, Hiroyuki; Suzuki, Shuko; Ikada, Yoshito

2014-10-01

Watertight dural closure is imperative after neurosurgical procedures because inadequately treated leakage of cerebrospinal fluid (CSF) can have serious consequences. In this study, the authors test the use of a new gelatin glue as a dural sealant in in vitro and in vivo canine models of transdural CSF leakage. The in vitro model was sutured semicircles of canine dura mater and artificial dural substitute. The sutures were sealed with gelatin glue (n  =  20), fibrin glue (n  =  20), or a polyethylene glycol (PEG)-based hydrogel sealant (n  =  20). Each sample was set in a device to measure water pressure, and pressure was increased until leakage occurred. Bonding strength was subjectively evaluated. The in vivo model was dogs who underwent dural excision and received either no sealant (control group; n  =  5) or gelatin glue sealant (n  =  5) before dural closure. Twenty-eight days post-surgery, the maximum intracranial pressure was measured at the cisterna magna using Valsalva maneuver and tissue adhesion was evaluated. The water pressure at which leakage occurred in the in vitro model was higher with gelatin glue (76·5 ± 39·8 mmHg) than with fibrin glue (38·3 ± 27·4 mmHg, P control group (13·8 ± 4·0 mmHg, P control group (P  =  0·005). The new gelatin glue provides an effective watertight closure when used as an adjunct to sutured dural repair.

Comparative efficacy of nanofilled and microfilled resin-modified glass ionomer as pits and fissure sealant in permanent molar teeth

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Manzuma Akhter Zakaria

2017-05-01

Full Text Available The purpose of the present study was to compare the efficacy of nanofilled and microfilled resin- modified glass ionomer as pits and fissure sealants in permanent molar teeth. Ninety six teeth having fissure at the occlusal surface were randomly divided into two groups: Group I: Treated by nanofilled resin-modified glass ionomer sealant and Group II: Treated by microfilled resin- modified glass ionomer sealants. Clinical assessment was performed by modified Ryge´s criteria by means of retention, color match, marginal adaptation at 3, 6, and 12 months follow-up visit. Chi-square test was used for testing differences between the two groups; a value of p<0.05 was considered as statistically significant. The results revealed that at 12 months observation period, nanofilled resin-modified glass ionomer sealant showed better retention, color stability and marginal adaptation than that of microfilled resin-modified glass ionomer sealants. Furthermore, the differences between two groups in respect to marginal adaptation and color match were statistically significant (p<0.05. It can be concluded that nanofilled resin-modified glass ionomer sealant could be a better alternative to microfilled resin- modified glass ionomer sealant.

Microleakage assessment of fissure sealant following fissurotomy bur or pumice prophylaxis use before etching

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Ali Bagherian

2013-01-01

The aim of this investigation was to compare the microleakage level of fissure sealants prepared by a fissurotomy bur or pumice prophylaxis prior to acid etching. Materials and Methods: Ninety freshly extracted healthy maxillary premolar teeth were randomly selected for this investigation. Teeth were then divided into three fissure sealant preparatory groups of A: Fissurotomy bur + acid etch; B: Pumice prophylaxis + acid etch and C: Acid etch alone. Sealant was applied to the occlusal fissures of all specimens using a plastic instrument. This was to avoid any air trap under the sealant. Sample teeth were first thermocycled (1000 cycles, 20 s dwell time and then coated with two layers of nail varnish leaving 2 mm around the sealant. This was then followed by immersion in basic fuchsin 3%. Processed teeth were sectioned longitudinally and examined under a stereomicroscope for microleakage assessment using a score of 0-3. Collected data was then subjected to Kruskall-Wallis Analysis of Variance and Mann-Whitney U-test. P < 0.05 was considered as significant. Results: Teeth in fissurotomy bur and pumice prophylaxis groups had significantly reduced level of microleakage than those in acid etch alone (P = 0.005 and P = 0.003, respectively. Conclusion: Use of fissurotomy bur and pumice prophylaxis accompanied with acid etching appears to have a more successful reduction of microleakage than acid etch alone.

Measuring quality of dental care: Caries prevention services for children.

Science.gov (United States)

Herndon, Jill Boylston; Tomar, Scott L; Catalanotto, Frank A; Rudner, Nancy; Huang, I-Chan; Aravamudhan, Krishna; Shenkman, Elizabeth A; Crall, James J

2015-08-01

The authors conducted a study to validate the following 3 evidence-based, process-of-care quality measures focused on dental caries prevention for children with an elevated risk of experiencing caries: sealants for 6- to 9-year-olds, sealants for 10- to 14-year-olds, and topical fluoride. Using evidence-based guidelines, the Dental Quality Alliance developed measures for implementation with administrative data at the plan and program levels. To validate the measures, the authors used data from the Florida and Texas Medicaid programs and Children's Health Insurance Programs and from national commercial dental benefit plans. Data were extracted from 414 randomly selected dental office records to validate the use of administrative data to accurately calculate the measures. The authors also assessed statistically significant variations in overall measure performance. Agreement between administrative data and dental records was 95% for sealants (κ = 0.82) and 90% for topical fluoride (κ = 0.78). Sensitivity and specificity were 90.7% and 88.5% for topical fluoride and 77.8% and 98.8% for sealants, respectively. Variation in overall measure performance was greatest for topical fluoride (χ(2) = 5,887.1; P caries received at least 2 topical fluoride applications during the reporting year. Although there was greater variation in performance for sealants for 6- to 9-year-olds (range, 21.0-31.3%; χ(2) = 548.6; P caries prevention process-of-care quality measures can be implemented feasibly and validly using administrative claims data. The measures can be used to assess, monitor, and improve the proportion of children with an elevated risk of experiencing dental caries who receive evidence-based caries prevention services. Copyright © 2015 American Dental Association. Published by Elsevier Inc. All rights reserved.

Use of fibrin sealants for the localized, controlled release of cefazolin

Science.gov (United States)

Tredwell, Stephen; Jackson, John K.; Hamilton, Donald; Lee, Vivian; Burt, Helen M.

2006-01-01

Background Fibrin sealants are used increasingly in surgery to reduce bleeding and improve wound healing. They have great potential as biocompatible, biodegradable drug delivery systems, because the sealant may adhere to the target tissue and allow controlled release of the drug over an extended period. We investigated the encapsulation, stability and controlled release of erythromycin and cefazolin from Beriplast fibrin sealants (Aventis Behring Canada). Methods Drug-loaded clots were cast in glass vials and allowed to set. We observed the clots for drug precipitation and aggregation, and we assessed the effect of drug encapsulation on clot strength. Drug stability and release from the clots in phosphate buffered saline (PBS) was quantified by ultraviolet and visible violet absorbance spectroscopy and high-performance liquid chromatography. Results Erythromycin was found to release slowly from the fibrin clots over the first 2 hours but then degrade rapidly. Cefazolin was found to be very stable in clots in PBS (97% stable at 2 d and 93% stable at 5 d). The drug released in a controlled manner over 2 days, with most being released during the first day. The dose of drug released could be varied by changing the amount placed in the thrombin solution. Clot thickness had no effect on the rate of cefazolin release. Conclusion Overall, the 2-day release profile and the excellent stability of the drug suggest that cefazolin-loaded fibrin sealants may offer an effective route of postoperative antibiotic delivery. PMID:17152573

76 FR 79537 - Approval and Promulgation of Air Quality Implementation Plans; Delaware; Adhesives and Sealants Rule

Science.gov (United States)

2011-12-22

... Promulgation of Air Quality Implementation Plans; Delaware; Adhesives and Sealants Rule AGENCY: Environmental..., sale, use, or application of adhesives, sealants, primers, and solvents. EPA is approving this SIP... miscellaneous industrial adhesives control techniques guideline (CTG) category in accordance with the...

Polychlorinated biphenyls in polysulfide sealants-Occurrence and emission from a landfill station

International Nuclear Information System (INIS)

Persson, N. Johan; Pettersen, Harald; Ishaq, Rasha; Axelman, Johan; Bandh, Cecilia; Broman, Dag; Zebuehr, Yngve; Hammar, Tommy

2005-01-01

Approximately 80 000 kg polysulfide sealant containing 10 000-18 000 kg polychlorinated biphenyls (PCB) was deposited at a Swedish municipal landfill station during 1965-1973. Investigations during 1994 showed that soil layers underneath the landfill had concentration of PCB not alarmingly high. The concentration of PCB congeners in ground water samples was elevated 4-750 times compared to a reference sample. Based on samples of ground water, leachate water, and flux chambers measuring evaporation of PCB from the landfill surface, the emission of PCB was estimated to be 1 g ΣPCB/yr. This very low rate was attributed to the high sorptive capacity of the sealant. Compared to a reference site, the evaporation flux was elevated for the most volatile congeners, but factors 20-1400 lower than from another landfill which was contaminated with PCB in paper-pulp fibres. - From a municipal 2-ha landfill containing 10-18 tonnes of ΣPCB bound in polysulfide sealants, only 1 g per year escape to the surroundings

76 FR 64237 - Approval and Promulgation of Air Quality Implementation Plans; Maryland; Adhesives and Sealants Rule

Science.gov (United States)

2011-10-18

...-9480-5] Approval and Promulgation of Air Quality Implementation Plans; Maryland; Adhesives and Sealants... chemical production and polytetrafluoroethylene operations; from paint, resin, and adhesive manufacturing; and from adhesive and sealant application. This SIP revision also pertains to an addition of a new...

A reversible thermoresponsive sealant for temporary closure of ocular trauma.

Science.gov (United States)

Bayat, Niki; Zhang, Yi; Falabella, Paulo; Menefee, Roby; Whalen, John J; Humayun, Mark S; Thompson, Mark E

2017-12-06

Open globe injuries are full-thickness injuries sustained to the eye wall (cornea or sclera), which cause immediate drops in intraocular pressure that may lead to retinal detachment and permanent vision loss if not treated rapidly after injury. The current standard of care for open globe injuries consists of suturing the margins closed, but the technique can be time-consuming, requires specialized training and equipment, and can lead to patient discomfort, abrasion, and infection from eye rubbing. We engineered an injectable, thermoresponsive sealant (TRS) and a custom tool to occlude open globe injuries. The smart hydrogel sealant consists of physically cross-linked N -isopropylacrylamide copolymerized with butylacrylate. At low temperatures, it can be injected as a liquid, and when raised to body temperature, a heat-induced gelation converts the hydrogel into a solidified occlusion. The sealant can be repositioned or removed without causing additional trauma via exposure to cold water. In vitro and ex vivo assessments of mechanical adhesion to eye tissue revealed maintenance of intraocular pressure that is five times greater than the physiological range with reversible seal strength comparable to cyanoacrylate (super glue). In vivo assessment in a rabbit model of ocular trauma demonstrated ease of use for TRS deployment, statistically significant improvement in wound sealing, and no evidence of neurotoxicity, retinal tissue degradation, or significant chronic inflammatory response after 30 days of exposure. Given the advantages of body heat-induced gelation, rapid reversible occlusion, and in vivo safety and efficacy, shape-adaptable TRSs have translational potential as smart wound sealants for temporary occlusion of surgical incisions or traumatic injuries. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Polychlorinated biphenyls (PCBs) in indoor air originating from sealants in contaminated and uncontaminated apartments within the same housing estate

DEFF Research Database (Denmark)

Frederiksen, Marie; Meyer, Harald William; Ebbehøj, Niels Erik

2012-01-01

. The PCB(tot) levels in the air of the contaminated section were 168-3843 ng m(-3) (mean: 1030 ng m(-3)), while the mean levels in the reference apartments were 6.03 ng m(-3). The sum of the 24 measured PCB congeners in sealants from the contaminated section was 187-221680 mg kg(-1). Principal component......Twenty-four congeners of polychlorinated biphenyls (PCBs) were measured in 83 air samples and 20 elastic sealants samples of apartments with PCB-containing sealants. In addition, PCBs were measured in 21 air samples from reference apartments located in an uncontaminated section of the same estate...... analysis revealed four groups among the sealant samples with different congener compositions, only two of which were clearly similar to known PCB mixtures, while two were not. Significant correlations and intercorrelations were observed between the lower chlorinated congeners in air and sealant, e...

Fibrin sealant for mesh fixation in laparoscopic groin hernia repair does not increase long-term recurrence

DEFF Research Database (Denmark)

Fenger, Andreas Qwist; Helvind, Neel Maria; Pommergaard, Hans-Christian

2016-01-01

BACKGROUND: Methods of groin hernia repair include laparoscopic techniques using tissue-penetrating mesh fixation or non-penetrating fixation. Concerns regarding hernia repair include postoperative chronic pain, sexual dysfunction, and recurrence. Earlier estimations of recurrence rates have......) laparoscopic groin hernia repair using either fibrin sealant or tacks for mesh fixation. METHODS: This study used data from the Danish Hernia Database to create the following cohort: All patients operated laparoscopically for primary groin hernia with a TAPP procedure using fibrin sealant for mesh fixation...... difference in long-term reoperation rates and clinical recurrences in patients undergoing TAPP repair with meshes fixated with fibrin sealant compared with tacks....

Migration of PCBs from Sealants to Adjacent Material

DEFF Research Database (Denmark)

Andersen, Helle Vibeke; Gunnarsen, Lars Bo; Kampmann, Kristoffer

2015-01-01

PCB in sealants can migrate into porous surfaces like concrete and brick and contaminate these materials. The study focuses on an analysis of concentration profiles in relation to alleviation of PCB contamination. The PCB content was determined in 20 samples of concrete and 6 samples of brick adj...

Clinical Evaluation of applying a hydrophobic and a hydrophilic bonding agent on the retention and durability of fissure sealant therapy

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Mostafa GHandi

2016-03-01

Full Text Available Background and Aims: As in fissure sealant therapy the tooth surface is mostly enamel, the use of an enamel bonding agent (hydrophobic bonding agent may be more cost effective than that of newer generations of bonding (hydrophilic bonding agents. The aim of this study was to compare the retention and durability of fissure sealant therapy when applying an enamel bonding agent, a dentin bonding agent and no bonding agent during 4 years. Materials and Methods: This study was done on the first permanent molars of the upper and lower jaws of 24 students of the first grade of a primary school (6-7 years old. On 36 teeth, a dentin bonding agent (Excite was applied under the fissure sealant and on 36 teeth an enamel bonding agent (Margin bond was applied under the fissure sealant. Then, 24 teeth were selected from these two groups and were compared with a group (including 24 teeth with no bonding agent under the fissure sealant (as control group. All the fissures of the teeth were evaluated annually for 4 years to find out the presence or absence of fissure sealant substance. Data were analyzed using Wilcoxon test. Results: From the statistical analysis, there was no significant difference in retention and durability of the fissure sealant substance comparing the group with dentin bonding agent (Excite and the group with enamel bonding agent (Margin bond. Also, using a bonding agent made no significant difference (P>0.05. Conclusion: According to the results of this study, using a bonding agent made no improvement in the retention and durability of fissure sealant substance.

Transcutaneous Drainage of Gel-Like Substance after Application of Hydrogel Dural Sealant: Report of Two Cases.

Science.gov (United States)

Siman, Homayoun; Techy, Fernando

2016-02-01

Study Design Case report. Objective Incidental durotomy (IDT) is a common complication of spinal surgery. The use of collagen matrix graft along with hydrogel dural sealant is a common method of IDT repair. With this method, there have been several reported cases of detrimental dural sealant expansion in the literature. One case study reported an expansion rate greater than 300%; many report neurologic damage. This article reports the clinical course of two patients who developed postoperative transcutaneous drainage of a gel-like substance after the use of a dural sealant, which is a previously unreported complication. Methods The clinical course and treatment outcome of two patients is presented. Results Both patients experienced postoperative transcutaneous drainage of a gel-like substance at the surgical site. Case one began draining this substance on postoperative day 14. This patient required no further intervention, and the drainage ended after 3 mL of a gel-like substance was expressed from his incision while in the clinic. Case two began draining the gel on postoperative day 16. This patient underwent two washout procedures and resolution of the drainage. No infection was ever detected. Conclusions To our knowledge, our patients are the first reported cases of transcutaneous drainage of expanded dural sealant. It is important to take into consideration the unexpected expansion of a dural sealant when using it for the repair of IDT.

Sealing effectiveness of fissure sealant bonded with universal adhesive systems on saliva-contaminated and noncontaminated enamel.

Science.gov (United States)

Memarpour, Mahtab; Shafiei, Fereshteh; Zarean, Mehran; Razmjoei, Faranak

2018-01-01

The effectiveness of sealants is dependent upon their adhesion to enamel surface. The aim of the study was to evaluate the sealing ability of a pit and fissure sealant used with a universal adhesive (etch-and-rinse vs. self-etch modes) when the site is contaminated with saliva. Adhesive properties were evaluated as microleakage and scanning electron microscopic (SEM) characteristics. A total of 72 mandibular third molars were randomly divided into 6 groups (n=12). Occlusal pits and fissures were sealed with an unfilled resin fissure sealant (FS) material with or without saliva contamination. The groups included: 1) phosphoric acid etching + FS (control), 2) phosphoric acid etching + Scotchbond Universal (etch-and-rinse) + FS, 3) phosphoric acid etching + saliva + Scotchbond Universal (etch-and-rinse) + FS, 4) Scotchbond Universal (self-etching) + FS,5) Scotchbond Universal (self-etching) + saliva + FS, and 6) Scotchbond Universal (self-etching) + saliva + Scotchbond Universal + FS. After thermocycling, the teeth were placed in 0.5% fuchsin, sectioned, and evaluated by digital microscopy. Two samples from each group were also observed by SEM. The data were analyzed with Kruskal-Wallis and Mann-Whitney tests for a significance of p universal adhesive in etch-and-rinse or self-etch modes was similar to that of conventional acid etching. Saliva contamination had a negative effect on sealant adhesion to pretreated enamel. Key words: Pit and fissure sealant, Universal adhesive, Saliva.

Dental Sealants: Knowledge, Value, Opinion, and Practice among Dental Professionals of Bathinda City, India

OpenAIRE

Asawa, Kailash; Gupta, Vivek V.; Tak, Mridula; Nagarajappa, Ramesh; Chaturvedi, Pulkit; Bapat, Salil; Mishra, Prashant; Roy, Santanu Sen

2014-01-01

Objective. The purpose of the study was to assess the knowledge, value, opinion, and practice regarding use of dental sealants among private dental practitioners in Bathinda City, Punjab, India. Materials and Methods. A cross-sectional survey was conducted among all private dental practitioners in Bathinda City, Punjab. A self-administered structured questionnaire consisting of 28 items was used to assess their knowledge, value, opinion, and practice regarding dental sealants. One-way analysi...

Evaluating cyclic fatigue of sealants during outdoor testing

Science.gov (United States)

R. Sam Williams; Steven Lacher; Corey Halpin; Christopher White

2009-01-01

A computer-controlled test apparatus (CCTA) and other instrumentation for subjecting sealant specimens to cyclic fatigue during outdoor exposure was developed. The CCTA enables us to use weather-induced conditions to cyclic fatigue specimens and to conduct controlled tests in-situ during the outdoor exposure. Thermally induced dimensional changes of an aluminum bar...

Prevention of intra-abdominal adhesion by bi-layer electrospun membrane.

Science.gov (United States)

Jiang, Shichao; Wang, Wei; Yan, Hede; Fan, Cunyi

2013-06-04

The aim of this study was to compare the anti-adhesion efficacy of a bi-layer electrospun fibrous membrane consisting of hyaluronic acid-loaded poly(ε-caprolactone) (PCL) fibrous membrane as the inner layer and PCL fibrous membrane as the outer layer with a single-layer PCL electrospun fibrous membrane in a rat cecum abrasion model. The rat model utilized a cecal abrasion and abdominal wall insult surgical protocol. The bi-layer and PCL membranes were applied between the cecum and the abdominal wall, respectively. Control animals did not receive any treatment. After postoperative day 14, a visual semiquantitative grading scale was used to grade the extent of adhesion. Histological analysis was performed to reveal the features of adhesion tissues. Bi-layer membrane treated animals showed significantly lower adhesion scores than control animals (p compared with the PCL membrane. Histological analysis of the bi-layer membrane treated rat rarely demonstrated tissue adhesion while that of the PCL membrane treated rat and control rat showed loose and dense adhesion tissues, respectively. Bi-layer membrane can efficiently prevent adhesion formation in abdominal cavity and showed a significantly decreased adhesion tissue formation compared with the control.

Subclinical and clinical mastitis in heifers following the use of a teat sealant precalving.

Science.gov (United States)

Parker, K I; Compton, C; Anniss, F M; Weir, A; Heuer, C; McDougall, S

2007-01-01

This study investigated the effect in heifers of infusion of a bismuth subnitrate teat-canal sealant and bacterial intramammary infection (IMI) precalving on prevalence of postcalving IMI and incidence of clinical mastitis in the first 2 wk postcalving. Glands (n = 1,020) from heifers (n = 255) in 5 seasonally calving, pasture-fed dairy herds were randomly assigned within heifer to 1 of 4 treatment groups (no treatment; mammary gland secretion collection; infusion of a teat sealant; or sample collection with infusion of teat sealant). Heifers within a herd were enrolled on one calendar day, 31 d on average before the planned start of the seasonal calving period. Duplicate milk samples were collected from each gland within 4 d after calving for bacterial culture. Herd owners collected duplicate milk samples, before treatment, for bacterial culture from glands they defined as having clinical mastitis. The gland prevalence of IMI precalving was 15.5% and did not differ between herds. Bacteria isolated precalving included coagulase-negative staphylococci (76.9% of all bacteriologically positive samples), Streptococcus uberis (14.1%), Staphylococcus aureus (5.1%), Corynebacterium spp. (3.8%), and others (0.1%). The presence of an IMI precalving increased the risk of an IMI postcalving 3.6-fold and the risk of clinical mastitis 4-fold, relative to no IMI precalving. Infusion of the teat sealant reduced the risk of postcalving IMI due to Strep. uberis by 84%, and of clinical mastitis by 68%. Sampling the glands precalving had no effect on postcalving IMI or on clinical mastitis incidence. Use of an internal teat canal sealant in heifers precalving may be a useful tool for reducing the risk of subclinical and clinical mastitis in heifers.

In Vitro Comparison of Microleakage of Two Materials Used as Pit and Fissure Sealants

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Zahra Bahrololoomi

2011-09-01

Full Text Available Background and aims. Marginal seal of the material is extremely important in fissure sealant therapy. The aim of this study was to investigate microleakage of flowable composite resins and conventional fissure sealants with or without dentin bonding agent. Materials and methods. The occlusal surface of 60 intact extracted human premolars, divided into four groups, were cleaned with pumice/slurry, etched with 37% phosphoric acid for 15 seconds, rinsed and dried. Groups were treated differently: Excite bonding agent followed by Helioseal F fissure sealant in group1; Helioseal F alone in group 2; Excite bonding agent followed by Tetric Flow in group 3; and Tetric Flow alone in group 4. Light-curing was done after each application. After thermocycling, the whole surface of each specimen was coated with nail varnish except for one millimeter around the fissure sealant. The teeth were immersed in 2% basic fuchsin for 24 hours and then sectioned buccolingually. The sections were analyzed for leakage under a stereomicroscope. Data was analyzed by Kruskal-Wallis and Mann-Whitney tests at a significance level of P 0.05, except for groups 2 and 4 (P = 0.002 and groups 3 and 4 (P = 0.033. Conclusion. Use of a flowable composite with bonding agent is a good alternative for sealing pits and fissures; however, further in vitro and in vivo studies are necessary.

Effect of enamel sealants on tooth bleaching and on the color stability of the result.

Science.gov (United States)

Corcodel, N; Hassel, A J; Sen, S; Saure, D; Rammelsberg, P; Lux, C J; Zingler, S

2017-04-01

The purpose of this in vitro study was to evaluate the effect of enamel sealants on bleaching of natural teeth by use of 40 % hydrogen peroxide in a dental surgery. The color stability of the results from bleaching was, furthermore, determined 10 months after the bleaching procedure. In a standardized setting, four sealants (Pro Seal ® , Light Bond™ Sealant, Protecto ® , and Clinpro™ XT Varnish) were applied to and removed from human teeth in accordance with the manufacturer's instructions. Natural teeth served as medium; half of the teeth were sealed and the others served as controls. Hydrogen peroxide gel (40 %; Opalescence Boost; Ultradent Products, South Jordan, UT, USA) was used as bleaching agent. Color measurement was performed with a spectroradiometer (Photoresearch PR670) before the bleaching process (T1) and 24 h (T2) and 10 months (T3) after bleaching. The spectroradiometer results were expressed by use of the Commission Internationale de l'Éclairage (CIE) L*a*b* color notation. The L*, a*, and b* values of the sealed and the unsealed surfaces were not significantly different at any time during the study (p > 0.05), irrespective of the sealant used. Ten months after the bleaching process, mean L*, a*, and b* values were lower than at 1-day post-bleaching; the mean value of ΔE between 1-day post-bleaching and 10 months post-bleaching was 2.46 (±3.1). The results of the study suggest that the effectiveness of professional tooth whitening is not appreciably affected by the application of the four sealants tested.

Long-Standing Motor and Sensory Recovery following Acute Fibrin Sealant Based Neonatal Sciatic Nerve Repair

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Natalia Perussi Biscola

2016-01-01

Full Text Available Brachial plexus lesion results in loss of motor and sensory function, being more harmful in the neonate. Therefore, this study evaluated neuroprotection and regeneration after neonatal peripheral nerve coaptation with fibrin sealant. Thus, P2 neonatal Lewis rats were divided into three groups: AX: sciatic nerve axotomy (SNA without treatment; AX+FS: SNA followed by end-to-end coaptation with fibrin sealant derived from snake venom; AX+CFS: SNA followed by end-to-end coaptation with commercial fibrin sealant. Results were analyzed 4, 8, and 12 weeks after lesion. Astrogliosis, microglial reaction, and synapse preservation were evaluated by immunohistochemistry. Neuronal survival, axonal regeneration, and ultrastructural changes at ventral spinal cord were also investigated. Sensory-motor recovery was behaviorally studied. Coaptation preserved synaptic covering on lesioned motoneurons and led to neuronal survival. Reactive gliosis and microglial reaction decreased in the same groups (AX+FS, AX+CFS at 4 weeks. Regarding axonal regeneration, coaptation allowed recovery of greater number of myelinated fibers, with improved morphometric parameters. Preservation of inhibitory synaptic terminals was accompanied by significant improvement in the motor as well as in the nociceptive recovery. Overall, the present data suggest that acute repair of neonatal peripheral nerves with fibrin sealant results in neuroprotection and regeneration of motor and sensory axons.

In vitro study of Streptococcus mutans adhesion on composite resin coated with three surface sealants

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Da Hye Kim

2017-02-01

Full Text Available Objectives Although the coating of surface sealants to dental composite resin may potentially reduce bacterial adhesion, there seems to be little information regarding this issue. This preliminary in vitro study investigated the adhesion of Streptococcus mutans (S. mutans on the dental composite resins coated with three commercial surface sealants. Materials and Methods Composite resin (Filtek Z250 discs (8 mm in diameter, 1 mm in thickness were fabricated in a mold covered with a Mylar strip (control. In group PoGo, the surfaces were polished with PoGo. In groups PS, OG, and FP, the surfaces polished with PoGo were coated with the corresponding surface sealants (PermaSeal, PS; OptiGuard, OG; Fortify Plus, FP. The surfaces of the materials and S. mutans cells were characterized by various methods. S. mutans adhesion to the surfaces was quantitatively evaluated using flow cytometry (n = 9. Results Group OG achieved the lowest water contact angle among all groups tested (p 0.05 or significantly lower (group OG, p < 0.001 bacterial adhesion when compared with the control group. Conclusions The application of the surface sealants significantly reduced S. mutans adhesion to the composite resin polished with the PoGo.

Effect of occlusal calculus utilized as a potential "biological sealant" in special needs patients with gastric feeding tubes: a qualitative in vitro contrast to pit and fissure sealant restorations.

Science.gov (United States)

Owens, Barry M; Sharp, Harry K; Fourmy, Emily E; Phebus, Jeffrey G

2016-01-01

The aim of this case report and in vitro investigation was to evaluate the marginal microleakage of intact occlusal calculus of primary molars extracted from a special needs patient who received nutrition via a gastric feeding tube. An adolescent with a history of developmental disturbance presented for routine dental care in a hospital facility. Prophylaxis was performed, and 2 mandibular permanent molars were restored. Five primary molars were extracted due to mobility and delayed retention. Heavy deposits of intact calculus were present on the occlusal surfaces of the primary teeth. The extracted teeth were immersed in methylene blue dye solution, invested in acrylic resin, sectioned into blocks, and photographed at 20× and 40× magnification. Previously photographed calculus-free molars with pit and fissure sealants were reviewed and served as contrasting "restorations." The occlusal calculus on the primary teeth extracted from the patient absorbed the dye, while the comparison teeth containing pit and fissure sealants exhibited varying degrees of marginal dye penetration (microleakage). No marginal microleakage was noted in the calculus specimens, indicating that this substrate may serve as a "natural" occlusal surface sealant and that its removal from occlusal surfaces during routine oral prophylaxis may be unnecessary.

Fissure sealant materials: Wear resistance of flowable composite resins.

Science.gov (United States)

Asefi, Sohrab; Eskandarion, Solmaz; Hamidiaval, Shadi

2016-01-01

Background. Wear resistance of pit and fissure sealant materials can influence their retention. Wear characteristics of sealant materials may determine scheduling of check-up visits. The aim of this study was to compare wear resistance of two flowable composite resins with that of posterior composite resin materials. Methods. Thirty-five disk-shaped specimens were prepared in 5 groups, including two flowable composite resins (Estelite Flow Quick and Estelite Flow Quick High Flow), Filtek P90 and Filtek P60 and Tetric N-Ceram. The disk-shaped samples were prepared in 25-mm diameter by packing them into a two-piece aluminum mold and then light-cured. All the specimens were polished for 1minute using 600-grit sand paper. The samples were stored in distilled water at room temperature for 1 week and then worn by two-body abrasion test using "pin-on-disk" method (with distilled water under a 15-Nload at 0.05 m/s, for a distance of 100 meter with Steatite ceramic balls antagonists). A Profilometer was used for evaluating the surface wear. Data were analyzed with the one-way ANOVA. Results. Estelite Flow Quick exhibited 2708.9 ± 578.1 μm(2) and Estelite Flow Quick High Flow exhibited 3206 ± 2445.1 μm(2)of wear but there were no significant differences between the groups. They demonstrated similar wear properties. Conclusion. Estelite flowable composite resins have wear resistance similar to nano- and micro-filled and micro-hybrid composite resins. Therefore, they can be recommended as pit and fissure sealant materials in the posterior region with appropriate mechanical characteristics.

Efficacy of fibrin-sealants in reducing biliary leakage following laparoscopic common bile duct exploration.

Science.gov (United States)

Parra-Membrives, Pablo; Martínez-Baena, Darío; Lorente-Herce, José Manuel; Martín-Balbuena, Ramón

2018-05-21

In spite of the acquired experience with laparoscopic common bile duct exploration (LCBDE) for choledocholithiasis management, there is still a risk of biliary leakage of 5% to 15% following choledochotomy closure. We evaluate the usefulness of fibrin-collagen sealants to reduce the incidence of biliary fistula after laparoscopic choledochorrhaphy. We report a retrospective analysis of 96 patients undergoing LCBDE from March 2009 to March 2017, whose closure of the bile duct was completed by antegrade stenting and choledochorraphy or by performing a primary suture. The study population was divided into two groups according to whether they received a collagen-fibrin sealant covering the choledochorrhaphy or not, analyzing the incidence of postoperative biliary fistula in each group. Thirty-nine patients (41%) received a fibrin-collagen sponge while the bile duct closure was not covered in the remaining 57 patients (59%). The incidence of biliary fistula was 7.7% (3 patients) in the first group and 14% (8 patients) in the second group (P=.338). In patients who underwent primary choledochorraphy, the fibrin-collagen sealant reduced the incidence of biliary leakage significantly (4.5% vs. 33%, P=.020), which was a protective factor with an odds ratio of 10.5. Fibrin-collagen sealants may decrease the incidence of biliary fistula in patients who have undergone primary bile duct closure following LCBDE. Copyright © 2018 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

Effect of sealant agents on the color stability and surface roughness of nanohybrid composite resins.

Science.gov (United States)

Dede, Doğu Ömür; Şahin, Onur; Koroglu, Aysegül; Yilmaz, Burak

2016-07-01

The effect of sealant agents on the surface roughness and color stability of nanohybrid composite resins is unknown. The purpose of this in vitro study was to evaluate the effect of sealant agents on the surface roughness and color stability of 4 nanohybrid composite resin materials. Forty disks (10×2 mm) were fabricated for each nanohybrid composite resin material (Z-550, Tetric EvoCeram, Clearfill Majesty, Ice) (N=160) and divided into 4 surface treatment groups: 1 conventional polishing (control) and 3 different sealant agent (Palaseal, Optiglaze, BisCover) coupling groups (n=10). The specimens were thermocycled, and surface roughness (Ra) values were obtained with a profilometer. Scanning electron microscope images were also recorded. CIELab color parameters of each specimen were measured with a spectrophotometer before and after 7 days of storage in a coffee solution. Color differences were calculated by the CIEDE 2000 (ΔE00) formula. The data were statistically analyzed by 2-way ANOVA and by the Tukey HSD test (α=.05). The surface treatment technique significantly affected the Ra values of the composite resins tested (Pcomposite resin material was also significant for ΔE00 values (Pcomposite resin groups, significant decreases in Ra were observed only for the Palaseal agent coupled composite resin groups (except Ice) compared with the control groups (Pcomposite resin group, except for BisCover applied Clearfill Majesty (Pcomposite resin groups, significant differences were observed between the color change seen with BisCover and other sealants for Clearfill Majesty composite resin (Pcomposite resins except for Ice produced smoother surfaces. All surface sealant agents provided less discoloration of nanohybrid composite resins after coffee staining compared with conventional polishing except for BisCover applied Clearfill Majesty composite resin. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All

Clinical Evaluation of an Adhesive Sealant for Controlling Dental Caries in Naval Personnel: One-Year Results

Science.gov (United States)

1974-08-20

safeguards were employed in that a voltage monitoring strip chart recorder was employed during sealant placement to ensure continuous delivery of...adequate voltage to the ultraviolet light source (Nuva- Lite)* used for sealant polymerization. Also, a new air compressor** with suitable...ment effect in young Naval personnel. 2. The very low occlusal attack rate for untreated control teeth 3. Dirks, O. B., Houwink, B. and Kwant , G. W

[Ketoconazole and clindamycin efficacy vs oral clindamycin in premature membranes rupture prevention].

Science.gov (United States)

Castillo Huerta, Eugenio; Garibay Valencia, Miguel; Mirabent-González, Felio

2008-07-01

Vulvovaginitis is one of the main causes of premature membrane rupture. To evaluate effectiveness of a combination of ketoconazole (400 mg) and clindamycin (100 mg) in vaginal tablets, compared with clindamicyn alone (600 mg/daily) orally, for six days, to prevent premature membrane rupture in patients with vulvovaginitis. Longitudinal, prospective, comparative, randomized, double-blind, double-dummy study in patients older than 18 years, during them third trimester of normoevolutive pregnancy with symptomatic vulvovaginitis. Patients were monitored as out patient. Genital secretion culture and fresh studies were made. Signs and symptoms were evaluated in regular intervals: 4, 7 and 11 days. Pregnancy control was performed every three weeks, until childbirth or premature membrane rupture. 105 patients were included: 53 in the group of ketoconazole and clindamicyn (1), and 52 in the group of clindamycin alone (2). Symptoms were similar in both groups of treatment, without statistically significant differences. A case of group 2 has premature membrane rupture (p = 0.495). C. albicans was cultured in 35% of group 2 and in 11% of group 2. No adverse events with treatments were reported. The combination of ketoconazole and cindamycin was effective to prevent premature membrane rupture in patients with vulvovaginitis.

Frequency of remnants of sealants left behind in pits and fissures of occlusal surfaces after 2 and 3 years.

NARCIS (Netherlands)

Hu, X.; Zhang, W.; Fan, M.; Mulder, J.; Frencken, J.E.F.M.

2017-01-01

OBJECTIVES: The null-hypothesis tested was that there was no difference in the frequency of remnants of high-viscosity glass-ionomer sealants left behind in pits and fissures of occlusal surfaces of first permanent molars and that of resin composite and glass-carbomer sealants. MATERIALS AND

Knowledge and practices of caries prevention among Taiwanese dentists attending a national conference

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Tzu-Hsien Lin

2010-12-01

Conclusions: A portion of Taiwanese dentists seemed to have limited up-to-date information about certain topics related to caries prevention. The frequency of treatments for caries prevention, such as topical fluoride and sealants, did not match the perceived effectiveness of these treatments by participants.

A clinical trial to evaluate the retention of a silver cermet-ionomer cement used as a fissure sealant.

Science.gov (United States)

Mills, R W; Ball, I A

1993-01-01

A randomized clinical trial was under-taken to compare the retention of a silver cermet-ionomer cement, Ketac Silver, with a conventional, autopolymerizing BIS-GMA resin sealant, Delton, using matched pairs of fissure sites within each subject's mouth. One hundred twenty matched contralateral pairs of fissure sites in first and second permanent molars of 53 school children were sealed with the two materials. The choice of site and material was selected at random. The ages of the children ranged from five to 16 years; first permanent molars were sealed in the five- to 10-year age group, and second permanent molars in the 11- to 16-year age group. Sealants were assessed as present, partly present, or absent at 6, 12, and 24 months. The number of pairs of sites available for reassessment declined from 102 at six months to 59 at 24 months as patients were lost to the study. Retention rates were higher for the Ketac Silver sealants at all three inspection intervals (P cermet cement was better retained than conventional resin sealants in younger children.

Chylothorax after mediastinal ganglioneuroma resection treated with fibrin sealant patch: a case report

Science.gov (United States)

Chiarelli, Marco; Achilli, Pietro; Guttadauro, Angelo; Vertemati, Giuseppe; Terragni, Sabina; De Simone, Matilde

2017-01-01

Chylothorax is a severe condition resulting from the accumulation of chyle into the pleural space. We report the treatment of postoperative chylothorax after resection of mediastinal ganglioneuroma in a 17-year-old boy. Since conservative measures were not effective, we performed direct ligation of lymphatic vessels and pleurodesis. At subsequent surgical re-exploration for persisting chylothorax, accurate inspection of pleural cavity revealed residual chyle leakage. Fibrin sealant patches (TachoSil®) were placed over the source of leak with complete resolution of chylous effusion. To our knowledge, this is the first report of postoperative chylothorax successfully treated by the use of a fibrin sealant patch. PMID:29221335

Transcutaneous Drainage of Gel-Like Substance after Application of Hydrogel Dural Sealant: Report of Two Cases

OpenAIRE

Siman, Homayoun; Techy, Fernando

2015-01-01

Study Design?Case report. Objective?Incidental durotomy (IDT) is a common complication of spinal surgery. The use of collagen matrix graft along with hydrogel dural sealant is a common method of IDT repair. With this method, there have been several reported cases of detrimental dural sealant expansion in the literature. One case study reported an expansion rate greater than 300%; many report neurologic damage. This article reports the clinical course of two patients who developed postoperativ...

Effect of Acidulated Phosphate Fluoride (APF on the Mcroleakage of Composite Flow and Fssure Sealant Restorations

Directory of Open Access Journals (Sweden)

Arash Poorsattar Bejeh Mir

2012-09-01

Full Text Available Background and Aims: A large number of investigations have revealed that physical and chemical alterations and weight loss could occur in composite materials exposed to acidic phosphate fluoride (APF gel. The purpose of this study was to assess the microleakage of a fissure sealant and a flow composite exposed to acidulated phosphate fluoride (APF gel. Materials and Methods: In this in vitro study, 60 intact human extracted premolar teeth were used. After preparing the occlusal groove, the teeth were divided into two groups (n=30. Teeth were filled with either Helioseal fissure sealant (Vivadent, Germany or Tetric flow composite (Vivadent, Germany. After that, each group was divided into two subgroups (n=15: 1.23% APF gel (Sultan, U.S.A was applied in the case subgroups, while control subgroups were preserved in normal saline solution. All of teeth were covered with 2 layers of nail varnish except for the filling zone and 1mm around the border of filling. After submerging in 0.5% fushin solution, specimens were sectioned bucco-lingually. Then dye penetration through the filling and fissure sealant was assessed by means of a stereo-microscope. The depth of dye penetration was scored. The data were analyzed using One-way ANOVA and Levene test. Results: The mean values of dye penetration were 1.26±1.09, 1.4±1.05, 1.2±1.37, and 1.4±1.35 for fissure sealant+gel, composite+gel, composite+normal saline, and normal saline groups, respectively. No significant difference was found in inter-groups (P=0.96. Conclusion: Considering the result of the present research, APF gel had no significant effect on the microleakage of Tetric flow composite filling and Helioseal fissure sealant and thus, it can be applied for routine usage.

Radon penetration of concrete slab cracks, joints, pipe penetrations, and sealants

NARCIS (Netherlands)

Nielson, KK; Rogers, VC; Holt, RB; Pugh, TD; Grondzik, WA; deMeijer, RJ

1997-01-01

Radon movement through 12 test slabs with different cracks, pipe penetrations, cold joints, masonry blocks, sealants, and tensile stresses characterized the importance of these anomalous structural domains, Diffusive and advective radon transport were measured with steady-state air pressure

Usefulness of hemostatic sealants for minimizing ovarian damage during laparoscopic cystectomy for endometriosis.

Science.gov (United States)

Choi, Chahien; Kim, Woo Young; Lee, Dong Hee; Lee, San Hui

2018-03-01

We aimed to evaluate the impact of topical hemostatic sealants and bipolar coagulation during laparoscopic ovarian endometriotic cyst resection on ovarian reserve by comparing the rates of decrease in anti-Müllerian hormone (AMH). A randomized prospective data collection was made on women aged 19-45 years who planned to have laparoscopic ovarian cystectomy at one of two institutions (n = 80), Kangbuk Samsung Hospital, Seoul, Korea or National Health Insurance Service Ilsan Hospital, Goyang, Korea, from January 2014 to April 2016. Patients were randomly divided into two groups treated with either a topical hemostatic sealant or bipolar coagulation for hemostasis. The hemostatic group was randomized to the FloSeal or TachoSil subgroups. Preoperative and 3-month postoperative AMH levels were checked and the rates of decrease of AMH were compared. All patients enrolled were treated with dienogest (Visanne) for 6-12 months. None were lost to follow-up at postoperative 3 months, but about one-third of the patients had been lost to follow-up by 6-12 months. AMH was significantly decreased in both groups 3 months postoperatively; however, the rate of decrease in the bipolar coagulation group was greater than that in the hemostatic sealant group, 41.9% (interquartile range [IQR], 22.29-65.24) versus 18.1% (IQR, 10.94-29.90), P = 0.007. Between the two hemostatic subgroups, there was no significant difference in AMH decrease rate, 14.95% (IQR, 11.34-21.21) versus 18.1% (IQR 9.76-40.70), P = 0.204. Hemostatic sealants may be an alternative to bipolar coagulation for preservation of ovarian reserve after laparoscopic ovarian cystectomy for endometriosis. © 2017 Japan Society of Obstetrics and Gynecology.

Aquatic biofouling prevention by electrically charged nanocomposite polymer thin film membranes.

Science.gov (United States)

de Lannoy, Charles-François; Jassby, David; Gloe, Katie; Gordon, Alexander D; Wiesner, Mark R

2013-03-19

Electrically conductive polymer-nanocomposite (ECPNC) tight nanofiltration (NF) thin film membranes were demonstrated to have biofilm-preventing capabilities under extreme bacteria and organic material loadings. A simple route to the creation and application of these polyamide-carbon nanotube thin films is also reported. These thin films were characterized with SEM and TEM as well as FTIR to demonstrate that the carbon nanotubes are embedded within the polyamide and form ester bonds with trimesoyl chloride, one of the monomers of polyamide. These polymer nanocomposite thin film materials boast high electrical conductivity (∼400 S/m), good NaCl rejection (>95%), and high water permeability. To demonstrate these membranes' biofouling capabilities, we designed a cross-flow water filtration vessel with insulated electrical leads connecting the ECPNC membranes to an arbitrary waveform generator. In all experiments, conducted in highly bacterially contaminated LB media, flux tests were run until fluxes decreased by 45 ± 3% over initial flux. Biofilm-induced, nonreversible flux decline was observed in all control experiments and a cross-flow rinse with the feed solution failed to induce flux recovery. In contrast, flux decrease for the ECPNC membranes with an electric potential applied to their surface was only caused by deposition of bacteria rather than bacterial attachment, and flux was fully recoverable following a short rinse with the feed solution and no added cleaning agents. The prevention of biofilm formation on the ECPNC membranes was a long-term effect, did not decrease with use, and was highly reproducible.

Social Marketing Risk-Framing Approaches for Dental Sealants in Rural American Indian Children.

Science.gov (United States)

Larsson, Laura S; Champine, Dorothy; Hoyt, Dee; Lin, Lillian; Salois, Emily; Silvas, Sharon; Tail, Terri Weasel; Williams, Matthew

2015-01-01

To compare three variants of a culturally relevant and theoretically based message to determine the most influential risk-framing approach for improving intention to place dental sealants for preschool children. A convenience sample of adult, American Indian participants (n = 89) attending a community health fair were assigned to view a gain-framed, loss-framed, or mix-framed dental sealant message. We compared participants' scores on a 46-item survey to determine the relative effect of the frame assignment on seven indices of behavior change. The mean difference in participants' stage-of-change scores (x = 1.17, n = 89, SD = 1.90) demonstrated a significant improvement for all groups after watching the dental sealant message t88  = 5.81, p mix-framed message resulted in the highest scores. The gain-framed message was the least influential on four constructs. This finding is in contrast to findings that gain-framed oral health messages are most influential (Gallagher & Updegraff, 2012; O'Keefe & Jensen, 2007). Community advisory board members determined to use the mix-framed approach in an oral health social marketing campaign with a rural, American Indian audience. © 2015 Wiley Periodicals, Inc.

Effect of artificial aging on the bond durability of fissure sealants.

Science.gov (United States)

Yun, Xiaofei; Li, Wei; Ling, Chen; Fok, Alex

2013-06-01

To evaluate the effect of artificial aging on the bond durability of fissure sealants in vitro. Twenty bovine incisors received 4 different sealant treatments and were divided into four groups: 1. Ultraseal XT plus (UX); 2. Enamel Loc (EL); 3. 35% phosphoric acid plus Enamel Loc (PEL); 4. Adper Prompt L-Pop plus Clinpro (PPC). Beam-shaped specimens were prepared and randomly divided into three subgroups. One subgroup underwent the microtensile bond strength (µTBS) test after 24-h storage in 37°C water. The other two subgroups were also subjected to the microtensile bond strength test after 5000 and 10,000 thermal cycles, respectively. Another twelve intact human third molars were sealed using 1 of 3 methods and were divided into 3 groups of 4 each: 1. Ultraseal XT plus; 2. Adper Prompt L-Pop plus Clinpro; and 3. Enamel Loc. Two specimens from each group were immersed in a 50% silver nitrate solution for 24 h, followed by exposure to fluorescent light for 8 h, before being scanned in a micro-CT (microcomputer tomography) machine. The other two were handled in the same way after undergoing 10,000 thermal cycles. The CT images obtained were evaluated. All samples from the EL group were broken during preparation, so no µTBS results were available. After 5000 thermal cycles, the bond strengths of the three other groups (UX, PEL, PPC) decreased significantly (p artificial aging. Micro-CT, a nondestructive analytical tool, may be used to evaluate the sealant/enamel interface effectively.

Knowledge, value, opinion and practice about usage of pit and fissure sealant among dental professionals in Chennai, Tamil Nadu, India.

Science.gov (United States)

Nagappan, N; Dhamodhar, M Dinesh; Nithin, M G; Kumar, E Senthil

2015-12-01

A study was aimed to assess the knowledge, value, opinion, and practice regarding the use of dental sealants among private dental practitioners in Chennai, Tamil Nadu, India. A self-administrated questionnaire were distributed to 192 private dental practitioners in Chennai, Tamil Nadu, India by using simple random sampling. A convenience sampling technique was employed. The questionnaire consisted of 28 items, which included information about knowledge, value, opinion, and practice regarding dental sealants. The questionnaire was obtained from the study by San Martin et al. 2013 and Kailash Asawa et al. 2014. Frequency distribution was tabulated. For frequency distribution strongly, strongly agree, and agree were combined as "agree" and strongly disagree and disagree were combined as "disagree." There were no changes in "neutral." Among the 196 study subjects 56.2% were males and 43.8% were females with their clinical experience of 52.1% for 15 years. The mean scores for knowledge, value, opinion, and practice were 41.8 ± 3.7, 18.7 ± 2.8, 18.1 ± 1.4, and 12.9 ± 2.3, respectively. The results suggest that dental practitioners had satisfactory knowledge about pit and fissure sealant and had neutral attitudes about sealants being effective. Dental practitioners adequately used the pit and fissure sealants but they did not follow the standardized procedures and specific guidelines.

Chemically bonded phosphate ceramic sealant formulations for oil field applications

Science.gov (United States)

Wagh, Arun S [Naperville, IL; Jeong, Seung-Young [Taejon, KR; McDaniel, Richard [Crest Hill, IL

2008-10-21

A sealant for an oil or geothermal well capable of setting within about 3 to about 6 hours at temperatures less than about 250.degree. F. for shallow wells less than about 10,000 feet and deep wells greater than about 10,000 feet having MgO present in the range of from about 9.9 to about 14.5%, KH.sub.2PO.sub.4 present in the range of from about 29.7 to about 27.2%, class C fly ash present in the range of from about 19.8 to about 36.3%, class F fly ash present in the range of from about 19.8 to about 0%, boric acid or borax present in the range of from about 0.39 to about 1.45%, and water present in the range of from about 20.3 to about 21.86% by weight of the sealant.A method of sealing wells is disclosed as are compositions for very high temperature wells is disclosed as is a composition for treating oil field wastes.

Internal Limiting Membrane Peeling to Prevent Post-vitrectomy Epiretinal Membrane Development in Retinal Detachment.

Science.gov (United States)

Akiyama, Kunihiko; Fujinami, Kaoru; Watanabe, Ken; Tsunoda, Kazushige; Noda, Toru

2016-11-01

To determine the efficacy of internal limiting membrane (ILM) peeling during vitrectomy for rhegmatogenous retinal detachment (RRD) regarding post-vitrectomy epiretinal membrane (ERM) development and visual outcomes. Retrospective, interventional, comparative case series. Setting: Institutional. One hundred and two consecutive eyes with RRD treated with vitrectomy and followed for at least 6 months. ILM was peeled without using dye such as indocyanine green (ICG). Observational Procedures: Patients were divided into 2 groups based on postoperative ERM development: Group 1, 81 eyes without ERM formation; Group 2, 21 eyes with ERM development. Patients also were divided into 2 subgroups: those with and without ILM peeling (58 and 44 eyes, respectively). Statistical analyses were performed between the 2 groups with/without ERM formation and between the 2 subgroups with/without ILM peeling for 5 preoperative factors including foveal involvement of the RRD, 4 intraoperative factors including ILM peeling, baseline best-corrected visual acuity (BCVA), and final BCVA. An association of ILM peeling with ERM prevention and the influence of ILM peeling on visual outcomes. ILM peeling was significantly (P peeling. ILM peeling without ICG staining during the initial vitrectomy for RRDs may prevent postoperative ERM formation with favorable visual outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

Fibrin sealants or cell saver eliminate the need for autologous blood donation in anemic patients undergoing primary total knee arthroplasty.

Science.gov (United States)

Bou Monsef, Jad; Buckup, Johannes; Waldstein, Wenzel; Cornell, Charles; Boettner, Friedrich

2014-01-01

Reducing allogeneic blood transfusions remains a challenge in total knee arthroplasty. Patients with preoperative anemia have a particularly high risk for perioperative blood transfusions. 176 anemic patients (Hb < 13.5 g/dl) undergoing total knee replacement were prospectively evaluated to compare the effect of a perioperative cell saver (26 patients), intraoperative fibrin sealants (5 ml Evicel, Johnson & Johnson Wound Management, Ethicon, Somerville, NJ) (45 patients), preoperative autologous blood donation (PABD) (21 patients), the combination of fibrin sealants and preoperative autologous blood donation (44) and no intervention (40 patients) on perioperative blood loss and transfusion requirements. All protocols resulted in significant reduction of allogeneic blood transfusions. Transfusion rates were similar with the use of PABD (19%), Evicel (18%), and cell saver (19%), all significantly lower than the control group (38 %, p < 0.05). Combining Evicel with PABD resulted in significantly higher wastage of autologous units (p < 0.05) with no significant reduction in allogeneic transfusion rate (14%). The use of fibrin sealant resulted in a significant reduction of blood loss compared to the PABD group (603 vs. 810 ml, p < 0.005) as well as the control group (603 vs. 822 ml, p < 0.005). While PABD proved to be the most cost-effective treatment option in anemic patients, fibrin sealants and cell saver show similar reduction in allogeneic transfusion rates compared to controls. The combination of fibrin sealants and PABD is not cost-effective and increases the number of wasted units.

A randomised trial of lung sealant versus medical therapy for advanced emphysema

NARCIS (Netherlands)

Come, Carolyn E.; Kramer, Mordechai R.; Dransfield, Mark T.; Abu-Hijleh, Muhanned; Berkowitz, David; Bezzi, Michela; Bhatt, Surya P.; Boyd, Michael B.; Cases, Enrique; Chen, Alexander C.; Cooper, Christopher B.; Flandes, Javier; Gildea, Thomas; Gotfried, Mark; Hogarth, D. Kyle; Kolandaivelu, Kumaran; Leeds, William; Liesching, Timothy; Marchetti, Nathaniel; Marquette, Charles; Mularski, Richard A.; Pinto-Plata, Victor M.; Pritchett, Michael A.; Rafeq, Samaan; Rubio, Edmundo R.; Slebos, Dirk-Jan; Stratakos, Grigoris; Sy, Alexander; Tsai, Larry W.; Wahidi, Momen; Walsh, John; Wells, J. Michael; Whitten, Patrick E.; Yusen, Roger; Zulueta, Javier J.; Criner, Gerard J.; Washko, George R.

Uncontrolled pilot studies demonstrated promising results of endoscopic lung volume reduction using emphysematous lung sealant (ELS) in patients with advanced, upper lobe predominant emphysema. We aimed to evaluate the safety and efficacy of ELS in a randomised controlled setting. Patients were

INVESTIGATION OF THE POTENTIAL ANTIMICROBIAL EFFICACY OF SEALANTS USED IN HVAC SYSTEMS

Science.gov (United States)

The paper gives results of an investigation of the potential antimicrobial efficacy of sealants used in heating, ventilation and air-conditioning systems. Recent experiments confirm field experience that duct cleaning alone may not provide adequate protection from regrowth of fu...

Fixation of osteochondral fractures in rabbit knees. A comparison of Kirschner wires, fibrin sealant, and polydioxanone pins.

Science.gov (United States)

Plaga, B R; Royster, R M; Donigian, A M; Wright, G B; Caskey, P M

1992-03-01

We compared fibrin sealant, polydioxanone (PDS) pins and Kirschner wires in the fixation of osteochondral fractures in rabbit knees. Standardised osteochondral fractures of the right medial femoral condyle were made in 56 adult New Zealand white rabbits. There were equal groups of control knees, and those which had Kirschner-wire, fibrin-sealant or PDS-pin fixation. No external immobilisation was used. One animal from each group was killed at two, three and four weeks. The remaining rabbits were killed at six weeks. A fracture which healed with less than 1 mm of displacement was considered a success. There was successful healing in 29% of the control group, in all of the Kirschner-wire group, in 50% of the fibrin-sealant group, and in 86% of the PDS-pin group. The use of PDS pins appears to be a reliable alternative to the use of metal in the fixation of osteochondral fractures in rabbits.

Design approach to sealant selection for the life of the well

NARCIS (Netherlands)

Bosma, M.; Ravi, K.; Driel, W.D. van; Schreppers, G.M.A.

1999-01-01

Recent experience in the field has demonstrated that the mechanical properties of the annular sealant are a critical factor in the success of a well. A demanding operational regime of the well such as High Pressure/High Temperature (HP/HT) and well interventions, e.g. pressure testing stimulation,

Evaluation of asbestos exposure within the automotive repair industry: a study involving removal of asbestos-containing body sealants and drive clutch replacement.

Science.gov (United States)

Blake, Charles L; Dotson, G Scott; Harbison, Raymond D

2008-12-01

Two independent assessments were performed of airborne asbestos concentrations generated during automotive repair work on vintage vehicles . The first involved removal of asbestos-containing seam sealant, and the second involved servicing of a drive clutch. Despite the relatively high concentrations (5.6-28%) of chrysotile fibers detected within bulk samples of seam sealant, the average asbestos concentration for personal breathing zone (PBZ) samples during seam sealant removal was 0.006 f/cc (fibers/cubic centimeter of air). Many other air samples contained asbestos at or below the analytical limit of detection (LOD). Pneumatic chiseling of the sealant material during removal resulted in 69% of area air samples containing asbestos. Use of this impact tool liberated more asbestos than hand scraping. Asbestos fibers were only detected in air samples collected during the installation of a replacement clutch. The highest asbestos corrected airborne fiber concentration observed during clutch installation was 0.0028 f/cc. This value is approximately 100 times lower than Occupational Safety and Health Administration's (OSHA) permissible exposure limit (PEL) of 0.1f/cc. The airborne asbestos concentrations observed during the servicing of vintage vehicles with asbestos-containing seam sealant and clutches are comparable to levels reported for repair work involving brake components and gaskets.

Clinical performance of a glass ionomer sealant protected with two different resin-based agents over a 2-year follow-up period.

Science.gov (United States)

Ulusoy, A T; Tunc, E S; Bayrak, Ş

2017-03-01

To evaluate the effects of two different resin coating materials on the clinical performance of a conventional glass ionomer sealant. Permanent first mandibular molars of 60 children aged 6-9 years were sealed with Fuji VII. In each child, G-Coat Plus coating agent was applied to molars on one side and Heliobond coating agent to molars on the opposite side of the mouth. Clinical evaluations were carried out at 1, 6, 12, 18 and 24 months after sealant and coating application. At 1, 6, 12, 18 and 24 months after sealant and coating application, total sealant retention rates were 88%, 40%, 19%, 15% and 9% for molars coated with G-Coat Plus, and 93%, 47%, 17%, 15% and 7% for those coated with Heliobond. The differences between the two coating agents were not statistically significant (p>0.05). No incidence of caries was observed in either group during the two-year evaluation period. Wilcoxon signed rank test was used to compare differences in retention rates and caries incidence by coating agent. Although retention rates of Fuji VII were relatively low and similar for both resin coating agents tested, dental caries were not observed in either group during the 24-month study period. In children with a high risk of caries and partially erupted molars, the use of a glass ionomer sealant with a resin-based coating agent should be encouraged.

Randomized clinical trial of fibrin sealant versus titanium tacks for mesh fixation in laparoscopic umbilical hernia repair

DEFF Research Database (Denmark)

Eriksen, J R; Bisgaard, T; Assaadzadeh, S

2011-01-01

The use of tacks for mesh fixation may induce pain after surgery for ventral hernia. The aim of this study was to compare postoperative pain after laparoscopic ventral hernia repair (LVHR) with conventional mesh fixation using titanium tacks versus fibrin sealant (FS).......The use of tacks for mesh fixation may induce pain after surgery for ventral hernia. The aim of this study was to compare postoperative pain after laparoscopic ventral hernia repair (LVHR) with conventional mesh fixation using titanium tacks versus fibrin sealant (FS)....

Dental sealants and restorations and urinary bisphenol A concentrations in children in the 2003-2004 National Health and Nutrition Examination Survey.

Science.gov (United States)

McKinney, Christy; Rue, Tessa; Sathyanarayana, Sheela; Martin, Michael; Seminario, Ana Lucia; DeRouen, Timothy

2014-07-01

Resin-based dental sealants and composites contain bisphenol A-glycidyl methacrylate, a bisphenol A (BPA) derivative. The authors hypothesized that a greater number of sealants or restorations would be associated with higher urinary BPA concentrations. The authors examined urinary BPA measurements (in nanograms per milliliter) and oral examination data for 1,001 children aged 6 to 19 years from data sets of the 2003-2004 National Health and Nutrition Examination Survey (NHANES). They categorized children according to number of occlusal sealants and number of restorations, with four categories in each of the two groups. They estimated associations by using unadjusted and adjusted tobit regression models. The lowest quartile of BPA concentrations ranged from 0.3 ng/mL to 1.9 ng/mL, whereas the highest quartile ranged from 7.3 ng/mL to 149 ng/mL. In adjusted analysis, children with seven to 16 sealants had geometric mean BPA concentrations 25 percent higher than those of children with no sealants (95 percent confidence interval [CI], -14 percent to 82 percent; P = .23). In adjusted analysis, children with seven to 42 restorations had geometric mean BPA concentrations 20 percent higher than those of children with no restorations (95 percent CI, -6 percent to 53 percent; P = .13). Neither of these adjusted estimates was statistically significant. Though the findings were in the direction hypothesized, the authors did not observe a statistically significant association between a greater number of sealants or restorations and higher urinary BPA concentrations. Additional studies are needed to determine the extent of oral and systemic exposure to BPA from resin-based dental restorative materials over time. Dentists should follow this issue carefully as it develops and as the body of evidence grows. There is insufficient evidence to change practice at this time.

[Pollution prevention and control of aqueous extract of astragali radix processed with ZrO2 inorganic ceramic membrane micro-filtration].

Science.gov (United States)

Pan, Lin-Men; Huang, Min-Yan; Guo, Li-Wei

2012-11-01

To study the measures for preventing and controlling the pollution of aqueous extract of Astragali Radix proceeded with inorganic ceramic membrane micro-filtration, in order to find effective measures for preventing and controlling the membrane pollution. The resistance distribution, polymer removal and changes in physical and chemical parameters of the zirconium oxide film of different pore diameters were determined to analyze the state or location of pollutants as well as the regularity of formation. Meanwhile, recoil and ultrasonic physical measures were adopted to strengthen the membrane process, in order to explore the methods for preventing and controlling the membrane pollution. When 0.2 microm of ZrO2 micro-filtrated aqueous extract of Astragali Radix, the rate of pollution was as high as 44.9%. The hole blocking resistance and the concentration polarization resistance were the main filtration resistances, while the surface deposit resistance decreased with the increase in the membrane's hold diameter; after micro-filtration, the liquid turbidity significantly reduced, with slight changes in both pH and viscosity. The 0.2 microm ZrO2 micro-filtration membrane performed better than the 0.05 microm pore size membrane in terms of conductivity. The 0. 2 microm and 0.05 microm pore diameter membranes showed better performance in the removal of pectin. The ultrasonic measure to strengthen membranes is more suitable to this system, with a flux rate up by 41.7%. The membrane optimization process adopts appropriate measures for preventing and controlling the membrane pollution, in order to reduce the membrane pollution, recover membrane performance and increase filtration efficiency.

Behavior of adhesion forces of silicone adhesive sealants and mastic butyl under the influence of ionizing radiation

International Nuclear Information System (INIS)

Costa, Wanderley da

2012-01-01

Adhesives are products that can keep materials together by bonds between the surfaces. Sealants are products that can keep filled a space between two surfaces, through a barrier that is configured as a 'bridge' between the two surfaces. The mastic is a product made of a mixture of substances with the primary butyl polymer, with the consistency of a mass not dried that can be used as a sealant. The polysiloxane, also known as silicone are the most important synthetic polymers with inorganic structure, and are matrices of silicone adhesive sealants. To demonstrate the behavior of the adhesive forces of these products under different conditions, we used five different techniques. These products were subjected to two different conditions to verify the behavior of adhesion, one at the environmental condition and another under the ionizing radiation. The results showed not only differences between products (silicone and mastic), but also that the adhesive forces have different behaviors under the conditions which the samples were subjected. With this was reached the goal of this study that aspired show the differences between the mastic and silicone, this last one is often considered - erroneously - the same as mastic. Thus it was proven that: 1. silicone can be regarded as an adhesive and a sealant at ambient conditions, 2. mastic improves substantially adhesion in an environment of ionizing radiation and this property can be an excellent alternative to the adhesive market. (author)

Use of rhamnolipid biosurfactant for membrane biofouling prevention and cleaning.

Science.gov (United States)

Kim, Lan Hee; Jung, Yongmoon; Kim, Sung-Jo; Kim, Chang-Min; Yu, Hye-Weon; Park, Hee-Deung; Kim, In S

2015-01-01

Rhamnolipids were evaluated as biofouling reducing agents in this study. The permeability of the bacterial outer membrane was increased by rhamnolipids while the growth rate of Pseudomonas aeruginosa was not affected. The surface hydrophobicity was increased through the release of lipopolysaccharides and extracellular polymeric substances from the outer cell membrane. Rhamnolipids were evaluated as agents for the prevention and cleaning of biofilms. A high degree of biofilm detachment was observed when the rhamnolipids were used as a cleaning agent. In addition, effective biofilm reduction occurred when rhamnolipids were applied to various species of Gram-negative bacteria isolated from seawater samples. Biofilm reduction using rhamnolipids was comparable to commercially available surfactants. In addition, 20% of the water flux was increased after rhamnolipid treatment (300 μg ml(-1), 6 h exposure time) in a dead-end filtration system. Rhamnolipids appear to have promise as biological agents for reducing membrane biofouling.

A 12-month clinical evaluation of pit-and-fissure sealants placed with and without etch-and-rinse and self-etch adhesive systems in newly-erupted teeth

Directory of Open Access Journals (Sweden)

Maryam Karami Nogourani

2012-06-01

Full Text Available OBJECTIVES: The objective of this one-year clinical study was to investigate the effect of two adhesive systems (Adper Single Bond, a two-step etch-and-rinse and Clearfil SE Bond, a two-step self-etch system on pit-and-fissure sealant retention in newly-erupted teeth. This study compared the success of the sealants in mesial and distopalatal grooves with and without these two adhesive systems. MATERIAL AND METHODS: In a clinical trial, 35 children aged 6-8 years undergoing sealant placement were recruited. This one-year clinical study scored 70 mesial and 70 distopalatal sealants of newly-erupted permanent maxillary first molar, with a split-mouth design. All children received sealant alone in one permanent maxillary molar tooth. Children were randomized into two groups. One group received Self-etch (Se bond plus sealant and the other group received Single Bond plus sealant in another permanent maxillary molar tooth. Clinical evaluation at 3, 6 and 12 months was performed and the retention was studied in terms of the success and failure. RESULTS: The success rate of sealant in the distopalatal groove, using SeB at 3, 6 and 12 months was 93.3% (95% CI: 68.0, 99.8, 73.3% (95% CI: 44.9, 92.2 and 66.7% (95% CI: 38.4, 88.2, respectively. It was greater than that of the distopalatal groove in SB group with a success rate of 62.5% (95% CI: 35.4, 84.8, 31.3% (95% CI: 11.8, 58.7 and 31.3% (95% CI: 11.8, 58.7, at the three evaluation periods. The success rate of sealant in the mesial groove using SeB was 86.6% (95% CI: 59.5, 98.3, 53.3% (95% CI: 26.6, 78.7 and 53.3% (95% CI: 26.6, 78.7, while this was 100% (95% CI: 79.4, 100.0, 81.3% (95% CI: 54.4, 96.0 and 81.3% (95% CI: 54.4, 96.0 using SB, at 3, 6 and 12-month evaluation periods. CONCLUSIONS: These results support the use of these two bonding agents in pit-and-fissure sealants under both isolated and contaminated conditions. Further, Se bond seemed to be less sensitive to moisture contamination.

Combination of heterologous fibrin sealant and bioengineered human embryonic stem cells to improve regeneration following autogenous sciatic nerve grafting repair.

Science.gov (United States)

Mozafari, Roghayeh; Kyrylenko, Sergiy; Castro, Mateus Vidigal; Ferreira, Rui Seabra; Barraviera, Benedito; Oliveira, Alexandre Leite Rodrigues

2018-01-01

Peripheral nerve injury is a worldwide clinical problem, and the preferred surgical method for treating it is the end-to-end neurorrhaphy. When it is not possible due to a large nerve gap, autologous nerve grafting is used. However, these surgical techniques result in nerve regeneration at highly variable degrees. It is thus very important to seek complementary techniques to improve motor and sensory recovery. One promising approach could be cell therapy. Transplantation therapy with human embryonic stem cells (hESCs) is appealing because these cells are pluripotent and can differentiate into specialized cell types and have self-renewal ability. Therefore, the main objective of this study was to find conditions under which functional recovery is improved after sciatic nerve neurorrhaphy. We assumed that hESC, either alone or in combination with heterologous fibrin sealant scaffold, could be used to support regeneration in a mouse model of sciatic nerve injury and repair via autografting with end-to-end neurorrhaphy. Five millimeters of the sciatic nerve of C57BL/6 J mice were transected off and rotated 180 degrees to simulate an injury, and then stumps were sutured. Next, we applied heterologous fibrin sealant and/or human embryonic stem cells genetically altered to overexpress fibroblast growth factor 2 (FGF2) at the site of the injury. The study was designed to include six experimental groups comprising neurorrhaphy (N), neurorrhaphy + heterologous fibrin sealant (N + F), neurorrhaphy + heterologous fibrin sealant + doxycycline (N + F + D), neurorrhaphy + heterologous fibrin sealant + wild-type hESC (N + F + W), neurorrhaphy + heterologous fibrin sealant + hESC off (N + F + T), and neurorrhaphy + heterologous fibrin sealant + hESC on via doxycycline (N + F + D + T). We evaluated the recovery rate using Catwalk and von Frey functional recovery tests, as well as immunohistochemistry analysis. The experiments indicated that

Evidence of Effectiveness of Current Therapies to Prevent and Treat Early Childhood Caries

DEFF Research Database (Denmark)

Twetman, Svante; Dhar, Vineet

2015-01-01

PURPOSE: The purpose of this paper was to systematically review the quality of evidence related to self-applied and professionally applied fluorides, antimicrobial agents, fissure sealants, temporary restorations, and restorative care for the prevention and management of early childhood caries (E...

THE EFFECT OF BONDING AND SURFACE SEALANT APPLICATION ON POSTOPERATIVE SENSITIVITY FROM POSTERIOR COMPOSITES

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Neslihan TEKÇE

2015-10-01

Full Text Available Purpose: The purpose of the study was to evaluate the postoperative sensitivity of posterior Class I composite restoration at short-term, restorated with two different all-in-one self-etch adhesives with or without surface sealant application. Materials and Methods: 44 restorations were inserted in 11 patients who required Class I restorations in their molars. Each patient received 4 restorations, thus four groups were formed; (1 G-Aenial Bond (GC, Japan; (2 Clearfil S3 Bond (Kuraray, Japan; (3 G-Aenial Bond+Fortify Plus (Bisco, USA, (4 Clearfil S3 Bond+Fortify Plus. Sensitivity was evaluated at 24h, 7, 15, and 30 days using cold air, ice, and pressure stimuli using a visual analog scale. Comparisons of continuous variables between the sensitivity evaluations were performed using the Friedman’s One-Way Analysis of Variance with repeated measures test (p0.05. The use of Clearfil S3 Bond resulted in almost the same level of postoperative sensitivity as did the use of G-Aenial Bond. The highest sensitivity scores were observed for the surface sealant applied teeth without any statistical significance (p>0.05. Conclusions: Self etch adhesives displayed postoperative sensitivity. The sensitivity scores slightly decreased at the end of 30 days (p>0.05. Surface sealant application did not result in a decrease in sensitivity scores for either dentin adhesives.

The Use of Pit and Fissure Sealants—A Literature Review

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Reem Naaman

2017-12-01

Full Text Available This paper reviews the literature and discusses the latest updates on the use of pit and fissure sealants. It demonstrates the effectiveness of pit and fissure sealants in preventing caries and the management of early carious lesions. It compares the use of different sealant materials and their indications. It describes the application technique for sealants. It also reviews the cost-effectiveness of sealants as a preventive strategy. From this review and after the discussion of recently published studies on pit and fissure sealants, it is evident that sealants are effective in caries prevention and in preventing the progression of incipient lesions. It is therefore recommended that pit and fissure sealant be applied to high-caries-risk children for optimum cost-effectiveness. It is a highly sensitive technique that needs optimum isolation, cleaning of the tooth surface, etching, and the application of a thin bonding layer for maximum benefit. Recall and repair, when needed, are important to maximize the effectiveness of such sealant use.

The Use of Pit and Fissure Sealants—A Literature Review

Science.gov (United States)

Naaman, Reem; El-Housseiny, Azza A.; Alamoudi, Najlaa

2017-01-01

This paper reviews the literature and discusses the latest updates on the use of pit and fissure sealants. It demonstrates the effectiveness of pit and fissure sealants in preventing caries and the management of early carious lesions. It compares the use of different sealant materials and their indications. It describes the application technique for sealants. It also reviews the cost-effectiveness of sealants as a preventive strategy. From this review and after the discussion of recently published studies on pit and fissure sealants, it is evident that sealants are effective in caries prevention and in preventing the progression of incipient lesions. It is therefore recommended that pit and fissure sealant be applied to high-caries-risk children for optimum cost-effectiveness. It is a highly sensitive technique that needs optimum isolation, cleaning of the tooth surface, etching, and the application of a thin bonding layer for maximum benefit. Recall and repair, when needed, are important to maximize the effectiveness of such sealant use. PMID:29563440

Color and opacity of composites protected with surface sealants and submitted to artificial accelerated aging.

Science.gov (United States)

Aguilar, Fabiano Gamero; Roberti Garcia, Lucas da Fonseca; Cruvinel, Diogo Rodrigues; Sousa, Ana Beatriz Silva; de Carvalho Panzeri Pires-de-Souza, Fernanda

2012-01-01

To evaluate the color similarity, stability and opacity of composites (TPH, Charisma, and Concept, shade A2) protected with surface sealants (Fortify Plus and Biscover) and cyanoacrylate (Super Bonder). Forty specimens of each composite were made and separated into 4 groups (n=10) according to the surface protection: GI - without sealant; GII - cyanoacrylate; GIII - Fortify Plus; GIV - Biscover. Color and opacity readings were taken before and after Artificial Acelerated Aging (AAA) and the values obtained for color stability were submitted to statistical analysis by 2-way ANOVA and Bonferroni's test (P<.05). The values acquired for color similarity were submitted to 1-way ANOVA and Tukey's test (P<.05). The specimen sufaces were compared before and after AAA using Scanning Electronic Microscopy (SEM). Studied composites did not present the same values for the coordinates L*, a* and b * before AAA, indicating that there was no color similarity among them. All composites presented color alteration after AAA with clinically unacceptable values. Protected groups presented lower opacity variation after AAA, in comparison with the control goup. SEM evaluation demonstrated that AAA increased the surface irregularities in all of the studied groups. Surface sealants were not effective in maintaining composite color, but were able to maintain opacity.

Percutaneous BioOrganic Sealing of Duodenal Fistulas: Case Report and Review of Biological Sealants with Potential Use in Interventional Radiology

Energy Technology Data Exchange (ETDEWEB)

Wadhwa, Vibhor, E-mail: vwadhwa1@jhmi.edu [Johns Hopkins University School of Medicine, Division of Vascular & Interventional Radiology (United States); Leeper, William R., E-mail: rob.leeper@jhmi.edu [Johns Hopkins University School of Medicine, Department of Surgery (United States); Tamrazi, Anobel, E-mail: atamraz1@jhmi.edu [Johns Hopkins University School of Medicine, Division of Vascular & Interventional Radiology (United States)

2015-08-15

Biological sealants are being increasingly used in a variety of surgical specialties for their hemostatic and sealing capabilities. However, their use in interventional radiology has not been widely reported. The authors describe a case of duodenal perforation occurring after 15 years of gastric bypass surgery, in whom surgical diversion was unsuccessfully attempted and the leakage was successfully controlled using percutaneous administration of a combination of biological and organic sealants.

THE STATE AND PERSPECTIVE OF HERMETIZATION OF UNDERGROUND STRUCTURES WITH USE OF RUBBER SEALANTS

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V. I. Leshchenko

2010-03-01

Full Text Available The works on creation of effective rubber sealants for hermetic sealing of joints of underground structures from modular ferroconcrete and pig-iron, including tunnel elements for the underground, are carried out.

PAH concentrations in lake sediment decline following ban on coal-tar-based pavement sealants in Austin, Texas

Science.gov (United States)

Van Metre, Peter C.; Mahler, Barbara J.

2013-01-01

Recent studies have concluded that coal-tar-based pavement sealants are a major source of polycyclic aromatic hydrocarbons (PAHs) in urban settings in large parts of the United States. In 2006, Austin, TX, became the first jurisdiction in the U.S. to ban the use of coal-tar sealants. We evaluated the effect of Austin’s ban by analyzing PAHs in sediment cores and bottom-sediment samples collected in 1998, 2000, 2001, 2012, and 2014 from Lady Bird Lake, the principal receiving water body for Austin urban runoff. The sum concentration of the 16 EPA Priority Pollutant PAHs (∑PAH16) in dated core intervals and surficial bottom-sediment samples collected from sites in the lower lake declined about 44% from 1998–2005 to 2006–2014 (means of 7980 and 4500 μg kg–1, respectively), and by 2012–2014, the decline was about 58% (mean of 3320 μg kg–1). Concentrations of ∑PAH16 in bottom sediment from two of three mid-lake sites decreased by about 71 and 35% from 2001 to 2014. Concentrations at a third site increased by about 14% from 2001 to 2014. The decreases since 2006 reverse a 40-year (1959–1998) upward trend. Despite declines in PAH concentrations, PAH profiles and source-receptor modeling results indicate that coal-tar sealants remain the largest PAH source to the lake, implying that PAH concentrations likely will continue to decline as stocks of previously applied sealant gradually become depleted.

The effect of different enamel surface treatments on microleakage of fissure sealants

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Asli Topaloglu-Ak

2013-11-01

Full Text Available Objective. The aim of this study was to evaluate the effects of different techniques of surface treatment on the microleakage of fissure sealants in permanent molar teeth in vitro. Materials and methods. 96 extracted impacted human third molars were randomly divided into 8 surface treatment groups (n=12/group as 1. Er: YAG laser; (Fidelis II, Fotona, Ljubljana, Slovenia (125 mj, 20Hz. 2. Er: YAG laser + 37% H3PO4 (15s; 3. ER: AG laser + 37% H3PO4+Prime&Bond NT; 4. Er: YAG laser + G Bond; 5. Er: YAG laser + Prime&Bond NT; 6. 37% H3PO4; 7. 37% H3PO4 + Prime &Bond NT; 8. G Bond. Sealant material (Clinpro, 3M ESPE, Seefeld, Germany, was applied into the fissures and light-cured for 20s with LED (Bluephase C5, Ivoclar-Vivadent, Schaan, Liechtenstein. Specimens were subjected to thermocycling (1000×, 5-55°C, dwell time: 15s and immersed in 0.5% basic fuchsin solution for 24h at 37°C. The samples were sectioned and scored on a 3 point rating scale using a light microscope with a magnification of ×20. One-way analysis of variance was used to analyze data. Multiple comparisons were analyzed using Bonferroni test (p=0.05. Results. Er:YAG laser showed the highest microleakage scores whereas Er YAG laser + 37% H3PO4 showed the lowest. Although 37% H3PO4 group showed higher scores than Er:YAG laser + 37% H3PO4, the difference was not statistically significant. Conclusion. Etching fissures with phosphoric acid is sufficient prior to fissure sealant application.

Aluminosilicate-based sealants for SOFCs and other electrochemical applications - A brief review

Science.gov (United States)

Tulyaganov, Dilshat U.; Reddy, Allu Amarnath; Kharton, Vladislav V.; Ferreira, José M. F.

2013-11-01

Among different designs of solid oxide fuel cells (SOFCs), planar design is the most promising due to easier fabrication, improved performance and relatively high power density. In planar SOFCs and other solid-electrolyte devices, gas-tight seals must be formed along the edges of each cell and between the stack and gas manifolds. For a sealant to work effectively in high-temperature SOFC environment, equilibrium needs to be achieved amid its mechanical properties and flow behavior so that it does not only maintain its hermeticity at high temperature but is also able to reduce mechanical stresses generated in the seal during thermal cycling. The most common sealants based on glass or glass-ceramic materials have been shown to operate in fuel cells for more than 1000 h with no significant degradation. Analysis of the current literature sources demonstrated that from thermal and chemical stability points of view, silicate based glass systems are more suitable than borate and borosilicate glass systems. In this work, different glass-ceramic (GC) compositions based on alkaline- and alkaline-earth aluminosilicate-based glass systems are reviewed with a special emphasis on their thermal, chemical, mechanical, and electrical properties. Based on these considerations, glass composition design approaches are provided that aid in search of the best seal glasses satisfying the rigid functional requirements. Among all the glass systems studied, a pyroxene based CaO-MgO-SrO-BaO-La2O3-Al2O3-SiO2 seal GC compositions have been specifically discussed because those have achieved appropriate thermal and chemical properties along with high stability. Approaches for further developments and optimization of GC sealants are briefly discussed.

Effectiveness of Fibrin Sealant Patch in Reducing Drain Volume after Pelvic Lymph Node Dissection in Women with Gynecologic Malignancy

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Hwa Cheong Kim

2017-01-01

Full Text Available Background. The goal of this study was to evaluate the effectiveness of fibrin sealant in decreasing postoperative lymphatic drainage in women after pelvic lymphadenectomy and/or para-aortic lymphadenectomy during gynecologic cancer surgery. Methods. This study is a retrospective case-control study. Forty-five patients who underwent staging surgery were enrolled. Twenty-seven patients were in the fibrin sealant group (group A and 18 in the control group (group B. The two groups were compared for the total volume of drain, hospital stay, harvested lymph node, and incidence of asymptomatic lymphocele. Lymphocele formation was evaluated by computed tomography (CT on 3 months after surgery. Results. There were no significant differences in patient demographics between group A and B with respect to age, BMI, and harvested lymph nodes. Patients who received fibrin sealants had reduced total volume of drainage from postoperative days 2 to 5 compared to the control group (group A versus group B: 994.819±745.85 ml versus 1847.89±1241.41 ml; P=0.015. However no differences were observed in hospital stay (P=0.282, duration of drain (P=0.207, and incidence of asymptomatic lymphocele at 3 months (P=0.126. Conclusion. The results of this study indicate that the application of fibrin sealants after pelvic and/or para-aortic lymphadenectomy may reduce lymphatic drainage in gynecologic malignancy.

A review of the literature: the economic impact of preventive dental hygiene services.

Science.gov (United States)

Sharon, Stull C; Connolly, Irene M; Murphree, Kellie R

2005-01-01

The contributions of dental hygiene as a discipline of prevention, the inception of systemic fluoride in community water systems, the continual research conducted by the National Institute of Dental and Craniofacial Research (NIDCR), and the success of dental sealants have all contributed to the decrease in incidences of dental diseases. The prevalence of employer-based dental insurance must also be recognized as contributing to a substantial paradigm shift on the utilization of oral health preventive services. This review of the economic impact of oral health preventive services on the consumer and the private dental practice suggests that these services have had a significant impact. Dentistry's challenge remains to extend these considerable gains in oral health status to the 150 million U.S. citizens who do not have access to oral health care services identified in the 2000 Oral Health in America: A Report of the Surgeon General. Utilizing preventive, therapeutic, and educational aspects of dental hygiene services, reaching communities without fluoridation of the public water supply, and incorporating mass pediatric dental sealant programs analogous to immunization programs would improve the oral health status of underserved populations.

No difference in sexual dysfunction after transabdominal preperitoneal (TAPP) approach for inguinal hernia with fibrin sealant or tacks for mesh fixation

DEFF Research Database (Denmark)

Pommergaard, H C; Burcharth, J; Andresen, K

2017-01-01

BACKGROUND: Postoperative sexual dysfunction in relation to laparoscopic groin hernia surgery may be related to methods of mesh fixation. However, this has not been investigated earlier. Moreover, results regarding sexual dysfunction in females have not been reported systematically. The aim...... of this study was to compare fibrin sealant versus tacks for fixation of mesh regarding sexual dysfunction in males and females. METHODS: Using the Danish Hernia Database, patients operated laparoscopically for groin hernia with a transabdominal preperitoneal (TAPP) procedure with fibrin sealant or tacks...... for mesh fixation were sent a questionnaire regarding sexual dysfunction. Sexually active patients without recurrence were evaluated in this study. RESULTS: Pain during sexual activity was present in 115 of 1019 (11.3 %) males and 17 of 147 (11.6 %) females. There was no difference between fibrin sealant...

Effect of dry period length on the effect of an intramammary teat sealant on the risk of mastitis in cattle treated with antibiotics at drying off.

Science.gov (United States)

Laven, R A; Balcomb, C C; Tulley, W T; Lawrence, K E

2014-07-01

The aim of this study was to evaluate, under farm conditions, the use of a teat sealant in addition to whole herd dry cow antibiotic therapy on the risk of clinical mastitis in dairy cattle at pasture, and to evaluate the impact of dry period length on that risk and the impact of the teat sealant on that risk. Dairy cows in three herds which used routine whole herd antibiotic therapy were randomly assigned to receive either treatment with an internal teat sealant (n=322) or no additional treatment (n=313) at drying-off between March and May 2010. All clinical mastitis cases during the dry period and to the end of the subsequent lactation were recorded by farm staff; factors affecting risk of clinical mastitis were then analysed using a Cox proportional hazards model. Median duration of the dry period was 112 days with >25% of cows having a dry period >130 days. The incidence risk of mastitis during lactation for cows treated with teat sealant was 9.9 (95% CI=6.9-13.7) cases per 100 cows compared with 17.9 (95% CI=13.8-22.6) cases per 100 cows for cows treated with antibiotic alone. The addition of a teat sealant to dry cow antibiotic therapy decreased the risk of clinical mastitis only in the first 33 days after calving (Hazard risk 0.24 (95% CI=0.12-0.48)). Length of dry period did not significantly affect the risk of clinical mastitis, or the effect of adding teat sealant to dry cow antibiotic therapy on the risk of clinical mastitis. In these herds where, based on the mastitis history, whole herd antibiotic therapy had been recommended, the use of a teat sealant significantly reduced the risk of clinical mastitis. This effect was limited to the first 33 days after calving; subsequently there was no significant effect of treatment. There was no effect of dry period length on risk of clinical mastitis, nor any significant interaction with treatment. Combination therapy with teat sealant and antibiotic was effective under New Zealand conditions in herds using whole

Autologous fibrin sealant (Vivostat®) in the neurosurgical practice: Part I: Intracranial surgical procedure

Science.gov (United States)

Graziano, Francesca; Certo, Francesco; Basile, Luigi; Maugeri, Rosario; Grasso, Giovanni; Meccio, Flavia; Ganau, Mario; Iacopino, Domenico G.

2015-01-01

Background: Hemorrhages, cerebrospinal fluid (CSF) fistula and infections are the most challenging postoperative complications in Neurosurgery. In this study, we report our preliminary results using a fully autologous fibrin sealant agent, the Vivostat® system, in achieving hemostasis and CSF leakage repair during cranio-cerebral procedures. Methods: From January 2012 to March 2014, 77 patients were studied prospectively and data were collected and analyzed. Autologous fibrin sealant, taken from patient's blood, was prepared with the Vivostat® system and applied on the resection bed or above the dura mater to achieve hemostasis and dural sealing. The surgical technique, time to bleeding control and associated complications were recorded. Results: A total of 79 neurosurgical procedures have been performed on 77 patients. In the majority of cases (98%) the same autologous fibrin glue provided rapid hemostasis and dural sealing. No patient developed allergic reactions or systemic complications in association with its application. There were no cases of cerebral hematoma, swelling, infection, or epileptic seizures after surgery whether in the immediate or in late period follow-up. Conclusions: In this preliminary study, the easy and direct application of autologous fibrin sealant agent helped in controlling cerebral bleeding and in providing prompt and efficient dural sealing with resolution of CSF leaks. Although the use of autologous fibrin glue seems to be safe, easy, and effective, further investigations are strongly recommended to quantify real advantages and potential limitations. PMID:25984391

Application of rape pod sealants to reduce adverse environmental impacts.

Science.gov (United States)

Bauša, Laimis; Steponavičius, Dainius; Jotautienė, Eglė; Kemzūraitė, Aurelija; Zaleckas, Ernestas

2018-04-01

Rape (Brassica napus L.) is a major global oilseed crop characterized by its high potential as an alimentary oil and in biodiesel production. The two most popular pod sealants (PS) used to reduce rape pod shattering are products in the pinolene range (di-1-p-menthene) and latex polymer products. Reports on the effective preservation of seed yield by these products are fairly contradictory. With this in mind, an experimental PS (PS4) that contained the active agents acrylic and trisiloxane was developed. Comparative experimental trials of the developed PS4 and three other PS (PS1, PS2 and PS3) containing active agents that are generally used for sealant production were conducted. The studies showed that the static and dynamic surface tension of PS4 was the lowest at the same concentration (2.0 g kg -1 ), consequently demonstrating the lowest spray drift. The chemical substances from PS had not penetrated the rape seeds in any of the PSs. The results indicate that treatment with PS4 exerts a beneficial effect in reducing rape seed yield loss (68-104 kg ha -1 in 2014 and 194-305 kg ha -1 in 2015) compared to other investigated PS. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Collector sealants and breathing. Final Report, 25 September 1978-31 December 1979

Energy Technology Data Exchange (ETDEWEB)

Mendelsohn, M A; Luck, R M; Yeoman, F A; Navish, Jr, F W

1980-02-20

The objectives of this program were: (1) to investigate the pertinent properties of a variety of possible sealants for solar collectors and identify the most promising candidates, and (2) to study the effect of breathing in flat-plate, thermal solar collector units. The study involved two types of sealants, Class PS which includes preformed seals or gaskets and Class SC which includes sealing compounds or caulks. It was the intent of the study to obtain data regarding initial properties of candidate elastomers from manufacturers and from the technical literature and to use those sources to provide data pertaining to endurance of these materials under environmental service conditions. Where necessary, these data were augmented by experimental measurements. Environmental stresses evaluated by these measurements included elevated temperatures, moisture, ultraviolet light, ozone and oxygen, and fungus. The second major area of the work involved a study of the effects of materials used and design on the durability of solar collectors. Factors such as design, fabrication, materials of construction, seals and sealing techniques and absorber plate coatings were observed on actual field units removed from service. Such phenomena as leakage, corrosion and formation of deposits on glazing and absorber plate were noted. An evaluation of the properties of several desiccants was made in order to providemeans to mitigate the deleterious effects of water on collector life. Adsorbents for organic degradation products of sealants were also investigated in order to protect the glazing and absorber plate from deposited coatings. Since adsorbents and desiccants in general tend to take up both water and organic decomposition products, relative affinities of a number of these agents for water and for organic compounds were determined . Results are presented in detail.

Protocol for “Seal or Varnish?” (SoV trial: a randomised controlled trial to measure the relative cost and effectiveness of pit and fissure sealants and fluoride varnish in preventing dental decay

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Chestnutt Ivor Gordon

2012-11-01

Full Text Available Abstract Background Dental caries remains a significant public health problem, prevalence being linked to social and economic deprivation. Occlusal surfaces of first permanent molars are the most susceptible site in the developing permanent dentition. Cochrane reviews have shown pit and fissure sealants (PFS and fluoride varnish (FV to be effective over no intervention in preventing caries. However, the comparative cost and effectiveness of these treatments is uncertain. The primary aim of the trial described in this protocol is to compare the clinical effectiveness of PFS and FV in preventing dental caries in first permanent molars in 6-7 year-olds. Secondary aims include: establishing the costs and the relative cost-effectiveness of PFS and FV delivered in a community/school setting; examining the impact of PFS and FV on children and their parents/carers in terms of quality of life/treatment acceptability measures; and examining the implementation of treatment in a community setting. Methods/design The trial design comprises a randomised, assessor-blinded, two-arm, parallel group trial in 6–7 year old schoolchildren. Clinical procedures and assessments will be performed at 66 primary schools, in deprived areas in South Wales. Treatments will be delivered via a mobile dental clinic. In total, 920 children will be recruited (460 per trial arm. At baseline and annually for 36 months dental caries will be recorded using the International Caries Detection and Assessment System (ICDAS by trained and calibrated dentists. PFS and FV will be applied by trained dental hygienists. The FV will be applied at baseline, 6, 12, 18, 24 and 30 months. The PFS will be applied at baseline and re-examined at 6, 12, 18, 24, and 30 months, and will be re-applied if the existing sealant has become detached/is insufficient. The economic analysis will estimate the costs of providing the PFS versus FV. The process evaluation will assess implementation and

Wellbore Completion Systems Containment Breach Solution Experiments at a Large Scale Underground Research Laboratory : Sealant placement & scale-up from Lab to Field

Science.gov (United States)

Goodman, H.

2017-12-01

This investigation seeks to develop sealant technology that can restore containment to completed wells that suffer CO2 gas leakages currently untreatable using conventional technologies. Experimentation is performed at the Mont Terri Underground Research Laboratory (MT-URL) located in NW Switzerland. The laboratory affords investigators an intermediate-scale test site that bridges the gap between the laboratory bench and full field-scale conditions. Project focus is the development of CO2 leakage remediation capability using sealant technology. The experimental concept includes design and installation of a field scale completion package designed to mimic well systems heating-cooling conditions that may result in the development of micro-annuli detachments between the casing-cement-formation boundaries (Figure 1). Of particular interest is to test novel sealants that can be injected in to relatively narrow micro-annuli flow-paths of less than 120 microns aperture. Per a special report on CO2 storage submitted to the IPCC[1], active injection wells, along with inactive wells that have been abandoned, are identified as one of the most probable sources of leakage pathways for CO2 escape to the surface. Origins of pressure leakage common to injection well and completions architecture often occur due to tensile cracking from temperature cycles, micro-annulus by casing contraction (differential casing to cement sheath movement) and cement sheath channel development. This discussion summarizes the experiment capability and sealant testing results. The experiment concludes with overcoring of the entire mock-completion test site to assess sealant performance in 2018. [1] IPCC Special Report on Carbon Dioxide Capture and Storage (September 2005), section 5.7.2 Processes and pathways for release of CO2 from geological storage sites, page 244

Laparoendoscopic single-site myomectomy and the use of fibrin sealant (Tisseel

Directory of Open Access Journals (Sweden)

Angelito Magno

2015-11-01

ensured after the suturing. A fibrin sealant, Tisseel (Baxter Healthcare Corp., Deerfield, IL, is applied over the suture site as an adjunct to hemostasis and also to prevent adhesion. The fundamental advantage of LESS is less incision, as a result, improves cosmesis. LESS myomectomy has many technical difficulties, including reduced visualization, loss of triangulation, and instrument interference. Thus, the type, location and numbers of the myomas are critical to succeed LESS myomectomy. The Food and Drug Administration has approved fibrin sealant in 1998 as an adjunct to hemostasis and sealing. Besides, certain studies have reported its anti-adhesion property. Upon mixing of the two components in the lumens of Tisseel, the combinations of thrombin and fibrinogen transformed into fibrin, forming a rubber-like tissue that adheres to the wound surface.

40 CFR 63.6000 - How do I conduct tests and procedures for puncture sealant application affected sources?

Science.gov (United States)

2010-07-01

... Tire Manufacturing Testing and Initial Compliance Requirements for Puncture Sealant Application... balances to demonstrate compliance, if the storage of materials, exhaust, or the wastewater from more than...

Effectiveness of audiovisual distraction in behavior modification during dental caries assessment and sealant placement in children with autism spectrum disorder.

Science.gov (United States)

Fakhruddin, Kausar Sadia; El Batawi, Hisham Yehia

2017-01-01

The aim of this study was to evaluate the effectiveness of audiovisual (AV) distraction in behavior modification during dental caries assessment and sealant placement in children with autism spectrum disorder. This study was conducted on 28 children diagnosed with autism spectrum disorder, aged 6.5-9.8 years. Children underwent one introductory (desensitization) appointment and three treatment sessions. During the introductory session, children had the procedures explained to them, they watched a movie projected on a screen while oral screening and assessment of cooperation level were carried out. In treatment session I, oral examination, charting, and dental x-rays were undertaken, whereas the children watched movies with or without video eyewear. During treatment sessions II/III, dental prophylaxis was carried out on upper and lower jaws in addition to the application of dental sealants on the right upper and lower and the left upper and lower permanent molars, respectively, while the children were distracted by cartoon movies using video eyewear. Changes in pulse oximeter and heart rate were recorded every 5 min. Independent samples t -test was used to assess the significance of changes in pulse and O 2 saturation levels during each visit. International Caries Detection and Assessment System-code 2 was found to be the most prevalent ( n = 58; 52%). A significant difference ( P behavior in the subjects. Video eyewear distraction proved an effective tool in managing children with autism spectrum disorder during noninvasive preventive dental procedures.

Two-year survival of glass ionomer sealanTs placed as parT of ...

African Journals Online (AJOL)

2010-09-09

Sep 9, 2010 ... Two-year survival of glass ionomer sealanTs placed as parT of proximal aTraumaTic. resToraTive ... absTracT. Objective: To evaluate after two years, the survival rate of glass ionomer cement (gic) ... or symptoms of periodontal disease, and clinically the ..... saliva contamination on the bond of dentine resin-.

A Test Method for Monitoring Modulus Changes during Durability Tests on Building Joint Sealants

Science.gov (United States)

Christopher C. White; Donald L. Hunston; Kar Tean Tan; Gregory T. Schueneman

2012-01-01

The durability of building joint sealants is generally assessed using a descriptive methodology involving visual inspection of exposed specimens for defects. It is widely known that this methodology has inherent limitations, including that the results are qualitative. A new test method is proposed that provides more fundamental and quantitative information about...

Enamel pretreatment with Er:YAG laser: effects on the microleakage of fissure sealant in fluorosed teeth

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Mahtab Memarpour,

2014-08-01

Full Text Available Objectives The purpose of this in vitro study was to evaluate the microleakage and penetration of fissure sealant in permanent molar teeth with fluorosis after pretreatment of the occlusal surface. Materials and Methods A total of 120 third molars with mild dental fluorosis were randomly divided into 6 groups (n = 20. The tooth surfaces were sealed with an unfilled resin fissure sealant (FS material. The experimental groups included: 1 phosphoric acid etching (AE + FS (control; 2 AE + One-Step Plus (OS, Bisco + FS; 3 bur + AE + FS; 4 bur + AE + OS + FS; 5 Er:YAG laser + AE + FS; and 6 Er:YAG laser + AE + OS + FS. After thermocycling, the teeth were immersed in 0.5% fuchsin and sectioned. Proportions of mircoleakage (PM and unfilled area (PUA were measured by digital microscope. Results Overall, there were significant differences among all groups in the PM (p = 0.00. Group 3 showed the greatest PM, and was significantly different from groups 2 to 6 (p < 0.05. Group 6 showed the lowest PM. Pretreatment with Er:YAG with or without adhesive led to less PM than bur pretreatment. There were no significant differences among groups in PUA. Conclusions Conventional acid etching provided a similar degree of occlusal seal in teeth with fluorosis compared to those pretreated with a bur or Er:YAG laser. Pretreatment of pits and fissures with Er:YAG in teeth with fluorosis may be an alternative method before fissure sealant application.

A Systematic Approach to the Study of Accelerated weathering of Building Joint Sealants

Science.gov (United States)

Christopher C. White; Donald L. Hunston; Kar Tean Tan; James J. Filliben; Adam L. Pintar; Greg. Schueneman

2012-01-01

An accurate service life prediction model is needed for building joint sealants in order to greatly reduce the time to market of a new product and reduce the risk of introducing a poorly performing product into the marketplace. A stepping stone to the success of this effort is the precise control of environmental variables in a laboratory accelerated test apparatus in...

Stabilization of mitochondrial membrane potential prevents doxorubicin-induced cardiotoxicity in isolated rat heart

International Nuclear Information System (INIS)

Montaigne, David; Marechal, Xavier; Baccouch, Riadh; Modine, Thomas; Preau, Sebastien; Zannis, Konstantinos; Marchetti, Philippe; Lancel, Steve; Neviere, Remi

2010-01-01

The present study was undertaken to examine the effects of doxorubicin on left ventricular function and cellular energy state in intact isolated hearts, and, to test whether inhibition of mitochondrial membrane potential dissipation would prevent doxorubicin-induced mitochondrial and myocardial dysfunction. Myocardial contractile performance and mitochondrial respiration were evaluated by left ventricular tension and its first derivatives and cardiac fiber respirometry, respectively. NADH levels, mitochondrial membrane potential and glucose uptake were monitored non-invasively via epicardial imaging of the left ventricular wall of Langendorff-perfused rat hearts. Heart performance was reduced in a time-dependent manner in isolated rat hearts perfused with Krebs-Henseleit solution containing 1 μM doxorubicin. Compared with controls, doxorubicin induced acute myocardial dysfunction (dF/dt max of 105 ± 8 mN/s in control hearts vs. 49 ± 7 mN/s in doxorubicin-treated hearts; *p < 0.05). In cardiac fibers prepared from perfused hearts, doxorubicin induced depression of mitochondrial respiration (respiratory control ratio of 4.0 ± 0.2 in control hearts vs. 2.2 ± 0.2 in doxorubicin-treated hearts; *p < 0.05) and cytochrome c oxidase kinetic activity (24 ± 1 μM cytochrome c/min/mg in control hearts vs. 14 ± 3 μM cytochrome c/min/mg in doxorubicin-treated hearts; *p < 0.05). Acute cardiotoxicity induced by doxorubicin was accompanied by NADH redox state, mitochondrial membrane potential, and glucose uptake reduction. Inhibition of mitochondrial permeability transition pore opening by cyclosporine A largely prevented mitochondrial membrane potential dissipation, cardiac energy state and dysfunction. These results suggest that in intact hearts an impairment of mitochondrial metabolism is involved in the development of doxorubicin cardiotoxicity.

Fuel-Cell Structure Prevents Membrane Drying

Science.gov (United States)

Mcelroy, J.

1986-01-01

Embossed plates direct flows of reactants and coolant. Membrane-type fuel-cell battery has improved reactant flow and heat removal. Compact, lightweight battery produces high current and power without drying of membranes.

Multi-functional electrospun antibacterial core-shell nanofibrous membranes for prolonged prevention of post-surgical tendon adhesion and inflammation.

Science.gov (United States)

Shalumon, K T; Sheu, Chialin; Chen, Chih-Hao; Chen, Shih-Heng; Jose, Gils; Kuo, Chang-Yi; Chen, Jyh-Ping

2018-05-01

The possibility of endowing an electrospun anti-adhesive barrier membrane with multi-functionality, such as lubrication, prevention of fibroblast attachment and anti-infection and anti-inflammation properties, is highly desirable for the management of post-surgical tendon adhesion. To this end, we fabricated core-shell nanofibrous membranes (CSNMs) with embedded silver nanoparticles (Ag NPs) in the poly(ethylene glycol) (PEG)/poly(caprolactone) (PCL) shell and hyaluronic acid (HA)/ibuprofen in the core. HA imparted a lubrication effect for smooth tendon gliding and reduced fibroblast attachment, while Ag NPs and ibuprofen functioned as anti-infection and anti-inflammation agents, respectively. CSNMs with a PEG/PCL/Ag shell (PPA) and HA core containing 0% (H/PPA), 10% (HI10/PPA), 30% (HI30/PPA) and 50% (HI50/PPA) ibuprofen were fabricated through co-axial electrospinning and assessed through microscopic, spectroscopic, thermal, mechanical and drug release analyses. Considering nutrient passage through the barrier, the microporous CSNMs exerted the same barrier effect but drastically increased the mass transfer coefficients of bovine serum albumin compared with the commercial anti-adhesive membrane SurgiWrap®. Cell attachment/focal adhesion formation of fibroblasts revealed effective reduction of initial cell attachment on the CSNM surface with minimum cytotoxicity (except HI50/PPA). The anti-bacterial effect against both Gram-negative and Gram-positive bacteria was verified to be due to the Ag NPs in the membranes. In vivo studies using H/PPA and HI30/PPA CSNMs and SurgiWrap® in a rabbit flexor tendon rupture model demonstrated the improved efficacy of HI30/PPA CSNMs in reducing inflammation and tendon adhesion formation based on gross observation, histological analysis and functional assays. We conclude that HI30/PPA CSNMs can act as a multifunctional barrier membrane to prevent peritendinous adhesion after tendon surgery. A multi-functional anti-adhesion barrier

Resistência ao cisalhamento de um selante associado a componentes de um sistema adesivo dental Shear bond strength of an enamel sealant using components of a dental adhesive system

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Zilda Maria MUSSOLINO

1998-10-01

Full Text Available Cilindros de selante, padronizados, foram unidos ao esmalte das superfícies vestibulares de incisivos bovinos, após serem planificadas e condicionadas, com ácido fosfórico a 37%, durante 30 segundos. Foram utilizados 40 dentes, aleatoriamente divididos em 4 grupos, cujas coroas foram secionadas, de modo a obter-se duas porções, cervical e incisal. No Grupo I, após o condicionamento, aplicou-se o selante Fluroshield; no Grupo II, antes da aplicação do selante, uma camada do "primer" do Probond foi aplicada; no Grupo III, após o "primer", aplicou-se o adesivo do Probond; e no Grupo IV, somente o adesivo foi aplicado antes do selante. Os espécimes foram armazenados em água a 37°C, durante 36 horas, e então submetidos aos ensaios de cisalhamento. A análise estatística revelou significante diminuição na resistência ao cisalhamento, quando o "primer" foi aplicado previamente ao selante, enquanto a resistência ao cisalhamento do selante foi semelhante quando o adesivo do Probond foi aplicado, com ou sem o "primer". A resistência ao cisalhamento do selante ao esmalte é maior no terço incisal que no terço cervical da coroa.Standardized cylinders of sealants were bonded to the flattened labial enamel of bovine incisor teeth that had previously been subjected to 37% phosphoric acid gel for 30 seconds. A total of 40 teeth were tested, randomly divided in four groups of 10 teeth each. In Group I, the sealant Fluroshield was applied after etching; in Group II after etching, the "primer" of Probond was used before the sealant; in Group III after etching, the bond of Probond was used after the "primer"; and in Group IV only the bond was applied before the sealant. Specimens were stored in water at 37°C during 36 hours, before shear testing using a Universal Testing Machine. There was significant reduction in shear bond strength of the sealant when only the "primer" was used previously to the application of the sealant. There were no

Modification of Salmonella Lipopolysaccharides Prevents the Outer Membrane Penetration of Novobiocin

Energy Technology Data Exchange (ETDEWEB)

Nobre, Thatyane M.; Martynowycz, Michael W.; Andreev, Konstantin; Kuzmenko, Ivan; Nikaido, Hiroshi; Gidalevitz, David

2015-12-01

Small hydrophilic antibiotics traverse the outer membrane of Gram-negative bacteria through porin channels. Large lipophilic agents traverse the outer membrane through its bilayer, containing a majority of lipopolysaccharides in its outer leaflet. Genes controlled by the two-component regulatory system PhoPQ modify lipopolysaccharides. We isolate lipopolysaccharides from isogenic mutants of Salmonella sp., one lacking the modification, the other fully modified. These lipopolysaccharides were reconstituted asmonolayers at the air-water interface, and their properties, aswell as their interaction with a large lipophilic drug, novobiocin, was studied. X-ray reflectivity showed that the drug penetrated the monolayer of the unmodified lipopolysaccharides reaching the hydrophobic region,butwas prevented fromthis penetration intothemodified lipopolysaccharides.Results correlatewith behavior of bacterial cells, which become resistant to antibiotics after PhoPQ-regulated modifications. Grazing incidence x-ray diffraction showed that novobiocin produced a striking increase in crystalline coherence length, and the size of the near-crystalline domains.

Cost-effectiveness, in a randomized trial, of glass-ionomer-based and resin sealant materials after 4 yr

NARCIS (Netherlands)

Goldman, A.S.; Chen, X.; Fan, M.; Frencken, J.E.

2016-01-01

This study, conducted from a government program perspective, compared the incremental cost-effectiveness of oral health interventions, in particular their delivery to underserved populations in whom dental sealants constitute an important, high-yielding complement to toothbrushing in dental-caries

A case history on long-term effectiveness of clay sealant

International Nuclear Information System (INIS)

Lee, C.F.

1986-01-01

This report documents a case history in which a cadaver and the associated burial objects were found to be well-preserved after more than 2100 years of burial in Southern China. The preservation was attributed to the presence of a 60-300 cm thick kaolin or white clay layer around the tomb, which acted effectively as a barrier to moisture and air percolation. The degree of preservation in other tombs of similar age in the same area apparently depended on the mineralogy and thickness of the clay sealants used. The implication of this case history to nuclear fuel waste disposal is discussed

Validation of micro-CT against the section method regarding the assessment of marginal leakage of sealants.

NARCIS (Netherlands)

Chen, X.; Cuijpers, V.M.J.I.; Fan, M.W.; Frencken, J.E.F.M.

2012-01-01

BACKGROUND: The aim of this study was to validate the micro-CT and related software against the section method using the stereomicroscope for marginal leakage assessment along the sealant-enamel interface. METHODS: Pits and fissures of the occlusal surface of 10 teeth were sealed with a

A Comparative Evaluation of the Effect of Bonding Agent on the Tensile Bond Strength of Two Pit and Fissure Sealants Using Invasive and Non-invasive Techniques: An in-vitro Study.

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Singh, Shamsher; Adlakha, Vivek; Babaji, Prashant; Chandna, Preetika; Thomas, Abi M; Chopra, Saroj

2013-10-01

Newer technologies and the development of pit and fissure sealants have shifted the treatment philosophy from 'drill and fill' to that of 'seal and heal'. The purpose of this in-vitro study was to evaluate the effects of bonding agents on the tensile bond strengths of two pit and fissure sealants by using invasive and non-invasive techniques. One hundred and twenty bicuspids were collected and teeth were divided into two groups: Group-I (Clinpro) and Group-II (Conseal f) with 60 teeth in each group. For evaluating tensile bond strengths, occlusal surfaces of all the teeth were flattened by reducing buccal and lingual cusps without disturbing fissures. Standardised polyvinyl tube was bonded to occlusal surfaces with respective materials. Sealants were applied, with or without bonding agents, in increments and they were light cured. Tensile bond strengths were determined by using Universal Testing Machine. Data were then statistically analysed by using Student t-test for comparison. A statistically significant difference was found in tensile bond strength in invasive with bonding agent group than in non-invasive with bonding agent group. This study revealed that invasive techniques increase the tensile bond strengths of sealants as compared to non- invasive techniques and that the use of a bonding agent as an intermediate layer between the tooth and fissure sealant is beneficial for increasing the bond strength.

Successful conservative treatment of enterocutaneous fistula with cyanoacrylate surgical sealant: case report.

Science.gov (United States)

Musa, N; Aquilino, F; Panzera, P; Martines, G

2017-01-01

Enterocutaneous (EC) fistula is an abnormal communication between the gastrointestinal tract and the skin. The majority of EC fistulas result from surgery. Only 15-25% of EC fistulas are spontaneous and they often result from underlying diseases such as Crohn's disease, radiation and chemotherapy. A 62-year old woman who, in 2012, underwent Pylorus-preserving cephalic pancreaticoduodenectomy (PPPD sec. Traverso-Longmire), due to an advanced pancreatic ductal adenocarcinoma (pT3N1M1). After surgery, the patient underwent chemotherapy with folfirinox regimen. In December 2016, as a result of the appearance of metastatic liver lesions and perianastomotic recurrence, the patient underwent second line treatment with Gemcitabine and pab-paclitaxel. After five months from the beginning of this new second line therapy she presented an EC fistula. The fistula of the patient was successfully treated with total parenteral nutrition and with percutaneous injection of cyanoacrylic sealant. The result suggests the advisability of percutaneous injection of sealant devices, such as cyanoacrylate glue; in order to successfully control stable Enterocutaneous fistulas with acceptable morbidity and mortality especially in particular situations, such as, with low output EC fistulas without signs of complications or on patients considered not suitable for surgery, a conservative approach could ensure the control of the fistula. This approach is easy and safe, viable and useful for future trials on the efficacy in conservative treatment of EC fistula.

Motor recovery and synaptic preservation after ventral root avulsion and repair with a fibrin sealant derived from snake venom.

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Roberta Barbizan

Full Text Available BACKGROUND: Ventral root avulsion is an experimental model of proximal axonal injury at the central/peripheral nervous system interface that results in paralysis and poor clinical outcome after restorative surgery. Root reimplantation may decrease neuronal degeneration in such cases. We describe the use of a snake venom-derived fibrin sealant during surgical reconnection of avulsed roots at the spinal cord surface. The present work investigates the effects of this fibrin sealant on functional recovery, neuronal survival, synaptic plasticity, and glial reaction in the spinal motoneuron microenvironment after ventral root reimplantation. METHODOLOGY/PRINCIPAL FINDINGS: Female Lewis rats (7 weeks old were subjected to VRA and root replantation. The animals were divided into two groups: 1 avulsion only and 2 replanted roots with fibrin sealant derived from snake venom. Post-surgical motor performance was evaluated using the CatWalk system twice a week for 12 weeks. The rats were sacrificed 12 weeks after surgery, and their lumbar intumescences were processed for motoneuron counting and immunohistochemistry (GFAP, Iba-1 and synaptophysin antisera. Array based qRT-PCR was used to evaluate gene regulation of several neurotrophic factors and receptors as well as inflammatory related molecules. The results indicated that the root reimplantation with fibrin sealant enhanced motor recovery, preserved the synaptic covering of the motoneurons and improved neuronal survival. The replanted group did not show significant changes in microglial response compared to VRA-only. However, the astroglial reaction was significantly reduced in this group. CONCLUSIONS/SIGNIFICANCE: In conclusion, the present data suggest that the repair of avulsed roots with snake venom fibrin glue at the exact point of detachment results in neuroprotection and preservation of the synaptic network at the microenvironment of the lesioned motoneurons. Also such procedure reduced the

Motor Recovery and Synaptic Preservation after Ventral Root Avulsion and Repair with a Fibrin Sealant Derived from Snake Venom

Science.gov (United States)

Barbizan, Roberta; Castro, Mateus V.; Rodrigues, Antônio C.; Barraviera, Benedito; Ferreira, Rui S.; Oliveira, Alexandre L. R.

2013-01-01

Background Ventral root avulsion is an experimental model of proximal axonal injury at the central/peripheral nervous system interface that results in paralysis and poor clinical outcome after restorative surgery. Root reimplantation may decrease neuronal degeneration in such cases. We describe the use of a snake venom-derived fibrin sealant during surgical reconnection of avulsed roots at the spinal cord surface. The present work investigates the effects of this fibrin sealant on functional recovery, neuronal survival, synaptic plasticity, and glial reaction in the spinal motoneuron microenvironment after ventral root reimplantation. Methodology/Principal Findings Female Lewis rats (7 weeks old) were subjected to VRA and root replantation. The animals were divided into two groups: 1) avulsion only and 2) replanted roots with fibrin sealant derived from snake venom. Post-surgical motor performance was evaluated using the CatWalk system twice a week for 12 weeks. The rats were sacrificed 12 weeks after surgery, and their lumbar intumescences were processed for motoneuron counting and immunohistochemistry (GFAP, Iba-1 and synaptophysin antisera). Array based qRT-PCR was used to evaluate gene regulation of several neurotrophic factors and receptors as well as inflammatory related molecules. The results indicated that the root reimplantation with fibrin sealant enhanced motor recovery, preserved the synaptic covering of the motoneurons and improved neuronal survival. The replanted group did not show significant changes in microglial response compared to VRA-only. However, the astroglial reaction was significantly reduced in this group. Conclusions/Significance In conclusion, the present data suggest that the repair of avulsed roots with snake venom fibrin glue at the exact point of detachment results in neuroprotection and preservation of the synaptic network at the microenvironment of the lesioned motoneurons. Also such procedure reduced the astroglial reaction and

40 CFR Table 3 to Subpart Xxxx of... - Emission Limits for Puncture Sealant Application Affected Sources

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Emission Limits for Puncture Sealant Application Affected Sources 3 Table 3 to Subpart XXXX of Part 63 Protection of Environment ENVIRONMENTAL... Manufacturing Pt. 63, Subpt. XXXX, Table 3 Table 3 to Subpart XXXX of Part 63—Emission Limits for Puncture...

40 CFR Table 4 to Subpart Xxxx of... - Operating Limits for Puncture Sealant Application Control Devices

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Operating Limits for Puncture Sealant Application Control Devices 4 Table 4 to Subpart XXXX of Part 63 Protection of Environment ENVIRONMENTAL... Manufacturing Pt. 63, Subpt. XXXX, Table 4 Table 4 to Subpart XXXX of Part 63—Operating Limits for Puncture...

The cost-effectiveness of three interventions for providing preventive services to low-income children.

Science.gov (United States)

Johnson, Ben; Serban, Nicoleta; Griffin, Paul M; Tomar, Scott L

2017-12-01

We evaluated the impact of loan repayment programmes, revising Medicaid fee-for-service rates, and changing dental hygienist supervision requirements on access to preventive dental care for children in Georgia. We estimated cost savings from the three interventions of preventive care for young children after netting out the intervention cost. We used a regression model to evaluate the impact of changing the Medicaid reimbursement rates. The impact of supervision was evaluated by comparing general and direct supervision in school-based dental sealant programmes. Federal loan repayments to dentists and school-based sealant programmes (SBSPs) had lower intervention costs (with higher potential cost savings) than raising the Medicaid reimbursement rate. General supervision had costs 56% lower than direct supervision of dental hygienists for implementing a SBSP. Raising the Medicaid reimbursement rate by 10 percentage points would improve utilization by Loan repayment could serve almost 13 000 children for a cost of $400 000 and a potential cost saving of $176 000. The three interventions all improved met need for preventive dental care. Raising the reimbursement rate alone would marginally affect utilization of Medicaid services but would not substantially increase acceptance of Medicaid by providers. Both loan repayment programmes and amending supervision requirements are potentially cost-saving interventions. Loan repayment programmes provide complete care to targeted areas, while amending supervision requirements of dental hygienists could provide preventive care across the state. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Soluble products of Escherichia coli induce mitochondrial dysfunction-related sperm membrane lipid peroxidation which is prevented by lactobacilli.

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Arcangelo Barbonetti

Full Text Available Unidentified soluble factors secreted by E. coli, a frequently isolated microorganism in genitourinary infections, have been reported to inhibit mitochondrial membrane potential (ΔΨm, motility and vitality of human spermatozoa. Here we explore the mechanisms involved in the adverse impact of E. coli on sperm motility, focusing mainly on sperm mitochondrial function and possible membrane damage induced by mitochondrial-generated reactive oxygen species (ROS. Furthermore, as lactobacilli, which dominate the vaginal ecosystem of healthy women, have been shown to exert anti-oxidant protective effects on spermatozoa, we also evaluated whether soluble products from these microorganisms could protect spermatozoa against the effects of E. coli. We assessed motility (by computer-aided semen analysis, ΔΨm (with JC-1 dye by flow cytometry, mitochondrial ROS generation (with MitoSOX red dye by flow cytometry and membrane lipid-peroxidation (with the fluorophore BODIPY C11 by flow cytometry of sperm suspensions exposed to E. coli in the presence and in the absence of a combination of 3 selected strains of lactobacilli (L. brevis, L. salivarius, L. plantarum. A Transwell system was used to avoid direct contact between spermatozoa and microorganisms. Soluble products of E. coli induced ΔΨm loss, mitochondrial generation of ROS and membrane lipid-peroxidation, resulting in motility loss. Soluble factors of lactobacilli prevented membrane lipid-peroxidation of E. coli-exposed spermatozoa, thus preserving their motility. In conclusion, sperm motility loss by soluble products of E. coli reflects a mitochondrial dysfunction-related membrane lipid-peroxidation. Lactobacilli could protect spermatozoa in the presence of vaginal disorders, by preventing ROS-induced membrane damage.

Analysing uncertainty around costs of innovative medical technologies: the case of fibrin sealant (QUIXIL) for total knee replacement.

NARCIS (Netherlands)

Steuten, Lotte Maria Gertruda; Vallejo-Torres, Laura; Bastide, Philippe; Buxton, Martin J.

2009-01-01

This paper presents a relatively simple cost model comparing the costs of using a commercial fibrin sealant (QUIXIL®) in addition to conventional haemostatic treatment vs. conventional treatment alone in total knee replacement (TKR) surgery, and demonstrates and discusses how one- and two-way

Autologous but not Fibrin Sealant Patches for Stump Coverage Reduce Clinically Relevant Pancreatic Fistula in Distal Pancreatectomy: A Systematic Review and Meta-analysis.

Science.gov (United States)

Weniger, Maximilian; D'Haese, Jan Goesta; Crispin, Alexander; Angele, Martin Kurt; Werner, Jens; Hartwig, Werner

2016-11-01

Postoperative pancreatic fistula (POPF) causes significant morbidity and mortality after distal pancreatectomy. Patch coverage of the pancreatic stump is often used with the intention to prevent POPF. Despite numerous investigations, the effects of patch coverage remain unclear. The present meta-analysis aims to clarify the effects of patch coverage in distal pancreatectomy on the incidence of POPF. A systematic search of MEDLINE/PubMed and the Cochrane Database according to the PRISMA Statement was performed. Subsequently a meta-analysis on rates and overall incidence of POPF and length of hospital stay was carried out. By applying the inverse variance weighting method, the combined effect size and 95 % confidence interval were calculated. Heterogeneity was assessed using I 2 statistics. Five randomized controlled trials and six observational clinical studies were included for final analysis. A cumulative incidence of 43 % of POPF grades A-C was identified. Patch coverage in distal pancreatectomy is significantly associated with a decreased rate of POPF grade C (p = 0.006). Patches of autologous vascularized tissue significantly reduce the overall incidence of POPF (p = 0.04) and clinically relevant POPF grade B and C (p = 0.002). Fibrin sealant patches do not influence rates of POPF after distal pancreatectomy. None of the outcomes evaluated showed adverse results for the patch group. Patch coverage after distal pancreatectomy can reduce the rate of POPF. Patch coverage with autologous vascularized tissue but not fibrin sealant patches may be used to reduce clinically relevant POPF and postoperative morbidity in distal pancreatectomy.

Evaluation of Fibrin Sealants and Tissue Adhesives in Oral Surgery for Patients with Bleeding Disorders

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Gülsüm Ak

2012-03-01

Full Text Available OBJECTIVE: The aim of this study was to evaluate the efficiency of two local haemostatic agents administered together with preoperative dose of replacement therapy for oral surgical procedures in patients with bleeding disorders METHODS: Twenty-one patients were divided into three groups randomly. Patients in Group 1 (n=7 received preoperative replacement therapy with postoperative fibrin sealant application in the surgical site. Patients in Group 2 (n=7 received preoperative replacement therapy with postoperative tissue adhesive application in the surgical site. Patients in Group 3 (n=7 were given total dose of replacement therapy pre- and postoperatively. RESULTS: No postoperative bleeding was observed in 17 patients including five patients in Group 1 (71.42%, six patients in Group 2 (85.71% and six patients in Group 3 (85.71%. Haemorrhagic complication was observed in only four patients among all groups. CONCLUSION: We conclude that utilization of fibrin sealants and tissue adhesives in oral surgery is beneficial due to the lessened amount of factor concentrates used for replacement therapy and the rapid haemostasis at the operation side to perform serial surgical procedures in the same session.

Photosynthetic solar cell using nanostructured proton exchange membrane for microbial biofilm prevention.

Science.gov (United States)

Lee, Dong Hyun; Oh, Hwa Jin; Bai, Seoung Jae; Song, Young Seok

2014-06-24

Unwanted biofilm formation has a detrimental effect on bioelectrical energy harvesting in microbial cells. This issue still needs to be solved for higher power and longer durability and could be resolved with the help of nanoengineering in designing and manufacturing. Here, we demonstrate a photosynthetic solar cell (PSC) that contains a nanostructure to prevent the formation of biofilm by micro-organisms. Nanostructures were fabricated using nanoimprint lithography, where a film heater array system was introduced to precisely control the local wall temperature. To understand the heat and mass transfer phenomena behind the manufacturing and energy harvesting processes of PSC, we carried out a numerical simulation and experimental measurements. It revealed that the nanostructures developed on the proton exchange membrane enable PSC to produce enhanced output power due to the retarded microbial attachment on the Nafion membrane. We anticipate that this strategy can provide a pathway where PSC can ensure more renewable, sustainable, and efficient energy harvesting performance.

Dextran/Albumin hydrogel sealant for Dacron(R) vascular prosthesis.

Science.gov (United States)

Lisman, Anna; Butruk, Beata; Wasiak, Iga; Ciach, Tomasz

2014-05-01

In this paper, the authors describe a novel type of hydrogel coating prepared from the copolymer of human serum albumin and oxidized dextran. The material was designed as a hydrogel sealant for polyester (Dacron®)-based vascular grafts. Dextran was chosen as a coating material due to its anti-thrombogenic properties. Prepared hydrogels were compared with similar, already known biomaterial made from gelatine with the same cross-linking agent. Obtained hydrogels, prepared from various ratios of oxidized dextran/albumin or oxidized dextran/gelatine, showed different cross-linking densities, which caused differences in swelling, degradation rate and mechanical properties. Permeability tests confirmed the complete tightness of the hydrogel-modified prosthesis. Results showed that application of the hydrogel coating provided leakage-free prosthesis and eliminated the need of pre-clotting.

Assessment of Pain and Quality of Life in Lichtenstein Hernia Repair Using a New Monofilament PTFE Mesh: Comparison of Suture vs. Fibrin-Sealant Mesh Fixation.

Science.gov (United States)

Fortelny, René H; Petter-Puchner, Alexander H; Redl, Heinz; May, Christopher; Pospischil, Wolfgang; Glaser, Karl

2014-01-01

Inguinal hernia repair is one of the most common operations in general surgery. The Lichtenstein tension-free operation has become the gold standard in open inguinal hernia repair. Despite the low recurrence rates, pain and discomfort remain a problem for a large number of patients. The aim of this study was to compare suture fixation vs. fibrin sealing by using a new monofilament PTFE mesh, i.e., the Infinit(®) mesh by W. L. Gore & Associates. This study was designed as a controlled prospective single-center two-cohort study. A total of 38 patients were enrolled and operated in Lichtenstein technique either standard suture mesh fixation or fibrin-sealant mesh fixation were used as described in the TIMELI trial. Primary outcome parameters were postoperative complications with the new mesh (i.e., seroma, infection), pain, and quality of life evaluated by the VAS and the SF-36 questionnaire. Secondary outcome was recurrence assessed by ultrasound and physical examination. Follow-up time was 1 year. Significantly, less postoperative pain was reported in the fibrin-sealant group compared to the suture group at 6 weeks (P = 0.035), 6 months (P = 0.023), and 1 year (P = 0.011) postoperatively. Additionally, trends toward a higher postoperative quality of life, a faster surgical procedure, and a shorter hospital stay were seen in the fibrin-sealant group. Fibrin-sealant mesh fixation in Lichtenstein hernioplasty effectively reduces acute and chronic postoperative pain. Monofilament, macro-porous, knitted PTFE meshes seem to be a practicable alternative to commonly used polypropylene meshes in open inguinal hernia repair.

Assessment of pain and quality of life in Lichtenstein hernia repair using a new monofilament PTFE mesh: comparison of suture vs. fibrin sealant mesh fixation

Directory of Open Access Journals (Sweden)

René H Fortelny

2014-11-01

Full Text Available Background: Inguinal hernia repair is one of the most common operations in general surgery. The Lichtenstein tension-free operation has become the gold standard in open inguinal hernia repair. Despite the low recurrence rates, pain and discomfort remain a problem for a large number of patients. The aim of this study was to compare suture fixation vs. fibrin sealing by using a new monofilament PTFE mesh, i.e. the Infinit® mesh by W. L. Gore & Associates. Methods: This study was designed as a controlled prospective single-centre two cohort study. A total of 38 patients were enrolled and operated in Lichtenstein technique either standard suture mesh fixation or fibrin sealant mesh fixation were used as described in the TIMELI trial. Primary outcome parameters were postoperative complications with the new mesh (i.e. seroma, infection, pain and quality of life evaluated by the VAS and the SF-36 questionnaire. Secondary outcome was recurrence assessed by ultrasound and physical examination. Follow-up time was 1 year.Results: Significantly less postoperative pain was reported in the fibrin sealant group compared to the suture group at 6 weeks (P=0.035, 6 months (P=0.023 and 1 year (P=0.011 postoperatively. Additionally trends towards a higher postoperative quality of life, a faster surgical procedure and a shorter hospital stay were seen in the fibrin sealant group.Conclusion: Fibrin sealant mesh fixation in Lichtenstein hernioplasty effectively reduces acute and chronic postoperative pain. Monofilament, macro-porous, knitted PTFE meshes seem to be a practicable alternative to commonly used polypropylene meshes in open inguinal hernia repair.

Pretreatment and Membrane Hydrophilic Modification to Reduce Membrane Fouling

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Huaqiang Chu

2013-09-01

Full Text Available The application of low pressure membranes (microfiltration/ultrafiltration has undergone accelerated development for drinking water production. However, the major obstacle encountered in its popularization is membrane fouling caused by natural organic matter (NOM. This paper firstly summarizes the two factors causing the organic membrane fouling, including molecular weight (MW and hydrophilicity/hydrophobicity of NOM, and then presents a brief introduction of the methods which can prevent membrane fouling such as pretreatment of the feed water (e.g., coagulation, adsorption, and pre-oxidation and membrane hydrophilic modification (e.g., plasma modification, irradiation grafting modification, surface coating modification, blend modification, etc.. Perspectives of further research are also discussed.

40 CFR Table 14 to Subpart Xxxx of... - Continuous Compliance With the Emission Limitations for Puncture Sealant Application Affected...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Continuous Compliance With the Emission Limitations for Puncture Sealant Application Affected Sources 14 Table 14 to Subpart XXXX of Part 63... Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 14 Table 14 to Subpart XXXX...

Influence of surface sealant on the translucency of composite resin: effect of immersion time and immersion media

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Patrícia Petromilli Nordi Sasso Garcia

2008-06-01

Full Text Available This study evaluated the effect of surface sealant on the translucency of composite resin immersed in different solutions. The study involved the following materials: Charisma, Fortify and coffee, Coca-Cola®, tea and artificial saliva as solutions. Sixty-four specimens (n = 8 were manufactured and immersed in artificial saliva at 37 ± 1 °C. Samples were immersed in the solutions for three times a day and re-immersed in artificial saliva until the translucency readings. The measurements were carried out at nine times: T1 - 24 hours after specimen preparation, T2 - 24 hours after immersion in the solutions, T3 - 48 hours and T4 to T9 - 7, 14, 21, 30, 60 and 90 days, respectively, after immersion. The translucency values were measured using a JOUAN device. The results were subjected to ANOVA and Tukey's test at 5%. The surface sealant was not able to protect the composite resin against staining, the coffee showed the strongest staining action, followed by tea and regarding immersion time, a significant alteration was noted in the translucency of composite resin after 21 days.

Autologous fibrin sealant reduces the incidence of prolonged air leak and duration of chest tube drainage after lung volume reduction surgery: a prospective randomized blinded study.

Science.gov (United States)

Moser, C; Opitz, I; Zhai, W; Rousson, V; Russi, E W; Weder, W; Lardinois, D

2008-10-01

Prolonged air leak is reported in up to 50% of patients after lung volume reduction surgery. The effect of an autologous fibrin sealant on the intensity and duration of air leak and on the time to chest drain removal after lung volume reduction surgery was investigated in a randomized prospective clinical trial. Twenty-five patients underwent bilateral thoracoscopic lung volume reduction surgery. In each patient, an autologous fibrin sealant was applied along the staple lines on one side, whereas no additional measure was taken on the other side. Randomization of treatment was performed at the end of the resection on the first side. Air leak was assessed semiquantitatively by use of a severity score (0 = no leak; 4 = continuous severe leak) by two investigators blinded to the treatment. Mean value of the total severity scores for the first 48 hours postoperative was significantly lower in the treated group (4.7 +/- 7.7) than in the control group (16.0 +/- 10.1) (P drainage were also significantly reduced after application of the sealant (4.5% and 2.8 +/- 1.9 days versus 31.8% and 5.9 +/- 2.9 days) (P = .03 and P drainage.

Pilot demonstration of energy-efficient membrane bioreactor (MBR) using reciprocating submerged membrane.

Science.gov (United States)

Ho, Jaeho; Smith, Shaleena; Patamasank, Jaren; Tontcheva, Petia; Kim, Gyu Dong; Roh, Hyung Keun

2015-03-01

Membrane bioreactor (MBR) is becoming popular for advanced wastewater treatment and water reuse. Air scouring to "shake" the membrane fibers is most suitable and applicable to maintain filtration without severe and rapidfouling. However, membrane fouling mitigating technologies are energy intensive. The goal of this research is to develop an alternative energy-saving MBR system to reduce energy consumption; a revolutionary system that will directly compete with air scouring technologies currently in the membrane water reuse market. The innovative MBR system, called reciprocation MBR (rMBR), prevents membrane fouling without the use of air scouring blowers. The mechanism featured is a mechanical reciprocating membrane frame that uses inertia to prevent fouling. Direct strong agitation of the fiber is also beneficial for the constant removal of solids built up on the membrane surface. The rMBR pilot consumes less energy than conventional coarse air scouring MBR systems. Specific energy consumption for membrane reciprocation for the pilot rMBR system was 0.072 kWh/m3 permeate produced at 40 LMH, which is 75% less than the conventional air scouring in an MBR system (0.29 kWh/m3). Reciprocation of the hollow-fiber membrane can overcome the hydrodynamic limitations of air scouring or cross-flow membrane systems with less energy consumption and/or higher energy efficiency.

Bilateral PLA/alginate membranes for the prevention of postsurgical adhesions.

Science.gov (United States)

Kessler, Martina; Esser, Eva; Groll, Jürgen; Tessmar, Jörg

2016-11-01

A bilateral barrier membrane for the prevention of postsurgical adhesions was developed. Thereby, a smooth PLA side was supposed to keep the affected tissues glidingly separated, while a mucoadhesive side made of alginate was meant to keep the barrier resident on the site of injury so that suturing becomes redundant or at least the membrane stays long enough to facilitate surgical handling. Because hydrophilic alginate and lipophilic PLA films show only low cohesion, solution electrospun meshes of PLA and PLA-PEG-PLA triblock copolymers with varying poly(ethylene glycol) [PEG] content were investigated as cohesion promoter to avoid an easy separation of the functionally different layers. Using direct electrospinning onto the PLA film, a modified contact surface of the mesh was created, which allowed the tested alginate solutions (3%, 5%) to infiltrate to different extents. Thereby, an increasing content of hydrophilic PEG within the mesh copolymer and a lower alginate concentration facilitated the infiltration. As a result, the PLA film with a PLA35k-PEG10k-PLA35k (racemic PLA chains) mesh and an alginate layer cast from a 3% alginate solution appeared to be the most effective combination as examined by means of a t peel test, a mucoadhesion test, a tensile test and optical evaluations. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1563-1570, 2016. © 2015 Wiley Periodicals, Inc.

DIDS prevents ischemic membrane degradation in cultured hippocampal neurons by inhibiting matrix metalloproteinase release.

Directory of Open Access Journals (Sweden)

Matthew E Pamenter

prevented stimulus-evoked release of von Willebrand Factor from human umbilical vein endothelial cells. We conclude that DIDS inhibits MMP exocytosis and through this mechanism preserves neuronal membrane integrity during pathological stress.

Detection of occlusal caries with impedance spectroscopy and laser fluorescence before and after placement of fissure sealants: An in vitro study

DEFF Research Database (Denmark)

Mortensen, Diana; Ekstrand, Kim; Twetman, Svante

2016-01-01

, the DIAGNOdent pen and ICDAS at baseline, after bleaching, etching and placement of a clear fissure sealant. A digital radiograph was exposed at baseline. After the assessments, the actual lesion depth was histologically determined.  Results : Bleaching did not affect the readings but significantly higher ACIS...

Role of the membrane skeleton in preventing the shedding of procoagulant-rich microvesicles from the platelet plasma membrane

OpenAIRE

1990-01-01

The platelet plasma membrane is lined by a membrane skeleton that appears to contain short actin filaments cross-linked by actin-binding protein. Actin-binding protein is in turn associated with specific plasma membrane glycoproteins. The aim of this study was to determine whether the membrane skeleton regulates properties of the plasma membrane. Platelets were incubated with agents that disrupted the association of the membrane skeleton with membrane glycoproteins. The consequences of this c...

Exploring the biophysical properties of phytosterols in the plasma membrane for novel cancer prevention strategies.

Science.gov (United States)

Fakih, Omar; Sanver, Didem; Kane, David; Thorne, James L

2018-05-03

Cancer is a global problem with no sign that incidences are reducing. The great costs associated with curing cancer, through developing novel treatments and applying patented therapies, is an increasing burden to developed and developing nations alike. These financial and societal problems will be alleviated by research efforts into prevention, or treatments that utilise off-patent or repurposed agents. Phytosterols are natural components of the diet found in an array of seeds, nuts and vegetables and have been added to several consumer food products for the management of cardio-vascular disease through their ability to lower LDL-cholesterol levels. In this review, we provide a connected view between the fields of structural biophysics and cellular and molecular biology to evaluate the growing evidence that phytosterols impair oncogenic pathways in a range of cancer types. The current state of understanding of how phytosterols alter the biophysical properties of plasma membrane is described, and the potential for phytosterols to be repurposed from cardio-vascular to oncology therapeutics. Through an overview of the types of biophysical and molecular biology experiments that have been performed to date, this review informs the reader of the molecular and biophysical mechanisms through which phytosterols could have anti-cancer properties via their interactions with the plasma cell membrane. We also outline emerging and under-explored areas such as computational modelling, improved biomimetic membranes and ex vivo tissue evaluation. Focus of future research in these areas should improve understanding, not just of phytosterols in cancer cell biology but also to give insights into the interaction between the plasma membrane and the genome. These fields are increasingly providing meaningful biological and clinical data but iterative experiments between molecular biology assays, biosynthetic membrane studies and computational membrane modelling improve and refine our

Characterization of Fast-Scan Cyclic Voltammetric Electrodes Using Paraffin as an Effective Sealant with In Vitro and In Vivo Applications.

Science.gov (United States)

Ramsson, Eric S; Cholger, Daniel; Dionise, Albert; Poirier, Nicholas; Andrus, Avery; Curtiss, Randi

2015-01-01

Fast-scan cyclic voltammetry (FSCV) is a powerful technique for measuring sub-second changes in neurotransmitter levels. A great time-limiting factor in the use of FSCV is the production of high-quality recording electrodes; common recording electrodes consist of cylindrical carbon fiber encased in borosilicate glass. When the borosilicate is heated and pulled, the molten glass ideally forms a tight seal around the carbon fiber cylinder. It is often difficult, however, to guarantee a perfect seal between the glass and carbon. Indeed, much of the time spent creating electrodes is in an effort to find a good seal. Even though epoxy resins can be useful in this regard, they are irreversible (seals are permanent), wasteful (epoxy cannot be reused once hardener is added), hazardous (hardeners are often caustic), and require curing. Herein we characterize paraffin as an electrode sealant for FSCV microelectrodes. Paraffin boasts the advantages of near-immediate curing times, simplicity in use, long shelf-life and stable waterproof seals capable of withstanding extended cycling. Borosilicate electrode tips were left intact or broken and dipped in paraffin embedding wax. Excess wax was removed from the carbon surface with xyelenes or by repeated cycling at an extended waveform (-0.4 to 1.4V, 400 V/s, 60 Hz). Then, the waveform was switched to a standard waveform (-0.4 to 1.3V, 400 V/s, 10 Hz) and cycled until stable. Wax-sealing does not inhibit electrode sensitivity, as electrodes detected linear changes in dopamine before and after wax (then xylenes) exposure. Paraffin seals are intact after 11 days of implantation in the mouse, and still capable of measuring transient changes in in vivo dopamine. From this it is clear that paraffin wax is an effective sealant for FSCV electrodes that provides a convenient substitute to epoxy sealants.

Fluorides and Other Preventive Strategies for Tooth Decay.

Science.gov (United States)

Horst, Jeremy A; Tanzer, Jason M; Milgrom, Peter M

2018-04-01

We focus on scalable public health interventions that prevent and delay the development of caries and enhance resistance to dental caries lesions. These interventions should occur throughout the life cycle, and need to be age appropriate. Mitigating disease transmission and enhancing resistance are achieved through use of various fluorides, sugar substitutes, mechanical barriers such as pit-and-fissure sealants, and antimicrobials. A key aspect is counseling and other behavioral interventions that are designed to promote use of disease transmission-inhibiting and tooth resistance-enhancing agents. Advocacy for public water fluoridation and sugar taxes is an appropriate dental public health activity. Copyright © 2017 Elsevier Inc. All rights reserved.

Coal-tar pavement sealants might substantially increase children's PAH exposures

Science.gov (United States)

Williams, E. Spencer; Mahler, Barbara J.; Van Metre, Peter C.

2012-01-01

Dietary ingestion has been identified repeatedly as the primary route of human exposure to polycyclic aromatic hydrocarbons (PAHs), seven of which are classified as probable human carcinogens (B2 PAHs) by the U.S. EPA. Humans are exposed to PAHs through ingestion of cooked and uncooked foods, incidental ingestion of soil and dust, inhalation of ambient air, and absorption through skin. Although PAH sources are ubiquitous in the environment, one recently identified PAH source stands out: Coal-tar-based pavement sealant—a product applied to many parking lots, driveways, and even playgrounds primarily in the central, southern, and eastern U.S.—has PAH concentrations 100–1000 times greater than most other PAH sources. It was reported recently that PAH concentrations in house dust in residences adjacent to parking lots with coal-tar-based sealant were 25 times higher than in residences adjacent to unsealed asphalt parking lots.

Kebutuhan Fisur Silen Gigi Posterior pada Murid-Murid Sekolah Dasar di Kota Madya Medan

Directory of Open Access Journals (Sweden)

Lina Natamiharja

2015-10-01

Full Text Available The application of pit and fissure sealants is widely accepted practice in carious prevention, these materials were developed in an effort to prevent plaque, bacteria and carbohydrates penetrating pits and fissures of the teeth. Fissure sealants are effective in preventing occlusal carious in 33 out of every 100 teeth. The purpose of this study was to determine the needs of fissure sealant among the children age 6-13 years old. This study was carried out in two elementary schools. Samples was taken by sistematic random sampling based on age and sex. The totals of samples was 430 children. The needs of fissure sealant in the molars were quite high (36,75%, the highest percentage was in the lower first molar (49,64%, followed by the lower second molar (42,92%. In the premolars the needs was low (8,02%, the greatest needs was in the lower second premolar (15,79% followed by upper first premolar (7,50%.

Gas separation membranes

Science.gov (United States)

Schell, William J.

1979-01-01

A dry, fabric supported, polymeric gas separation membrane, such as cellulose acetate, is prepared by casting a solution of the polymer onto a shrinkable fabric preferably formed of synthetic polymers such as polyester or polyamide filaments before washing, stretching or calendering (so called griege goods). The supported membrane is then subjected to gelling, annealing, and drying by solvent exchange. During the processing steps, both the fabric support and the membrane shrink a preselected, controlled amount which prevents curling, wrinkling or cracking of the membrane in flat form or when spirally wound into a gas separation element.

FAM21 directs SNX27–retromer cargoes to the plasma membrane by preventing transport to the Golgi apparatus

Science.gov (United States)

Lee, Seongju; Chang, Jaerak; Blackstone, Craig

2016-01-01

The endosomal network maintains cellular homeostasis by sorting, recycling and degrading endocytosed cargoes. Retromer organizes the endosomal sorting pathway in conjunction with various sorting nexin (SNX) proteins. The SNX27–retromer complex has recently been identified as a major endosomal hub that regulates endosome-to-plasma membrane recycling by preventing lysosomal entry of cargoes. Here, we show that SNX27 directly interacts with FAM21, which also binds retromer, within the Wiskott–Aldrich syndrome protein and SCAR homologue (WASH) complex. This interaction is required for the precise localization of SNX27 at an endosomal subdomain as well as for recycling of SNX27-retromer cargoes. Furthermore, FAM21 prevents cargo transport to the Golgi apparatus by controlling levels of phosphatidylinositol 4-phosphate, which facilitates cargo dissociation at the Golgi. Together, our results demonstrate that the SNX27–retromer–WASH complex directs cargoes to the plasma membrane by blocking their transport to lysosomes and the Golgi. PMID:26956659

Is there evidence that barrier membranes prevent bone resorption in autologous bone grafts during the healing period? A systematic review

NARCIS (Netherlands)

Gielkens, Pepijn F. M.; Bos, Ruud R. M.; Raghoebar, Gerry M.; Stegenga, Boudewijn

2007-01-01

Introduction: Autologous bone is considered the "reference standard" for bone-grafting procedures. A barrier membrane covering an autologous bone graft (guided bone regeneration [GBR]) is expected to prevent graft resorption. Good clinical results have been reported for GBR, although potential

Socket Preservation with d-PTFE Membrane: Histologic Analysis of the Newly Formed Matrix at Membrane Removal.

Science.gov (United States)

Laurito, Domenico; Cugnetto, Riccardo; Lollobrigida, Marco; Guerra, Fabrizio; Vestri, Annarita; Gianno, Francesca; Bosco, Sandro; Lamazza, Luca; De Biase, Alberto

This study aimed to evaluate the efficacy of an exposed high-density polytetrafluoroethylene (d-PTFE) membrane in preventing epithelial migration in postextraction sockets. For this purpose, a histologic description of the newly formed soft tissue underlying the membrane is presented. The periodontal status of the adjacent teeth was also evaluated to assess the gingival response. Ten premolar extraction sockets were treated. After tooth extraction, the sockets were filled with nanocrystalline hydroxyapatite and covered with d-PTFE membranes. Subperiosteal pockets were created to ensure the stability of the membranes. Membranes were left intentionally exposed and were atraumatically removed after 28 days. At that time, a bioptic specimen of the newly formed soft tissue under the membranes was taken. All the histologic samples showed a dense connective tissue without epithelial cells and no signs of foreign body reaction. No significant variation of the periodontal indices was observed on the teeth adjacent to the extraction sites. The study results indicate that exposed d-PTFE membranes can prevent epithelial migration in healing sockets without consequences on the periodontal health.

Avaliação clínica de uma resina composta modificada por poliácido, utilizada como selante oclusal, quando aplicada por dentista, THD e graduando Clinical evaluation of a polyacid-modified resin composite, used as an occlusal sealant, when applied by dentist, dental hygienist and undergraduate

Directory of Open Access Journals (Sweden)

Roberta Tarkany BASTING

1999-04-01

Full Text Available O presente trabalho tem por finalidade comparar as diferenças de retenção de uma resina composta modificada por poliácido (Variglass V.L.C., utilizada como selante oclusal, quando aplicada por dentista, THD e graduando em Odontologia. Foram seladas as superfícies oclusais de 370 primeiros molares permanentes superiores de crianças entre 6 e 8 anos de idade provenientes de escolas públicas do município de Piracicaba. As avaliações clínicas foram realizadas após seis e oito meses da aplicação do selante. Aos seis meses, verificou-se que 78,42% dos selantes clinicamente aceitáveis permaneceram retidos sobre a superfície oclusal. O índice de perdas totais corresponderam a 10,20% do total de selantes aplicados. O melhor índice de retenção total foi obtido quando aplicado por graduando. Aos 12 meses, houve um aumento do número de selantes perdidos (43,79% e conseqüente decréscimo do número de selantes totalmente retidos (18,96%, não havendo diferenças significativas de retenção do selante quando aplicado por dentista, THD e graduando. Nos casos de perdas totais do selante, não se constatou presença de lesão cariosa.The aim of this work is to evaluate the differences of clinical retention of a polyacid-modified resin composite (Variglass V.L.C., used as an occlusal sealant, when applied by dentist, dental hygienist and undergraduate in Dentistry. The occlusal surfaces of 370 superior first molars of children ageing from 6 to 8 years from public schools in Piracicaba, were sealed. The presented data are related to the final evaluation after 6 and 12 months. It was observed that after 6 months, 78.42% of the sealants clinically acceptable, remained on the occlusal surfaces and that the completely lost sealants reached 10.20%. The best results of the sealants retention were obtained when the sealants were applied by an undergraduate. After 12 months, there was an increase of completely lost sealants (43.79% and a decrease of

A comparison of the effect of short-acting and long-acting cloxacillin-based dry-cow therapy on somatic cell counts after calving in cows also given internal teat sealants.

Science.gov (United States)

Whitfield, L K; Laven, R A

2018-01-01

To compare, in cows treated with an internal teat sealant, the effect of short-acting and long-acting cloxacillin-based dry-cow therapy on somatic cell counts (SCC) after calving. Cows from a spring-calving, pasture-based dairy farm in the Manawatu-Whanganui region of New Zealand were randomly allocated to receive either a short-acting cloxacillin and ampicillin dry-cow therapy and internal teat sealant (n=291) or a long-acting cloxacillin and ampicillin dry-cow therapy and internal teat sealant (n=288) at the end of lactation. Cows were managed on-farm with routine husbandry procedures through the dry period and following calving. A multivariable logistic regression model was used to determine the association between length of action of dry-cow therapy and the proportion of cows with a SCC >150,000 cells/mL at the first herd test after calving. Age of cow, mean SCC for the preceding season and interval from calving to the first post-calving herd test were all associated with the proportion of cows with an individual SCC >150,000 cells/mL at the first herd test (pcow therapy was not associated with decreased odds of cows having a SCC >150,000 cells/mL at the first herd test compared with treatment with long-acting dry-cow therapy (OR=0.724; 95% CI=0.40-1.30). In this herd, which routinely used internal teat sealants, the use of short-acting cloxacillin-based dry-cow therapy did not result in an increased proportion of cows with elevated SSC post-calving. This was a single farm, single year study but indicates that in this herd, changing from a long-acting to a short-acting antimicrobial may have no impact on the prevalence of subclinical mastitis.

Bond strength of a pit-and-fissure sealant associated to etch-and-rinse and self-etching adhesive systems to saliva-contaminated enamel: individual vs. simultaneous light curing.

Science.gov (United States)

Gomes-Silva, Jaciara Miranda; Torres, Carolina Paes; Contente, Marta Maria Martins Giamatei; Oliveira, Maria Angélica Hueb de Menezes; Palma-Dibb, Regina Guenka; Borsatto, Maria Cristina

2008-01-01

This study evaluated in vitro the shear bond strength (SBS) of a resin-based pit-and-fissure sealant [Fluroshield (F), Dentsply/Caulk] associated with either an etch-and-rinse [Adper Single Bond 2 (SB), 3M/ESPE] or a self-etching adhesive system [Clearfil S3 Bond (S3), Kuraray Co., Ltd.] to saliva-contaminated enamel, comparing two curing protocols: individual light curing of the adhesive system and the sealant or simultaneous curing of both materials. Mesial and distal enamel surfaces from 45 sound third molars were randomly assigned to 6 groups (n=15), according to the bonding technique: I - F was applied to 37% phosphoric acid etched enamel. The other groups were contaminated with fresh human saliva (0.01 mL; 10 s) after acid etching: II - SB and F were light cured separately; III - SB and F were light cured together; IV - S3 and F were light cured separately; V - S3 and F were light cured simultaneously; VI - F was applied to saliva-contaminated, acid-etched enamel without an intermediate bonding agent layer. SBS was tested to failure in a universal testing machine at 0.5 mm/min. Data were analyzed by one-way ANOVA and Fisher's test (alpha=0.05).The debonded specimens were examined with a stereomicroscope to assess the failure modes. Three representative specimens from each group were observed under scanning electron microscopy for a qualitative analysis. Mean SBS in MPa were: I-12.28 (+/-4.29); II-8.57 (+/-3.19); III-7.97 (+/-2.16); IV-12.56 (+/-3.11); V-11.45 (+/-3.77); and VI-7.47 (+/-1.99). In conclusion, individual or simultaneous curing of the intermediate bonding agent layer and the resin sealant did not seem to affect bond strength to saliva-contaminated enamel. S3/F presented significantly higher SBS than the that of the groups treated with SB etch-and-rinse adhesive system and similar SBS to that of the control group, in which the sealant was applied under ideal dry, noncontaminated conditions.

Bone induction by composites of bioresorbable carriers and demineralized bone in rats: a comparative study of fibrin-collagen paste, fibrin sealant, and polyorthoester with gentamicin

DEFF Research Database (Denmark)

Pinholt, E M; Solheim, E; Bang, G

1992-01-01

fibrin-collagen paste and fibrin sealant inhibited bone induction and produced a chronic inflammation; part of the fibrin-collagen paste was still present at 4 weeks. Polyorthoester with gentamicin was almost completely absorbed, induced minimal tissue reaction, and did not inhibit osteoinduction....

Changing rooster sperm membranes to facilitate cryopreservation

Science.gov (United States)

Cryopreservation damages rooster sperm membranes. Part of this damage is due to membrane transitioning from the fluid to the gel state as temperature is reduced. This damage may be prevented by increasing membrane fluidity at low temperatures by incorporating cholesterol or unsaturated lipids into t...

PLGA nanofiber membranes loaded with epigallocatechin-3-O-gallate are beneficial to prevention of postsurgical adhesions

Directory of Open Access Journals (Sweden)

Shin YC

2014-08-01

both scavenging reactive oxygen species and extending activated partial thromboplastin time. Macroscopic observation after 1 week of surgical treatment revealed that the antiadhesion efficacy of E-PLGA nanofiber membranes was significantly superior to those of untreated controls and pure PLGA equivalents, which was comparable to that of a commercial tissue-adhesion barrier. In conclusion, the E-PLGA hybrid nanofiber can be exploited to craft strategies for the prevention of postsurgical adhesions. Keywords: nanofiber membrane, poly(lactic-co-glycolic acid, epigallocatechin-3-O-gallate, antiadhesion, tissue-adhesion barrier

Timetable for oral prevention in childhood-a current opinion.

Science.gov (United States)

Fleming, Paddy

2015-01-01

Dental caries in young children remains a public health problem particularly for children whose families are socioeconomically deprived. A child's first dental visit should be at approximately 12 months of age and this should facilitate the provision of anticipatory guidance concerning oral health and dental development to the child's parents/guardians. Compliance with dietary advice is of key importance and motivational interviewing shows promise in relation to parents adopting good oral health practices for their children. Twice daily toothbrushing using toothpaste that contains in the range of 1000- 1500ppmF is a most important preventive measure. It is important to use a minimal amount of toothpaste, insure that it is not swallowed, have parental or adult supervision during toothbrushing and avoid rinsing with water following brushing with toothpaste. The professional application of topical fluoride varnish twice yearly is a proven caries preventative measure. The application of pit and fissure sealants to teeth with deep pits and fissures is recommended.

Environmental protection systems for the petroleum industry

International Nuclear Information System (INIS)

Lowe, G.B.

1996-01-01

The transportation of petroleum products and other chemicals can involve spillage and leaks despite being closely controlled. Human error in the loading of road tankers or consumers refuelling their vehicles at service stations can lead to spillage accidents. Seepage through permeable concrete and its expansion joints can occur for diesel underground tanks with serious environmental consequences. This article describes methods which could be adopted by the petroleum industry to prevent these accidental incidents from causing environmental pollution. Service station forecourts could be constructed, using precast concrete hexagonal blocks with dry sand between them and then have a coating of sealant to prevent spills from seeping into ground water. Secondary containment for underground tanks should be given an elastomeric membrane coating. (UK)

Fissure sealants: in vitro evaluation of abrasion wear and superficial roughness

Directory of Open Access Journals (Sweden)

Vanessa Pardi

2008-06-01

Full Text Available The aim of this study was to compare the in vitro wear and superficial roughness of four materials (Delton Dyract Flow, Dentsply; Filtek Flow, Vitremer, 3M ESPE used as fissure sealant in 32 extracted human molars divided in four groups (n = 8 after abrasion with toothbrush/dentifrice. Impressions of each occlusal surface were made to analyze wear and circular specimens were prepared to analyze the roughness. Teeth and specimens were mounted in a toothbrushing machine. The replicas were observed using a SEM to determine the superficial wear. Wear: there were no statistically significant differences either between Delton and Filtek Flow or between Dyract Flow and Vitremer. Roughness: there were no statistical differences between Filtek Flow and Dyract Flow, Dyract Flow and Vitremer, Vitremer and Delton., Considering the clinical practice, if caries activity is present the use of Vitremer is suggested not only for its well known fluoride release, but it presented good roughness results.

Improving Hemocompatibility of Membranes for Extracorporeal Membrane Oxygenators by Grafting Nonthrombogenic Polymer Brushes.

Science.gov (United States)

Obstals, Fabian; Vorobii, Mariia; Riedel, Tomáš; de Los Santos Pereira, Andres; Bruns, Michael; Singh, Smriti; Rodriguez-Emmenegger, Cesar

2018-03-01

Nonthrombogenic modifications of membranes for extracorporeal membrane oxygenators (ECMOs) are of key interest. The absence of hemocompatibility of these membranes and the need of anticoagulation of patients result in severe and potentially life-threatening complications during ECMO treatment. To address the lack of hemocompatibility of the membrane, surface modifications are developed, which act as barriers to protein adsorption on the membrane and, in this way, prevent activation of the coagulation cascade. The modifications are based on nonionic and zwitterionic polymer brushes grafted directly from poly(4-methyl-1-pentene) (TPX) membranes via single electron transfer-living radical polymerization. Notably, this work introduces the first example of well-controlled surface-initiated radical polymerization of zwitterionic brushes. The antifouling layers markedly increase the recalcification time (a proxy of initiation of coagulation) compared to bare TPX membranes. Furthermore, platelet and leukocyte adhesion is drastically decreased, rendering the ECMO membranes hemocompatible. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Amniotic membrane grafts for the prevention of esophageal stricture after circumferential endoscopic submucosal dissection.

Science.gov (United States)

Barret, Maximilien; Pratico, Carlos Alberto; Camus, Marine; Beuvon, Frédéric; Jarraya, Mohamed; Nicco, Carole; Mangialavori, Luigi; Chaussade, Stanislas; Batteux, Frédéric; Prat, Frédéric

2014-01-01

The prevention of esophageal strictures following circumferential mucosal resection remains a major clinical challenge. Human amniotic membrane (AM) is an easily available material, which is widely used in ophthalmology due to its wound healing, anti-inflammatory and anti-fibrotic properties. We studied the effect of AM grafts in the prevention of esophageal stricture after endoscopic submucosal dissection (ESD) in a swine model. In this prospective, randomized controlled trial, 20 swine underwent a 5 cm-long circumferential ESD of the lower esophagus. In the AM Group (n = 10), amniotic membrane grafts were placed on esophageal stents; a subgroup of 5 swine (AM 1 group) was sacrificed on day 14, whereas the other 5 animals (AM 2 group) were kept alive. The esophageal stent (ES) group (n = 5) had ES placement alone after ESD. Another 5 animals served as a control group with only ESD. The prevalence of symptomatic strictures at day 14 was significantly reduced in the AM group and ES groups vs. the control group (33%, 40% and 100%, respectively, p = 0.03); mean esophageal diameter was 5.8±3.6 mm, 6.8±3.3 mm, and 2.6±1.7 mm for AM, ES, and control groups, respectively. Median (range) esophageal fibrosis thickness was 0.87 mm (0.78-1.72), 1.19 mm (0.28-1.95), and 1.65 mm (0.7-1.79) for AM 1, ES, and control groups, respectively. All animals had developed esophageal strictures by day 35. The anti-fibrotic effect of AM on esophageal wound healing after ESD delayed the development of esophageal stricture in our model. However, this benefit was of limited duration in the conditions of our study.

Amniotic membrane grafts for the prevention of esophageal stricture after circumferential endoscopic submucosal dissection.

Directory of Open Access Journals (Sweden)

Maximilien Barret

Full Text Available The prevention of esophageal strictures following circumferential mucosal resection remains a major clinical challenge. Human amniotic membrane (AM is an easily available material, which is widely used in ophthalmology due to its wound healing, anti-inflammatory and anti-fibrotic properties. We studied the effect of AM grafts in the prevention of esophageal stricture after endoscopic submucosal dissection (ESD in a swine model.In this prospective, randomized controlled trial, 20 swine underwent a 5 cm-long circumferential ESD of the lower esophagus. In the AM Group (n = 10, amniotic membrane grafts were placed on esophageal stents; a subgroup of 5 swine (AM 1 group was sacrificed on day 14, whereas the other 5 animals (AM 2 group were kept alive. The esophageal stent (ES group (n = 5 had ES placement alone after ESD. Another 5 animals served as a control group with only ESD.The prevalence of symptomatic strictures at day 14 was significantly reduced in the AM group and ES groups vs. the control group (33%, 40% and 100%, respectively, p = 0.03; mean esophageal diameter was 5.8±3.6 mm, 6.8±3.3 mm, and 2.6±1.7 mm for AM, ES, and control groups, respectively. Median (range esophageal fibrosis thickness was 0.87 mm (0.78-1.72, 1.19 mm (0.28-1.95, and 1.65 mm (0.7-1.79 for AM 1, ES, and control groups, respectively. All animals had developed esophageal strictures by day 35.The anti-fibrotic effect of AM on esophageal wound healing after ESD delayed the development of esophageal stricture in our model. However, this benefit was of limited duration in the conditions of our study.

Clinical observation of corneal lamellar debridement combined with sutureless amniotic membrane transplantation for the treatment of superficial fungal keratitis

Directory of Open Access Journals (Sweden)

Huang Zhang

2014-09-01

Full Text Available AIM:To evaluate the clinical efficacy of corneal lamellar debridement combined with sutureless amniotic membrane transplantation for the treatment of superficial fungal keratitis.METHODS:Totally 22 cases(22 eyeswith superficial fungal keratitis were referred to our hospital from April 2012 to October 2013. The patients with persistent cornea ulcer after treatment of local and systemic antifungal drugs underwent corneal lamellar debridement combined with sutureless amniotic membrane transplantation, and the recipient bed was covered with an amniotic membrane using fibrin sealant during the operation. All patients were still given topical antifungal therapy for 1-2mo after operation. The followed-up time was 3mo or above. We observed the corneal healing and amniotic membrane adhesion by split lamp microscope, and investigated the transformation of amniotic membrane and fungal infection recurrence with confocal microscope. RESULTS: Corneal edema and anterior chamber reaction of 21 patients disappeared gradually, and no amniotic membrane graft dissolved and shed off within 1-2wk postoperatively. Two weeks after operation, the graft integrated into the corneal and the corneal wounds' thickness increased gradually, the corneal epithelium reconstructed and corneas became clear. Four weeks after operation, the corneal scarring developed gradually and fluorescence staining was negative. Nineteen cases' amniotic membranes that adhered with the cornea dissolved 4wk after operation. There were different degrees of corneal nebula or macula remained 3mo postoperatively. All patients' vision improved in varying degrees, except in 1 case with fungal keratitis who had been cured by lamellar keratoplasty.CONCLUSION:Corneal lamellar debridement combined with sutureless amniotic membrane transplantation can effectively remove the foci of inflammation, improve the local efficacy, shorten the operation time, relieve the postoperative reaction, and promote cornea

78 FR 37156 - Airworthiness Directives; Eurocopter France Helicopters

Science.gov (United States)

2013-06-20

... inspecting each jettisonable emergency exit window panel (window) for sealant, and removing any sealant that... prevent failure of the windows to jettison, so helicopter occupants can exit the aircraft during an... comments to the U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor...

Cisplatin impairs rat liver mitochondrial functions by inducing changes on membrane ion permeability: Prevention by thiol group protecting agents

International Nuclear Information System (INIS)

Custodio, Jose B.A.; Cardoso, Carla M.P.; Santos, Maria S.; Almeida, Leonor M.; Vicente, Joaquim A.F.; Fernandes, Maria A.S.

2009-01-01

Cisplatin (CisPt) is the most important platinum anticancer drug widely used in the treatment of head, neck, ovarian and testicular cancers. However, the mechanisms by which CisPt induces cytotoxicity, namely hepatotoxicity, are not completely understood. The goal of this study was to investigate the influence of CisPt on rat liver mitochondrial functions (Ca 2+ -induced mitochondrial permeability transition (MPT), mitochondrial bioenergetics, and mitochondrial oxidative stress) to better understand the mechanism underlying its hepatotoxicity. The effect of thiol group protecting agents and some antioxidants against CisPt-induced mitochondrial damage was also investigated. Treatment of rat liver mitochondria with CisPt (20 nmol/mg protein) induced Ca 2+ -dependent mitochondrial swelling, depolarization of membrane potential (ΔΨ), Ca 2+ release, and NAD(P)H fluorescence intensity decay. These effects were prevented by cyclosporine A (CyA), a potent and specific inhibitor of the MPT. In the concentration range of up to 40 nmol/mg protein, CisPt slightly inhibited state 3 and stimulated state 2 and state 4 respiration rates using succinate as respiratory substrate. The respiratory indexes, respiratory control ratio (RCR) and ADP/O ratios, the ΔΨ, and the ADP phosphorylation rate were also depressed. CisPt induced mitochondrial inner membrane permeabilization to protons (proton leak) but did not induce significant changes on mitochondrial H 2 O 2 generation. All the effects induced by CisPt on rat liver mitochondria were prevented by thiol group protecting agents namely, glutathione (GSH), dithiothreitol (DTT), N-acetyl-L-cysteine (NAC) and cysteine (CYS), whereas superoxide-dismutase (SOD), catalase (CAT) and ascorbate (ASC) were without effect. In conclusion, the anticancer drug CisPt: (1) increases the sensitivity of mitochondria to Ca 2+ -induced MPT; (2) interferes with mitochondrial bioenergetics by increasing mitochondrial inner membrane permeabilization to

A study for the research trends of membranes for proton exchange membrane fuel cells

International Nuclear Information System (INIS)

Sener, T.

2004-01-01

'Full text:' A single PEM fuel cell is comprised of a membrane electrode assembly, two bipolar plates and two fields. Membrane electrode assembly is the basic component of PEM fuel cell due to its cost and function, and it consists a membrane sandwiched between two electrocatalyst layers/electrodes and two gas diffusion layers. Increasing the PEM fuel cell operation temperature from 80 o C to 150-200 o C will prevent electrocatalysts CO poisoning and increase the fuel cell performance. Therefore, membranes must have chemical and mechanical resistance and must keep enough water at high temperatures. The aim of membrane studies through fuel cell commercialization is to produce a less expensive thin membrane with high operation temperature, chemical and mechanical resistance and water adsorption capacity. Within this frame, alternative membrane materials, membrane electrode assembly manufacture and evaluation methods are being studied. In this paper, recent studies are reviewed to give a conclusion for research trends. (author)

Sealing versus partial caries removal in primary molars: a randomized clinical trial

NARCIS (Netherlands)

Hesse, D.; Bonifácio, C.C.; Mendes, F.M.; Braga, M.M.; Imparato, J.C.P.; Raggio, D.P.

2014-01-01

Background The resin-based pit and fissure sealant is considered a successful tool in caries prevention, however there is a growing evidence of its use in controlling already established caries in posterior teeth. The aim of this clinical trial is to verify the efficacy of pit and fissure sealants

Implications for high-precision dose radiation therapy planning or limited surgical resection after percutaneous computed tomography-guided lung nodule biopsy using a tract sealant

Directory of Open Access Journals (Sweden)

Patricia M. de Groot, MD

2018-04-01

Full Text Available Purpose: Precision radiation therapy such as stereotactic body radiation therapy and limited resection are being used more frequently to treat intrathoracic malignancies. Effective local control requires precise radiation target delineation or complete resection. Lung biopsy tracts (LBT on computed tomography (CT scans after the use of tract sealants can mimic malignant tract seeding (MTS and it is unclear whether these LBTs should be included in the calculated tumor volume or resected. This study evaluates the incidence, appearance, evolution, and malignant seeding of LBTs. Methods and materials: A total of 406 lung biopsies were performed in oncology patients using a tract sealant over 19 months. Of these patients, 326 had follow-up CT scans and were included in the study group. Four thoracic radiologists retrospectively analyzed the imaging, and a pathologist examined 10 resected LBTs. Results: A total of 234 of 326 biopsies (72%, including primary lung cancer [n = 98]; metastases [n = 81]; benign [n = 50]; and nondiagnostic [n = 5] showed an LBT on CT. LBTs were identified on imaging 0 to 3 months after biopsy. LBTs were typically straight or serpiginous with a thickness of 2 to 5 mm. Most LBTs were unchanged (92% or decreased (6.3% over time. An increase in LBT thickness/nodularity that was suspicious for MTS occurred in 4 of 234 biopsies (1.7%. MTS only occurred after biopsy of metastases from extrathoracic malignancies, and none occurred in patients with lung cancer. Conclusions: LBTs are common on CT after lung biopsy using a tract sealant. MTS is uncommon and only occurred in patients with extrathoracic malignancies. No MTS was found in patients with primary lung cancer. Accordingly, potential alteration in planned therapy should be considered only in patients with LBTs and extrathoracic malignancies being considered for stereotactic body radiation therapy or wedge resection.

Use of FloSeal Sealant in the Surgical Management of Tubal Ectopic Pregnancy

Directory of Open Access Journals (Sweden)

Mara Clapp

2013-01-01

Full Text Available Background. Surgery is sometimes required for the management of tubal ectopic pregnancies. Historically, surgeons used electrosurgery to obtain hemostasis. Topical hemostatic sealants, such as FloSeal, may decrease the reliance on electrosurgery and reduce thermal injury to the tissue. Case. A 33-year-old G1 P0 received methotrexate for a right tubal pregnancy. The patient became symptomatic six days later and underwent a laparoscopic right salpingotomy. After multiple unsuccessful attempts to obtain hemostasis with electrocoagulation, FloSeal was used and hemostasis was obtained. Six weeks later, a hysterosalpingogram (HSG confirmed tubal patency. The patient subsequently had an intrauterine pregnancy. Conclusion. FloSeal helped to achieve hemostasis during a laparoscopic salpingotomy and preserve tubal patency. FloSeal is an effective alternative and adjunct to electrosurgery in the surgical management of tubal pregnancy.

78 FR 76984 - Airworthiness Directives; Eurocopter France Helicopters

Science.gov (United States)

2013-12-20

... inspecting each jettisonable emergency exit window panel (window) for sealant, and removing any sealant that... prevent failure of the windows to jettison, so helicopter occupants can exit the aircraft during an... Office, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590...

Composite hollow fiber gas-liquid membrane contactors for olefin/paraffin separation

NARCIS (Netherlands)

Nijmeijer, Dorothea C.; Visser, Tymen; Assen, R.; Wessling, Matthias

2004-01-01

Gas¿liquid membrane contactors frequently suffer from undesired wetting of the microporous membrane by the absorption liquid. Stabilization layers at the liquid-side of the microporous membrane potentially prevent this wetting. We apply such stabilized membranes in a membrane contactor using AgNO3

Modification of chitosan membranes with nanosilica particles as polymer electrolyte membranes

Energy Technology Data Exchange (ETDEWEB)

Kusumastuti, Ella, E-mail: ella.kusuma@gmail.com; Siniwi, Widasari Trisna, E-mail: wsiniwi@gmail.com; Mahatmanti, F. Widhi; Jumaeri [Department of Chemistry, Faculty of Mathematics and Natural Sciences, State University of Semarang D6 Building 2" n" d floor, Sekaran Unnes Campus, Gunungpati, Semarang (Indonesia); Atmaja, Lukman; Widiastuti, Nurul [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Tenth November Institute of Technology Keputih ITS Campus, Sukolilo, Surabaya (Indonesia)

2016-04-19

Chitosan has been widely used as polymer matrix for Polymer Electrolyte Membrane (PEM) application replacing Nafion which has shortcomings in terms of high methanol permeability that degrades the performance of fuel cells. Chitosan membranes modification is performed by adding nanosilica to prevent methanol transport through the membrane. Nanosilica is synthesized by sol-gel method and the particle diameter is obtained by analysis using Breunner Emmet Teller (BET) that is 6.59 nm. Nanosilica is mixed with chitosan solution to obtain nanosilica-chitosan as polymer electrolyte membrane. The membranes are synthesized through phase inversion method with nanosilica composition including 0; 0.5; 1; 2; 3; 5; and 10% w/w of chitosan. Characterization of the membranes indicate that the results of water swelling, proton conductivity and methanol permeability of the membrane with 3% nanosilica respectively were 49.23%, 0.231 S/cm, and 5.43 x 10{sup −7} cm{sup 2}/s. Based on the results of membrane selectivity calculation, the optimum membrane is the composition of 3% nanosilica with value 5.91 x 105 S s cm{sup −3}. The results of functional groups analysis with FTIR showed that it was only physical interaction that occurred between chitosan and nanosilica since no significant changes found in peak around the wave number 1000-1250 cm{sup −-1}.

Ascorbic acid prevents nonreceptor specific binding of [3H]-5-hydroxytryptamine to bovine cerebral cortex membranes

International Nuclear Information System (INIS)

Hamblin, M.W.; Adriaenssens, P.I.; Ariani, K.; Cawthon, R.M.; Stratford, C.A.; Tan, G.L.; Ciaranello, R.D.

1987-01-01

[ 3 H]-5-Hydroxytryptamine ([ 3 H]-5-HT) decomposes rapidly when exposed to air in solution at physiological pH if antioxidants are not present. The decomposition products appear to bind to two saturable sites on brain membranes (apparent Kd values = 1-2 and 100-1000 nM). This binding mimics ''specific'' ligand/receptor binding in that it is inhibited by 10 microM unlabeled 5-HT. This inhibition is not competitive, but rather is due to the prevention of [ 3 H]-5-HT breakdown by excess unlabeled 5-HT. Unlike genuine ligand/receptor binding, the binding of [ 3 H]-5-HT breakdown products is essentially irreversible and does not display a tissue distribution consistent with binding to authentic 5-HT receptors. [ 3 H]-5-HT decomposition can be eliminated by the inclusion of 0.05 to 5 mM ascorbic acid. At these concentrations ascorbic acid is not deleterious to reversible [ 3 H]-5-HT binding. When [ 3 H] 5-HT exposure to air occurs in the presence of brain membranes, the apparent antioxidant activity of brain membranes themselves affords protection against [ 3 H]-5-HT degradation equal to ascorbic acid. This protection is effective below final [ 3 H]-5-HT concentrations of 10 nM. Above 10 nM [ 3 H]-5-HT, addition of ascorbic acid or other antioxidants is necessary to avoid the occurrence of additional low affinity (apparent Kd = 15-2000 nM) binding sites that are specific but nonetheless irreversible. When care is taken to limit [ 3 H]-5-HT oxidation, the only reversible and saturable specific binding sites observed are of the 5-HT1 high affinity (Kd = 1-2 nM) type. Radioligand oxidation artifacts may be involved in previous reports of low affinity (Kd = 15-250 nM) [ 3 H]-5-HT binding sites in brain membrane preparations

On-line cake-layer management by trans-membrane pressure steady state assessment in Anaerobic Membrane Bioreactors for wastewater treatment

NARCIS (Netherlands)

Jeison, D.; Lier, van J.B.

2006-01-01

Membrane bioreactors have been increasingly applied for wastewater treatment during the last two decades. High energy requirements and membrane capital costs remains as their main drawback. A new strategy of operation is presented based on a continuous critical flux determination, preventing

Does Chlorination of Seawater Reverse Osmosis Membranes Control Biofouling?

KAUST Repository

Khan, Muhammad Tariq; Hong, Pei-Ying; Nada, Nabil; Croue, Jean Philippe

2015-01-01

Biofouling is the major problem of reverse osmosis (RO) membranes used for desalting seawater (SW). The use of chlorine is a conventional and common practice to control/prevent biofouling. Unlike polyamide RO membranes, cellulose triacetate (CTA) RO membranes display a high chlorine tolerance. Due to this characteristic, CTA membranes are used in most of the RO plants located in the Middle East region where the elevated seawater temperature and water quality promote the risk of membrane biofouling. However, there is no detailed study on the investigation/characterization of CTA-RO membrane fouling. In this investigation, the fouling profile of a full–scale SWRO desalination plant operating with not only continuous chlorination of raw seawater but also intermittent chlorination of CTA-RO membranes was studied. Detailed water quality and membrane fouling analyses were conducted. Profiles of microbiological, inorganic, and organic constituents of analysed fouling layers were extensively discussed. Our results clearly identified biofilm development on these membranes. The incapability of chlorination on preventing biofilm formation on SWRO membranes could be assigned to its failure in effectively reaching throughout the different regions of the permeators. This failure could have occurred due to three main factors: plugging of membrane fibers, chlorine consumption by organics accumulated on the front side fibers, or chlorine adaptation of certain bacterial populations.

Does Chlorination of Seawater Reverse Osmosis Membranes Control Biofouling?

KAUST Repository

Khan, Muhammad Tariq

2015-04-01

Biofouling is the major problem of reverse osmosis (RO) membranes used for desalting seawater (SW). The use of chlorine is a conventional and common practice to control/prevent biofouling. Unlike polyamide RO membranes, cellulose triacetate (CTA) RO membranes display a high chlorine tolerance. Due to this characteristic, CTA membranes are used in most of the RO plants located in the Middle East region where the elevated seawater temperature and water quality promote the risk of membrane biofouling. However, there is no detailed study on the investigation/characterization of CTA-RO membrane fouling. In this investigation, the fouling profile of a full–scale SWRO desalination plant operating with not only continuous chlorination of raw seawater but also intermittent chlorination of CTA-RO membranes was studied. Detailed water quality and membrane fouling analyses were conducted. Profiles of microbiological, inorganic, and organic constituents of analysed fouling layers were extensively discussed. Our results clearly identified biofilm development on these membranes. The incapability of chlorination on preventing biofilm formation on SWRO membranes could be assigned to its failure in effectively reaching throughout the different regions of the permeators. This failure could have occurred due to three main factors: plugging of membrane fibers, chlorine consumption by organics accumulated on the front side fibers, or chlorine adaptation of certain bacterial populations.

Manipulation of host membranes by bacterial effectors.

Science.gov (United States)

Ham, Hyeilin; Sreelatha, Anju; Orth, Kim

2011-07-18

Bacterial pathogens interact with host membranes to trigger a wide range of cellular processes during the course of infection. These processes include alterations to the dynamics between the plasma membrane and the actin cytoskeleton, and subversion of the membrane-associated pathways involved in vesicle trafficking. Such changes facilitate the entry and replication of the pathogen, and prevent its phagocytosis and degradation. In this Review, we describe the manipulation of host membranes by numerous bacterial effectors that target phosphoinositide metabolism, GTPase signalling and autophagy.

The effect of biological sealants and adhesive treatments on matrix metalloproteinase expression during renal injury healing.

Directory of Open Access Journals (Sweden)

José Miguel Lloris-Carsí

Full Text Available Renal injuries are relatively common in cases of abdominal trauma. Adhesives and sealants can be used to repair and preserve damaged organs. Using a rat model, this study explores the activity of different matrix metalloproteinases (MMP during the healing of renal injuries treated by two biological adhesives (TachoSil and GelitaSpon and a new synthetic elastic cyanoacrylate (Adhflex.Renal traumatic injuries were experimentally induced in 90 male Wistar rats by a Stiefel Biopsy Punch in the anterior aspect of the left kidney. Animals were divided into five groups: 1, sham non-injured (n = 3; 2, non-treated standard punch injury (n = 6; 3, punch injury treated with TachoSil (n = 27; 4, punch injury treated with GelitaSpon (n = 27; and, 5, punch injury treated with Adhflex (n = 27. Wound healing was evaluated 2, 6, and 18 days after injury by determining the expression of MMPs, and the histopathological evolution of lesions.Histologically, the wound size at 6 days post-injury was larger in Adhflex-treated samples than in the other treatments, but the scarring tissue was similar at 18 days post-injury. Only the MMPs subtypes 1, 2, 8, 9, and 13 were sufficiently expressed to be quantifiable. Both time since injury and treatment type had a significant influence on MMPs expression. Two days after injury, the expression of MMP8 and MMP9 was predominant. MMP2 expression was greater 6 days after injury. The Adhflex-treated group had a significantly higher MMPs expression than the other treatment groups at all healing stages.All three sealant treatments induced almost similar expression of MMPs than untreated animals indicating a physiological healing process. Given that all renal trauma injuries must be considered emergencies, both biological and synthetic adhesives, such as Adhflex, should be considered as a treatment options.

New separation technique. Catalytically functionated separation membrane

Energy Technology Data Exchange (ETDEWEB)

Urgami, Tadashi [Kansai Univ., Osaka (Japan)

1989-02-01

This report introduces research examples, showing the fundamental principle of the membrane by separating the catalytically functionated separation membrane into enzyme fixing separation membrane, polymerized metal complex separation membrane and polymer catalyst separation membrane. This membrane can achieve both functions of separation and catalytic reaction simultaneously and has sufficient possibility to combine powerful functions. Enzyme fixing separation membrane is prepared by carrier combination method, bridging method or covering method and the enzyme fixing method with polymerized complex in which enzyme is controlled to prevent the activity lowering as much as possible and enzyme is fixed from an aqueous solution into polymer membrane. This membrane is applied to the continuous manufacturing of invert sugar from cane sugar and adsorption and removing of harmful substances from blood by utilizing both micro-capsuled urease and active carbon. Alginic acid-copper (II) complex membrane is used for the polymerized metal complex membrane and polystyrene sulfonate membrane is used for the polymer catalyst separation membrane. 28 refs., 4 figs., 1 tabs.

Comparison of cephalonium alone and in combination with an internal teat sealant for dry cow therapy in seasonally calving dairy cows.

Science.gov (United States)

Bates, A J; Chambers, G; Laven, R A

2016-03-01

To assess the effect of combining an internal teat sealant (ITS) and a long-acting cephalonium-based dry cow therapy (DCT) on the prevalence of cows with a somatic cell count (SCC) >150,000 cells/mL 60-80 days after calving, and the incidence of clinical mastitis diagnosed by farm staff in the first 100 days after calving. Cows from a spring-calving, pasture-based, dairy farm in the South Canterbury region of New Zealand were randomly allocated to receive cephalonium DCT (n=289) or cephalonium and internal teat sealant (n=304) at the end of lactation. Cows were inspected twice daily by farm staff during the dry period and following calving for signs of mastitis. Individual SCC were determined from herd tests conducted in the previous lactation and following calving. Logistic regression models were used to determine relationships with the prevalence of cows with a SCC >150,000 cells/mL after calving, and survival analysis was used to model time to the first case of clinical mastitis following calving at the cow and quarter level. The OR for a cow with a SCC >150,000 cells/mL after calving, including age and individual SCC in the preceding lactation in the model, was 0.53 (95% CI=0.32-0.89) for cows treated with combination therapy compared to cows receiving cephalonium (p=0.017). At the cow level, including age and preceding SCC in the model, the hazard ratio for diagnosis of clinical mastitis by farm staff in the first 100 days of lactation was 0.60 (95% CI=0.39-0.98) for cows treated with combination therapy compared to cows receiving cephalonium (p=0.04). At the quarter level, the hazard ratio for diagnosis of clinical mastitis, with age included in the model, was 0.41 (95% CI=0.23-0.74) for the combination therapy compared to cephalonium alone (pmastitis diagnosed by farm staff in the 100 days after calving, and the prevalence of cows with a SCC >150,000 cells/mL 60-80 days after calving. This study adds to the evidence that the prevention of intra mammary

Stability of Beriplast P fibrin sealant: storage and reconstitution.

Science.gov (United States)

Eberhard, Ulrich; Broder, Martin; Witzke, Günther

2006-04-26

This study was performed to investigate the stability of Beriplast P fibrin sealant (FS) across a range of storage conditions, both pre- and post-reconstitution. Storage stability of the FS was evaluated during long-term refrigeration (24 months) with or without interim storage at elevated temperatures (40 degrees C for 1 week and 25 degrees C for 1 and 3 months). Stability of individual FS components was assessed by measuring: fibrinogen content, Factor XIII activity (FXIII), thrombin activity and aprotinin potency. The package integrity of each component was also checked (sterility testing, moisture content and pH). Storage stability was also evaluated by testing the reconstituted product for adhesion (tearing force testing after mixing the solutions) and sterility. Reconstitution stability was evaluated following 3-months' storage, for up to 50 h post-reconstitution using the same tests as for the storage stability investigations. Pre-defined specifications were met for fibrinogen content, Factor XIII activity, and thrombin activity, demonstrating storage stability. Package integrity and the functionality and sterility of the reconstituted product were confirmed throughout. Reconstitution stability was demonstrated for up to 50 h following reconstitution, in terms of both tearing force and sterility tests. In conclusion, the storage stability of Beriplast P was demonstrated over a range of 24-month storage schedules including interim exposure to elevated temperature, and the reconstituted product was stable for up to 50 h.

Evaluation of a novel approach in the prevention of white spot lesions around orthodontic brackets.

Science.gov (United States)

Yap, J; Walsh, L J; Naser-Ud Din, S; Ngo, H; Manton, D J

2014-03-01

The purpose of this study was to evaluate and compare the relative efficacy of a resin fissure sealant, nano-filled self-adhesive protective coating, resin infiltrant, glass ionomer cement (GIC), and GIC containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) in preventing the formation of subsurface lesions of enamel (SLE) adjacent to orthodontic brackets by acting as an enamel surface sealant (ESS). Eighty-five enamel specimens with molar tubes bonded at their centre were randomly divided into five groups, each treated with a different material at the bracket's periphery. Specimens were stored in an acetate demineralization solution at pH 4.5 for 7 days at 37 °C then imaged using quantitative light-induced fluorescence (QLF) to determine the difference in fluorescence (∆F) between sound- and acid-exposed enamel. Lesion cross-sections were then examined using backscattered scanning electron microscopy (SEM) to measure lesion depth. The use of GIC alone or incorporating CPP-ACP significantly reduced ∆F compared with other materials. Backscattered SEM images showed no measurable demineralization for enamel treated with either GIC material in contrast with other groups, which showed statistically significant demineralization levels. The fluoride-releasing effects and CPP-ACP benefits of the GIC materials show promise as an effective ESS in inhibiting enamel demineralization adjacent to orthodontic brackets. © 2014 Australian Dental Association.

Fouling on ion-exchange membranes: Classification, characterization and strategies of prevention and control.

Science.gov (United States)

Mikhaylin, Sergey; Bazinet, Laurent

2016-03-01

The environmentally friendly ion-exchange membrane (IEM) processes find more and more applications in the modern industries in order to demineralize, concentrate and modify products. Moreover, these processes may be applied for the energy conversion and storage. However, the main drawback of the IEM processes is a formation of fouling, which significantly decreases the process efficiency and increases the process cost. The present review is dedicated to the problematic of IEM fouling phenomena. Firstly, the major types of IEM fouling such as colloidal fouling, organic fouling, scaling and biofouling are discussed along with consideration of the main factors affecting fouling formation and development. Secondly, the review of the possible methods of IEM fouling characterization is provided. This section includes the methods of fouling visualization and characterization as well as methods allowing investigations of characteristics of the fouled IEMs. Eventually, the reader will find the conventional and modern strategies of prevention and control of different fouling types. Copyright © 2015 Elsevier B.V. All rights reserved.

Glial membranes at the node of Ranvier prevent neurite outgrowth

DEFF Research Database (Denmark)

Huang, Jeffrey K; Phillips, Greg R; Roth, Alejandro D

2005-01-01

of neurite outgrowth, including the oligodendrocyte myelin glycoprotein (OMgp). In rat spinal cord, OMgp was not localized to compact myelin, as previously thought, but to oligodendroglia-like cells, whose processes converge to form a ring that completely encircles the nodes. In OMgp-null mice, CNS nodes......Nodes of Ranvier are regularly placed, nonmyelinated axon segments along myelinated nerves. Here we show that nodal membranes isolated from the central nervous system (CNS) of mammals restricted neurite outgrowth of cultured neurons. Proteomic analysis of these membranes revealed several inhibitors...

An essential primer for understanding the role of topical hemostats, surgical sealants, and adhesives for maintaining hemostasis.

Science.gov (United States)

Gabay, Michael; Boucher, Bradley A

2013-09-01

A wide variety of topical hemostats are approved as adjunctive therapies in the maintenance of hemostasis during surgical procedures in which conventional methods are insufficient or not practical. A multidisciplinary approach to the selection and application of these agents requires input from all members of the surgical team including surgeons, perioperative nurses, blood bank specialists, and pharmacists. However, pharmacist knowledge regarding topical hemostats may be limited based on lack of formal education within college of pharmacy curricula as well as their use being predominantly in the operating room setting. Furthermore, some of these agents might be procured through central supply rather than the hospital pharmacy. Topical hemostats include agents that act as a mechanical barrier to bleeding and provide a physical matrix for clotting, biologically active agents that catalyze coagulation, combination therapies, and synthetic sealants and adhesives. Although many of the topical hemostats were approved for use before the requirement for clinical trials, this review provides an overview of the available clinical evidence regarding the appropriate uses and safety considerations associated with these agents. Proper use of these agents is vital to achieving the best clinical outcomes. Specifically, knowledge of the contraindications and potential adverse events associated with topical hemostats can help prevent unwanted outcomes. Therefore, an understanding of the benefits and potential risks associated with these agents will allow hospital pharmacists to assist in the development and implementation of institutional policies regarding the safe and effective use of hemostatic agents commonly used in the surgical suite. © 2013 Pharmacotherapy Publications, Inc.

AN-69 membrane reactions are pH-dependent and preventable.

Science.gov (United States)

Brophy, P D; Mottes, T A; Kudelka, T L; McBryde, K D; Gardner, J J; Maxvold, N J; Bunchman, T E

2001-07-01

We report two pediatric patients who required blood priming for continuous venovenous hemodiafiltration. Both of these patients developed a significant hypotensive episode with initiation of continuous venovenous hemodiafiltration with immediate resolution on discontinuation. The most notable common characteristics of these patients were the use of the Multi-flo 60 (AN-69) dialyzer membrane and blood priming. No similar episodes were encountered when patients were primed with saline or albumin. The AN-69 membrane is exquisitely pH sensitive. The lower the pH concentration of the blood passing by the membrane, the greater the activation of bradykinin, a known hypotensive-inducing agent, by the dialyzer. On review of blood available from our blood bank, the following parameters became apparent. The pH of standard blood available from our blood bank ranged from 6.1 to 6.4. The blood obtained from our blood bank had significant hyperkalemia, hyponatremia, and hypocalcemia. No reactions were noted when patients were primed with normal saline, which has a pH of around 5.9. We speculate that the presence of endogenous blood substances, such as bradykinin, may have induced the hypotensive episodes. We describe two techniques we developed that should allow for the increased safe and effective use of the AN-69 membranes in continuous venovenous hemodiafiltration circuits. These observations indicate the requirement for careful and close attention to detail when delivering renal replacement therapy to anyone, but especially patients weighing less than 10 kg.

Pencegahan primer pada anak yang berisiko karies tinggi (Primary prevention in children with high caries risk

Directory of Open Access Journals (Sweden)

Ami Angela

2005-09-01

Full Text Available Oral and dental health has got improvement tremendously over the last century but the prevalence of dental caries in children has remained a significant clinical problem. Caries risk varies between individuals according to each subject’s balance between factors exposing to and protecting from caries attack. It is important to assess the risk of caries for all patients on a routine basis. Caries risk is divided into three levels: high, moderate, and low. Thereby, the dental professional is better to make a specific prevention and treatment recommendations to reduce a child risk and improve overall oral health. The goal of caries-risk assessment and preventive treatment is to eliminate caries or at least to reduce the high-caries occurrence down to the level of the remaining part of the age group. Preventive treatment is divided into three parts: primary, secondary, and tertiary prevention. This paper describes the primary prevention in children with high caries risk by behavior modification and tooth protection. Behavior modification is about dental health education, oral hygiene, diet and sugar consumption, sugar-free chewing gum and sugar-free medicines. Tooth protection is about sealant, usage of flouride and chlorhexidine.

Fabricating PFPE Membranes for Capillary Electrophoresis

Science.gov (United States)

Lee, Michael C.; Willis, Peter A.; Greer, Frank; Rolland, Jason

2009-01-01

A process has been developed for fabricating perfluoropolyether (PFPE) membranes that contain microscopic holes of precise sizes at precise locations. The membranes are to be incorporated into laboratory-on-a-chip microfluidic devices to be used in performing capillary electrophoresis. The present process is a modified version of part of the process, described in the immediately preceding article, that includes a step in which a liquid PFPE layer is cured into solid (membrane) form by use of ultraviolet light. In the present process, one exploits the fact that by masking some locations to prevent exposure to ultraviolet light, one can prevent curing of the PFPE in those locations. The uncured PFPE can be washed away from those locations in the subsequent release and cleaning steps. Thus, holes are formed in the membrane in those locations. The most straightforward way to implement the modification is to use, during the ultraviolet-curing step, an ultraviolet photomask similar to the photomasks used in fabricating microelectronic devices. In lieu of such a photomask, one could use a mask made of any patternable ultraviolet-absorbing material (for example, an ink or a photoresist).

ROCK1-directed basement membrane positioning coordinates epithelial tissue polarity.

Science.gov (United States)

Daley, William P; Gervais, Elise M; Centanni, Samuel W; Gulfo, Kathryn M; Nelson, Deirdre A; Larsen, Melinda

2012-01-01

The basement membrane is crucial for epithelial tissue organization and function. However, the mechanisms by which basement membrane is restricted to the basal periphery of epithelial tissues and the basement membrane-mediated signals that regulate coordinated tissue organization are not well defined. Here, we report that Rho kinase (ROCK) controls coordinated tissue organization by restricting basement membrane to the epithelial basal periphery in developing mouse submandibular salivary glands, and that ROCK inhibition results in accumulation of ectopic basement membrane throughout the epithelial compartment. ROCK-regulated restriction of PAR-1b (MARK2) localization in the outer basal epithelial cell layer is required for basement membrane positioning at the tissue periphery. PAR-1b is specifically required for basement membrane deposition, as inhibition of PAR-1b kinase activity prevents basement membrane deposition and disrupts overall tissue organization, and suppression of PAR-1b together with ROCK inhibition prevents interior accumulations of basement membrane. Conversely, ectopic overexpression of wild-type PAR-1b results in ectopic interior basement membrane deposition. Significantly, culture of salivary epithelial cells on exogenous basement membrane rescues epithelial organization in the presence of ROCK1 or PAR-1b inhibition, and this basement membrane-mediated rescue requires functional integrin β1 to maintain epithelial cell-cell adhesions. Taken together, these studies indicate that ROCK1/PAR-1b-dependent regulation of basement membrane placement is required for the coordination of tissue polarity and the elaboration of tissue structure in the developing submandibular salivary gland.

Role of Membrane Biophysics in Alzheimer's - related cell pathways

Directory of Open Access Journals (Sweden)

Donghui eZhu

2015-05-01

Full Text Available Cellular membrane alterations are commonly observed in many diseases, including Alzheimer’s disease (AD. Membrane biophysical properties, such as membrane molecular order, membrane fluidity, organization of lipid rafts, and adhesion between membrane and cytoskeleton, play an important role in various cellular activities and functions. While membrane biophysics impacts a broad range of cellular pathways, this review addresses the role of membrane biophysics in amyloid-β peptide aggregation, Aβ-induced oxidative pathways, amyloid precursor protein processing, and cerebral endothelial functions in AD. Understanding the mechanism(s underlying the effects of cell membrane properties on cellular processes should shed light on the development of new preventive and therapeutic strategies for this devastating disease.

Two Outer Membrane Proteins Contribute to Caulobacter crescentus Cellular Fitness by Preventing Intracellular S-Layer Protein Accumulation

Energy Technology Data Exchange (ETDEWEB)

Overton, K. Wesley; Park, Dan M.; Yung, Mimi C.; Dohnalkova, Alice; Smit, John; Jiao, Yongqin

2016-09-23

Surface layers, or S-layers, are two-dimensional protein arrays that form the outermost layer of many bacteria and archaea. They serve several functions, including physical protection of the cell from environmental threats. The high abundance of S-layer proteins necessitates a highly efficient export mechanism to transport the S-layer protein from the cytoplasm to the cell exterior.Caulobacter crescentusis unique in that it has two homologous, seemingly redundant outer membrane proteins, RsaF_aand RsaF_b, which together with other components form a type I protein translocation pathway for S-layer export. These proteins have homology toEscherichia coliTolC, the outer membrane channel of multidrug efflux pumps. Here we provide evidence that, unlike TolC, RsaF_aand RsaF_bare not involved in either the maintenance of membrane stability or the active export of antimicrobial compounds. Rather, RsaF_aand RsaF_bare required to prevent intracellular accumulation and aggregation of the S-layer protein RsaA; deletion of RsaF_aand RsaF_bled to a general growth defect and lowered cellular fitness. Using Western blotting, transmission electron microscopy, and transcriptome sequencing (RNA-seq), we show that loss of both RsaF_aand RsaF_bled to accumulation of insoluble RsaA in the cytoplasm, which in turn caused upregulation of a number of genes involved in protein misfolding and degradation pathways. These findings provide new insight into the requirement for RsaF_aand RsaF_bin cellular fitness and tolerance to antimicrobial agents and further our understanding of the S-layer export mechanism on both the transcriptional and translational levels in

Acid neutralizing, mechanical and physical properties of pit and fissure sealants containing melt-derived 45S5 bioactive glass.

Science.gov (United States)

Yang, Song-Yi; Piao, Yin-Zhu; Kim, Sung-Min; Lee, Yong-Keun; Kim, Kyoung-Nam; Kim, Kwang-Mahn

2013-12-01

The aim of this study was to examine the effects of 45S5 bioactive glass (BAG) on the acid neutralizing, mechanical and physical properties of pit and fissure sealants. 45S5BAG (glass (180 ± 30 nm) and added into a resin matrix [Bis-GMA/TEGDMA 50/50 (wt%) containing 1% of DMAEMA/CQ 2:1 (wt%)] with varying filler proportions; 0% 45S5BAG+50% glass (BAG0); 12.5% 45S5BAG+37.5% glass (BAG12.5); 25% 45S5BAG+25% glass (BAG25); 37.5% 45S5BAG+12.5% glass (BAG37.5); and 50% 45S5BAG+0% glass (BAG50). To evaluate the acid neutralizing properties, specimens were immersed in lactic acid solution (pH 4.0). Then, the change in pH and the time required to raise the pH from 4.0 to 5.5 were measured. In addition, flexural strength, water sorption and solubility were analyzed. The acid neutralizing properties of each group exhibited increasing pH values as more 45S5BAG was added, and the time required to raise the pH from 4.0 to 5.5 became shorter as the proportion of 45S5BAG increased (P0.05), except for BAG50. The novel pit and fissure sealants neutralized the acid solution (pH 4.0) and exhibited appropriate mechanical and physical properties. Therefore, these compounds are suitable candidates for caries-inhibiting dental materials. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Membrane contactor/separator for an advanced ozone membrane reactor for treatment of recalcitrant organic pollutants in water

International Nuclear Information System (INIS)

Chan, Wai Kit; Jouët, Justine; Heng, Samuel; Yeung, King Lun; Schrotter, Jean-Christophe

2012-01-01

An advanced ozone membrane reactor that synergistically combines membrane distributor for ozone gas, membrane contactor for pollutant adsorption and reaction, and membrane separator for clean water production is described. The membrane reactor represents an order of magnitude improvement over traditional semibatch reactor design and is capable of complete conversion of recalcitrant endocrine disrupting compounds (EDCs) in water at less than three minutes residence time. Coating the membrane contactor with alumina and hydrotalcite (Mg/Al=3) adsorbs and traps the organics in the reaction zone resulting in 30% increase of total organic carbon (TOC) removal. Large surface area coating that diffuses surface charges from adsorbed polar organic molecules is preferred as it reduces membrane polarization that is detrimental to separation. - Graphical abstract: Advanced ozone membrane reactor synergistically combines membrane distributor for ozone, membrane contactor for sorption and reaction and membrane separator for clean water production to achieve an order of magnitude enhancement in treatment performance compared to traditional ozone reactor. Highlights: ► Novel reactor using membranes for ozone distributor, reaction contactor and water separator. ► Designed to achieve an order of magnitude enhancement over traditional reactor. ► Al 2 O 3 and hydrotalcite coatings capture and trap pollutants giving additional 30% TOC removal. ► High surface area coating prevents polarization and improves membrane separation and life.

Membrane fusion and exocytosis.

Science.gov (United States)

Jahn, R; Südhof, T C

1999-01-01

Membrane fusion involves the merger of two phospholipid bilayers in an aqueous environment. In artificial lipid bilayers, fusion proceeds by means of defined transition states, including hourglass-shaped intermediates in which the proximal leaflets of the fusing membranes are merged whereas the distal leaflets are separate (fusion stalk), followed by the reversible opening of small aqueous fusion pores. Fusion of biological membranes requires the action of specific fusion proteins. Best understood are the viral fusion proteins that are responsible for merging the viral with the host cell membrane during infection. These proteins undergo spontaneous and dramatic conformational changes upon activation. In the case of the paradigmatic fusion proteins of the influenza virus and of the human immunodeficiency virus, an amphiphilic fusion peptide is inserted into the target membrane. The protein then reorients itself, thus forcing the fusing membranes together and inducing lipid mixing. Fusion of intracellular membranes in eukaryotic cells involves several protein families including SNAREs, Rab proteins, and Sec1/Munc-18 related proteins (SM-proteins). SNAREs form a novel superfamily of small and mostly membrane-anchored proteins that share a common motif of about 60 amino acids (SNARE motif). SNAREs reversibly assemble into tightly packed helical bundles, the core complexes. Assembly is thought to pull the fusing membranes closely together, thus inducing fusion. SM-proteins comprise a family of soluble proteins that bind to certain types of SNAREs and prevent the formation of core complexes. Rab proteins are GTPases that undergo highly regulated GTP-GDP cycles. In their GTP form, they interact with specific proteins, the effector proteins. Recent evidence suggests that Rab proteins function in the initial membrane contact connecting the fusing membranes but are not involved in the fusion reaction itself.

Wear and superficial roughness of glass ionomer cements used as sealants, after simulated toothbrushing Desgaste e rugosidade superficial de cimentos de ionômero de vidro utilizados como selantes, após escovação simulada

Directory of Open Access Journals (Sweden)

Daniela Rios

2002-12-01

Full Text Available The purpose of this study was to evaluate, in vitro, the properties (wear and roughness of glass ionomer cements that could influence their indication as pit and fissure sealants. The utilized materials were Fuji Plus, Ketac-Molar and Vitremer (in two different proportions: 1:1 and ¼:1. The resin-based sealant Delton was used as control. By means of an electronic balance (precision of 10-4 g, wear was measured in function of weight loss after simulated toothbrushing. Superficial roughness was determined by means of a surface roughness-measuring apparatus. The results revealed that diluted Vitremer and Fuji Plus were less resistant to toothbrushing abrasion and had the greatest increase in superficial roughness.Although in clinical situations luting or diluted ionomer cements are often utilized as alternatives to resin-based sealants, the resultsof this study revealed that the properties of those cements are worse than those of restorative ionomers, whichpresented results similar to those of the evaluated resin sealant.O presente estudo foi conduzido in vitro com o intuito de constatar as propriedades (desgaste e rugosidade dos CIV, as quais influenciam na sua indicação como material selador de fossas e fissuras. Os materiais empregados foram Fuji Plus, Ketac-Molar e Vitremer (duas proporções: 1:1 e ¼:1. O selante Delton foi controle. A determinação do desgaste foi obtida através da quantidade de massa perdida após a escovação e a rugosidade através da análise quantitativa da superfície. Os resultados mostraram que o Vitremer diluído e o Fuji Plus apresentaram maior grau de desgaste e maior aumento de rugosidade. Apesar de clinicamente se encontrar um maior uso dos ionômeros de vidro cimentantes ou diluídos como forma alternativa para material selador; este trabalho permitiu concluir que estes possuem propriedades bastante inferiores quando comparados aos ionômeros restauradores que, por sua vez, possuem resultados semelhantes

Sweeping Gas Membrane Desalination Using Commercial Hydrophobic Hollow Fiber Membranes; TOPICAL

International Nuclear Information System (INIS)

EVANS, LINDSEY; MILLER, JAMES E.

2002-01-01

Water shortages affect 88 developing countries that are home to half of the world's population. In these places, 80-90% of all diseases and 30% of all deaths result from poor water quality. Furthermore, over the next 25 years, the number of people affected by severe water shortages is expected to increase fourfold. Low cost methods of purifying freshwater, and desalting seawater are required to contend with this destabilizing trend. Membrane distillation (MD) is an emerging technology for separations that are traditionally accomplished via conventional distillation or reverse osmosis. As applied to desalination, MD involves the transport of water vapor from a saline solution through the pores of a hydrophobic membrane. In sweeping gas MD, a flowing gas stream is used to flush the water vapor from the permeate side of the membrane, thereby maintaining the vapor pressure gradient necessary for mass transfer. Since liquid does not penetrate the hydrophobic membrane, dissolved ions are completely rejected by the membrane. MD has a number of potential advantages over conventional desalination including low temperature and pressure operation, reduced membrane strength requirements, compact size, and 100% rejection of non-volatiles. The present work evaluated the suitability of commercially available technology for sweeping gas membrane desalination. Evaluations were conducted with Celgard Liqui-Cel(reg s ign) Extra-Flow 2.5X8 membrane contactors with X-30 and X-40 hydrophobic hollow fiber membranes. Our results show that sweeping gas membrane desalination systems are capable of producing low total dissolved solids (TDS) water, typically 10 ppm or less, from seawater, using low grade heat. However, there are several barriers that currently prevent sweeping gas MD from being a viable desalination technology. The primary problem is that large air flows are required to achieve significant water yields, and the costs associated with transporting this air are prohibitive. To

Membrane raft association is a determinant of plasma membrane localization.

Science.gov (United States)

Diaz-Rohrer, Blanca B; Levental, Kandice R; Simons, Kai; Levental, Ilya

2014-06-10

The lipid raft hypothesis proposes lateral domains driven by preferential interactions between sterols, sphingolipids, and specific proteins as a central mechanism for the regulation of membrane structure and function; however, experimental limitations in defining raft composition and properties have prevented unequivocal demonstration of their functional relevance. Here, we establish a quantitative, functional relationship between raft association and subcellular protein sorting. By systematic mutation of the transmembrane and juxtamembrane domains of a model transmembrane protein, linker for activation of T-cells (LAT), we generated a panel of variants possessing a range of raft affinities. These mutations revealed palmitoylation, transmembrane domain length, and transmembrane sequence to be critical determinants of membrane raft association. Moreover, plasma membrane (PM) localization was strictly dependent on raft partitioning across the entire panel of unrelated mutants, suggesting that raft association is necessary and sufficient for PM sorting of LAT. Abrogation of raft partitioning led to mistargeting to late endosomes/lysosomes because of a failure to recycle from early endosomes. These findings identify structural determinants of raft association and validate lipid-driven domain formation as a mechanism for endosomal protein sorting.

Maintenance of membrane organization in the aging mouse brain as the determining factor for preventing receptor dysfunction and for improving response to anti-Alzheimer treatments.

Science.gov (United States)

Colin, Julie; Thomas, Mélanie H; Gregory-Pauron, Lynn; Pinçon, Anthony; Lanhers, Marie-Claire; Corbier, Catherine; Claudepierre, Thomas; Yen, Frances T; Oster, Thierry; Malaplate-Armand, Catherine

2017-06-01

Although a major risk factor for Alzheimer's disease (AD), the "aging" parameter is not systematically considered in preclinical validation of anti-AD drugs. To explore how aging affects neuronal reactivity to anti-AD agents, the ciliary neurotrophic factor (CNTF)-associated pathway was chosen as a model. Comparison of the neuroprotective properties of CNTF in 6- and 18-month old mice revealed that CNTF resistance in the older animals is associated with the exclusion of the CNTF-receptor subunits from rafts and their subsequent dispersion to non-raft cortical membrane domains. This age-dependent membrane remodeling prevented both the formation of active CNTF-receptor complexes and the activation of prosurvival STAT3 and ERK1/2 pathways, demonstrating that age-altered membranes impaired the reactivity of potential therapeutic targets. CNTF-receptor distribution and CNTF signaling responses were improved in older mice receiving dietary docosahexaenoic acid, with CNTF-receptor functionality being similar to those of younger mice, pointing toward dietary intervention as a promising adjuvant strategy to maintain functional neuronal membranes, thus allowing the associated receptors to respond appropriately to anti-AD agents. Copyright © 2017 Elsevier Inc. All rights reserved.

Control of membrane fouling during hyperhaline municipal wastewater treatment using a pilot-scale anoxic/aerobic-membrane bioreactor system

Institute of Scientific and Technical Information of China (English)

Jingmei Sun; Jiangxiu Rong; Lifeng Dai; Baoshan Liu; Wenting Zhu

2011-01-01

Membrane fouling limits the effects of long-term stable operation of membrane bioreactor (MBR).Control of membrane foulin can extend the membrane life and reduce water treatment cost effectively.A pilot scale anoxic/aerobic-membrane bioreactor (A/O MBR,40 L/hr) was used to treat the hyperhaline municipal sewage from a processing zone of Tianjin,China.Impact factors including mixed liquid sludge suspension (MLSS),sludge viscosity (μ),microorganisms,extracellular polymeric substances (EPS),aeration intensity and suction/suspended time on membrane fouling and pollution control were studied.The relationships among various factors associated with membrane fouling were analyzed.Results showed that there was a positive correlation among MLSS,sludge viscosity and trans-membrane pressure (TMP).Considering water treatment efficiency and stable operation of the membrane module,MLSS of 5 g/L was suggested for the process.There was a same trend among EPS,sludge viscosity and TMP.Numbers and species of microorganisms affected membrane fouling.Either too high or too low aeration intensity was not conducive to membrane fouling control.Aeration intensity of 1.0 m3/hr (gas/water ratio of 25:1) is suggested for the process.A long suction time caused a rapid increase in membrane resistance.However,long suspended time cannot prevent the increase of membrane resistance effectively even though a suspended time was necessary for scale off particles from the membrane surface.The suction/suspended time of 12 min/3 min was selected for the process.The interaction of various environmental factors and operation conditions must be considered synthetically.

Prevention of ligneous conjunctivitis by topical and subconjunctival fresh frozen plasma.

Science.gov (United States)

Tabbara, Khalid F

2004-08-01

To present a case of ligneous conjunctivitis where the recurrence of membranous conjunctivitis was prevented by subconjunctival and topical instillation of fresh frozen plasma. Interventional case report. A case of ligneous conjunctivitis with multiple recurrences since the age of 3 years developed recurrent membranous conjunctivitis after transconjunctival levator recession. Blood plasminogen activity was determined. The membrane was excised, and the membrane reappeared 4 days later. The patient was treated with excision of the membrane and subconjunctival injection of fresh frozen plasma and topical fresh frozen plasma. Plasminogen activity of the fresh frozen plasma was normal. Plasminogen blood functional activity was 52% (normal is 80%-120%). The patient had complete remission with no recurrences of membranous conjunctivitis after topical and subconjunctival fresh frozen plasma. Prophylactic use of topical and subconjunctival fresh frozen plasma may help in the prevention of membranes in susceptible patients with plasminogen deficiency.

Membranes as sensitive targets in thymocyte apoptosis

International Nuclear Information System (INIS)

Ramakrishnan, N.; McClain, D.E.; Catravas, G.N.

1993-01-01

The role of cellular membranes in thymocyte apoptosis has been examined. Trolox, a water soluble analogue of vitamin E and inhibitor of membrane damage, inhibits DNA fragmentation in thymocytes exposed to γ-radiation, and is most effective in inhibiting DNA fragmentation when added to cells within 30 min post-irradiation. Exposure to trolox only during irradiation did not prevent DNA fragmentation. Incubation of the irradiated cell suspension with trolox for 2h post-irradiation was sufficient to prevent DNA fragmentation measured at 24 h in irradiated cells, suggesting that trolox irreversibly inhibits a cellular lesion required for apoptosis. The induction of DNA fragmentation appears to be related to a concurrent, pronounced flow of Ca 2+ into the cell. At 3 h post-irradiation the amount of Ca 2+ in irradiated thymocytes was more than twice that of unirradiated thymocytes. Trolox treatment completely blocked the radiation-induced influx of Ca 2+ into the thymocytes. These results suggest that membrane damage is a critical lesion involved in DNA fragmentation in thymocyte apoptosis. (author)

Ceramic membrane defouling (cleaning) by air Nano Bubbles.

Science.gov (United States)

Ghadimkhani, Aliasghar; Zhang, Wen; Marhaba, Taha

2016-03-01

Ceramic membranes are among the most promising technologies for membrane applications, owing to their excellent resistance to mechanical, chemical, and thermal stresses. However, membrane fouling is still an issue that hampers the applications at large scales. Air Nano Bubbles (NBs), due to high mass transfer efficiency, could potentially prevent fouling of ceramic membrane filtration processes. In this study, bench and pilot scale ceramic membrane filtration was performed with air NBs to resist fouling. To simulate fouling, humic acid, as an organic foulant, was applied to the membrane flat sheet surface. Complete membrane clogging was achieved in less than 6 h. Membrane defouling (cleaning) was performed by directly feeding of air NBs to the membrane cells. The surface of the ceramic membrane was superbly cleaned by air NBs, as revealed by atomic force microscope (AFM) images before and after the treatment. The permeate flux recovered to its initial level (e.g., 26.7 × 10(-9) m(3)/m(2)/s at applied pressure of 275.8 kPa), which indicated that NBs successfully unclogged the pores of the membrane. The integrated ceramic membrane and air NBs system holds potential as an innovative sustainable technology. Copyright © 2015 Elsevier Ltd. All rights reserved.

Retention and penetration of a conventional resin-based sealant and a photochromatic flowable composite resin placed on occlusal pits and fissures

Directory of Open Access Journals (Sweden)

Aguilar F

2007-01-01

Full Text Available This study compares the retention and penetration of a conventional resin-based sealant (Fluroshield and a photochromatic flowable composite resin (Tetric Flow Chroma placed on occlusal pits and fissures and submitted to thermal or chemical cycling regimens. Penetration assessment - ten premolars were sealed with each material, isolated (except for the sealed surface and immersed in 0.2% Rhodamine B. The teeth were serially sectioned in a mesiodistal direction. The images of the sections were digitized and analyzed (ImageLab. The distance between the most superficial and the deepest points on the occlusal central groove was calculated to determine the groove′s total depth. The length of the central groove filled with the sealant was divided by its total depth to obtain the percentage of sealing of the occlusal groove. Retention assessment - 30 premolars were sealed, their occlusal surfaces were photographed and the area occupied by the sealing materials was demarcated (ImageLab. The teeth were submitted to different treatments: thermocycled, stored in artificial saliva and immersed in acetic acid and saliva (10 cycles/day protocol for 30 days. New photographs were taken to assess the final area occupied by the materials. The difference between the final and initial area was calculated to obtain the material loss. The data was analyzed (two-way anova and Tukey′s test P < 0.05. Both materials presented similar penetration of the occlusal central groove. After thermal and chemical cycling, the materials did not differ with respect to retention, except for immersion in acetic acid. In this case, Tetric Flow Chroma presented greater retention than Fluoroshield.

Measurement of properties of sealant materials for solid oxide fuel cell systems

International Nuclear Information System (INIS)

Boersma, R.J.; Sammes, N.M.; Zhang, Y.

1998-01-01

Thermal expansion of ceramic materials, ceramic cements and steels was studied, and their compatibility with materials used in the SOFC system was evaluated. A number of ceramic cements, a glass paste and a glass ceramic were examined to identify their potential as a sealing material in a tubular fuel cell system. Thermal expansion coefficients of these materials were compared for thermal matching with materials employed in the fuel cell construction, such as yttria stabilised with 8 mole% zirconia (8YSZ) and stainless steel. A reasonable match was found for Macor, a glass ceramic, with one of the steel samples studied and with 8YSZ. Candidate sealants were tested for bonding quality, which made it evident that the ceramic cements had to be discarded. Good bonds between Macor and one of the steel samples and Macor and 8YSZ were formed, resulting in a gas tight seal. Uncertainty remains regarding the long term effect of the interface reactions between steel and Macor. Exposure of the Macor and a steel-Macor-8YSZ assembly to the different fuel cell gas atmospheres revealed that the Macor reacts with hydrogen, the long term effect of which is also unknown. Copyright (1998) Australasian Ceramic Society

Prevention and treatment of white spot lesions in orthodontic patients

Directory of Open Access Journals (Sweden)

Maryam Khoroushi

2017-01-01

Full Text Available Decalcification of enamel, appearing as white spot lesions (WSLs, around fixed orthodontic appliances is a major challenge during and after fixed orthodontic treatment by considering the fact that the goal of orthodontic treatment is to enhance facial and dental esthetic appearance. Banded or bonded teeth exhibit a significantly higher rate of WSLs compared to the controls with no braces as fixed appliances and the bonding materials promote retention of biofilms. These lesions are managed in the first step by establishing good oral hygiene habits and prophylaxis with topical fluorides, including high-fluoride toothpastes, fluoride mouthwashes, gels, varnishes, fluoride-containing bonding materials, and elastic ligatures. Recently, other materials and methods have been recommended, including the application of casein phosphopeptides-amorphous calcium phosphate, antiseptics, probiotics, polyols, sealants, laser, tooth bleaching agents, resin infiltration, and microabrasion. This article reviews the currently used methods to manage enamel demineralization during and after orthodontic treatment and the risk factors and preventive measures based on the latest evidence.

Dynamic coating of mf/uf membranes for fouling mitigation

KAUST Repository

Tabatabai, S. Assiyeh Alizadeh

2017-01-19

A membrane system including an anti-fouling layer and a method of applying an anti-fouling layer to a membrane surface are provided. In an embodiment, the surface is a microfiltration (MF) or an ultrafiltration (UF) membrane surface. The anti-fouling layer can include a stimuli responsive layer and a dynamic protective layer applied over the stimuli responsive layer that can be a coating on a surface of the membrane. The stimuli responsive polymer layer can act as an adhesive prior to coating with the dynamic protective layer to aid in adhering the dynamic protective layer to the membrane surface. The dynamic protective layer can be formed by suitable nanoparticles that can prevent adhesion of foulants directly to the membrane surface. The stimuli responsive layer can be responsive to physio- chemical stimuli to cause a release of the stimuli responsive layer and the dynamic protective layer including foulants from the membrane.

Comparison between moving bed-membrane bioreactor (MB-MBR) and membrane bioreactor (MBR) systems: influence of wastewater salinity variation.

Science.gov (United States)

Di Trapani, Daniele; Di Bella, Gaetano; Mannina, Giorgio; Torregrossa, Michele; Viviani, Gaspare

2014-06-01

Two pilot plant systems were investigated for the treatment of wastewater subject to a gradual increase of salinity. In particular, a membrane bioreactor (MBR) and a moving bed biofilm membrane bioreactor (MB-MBR) were analyzed. Carbon and ammonium removal, kinetic constants and membranes fouling rates have been assessed. Both plants showed very high efficiency in terms of carbon and ammonium removal and the gradual salinity increase led to a good acclimation of the biomass, as confirmed by the respirometric tests. Significant biofilm detachments from carriers were experienced, which contributed to increase the irreversible superficial cake deposition. However, this aspect prevented the pore fouling tendency in the membrane module of MB-MBR system. On the contrary, the MBR pilot, even showing a lower irreversible cake deposition, was characterized by a higher pore fouling tendency. Copyright © 2014 Elsevier Ltd. All rights reserved.

Atraumatic restorative treatment and minimal intervention dentistry.

Science.gov (United States)

Frencken, J E

2017-08-11

Too many people worldwide suffer from the consequences of untreated dentine carious lesions. This finding reflects the inability of the currently used traditional mode of treatments to manage such lesions. A change is needed. Dental training institutions should depart from the traditional 'drill and fill' treatments and embrace the holistic oral healthcare approach that is minimal intervention dentistry (MID) and includes within it minimally invasive operative skills. Dental caries is, after all, a preventable disease. The atraumatic restorative treatment (ART) concept is an example of MID. ART consists of a preventive (ART sealant) and a restorative (ART restoration) component. ART sealants using high-viscosity glass-ionomer (HVGIC) have a very high dentine carious lesion preventive effect. The survival rate of these sealants is not significantly different from that of sealants produced with resin. The survival rate of ART/HVGIC restorations matches those of amalgam and resin composite in single- and multiple-surface cavities in primary teeth and in single-surface cavities in permanent teeth. The principles of carious tissue removal within a cavity recommended by the International Caries Consensus Collaboration are in line with those of treating a cavity using ART. Owing to its good performance and the low levels of discomfort/pain and dental anxiety associated with it, ART and/or other evidence-based atraumatic care procedures should be the first treatment for a primary dentine carious lesion. Only if the use of ART is not indicated should other more invasive and less-atraumatic care procedures be used in both primary and permanent dentitions.

Importance of balancing membrane and electrode water in anion exchange membrane fuel cells

Science.gov (United States)

Omasta, T. J.; Wang, L.; Peng, X.; Lewis, C. A.; Varcoe, J. R.; Mustain, W. E.

2018-01-01

Anion exchange membrane fuel cells (AEMFCs) offer several potential advantages over proton exchange membrane fuel cells (PEMFCs), most notably to overcome the cost barrier that has slowed the growth and large scale implementation of fuel cells for transportation. However, limitations in performance have held back AEMFCs, specifically in the areas of stability, carbonation, and maximum achievable current and power densities. In order for AEMFCs to contend with PEMFCs for market viability, it is necessary to realize a competitive cell performance. This work demonstrates a new benchmark for a H2/O2 AEMFC with a peak power density of 1.4 W cm-2 at 60 °C. This was accomplished by taking a more precise look at balancing necessary membrane hydration while preventing electrode flooding, which somewhat surprisingly can occur both at the anode and the cathode. Specifically, radiation-grafted ETFE-based anion exchange membranes and anion exchange ionomer powder, functionalized with benchmark benzyltrimethylammonium groups, were utilized to examine the effects of the following parameters on AEMFC performance: feed gas flow rate, the use of hydrophobic vs. hydrophilic gas diffusion layers, and gas feed dew points.

Research and development of lithium isotope separation using an ionic-liquid impregnated organic membrane

International Nuclear Information System (INIS)

Hoshino, Tsuyoshi

2013-01-01

The tritium needed as a fuel for fusion reactors is produced by the neutron capture reaction of lithium-6 ( 6 Li) in tritium breeding materials. However, natural Li contains only about 7.6 at.% 6 Li. In Japan, new lithium isotope separation technique using ionic-liquid impregnated organic membranes have been developed. The improvement in the durability of the ionic-liquid impregnated organic membrane is one of the main issues for stable, long-term operation of electrodialysis cells while maintaining good performance. Therefore, we developed highly-durable ionic-liquid impregnated organic membrane. Both ends of the ionic-liquid impregnated organic membrane were covered by a nafion 324 overcoat to prevent the outflow of the ionic liquid. The transmission of Lithium aqueous solution after 10 hours under the highly-durable ionic-liquid impregnated organic membrane is almost 13%. So this highly-durable ionic-liquid impregnated organic membrane for long operating of electrodialysis cells has been developed through successful prevention of ion liquid dissolution. (J.P.N.)

Comparison of six different methods of cleaning and preparing occlusal fissure surface before placement of pit and fissure sealant: An in vitro study

Directory of Open Access Journals (Sweden)

A Agrawal

2012-01-01

Full Text Available Aim & Objectives : The purpose of this in vitro study was to evaluate and compare the microleakage of pit and fissure sealants after using six different preparation techniques: (a brush, (b pumice slurry application, (c bur, (d air polishing, (e air abrasion, and (f longer etching time. Material & Method : The study was conducted on 60 caries-free first premolars extracted for orthodontic purpose. These teeth were randomly assigned to six groups of 10 teeth each. Teeth were prepared using one of six occlusal surface treatments prior to placement of Clinpro" 3M ESPE light-cured sealant. The teeth were thermocycled for 500 cycles and stored in 0.9% normal saline. Teeth were sealed apically and coated with nail varnish 1 mm from the margin and stained in 1% methylene blue for 24 hours. Each tooth was divided buccolingually parallel to the long axis of the tooth, yielding two sections per tooth for analysis. The surfaces were scored from 0 to 2 for the extent of microleakage. Statistical Analysis : Results obtained for microleakage were analyzed by using t-tests at sectional level and chi-square test and analysis of variance (ANOVA at the group level. Results : The results of round bur group were significantly superior when compared to all other groups. The application of air polishing and air abrasion showed better results than pumice slurry, bristle brush, and longer etching time. Round bur group was the most successful cleaning and preparing technique. Air polishing and air abrasion produced significantly less microleakage than traditional pumice slurry, bristle brush, and longer etching time.

Microfluidic devices for investigation of biomimetic membranes for sensor and separation applications

DEFF Research Database (Denmark)

Pszon-Bartosz, Kamila Justyna

to microfluidic designs involving protein delivery to biomimetic membranes developed for sensor and separation applications. Finally, an OMP functionality modulation with β-cyclodextrin (β-CD) was shown and revealed the protein potential application as a sensor. Moreover, the β-CD blocker may be used to prevent...... for industrial applications. Among them are the inherent fragility of lipid membranes, the challenge of up-scaling the effective membrane area and the quantification of the protein delivery to the lipid membrane which may determined the biomimetic membrane application. This PhD thesis addresses the above...

Modification of radiation-induced oxidative damage in liposomal and microsomal membrane by eugenol

Energy Technology Data Exchange (ETDEWEB)

Pandey, B.N. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Lathika, K.M. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Mishra, K.P. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)]. E-mail: kpm@magnum.barc.ernet.in

2006-03-15

Radiation-induced membrane oxidative damage, and their modification by eugenol, a natural antioxidant, was investigated in liposomes and microsomes. Liposomes prepared with DPH showed decrease in fluorescence after {gamma}-irradiation, which was prevented significantly by eugenol and correlated with magnitude of oxidation of phospholipids. Presence of eugenol resulted in substantial inhibition in MDA formation in irradiated liposomes/microsomes, which was less effective when added after irradiation. Similarly, the increase in phospholipase C activity observed after irradiation in microsomes was inhibited in samples pre-treated with eugenol. Results suggest association of radio- oxidative membrane damage with alterations in signaling molecules, and eugenol significantly prevented these membrane damaging events.

Flux flow and cleaning enhancement in a spiral membrane element ...

African Journals Online (AJOL)

The effect of backpulsing, into the permeate space of a 2.5 inch spiral wrap membrane, on the prevention of fouling (flux enhancement) was investigated experimentally. These experiments were performed using a 500 mg∙ℓ-1 dextrin solution and a 100 000 MCWO polypropylene membrane, with a feed pressure of 100 kPa ...

MEMBRANE BIOREACTOR FOR TREATMENT OF RECALCITRANT WASTEWATERS

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Suprihatin Suprihatin

2012-02-01

Full Text Available The low biodegradable wastewaters remain a challenge in wastewater treatment technology. The performance of membrane bioreactor systems with submerged hollow fiber micro- and ultrafiltration membrane modules were examined for purifying recalcitrant wastewaters of leachate of a municipal solid waste open dumping site and effluent of pulp and paper mill. The use of MF and UF membrane bioreactor systems showed an efficient treatment for both types wastewaters with COD reduction of 80-90%. The membrane process achieved the desirable effects of maintaining reasonably high biomass concentration and long sludge retention time, while producing a colloid or particle free effluent. For pulp and paper mill effluent a specific sludge production of 0.11 kg MLSS/kg COD removed was achieved. A permeate flux of about 5 L/m²h could be achieved with the submerged microfiltration membrane. Experiments using ultrafiltration membrane produced relatively low permeate fluxes of 2 L/m²h. By applying periodical backwash, the flux could be improved significantly. It was indicated that the particle or colloid deposition on membrane surface was suppressed by backwash, but reformation of deposit was not effectively be prevented by shear-rate effect of aeration. Particle and colloid started to accumulate soon after backwash. Construction of membrane module and operation mode played a critical role in achieving the effectiveness of aeration in minimizing deposit formation on the membrane surface.

Flunarizine Prevents Hepatitis C Virus Membrane Fusion in a Genotype-dependent Manner by Targeting the Potential Fusion Peptide within E1

Science.gov (United States)

Perin, Paula M.; Haid, Sibylle; Brown, Richard J. P.; Doerrbecker, Juliane; Schulze, Kai; Zeilinger, Carsten; von Schaewen, Markus; Heller, Brigitte; Vercauteren, Koen; Luxenburger, Eva; Baktash, Yasmine M.; Vondran, Florian W. R.; Speerstra, Sietkse; Awadh, Abdullah; Mukhtarov, Furkat; Schang, Luis M; Kirschning, Andreas; Müller, Rolf; Guzman, Carlos A.; Kaderali, Lars; Randall, Glenn; Meuleman, Philip; Ploss, Alexander; Pietschmann, Thomas

2015-01-01

To explore mechanisms of hepatitis C virus (HCV) replication we screened a compound library including licensed drugs. Flunarizine, a diphenylmethylpiperazine used to treat migraine, inhibited HCV cell entry in vitro and in vivo in a genotype-dependent fashion. Analysis of mosaic viruses between susceptible and resistant strains revealed that E1 and E2 glycoproteins confer susceptibility to flunarizine. Time of addition experiments and single particle tracking of HCV demonstrated that flunarizine specifically prevents membrane fusion. Related phenothiazines and pimozide also inhibited HCV infection and preferentially targeted HCV genotype 2 viruses. However, phenothiazines and pimozide exhibited improved genotype coverage including the difficult to treat genotype 3. Flunarizine-resistant HCV carried mutations within the alleged fusion peptide and displayed cross-resistance to these compounds, indicating that these drugs have a common mode of action. Conclusion: These observations reveal novel details about HCV membrane fusion. Moreover, flunarizine and related compounds represent first-in-class HCV fusion inhibitors that merit consideration for repurposing as cost-effective component of HCV combination therapies. PMID:26248546

The efficiency and safety of fibrin sealant for reducing blood loss in primary total hip arthroplasty: A systematic review and meta-analysis.

Science.gov (United States)

Wang, Zhiyuan; Xiao, Lin; Guo, Hao; Zhao, Guanghui; Ma, Jianbing

2017-01-01

Total hip arthroplasty (THA) is associated with substantial blood loss. The objective of present systematic review and meta-analysis is to provide evidence from randomized controlled trials (RCTs) on the efficiency and safety of administration of fibrin sealant (FS) for reducing blood loss in patients undergoing primary THA. Potential relevant studies were identified from electronic databases including Medline, PubMed, Embase, ScienceDirect, web of science and Cochrane Library. Gray academic studies were also identified from the reference list of included studies. There was no language restriction. Pooling of data was carried out by using RevMan 5.1. Six randomized controlled trials (RCTs) met the inclusion criteria. Current meta-analysis indicated that there were significant differences in terms of total blood loss (MD = -153.77, 95% CI: -287.21 to -20.34, P = 0.02), postoperative hemoglobin level (MD = -0.25, 95% CI: -0.46 to -0.05, P = 0.02) and transfusion rate (RD = -0.12, 95% CI: -0.22 to -0.03, P = 0.01) between groups. No significant differences were found regarding the incidence of deep venous thrombosis (DVT) (RD = 0.00, 95% CI: -0.01to 0.01, P = 0.51) or other side effects. Administration of fibrin sealant in total hip arthroplasty may reduce total blood loss, postoperative hemoglobin decline and transfusion requirements. Moreover, no adverse effect was related to FS. Due to the limited quality of the evidence currently available, higher quality RCTs are required. Copyright © 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

Microfluidic rectifier based on poly(dimethylsiloxane) membrane and its application to a micropump.

Science.gov (United States)

Wang, Yao-Nan; Tsai, Chien-Hsiung; Fu, Lung-Ming; Lin Liou, Lung-Kai

2013-01-01

A microfluidic rectifier incorporating an obstructed microchannel and a PDMS membrane is proposed. During forward flow, the membrane deflects in the upward direction; thereby allowing the fluid to pass over the obstacle. Conversely, during reverse flow, the membrane seals against the obstacle, thereby closing the channel and preventing flow. It is shown that the proposed device can operate over a wide pressure range by increasing or decreasing the membrane thickness as required. A microfluidic pump is realized by integrating the rectifier with a simple stepper motor mechanism. The experimental results show that the pump can achieve a vertical left height of more than 2 m. Moreover, it is shown that a maximum flow rate of 6.3 ml/min can be obtained given a membrane thickness of 200 μm and a motor velocity of 80 rpm. In other words, the proposed microfluidic rectifier not only provides an effective means of preventing reverse flow but also permits the realization of a highly efficient microfluidic pump.

A plasma membrane localization signal in the HIV-1 envelope cytoplasmic domain prevents localization at sites of vesicular stomatitis virus budding and incorporation into VSV virions.

Science.gov (United States)

Johnson, J E; Rodgers, W; Rose, J K

1998-11-25

Previous studies showed that the HIV-1 envelope (Env) protein was not incorporated into vesicular stomatitis virus (VSV) virions unless its cytoplasmic tail was replaced with that of the VSV glycoprotein (G). To determine whether the G tail provided a positive incorporation signal for Env, or if sequences in the Env tail prevented incorporation, we generated mutants of Env with its 150-amino-acid tail shortened to 29, 10, or 3 amino acids (Envtr mutants). Cells infected with VSV recombinants expressing these proteins or an Env-G tail hybrid showed similar amounts of Env protein at the surface. The Env-G tail hybrid or the Envtr3 mutant were incorporated at the highest levels into budding VSV virions. In contrast, the Envtr29 or Envtr10 mutants were incorporated poorly. These results defined a signal preventing incorporation within the 10 membrane-proximal amino acids of the Env tail. Confocal microscopy revealed that this signal functioned by causing localization of human immunodeficiency virus type 1 Env to plasma membrane domains distinct from the VSV budding sites, where VSV proteins were concentrated. Copyright 1998 Academic Press.

Bcl-xL regulates mitochondrial energetics by stabilizing the inner membrane potential.

Science.gov (United States)

Chen, Ying-Bei; Aon, Miguel A; Hsu, Yi-Te; Soane, Lucian; Teng, Xinchen; McCaffery, J Michael; Cheng, Wen-Chih; Qi, Bing; Li, Hongmei; Alavian, Kambiz N; Dayhoff-Brannigan, Margaret; Zou, Shifa; Pineda, Fernando J; O'Rourke, Brian; Ko, Young H; Pedersen, Peter L; Kaczmarek, Leonard K; Jonas, Elizabeth A; Hardwick, J Marie

2011-10-17

Mammalian Bcl-x(L) protein localizes to the outer mitochondrial membrane, where it inhibits apoptosis by binding Bax and inhibiting Bax-induced outer membrane permeabilization. Contrary to expectation, we found by electron microscopy and biochemical approaches that endogenous Bcl-x(L) also localized to inner mitochondrial cristae. Two-photon microscopy of cultured neurons revealed large fluctuations in inner mitochondrial membrane potential when Bcl-x(L) was genetically deleted or pharmacologically inhibited, indicating increased total ion flux into and out of mitochondria. Computational, biochemical, and genetic evidence indicated that Bcl-x(L) reduces futile ion flux across the inner mitochondrial membrane to prevent a wasteful drain on cellular resources, thereby preventing an energetic crisis during stress. Given that F(1)F(O)-ATP synthase directly affects mitochondrial membrane potential and having identified the mitochondrial ATP synthase β subunit in a screen for Bcl-x(L)-binding partners, we tested and found that Bcl-x(L) failed to protect β subunit-deficient yeast. Thus, by bolstering mitochondrial energetic capacity, Bcl-x(L) may contribute importantly to cell survival independently of other Bcl-2 family proteins.

Drug loaded homogeneous electrospun PCL/gelatin hybrid nanofiber structures for anti-infective tissue regeneration membranes.

Science.gov (United States)

Xue, Jiajia; He, Min; Liu, Hao; Niu, Yuzhao; Crawford, Aileen; Coates, Phil D; Chen, Dafu; Shi, Rui; Zhang, Liqun

2014-11-01

Infection is the major reason for guided tissue regeneration/guided bone regeneration (GTR/GBR) membrane failure in clinical application. In this work, we developed GTR/GBR membranes with localized drug delivery function to prevent infection by electrospinning of poly(ε-caprolactone) (PCL) and gelatin blended with metronidazole (MNA). Acetic acid (HAc) was introduced to improve the miscibility of PCL and gelatin to fabricate homogeneous hybrid nanofiber membranes. The effects of the addition of HAc and the MNA content (0, 1, 5, 10, 20, 30, and 40 wt.% of polymer) on the properties of the membranes were investigated. The membranes showed good mechanical properties, appropriate biodegradation rate and barrier function. The controlled and sustained release of MNA from the membranes significantly prevented the colonization of anaerobic bacteria. Cells could adhere to and proliferate on the membranes without cytotoxicity until the MNA content reached 30%. Subcutaneous implantation in rabbits for 8 months demonstrated that MNA-loaded membranes evoked a less severe inflammatory response depending on the dose of MNA than bare membranes. The biodegradation time of the membranes was appropriate for tissue regeneration. These results indicated the potential for using MNA-loaded PCL/gelatin electrospun membranes as anti-infective GTR/GBR membranes to optimize clinical application of GTR/GBR strategies. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Analysis of activities of the preventive dentistry service in the Health Area 8 of the Valencia Autonomous Region].

Science.gov (United States)

Llena Puy, M C; Ausina Márquez, V

1996-02-29

We describe and analize the activities we carried out in a surgery from a preventive dentistry unit. Longitudinal descriptive study from 1993 since 1994. Health Area 8 from the Valencian Autonomous Region. Children from 3 to 14 year-old attendant to the preventive dentistry unit's surgery (2.497). We visited 5.012 children. The highest percentage of population corresponded to the zona 4, where began at first the preventive service. The activities distribution was as follow: oral explorations and plaque control (100%), fluoride topic aplication (90.38%), diet control (36.81%), pit and fisure sealants (6.46%), profilaxis (8.71%), radiological diagnosis (6.46%), dental emergencies (2.17%). The users origin was: 38.88% school oral explorations made over 6- and 10-year-old children; 63.71% from self-request; and 16.45% sent by other health professionals. 41.42% were continuated visits. Demand of preventive dental services is very high in our health area, although incorporation of therapeutic techniques is wished by the population. This demand increase as well as the surgery is closer to the user. People from big cities are stubborn using these services from smallest villages, even having transport facilities. Children start coming to the consults between 5-6 year-old, keeping an acceptable control until 12 approximately.

Membranes for Redox Flow Battery Applications

Science.gov (United States)

Prifti, Helen; Parasuraman, Aishwarya; Winardi, Suminto; Lim, Tuti Mariana; Skyllas-Kazacos, Maria

2012-01-01

The need for large scale energy storage has become a priority to integrate renewable energy sources into the electricity grid. Redox flow batteries are considered the best option to store electricity from medium to large scale applications. However, the current high cost of redox flow batteries impedes the wide spread adoption of this technology. The membrane is a critical component of redox flow batteries as it determines the performance as well as the economic viability of the batteries. The membrane acts as a separator to prevent cross-mixing of the positive and negative electrolytes, while still allowing the transport of ions to complete the circuit during the passage of current. An ideal membrane should have high ionic conductivity, low water intake and excellent chemical and thermal stability as well as good ionic exchange capacity. Developing a low cost, chemically stable membrane for redox flow cell batteries has been a major focus for many groups around the world in recent years. This paper reviews the research work on membranes for redox flow batteries, in particular for the all-vanadium redox flow battery which has received the most attention. PMID:24958177

Membranes for redox flow battery applications.

Science.gov (United States)

Prifti, Helen; Parasuraman, Aishwarya; Winardi, Suminto; Lim, Tuti Mariana; Skyllas-Kazacos, Maria

2012-06-19

The need for large scale energy storage has become a priority to integrate renewable energy sources into the electricity grid. Redox flow batteries are considered the best option to store electricity from medium to large scale applications. However, the current high cost of redox flow batteries impedes the wide spread adoption of this technology. The membrane is a critical component of redox flow batteries as it determines the performance as well as the economic viability of the batteries. The membrane acts as a separator to prevent cross-mixing of the positive and negative electrolytes, while still allowing the transport of ions to complete the circuit during the passage of current. An ideal membrane should have high ionic conductivity, low water intake and excellent chemical and thermal stability as well as good ionic exchange capacity. Developing a low cost, chemically stable membrane for redox flow cell batteries has been a major focus for many groups around the world in recent years. This paper reviews the research work on membranes for redox flow batteries, in particular for the all-vanadium redox flow battery which has received the most attention.

Membranes for Redox Flow Battery Applications

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Maria Skyllas-Kazacos

2012-06-01

Full Text Available The need for large scale energy storage has become a priority to integrate renewable energy sources into the electricity grid. Redox flow batteries are considered the best option to store electricity from medium to large scale applications. However, the current high cost of redox flow batteries impedes the wide spread adoption of this technology. The membrane is a critical component of redox flow batteries as it determines the performance as well as the economic viability of the batteries. The membrane acts as a separator to prevent cross-mixing of the positive and negative electrolytes, while still allowing the transport of ions to complete the circuit during the passage of current. An ideal membrane should have high ionic conductivity, low water intake and excellent chemical and thermal stability as well as good ionic exchange capacity. Developing a low cost, chemically stable membrane for redox flow cell batteries has been a major focus for many groups around the world in recent years. This paper reviews the research work on membranes for redox flow batteries, in particular for the all-vanadium redox flow battery which has received the most attention.

Aqua-vanadyl ion interaction with Nafion® membranes

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Vijayakumar eMurugesan

2015-03-01

Full Text Available Lack of comprehensive understanding about the interactions between Nafion membrane and battery electrolytes prevents the straightforward tailoring of optimal materials for redox flow battery applications. In this work, we analyzed the interaction between aqua-vanadyl cation and sulfonic sites within the pores of Nafion membranes using combined theoretical and experimental X-ray spectroscopic methods. Molecular level interactions namely solvent share and contact pair mechanisms are discussed based on Vanadium and Sulfur K-edge spectroscopic analysis.

Preventing Advanced Carious Lesions with Caries Atraumatic Restorative Technique.

Science.gov (United States)

Byrd, Tammi O

2016-06-01

An alternative approach to controlling dental caries and preventing the associated pain, called atraumatic restorative technique (ART), is described for populations in need, where dental hygienists restore decayed teeth with glass ionomer restorations without prior removal of all decayed tooth structure. There are populations whose decay needs are not adequately being met within the current oral health care delivery system. These include those in poverty conditions, vulnerable children, and the elderly who are often in long-term care facilities without adequate resources or opportunities for traditional dentistry. ART provides a viable option for controlling caries and relieving the pain of untreated decay. The purpose of this article is to suggest that the evidence surrounding ART be viewed objectively and that dental hygienists, with additional education in this approach, can contribute to relieving the pain of untreated dental decay. Evidence suggests that teeth can be effectively restored with ART. Dental hygienists represent an appropriate workforce to provide ART with their current background and education combined plus a brief training program; it is suggested that dental hygiene educational programs include ART within the curriculum. Along with dental sealants and fluoride varnish application, ART can be an important component of a comprehensive preventive program to address the unmet needs of vulnerable populations. Copyright © 2016 Elsevier Inc. All rights reserved.

[Prevention and management of postresectional bronchopleural fistula].

Science.gov (United States)

Ishikawa, Shigemi

2008-07-01

Bronchopleural fistula (BPF) is still a life-threatening complication after pulmonary resection. Several factors were identified to contribute BPF. Meticulous surgical technique and the liberal use of prophylactic, pedicled flaps are important for prevention. Although these patients often present compromised and moribund, evaluation and management should proceed in a logical, stepwise fashion. In high-risk surgical patients, bronchoscopic procedures using different glues and sealants may serve as a temporary bridge until the patient's recovery or as a permanent resolution. However persistent conservative therapy may deteriorate patient's condition. Immediate creation of open window thoracotomy has been shown to be a significant predictor of wound closure afterwards. Pedicled muscle or omental flaps are useful to close bronchial stump and to fill the residual space in the thorax after pulmonary resection. Once fistula closed, the pleural space is filled with an antibiotic solution and then the open window thoracotomy closed in layers as Clagett procedure. The transternal transpericardial approach to recalcitrant postpneumonectomy BPF can be considered when patients have failed prior closure attempt. To conclude, survival and excellent result of BPF depends on early diagnosis, and aggressive surgical intervention.

Reconciliation of opposing views on membrane-sugar interactions

DEFF Research Database (Denmark)

Andersen, Heidi D.; Wang, Chunhua; Arleth, Lise

2011-01-01

It is well established that small sugars exert different types of stabilization of biomembranes both in vivo and in vitro. However, the essential question of whether sugars are bound to or expelled from membrane surfaces, i.e., the sign and size of the free energy of the interaction, remains...... unresolved, and this prevents a molecular understanding of the stabilizing mechanism. We have used small-angle neutron scattering and thermodynamic measurements to show that sugars may be either bound or expelled depending on the concentration of sugar. At low concentration, small sugars bind quite strongly...... to a lipid bilayer, and the accumulation of sugar at the interface makes the membrane thinner and laterally expanded. Above â¼0.2 M the sugars gradually become expelled from the membrane surface, and this repulsive mode of interaction counteracts membrane thinning. The dual nature of sugar...

Organic-inorganic membranes for filtration of corn distillery

Directory of Open Access Journals (Sweden)

Myronchuk Valeriy G.

2016-01-01

Full Text Available Organic-inorganic membranes were obtained by modification of polymer microfiltration membrane with inorganic ion-exchangers, which form secondary porosity inside macroporous substrate (zirconium hydrophosphate or simultaneously in the macroporous substrate and active layer, depending of the particle size (from ≈50 nm up to several microns. Precipitation of the inorganic constituent is considered from the point of view of Ostwald-Freundlich equation. Such processes as pressing test in deionized water and filtration of corn distillery at 1-6 bar were investigated. Theoretical model allowing to establish fouling mechanism, was applied. It was found that the particles both in the substrate and active layer prevent fouling of the membrane with organics and provide rejection of colloidal particles.

At the border: the plasma membrane-cell wall continuum.

Science.gov (United States)

Liu, Zengyu; Persson, Staffan; Sánchez-Rodríguez, Clara

2015-03-01

Plant cells rely on their cell walls for directed growth and environmental adaptation. Synthesis and remodelling of the cell walls are membrane-related processes. During cell growth and exposure to external stimuli, there is a constant exchange of lipids, proteins, and other cell wall components between the cytosol and the plasma membrane/apoplast. This exchange of material and the localization of cell wall proteins at certain spots in the plasma membrane seem to rely on a particular membrane composition. In addition, sensors at the plasma membrane detect changes in the cell wall architecture, and activate cytoplasmic signalling schemes and ultimately cell wall remodelling. The apoplastic polysaccharide matrix is, on the other hand, crucial for preventing proteins diffusing uncontrollably in the membrane. Therefore, the cell wall-plasma membrane link is essential for plant development and responses to external stimuli. This review focuses on the relationship between the cell wall and plasma membrane, and its importance for plant tissue organization. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Performance of a polymer sealant coating in an arctic marine environment

International Nuclear Information System (INIS)

Moskowitz, P.; Cowgill, M.; Griffith, A.; Chernaenko, L.; Diashev, A.; Nazarian, A.

2001-01-01

The feasibility of using a polymer-based coating, Polibrid 705, to seal concrete and steel surfaces from permanent radioactive contamination in an Arctic marine environment has been successfully demonstrated using a combination of field and laboratory testing. A mobile, self-sufficient spraying device was developed to specifications provided by the Russian Northern Navy and deployed at the RTP Atomflot site, Murmansk, Russia. Demonstration coatings were applied to concrete surfaces exposed to conditions ranging from indoor pedestrian usage to heavy vehicle passage and container handling in a loading dock. A large steel container was also coated with the polymer, filled with solid radwaste, sealed, and left out of doors, exposed to the full annual Arctic weather cycle. The 12 months of field testing gave rise to little degradation of the sealant coating, except for a few chips and gouge marks on the loading bay surface that were readily repaired. Contamination resulting from radwaste handling was easily removed and the surface was not degraded by contact with the decontamination agents. The field tests were accompanied by a series of laboratory qualification tests carried out at a research laboratory in St. Petersburg. The laboratory tests examined a variety of properties, including bond strength between the coating and the substrate, thermal cycling resistance, wear resistance, flammability, and ease of decontamination. The Polibrid 705 coating met all the Russian Navy qualification requirements with the exception of flammability. In this last instance, it was decided to restrict application of the coating to land-based facilities

Constitutive activation of a plasma membrane H+-ATPase prevents abscisic acid-mediated stomatal closure

Science.gov (United States)

Merlot, Sylvain; Leonhardt, Nathalie; Fenzi, Francesca; Valon, Christiane; Costa, Miguel; Piette, Laurie; Vavasseur, Alain; Genty, Bernard; Boivin, Karine; Müller, Axel; Giraudat, Jérôme; Leung, Jeffrey

2007-01-01

Light activates proton (H+)-ATPases in guard cells, to drive hyperpolarization of the plasma membrane to initiate stomatal opening, allowing diffusion of ambient CO2 to photosynthetic tissues. Light to darkness transition, high CO2 levels and the stress hormone abscisic acid (ABA) promote stomatal closing. The overall H+-ATPase activity is diminished by ABA treatments, but the significance of this phenomenon in relationship to stomatal closure is still debated. We report two dominant mutations in the OPEN STOMATA2 (OST2) locus of Arabidopsis that completely abolish stomatal response to ABA, but importantly, to a much lesser extent the responses to CO2 and darkness. The OST2 gene encodes the major plasma membrane H+-ATPase AHA1, and both mutations cause constitutive activity of this pump, leading to necrotic lesions. H+-ATPases have been traditionally assumed to be general endpoints of all signaling pathways affecting membrane polarization and transport. Our results provide evidence that AHA1 is a distinct component of an ABA-directed signaling pathway, and that dynamic downregulation of this pump during drought is an essential step in membrane depolarization to initiate stomatal closure. PMID:17557075

Caries progression in non-cavitated fissures after infiltrant application: a 3-year follow-up of a randomized controlled clinical trial

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Camillo ANAUATE-NETTO

Full Text Available Abstract Objectives To evaluate the efficacy of a conservative treatment to prevent the progression of caries using an infiltrant on non-cavitated pit and fissures. Material and Methods This controlled clinical trial selected 23 volunteers with clinically and radiographically non-cavitated occlusal caries among patients presenting a “rather low” to “very high” caries risk. Eighty-six teeth were randomly divided into two experimental groups: teeth receiving a commercial pit-and-fissure sealant (Alpha Seal-DFL and contralateral teeth receiving Icon infiltrant (DMG. Caries progression was monitored by clinical (laser fluorescence caries detection and radiographic examination at 12-month intervals over a period of 3 years of monitored caries progression. Probing the sealing materials to detect areas of retention was also used to evaluate marginal integrity. Results Statistical analysis showed no difference in caries progression using laser fluorescence caries detection when both materials were compared, regardless of the evaluation times (p>0.05. No significance was observed when the marginal sealant integrity of both materials was compared, regardless of the evaluation time (p0.05. SEM analysis exhibited a more homogeneous sealing for the infiltrant than obtained by the sealant. Conclusions The infiltrant was effective to prevent the caries progression in non-cavitated pit-and-fissures after 3 years of clinical evaluation, comparable with the conventional sealant. The infiltrant also presented better results in terms of caries progression at the 3-year evaluation time using the radiographic analysis.

Caries progression in non-cavitated fissures after infiltrant application: a 3-year follow-up of a randomized controlled clinical trial

Science.gov (United States)

ANAUATE-NETTO, Camillo; BORELLI, Laurindo; AMORE, Ricardo; DI HIPÓLITO, Vinicius; D’ALPINO, Paulo Henrique Perlatti

2017-01-01

Abstract Objectives To evaluate the efficacy of a conservative treatment to prevent the progression of caries using an infiltrant on non-cavitated pit and fissures. Material and Methods This controlled clinical trial selected 23 volunteers with clinically and radiographically non-cavitated occlusal caries among patients presenting a “rather low” to “very high” caries risk. Eighty-six teeth were randomly divided into two experimental groups: teeth receiving a commercial pit-and-fissure sealant (Alpha Seal-DFL) and contralateral teeth receiving Icon infiltrant (DMG). Caries progression was monitored by clinical (laser fluorescence caries detection) and radiographic examination at 12-month intervals over a period of 3 years of monitored caries progression. Probing the sealing materials to detect areas of retention was also used to evaluate marginal integrity. Results Statistical analysis showed no difference in caries progression using laser fluorescence caries detection when both materials were compared, regardless of the evaluation times (p>0.05). No significance was observed when the marginal sealant integrity of both materials was compared, regardless of the evaluation time (p0.05). SEM analysis exhibited a more homogeneous sealing for the infiltrant than obtained by the sealant. Conclusions The infiltrant was effective to prevent the caries progression in non-cavitated pit-and-fissures after 3 years of clinical evaluation, comparable with the conventional sealant. The infiltrant also presented better results in terms of caries progression at the 3-year evaluation time using the radiographic analysis. PMID:28877284

Efficacy of an internal teat seal associated with a dry cow intramammary antibiotic for prevention of intramammary infections in dairy cows during the dry and early lactation periods

Directory of Open Access Journals (Sweden)

Lívio R. Molina

Full Text Available ABSTRACT: The present study aimed to evaluate the use of an internal dry period teat seal containing bismuth subnitrate (Teatseal®, Zoetis®, Florham Park, Nova Jersey, USA associated with a long-acting cloxacilin preparation (Orbenin® Extra dry cow, Zoetis®, Florham Park, Nova Jersey, USA, in preventing new infections during the dry-off and early postpartum period. A total of 150 Holstein cows (average production of 9,000 kg of milk per lactation, with four functional udder quarters without clinical mastitis was included in the study. All animals were dried-off 60 days before the expected calving date. Two teats positioned diagonal-contralaterally received only dry cow antibiotic, control group C (n=300 and the other two teats, treatment group T (n=300 received dry cow antibiotic and infusion with an internal teat seal. Data from SCC variable were transformed by log base-10 transformation. Duncan’s test was used accepting 5% as the level of statistical significance. The occurrence of intramammary infection (IMI and chronicity rate, and frequency of microorganisms isolated at drying and immediately postpartum in teats of group C and group T were evaluated using a non-parametric Chi-square Test, accepting 10% as the statistical significance level. There was a decrease in the occurrence of new infections in the early postpartum in cows which the sealant was used (C=19.6%, T=11.4%. In the postpartum period, Gram-negative bacteria were isolated from 16 teats in C and seven in T. The greatest reduction was observed for Escherichia coli (8 vs 1 in group T. There was no effect using the internal sealant on the frequency of isolation of environmental Streptococus. The use of sealant reduced the prevalence of subclinical mastitis cows between drying-off and the early postpartum period (C=51% versus T=42% and resulted in a lower somatic cell count (SCC in the treatment group when compared with the control group (T=1,073x103, C=1,793x103. The use of

Avaliação clínica de um cimento de ionômero de vidro utilizado como selante oclusal: a clinical evaluation Use of a glass ionomer cement as an occlusal sealant

Directory of Open Access Journals (Sweden)

Pedro Cheque BERNARDO

2000-03-01

Full Text Available Sabendo-se do papel do flúor na Odontologia Preventiva, cada vez mais procuram-se materiais restauradores com propriedades de liberação deste íon. Dentre os selantes oclusais, grande expectativa existe em relação aos cimentos de ionômero de vidro, particularmente os fotopolimerizáveis, por possuírem melhores propriedades. O objetivo deste trabalho foi testar um destes cimentos, Vitremer (3M, aplicado em: combinação ou não com um adesivo. A avaliação foi realizada em 159 dentes, 6 e 12 meses após a aplicação do selante, observando-se sua retenção e a presença ou ausência de lesão de cárie. Concluiu-se que a técnica modificada, com adesivo, propiciou significativamente melhor retenção após 6 e 12 meses que a técnica convencional, não havendo diferença entre molares e pré-molares. Apenas um dente do grupo sem adesivo desenvolveu lesão de cárie após a perda do material.Since fluoride’s properties are widely known in the field of Preventive Dentistry, fluoride-releasing materials have been extensively investigated. Among the occlusal sealants, there is great expectation regarding the results that can be achieved with light-curing glass-ionomer cements due to their excellent properties. The aim of this study was to assess the use of one of these cements, Vitremer (3M as an occlusal sealant. The material was applied using two different techniques; either associated or not with an adhesive system. After 6 and 12 months of observation, an evaluation was performed in 159 teeth to verify its retention as well as the presence of caries lesions. The technique that included the adhesive system showed better retention than the conventional one. Total retention was 84.9% for the experimental technique and 37.2% for the conventional technique after 12 months. There was no difference between bicuspids and molars regarding retention. Caries lesion was observed in a single tooth, for which a total loss of material was observed

Use of caries-preventive agents in children: findings from the dental practice-based research network.

Science.gov (United States)

Riley, J L; Richman, Joshua S; Rindal, D Brad; Fellows, Jeffrey L; Qvist, Vibeke; Gilbert, Gregg H; Gordan, Valeria V

2010-01-01

Scientific evidence supports the application of caries-preventive agents in children and adolescents, and this knowledge must be applied to the practice of dentistry. There are few multi-region data that allow for comparisons of practice patterns between types of dental practices and geographical regions. The objective of the present study was to characterise the use of specific caries-preventive agents for paediatric patients in a large multi-region sample of practising clinicians. The present study surveyed clinicians from the Dental Practice-based Research Network who perform restorative dentistry in their practices. The survey consisted of a questionnaire that presented a range of questions about caries risk assessment and the use of preventive techniques in children aged 6 to 18 years. Dental sealants (69%) or in-office fluoride (82%) were the most commonly used caries-preventive agents of the caries preventive regimens. The recommendation of at-home caries-preventive agents ranged from 36% to 7%,with the most commonly used agent being non-prescription fluoride rinse. Clinicians who practised in a large group practice model and clinicians who come from the Scandinavian region use caries risk assessment more frequently compared to clinicians who come from regions that had, predominantly, clinicians in private practice. Whether or not clinicians used caries risk assessment with their paediatric patients was poorly correlated with the likelihood of actually using caries-preventive treatments on patients. Although clinicians reported the use of some form of in-office caries-preventive agent, there was considerable variability across practices. These differences could represent a lack of consensus across practising clinicians about the benefits of caries-preventive agents, or a function of differing financial incentives, or patient pools with differing levels of overall caries risk.

Major Intrinsic Proteins in Biomimetic Membranes

DEFF Research Database (Denmark)

Helix Nielsen, Claus

2010-01-01

or as sensor devices based on e.g., the selective permeation of metalloids. In principle a MIP based membrane sensor/separation device requires the supporting biomimetic matrix to be virtually impermeable to anything but water or the solute in question. In practice, however, a biomimetic support matrix....../separation technology, a unique class of membrane transport proteins is especially interesting the major intrinsic proteins (MIPs). Generally, MIPs conduct water molecules and selected solutes in and out of the cell while preventing the passage of other solutes, a property critical for the conservation of the cells...... internal pH and salt concentration. Also known as water channels or aquaporins they are highly efficient membrane pore proteins some of which are capable of transporting water at very high rates up to 109 molecules per second. Some MIPs transport other small, uncharged solutes, such as glycerol and other...

MAL Is a Regulator of the Recruitment of Myelin Protein PLP to Membrane Microdomains

NARCIS (Netherlands)

Bijlard, Marjolein; de Jonge, Jenny C.; Klunder, Bert; Nomden, Anita; Hoekstra, Dick; Baron, Wia

2016-01-01

In oligodendrocytes (OLGs), an indirect, transcytotic pathway is mediating transport of de novo synthesized PLP, a major myelin specific protein, from the apical-like plasma membrane to the specialized basolateral-like myelin membrane to prevent its premature compaction. MAL is a well-known

BID is cleaved by caspase-8 within a native complex on the mitochondrial membrane

NARCIS (Netherlands)

Schug, Z. T.; Gonzalvez, F.; Houtkooper, R. H.; Vaz, F. M.; Gottlieb, E.

2011-01-01

Caspase-8 stably inserts into the mitochondrial outer membrane during extrinsic apoptosis. Inhibition of caspase-8 enrichment on the mitochondria impairs caspase-8 activation and prevents apoptosis. However, the function of active caspase-8 on the mitochondrial membrane remains unknown. In this

Socioeconomic inequality in the provision of specific preventive dental interventions among children in the UK: Children's Dental Health Survey 2003.

Science.gov (United States)

Shaban, R; Kassim, S; Sabbah, W

2017-06-09

Aim To assess socioeconomic inequality regarding specific preventive interventions (fissure sealants or any treatment to prevent caries) and dental visits among UK children.Method Data were from the Children's Dental Health Survey 2003, which included participants from England, Wales, Scotland, and Northern Ireland. The number of children in the analysis was 2,286. Variables were sex, age, area of residency (for example, England), mother's education, family social class, and deprivation level. Descriptive and regression analyses were performed.Results There were no significant socioeconomic differences in the use of preventive services. Deprivation and family social class (for example, intermediate and manual) were significantly associated with less regular dental visits (odd ratio 0.41, 95% CI [0.28, 0.63]; odd ratio 0.53, 95% CI [0.31, 0.89]; odd ratio 0.37, 95% CI [0.24, 0.58], respectively). Regular dental visits were associated with reporting preventive care for caries (odds ratio 2.25, 95% CI [1.45, 3.49]) and with the number of sealed tooth surfaces (rate ratio 1.73, 95% CI [1.16, 2.60]).Conclusion Despite apparent socioeconomic inequalities in regular dental visits, there was no significant inequality in using specific preventive interventions by children in the UK. This finding should be interpreted with caution considering the relatively small subsample included in this analysis.

Understanding carbon nanotube channel formation in the lipid membrane

Science.gov (United States)

Choi, Moon-ki; Kim, Hyunki; Lee, Byung Ho; Kim, Teayeop; Rho, Junsuk; Kim, Moon Ki; Kim, Kyunghoon

2018-03-01

Carbon nanotubes (CNTs) have been considered a prominent nano-channel in cell membranes because of their prominent ion-conductance and ion-selectivity, offering agents for a biomimetic channel platform. Using a coarse-grained molecular dynamics simulation, we clarify a construction mechanism of vertical CNT nano-channels in a lipid membrane for a long period, which has been difficult to observe in previous CNT-lipid interaction simulations. The result shows that both the lipid coating density and length of CNT affect the suitable fabrication condition for a vertical and stable CNT channel. Also, simulation elucidated that a lipid coating on the surface of the CNT prevents the CNT from burrowing into the lipid membrane and the vertical channel is stabilized by the repulsion force between the lipids in the coating and membrane. Our study provides an essential understanding of how CNTs can form stable and vertical channels in the membrane, which is important for designing new types of artificial channels as biosensors for bio-fluidic studies.

Aspirin Increases the Solubility of Cholesterol in Lipid Membranes

Science.gov (United States)

Alsop, Richard; Barrett, Matthew; Zheng, Sonbo; Dies, Hannah; Rheinstadter, Maikel

2014-03-01

Aspirin (ASA) is often prescribed for patients with high levels of cholesterol for the secondary prevention of myocardial events, a regimen known as the Low-Dose Aspirin Therapy. We have recently shown that Aspirin partitions in lipid bilayers. However, a direct interplay between ASA and cholesterol has not been investigated. Cholesterol is known to insert itself into the membrane in a dispersed state at moderate concentrations (under ~37.5%) and decrease fluidity of membranes. We prepared model lipid membranes containing varying amounts of both ASA and cholesterol molecules. The structure of the bilayers as a function of ASA and cholesterol concentration was determined using high-resolution X-ray diffraction. At cholesterol levels of more than 40mol%, immiscible cholesterol plaques formed. Adding ASA to the membranes was found to dissolve the cholesterol plaques, leading to a fluid lipid bilayer structure. We present first direct evidence for an interaction between ASA and cholesterol on the level of the cell membrane.

Polymer Inclusion Membranes with Strip Dispersion

Directory of Open Access Journals (Sweden)

Yueh-Hsien Li

2017-06-01

Full Text Available The present work investigated the permeation of indium ions through a polymer inclusion membrane (PIM, prepared with cellulose triacetate (CTA as the base polymer, tris(2-butoxyethyl phosphate (TBEP as the plasticizer and di-(2-ethylhexylphosphoric acid (D2EHPA as the extractant. With 5 M HCl aqueous solution as the strip solution, we observed an initial indium permeability of 2.4 × 10−4 m/min. However, the permeability decreases with time, dropping to about 3.4 × 10−5 m/min after 200 min of operation. Evidence was obtained showing that hydrolysis of CTA occurred, causing a dramatic decrease in the feed pH (protons transported from strip to feed solutions and a loss of extractant and plasticizer from the membrane, and then leading to the loss of indium permeability. To alleviate the problem of hydrolysis, we proposed an operation scheme called polymer inclusion membranes with strip dispersion: dispersing the strip solution in extractant-containing oil and then bringing the dispersion to contact with the polymer membrane. Since the strong acid was dispersed in oil, the membrane did not directly contact the strong acid at all times, and membrane hydrolysis was thus alleviated and the loss of indium permeability was effectively prevented. With the proposed scheme, a stable indium permeability of 2.5 × 10−4 m/min was obtained during the whole time period of the permeation experiment.

The electrolysis time on electrosynthesis of hydroxyapatite with bipolar membrane

Science.gov (United States)

Nur, Adrian; Jumari, Arif; Budiman, Anatta Wahyu; Puspitaningtyas, Stella Febianti; Cahyaningrum, Suci; Nazriati, Nazriati; Fajaroh, Fauziatul

2018-02-01

The electrochemical method with bipolar membrane has been successfully used for the synthesis of hydroxyapatite. In this work, we have developed 2 chambers electrolysis system separated by a bipolar membrane. The membrane was used to separate cations (H+ ions produced by the oxidation of water at the anode) and anions (OH- ions produced by the reduction of water at the cathode). With this system, we have designed that OH- ions still stay in the anions chamber because OH- ions was very substantial in the hydroxyapatite particles formation. The aim of this paper was to compare the electrolysis time on electrosynthesis of hydroxyapatite with and without the bipolar membrane. The electrosynthesis was performed at 500 mA/cm2 for 0.5 to 2 hours at room temperature and under ultrasonic cleaner to void agglomeration with and without the bipolar membrane. The electrosynthesis of hydroxyapatite with the bipolar membrane more effective than without the bipolar membrane. The hydroxyapatite has been appeared at 0.5 h of the electrolysis time with the bipolar membrane (at the cathode chamber) while it hasn't been seen without the bipolar membrane. The bipolar membrane prevents OH- ions migrate to the cation chamber. The formation of HA becomes more effective because OH- ions just formed HA particle.

THE OUTER MEMBRANE OF PATHOGENIC REPRESENTATIVES OF THE LEPTOSPIRA GENIUS

Directory of Open Access Journals (Sweden)

A. N. Vaganova

2011-01-01

Full Text Available Abstract. Pathogenic leptospires can infect wide spectrum of hosts and they can survive in the environment long time. The outer membrane is the cellular component participated in interaction of microorganisms and environment. In present time several proteins located in the outer membrane of leptospires which are responsible for colonization of host organism, protection from influence of immune system of host, transport of substances in to the cell and other processes have been described. The outer membrane contains proteins and lipopolysaccharide molecules which have citotoxic effect. It was shown that regulation of protein composition of membranes depends on several factors of environment such as temperature, osmolarity, presence of certain substances in environment. Lipopolysaccharide and protein molecules of outer membranes have antigenic properties. These molecules can be used in practice as the components of vaccine against leptospiroses and diagnostic tools. Current review summarize information concerning structural organization of the outer membrane of leptospires, diversities of incoming parts of molecules and regulation of their synthesis. Moreover, perspectives of practical using of the outer membrane components in diagnostics and prevention of leptospiroses are presented.

Functional implications of plasma membrane condensation for T cell activation.

Directory of Open Access Journals (Sweden)

Carles Rentero

2008-05-01

Full Text Available The T lymphocyte plasma membrane condenses at the site of activation but the functional significance of this receptor-mediated membrane reorganization is not yet known. Here we demonstrate that membrane condensation at the T cell activation sites can be inhibited by incorporation of the oxysterol 7-ketocholesterol (7KC, which is known to prevent the formation of raft-like liquid-ordered domains in model membranes. We enriched T cells with 7KC, or cholesterol as control, to assess the importance of membrane condensation for T cell activation. Upon 7KC treatment, T cell antigen receptor (TCR triggered calcium fluxes and early tyrosine phosphorylation events appear unaltered. However, signaling complexes form less efficiently on the cell surface, fewer phosphorylated signaling proteins are retained in the plasma membrane and actin restructuring at activation sites is impaired in 7KC-enriched cells resulting in compromised downstream activation responses. Our data emphasizes lipids as an important medium for the organization at T cell activation sites and strongly indicates that membrane condensation is an important element of the T cell activation process.

Development of robust fluorinated TiO2/PVDF composite hollow fiber membrane for CO2 capture in gas-liquid membrane contactor

Science.gov (United States)

Lin, Yuqing; Xu, Yilin; Loh, Chun Heng; Wang, Rong

2018-04-01

Gas-liquid membrane contactor (GLMC) is a promising method to attain high efficiency for CO2 capture from flue gas, biogas and natural gas. However, membranes used in GLMC are prone to pore wetting due to insufficient hydrophobicity and low chemical resistance, resulting in significant increase in mass transfer resistance. To mitigate this issue, inorganic-organic fluorinated titania/polyvinylidene fluoride (fTiO2/PVDF) composite hollow fiber (HF) membranes was prepared via facile in-situ vapor induced hydrolyzation method, followed by hydrophobic modification. The proposed composite membranes were expected to couple the superb chemical stability of inorganic and high permeability/low cost of organic materials. The continuous fTiO2 layer deposited on top of PVDF substrate was found to possess a tighter microstructure and better hydrophobicity, which effectively prevented the membrane from wetting and lead to a high CO2 absorption flux (12.7 × 10-3 mol m-2 s-1). In a stability test with 21-day operation of GLMC using 1M monoethanolamine (MEA) as the absorbent, the fTiO2/PVDF membrane remained to be intact with a CO2 absorption flux decline of ∼16%, while the pristine PVDF membrane suffered from a flux decline of ∼80% due to membrane damage. Overall, this work provides an insight into the preparation of high-quality inorganic/organic composite HF membranes for CO2 capture in GLMC application.

Effective and rapid sealing of coronary, aortic and atrial suture lines †.

Science.gov (United States)

Skorpil, Jiri; Paraforos, Alexandros; Mandak, Jiri; Cohn, William E; Hajek, Tomas; Friedrich, Ivan

2015-06-01

Cardiac surgical procedures carry a high risk of perioperative bleeding. Surgical sealants are often used to prevent suture line bleeding. PreveLeak™ is a surgical sealant composed of bovine serum albumin, a polyaldehyde cross-linker, and other components that forms a soft, flexible, water-tight, mechanical seal that is biocompatible and bioresorbable. A prospective, multicentre study evaluated PreveLeak use in 44 subjects undergoing 63 cardiac procedures, primarily coronary artery bypass grafting (n = 23/63, 36.5%) and aortic valve replacement (n = 19/63, 30.2%). PreveLeak was applied to 127 suture lines and the time to sealing evaluated upon clamp release. The primary safety endpoint was the incidence of significant bleeding, infections, neurological deficits and immune/inflammatory allergic responses within 6 weeks post-treatment; subjects were followed for 3 months. Immediate sealing was achieved at all sites in 42 of 44 subjects (95.5%) and 125 of 127 treatment sites (98.4%). There were nine primary safety events: eight infections and one transient neurological deficit. Most adverse events were mild (n = 46/71, 64.8%) or moderate (n = 18/71, 25.4%) in severity. One adverse event (transient vasospasm) was considered possibly sealant-related. One death occurred due to a cardiac arrest. PreveLeak prevented bleeding at 98.4% of treated sites and was well tolerated; adverse events were consistent with those commonly observed in subjects undergoing surgical procedures. These results compared favourably with published studies of other sealants. The observed prevention of bleeding is clinically important in cardiac surgical patients. A randomized, comparative study is justified to further evaluate PreveLeak and confirm the findings from this study. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Basolateral cholesterol depletion alters Aquaporin-2 post-translational modifications and disrupts apical plasma membrane targeting.

Science.gov (United States)

Moeller, Hanne B; Fuglsang, Cecilia Hvitfeldt; Pedersen, Cecilie Nøhr; Fenton, Robert A

2018-01-01

Apical plasma membrane accumulation of the water channel Aquaporin-2 (AQP2) in kidney collecting duct principal cells is critical for body water homeostasis. Posttranslational modification (PTM) of AQP2 is important for regulating AQP2 trafficking. The aim of this study was to determine the role of cholesterol in regulation of AQP2 PTM and in apical plasma membrane targeting of AQP2. Cholesterol depletion from the basolateral plasma membrane of a collecting duct cell line (mpkCCD14) using methyl-beta-cyclodextrin (MBCD) increased AQP2 ubiquitylation. Forskolin, cAMP or dDAVP-mediated AQP2 phosphorylation at Ser269 (pS269-AQP2) was prevented by cholesterol depletion from the basolateral membrane. None of these effects on pS269-AQP2 were observed when cholesterol was depleted from the apical side of cells, or when MBCD was applied subsequent to dDAVP stimulation. Basolateral, but not apical, MBCD application prevented cAMP-induced apical plasma membrane accumulation of AQP2. These studies indicate that manipulation of the cholesterol content of the basolateral plasma membrane interferes with AQP2 PTM and subsequently regulated apical plasma membrane targeting of AQP2. Copyright © 2017 Elsevier Inc. All rights reserved.

Solubilization of rat kidney plasma membrane proteins associated with 3H-aldosterone

International Nuclear Information System (INIS)

Ozegovic, B.; Dobrovic-Jenik, D.; Milkovic, S.

1988-01-01

The treatment of rat kidney plasma membranes with sodium dodecyl sulphate (SDS) did not essentially affect the ability of the membranes for 3 H-aldosterone binding as compared with the intact plasma membranes (Ozegovic et al., 1977). A gel filtration of 3 H-aldosterone - kidney plasma membranes complex on Sepharose 6B yielded 2 protein and 2 3 H-aldosterone peaks. The proteins which were eluted in the first peak were associated with the first 3 H-aldosterone peak while the second 3 H-aldosterone peak was eluted with Ve corresponding to Ve of free 3 H-aldosterone. Spironolactone, a competitive antagonist of aldosterone, prevented the binding of 3 H-aldosterone to the membrane proteins. The results demonstrated a high affinity of the kidney plasma membranes solubilized with SDS and a specificity of aldosterone binding to the plasma membrane proteins of higher molecular mass. (author)

Fouling-Resistant Membranes for Treating Concentrated Brines for Water Reuse in Advanced Energy Systems

Energy Technology Data Exchange (ETDEWEB)

Hendren, Zachary [RTI International, Research Triangle Park, NC (United States); Choi, Young Chul [RTI International, Research Triangle Park, NC (United States)

2014-10-14

The high total dissolved solids (TDS) levels in the wastewater quality generated from unconventional oil and gas development make the current state-of-the art approach to water treatment/disposal untenable. Our proposed membrane technology approach addresses the two major challenges associated with this water: 1) the membrane distillation process removes the high TDS content, which is often 8 times higher than that of seawater, and 2) our novel membrane coating prevents the formation of scale that would otherwise pose a significant operational hurdle. This is accomplished through next-generation electrically conductive membranes that mitigate fouling beyond what is currently possible, and allow for the flexibility to treat to the water to levels desirable for multiple reuse options, thus reducing fresh water withdrawal, all the way to direct disposal into the environment. The overall project objective was to demonstrate the efficacy of membrane distillation (MD) as a cost-savings technology to treat concentrated brines (such as, but not limited to, produced waters generated from fossil fuel extraction) that have high levels of TDS for beneficial water reuse in power production and other industrial operations as well as agricultural and municipal water uses. In addition, a novel fouling-resistant nanocomposite membrane was developed to reduce the need for chemicals to address membrane scaling due to the precipitation of divalent ions in high-TDS waters and improve overall MD performance via an electrically conductive membrane distillation process (ECMD). This anti-fouling membrane technology platform is based on incorporating carbon nanotubes (CNTs) into the surface layer of existing, commercially available MD membranes. The CNTs impart electrical conductivity to the membrane surface to prevent membrane scaling and fouling when an electrical potential is applied.

Virus Disinfection in Water by Biogenic Silver Immobilized in Polyvinylidene Fluoride Membranes

Energy Technology Data Exchange (ETDEWEB)

B De Gusseme; T Hennebel; E Christiaens; H Saveyn; K Verbeken; J Fitts; N Boon; W Vertraete

2011-12-31

The development of innovative water disinfection strategies is of utmost importance to prevent outbreaks of waterborne diseases related to poor treatment of (drinking) water. Recently, the association of silver nanoparticles with the bacterial cell surface of Lactobacillus fermentum (referred to as biogenic silver or bio-Ag{sup 0}) has been reported to exhibit antiviral properties. The microscale bacterial carrier matrix serves as a scaffold for Ag{sup 0} particles, preventing aggregation during encapsulation. In this study, bio-Ag{sup 0} was immobilized in different microporous PVDF membranes using two different pre-treatments of bio-Ag{sup 0} and the immersion-precipitation method. Inactivation of UZ1 bacteriophages using these membranes was successfully demonstrated and was most probably related to the slow release of Ag{sup +} from the membranes. At least a 3.4 log decrease of viruses was achieved by application of a membrane containing 2500 mg bio-Ag{sup 0}{sub powder} m{sup -2} in a submerged plate membrane reactor operated at a flux of 3.1 L m{sup -2} h{sup -1}. Upon startup, the silver concentration in the effluent initially increased to 271 {mu}g L{sub -1} but after filtration of 31 L m{sup -2}, the concentration approached the drinking water limit (= 100 {mu}g L{sup -1}). A virus decline of more than 3 log was achieved at a membrane flux of 75 L m{sup -2} h{sup -1}, showing the potential of this membrane technology for water disinfection on small scale.

The effect of sodium hyaluronate-carboxymethyl cellulose membrane in the prevention of parenchymal air leaks: an experimental and manometric study in rats.

Science.gov (United States)

Büyükkale, Songül; Çıtak, Necati; İşgörücü, Özgür; Sayar, Adnan

2017-12-01

We aimed to examine effectiveness of sodium hyaluronate-carboxymethly cellulose (NaH/CMC) for sealing pulmonary air leaks during postoperative period. The study was conducted in 16 male Sprague-Dawley rats. A linear insicion (length= 0.2 cm, depth= 0.1 cm) to the lung parenchyma on the inflated by a cutter was made. The animals were randomly divided; the control group (n= 8) and NaH/CMC-treated group (the study group, n= 8). Control group was left for physiologic healing while a NaH/CMC membrane was applied over the the incisional area in the study group. Then the pressure point where the air leakage observed was noted. No polymorphonucleer leucocytes (PMNL) infiltration was detected in control group, whereas PMNL infiltration was 0.38 ± 0.5 cell per 100 high field in study group (p= 0.234). The degree of macrophage, lymphocyte infiltration and the mean fibroblast count were found to be higher in study group compared with control group (p= 0.007, p= 0.02, p= 0.05, respectively). The mean pressure value for air leak to occur in the control group was 43.50 ± 9.55 mmHg whereas it was 73.75 ± 16.68 mmHg in the study group (p< 0.001). The data revealed that bioabsorbable NaH/CMC membrane accelerates healing with preserving the expansile character of lung parenchyma even in high ventilation pressures. However, further studies are required to assess the prevent impact of the pulmonary air-leak for NaH/CMC membrane.

Antibacterial and anti-adhesion effects of the silver nanoparticles-loaded poly(L-lactide) fibrous membrane

International Nuclear Information System (INIS)

Liu, Shen; Zhao, Jingwen; Ruan, Hongjiang; Wang, Wei; Wu, Tianyi; Cui, Wenguo; Fan, Cunyi

2013-01-01

The complications of tendon injury are frequently compromised by peritendinous adhesions and tendon sheath infection. Physical barriers for anti-adhesion may increase the incidence of postoperative infection. This study was designed to evaluate the potential of silver nanoparticles (AgNPs)-loaded poly(L-lactide) (PLLA) electrospun fibrous membranes to prevent adhesion formation and infection. Results of an in vitro drug release study showed that a burst release was followed by sustained release from electrospun fibrous membranes with a high initial silver content. Fewer fibroblasts adhered to and proliferated on the AgNP-loaded PLLA electrospun fibrous membranes compared with pure PLLA electrospun fibrous membrane. In the antibacterial test, the AgNP-loaded PLLA electrospun fibrous membranes can prevent the adhesion of Gram-positive Staphylococcus aureus and Staphylococcus epidermidis and Gram-negative Pseudomonas aeruginosa. Taken together, these results demonstrate that AgNP-loaded PLLA electrospun fibrous membranes have the convenient practical medical potential of reduction of infection and adhesion formation after tendon injury. - Highlights: ► Silver nanoparticles are directly electrospun into PLLA fibrous membrane. ► Long-lasting release of Ag + ions is achieved. ► Cytotoxicity of silver ions benefits the anti-proliferation of physical barriers. ► Broad anti-microbial effect of drug-loaded fibrous membrane is revealed. ► Antibacterial and anti-adhesion effects of the physical barriers are combined

Biglycan and decorin differentially regulate signaling in the fetal membranes

Science.gov (United States)

Wu, Zhiping; Horgan, Casie E.; Carr, Olivia; Owens, Rick T.; Iozzo, Renato V.; Lechner, Beatrice E.

2014-01-01

Preterm birth is the leading cause of newborn mortality in the United States and about one third of cases are caused by preterm premature rupture of fetal membranes, a complication that is frequently observed in patients with Ehlers-Danlos Syndrome. Notably, a subtype of Ehlers-Danlos Syndrome is caused by expression of abnormal biglycan and decorin proteoglycans. As compound deficiency of these two small leucine-rich proteoglycans is a model of preterm birth, we investigated the fetal membranes of Bgn−/−;Dcn−/− double-null and single-null mice. Our results showed that biglycan signaling supported fetal membrane remodeling during early gestation in the absence of concomitant changes in TGFβ levels. In late gestation, biglycan signaling acted in a TGFβ–dependent manner to aid in membrane stabilization. In contrast, decorin signaling supported fetal membrane remodeling at early stages of gestation in a TGFβ–dependent manner, and fetal membrane stabilization at later stages of gestation without changes in TGFβ levels. Furthermore, exogenous soluble decorin was capable of rescuing the TGFβ signaling pathway in fetal membrane mesenchymal cells. Collectively, these findings provide novel targets for manipulation of fetal membrane extracellular matrix stability and could represent novel targets for research on preventive strategies for preterm premature rupture of fetal membranes. PMID:24373743

FLUX ENHANCEMENT IN CROSSFLOW MEMBRANE FILTRATION: FOULING AND IT'S MINIMIZATION BY FLOW REVERSAL

International Nuclear Information System (INIS)

Shamsuddin Ilias

2005-01-01

Fouling problems are perhaps the single most important reason for relatively slow acceptance of ultrafiltration in many areas of chemical and biological processing. To overcome the losses in permeate flux associated with concentration polarization and fouling in cross flow membrane filtration, we investigated the concept of flow reversal as a method to enhance membrane flux in ultrafiltration. Conceptually, flow reversal prevents the formation of stable hydrodynamic and concentration boundary layers at or near the membrane surface. Further more, periodic reversal of the flow direction of the feed stream at the membrane surface results in prevention and mitigation of membrane fouling. Consequently, these advantages are expected to enhance membrane flux significantly. A crossflow membrane filtration unit was designed and built to test the concept of periodic flow reversal for flux enhancement. The essential elements of the system include a crossflow hollow fiber membrane module integrated with a two-way valve to direct the feed flow directions. The two-way valve is controlled by a controller-timer for periodic reversal of flow of feed stream. Another important feature of the system is that with changing feed flow direction, the permeate flow direction is also changed to maintain countercurrent feed and permeate flows for enhanced mass transfer driving force (concentration difference). In this report, we report our application of Flow Reversal technique in clarification of apple juice containing pectin. The presence of pectin in apple juice makes the clarification process difficult and is believed to cause membrane fouling. Of all compounds found in apple juice, pectin is most often identified as the major hindrance to filtration performance. Based on our ultrafiltration experiments with apple juice, we conclude that under flow reversal conditions, the permeate flux is significantly enhanced when compared with the conventional unidirectional flow. Thus, flow reversal

Development of Membrane Contactors Using Phase Change Solvents for CO2 Capture: Material Compatibility Study

OpenAIRE

Ansaloni, Luca; Asad, Arif; Çiftja, Arlinda; Knuutila, Hanna K; Deng, Liyuan

2016-01-01

Phase change solvents represent a new class of CO2 absorbents with a promising potential to reduce the energy penalty associated with CO2 capture. However, their high volatility is a major concern for their use at the industrial scale. It is believed that membrane absorption offers a solution to overcome this issue, particularly if the membrane can prevent amine evaporation. In the present work a compatibility study is carried out in order to identify suitable membranes in a membrane contacto...

Enhanced starch hydrolysis using α-amylase immobilized on cellulose ultrafiltration affinity membrane.

Science.gov (United States)

Konovalova, Viktoriia; Guzikevich, Kateryna; Burban, Anatoliy; Kujawski, Wojciech; Jarzynka, Karolina; Kujawa, Joanna

2016-11-05

In order to prepare ultrafiltration membranes possessing biocatalytic properties, α-amylase has been immobilized on cellulose membranes. Enzyme immobilization was based on a covalent bonding between chitosan and a surface of cellulose membrane, followed by an attachment of Cibacron Blue F3G-A dye as affinity ligand. Various factors affecting the immobilization process, such as enzyme concentration, pH of modifying solution, zeta-potential of membrane surface, and stability of immobilized enzyme were studied. The applicability of immobilized α-amylase has been investigated in ultrafiltration processes. The immobilization of α-amylase on membrane surface allows to increase the value of mass transfer coefficient and to decrease the concentration polarization effect during ultrafiltration of starch solutions. The enzyme layer on the membrane surface prevents a rapid increase of starch concentration due to the amylase hydrolysis of starch in the boundary layer. The presented affinity immobilization technique allows also for the regeneration of membranes from inactivated enzyme. Copyright © 2016 Elsevier Ltd. All rights reserved.

Virus disinfection in water by biogenic silver immobilized in polyvinylidene fluoride membranes

Energy Technology Data Exchange (ETDEWEB)

Gusseme, B.D.; Fitts, J.; Hennebel, T.; Christiaens, E.; Saveyn, H.; Verbeken, K.; Boon, N.; Verstraete, W.

2011-03-01

The development of innovative water disinfection strategies is of utmost importance to prevent outbreaks of waterborne diseases related to poor treatment of (drinking) water. Recently, the association of silver nanoparticles with the bacterial cell surface of Lactobacillus fermentum (referred to as biogenic silver or bio-Ag{sup 0}) has been reported to exhibit antiviral properties. The microscale bacterial carrier matrix serves as a scaffold for Ag{sup 0} particles, preventing aggregation during encapsulation. In this study, bio-Ag{sup 0} was immobilized in different microporous PVDF membranes using two different pre-treatments of bio-Ag{sup 0} and the immersion-precipitation method. Inactivation of UZ1 bacteriophages using these membranes was successfully demonstrated and was most probably related to the slow release of Ag{sup +} from the membranes. At least a 3.4 log decrease of viruses was achieved by application of a membrane containing 2500 mg bio-Ag{sub powder}{sup 0} m{sup -2} in a submerged plate membrane reactor operated at a flux of 3.1 L m{sup -2} h{sup -1}. Upon startup, the silver concentration in the effluent initially increased to 271 {micro}g L{sup -1} but after filtration of 31 L m{sup -2}, the concentration approached the drinking water limit (= 100 {micro}g L{sup -1}). A virus decline of more than 3 log was achieved at a membrane flux of 75 L m{sup -2} h{sup -1}, showing the potential of this membrane technology for water disinfection on small scale. In biogenic silver, silver nanoparticles are attached to a bacterial carrier matrix. Bio-Ag{sup 0} was successfully immobilized in PVDF membranes using immersion-precipitation. The antiviral activity of this material was demonstrated in a plate membrane reactor. The antimicrobial mechanism was most probably related to the slow release of Ag{sup +} ions. The membranes can be applied for treatment of limited volumes of contaminated water.

[Evaluation of the effect of one-step self etching adhesives applied in pit and fissure sealing].

Science.gov (United States)

Su, Hong-Ru; Xu, Pei-Cheng; Qian, Wen-Hao

2016-06-01

To observe the effect of three one-step self etching adhesive systems used in fit and fissure sealant and explore the feasibility of application in caries prevention in school. Seven hundred and twenty completely erupted mandibular first molars in 360 children aged 7 to 9 years old were chosen. The split-mouth design was used to select one side as the experimental group, divided into A1(Easy One Adper), B1(Adper Easy One), and C1(iBond SE).The contra lateral teeth served as A2,B2 and C2 groups (phosphoric acid). The retention and caries status were regularly reviewed .The clinical effect of the two groups was compared using SPSS19.0 software package for Chi - square test. At 3 and 6 months, pit and fissure sealant retention rate in A1 and A2, B1 and B2,C1 and C2 group had no significant difference. At 12 months, sealant retention in A1 and B1 group was significantly lower than A2 and B2 group (P0.05). At 24 months, sealant retention rate in A1, B1 and C1 group was significantly lower than A2, B2 and C2 group (P0.05). The clinical anticariogenic effect of three kinds of one-step etching adhesives and phosphoric acid etching sealant was similar .One-step self etching adhesive system was recommended for pit and fissure sealant to improve the students' oral health. The long-term retention rate of one-step self etching adhesive system was lower than the phosphoric acid method to long term observation is needed.

Fouling mitigation in membrane distillation processes during ammonia stripping from pig manure

DEFF Research Database (Denmark)

Zarebska, Agata; Amor, Angel Cid; Ciurkot, Klaudia

2015-01-01

Over time fouling leads to membrane wetting. This is the biggest obstacle to widespread use of membrane distillation (MD) for ammonia removal from animal slurry. Feed pretreatment and cleaning strategies of membrane surfaces are the most common methods to prevent or diminish fouling phenomena....... This study investigates preliminary fouling of polypropylene (PP) and polytetrafluoroethylene (PTFE) membranes. A model manure solution was used as feed. In addition cleaning efficiencies with deionized water, NaOH/citric acid, and Novadan agents were studied. Further microfiltration and ultrafiltration were...... examined as manure pretreatment to diminish fouling. To this end polyvinylidene fluoride membranes (PVDF 0.2 µm and 150 kDa respectively) were used. Organic fouling was shown to be dominant. For the model manure solution the fouling comprised lipids, carbohydrates and proteins. For pig slurry the fouling...

Membranes, methods of making membranes, and methods of separating gases using membranes

Science.gov (United States)

Ho, W. S. Winston

2012-10-02

Membranes, methods of making membranes, and methods of separating gases using membranes are provided. The membranes can include at least one hydrophilic polymer, at least one cross-linking agent, at least one base, and at least one amino compound. The methods of separating gases using membranes can include contacting a gas stream containing at least one of CO.sub.2, H.sub.2S, and HCl with one side of a nonporous and at least one of CO.sub.2, H.sub.2S, and HCl selectively permeable membrane such that at least one of CO.sub.2, H.sub.2S, and HCl is selectively transported through the membrane.

Flux Enhancement in Crossflow Membrane Filtration: Fouling and It's Minimization by Flow Reversal. Final Report

International Nuclear Information System (INIS)

Shamsuddin Ilias

2005-01-01

Fouling problems are perhaps the single most important reason for relatively slow acceptance of ultrafiltration in many areas of chemical and biological processing. To overcome the losses in permeate flux associated with concentration polarization and fouling in cross flow membrane filtration, we investigated the concept of flow reversal as a method to enhance membrane flux in ultrafiltration. Conceptually, flow reversal prevents the formation of stable hydrodynamic and concentration boundary layers at or near the membrane surface. Further more, periodic reversal of the flow direction of the feed stream at the membrane surface results in prevention and mitigation of membrane fouling. Consequently, these advantages are expected to enhance membrane flux significantly. A crossflow membrane filtration unit was designed and built to test the concept of periodic flow reversal for flux enhancement. The essential elements of the system include a crossflow hollow fiber membrane module integrated with a two-way valve to direct the feed flow directions. The two-way valve is controlled by a controller-timer for periodic reversal of flow of feed stream. Another important feature of the system is that with changing feed flow direction, the permeate flow direction is also changed to maintain countercurrent feed and permeate flows for enhanced mass transfer driving force (concentration difference). Three feed solutions (Bovine serum albumin (BSA), apple juice and citrus fruit pectin) were studied in crossflow membrane filtration. These solutes are well-known in membrane filtration for their fouling and concentration polarization potentials. Laboratory-scale tests on a hollow-fiber ultrafiltration membrane module using each of the feed solutes show that under flow reversal conditions, the permeate flux is significantly enhanced when compared with the conventional unidirectional flow. The flux enhancement is dramatic (by an order of magnitude) with increased feed concentration and

Investigation of Performance of SCN-1 Pure Glass as Sealant Used in SOFC

Energy Technology Data Exchange (ETDEWEB)

Liu, Wenning N.; Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.

2010-03-01

As its name implies, self-healing glass seal has the potential of restoring its mechanical properties upon being reheated to stack operating temperature, even when it has experienced some cooling induced damage/crack at room temperature. Such a self-healing feature is desirable for achieving high seal reliability during thermal cycling. On the other hand, self-healing glass is also characterized by its low mechanical stiffness and high creep rate at the typical operating temperature of SOFCs. Therefore, from a design’s perspective, it is important to know the long term geometric stability and thermal mechanical behaviors of the self-healing glass under the stack operating conditions. These predictive capabilities will guide the design and optimization of a reliable sealing system that potentially utilizes self-healing glass as well as other ceramic seal components in achieving the ultimate goal of SOFC. In this report, we focused on predicting the effects of various generic seal design parameters on the stresses in the seal. For this purpose, we take the test cell used in the leakage test for compliant glass seals conducted in PNNL as our initial modeling geometry. The effect of the ceramic stopper on the geometry stability of the self-healing glass sealants is studied first. Then we explored the effect of various interfaces such as stopper and glass, stopper and PEN, as well stopper and IC plate, on the geometry stability and reliability of glass during the operating and cooling processes.

Surgical Treatment of Pressure Ulcers with a Fibrin Sealant in Patients with Spinal Cord Injury: A Cost-Consequence Analysis.

Science.gov (United States)

Velasco, Jose Manuel Arévalo; Lozano, Virginia; Oyagüez, Itziar; Casado, Miguel Angel

2015-11-01

A comparative study was performed to evaluate the effectiveness and costs of a fibrin sealant (Tissucol Duo [known as Tisseel in the United States], Baxter International, Deerfield, Illinois) to improve postoperative outcomes in patients with spinal cord injury undergoing surgical treatment for pressure ulcers (PrUs). Between January and June 2011, 27 patients underwent surgical treatment for PrUs with the direct application of Tissucol Duo sprayed before closure. The costs and outcomes obtained in this cohort were compared with those obtained in a previous retrospective study where 71 patients underwent conventional surgery. Lower rates of hematoma-seroma were observed in the study group (3.7% vs 33.8%; P costs. The application of Tissucol Duo during surgical treatment of PrUs in patients with spinal cord injury has been shown to be effective in reducing postoperative complications and in shortening the duration of the hospital stay with a consequent savings in costs.

Safety and efficacy of distal perfusion catheterization to prevent limb ischemia after common femoral artery cannulation for extracorporeal membrane oxygenation

Energy Technology Data Exchange (ETDEWEB)

Jeon, Chang Ho; Seong, Nak Jong; Yoon, Chang Jin [Dept. of Radiology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

2016-06-15

The extracorporeal membrane oxygenation (ECMO) cannula has the potential for obstructing flow to the lower limb, thus causing severe ischemia and possible limb loss. We evaluated the safety and clinical efficacy of percutaneous distal perfusion catheterization in preventing limb ischemia. Between March 2013 and February 2015, 28 patients with distal perfusion catheterization after ECMO were included in this retrospective study. The technical success was evaluated by Doppler ultrasound at the popliteal level after saline injection via distal perfusion catheter. Clinical success was assessed when at least one of the following conditions was met: restoration of continuous peripheral limb oximetry value or presence of distal arterial pulse on Doppler ultrasound evaluation or resolution of early ischemic sign after connecting the catheter with ECMO. Twenty-six patients with early ischemia were successfully cannulated with a distal perfusion catheter (92.8%). Clinical success was achieved in 12/28 (42.8%) patients; 8/10 (80.0%) patients with survival duration exceeding 7 days and 4/18 (22.2%) patients with survival duration less than 7 days, respectively. A percutaneous distal perfusion catheter placement was a feasible tool with safety and efficacy in preventing lower limb ischemia for patients with prolonged common femoral arterial cannulation for ECMO.

Safety and efficacy of distal perfusion catheterization to prevent limb ischemia after common femoral artery cannulation for extracorporeal membrane oxygenation

International Nuclear Information System (INIS)

Jeon, Chang Ho; Seong, Nak Jong; Yoon, Chang Jin

2016-01-01

The extracorporeal membrane oxygenation (ECMO) cannula has the potential for obstructing flow to the lower limb, thus causing severe ischemia and possible limb loss. We evaluated the safety and clinical efficacy of percutaneous distal perfusion catheterization in preventing limb ischemia. Between March 2013 and February 2015, 28 patients with distal perfusion catheterization after ECMO were included in this retrospective study. The technical success was evaluated by Doppler ultrasound at the popliteal level after saline injection via distal perfusion catheter. Clinical success was assessed when at least one of the following conditions was met: restoration of continuous peripheral limb oximetry value or presence of distal arterial pulse on Doppler ultrasound evaluation or resolution of early ischemic sign after connecting the catheter with ECMO. Twenty-six patients with early ischemia were successfully cannulated with a distal perfusion catheter (92.8%). Clinical success was achieved in 12/28 (42.8%) patients; 8/10 (80.0%) patients with survival duration exceeding 7 days and 4/18 (22.2%) patients with survival duration less than 7 days, respectively. A percutaneous distal perfusion catheter placement was a feasible tool with safety and efficacy in preventing lower limb ischemia for patients with prolonged common femoral arterial cannulation for ECMO

Evaluation of a fissure sealant program as part of community-based teaching and training.

Science.gov (United States)

van Wyk, Philippus J; Kroon, Jeroen; White, John G

2004-01-01

Since 1995 the Department of Community Dentistry of the University of Pretoria has been involved in the rendering of mobile primary oral health care services to children in the Hammanskraal area of Gauteng, South Africa, as part of their students' community-based training. Mokonyama Primary School was identified as the first school where a primary oral health care service could be rendered. The objective of this study was to evaluate the impact (outcomes) of a fissure sealant program on the dentition status of the school children. Seven years after the implementation of the program, the dentition status of children at Mokonyama was compared with that of a comparable group of children from the same area who were not exposed to the program. The results showed that the decayed, missing, and filled teeth in the primary dentition (dmft) in the six-year-old group in Mokonyama (1.74) did not differ significantly from the dmft (1.43) of the control group (p = 0.49). The decayed, missing, and filled teeth in the permanent dentition (DMFT) of 0.59 for the fifteen-year-old group in Mokonyama, however, differed significantly (p = 0.0001) from the DMFT of the control group (2.38). Fifteen-year-old children in Mokonyama had 75.2 percent fewer caries than their counterparts in the control group.

Application of dynamic membranes in anaerobic membranes in anaerobic membrane bioreactor systems

NARCIS (Netherlands)

Erşahin, M.E.

2015-01-01

Anaerobic membrane bioreactors (AnMBRs) physically ensure biomass retention by the application of a membrane filtration process. With growing application experiences from aerobic membrane bioreactors (MBRs), the combination of membrane and anaerobic processes has received much attention and become

Multilayered sulphonated polysulfone/silica composite membranes for fuel cell applications

International Nuclear Information System (INIS)

Padmavathi, Rajangam; Karthikumar, Rajendhiran; Sangeetha, Dharmalingam

2012-01-01

Highlights: ► Multilayered membranes were fabricated with SPSu. ► Aminated polysulfone and silica were used as the layers in order to prevent the crossover of methanol. ► The methanol permeability and selectivity ratio proved a strong influence on DMFC application. ► The suitability of the multilayered membranes was studied in the lab made set-ups of PEMFC and DMFC. - Abstract: Polymer electrolyte membranes used in proton exchange membrane fuel cell (PEMFC) and direct methanol fuel cell (DMFC) suffer from low dimensional stability. Hence multilayered membranes using sulfonated polysulfone (SPSu) and silica (SiO 2 ) were fabricated to alter such properties. The introduction of an SiO 2 layer between two layers of SPSu to form the multilayered composite membrane enhanced its dimensional stability, but slightly lowered its proton conductivity when compared to the conventional SPSu/SiO 2 composite membrane. Additionally, higher water absorption, lower methanol permeability and higher flame retardancy were also observed in this newly fabricated multilayered membrane. The performance evaluation of the 2 wt% SiO 2 loaded multilayered membrane in DMFC showed a maximum power density of 86.25 mW cm −2 , which was higher than that obtained for Nafion 117 membrane (52.8 mW cm −2 ) in the same single cell test assembly. Hence, due to the enhanced dimensional stability, reduced methanol permeability and higher maximum power density, the SPSu/SiO 2 /SPSu multilayered membrane can be a viable and a promising candidate for use as an electrolyte membrane in DMFC applications, when compared to Nafion.

Electron paramagnetic resonance study of lipid and protein membrane components of erythrocytes oxidized with hydrogen peroxide

Energy Technology Data Exchange (ETDEWEB)

Mendanha, S.A.; Anjos, J.L.V.; Silva, A.H.M.; Alonso, A. [Instituto de Física, Universidade Federal de Goiás, Goiânia, GO (Brazil)

2012-04-05

Electron paramagnetic resonance (EPR) spectroscopy of spin labels was used to monitor membrane dynamic changes in erythrocytes subjected to oxidative stress with hydrogen peroxide (H{sub 2}O{sub 2}). The lipid spin label, 5-doxyl stearic acid, responded to dramatic reductions in membrane fluidity, which was correlated with increases in the protein content of the membrane. Membrane rigidity, associated with the binding of hemoglobin (Hb) to the erythrocyte membrane, was also indicated by a spin-labeled maleimide, 5-MSL, covalently bound to the sulfhydryl groups of membrane proteins. At 2% hematocrit, these alterations in membrane occurred at very low concentrations of H{sub 2}O{sub 2} (50 µM) after only 5 min of incubation at 37°C in azide phosphate buffer, pH 7.4. Lipid peroxidation, suggested by oxidative hemolysis and malondialdehyde formation, started at 300 µM H{sub 2}O{sub 2} (for incubation of 3 h), which is a concentration about six times higher than those detected with the probes. Ascorbic acid and α-tocopherol protected the membrane against lipoperoxidation, but did not prevent the binding of proteins to the erythrocyte membrane. Moreover, the antioxidant (+)-catechin, which also failed to prevent the cross-linking of cytoskeletal proteins with Hb, was very effective in protecting erythrocyte ghosts from lipid peroxidation induced by the Fenton reaction. This study also showed that EPR spectroscopy can be useful to assess the molecular dynamics of red blood cell membranes in both the lipid and protein domains and examine oxidation processes in a system that is so vulnerable to oxidation.

Development and characterization of glass-ceramic sealants in the (CaO-Al2O3-SiO2-B2O3) system for Solid Oxide Electrolyzer Cells

International Nuclear Information System (INIS)

Khedim, Hichem; Nonnet, Helene; Mear, Francois O.

2012-01-01

The efficiency of glass-ceramic sealants plays a crucial role in Solid Oxide Electrolyzer Cell performance and durability. In order to develop suitable sealants, operating around 800 degrees C, two parent glass compositions, CAS1B and CAS2B, from the CaO-Al 2 O 3 -SiO 2 -B 2 O 3 system were prepared and explored. The thermal and physicochemical properties of the glass ceramics and their crystallization behavior were investigated by HSM. DTA and XRD analyses. The microstructure and chemical compositions of the crystalline phases were investigated by microprobe analysis. Bonding characteristic as well as chemical interactions of the parent glass with yttria-stabilized zirconia (YSZ) electrolyte and ferritic steel-based interconnect (Crofere (R)) were also investigated. The preliminary results revealed the superiority of CAS2B glass for sealing application in SOECs. The effect of minor additions of V 2 O 5 , K 2 O and TiO 2 on the thermal properties was also studied and again demonstrated the advantages of the CAS2B glass composition. Examining the influence of heat treatment on the seal behavior showed that the choice of the heating rate is a compromise between delaying the crystallization process and delaying the viscosity drop. The thermal Expansion Coefficients (TEC) obtained for the selected glass ceramic are within the desired range after the heat treatment of crystallization. The crystallization kinetic parameters of the selected glass composition were also determined under non-isothermal conditions by means of differential thermal analysis (DTA) and using the formal theory of transformations for heterogeneous nucleation. (authors)

Method of detecting defects in ion exchange membranes of electrochemical cells by chemochromic sensors

Science.gov (United States)

Brooker, Robert Paul; Mohajeri, Nahid

2016-01-05

A method of detecting defects in membranes such as ion exchange membranes of electrochemical cells. The electrochemical cell includes an assembly having an anode side and a cathode side with the ion exchange membrane in between. In a configuration step a chemochromic sensor is placed above the cathode and flow isolation hardware lateral to the ion exchange membrane which prevents a flow of hydrogen (H.sub.2) between the cathode and anode side. The anode side is exposed to a first reactant fluid including hydrogen. The chemochromic sensor is examined after the exposing for a color change. A color change evidences the ion exchange membrane has at least one defect that permits H.sub.2 transmission therethrough.

Clinicians' preventive strategies for children and adolescents identified as at high risk of developing caries.

Science.gov (United States)

Sarmadi, Roxana; Gahnberg, Lars; Gabre, Pia

2011-05-01

Clinicians handle diagnosis and treatment planning of caries in different ways, and the underlying factors leading to management of risk and choice of treatment strategies are poorly understood. The aim of this study was to investigate dentists' and dental hygienists' choices of preventive strategies for children and adolescents identified as at high risk of developing caries. A sample of dental records from 432 of a total of 3372 children in a Swedish county identified as at high risk of developing caries, aged 3-19 years, was randomly selected for analysis in the study. Information of importance for the therapists' choice of caries management strategies were obtained from the dental records. The results showed that therapists considered tooth brushing instruction and fluoride treatment at the clinic to be of primary importance as treatment given in 60% of the cases, respectively. Fluoride treatment at home and diet counselling were both chosen in half of the cases. Fissure sealant therapy was used in 21% of the cases, and 15% of the patients did not receive any preventive treatment at all. The results also showed that girls more often received fluoride treatment, tooth brushing instruction and oral hygiene information than boys. In the majority of the children and adolescents, several preventive measures were given. The more background factors included in the risk assessment, the more preventive measures were given. The differences between the treatments given to girls and the boys need to be further investigated. © 2010 The Authors. International Journal of Paediatric Dentistry © 2010 BSPD, IAPD and Blackwell Publishing Ltd.

Fouling prevention of peptides from a tryptic whey hydrolysate during electromembrane processes by use of monovalent ion permselective membranes

OpenAIRE

Persico, Mathieu; Bazinet, Laurent

2017-01-01

Peptide adsorption occurring on conventional anion- and cation-exchange membranes is one of the main technological locks in electrodialysis (ED) for hydrolysate demineralization. Hence, the peptide fouling of monovalent anion (MAP) and monovalent cation (MCP) permselective membranes was studied and compared to conventional membranes (AMX-SB and CMX-SB). It appeared that the main peptide sequences responsible for fouling were TPEVDDEALEKFDK, VAGTWY and VLVLDTDYK for both anionic membranes; and...

Natural Organic Matter Removal and Fouling in a Low Pressure Hybrid Membrane Systems

Directory of Open Access Journals (Sweden)

Vedat Uyak

2014-01-01

Full Text Available The objective of this study was to investigate powdered activated carbon (PAC contribution to natural organic matter (NOM removal by a submerged MF and UF hybrid systems. It was found that filtration of surface waters by a bare MF and UF membranes removed negligible TOC; by contrast, significant amounts of TOC were removed when daily added PAC particles were predeposited on the membrane surfaces. These results support the assumption that the membranes surface properties and PAC layer structure might have considerably influential factor on NOM removal. Moreover, it was concluded that the dominant removal mechanism of hybrid membrane system is adsorption of NOM within PAC layer rather than size exclusion of NOM by both of membrane pores. Transmembrane pressure (TMP increases with PAC membrane systems support the view that PAC adsorption pretreatment will not prevent the development of membrane pressure; on the contrary, PAC particles themselves caused membrane fouling by blocking the entrance of pores of MF and UF membranes. Although all three source waters have similar HPI content, it appears that the PAC interaction with the entrance of membrane pores was responsible for offsetting the NOM fractional effects on membrane fouling for these source waters.

Challenges of Membrane Filtration for Produced Water Treatment in Offshore Oil & Gas Production

DEFF Research Database (Denmark)

Jepsen, Kasper Lund; Hansen, Leif; Mai, Christian

2016-01-01

struggling to their fundamental limit, therefore the membrane filtration technology turns to be a potential candidate for zero pollutant discharge. Membrane filtration technology suffers from the notorious fouling problem, where many methods for fouling prevention and removal are explored, the general idea...... is to guarantee that a relatively high permeability can be kept during filtration. Another crucial issue using membrane filtration technology is its huge energy consumption, for which there is little research has been done so far to systematically investigate and optimize the filtration system’s energy efficiency...

Development of advanced membrane process for treatment of radioactive liquid wastes

International Nuclear Information System (INIS)

Lee, Kune Woo; Choi, W. K.; Lee, J. W.; Jung, G. H.

2002-01-01

The followings were studied through the project entitled 'Development of advanced membrane process for treatment of radioactive liquid wastes'. 1. Surface modification technique of microfiltration membrane. Microporous hydrophobic polypropylene(PP) membrane were modified by radiation-induced grafting using hydrophilic monomers such as arylic acid(AAc), 2-hydroxyethyl methacrylate(HEMA) and styrenesulfonic acid(SSS). The effect of grafting conditions was investigated. Also, copolymeric condition of AAc and EGDMA for nylon membrane was studied. The structure of grafted PP membrane was examined by using FTIR-ATR spectroscopy, SEM and contact angle. The grafted membrane was characterized by measureing the water flux, the ion exchange capacity or the binding capacity of the metal ions. A study on the permeation behavior of simulated waste water containing oil emulsion and characterization of membrane fouling was carried out in the crossflow membrane filtration process using capillary type PP microfiltration membrane modified by radiation induced grafting of HEMA. The effects of various operating parameters were investigated. 2. Electrofiltration Technology. In this section, the process conditions for fouling prevention of membrane by evaluating the effects of operational parameters such as external electric field strength, crossflow velocity, transmembrane pressure, etc. on the permeate flux in electrofiltration were established and the process applicability for oil emulsion wastes containing surfactant using parallel plate type electrofiltration module was evaluated

Development of advanced membrane process for treatment of radioactive liquid wastes

Energy Technology Data Exchange (ETDEWEB)

Lee, Kune Woo; Choi, W. K.; Lee, J. W.; Jung, G. H

2002-01-01

The followings were studied through the project entitled 'Development of advanced membrane process for treatment of radioactive liquid wastes'. 1. Surface modification technique of microfiltration membrane. Microporous hydrophobic polypropylene(PP) membrane were modified by radiation-induced grafting using hydrophilic monomers such as arylic acid(AAc), 2-hydroxyethyl methacrylate(HEMA) and styrenesulfonic acid(SSS). The effect of grafting conditions was investigated. Also, copolymeric condition of AAc and EGDMA for nylon membrane was studied. The structure of grafted PP membrane was examined by using FTIR-ATR spectroscopy, SEM and contact angle. The grafted membrane was characterized by measureing the water flux, the ion exchange capacity or the binding capacity of the metal ions. A study on the permeation behavior of simulated waste water containing oil emulsion and characterization of membrane fouling was carried out in the crossflow membrane filtration process using capillary type PP microfiltration membrane modified by radiation induced grafting of HEMA. The effects of various operating parameters were investigated. 2. Electrofiltration Technology. In this section, the process conditions for fouling prevention of membrane by evaluating the effects of operational parameters such as external electric field strength, crossflow velocity, transmembrane pressure, etc. on the permeate flux in electrofiltration were established and the process applicability for oil emulsion wastes containing surfactant using parallel plate type electrofiltration module was evaluated.

Smart membranes for monitoring membrane based desalination processes

KAUST Repository

Laleg-Kirati, Taous-Meriem

2017-10-12

Various examples are related to smart membranes for monitoring membrane based process such as, e.g., membrane distillation processes. In one example, a membrane, includes a porous surface and a plurality of sensors (e.g., temperature, flow and/or impedance sensors) mounted on the porous surface. In another example, a membrane distillation (MD) process includes the membrane. Processing circuitry can be configured to monitor outputs of the plurality of sensors. The monitored outputs can be used to determine membrane degradation, membrane fouling, or to provide an indication of membrane replacement or cleaning. The sensors can also provide temperatures or temperature differentials across the porous surface, which can be used to improve modeling or control the MD process.

Osmotic versus conventional membrane bioreactors integrated with reverse osmosis for water reuse: Biological stability, membrane fouling, and contaminant removal.

Science.gov (United States)

Luo, Wenhai; Phan, Hop V; Xie, Ming; Hai, Faisal I; Price, William E; Elimelech, Menachem; Nghiem, Long D

2017-02-01

This study systematically compares the performance of osmotic membrane bioreactor - reverse osmosis (OMBR-RO) and conventional membrane bioreactor - reverse osmosis (MBR-RO) for advanced wastewater treatment and water reuse. Both systems achieved effective removal of bulk organic matter and nutrients, and almost complete removal of all 31 trace organic contaminants investigated. They both could produce high quality water suitable for recycling applications. During OMBR-RO operation, salinity build-up in the bioreactor reduced the water flux and negatively impacted the system biological treatment by altering biomass characteristics and microbial community structure. In addition, the elevated salinity also increased soluble microbial products and extracellular polymeric substances in the mixed liquor, which induced fouling of the forward osmosis (FO) membrane. Nevertheless, microbial analysis indicated that salinity stress resulted in the development of halotolerant bacteria, consequently sustaining biodegradation in the OMBR system. By contrast, biological performance was relatively stable throughout conventional MBR-RO operation. Compared to conventional MBR-RO, the FO process effectively prevented foulants from permeating into the draw solution, thereby significantly reducing fouling of the downstream RO membrane in OMBR-RO operation. Accumulation of organic matter, including humic- and protein-like substances, as well as inorganic salts in the MBR effluent resulted in severe RO membrane fouling in conventional MBR-RO operation. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Hydrophilic, bactericidal nanoheater-enabled reverse osmosis membranes to improve fouling resistance.

Science.gov (United States)

Ray, Jessica R; Tadepalli, Sirimuvva; Nergiz, Saide Z; Liu, Keng-Ku; You, Le; Tang, Yinjie; Singamaneni, Srikanth; Jun, Young-Shin

2015-06-03

Polyamide (PA) semipermeable membranes typically used for reverse osmosis water treatment processes are prone to fouling, which reduces the amount and quality of water produced. By synergistically coupling the photothermal and bactericidal properties of graphene oxide (GO) nanosheets, gold nanostars (AuNS), and hydrophilic polyethylene glycol (PEG) on PA reverse osmosis membrane surfaces, we have dramatically improved fouling resistance of these membranes. Batch fouling experiments from three classes of fouling are presented: mineral scaling (CaCO3 and CaSO4), organic fouling (humic acid), and biofouling (Escherichia coli). Systematic analyses and a variety of complementary techniques were used to elucidate fouling resistance mechanisms from each layer of modification on the membrane surface. Both mineral scaling and organic fouling were significantly reduced in PA-GO-AuNS-PEG membranes compared to other membranes. The PA-GO-AuNS-PEG membrane was also effective in killing all near-surface bacteria compared to PA membranes. In the PA-GO-AuNS-PEG membrane, the GO nanosheets act as templates for in situ AuNS growth, which then facilitated localized heating upon irradiation by an 808 nm laser inactivating bacteria on the membrane surface. Furthermore, AuNS in the membrane assisted PEG in preventing mineral scaling on the membrane surface. In flow-through flux and foulant rejection tests, PA-GO-AuNS-PEG membranes performed better than PA membranes in the presence of CaSO4 and humic acid model foulants. Therefore, the newly suggested membrane surface modifications will not only reduce fouling from RO feeds, but can improve overall membrane performance. Our innovative membrane design reported in this study can significantly extend the lifetime and water treatment efficacy of reverse osmosis membranes to alleviate escalating global water shortage from rising energy demands.

Support influence on the properties of the alumina ceramic membranes

International Nuclear Information System (INIS)

Clar, C.; Scian, A.N.; Aglietti, E.F.

2003-01-01

The ceramic substrates used as supports for the formation of a top layer membrane must meet several requirements.Some of them are: have an average pore size and a suitable surface rugosity to obtain a homogenous top layer preventing the penetration of the membrane precursor particles into the support pores.This work analyzes the performance of the three α-Al 2 O 3 supports, with different average pore sizes and surface textures, for the formation of a membrane top layer by the dipcoating technique from colloids in suspension of aluminum basic acetate and later thermal treatment at 1000degC.The pore size distribution of the supports, the support-membrane systems and the top layer membrane was obtained by the mercury intrusion porosimetry technique.The microstructural differences of the supports and the top layer thickness were observed by MEB.It could be observed that for numerous deposits the membrane layer pore size obtained is independent on the support used and that the thickness of the last layer is lower for the greater pore size supports.The possibility of an intermediate layer between the support and the top layer was considered in every case

Recent advances on polymeric membranes for membrane reactors

KAUST Repository

Buonomenna, M. G.; Choi, Seung Hak

2012-01-01

. The successful use of membranes in membrane reactors is primary the result of two developments concerning: (i) membrane materials and (ii) membrane structures. The selection of a suited material and preparation technique depends on the application the membrane

In an in-vitro model using human fetal membranes, 17-α hydroxyprogesterone caproate is not an optimal progestogen for inhibition of fetal membrane weakening.

Science.gov (United States)

Kumar, Deepak; Moore, Robert M; Mercer, Brian M; Mansour, Joseph M; Mesiano, Sam; Schatz, Frederick; Lockwood, Charles J; Moore, John J

2017-12-01

The progestogen 17-α hydroxyprogesterone caproate (17-OHPC) is 1 of only 2 agents recommended for clinical use in the prevention of spontaneous preterm delivery, and studies of its efficacy have been conflicting. We have developed an in-vitro model to study the fetal membrane weakening process that leads to rupture in preterm premature rupture of the fetal membranes (pPROM). Inflammation/infection associated with tumor necrosis factor-α (TNF-α) induction and decidual bleeding/abruption associated thrombin release are leading causes of preterm premature rupture of the fetal membranes. Both agents (TNF-α and thrombin) cause fetal membrane weakening in the model system. Furthermore, granulocyte-macrophage colony-stimulating factor (GM-CSF) is a critical intermediate for both TNF-α and thrombin-induced fetal membrane weakening. In a previous report, we demonstrated that 3 progestogens, progesterone, 17-alpha hydroxyprogesterone (17-OHP), and medroxyprogesterone acetate (MPA), each inhibit both TNF-α- and thrombin-induced fetal membrane weakening at 2 distinct points of the fetal membrane weakening pathway. Each block both the production of and the downstream action of the critical intermediate granulocyte-macrophage colony-stimulating factor. The objective of the study was to characterize the inhibitory effects of 17-OHPC on TNF-α- and thrombin-induced fetal membrane weakening in vitro. Full-thickness human fetal membrane fragments from uncomplicated term repeat cesarean deliveries were mounted in 2.5 cm Transwell inserts and cultured with/without 17-alpha hydroxyprogesterone caproate (10 -9 to 10 -7 M). After 24 hours, medium (supernatant) was removed and replaced with/without the addition of tumor necrosis factor-alpha (20 ng/mL) or thrombin (10 U/mL) or granulocyte-macrophage colony-stimulating factor (200 ng/mL). After 48 hours of culture, medium from the maternal side compartment of the model was assayed for granulocyte-macrophage colony

Evaluation of the potential anti-adhesion effect of the PVA/Gelatin membrane.

Science.gov (United States)

Bae, Sang-Ho; Son, So-Ra; Kumar Sakar, Swapan; Nguyen, Thi-Hiep; Kim, Shin-Woo; Min, Young-Ki; Lee, Byong-Taek

2014-05-01

A common and prevailing complication for patients with abdominal surgery is the peritoneal adhesion that follows during the post-operative recovery period. Biodegradable polymers have been suggested as a barrier to prevent the peritoneal adhesion. In this work, as a preventive method, PVA/Gelatin hydrogel-based membrane was investigated with various combinations of PVA and gelatin (50/50, 30/70/, and 10/90). Membranes were made by casting method using hot PVA-gelatin solution and the gelatin was cross-linked by exposing UV irradiation for 5 days to render stability of the produced sheathed form in the physiological environment. Physical crosslinking was chosen to avoid the problems of potential cytotoxic effect of chemical crosslinking. Their materials characterization and mechanical properties were evaluated by SEM surface characterization, hydrophilicity, biodegradation rate, and so forth. Cytocompatibility was observed by in vitro experiments with cell proliferation using confocal laser scanning microscopy and the MTT assay by L-929 mouse fibroblast cells. The fabricated PVA/Gel membranes were implanted between artificially defected cecum and peritoneal wall in rats and were sacrificed after 1 and 2 weeks post-operative to compare their tissue adhesion extents with that of control group where the defected surface was not separated by PVA/Gel membrane. The PVA/Gel membrane (10/90) significantly reduced the adhesion extent and showed to be a potential candidate for the anti-adhesion application. Copyright © 2013 Wiley Periodicals, Inc.

Recent advances on polymeric membranes for membrane reactors

KAUST Repository

Buonomenna, M. G.

2012-06-24

Membrane reactors are generally applied in high temperature reactions (>400 °C). In the field of fine chemical synthesis, however, much milder conditions are generally applicable and polymeric membranes were applied without their damage. The successful use of membranes in membrane reactors is primary the result of two developments concerning: (i) membrane materials and (ii) membrane structures. The selection of a suited material and preparation technique depends on the application the membrane is to be used in. In this chapter a review of up to date literature about polymers and configuration catalyst/ membranes used in some recent polymeric membrane reactors is given. The new emerging concept of polymeric microcapsules as catalytic microreactors has been proposed. © 2012 Bentham Science Publishers. All rights reserved.

Suppression of gold nanoparticle agglomeration and its separation via nylon membranes

Institute of Scientific and Technical Information of China (English)

Ayyavoo Jayalakshmi; In-Chul Kim; Young-Nam Kwon

2017-01-01

Use of ultraporous nylon membrane is one of the most widely employed techniques for removal of hard and soft nanoparticles in the semiconductor industry,and the accurate determination of membrane pore size is necessary in order to avoid manufacturing defects caused by contamination.The gold nanoparticle has several benefits for the evaluation of polymeric membranes;however,the nanoparticles agglomerate easily on the nylon membrane and make it difficult to evaluate the membrane precisely.The properties of 2-amino-2-hydroxymethyl-1,3-propanediol (ADP) ligand in gold nanoparticle solution were systematically investigated,and ADP was utilized for improved evaluation of the nylon membranes.Nylon membrane used in this study was prepared by phase inversion techniques.Ultrathin dense layer on top of the membrane surface and Darcy structures in the microporous membrane support were observed.The gold particle rejection was carried out at various pH values from 4 to 14 and higher rejection was observed at pH 4 and 8.The suppression of gold colloid agglomeration using ADP and monodispersity of gold colloids was also analyzed by confocal laser scanning microscopy (CLSM),transmission electron microscopy (TEM),and scanning electron microscopy (SEM).van der Waals interaction energy of the particles was reduced in the addition of ADP.The presence ofADP ligand in the gold solutions prevented the agglomeration of gold nanoparticles and reduced the adsorption of the particles on the nylon membrane surface,leading to precise evaluation of membrane pore sizes.

Recent Development of Nanocomposite Membranes for Vanadium Redox Flow Batteries

Directory of Open Access Journals (Sweden)

Sang-Ho Cha

2015-01-01

Full Text Available The vanadium redox flow battery (VRB has received considerable attention due to its long cycle life, flexible design, fast response time, deep-discharge capability, and low pollution emissions in large-scale energy storage. The key component of VRB is an ion exchange membrane that prevents cross mixing of the positive and negative electrolytes by separating two electrolyte solutions, while allowing the conduction of ions. This review summarizes efforts in developing nanocomposite membranes with reduced vanadium ion permeability and improved proton conductivity in order to achieve high performance and long life of VRB systems. Moreover, functionalized nanocomposite membranes will be reviewed for the development of next-generation materials to further improve the performance of VRB, focusing on their properties and performance of VRB.

Biaxial fatigue crack propagation behavior of perfluorosulfonic-acid membranes

Science.gov (United States)

Lin, Qiang; Shi, Shouwen; Wang, Lei; Chen, Xu; Chen, Gang

2018-04-01

Perfluorosulfonic-acid membranes have long been used as the typical electrolyte for polymer-electrolyte fuel cells, which not only transport proton and water but also serve as barriers to prevent reactants mixing. However, too often the structural integrity of perfluorosulfonic-acid membranes is impaired by membrane thinning or cracks/pinholes formation induced by mechanical and chemical degradations. Despite the increasing number of studies that report crack formation, such as crack size and shape, the underlying mechanism and driving forces have not been well explored. In this paper, the fatigue crack propagation behaviors of Nafion membranes subjected to biaxial loading conditions have been investigated. In particular, the fatigue crack growth rates of flat cracks in responses to different loading conditions are compared, and the impact of transverse stress on fatigue crack growth rate is clarified. In addition, the crack paths for slant cracks under both uniaxial and biaxial loading conditions are discussed, which are similar in geometry to those found after accelerated stress testing of fuel cells. The directions of initial crack propagation are calculated theoretically and compared with experimental observations, which are in good agreement. The findings reported here lays the foundation for understanding of mechanical failure of membranes.

Signos Vitales de los CDC–Los selladores dentales previenen las caries (Dental Sealants Prevent Cavities)

Centers for Disease Control (CDC) Podcasts

2016-10-18

Este podcast se basa en la edición de octubre del 2016 del informe Signos Vitales de los CDC. Los selladores dentales, que se aplican poco después de que les salgan las muelas permanentes a los niños, pueden protegerlos contra las caries hasta por nueve años. Aplicarles los selladores dentales a los niños de bajos ingresos en las escuelas podría ahorrar millones de dólares en costos de tratamientos.  Created: 10/18/2016 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 10/18/2016.

The Sur7 protein regulates plasma membrane organization and prevents intracellular cell wall growth in Candida albicans.

Science.gov (United States)

Alvarez, Francisco J; Douglas, Lois M; Rosebrock, Adam; Konopka, James B

2008-12-01

The Candida albicans plasma membrane plays important roles in cell growth and as a target for antifungal drugs. Analysis of Ca-Sur7 showed that this four transmembrane domain protein localized to stable punctate patches, similar to the plasma membrane subdomains known as eisosomes or MCC that were discovered in S. cerevisiae. The localization of Ca-Sur7 depended on sphingolipid synthesis. In contrast to S. cerevisiae, a C. albicans sur7Delta mutant displayed defects in endocytosis and morphogenesis. Septins and actin were mislocalized, and cell wall synthesis was very abnormal, including long projections of cell wall into the cytoplasm. Several phenotypes of the sur7Delta mutant are similar to the effects of inhibiting beta-glucan synthase, suggesting that the abnormal cell wall synthesis is related to activation of chitin synthase activity seen under stress conditions. These results expand the roles of eisosomes by demonstrating that Sur7 is needed for proper plasma membrane organization and cell wall synthesis. A conserved Cys motif in the first extracellular loop of fungal Sur7 proteins is similar to a characteristic motif of the claudin proteins that form tight junctions in animal cells, suggesting a common role for these tetraspanning membrane proteins in forming specialized plasma membrane domains.

The Sur7 Protein Regulates Plasma Membrane Organization and Prevents Intracellular Cell Wall Growth in Candida albicans

Science.gov (United States)

Alvarez, Francisco J.; Douglas, Lois M.; Rosebrock, Adam

2008-01-01

The Candida albicans plasma membrane plays important roles in cell growth and as a target for antifungal drugs. Analysis of Ca-Sur7 showed that this four transmembrane domain protein localized to stable punctate patches, similar to the plasma membrane subdomains known as eisosomes or MCC that were discovered in S. cerevisiae. The localization of Ca-Sur7 depended on sphingolipid synthesis. In contrast to S. cerevisiae, a C. albicans sur7Δ mutant displayed defects in endocytosis and morphogenesis. Septins and actin were mislocalized, and cell wall synthesis was very abnormal, including long projections of cell wall into the cytoplasm. Several phenotypes of the sur7Δ mutant are similar to the effects of inhibiting β-glucan synthase, suggesting that the abnormal cell wall synthesis is related to activation of chitin synthase activity seen under stress conditions. These results expand the roles of eisosomes by demonstrating that Sur7 is needed for proper plasma membrane organization and cell wall synthesis. A conserved Cys motif in the first extracellular loop of fungal Sur7 proteins is similar to a characteristic motif of the claudin proteins that form tight junctions in animal cells, suggesting a common role for these tetraspanning membrane proteins in forming specialized plasma membrane domains. PMID:18799621

Iron-complexed adsorptive membrane for As(V) species in water

International Nuclear Information System (INIS)

Shinde, Rakesh N.; Das, Sadananda; Acharya, R.; Rajurkar, N.S.; Pandey, Ashok K.

2012-01-01

Highlights: ► Functionalized membrane was prepared by graft polymerization in host membrane. ► Fe 3+ ions fixed in membrane made it selective for As(V) ions. ► As(V) preconcentrated selectively in membrane samples was quantified by INAA. ► As(V) in ground water sample was easily quantified in 2–3 ppb using membrane. ► Total inorganic arsenic could be quantified by oxidation of As(III) to As(V). - Abstract: Selective preconcentration of a target analyte in the solid phase is an effective route not only to enhance detection limit of the conventional analytical method but also for elimination of interfering matrix. An adsorptive membrane was developed for selective preconcentration and quantification of ultra-trace (ppb) amounts of As(V) present in a variety of aqueous samples. The precursor membrane was prepared by UV-initiator induced graft polymerization of sulphate and phosphate bearing monomers (1:1 mol proportion) in pores of the host microporous poly(propylene) membrane. Fe 3+ ions were loaded in the precursor membrane to make it selective for As(V) ions. The presence of phosphate functional groups prevent leaching of Fe 3+ ions from the membrane when it comes in contact with solution like seawater having high ionic strength. The optimized membrane was characterized in terms of its physical structure, chemical structure and experimental conditions affecting As(V) uptake in the membrane. The possibility of quantifying total preconcentration of As content was also explored by converting As(III) to As(V). To quantify As(V), the membrane samples were subjected to instrumental neutron activation analysis (INAA). The studies carried in the present work showed that quantification of inorganic arsenic species in natural water samples is easily possible in 2–3 ppb concentration range.

MStern Blotting–High Throughput Polyvinylidene Fluoride (PVDF) Membrane-Based Proteomic Sample Preparation for 96-Well Plates*

OpenAIRE

Berger, Sebastian T.; Ahmed, Saima; Muntel, Jan; Cuevas Polo, Nerea; Bachur, Richard; Kentsis, Alex; Steen, Judith; Steen, Hanno

2015-01-01

We describe a 96-well plate compatible membrane-based proteomic sample processing method, which enables the complete processing of 96 samples (or multiples thereof) within a single workday. This method uses a large-pore hydrophobic PVDF membrane that efficiently adsorbs proteins, resulting in fast liquid transfer through the membrane and significantly reduced sample processing times. Low liquid transfer speeds have prevented the useful 96-well plate implementation of FASP as a widely used mem...

Amnioinfusion for preterm rupture of membranes.

Science.gov (United States)

Hofmeyr, G J

2000-01-01

Preterm rupture of membranes places a fetus at risk of cord compression and amnionitis. Amnioinfusion aims to prevent or relieve umbilical cord compression by infusing a solution into the uterine cavity. The objective of this review was to assess the effects of amnioinfusion for preterm rupture of membranes on maternal and perinatal outcomes. The Cochrane Pregnancy and Childbirth Group trials register and the Cochrane Controlled Trials Register were searched. Randomised trials of amnioinfusion compared to no amnioinfusion in women with preterm rupture of membranes. Eligibility and trial quality were assessed by the reviewer. One trial of 66 women was included. It had some methodological flaws. No significant differences between amnioinfusion and no amnioinfusion were detected for caesarean section (relative risk 0.32, 95% confidence interval 0.07 to 1.40); low Apgar scores (relative risk 0.28, 95% confidence interval 0.03 to 2.33) or neonatal death (relative risk 0.55, 95% confidence interval 0.05 to 5.77). In the amnioinfusion group, the number of severe fetal heart rate decelerations per hour during the first stage of labour were reduced (weighted mean difference -1.20, 95% confidence interval -1.83 to -0.57). These outcomes are consistent with those found in the Cochrane review on amnioinfusion for cord compression. There is not enough evidence concerning the use of amnioinfusion for preterm rupture of membranes.

New insights into membrane-active action in plasma membrane of fungal hyphae by the lipopeptide antibiotic bacillomycin L.

Science.gov (United States)

Zhang, Bao; Dong, Chunjuan; Shang, Qingmao; Han, Yuzhu; Li, Pinglan

2013-09-01

Bacillomycin L, a natural iturinic lipopeptide produced by Bacillus amyloliquefaciens, is characterized by strong antifungal activities against a variety of agronomically important filamentous fungi including Rhizoctonia solani Kühn. Prior to this study, the role of membrane permeabilization in the antimicrobial activity of bacillomycin L against plant pathogenic fungi had not been investigated. To shed light on the mechanism of this antifungal activity, the permeabilization of R. solani hyphae by bacillomycin L was investigated and compared with that by amphotericin B, a polyene antibiotic which is thought to act primarily through membrane disruption. Our results derived from electron microscopy, various fluorescent techniques and gel retardation experiments revealed that the antifungal activity of bacillomycin L may be not solely a consequence of fungal membrane permeabilization, but related to the interaction of it with intracellular targets. Our findings provide more insights into the mode of action of bacillomycin L and other iturins, which could in turn help to develop new or improved antifungal formulations or result in novel strategies to prevent fungal spoilage. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

An observational cohort study on persistency of internal teat sealant residues in milk after calving in dairy cows.

Science.gov (United States)

Kabera, Fidèle; Dufour, Simon; Keefe, Greg; Roy, Jean-Philippe

2018-04-04

Our objectives were to evaluate the prevalence of quarters with an observable internal teat sealant (ITS) plug at first milking following calving and investigate persistency of ITS residues in milk after calving. An observational cohort study was carried out on 557 quarters of 156 cows treated with ITS in 6 farms in Quebec, Canada. The presence of an ITS plug at first milking and ITS residues in milk at each milking were observed by producers. The effects of various factors on the odds of observing an ITS plug and persistency of ITS residues in milk were studied using generalized logistic mixed and generalized negative binomial mixed models, respectively. Milk samples were taken on the day before dry-off and on 2 occasions after calving for bacterial identification to detect intramammary infection (IMI) using bacteriological culture followed by MALDI-TOF identification. The association between the absence of an ITS plug and the presence of new IMI was assessed using a mixed logistic regression model. Internal teat sealant plugs after calving were more often observed in rear quarters and in quarters receiving ITS alone at drying-off versus antimicrobial and ITS. We observed an average (standard deviation) persistency of 4.0 d (2.3 d). When an ITS plug was still present at first milking (83% of quarters), the elimination of ITS residues in milk after calving was significantly longer (4.5 d, on average) compared with 1.2 d when an ITS plug was absent. In cows with an ITS plug at calving, we observed a higher number of days of excretion in older cows. When a plug could not be observed, rear quarters, older cows, and cows with a long dry period duration excreted ITS residues for a significantly longer period. The lack of a significant association between the absence of a plug and the odds of new IMI at calving suggests that despite the loss of the plug, cows were still protected against new IMI. Although we were able to highlight some statistically significant risk

Wound healing and degradation of the fibrin sealant Beriplast P following partial liver resection in rabbits.

Science.gov (United States)

Kroez, Monika; Lang, Wiegand; Dickneite, Gerhard

2005-01-01

The objective of this study was to investigate the degradation kinetics of the fibrin sealant (FS) Beriplast P in an experimental liver surgery model in rabbits. A partial liver resection was performed in 21 rabbits, and the wound area covered with Beriplast P to ensure hemostasis. Wound healing of the resection sites was evaluated morphologically over 11 weeks. Degradation of the FS was evaluated by measuring the thickness of the remaining fibrin layer. Plasma samples were analyzed for antibodies against fibrinogen, albumin, thrombin, fibrin, and factor XIII. No postoperative hemorrhage was observed, indicating successful hemostasis throughout. The FS was degraded with a half-life of about 25 days postapplication and was completely replaced by granulation tissue within 9 weeks. The FS degradation and tissue development followed the general stages of wound healing: inflammation and resorption, proliferation, organization and production of collagen, maturation, and scarring. An immune reaction was elicited against the main four human proteins of the FS. The antibody titers peaked on day 14, with a gradual decrease thereafter. We conclude that the FS accomplished hemostasis, facilitated healing in accordance with natural processes, and was completely degraded over time. In humans, the reduced immunogenicity of the FS would potentially increase its degradation half-life.

Chronic Dosing with Membrane Sealant Poloxamer 188 NF Improves Respiratory Dysfunction in Dystrophic Mdx and Mdx/Utrophin-/- Mice.

Directory of Open Access Journals (Sweden)

Bruce E Markham

Full Text Available Poloxamer 188 NF (national formulary (NF grade of P-188 improves cardiac muscle function in the mdx mouse and golden retriever muscular dystrophy models. However in vivo effects on skeletal muscle have not been reported. We postulated that P-188 NF might protect diaphragm muscle membranes from contraction-induced injury in mdx and mdx/utrophin-/- (dko muscular dystrophy models. In the first study 7-month old mdx mice were treated for 22 weeks with subcutaneous (s.c. injections of saline or P-188 NF at 3 mg/Kg. In the second, dkos were treated with saline or P-188 NF (1 mg/Kg for 8 weeks beginning at age 3 weeks. Prednisone was the positive control in both studies. Respiratory function was monitored using unrestrained whole body plethysmography. P-188 NF treatment affected several respiratory parameters including tidal volume/BW and minute volume/BW in mdx mice. In the more severe dko model, P-188 NF (1 mg/Kg significantly slowed the decline in multiple respiratory parameters compared with saline-treated dko mice. Prednisone's effects were similar to those seen with P-188 NF. Diaphragms from P-188 NF or prednisone treated mdx and dko mice showed signs of muscle fiber protection including less centralized nuclei, less variation in fiber size, greater fiber density, and exhibited a decreased amount of collagen deposition. P-188 NF at 3 mg/Kg s.c. also improved parameters of systolic and diastolic function in mdx mouse hearts. These results suggest that P-188 NF may be useful in treating respiratory and cardiac dysfunction, the leading causes of death in Duchenne muscular dystrophy patients.

Membrane fouling mechanism of biofilm-membrane bioreactor (BF-MBR): Pore blocking model and membrane cleaning.

Science.gov (United States)

Zheng, Yi; Zhang, Wenxiang; Tang, Bing; Ding, Jie; Zheng, Yi; Zhang, Zhien

2018-02-01

Biofilm membrane bioreactor (BF-MBR) is considered as an important wastewater treatment technology that incorporates advantages of both biofilm and MBR process, as well as can alleviate membrane fouling, with respect to the conventional activated sludge MBR. But, to be efficient, it necessitates the establishment of proper methods for the assessment of membrane fouling. Four Hermia membrane blocking models were adopted to quantify and evaluate the membrane fouling of BF-MBR. The experiments were conducted with various operational conditions, including membrane types, agitation speeds and transmembrane pressure (TMP). Good agreement between cake formation model and experimental data was found, confirming the validity of the Hermia models for assessing the membrane fouling of BF-MBR and that cake layer deposits on membrane. Moreover, the influences of membrane types, agitation speeds and transmembrane pressure on the Hermia pore blocking coefficient of cake layer were investigated. In addition, the permeability recovery after membrane cleaning at various operational conditions was studied. This work confirms that, unlike conventional activated sludge MBR, BF-MBR possesses a low degree of membrane fouling and a higher membrane permeability recovery after cleaning. Copyright © 2017 Elsevier Ltd. All rights reserved.

Final environmental and regulatory assessment of using asphalt as a sealant in mine shafts

International Nuclear Information System (INIS)

1987-01-01

This report discusses the properties of asphalt, the current regulatory status governing asphalt and future regulatory implications which may be pertinent in using asphalt as a waterproof shaft sealant. An understanding of the inherent organic composition of asphalt, an increase in the number of health and environmental research publications conducted on asphalt and an examination of the apparent trend of regulatory agencies toward more stringent environmental regulation governing the use of organic materials suggests asphalt could become regulated at a future time. This would only occur, however, if asphalt was found to conform to the present regulatory definitions of pollutants, contaminants or hazardous substances or if asphalt was included on a regulated substance list. In this regard, the study points out that asphalt contains very low levels of hazardous poly-nuclear aromatics (PNA's). These levels are significantly lower than the levels present in coal tars, a substance known to contain high levels of hazardous PNA's. Asphalt, however, has the inherent potential of producing higher concentrations of PNA's if the adverse condition of cracking should occur during the refinery production stage or on-site preparation of the asphalt. Also, unless existing control technology is applied, emission levels of sulfur dioxide, carbon monoxide, particulates and volatile organic carbons from the on-site preparation facilities could approach the permissible health standard levels of EPA. The study indicates, however, that available literature is limited on these issues

Influence of Erythrocyte Membrane Stability in Atherosclerosis.

Science.gov (United States)

da Silva Garrote-Filho, Mario; Bernardino-Neto, Morun; Penha-Silva, Nilson

2017-04-01

The purpose of this study is to show how an excess of cholesterol in the erythrocyte membrane contributes stochastically to the progression of atherosclerosis, leading to damage in blood rheology and O 2 transport, deposition of cholesterol (from trapped erythrocytes) in an area of intraplaque hemorrhage, and local exacerbation of oxidative stress. Cholesterol contained in the membrane of erythrocytes trapped in an intraplaque hemorrhage contributes to the growth of the necrotic nucleus. There is even a relationship between the amount of cholesterol in the erythrocyte membrane and the severity of atherosclerosis. In addition, the volume variability among erythrocytes, measured by RDW, is predictive of a worsening of this disease. Erythrocytes contribute to the development of atherosclerosis in several ways, especially when trapped in intraplate hemorrhage. These erythrocytes are oxidized and phagocytosed by macrophages. The cholesterol present in the membrane of these erythrocytes subsequently contributes to the growth of the atheroma plaque. In addition, when they rupture, erythrocytes release hemoglobin, which leads to the generation of free radicals. Finally, increased RDW may predict the worsening of atherosclerosis, due to the effects of inflammation and oxidative stress on erythropoiesis and erythrocyte volume. A better understanding of erythrocyte participation in atherosclerosis may contribute to the improvement of the prevention and treatment strategies of this disease.

Assessing the utility of bipolar membranes for use in photoelectrochemical water-splitting cells.

Science.gov (United States)

Vargas-Barbosa, Nella M; Geise, Geoffrey M; Hickner, Michael A; Mallouk, Thomas E

2014-11-01

Membranes are important in water-splitting solar cells because they prevent crossover of hydrogen and oxygen. Here, bipolar membranes (BPMs) were tested as separators in water electrolysis cells. Steady-state membrane and solution resistances, electrode overpotentials, and pH gradients were measured at current densities relevant to solar photoelectrolysis. Under forward bias conditions, electrodialysis of phosphate buffer ions creates a pH gradient across a BPM. Under reverse bias, the BPM can maintain a constant buffer pH on both sides of the cell, but a large membrane potential develops. Thus, the BPM does not present a viable solution for electrolysis in buffered electrolytes. However, the membrane potential is minimized when the anode and cathode compartments of the cell contain strongly basic and acidic electrolytes, respectively. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synaptotoxicity of Alzheimer beta amyloid can be explained by its membrane perforating property.

Directory of Open Access Journals (Sweden)

Fernando J Sepulveda

Full Text Available The mechanisms that induce Alzheimer's disease (AD are largely unknown thereby deterring the development of disease-modifying therapies. One working hypothesis of AD is that Abeta excess disrupts membranes causing pore formation leading to alterations in ionic homeostasis. However, it is largely unknown if this also occurs in native brain neuronal membranes. Here we show that similar to other pore forming toxins, Abeta induces perforation of neuronal membranes causing an increase in membrane conductance, intracellular calcium and ethidium bromide influx. These data reveal that the target of Abeta is not another membrane protein, but that Abeta itself is the cellular target thereby explaining the failure of current therapies to interfere with the course of AD. We propose that this novel effect of Abeta could be useful for the discovery of anti AD drugs capable of blocking these "Abeta perforates". In addition, we demonstrate that peptides that block Abeta neurotoxicity also slow or prevent the membrane-perforating action of Abeta.

Patents on Membranes Based on Non-Fluorinated Polymers for Vanadium Redox Flow Batteries.

Science.gov (United States)

Choi, So-Won; Kim, Tae-Ho; Cha, Sang-Ho

2017-07-10

Vanadium redox flow batteries (VRFBs) have received considerable attention as large-scale electrochemical energy storage systems. In particular, VRFBs offer a higher power and energy density than other RFBs and mitigate undesirable performance fading, such as inevitable ion crossover, because of the unique advantage that only the vanadium ion is employed as the active species in the two electrolytes. The key constituent of VRFBs is a separator to conduct protons and prevent cross-mixing of the positive and negative electrolytes. For this purpose, ion exchange membranes like sulfonated polymer membranes can be used. Although this type of membrane does not have ion exchange groups, it can achieve an ion exchange capacity by the formation of pores. This review highlights the patents on the preparation of non-fluorinated membranes (sulfonated aromatic polymer membranes and porous membranes) as alternatives to high-cost perfluorinated polymers and their VRFB performance. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Anaplasma phagocytophilum inhibits human neutrophil apoptosis via upregulation of bfl-1, maintenance of mitochondrial membrane potential and prevention of caspase 3 activation.

Science.gov (United States)

Ge, Yan; Yoshiie, Kiyotaka; Kuribayashi, Futoshi; Lin, Mingqun; Rikihisa, Yasuko

2005-01-01

The inhibition of neutrophil apoptosis plays a central role in human granulocytic anaplasmosis. Intracellular signalling pathways through which the obligatory intracellular bacterium Anaplasma phagocytophilum inhibits the spontaneous apoptosis of human peripheral blood neutrophils were investigated. bfl-1 mRNA levels in uninfected neutrophils after 12 h in culture were reduced to approximately 5-25% of 0 h levels, but remained high in infected neutrophils. The eukaryotic RNA synthesis inhibitor, actinomycin D, prevented the maintenance of bfl-1 mRNA levels by A. phagocytophilum. Differences in mcl-1, bax, bcl-w, bad or bak mRNA levels in infected versus uninfected neutrophils were not remarkable. By using mitochondrial fluorescent dyes, Mitotracker Red and JC-1, it was found that most uninfected neutrophils lost mitochondrial membrane potential after 10-12 h incubation, whereas A. phagocytophilum-infected neutrophils maintained high membrane potential. Caspase 3 activity and the degree of apoptosis were lower in dose-dependent manner in A. phagocytophilum-infected neutrophils at 16 h post infection, as compared to uninfected neutrophils. Anti-active caspase 3 antibody labelling showed less positively stained population in infected neutrophils compared to those in uninfected neutrophils after 12 h incubation. These results suggest that A. phagocytophilum inhibits human neutrophil apoptosis via transcriptional upregulation of bfl-1 and inhibition of mitochondria-mediated activation of caspase 3.

β-arrestin regulates estradiol membrane-initiated signaling in hypothalamic neurons.

Directory of Open Access Journals (Sweden)

Angela M Wong

Full Text Available Estradiol (E2 action in the nervous system is the result of both direct nuclear and membrane-initiated signaling (EMS. E2 regulates membrane estrogen receptor-α (ERα levels through opposing mechanisms of EMS-mediated trafficking and internalization. While ß-arrestin-mediated mERα internalization has been described in the cortex, a role of ß-arrestin in EMS, which underlies multiple physiological processes, remains undefined. In the arcuate nucleus of the hypothalamus (ARH, membrane-initiated E2 signaling modulates lordosis behavior, a measure of female sexually receptivity. To better understand EMS and regulation of ERα membrane levels, we examined the role of ß-arrestin, a molecule associated with internalization following agonist stimulation. In the present study, we used an immortalized neuronal cell line derived from embryonic hypothalamic neurons, the N-38 line, to examine whether ß-arrestins mediate internalization of mERα. β-arrestin-1 (Arrb1 was found in the ARH and in N-38 neurons. In vitro, E2 increased trafficking and internalization of full-length ERα and ERαΔ4, an alternatively spliced isoform of ERα, which predominates in the membrane. Treatment with E2 also increased phosphorylation of extracellular-signal regulated kinases 1/2 (ERK1/2 in N-38 neurons. Arrb1 siRNA knockdown prevented E2-induced ERαΔ4 internalization and ERK1/2 phosphorylation. In vivo, microinfusions of Arrb1 antisense oligodeoxynucleotides (ODN into female rat ARH knocked down Arrb1 and prevented estradiol benzoate-induced lordosis behavior compared with nonsense scrambled ODN (lordosis quotient: 3 ± 2.1 vs. 85.0 ± 6.0; p < 0.0001. These results indicate a role for Arrb1 in both EMS and internalization of mERα, which are required for the E2-induction of female sexual receptivity.

Calcium, membranes and accumulation of alkaloids in plants

International Nuclear Information System (INIS)

Lovkova, M.Ya.; Buzuk, G.N.; Grinkevich, N.I.

1983-01-01

Ca 2+ effect upon metabolism of aporphines and protopines has been studied in Glaucium flavun, which alkaloids are of an essential interest for the medicine practice. It has been shown that calcium produces the inhibiting effect both on catabolitic splitting and metabolism of glaucine and protopine. It has been anticipated that calcuium introduced into an expert plant stabilizes membranes of intracellular structures and prevents 14 C alkaloid entering from an environment to metabolically active cell compartments, which contain ferments realizing transformations of the above compounds. The level of membrane permeability is probably the main mechanism, through which a control of metabolism processes occurs, and hence, a control of alkaloid accumulation processes under in vivo conditions

Membrane dynamics

DEFF Research Database (Denmark)

Bendix, Pól Martin

2015-01-01

Current topics include membrane-protein interactions with regard to membrane deformation or curvature sensing by BAR domains. Also, we study the dynamics of membrane tubes of both cells and simple model membrane tubes. Finally, we study membrane phase behavior which has important implications...... for the lateral organization of membranes as wells as for physical properties like bending, permeability and elasticity...

Inverse colloidal crystal membranes for hydrophobic interaction membrane chromatography.

Science.gov (United States)

Vu, Anh T; Wang, Xinying; Wickramasinghe, S Ranil; Yu, Bing; Yuan, Hua; Cong, Hailin; Luo, Yongli; Tang, Jianguo

2015-08-01

Hydrophobic interaction membrane chromatography has gained interest due to its excellent performance in the purification of humanized monoclonal antibodies. The membrane material used in hydrophobic interaction membrane chromatography has typically been commercially available polyvinylidene fluoride. In this contribution, newly developed inverse colloidal crystal membranes that have uniform pores, high porosity and, therefore, high surface area for protein binding are used as hydrophobic interaction membrane chromatography membranes for humanized monoclonal antibody immunoglobulin G purification. The capacity of the inverse colloidal crystal membranes developed here is up to ten times greater than commercially available polyvinylidene fluoride membranes with a similar pore size. This work highlights the importance of developing uniform pore size high porosity membranes in order to maximize the capacity of hydrophobic interaction membrane chromatography. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Efficacy of a Self-expanding Tract Sealant Device in the Reduction of Pneumothorax and Chest Tube Placement Rates After Percutaneous Lung Biopsy: A Matched Controlled Study Using Propensity Score Analysis.

Science.gov (United States)

Ahrar, Judy U; Gupta, Sanjay; Ensor, Joe E; Mahvash, Armeen; Sabir, Sharjeel H; Steele, Joseph R; McRae, Stephen E; Avritscher, Rony; Huang, Steven Y; Odisio, Bruno C; Murthy, Ravi; Ahrar, Kamran; Wallace, Michael J; Tam, Alda L

2017-02-01

To evaluate the use of a self-expanding tract sealant device (BioSentry™) on the rates of pneumothorax and chest tube insertion after percutaneous lung biopsy. In this retrospective study, we compared 318 patients who received BioSentry™ during percutaneous lung biopsy (treated group) with 1956 patients who did not (control group). Patient-, lesion-, and procedure-specific variables, and pneumothorax and chest tube insertion rates were recorded. To adjust for potential selection bias, patients in the treated group were matched 1:1 to patients in the control group using propensity score matching based on the above-mentioned variables. Patients were considered a match if the absolute difference in their propensity scores was ≤equal to 0.02. Before matching, the pneumothorax and chest tube rates were 24.5 and 13.1% in the control group, and 21.1 and 8.5% in the treated group, respectively. Using propensity scores, a match was found for 317 patients in the treatment group. Chi-square contingency matched pair analysis showed the treated group had significantly lower pneumothorax (20.8 vs. 32.8%; p = 0.001) and chest tube (8.2 vs. 20.8%; p 30 cases of both treatment and control cases demonstrated similar findings: the treated group had significantly lower pneumothorax (17.6 vs. 30.2%; p = 0.002) and chest tube (7.2 vs. 18%; p = 0.001) rates. The self-expanding tract sealant device significantly reduced the pneumothorax rate, and more importantly, the chest tube placement rate after percutaneous lung biopsy.

Smart membranes for monitoring membrane based desalination processes

KAUST Repository

Laleg-Kirati, Taous-Meriem; Karam, Ayman M.

2017-01-01

Various examples are related to smart membranes for monitoring membrane based process such as, e.g., membrane distillation processes. In one example, a membrane, includes a porous surface and a plurality of sensors (e.g., temperature, flow and

Silver and gold nanoparticle coated membranes applied to protein dot blots

International Nuclear Information System (INIS)

Xie, F.; Drozdowicz-Tomsia, K.; Shtoyko, T.; Goldys, E. M.

2011-01-01

Detection and identification of low abundance biomarker proteins is frequently based on various types of membrane-based devices. Lowering of the protein detection limits is vital in commercial applications such as lateral flow assays and in Western blots widely used in proteomics. These currently suffer from insufficient detection sensitivity and low retention for small 2–5 kDa proteins. In this study, we report the deposition of two types of metal nanoparticles: gold colloids (50–95 nm diameter) and silver fractals onto a range of commonly used types of membranes including polyvinylidene fluoride (PVDF). Due to strong affinity of proteins to noble metals, such modified membranes have the potential to effectively capture trace proteins preventing their loss. The membranes modified by metal particles were characterized optically and by SEM. The membrane performance in protein dot blots was evaluated using the protein—fluorophore conjugates Deep Purple-bovine serum albumin and fluorescein—human serum albumin. We found that the metal nanoparticles increase light extinction by metals, which is balanced by increased fluorescence, so that the effective fluorescence signal is unchanged. This feature combined with the capture of proteins by the nanoparticles embedded in the membrane increases the detection limit of membrane assays.

Biomimetic membranes and methods of making biomimetic membranes

Science.gov (United States)

Rempe, Susan; Brinker, Jeffrey C.; Rogers, David Michael; Jiang, Ying-Bing; Yang, Shaorong

2016-11-08

The present disclosure is directed to biomimetic membranes and methods of manufacturing such membranes that include structural features that mimic the structures of cellular membrane channels and produce membrane designs capable of high selectivity and high permeability or adsorptivity. The membrane structure, material and chemistry can be selected to perform liquid separations, gas separation and capture, ion transport and adsorption for a variety of applications.

Gel layer formation on membranes in Membrane Bioreactors

NARCIS (Netherlands)

Van den Brink, P.F.H.

2014-01-01

The widespread application of membrane bioreactors (MBRs) for municipal wastewater treatment is hampered by membrane fouling. Fouling increases energy demand, reduces process performance and creates the need for more frequent (chemical) membrane cleaning or replacement. Membrane fouling in MBRs is

Cost-effectiveness of preventing dental caries and full mouth dental reconstructions among Alaska Native children in the Yukon–Kuskokwim delta region of Alaska

Science.gov (United States)

Atkins, Charisma Y.; Thomas, Timothy K.; Lenaker, Dane; Day, Gretchen M.; Hennessy, Thomas W.; Meltzer, Martin I.

2016-01-01

Objective We conducted a cost-effectiveness analysis of five specific dental interventions to help guide resource allocation. Methods We developed a spreadsheet-based tool, from the healthcare payer perspective, to evaluate the cost effectiveness of specific dental interventions that are currently used among Alaska Native children (6-60 months). Interventions included: water fluoridation, dental sealants, fluoride varnish, tooth brushing with fluoride toothpaste, and conducting initial dental exams on children caries treatments completed by a dental provider in the dental chair, while 161 children received FMDRs completed by a dental surgeon in an operating room. The average cost of treating dental caries in the dental chair was $1,467 (~258,000 per year); while the cost of treating FMDRs was $9,349 (~1.5 million per year). All interventions were shown to prevent caries and FMDRs; however tooth brushing prevented the greatest number of caries at minimum and maximum effectiveness with 1,433 and 1,910, respectively. Tooth brushing also prevented the greatest number of FMDRs (159 and 211) at minimum and maximum effectiveness. Conclusions All of the dental interventions evaluated were shown to produce cost savings. However, the level of that cost saving is dependent on the intervention chosen. PMID:26990678

Model-Based Control of a Continuous Coating Line for Proton Exchange Membrane Fuel Cell Electrode Assembly

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Vikram Devaraj

2015-01-01

Full Text Available The most expensive component of a fuel cell is the membrane electrode assembly (MEA, which consists of an ionomer membrane coated with catalyst material. Best-performing MEAs are currently fabricated by depositing and drying liquid catalyst ink on the membrane; however, this process is limited to individual preparation by hand due to the membrane’s rapid water absorption that leads to shape deformation and coating defects. A continuous coating line can reduce the cost and time needed to fabricate the MEA, incentivizing the commercialization and widespread adoption of fuel cells. A pilot-scale membrane coating line was designed for such a task and is described in this paper. Accurate process control is necessary to prevent manufacturing defects from occurring in the coating line. A linear-quadratic-Gaussian (LQG controller was developed based on a physics-based model of the coating process to optimally control the temperature and humidity of the drying zones. The process controller was implemented in the pilot-scale coating line proving effective in preventing defects.

Peptide-modified PELCL electrospun membranes for regulation of vascular endothelial cells

Energy Technology Data Exchange (ETDEWEB)

Zhou, Fang [School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072 (China); Jia, Xiaoling [Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083 (China); Yang, Yang [School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072 (China); Yang, Qingmao; Gao, Chao [Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083 (China); Zhao, Yunhui [School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072 (China); Fan, Yubo, E-mail: yubofan@buaa.edu.cn [Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083 (China); National Research Center for Rehabilitation Technical Aids, Beijing 100176 (China); Yuan, Xiaoyan, E-mail: yuanxy@tju.edu.cn [School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072 (China)

2016-11-01

The efficiency of biomaterials used in small vascular repair depends greatly on their ability to interact with vascular endothelial cells (VECs). Rapid endothelialization of the vascular grafts is a promising way to prevent thrombosis and intimal hyperplasia. In this work, modification of electrospun membranes of poly(ethylene glycol)-b-poly(L-lactide-co-ε-caprolactone) (PELCL) by three different peptides for regulation of VECs were studied in order to obtain ideal bioactive biomaterials as small diameter vascular grafts. QK (a mimetic peptide to vascular endothelial growth factor), Arg-Glu-Asp-Val (REDV, a specific adhesive peptide to VECs) and Val-Ala-Pro-Gly (VAPG, a specific adhesive peptide to vascular smooth muscle cells) were investigated. Surface properties of the modified membranes and the response of VECs were verified. It was found that protein adsorption and platelet adhesion were effectively suppressed with the introduction of QK, REDV or VAPG peptides on the PELCL electrospun membranes. Both QK- and REDV-modified electrospun membranes could accelerate the proliferation of VECs in the first 9 days, and the QK-modified electrospun membrane promoted cell proliferation more significantly than the REDV-modified one. The REDV-modified PELCL membrane was the most favorable for VECs adhesion than QK- and VAPG-modified membranes. It was suggested that QK- or REDV-modified PELCL electrospun membranes may have great potential applications in cardiovascular biomaterials for rapid endothelialization in situ. - Highlights: • A series of peptide-modified PELCL electrospun membranes were prepared. • Hemocompatibility of the membranes was greatly improved by the modification. • QK-modified PELCL membrane promoted VECs proliferation more significantly. • REDV-modified PELCL membrane was the most favorable for VEC adhesion.

Peptide-modified PELCL electrospun membranes for regulation of vascular endothelial cells

International Nuclear Information System (INIS)

Zhou, Fang; Jia, Xiaoling; Yang, Yang; Yang, Qingmao; Gao, Chao; Zhao, Yunhui; Fan, Yubo; Yuan, Xiaoyan

2016-01-01

The efficiency of biomaterials used in small vascular repair depends greatly on their ability to interact with vascular endothelial cells (VECs). Rapid endothelialization of the vascular grafts is a promising way to prevent thrombosis and intimal hyperplasia. In this work, modification of electrospun membranes of poly(ethylene glycol)-b-poly(L-lactide-co-ε-caprolactone) (PELCL) by three different peptides for regulation of VECs were studied in order to obtain ideal bioactive biomaterials as small diameter vascular grafts. QK (a mimetic peptide to vascular endothelial growth factor), Arg-Glu-Asp-Val (REDV, a specific adhesive peptide to VECs) and Val-Ala-Pro-Gly (VAPG, a specific adhesive peptide to vascular smooth muscle cells) were investigated. Surface properties of the modified membranes and the response of VECs were verified. It was found that protein adsorption and platelet adhesion were effectively suppressed with the introduction of QK, REDV or VAPG peptides on the PELCL electrospun membranes. Both QK- and REDV-modified electrospun membranes could accelerate the proliferation of VECs in the first 9 days, and the QK-modified electrospun membrane promoted cell proliferation more significantly than the REDV-modified one. The REDV-modified PELCL membrane was the most favorable for VECs adhesion than QK- and VAPG-modified membranes. It was suggested that QK- or REDV-modified PELCL electrospun membranes may have great potential applications in cardiovascular biomaterials for rapid endothelialization in situ. - Highlights: • A series of peptide-modified PELCL electrospun membranes were prepared. • Hemocompatibility of the membranes was greatly improved by the modification. • QK-modified PELCL membrane promoted VECs proliferation more significantly. • REDV-modified PELCL membrane was the most favorable for VEC adhesion.

Nanodisc-solubilized membrane protein library reflects the membrane proteome.

Science.gov (United States)

Marty, Michael T; Wilcox, Kyle C; Klein, William L; Sligar, Stephen G

2013-05-01

The isolation and identification of unknown membrane proteins offers the prospect of discovering new pharmaceutical targets and identifying key biochemical receptors. However, interactions between membrane protein targets and soluble ligands are difficult to study in vitro due to the insolubility of membrane proteins in non-detergent systems. Nanodiscs, nanoscale discoidal lipid bilayers encircled by a membrane scaffold protein belt, have proven to be an effective platform to solubilize membrane proteins and have been used to study a wide variety of purified membrane proteins. This report details the incorporation of an unbiased population of membrane proteins from Escherichia coli membranes into Nanodiscs. This solubilized membrane protein library (SMPL) forms a soluble in vitro model of the membrane proteome. Since Nanodiscs contain isolated proteins or small complexes, the SMPL is an ideal platform for interactomics studies and pull-down assays of membrane proteins. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the protein population before and after formation of the Nanodisc library indicates that a large percentage of the proteins are incorporated into the library. Proteomic identification of several prominent bands demonstrates the successful incorporation of outer and inner membrane proteins into the Nanodisc library.

Cyanoacrylate Skin Microsealant for Preventing Surgical Site Infection after Vascular Surgery : A Discontinued Randomized Clinical Trial

NARCIS (Netherlands)

Vierhout, Bastiaan P.; Ott, Alewijn; Reijnen, Michel M. P. J.; Oskam, Jacques; Ott, Alewijn; van den Dungen, Jan J. A. M.; Zeebregts, Clark J.

Background: Surgical site infections (SSI) after vascular surgery are related to substantial morbidity. Restriction of bacterial access to the site of surgery with a cyanoacrylate sealant is a new concept. We performed a randomized clinical trial to assess the effect of the sealing of skin with a

In vitro evaluation of electrospun chitosan mats crosslinked with genipin as guided tissue regeneration barrier membranes

Science.gov (United States)

Norowski, Peter Andrew, Jr.

Guided tissue regeneration (GTR) is a surgical technique commonly used to exclude bacteria and soft tissues from bone graft sites in oral/maxillofacial bone graft sites by using a barrier membrane to maintain the graft contour and space. Current clinical barrier membrane materials based on expanded polytetrafluoroethylene (ePTFE) and bovine type 1 collagen are non-ideal and experience a number of disadvantages including membrane exposure, bacterial colonization/biofilm formation and premature degradation, all of which result in increased surgical intervention and poor bone regeneration. These materials do not actively participate in tissue regeneration, however bioactive materials, such as chitosan, may provide advantages such as the ability to stimulate wound healing and de novo bone formation. Our hypothesis is that electrospun chitosan GTR membranes will support cell attachment and growth but prevent cell infiltration/penetration of membrane, demonstrate in vitro degradation predictive of 4--6 month in vivo functionality, and will deliver antibiotics locally to prevent/inhibit periopathogenic complications. To test this hypothesis a series of chitosan membranes were electrospun, in the presence or absence of genipin, a natural crosslinking agent, at concentrations of 5 and 10 mM. These membranes were characterized by scanning electron microscopy, tensile testing, suture pullout testing, Fourier transform infrared spectroscopy, X-ray diffraction, and gel permeation chromatography, and in vitro biodegradation for diameter/morphology of fibers, membrane strengths, degree of crosslinking, crystallinity, molecular weight, and degradation kinetics, respectively. Cytocompability of membranes was evaluated in osteoblastic, fibroblastic and monocyte cultures. The activity of minocycline loaded and released from the membranes was determined in zone of inhibition tests using P. gingivalis microbe. The results demonstrated that genipin crosslinking extended the in vitro

Androgen Receptor Localizes to Plasma Membrane by Binding to Caveolin-1 in Mouse Sertoli Cells

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Qiong Deng

2017-01-01

Full Text Available The nonclassical androgen signaling pathway translates signals into alterations in cellular function within minutes, and this action is proposed to be mediated by an androgen receptor (AR localized to the plasma membrane. This study was designed to determine the mechanism underlying the membrane association of androgen receptor in TM4 cells, a mouse Sertoli cell line. Western blot analysis indicated testosterone-induced AR translocation to the cell membrane. Data from coimmunoprecipitation indicated that AR is associated with caveolin-1, and testosterone enhanced this association. Knockdown of caveolin-1 by shRNA decreased the amount of AR localized to membrane fraction and prevented AR membrane trafficking after being exposed to testosterone at physiological concentration. The palmitoylation inhibitor 2-bromopalmitate decreased AR membrane localization in basal condition and completely blocked testosterone-induced AR translocation to membrane fraction. These data suggested that AR localized to membrane fraction by binding with caveolin-1 through palmitoylation of the cysteine residue. This study provided a new evidence for AR membrane localization and its application for clarifying the nonclassical signaling pathway of androgens.

Flux Enhancement in Membrane Distillation Using Nanofiber Membranes

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T. Jiříček

2016-01-01

Full Text Available Membrane distillation (MD is an emerging separation technology, whose largest application potential lies in the desalination of highly concentrated solutions, which are out of the scope of reverse osmosis. Despite many attractive features, this technology is still awaiting large industrial application. The main reason is the lack of commercially available membranes with fluxes comparable to reverse osmosis. MD is a thermal separation process driven by a partial vapour pressure difference. Flux, distillate purity, and thermal efficiency are always in conflict, all three being strictly connected with pore size, membrane hydrophobicity, and thickness. The world has not seen the ideal membrane yet, but nanofibers may offer a solution to these contradictory requirements. Membranes of electrospun PVDF were tested under various conditions on a direct contact (DCMD unit, in order to determine the optimum conditions for maximum flux. In addition, their performance was compared to commonly available PTFE, PE, and PES membranes. It was confirmed that thinner membranes have higher fluxes and a lower distillate purity and also higher energy losses via conduction across the membrane. As both mass and heat transfer are connected, it is best to develop new membranes with a target application in mind, for the specific membrane module and operational conditions.

Spontaneous formation of structurally diverse membrane channel architectures from a single antimicrobial peptide

Science.gov (United States)

Wang, Yukun; Chen, Charles H.; Hu, Dan; Ulmschneider, Martin B.; Ulmschneider, Jakob P.

2016-11-01

Many antimicrobial peptides (AMPs) selectively target and form pores in microbial membranes. However, the mechanisms of membrane targeting, pore formation and function remain elusive. Here we report an experimentally guided unbiased simulation methodology that yields the mechanism of spontaneous pore assembly for the AMP maculatin at atomic resolution. Rather than a single pore, maculatin forms an ensemble of structurally diverse temporarily functional low-oligomeric pores, which mimic integral membrane protein channels in structure. These pores continuously form and dissociate in the membrane. Membrane permeabilization is dominated by hexa-, hepta- and octamers, which conduct water, ions and small dyes. Pores form by consecutive addition of individual helices to a transmembrane helix or helix bundle, in contrast to current poration models. The diversity of the pore architectures--formed by a single sequence--may be a key feature in preventing bacterial resistance and could explain why sequence-function relationships in AMPs remain elusive.

siRNA-based Analysis of the Abrogation of the Protective Function of Membrane-associated Catalase of Tumor Cells.

Science.gov (United States)

Bauer, Georg

2017-02-01

Tumor cells, in contrast to non-malignant cells, show sustained expression of membrane-associated NADPH oxidase-1 and therefore generate extracellular superoxide anions and their dismutation product H 2 O 2 In order to prevent intercellular reactive oxygen species/reactive nitrogen species (ROS/RNS)-dependent apoptosis-inducing signaling, tumor cells need to express membrane-associated catalase that interferes with HOCl and nitric oxide/peroxynitrite signaling. Catalase is attached to tumor cells through the activity of transglutaminase-2 and is prevented from superoxide anion-dependent inhibition through coexpression of membrane-associated superoxide dismutase. Therefore, specific inhibition of membrane-associated catalase should reactivate intercellular ROS/RNS-dependent apoptosis-inducing signaling. These processes are analyzed here through small interfering RNA-mediated knockdown of essential signaling compounds. This allows to establish a rather comprehensive picture of intercellular ROS/RNS signaling that may be instrumental for future therapeutic approaches. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Fabrication of electrospun nanofibrous membranes for membrane distillation application

KAUST Repository

Francis, Lijo

2013-02-01

Nanofibrous membranes of Matrimid have been successfully fabricated using an electrospinning technique under optimized conditions. Nanofibrous membranes are found to be highly hydrophobic with a high water contact angle of 130°. Field emission scanning electron microscopy and pore size distribution analysis revealed the big pore size structure of electrospun membranes to be greater than 2 μm and the pore size distribution is found to be narrow. Flat sheet Matrimid membranes were fabricated via casting followed by phase inversion. The morphology, pore size distribution, and water contact angle were measured and compared with the electrospun membranes. Both membranes fabricated by electrospinning and phase inversion techniques were tested in a direct contact membrane distillation process. Electrospun membranes showed high water vapor flux of 56 kg/m2-h, which is very high compared to the casted membrane as well as most of the fabricated and commercially available highly hydrophobic membranes. ©2013 Desalination Publications.

Structuring detergents for extracting and stabilizing functional membrane proteins.

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Rima Matar-Merheb

Full Text Available BACKGROUND: Membrane proteins are privileged pharmaceutical targets for which the development of structure-based drug design is challenging. One underlying reason is the fact that detergents do not stabilize membrane domains as efficiently as natural lipids in membranes, often leading to a partial to complete loss of activity/stability during protein extraction and purification and preventing crystallization in an active conformation. METHODOLOGY/PRINCIPAL FINDINGS: Anionic calix[4]arene based detergents (C4Cn, n=1-12 were designed to structure the membrane domains through hydrophobic interactions and a network of salt bridges with the basic residues found at the cytosol-membrane interface of membrane proteins. These compounds behave as surfactants, forming micelles of 5-24 nm, with the critical micellar concentration (CMC being as expected sensitive to pH ranging from 0.05 to 1.5 mM. Both by 1H NMR titration and Surface Tension titration experiments, the interaction of these molecules with the basic amino acids was confirmed. They extract membrane proteins from different origins behaving as mild detergents, leading to partial extraction in some cases. They also retain protein functionality, as shown for BmrA (Bacillus multidrug resistance ATP protein, a membrane multidrug-transporting ATPase, which is particularly sensitive to detergent extraction. These new detergents allow BmrA to bind daunorubicin with a Kd of 12 µM, a value similar to that observed after purification using dodecyl maltoside (DDM. They preserve the ATPase activity of BmrA (which resets the protein to its initial state after drug efflux much more efficiently than SDS (sodium dodecyl sulphate, FC12 (Foscholine 12 or DDM. They also maintain in a functional state the C4Cn-extracted protein upon detergent exchange with FC12. Finally, they promote 3D-crystallization of the membrane protein. CONCLUSION/SIGNIFICANCE: These compounds seem promising to extract in a functional state

Alternative energy efficient membrane bioreactor using reciprocating submerged membrane.

Science.gov (United States)

Ho, J; Smith, S; Roh, H K

2014-01-01

A novel membrane bioreactor (MBR) pilot system, using membrane reciprocation instead of air scouring, was operated at constant high flux and daily fluctuating flux to demonstrate its application under peak and diurnal flow conditions. Low and stable transmembrane pressure was achieved at 40 l/m(2)/h (LMH) by use of repetitive membrane reciprocation. The results reveal that the inertial forces acting on the membrane fibers effectively propel foulants from the membrane surface. Reciprocation of the hollow fiber membrane is beneficial for the constant removal of solids that may build up on the membrane surface and inside the membrane bundle. The membrane reciprocation in the reciprocating MBR pilot consumed less energy than coarse air scouring used in conventional MBR systems. Specific energy consumption for the membrane reciprocation was 0.072 kWh/m(3) permeate produced at 40 LMH flux, which is 75% less than for a conventional air scouring system as reported in literature without consideration of energy consumption for biological aeration (0.29 kWh/m(3)). The daily fluctuating flux test confirmed that the membrane reciprocation is effective to handle fluctuating flux up to 50 LMH. The pilot-scale reciprocating MBR system successfully demonstrated that fouling can be controlled via 0.43 Hz membrane reciprocation with 44 mm or higher amplitude.

Avaliação da microinfiltração marginal e profundidade de penetração dos cimentos de ionômero de vidro utilizados como selantes oclusais Evaluation of marginal microleakage and depth of penetration of glass ionomer cements used as occlusal sealants

Directory of Open Access Journals (Sweden)

Marina de Lourdes Calvo Fracasso

2005-09-01

Full Text Available OBJETIVE: the aim of this study was to conduct an in vitro comparison of marginal microleakage (MM and the depth of penetration (DP of glass ionomer cements (GIC and a resin sealant (RS into occlusal pit and fissures. METHODS: for that purpose, 60 intact third molars were equally distributed to 5 groups: G1 - 37% phosphoric acid / Delton; G2 - 40% polyacrylic acid / Ketac-Molar / nail varnish; G3 - Fuji Plus conditioner / Fuji Plus/ nail varnish; G4 -37% phosphoric acid / Vitremer / Finishing gloss; G5 -37% phosphoric acid / Vitremer prepared with a 1:4 ratio of powder / Finishing gloss. The teeth were submitted to a thermal treatment corresponding to 300 cycles (15 sec, 5/55(0C, followed by complete coating with nail varnish, except for 1mm beyond the contour of the sealant. Afterwards, the teeth were immersed in 0.5% basic fuchsine for 24 hours. Thereafter, the teeth were sectioned in buccolingual direction and microscopically analyzed (150x magnification by means of predetermined scores. The results were subject to the Kruskal-Wallis test. RESULTS: there was no statistical difference between the materials tested in relation to the DP, being that all groups displayed nearly complete filling of the fissures. No sealant material was able to prevent dye penetration; however, the GICs provided better results of MM, with significant difference when compared to the RS. CONCLUSION: all materials investigated presented a satisfactory degree of penetration into the fissures; however, the glass ionomer cements displayed better performance in the marginal microleakage test compared to the resin sealant.OBJETIVO: o objetivo deste estudo foi comparar in vitro a microinfiltração marginal (MM e o grau de profundidade de penetração (DP de cimentos de ionômero de vidro (CIV e um selante resinoso (SR em fossas e fissuras oclusais. MATERIAIS E MÉTODOS: para tanto, 60 terceiros molares hígidos foram igualmente distribuídos em 5 grupos: G1- ácido fosf

Energy Efficient Aeration in a Single Low Pressure Hollow Sheet Membrane Filtration Module

DEFF Research Database (Denmark)

Bentzen, Thomas Ruby; Ratkovich, Nicolas Rios; Rasmussen, Michael R.

2011-01-01

The main drawback of membrane bioreactors (MBR) systems is the fouling of the membrane, which is decreased and/or prevented through gas sparging. However, this practice is based on rules of thumb or a trial-and-error approaches which are tedious, very time-consuming, do not necessarily provide...... optimal fouling control and they are not energy efficient. Therefore, dedicated experiments are needed to fully understand the hydrodynamics of it. A hollow sheet (HS) MBR was studied. Experimental velocity measurements were made using micro-propellers and compared to CFD results. A good agreement between...... is homogeneously distributes over the predominant part of the membrane surface....

Membrane order in the plasma membrane and endocytic recycling compartment.

Science.gov (United States)

Iaea, David B; Maxfield, Frederick R

2017-01-01

The cholesterol content of membranes plays an important role in organizing membranes for signal transduction and protein trafficking as well as in modulating the biophysical properties of membranes. While the properties of model or isolated membranes have been extensively studied, there has been little evaluation of internal membranes in living cells. Here, we use a Nile Red based probe, NR12S, and ratiometric live cell imaging, to analyze the membrane order of the plasma membrane and endocytic recycling compartment. We find that after a brief incubation to allow endocytosis, NR12S is distributed between the plasma membrane and the endocytic recycling compartment. The NR12S reports that the endocytic recycling compartment is more highly ordered than the plasma membrane. We also find that the plasma membrane and the endocytic recycling compartment are differentially affected by altering cellular cholesterol levels. The membrane order of the plasma membrane, but not the endocytic recycling compartment, is altered significantly when cellular cholesterol content is increased or decreased by 20%. These results demonstrate that changes in cellular cholesterol differentially alter membrane order within different organelles.

[Prevention of spontaneous preterm birth (excluding preterm premature rupture of membranes): Guidelines for clinical practice - Text of the Guidelines (short text)].

Science.gov (United States)

Sentilhes, L; Sénat, M-V; Ancel, P-Y; Azria, E; Benoist, G; Blanc, J; Brabant, G; Bretelle, F; Brun, S; Doret, M; Ducroux-Schouwey, C; Evrard, A; Kayem, G; Maisonneuve, E; Marcellin, L; Marret, S; Mottet, N; Paysant, S; Riethmuller, D; Rozenberg, P; Schmitz, T; Torchin, H; Langer, B

2016-12-01

To determine the measures to prevent spontaneous preterm birth (excluding preterm premature rupture of membranes)and its consequences. The PubMed database, the Cochrane Library and the recommendations from the French and foreign obstetrical societies or colleges have been consulted. In France, premature birth concerns 60,000 neonates every year (7.4 %), half of them are delivered after spontaneous onset of labor. Among preventable risk factors of spontaneous prematurity, only cessation of smoking is associated to a decrease of prematurity (level of evidence [LE] 1). This is therefore recommended (grade A). Routine screening and treatment of vaginal bacteriosis in general population is not recommended (grade A). Asymptomatic women with single pregnancy without history of preterm delivery and a short cervix between 16 and 24 weeks is the only population in which vaginal progesterone is recommended (grade B). A history-indicated cerclage is not recommended in case of only past history of conisation (grade C), uterine malformation (Professional consensus), isolated history of pretem delivery (grade B) or twin pregnancies in primary (grade B) or secondary (grade C) prevention of preterm birth. A history-indicated cerclage is recommended for single pregnancy with a history of at least 3 late miscarriages or preterm deliveries (grade A).). In case of past history of a single pregnancy delivery before 34 weeks gestation (WG), ultrasound cervical length screening is recommended between 16 and 22 WG in order to propose a cerclage in case of lengthpremature rupture of membranes. Maintenance tocolysis is not recomended (grade B). Antenatal corticosteroid administration is recommended to every woman at risk of preterm delivery before 34 weeks of gestation (grade A). After 34 weeks, evidences are not consistent enough to recommend systematic antenatal corticosteroid treatment (grade B), however, a course might be indicated in the clinical situations associated with the

An Investigation of Low Biofouling Copper-charged Membranes

Science.gov (United States)

Asapu, Sunitha

Water is essential for the survival of life on Earth, but pollutants in water can cause dangerous diseases and fatalities. The need for purified water has been increasing with increasing world population; however, natural sources of water such as rivers, lakes and streams, are progressively falling shorter and shorter of meeting water needs. The provision of clean, drinkable water to people is a key factor for the development of novel and alternative water purification technologies, such as membrane separations. Nanofiltration (NF) is a membrane separations technology that purifies water from lower quality sources, such as brackish water, seawater and wastewater. During the filtration of such sources, materials that are rejected by the membrane may accumulate on the surface of the membrane to foul it. Such materials include organic and inorganic matter, colloids, salts and microorganisms. The former four can often be controlled via pretreatment; however, the accumulation of microorganisms is more problematic to membranes. Biofouling is the accumulation and growth of microorganisms on the surface of membranes and on feed spacers. After attachment, microorganisms excrete extracellular polymeric substances (EPS), which form a matrix around the organism's outer surface as biofilm. These biofilms are detrimental and result in irreversible membrane fouling. Copper and silver ions inactivate the bacterial cells and prevent the DNA replication in microbial cells. Previous studies using copper-charged feed spacers have shown the ability of copper to control biofouling without a significant amount of copper leaching from copper-charged polypropylene (PP) feed spacers during crossflow filtration. Also, filtration using unmodified speed facers experienced almost 70% flux decline, while filtration using copper-charged feed spacers displayed only 25% flux decline. These intriguing results led to the hypothesis that the polymer chemistry could be extrapolated to produce membranes

Polymer nanocomposite membranes with hierarchically structured catalysts for high throughput dehalogenation

Science.gov (United States)

Crock, Christopher A.

Halogenated organics are categorized as primary pollutants by the Environmental Protection Agency. Trichloroethylene (TCE), which had broad industrial use in the past, shows persistence in the environment because of its chemical stability. The large scale use and poor control of TCE resulted in its prolonged release into the environment before the carcinogenic risk associated with TCE was fully understood. TCE pollution stemmed from industrial effluents and improper disposal of solvent waste. Membrane reactors are promising technology for treating TCE polluted groundwater because of the high throughput, relatively low cost of membrane fabrication and facile retrofitting of existing membrane based water treatment facilities with catalytic membrane reactors. Compared to catalytic fluidized or fixed bed reactors, catalytic membrane reactors feature minimal diffusional limitation. Additionally, embedding catalyst within the membrane avoids the need for catalyst recovery and can prevent aggregation of catalytic nanoparticles. In this work, Pd/xGnP, Pd-Au/xGnP, and commercial Pd/Al2O3 nanoparticles were employed in batch and flow-through membrane reactors to catalyze the dehalogenation of TCE in the presence of dissolved H2. Bimetallic Pd-Au/xGnP catalysts were shown to be more active than monometallic Pd/xGnP or commercial Pd/Al 2O3 catalysts. In addition to synthesizing nanocomposite membranes for high-throughput TCE dehalogenation, the membrane based dehalogenation process was designed to minimize the detrimental impact of common catalyst poisons (S2-, HS-, and H2S -) by concurrent oxidation of sulfide species to gypsum in the presence of Ca2+ and removal of gypsum through membrane filtration. The engineered membrane dehalogenation process demonstrated that bimetallic Pd-Au/xGnP catalysts resisted deactivation by residual sulfide species after oxidation, and showed complete removal of gypsum during membrane filtration.

Effects of internal limiting membrane peeling during vitrectomy for macula-off primary rhegmatogenous retinal detachment.

Science.gov (United States)

Blanco-Teijeiro, María José; Bande Rodriguez, Manuel; Mansilla Cuñarro, Raquel; Paniagua Fernández, Laura; Ruiz-Oliva Ruiz, Francisco; Piñeiro Ces, Antonio

2018-03-01

To determine the effectiveness of internal limiting membrane peeling during vitrectomy for macula-off primary rhegmatogenous retinal detachment in the prevention of postoperative epiretinal membrane formation and achievement of good visual outcomes and to identify preoperative and intraoperative risk factors for epiretinal membrane formation. We retrospectively analyzed data from 62 eyes of 62 consecutive patients with macula-off primary rhegmatogenous retinal detachment who underwent vitrectomy with (n = 30) or without (n = 32) internal limiting membrane peeling between January 2014 and March 2016 and were followed up for at least 12 months. The effects of internal limiting membrane peeling on visual outcomes and postoperative recovery of the macular structure were determined. We subsequently divided patients into an epiretinal membrane group and a non-epiretinal membrane group and assessed the effects of various preoperative and intraoperative factors on postoperative epiretinal membrane formation. Postoperative epiretinal membrane developed in 10 patients in the no internal limiting membrane peeling group and three patients in the internal limiting membrane peeling group. Postoperative visual acuity significantly improved in both groups. Epiretinal membrane formation was found to be correlated with a higher number of retinal breaks. Our results suggest that internal limiting membrane peeling during macula-off primary rhegmatogenous retinal detachment surgery can reduce the occurrence of postoperative epiretinal membrane, is safe, and results in favorable visual outcomes.

Desmosome Assembly and Disassembly Are Membrane Raft-Dependent

Science.gov (United States)

Faundez, Victor; Koval, Michael; Mattheyses, Alexa L.; Kowalczyk, Andrew P.

2014-01-01

Strong intercellular adhesion is critical for tissues that experience mechanical stress, such as the skin and heart. Desmosomes provide adhesive strength to tissues by anchoring desmosomal cadherins of neighboring cells to the intermediate filament cytoskeleton. Alterations in assembly and disassembly compromise desmosome function and may contribute to human diseases, such as the autoimmune skin blistering disease pemphigus vulgaris (PV). We previously demonstrated that PV auto-antibodies directed against the desmosomal cadherin desmoglein 3 (Dsg3) cause loss of adhesion by triggering membrane raft-mediated Dsg3 endocytosis. We hypothesized that raft membrane microdomains play a broader role in desmosome homeostasis by regulating the dynamics of desmosome assembly and disassembly. In human keratinocytes, Dsg3 is raft associated as determined by biochemical and super resolution immunofluorescence microscopy methods. Cholesterol depletion, which disrupts rafts, prevented desmosome assembly and adhesion, thus functionally linking rafts to desmosome formation. Interestingly, Dsg3 did not associate with rafts in cells lacking desmosomal proteins. Additionally, PV IgG-induced desmosome disassembly occurred by redistribution of Dsg3 into raft-containing endocytic membrane domains, resulting in cholesterol-dependent loss of adhesion. These findings demonstrate that membrane rafts are required for desmosome assembly and disassembly dynamics, suggesting therapeutic potential for raft targeting agents in desmosomal diseases such as PV. PMID:24498201

Super liquid-repellent gas membranes for carbon dioxide capture and heart-lung machines.

Science.gov (United States)

Paven, Maxime; Papadopoulos, Periklis; Schöttler, Susanne; Deng, Xu; Mailänder, Volker; Vollmer, Doris; Butt, Hans-Jürgen

2013-01-01

In a gas membrane, gas is transferred between a liquid and a gas through a microporous membrane. The main challenge is to achieve a high gas transfer while preventing wetting and clogging. With respect to the oxygenation of blood, haemocompatibility is also required. Here we coat macroporous meshes with a superamphiphobic-or liquid repellent-layer to meet this challenge. The superamphiphobic layer consists of a fractal-like network of fluorinated silicon oxide nanospheres; gas trapped between the nanospheres keeps the liquid from contacting the wall of the membrane. We demonstrate the capabilities of the membrane by capturing carbon dioxide gas into a basic aqueous solution and in addition use it to oxygenate blood. Usually, blood tends to clog membranes because of the abundance of blood cells, platelets, proteins and lipids. We show that human blood stored in a superamphiphobic well for 24 h can be poured off without leaving cells or adsorbed protein behind.

Multicomponent transport in membranes for redox flow batteries

Science.gov (United States)

Monroe, Charles

2015-03-01

Redox flow batteries (RFBs) incorporate separator membranes, which ideally prevent mixing of electrochemically active species while permitting crossover of inactive supporting ions. Understanding crossover and membrane selectivity may require multicomponent transport models that account for solute/solute interactions within the membrane, as well as solute/membrane interactions. Application of the Onsager-Stefan-Maxwell formalism allows one to account for all the dissipative phenomena that may accompany component fluxes through RFB membranes. The magnitudes of dissipative interactions (diffusional drag forces) are quantified by matching experimentally established concentration transients with theory. Such transients can be measured non-invasively using DC conductometry, but the accuracy of this method requires precise characterization of the bulk RFB electrolytes. Aqueous solutions containing both vanadyl sulfate (VOSO4) and sulfuric acid (H2SO4) are relevant to RFB technology. One of the first precise characterizations of aqueous vanadyl sulfate has been implemented and will be reported. To assess the viability of a separator for vanadium RFB applications with cell-level simulations, it is critical to understand the tendencies of various classes of membranes to absorb (uptake) active species, and to know the relative rates of active-species and supporting-electrolyte diffusion. It is also of practical interest to investigate the simultaneous diffusion of active species and supports, because interactions between solutes may ultimately affect the charge efficiency and power efficiency of the RFB system as a whole. A novel implementation of Barnes's classical model of dialysis-cell diffusion [Physics 5:1 (1934) 4-8] is developed to measure the binary diffusion coefficients and sorption equilibria for single solutes (VOSO4 or H2SO4) in porous membranes and cation-exchange membranes. With the binary diffusion and uptake measurement in hand, a computer simulation that

Giant plasma membrane vesicles: models for understanding membrane organization.

Science.gov (United States)

Levental, Kandice R; Levental, Ilya

2015-01-01

The organization of eukaryotic membranes into functional domains continues to fascinate and puzzle cell biologists and biophysicists. The lipid raft hypothesis proposes that collective lipid interactions compartmentalize the membrane into coexisting liquid domains that are central to membrane physiology. This hypothesis has proven controversial because such structures cannot be directly visualized in live cells by light microscopy. The recent observations of liquid-liquid phase separation in biological membranes are an important validation of the raft hypothesis and enable application of the experimental toolbox of membrane physics to a biologically complex phase-separated membrane. This review addresses the role of giant plasma membrane vesicles (GPMVs) in refining the raft hypothesis and expands on the application of GPMVs as an experimental model to answer some of key outstanding problems in membrane biology. Copyright © 2015 Elsevier Inc. All rights reserved.

Analysis of cerium-composite polymer-electrolyte membranes during and after accelerated oxidative-stability test

Science.gov (United States)

Shin, Dongwon; Han, Myungseong; Shul, Yong-Gun; Lee, Hyejin; Bae, Byungchan

2018-02-01

The oxidative stability of membranes constructed from a composite of pristine sulfonated poly(arylene ether sulfone) and cerium was investigated by conducting an accelerated oxidative-stability test at the open-circuit voltage (OCV). The membranes were analyzed in situ through OCV and impedance measurements, cyclic voltammetry, and linear-sweep voltammetry to monitor the electrochemical properties during the stability test. Although the high-frequency resistance of a composite membrane was slightly higher than that of a pristine membrane because of the exchange of protons from the sulfonic acid with cerium ions, the composite membrane maintained its potential for much longer than the pristine membrane. The effect of the cerium ions as radical scavengers was confirmed by analyzing the drain water and chemical structure after operation. These post-operation analyses confirmed that cerium ions improved the oxidative stability of the hydrocarbon-based polymer during fuel-cell operation. It is clear that the cerium-based radical scavengers prevented chemical degradation of the polymer membrane as well as the electrode in terms of hydrogen cross-over, polymer-chain scission, and the electrochemical surface area, while they rarely diffused outward from the membrane.

Prevalence of Dental Caries and Periodontal Disease in Mexican American Children Aged 5 to 17 Years: Results from Southwestern HHANES, 1982-83.

Science.gov (United States)

Ismail, Amid L.; And Others

1987-01-01

Dental caries and periodontal disease in Mexican American children of the southwestern United States occur mainly in molars, lending strong support for the use of fissure sealants as a preventive procedure. This study also reports on the prevalence of fillings decay and gingivitis in this population. (VM)

Feracrylum does not Reduce the Incidence of Seroma Formation ...

African Journals Online (AJOL)

different unsuccessful procedures have been tried to prevent seroma. ... mastectomy. Among them are; shoulder immobilization, use of fibrin sealant, various drain regimens and dead space obliteration with no success. Feracrylum, a coagulant, is an incomplete iron salt of ... established in previous studies that with use of.

Free volume of mixed cation borosilicate glass sealants elucidated by positron annihilation lifetime spectroscopy and its correlation with glass properties

Science.gov (United States)

Ojha, Prasanta K.; Rath, Sangram K.; Sharma, Sandeep K.; Sudarshan, Kathi; Pujari, Pradeep K.; Chongdar, Tapas K.; Gokhale, Nitin M.

2015-01-01

The role of La+3/Sr+2 ratios, which is varied from 0.08 to 5.09, on density, molar volume, packing fraction, free volume, thermal and electrical properties in strontium lanthanum aluminoborosilicate based glass sealants intended for solid oxide fuel cell (SOFC) applications is evaluated. The studies reveal expansion of the glass network evident from increasing molar volume and decreasing packing fraction of glasses with progressive La+3 substitutions. The molecular origin of these macroscopic structural features can be accounted for by the free volume parameters measured from positron annihilation lifetime spectroscopy (PALS). The La+3 induced expanded glass networks show increased number of subnanoscopic voids with larger sizes, as revealed from the ortho-positronium (o-Ps) lifetime and its intensity. A remarkably direct correspondence between the molar volume and fractional free volume trend is established with progressive La2O3 substitution in the glasses. The effect of these structural changes on the glass transition temperature, softening temperature, coefficient of thermal expansion, thermal stability as well as electrical conductivity has been studied.

Structure and physical properties of bio membranes and model membranes

International Nuclear Information System (INIS)

Tibor Hianik

2006-01-01

Bio membranes belong to the most important structures of the cell and the cell organelles. They play not only structural role of the barrier separating the external and internal part of the membrane but contain also various functional molecules, like receptors, ionic channels, carriers and enzymes. The cell membrane also preserves non-equilibrium state in a cell which is crucial for maintaining its excitability and other signaling functions. The growing interest to the bio membranes is also due to their unique physical properties. From physical point of view the bio membranes, that are composed of lipid bilayer into which are incorporated integral proteins and on their surface are anchored peripheral proteins and polysaccharides, represent liquid s crystal of smectic type. The bio membranes are characterized by anisotropy of structural and physical properties. The complex structure of bio membranes makes the study of their physical properties rather difficult. Therefore several model systems that mimic the structure of bio membranes were developed. Among them the lipid monolayers at an air-water interphase, bilayer lipid membranes, supported bilayer lipid membranes and liposomes are most known. This work is focused on the introduction into the physical word of the bio membranes and their models. After introduction to the membrane structure and the history of its establishment, the physical properties of the bio membranes and their models are stepwise presented. The most focus is on the properties of lipid monolayers, bilayer lipid membranes, supported bilayer lipid membranes and liposomes that were most detailed studied. This lecture has tutorial character that may be useful for undergraduate and graduate students in the area of biophysics, biochemistry, molecular biology and bioengineering, however it contains also original work of the author and his co-worker and PhD students, that may be useful also for specialists working in the field of bio membranes and model

Voltage-Gated Transport of Nanoparticles across Free-Standing All-Carbon-Nanotube-Based Hollow-Fiber Membranes.

Science.gov (United States)

Wei, Gaoliang; Quan, Xie; Chen, Shuo; Fan, Xinfei; Yu, Hongtao; Zhao, Huimin

2015-07-15

Understanding the mechanism underlying controllable transmembrane transport observed in biological membranes benefits the development of next-generation separation membranes for a variety of important applications. In this work, on the basis of common structural features of cell membranes, a very simple biomimetic membrane system exhibiting gated transmembrane performance has been constructed using all-carbon-nanotube (CNT)-based hollow-fiber membranes. The conductive CNT membranes with hydrophobic pore channels can be positively or negatively charged and are consequently capable of regulating the transport of nanoparticles across their pore channels by their "opening" or "closing". The switch between penetration and rejection of nanoparticles through/by CNT membranes is of high efficiency and especially allows dynamic control. The underlying mechanism is that CNT pore channels with different polarities can prompt or prevent the formation of their noncovalent interactions with charged nanoparticles, resulting in their rejection or penetration by/through the CNT membranes. The theory about noncovalent interactions and charged pore channels may provide new insight into understanding the complicated ionically and bimolecularly gated transport across cell membranes and can contribute to many other important applications beyond the water purification and resource recovery demonstrated in this study.

A New Strain Collection for Improved Expression of Outer Membrane Proteins

Directory of Open Access Journals (Sweden)

Ina Meuskens

2017-11-01

Full Text Available Almost all integral membrane proteins found in the outer membranes of Gram-negative bacteria belong to the transmembrane β-barrel family. These proteins are not only important for nutrient uptake and homeostasis, but are also involved in such processes as adhesion, protein secretion, biofilm formation, and virulence. As surface exposed molecules, outer membrane β-barrel proteins are also potential drug and vaccine targets. High production levels of heterologously expressed proteins are desirable for biochemical and especially structural studies, but over-expression and subsequent purification of membrane proteins, including outer membrane proteins, can be challenging. Here, we present a set of deletion mutants derived from E. coli BL21(DE3 designed for the over-expression of recombinant outer membrane proteins. These strains harbor deletions of four genes encoding abundant β-barrel proteins in the outer membrane (OmpA, OmpC, OmpF, and LamB, both single and in all combinations of double, triple, and quadruple knock-outs. The sequences encoding these outer membrane proteins were deleted completely, leaving only a minimal scar sequence, thus preventing the possibility of genetic reversion. Expression tests in the quadruple mutant strain with four test proteins, including a small outer membrane β-barrel protein and variants thereof as well as two virulence-related autotransporters, showed significantly improved expression and better quality of the produced proteins over the parent strain. Differences in growth behavior and aggregation in the presence of high salt were observed, but these phenomena did not negatively influence the expression in the quadruple mutant strain when handled as we recommend. The strains produced in this study can be used for outer membrane protein production and purification, but are also uniquely useful for labeling experiments for biophysical measurements in the native membrane environment.

Polyurethane Nanofiber Membranes for Waste Water Treatment by Membrane Distillation

Directory of Open Access Journals (Sweden)

T. Jiříček

2017-01-01

Full Text Available Self-sustained electrospun polyurethane nanofiber membranes were manufactured and tested on a direct-contact membrane distillation unit in an effort to find the optimum membrane thickness to maximize flux rate and minimize heat losses across the membrane. Also salt retention and flux at high salinities up to 100 g kg−1 were evaluated. Even though the complex structure of nanofiber layers has extreme specific surface and porosity, membrane performance was surprisingly predictable; the highest flux was achieved with the thinnest membranes and the best energy efficiency was achieved with the thickest membranes. All membranes had salt retention above 99%. Nanotechnology offers the potential to find modern solutions for desalination of waste waters, by introducing new materials with revolutionary properties, but new membranes must be developed according to the target application.

Fouling in Membrane Distillation, Osmotic Distillation and Osmotic Membrane Distillation

Directory of Open Access Journals (Sweden)

Mourad Laqbaqbi

2017-03-01

Full Text Available Various membrane separation processes are being used for seawater desalination and treatment of wastewaters in order to deal with the worldwide water shortage problem. Different types of membranes of distinct morphologies, structures and physico-chemical characteristics are employed. Among the considered membrane technologies, membrane distillation (MD, osmotic distillation (OD and osmotic membrane distillation (OMD use porous and hydrophobic membranes for production of distilled water and/or concentration of wastewaters for recovery and recycling of valuable compounds. However, the efficiency of these technologies is hampered by fouling phenomena. This refers to the accumulation of organic/inorganic deposits including biological matter on the membrane surface and/or in the membrane pores. Fouling in MD, OD and OMD differs from that observed in electric and pressure-driven membrane processes such electrodialysis (ED, membrane capacitive deionization (MCD, reverse osmosis (RO, nanofiltration (NF, ultrafiltration (UF, microfiltration (MF, etc. Other than pore blockage, fouling in MD, OD and OMD increases the risk of membrane pores wetting and reduces therefore the quantity and quality of the produced water or the concentration efficiency of the process. This review deals with the observed fouling phenomena in MD, OD and OMD. It highlights different detected fouling types (organic fouling, inorganic fouling and biofouling, fouling characterization techniques as well as various methods of fouling reduction including pretreatment, membrane modification, membrane cleaning and antiscalants application.

Effect of internal limiting membrane peeling on the development of epiretinal membrane after pars plana vitrectomy for primary rhegmatogenous retinal detachment.

Science.gov (United States)

Nam, Ki Yup; Kim, Jung Yeul

2015-05-01

To investigate the difference in the occurrence of postoperative epiretinal membranes (ERMs) in vitrectomy for rhegmatogenous retinal detachment with and without peeling of the internal limiting membrane (ILM). The medical records of the 135 patients, who underwent vitrectomy for primary rhegmatogenous retinal detachment from November 2007 to August 2011, were analyzed retrospectively. Of the subjects, 70 patients underwent ILM peeling during the surgery and 65 did not. The best-corrected visual acuity, fundus photograph, and optical coherence tomography were collected 3, 6, and 12 months postoperatively. The relationship between ILM peeling and the preoperative findings of rhegmatogenous retinal detachment and development of a postoperative ERM was analyzed. No ERM occurred in the ILM peeling group, whereas an ERM occurred in 14 of 65 patients who underwent vitrectomy without ILM peeling (21.5%). This difference was significant (P peeling group and was significantly higher 12 months postoperatively (P = 0.03). Internal limiting membrane peeling seems to prevent the occurrence of a postoperative ERM in patients with primary rhegmatogenous retinal detachment.

Flow and fouling in membrane filters: Effects of membrane morphology

Science.gov (United States)

Sanaei, Pejman; Cummings, Linda J.

2015-11-01

Membrane filters are widely-used in microfiltration applications. Many types of filter membranes are produced commercially, for different filtration applications, but broadly speaking the requirements are to achieve fine control of separation, with low power consumption. The answer to this problem might seem obvious: select the membrane with the largest pore size and void fraction consistent with the separation requirements. However, membrane fouling (an inevitable consequence of successful filtration) is a complicated process, which depends on many parameters other than membrane pore size and void fraction; and which itself greatly affects the filtration process and membrane functionality. In this work we formulate mathematical models that can (i) account for the membrane internal morphology (internal structure, pore size & shape, etc.); (ii) fouling of membranes with specific morphology; and (iii) make some predictions as to what type of membrane morphology might offer optimum filtration performance.

[Use of fibrin glue in the prevention of leakage in pancreatico-jejunal anastomoses].

Science.gov (United States)

Stojanović, M; Jeremic, M; Stojanović, P; Stojiljković, M; Gmijović, D; Stanojković, Z; Savić, V; Djordjević, V; Cvetković, Z; Kostov, M; Colović, R

2002-01-01

The aim of this study was to test the protective effects of fibrin sealing on the pancreatico-jejunostomy (PJA), the high-risk anastomosis following pancreas head resection. Experimental study was performed on the mongrel dogs, divided in two groups (20 animals each): Experimental group-with end to end "dunking" PJA, protected by temporary occlusion of the pancreatic duct with fibrin sealant/Tissucol/Immuno Ag/, while control group was without any protective procedure. The animals were followed 5 months in order to study: protective effects of such procedure on the PJA quantified with the percent of anastomotic leakage, effects of the exocrine secretion and effects the endocrine function Results: PJA leakage occurred in 13.33% in control group. No leakage was registered in experimental group. Biochemical, histological and electron microscopic study showed slight transitory elevation of amylase levels. Fibrin glue plug was dissolved and pancreatic juice output was reestablished 12th days postoperatively. Long term follow-up showed no damages of the endocrine and exocrine pancreas. Pancreatic duct occlusion with fibrin glue appeared to be an useful method in the prevention of pancreatico-jejunostomy leakage, without negative effects on the exocrine and endocrine pancreas.

Specific binding of prostaglandin E2 to membrane preparations from human skin: receptor modulation by UVB-irradiation and chemical agents

International Nuclear Information System (INIS)

Lord, J.T.; Ziboh, V.A.

1979-01-01

Human skin membranes bind prostaglandin E2 (PGE2) with high affinity and specificity. This binding is inhibited by trypsin or heat treatment suggesting that PGE2 receptors have protein components. Exposure of the membranes to ultraviolet irradiation (UVB) resulted in the loss of the membrane binding capacity for PGE2. This UVB-inhibitory effect could be prevented by a known protein sulfhydryl-oxidizing agent and a known lipid anti-oxidant

In Vitro and In Vivo Study of a Novel Porcine Collagen Membrane for Guided Bone Regeneration

Directory of Open Access Journals (Sweden)

Eisner Salamanca

2016-11-01

Full Text Available For years, in order to improve bone regeneration and prevent the need of a second stage surgery to remove non-resorbable membranes, biological absorbable membranes have gradually been developed and applied in guided tissue regeneration (GTR. The present study’s main objective was to achieve space maintenance and bone regeneration using a new freeze-dried developed porcine collagen membrane, and compare it with an already commercial collagen membrane, when both were used with a bovine xenograft in prepared alveolar ridge bone defects. Prior to surgery, the membrane’s vitality analysis showed statistically significant higher cell proliferation in the test membrane over the commercial one. In six beagle dogs, commercial bone xenograft was packed in lateral ridge bone defects prepared in the left and right side and then covered with test porcine collagen membrane or commercial collagen membrane. Alveolar height changes were measured. Histomorphometric results, in vitro and in vivo properties indicated that the new porcine collagen membrane is biocompatible, enhances bone xenograft osteoconduction, and reduces the alveolar ridge height reabsorption rate.

Fundamentals of membrane bioreactors materials, systems and membrane fouling

CERN Document Server

Ladewig, Bradley

2017-01-01

This book provides a critical, carefully researched, up-to-date summary of membranes for membrane bioreactors. It presents a comprehensive and self-contained outline of the fundamentals of membrane bioreactors, especially their relevance as an advanced water treatment technology. This outline helps to bring the technology to the readers’ attention, and positions the critical topic of membrane fouling as one of the key impediments to its more widescale adoption. The target readership includes researchers and industrial practitioners with an interest in membrane bioreactors.

Advances in biotreatment of acid mine drainage and biorecovery of metals: 2. Membrane bioreactor system for sulfate reduction.

Science.gov (United States)

Tabak, Henry H; Govind, Rakesh

2003-12-01

Several biotreatmemt techniques for sulfate conversion by the sulfate reducing bacteria (SRB) have been proposed in the past, however few of them have been practically applied to treat sulfate containing acid mine drainage (AMD). This research deals with development of an innovative polypropylene hollow fiber membrane bioreactor system for the treatment of acid mine water from the Berkeley Pit, Butte, MT, using hydrogen consuming SRB biofilms. The advantages of using the membrane bioreactor over the conventional tall liquid phase sparged gas bioreactor systems are: large microporous membrane surface to the liquid phase; formation of hydrogen sulfide outside the membrane, preventing the mixing with the pressurized hydrogen gas inside the membrane; no requirement of gas recycle compressor; membrane surface is suitable for immobilization of active SRB, resulting in the formation of biofilms, thus preventing washout problems associated with suspended culture reactors; and lower operating costs in membrane bioreactors, eliminating gas recompression and gas recycle costs. Information is provided on sulfate reduction rate studies and on biokinetic tests with suspended SRB in anaerobic digester sludge and sediment master culture reactors and with SRB biofilms in bench-scale SRB membrane bioreactors. Biokinetic parameters have been determined using biokinetic models for the master culture and membrane bioreactor systems. Data are presented on the effect of acid mine water sulfate loading at 25, 50, 75 and 100 ml/min in scale-up SRB membrane units, under varied temperatures (25, 35 and 40 degrees C) to determine and optimize sulfate conversions for an effective AMD biotreatment. Pilot-scale studies have generated data on the effect of flow rates of acid mine water (MGD) and varied inlet sulfate concentrations in the influents on the resultant outlet sulfate concentration in the effluents and on the number of SRB membrane modules needed for the desired sulfate conversion in

Adaptive silicone-membrane lenses: planar vs. shaped membrane

CSIR Research Space (South Africa)

Schneider, F

2009-08-01

Full Text Available Engineering, Georges-Koehler-Allee 102, Freiburg 79110, Germany florian.schneider@imtek.uni-freiburg.de ABSTRACT We compare the performance and optical quality of two types of adaptive fluidic silicone-membrane lenses. The membranes feature either a...-membrane lenses: planar vs. shaped membrane Florian Schneider1,2, Philipp Waibel2 and Ulrike Wallrabe2 1 CSIR, Materials Science and Manufacturing, PO Box 395, Pretoria 0001, South Africa 2 University of Freiburg – IMTEK, Department of Microsystems...

Membrane omega-3 Fatty Acid deficiency as a preventable risk factor for comorbid coronary heart disease in major depressive disorder.

Science.gov (United States)

McNamara, Robert K

2009-01-01

Major depression disorder (MDD) significantly increases the risk for coronary heart disease (CHD) which is a leading cause of mortality in patients with MDD. Moreover, depression is frequently observed in a subset of patients following acute coronary syndrome (ACS) and increases risk for mortality. Here evidence implicating omega-3 (n-3) fatty acid deficiency in the pathoaetiology of CHD and MDD is reviewed, and the hypothesis that n-3 fatty acid deficiency is a preventable risk factor for CHD comorbidity in MDD patients is evaluated. This hypothesis is supported by cross-national and cross-sectional epidemiological surveys finding an inverse correlation between n-3 fatty acid status and prevalence rates of both CHD and MDD, prospective studies finding that lower dietary or membrane EPA+DHA levels increase risk for both MDD and CHD, case-control studies finding that the n-3 fatty acid status of MDD patients places them at high risk for emergent CHD morbidity and mortality, meta-analyses of controlled n-3 fatty acid intervention studies finding significant advantage over placebo for reducing depression symptom severity in MDD patients, and for secondary prevention of cardiac events in CHD patients, findings that n-3 fatty acid status is inversely correlated with other documented CHD risk factors, and patients diagnosed with MDD after ACS exhibit significantly lower n-3 fatty acid status compared with nondepressed ACS patients. This body of evidence provides strong support for future studies to evaluate the effects of increasing dietary n-3 fatty acid status on CHD comorbidity and mortality in MDD patients.

Degradation of Polypropylene Membranes Applied in Membrane Distillation Crystallizer