LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 13

Search options

  1. Article ; Online: Me Without My Smartphone? Never! Predictors of Willingness for Smartphone Separation and Nomophobia

    Muench, Ricardo / Muench, Catharina

    HCI International 2020 - Posters

    Abstract: The smartphone as a ubiquitous mobile computer can be regarded as a ‘digital companion’, being with us 24/7 and supporting us in every aspect of modern life. This companionship might lead to a psychological attachment to the device comparable to the ... ...

    Abstract The smartphone as a ubiquitous mobile computer can be regarded as a ‘digital companion’, being with us 24/7 and supporting us in every aspect of modern life. This companionship might lead to a psychological attachment to the device comparable to the attachment to social (human) partners, and ultimately even compulsive usage. Here, a relevant construct is the fear of missing out (short: FoMO) leading to a constant checking of one’s phone. Furthermore, users can develop a fear called ‘nomophobia’ (no-mobile-phone phobia). Despite this fear, resolutions to reduce overuse also known as a ‘digital detox’ is an emerging trend. Our research aims at revealing predictors of nomophobia and the willingness to limit one’s smartphone usage, and which sub-factors of nomophobia are dominating. N = 220 participants filled out an online survey including factors like compulsive usage, FoMO, nomophobia, frequency of smartphone usage and willingness to separate from one’s smartphone. Multiple regression analyses revealed potential predictors for nomophobia and willingness for smartphone separation.
    Keywords covid19
    Publisher PMC
    Document type Article ; Online
    DOI 10.1007/978-3-030-50732-9_29
    Database COVID19

    Kategorien

  2. Article ; Online: 16p11.2 microdeletion imparts transcriptional alterations in human iPSC-derived models of early neural development.

    Roth, Julien G / Muench, Kristin L / Asokan, Aditya / Mallett, Victoria M / Gai, Hui / Verma, Yogendra / Weber, Stephen / Charlton, Carol / Fowler, Jonas L / Loh, Kyle M / Dolmetsch, Ricardo E / Palmer, Theo D

    eLife

    2020  Volume 9

    Abstract: Microdeletions and microduplications of the 16p11.2 chromosomal locus are associated with syndromic neurodevelopmental disorders and reciprocal physiological conditions such as macro/microcephaly and high/low body mass index. To facilitate cellular and ... ...

    Abstract Microdeletions and microduplications of the 16p11.2 chromosomal locus are associated with syndromic neurodevelopmental disorders and reciprocal physiological conditions such as macro/microcephaly and high/low body mass index. To facilitate cellular and molecular investigations into these phenotypes, 65 clones of human induced pluripotent stem cells (hiPSCs) were generated from 13 individuals with 16p11.2 copy number variations (CNVs). To ensure these cell lines were suitable for downstream mechanistic investigations, a customizable bioinformatic strategy for the detection of random integration and expression of reprogramming vectors was developed and leveraged towards identifying a subset of 'footprint'-free hiPSC clones. Transcriptomic profiling of cortical neural progenitor cells derived from these hiPSCs identified alterations in gene expression patterns which precede morphological abnormalities reported at later neurodevelopmental stages. Interpreting clinical information-available with the cell lines by request from the Simons Foundation Autism Research Initiative-with this transcriptional data revealed disruptions in gene programs related to both nervous system function and cellular metabolism. As demonstrated by these analyses, this publicly available resource has the potential to serve as a powerful medium for probing the etiology of developmental disorders associated with 16p11.2 CNVs.
    MeSH term(s) Autism Spectrum Disorder/genetics ; Autistic Disorder ; Chromosome Deletion ; Chromosome Disorders ; Chromosomes, Human, Pair 16 ; DNA Copy Number Variations ; Gene Deletion ; Gene Expression Regulation, Developmental/drug effects ; Gene Expression Regulation, Developmental/genetics ; Humans ; Induced Pluripotent Stem Cells/physiology ; Intellectual Disability ; Neurodevelopmental Disorders ; Neurons/physiology ; Transcobalamins
    Chemical Substances Transcobalamins
    Language English
    Publishing date 2020-11-10
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2687154-3
    ISSN 2050-084X ; 2050-084X
    ISSN (online) 2050-084X
    ISSN 2050-084X
    DOI 10.7554/eLife.58178
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article: Genetic analysis of the ZNF804A gene in Mexican patients with schizophrenia, schizoaffective disorder and bipolar disorder

    Münch-Anguiano, Lucía / Camarena, Beatriz / Nieto-Quinto, Jesica / de la Torre, Patricia / Pedro Laclette, Juan / Hirata-Hernández, Harumi / Hernández-Muñoz, Sandra / Aguilar-García, Alejandro / Becerra-Palars, Claudia / Gutiérrez-Mora, Doris / Ortega-Ortiz, Hiram / Escamilla-Orozco, Raúl / Saracco-Álvarez, Ricardo / Bustos-Jaimes, Ismael

    Gene. 2022 June 30, v. 829

    2022  

    Abstract: Evidence suggests that schizophrenia (SCZ), schizoaffective disorder (SAD) and bipolar disorder (BPD) share genetic risk variants. ZNF804A gene has been associated with these disorders in different populations. GWAS and candidate gene studies have ... ...

    Abstract Evidence suggests that schizophrenia (SCZ), schizoaffective disorder (SAD) and bipolar disorder (BPD) share genetic risk variants. ZNF804A gene has been associated with these disorders in different populations. GWAS and candidate gene studies have reported association between the rs1344706 A allele with SCZ, SAD and BPD in European and Asian populations. In Mexican patients, no studies have specifically analyzed ZNF804A gene variants with these disorders. The aim of the study was to analyze the rs1344706 and identify common and rare variants in a targeted region of the ZNF804A gene in Mexican patients with SCZ, BPD and SAD compared with a control group. We genotyped the rs1344706 in 228 Mexican patients diagnosed with SCZ, SAD and BPD, and 295 controls. Also, an additional sample of 167 patients with these disorders and 170 controls was analyzed to identify rare and common variants using the Sanger-sequence analysis of a targeted region of ZNF804A gene. Association analysis of rs1344706 observed a higher frequency of A allele in the patients compared with the control group; however, did not show statistical differences after Bonferronís correction (χ2 = 5.3, p = 0.0208). In the sequence analysis, we did not identify rare variants; however, we identified three common variants: rs3046266, rs1366842 and rs12477430. A comparison of the three identified variants between patients and controls did not show statistical differences (p > 0.0125). Finally, haplotype analysis did not show statistical differences between SCZ, SAD and BPD and controls. Our findings did not support the evidence suggesting that ZNF804A gene participates in the etiology of SCZ, SAD and BPD. Future studies are needed in a larger sample size to identify the effect of this gene in psychiatric disorders.
    Keywords alleles ; bipolar disorder ; etiology ; genetic analysis ; haplotypes ; risk ; sample size ; schizophrenia ; sequence analysis
    Language English
    Dates of publication 2022-0630
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 391792-7
    ISSN 1879-0038 ; 0378-1119
    ISSN (online) 1879-0038
    ISSN 0378-1119
    DOI 10.1016/j.gene.2022.146508
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  4. Article ; Online: Targeted Long-Read Sequencing Reveals Comprehensive Architecture, Burden, and Transcriptional Signatures from Hepatitis B Virus-Associated Integrations and Translocations in Hepatocellular Carcinoma Cell Lines.

    Ramirez, Ricardo / van Buuren, Nicholas / Gamelin, Lindsay / Soulette, Cameron / May, Lindsey / Han, Dong / Yu, Mei / Choy, Regina / Cheng, Guofeng / Bhardwaj, Neeru / Chiu, Joy / Muench, Robert C / Delaney, William E / Mo, Hongmei / Feierbach, Becket / Li, Li

    Journal of virology

    2021  Volume 95, Issue 19, Page(s) e0029921

    Abstract: Hepatitis B virus (HBV) can integrate into the chromosomes of infected hepatocytes, creating potentially oncogenic lesions that can lead to hepatocellular carcinoma (HCC). However, our current understanding of integrated HBV DNA architecture, burden, and ...

    Abstract Hepatitis B virus (HBV) can integrate into the chromosomes of infected hepatocytes, creating potentially oncogenic lesions that can lead to hepatocellular carcinoma (HCC). However, our current understanding of integrated HBV DNA architecture, burden, and transcriptional activity is incomplete due to technical limitations. A combination of genomics approaches was used to describe HBV integrations and corresponding transcriptional signatures in three HCC cell lines: huH-1, PLC/PRF/5, and Hep3B. To generate high-coverage, long-read sequencing data, a custom panel of HBV-targeting biotinylated oligonucleotide probes was designed. Targeted long-read DNA sequencing captured entire HBV integration events within individual reads, revealing that integrations may include deletions and inversions of viral sequences. Surprisingly, all three HCC cell lines contain integrations that are associated with host chromosomal translocations. In addition, targeted long-read RNA sequencing allowed for the assignment of transcriptional activity to specific integrations and resolved the contribution of overlapping HBV transcripts. HBV transcripts chimeric with host sequences were resolved in their entirety and often included >1,000 bp of host sequence. This study provides the first comprehensive description of HBV integrations and associated transcriptional activity in three commonly utilized HCC-derived cell lines. The application of novel methods sheds new light on the complexity of these integrations, including HBV bidirectional transcription, nested transcripts, silent integrations, and host genomic rearrangements. The observation of multiple HBV-associated chromosomal translocations gives rise to the hypothesis that HBV is a driver of genetic instability and provides a potential new mechanism for HCC development.
    MeSH term(s) Carcinoma, Hepatocellular/virology ; Cell Line, Tumor ; DNA, Viral/genetics ; Hepatitis B virus/genetics ; Hepatitis B virus/physiology ; Humans ; Sequence Analysis, DNA ; Sequence Analysis, RNA ; Transcription, Genetic ; Translocation, Genetic ; Virus Integration
    Chemical Substances DNA, Viral
    Language English
    Publishing date 2021-07-21
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 80174-4
    ISSN 1098-5514 ; 0022-538X
    ISSN (online) 1098-5514
    ISSN 0022-538X
    DOI 10.1128/JVI.00299-21
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  5. Article ; Online: Genetic analysis of the ZNF804A gene in Mexican patients with schizophrenia, schizoaffective disorder and bipolar disorder.

    Münch-Anguiano, Lucía / Camarena, Beatriz / Nieto-Quinto, Jesica / de la Torre, Patricia / Pedro Laclette, Juan / Hirata-Hernández, Harumi / Hernández-Muñoz, Sandra / Aguilar-García, Alejandro / Becerra-Palars, Claudia / Gutiérrez-Mora, Doris / Ortega-Ortiz, Hiram / Escamilla-Orozco, Raúl / Saracco-Álvarez, Ricardo / Bustos-Jaimes, Ismael

    Gene

    2022  Volume 829, Page(s) 146508

    Abstract: Background: Evidence suggests that schizophrenia (SCZ), schizoaffective disorder (SAD) and bipolar disorder (BPD) share genetic risk variants. ZNF804A gene has been associated with these disorders in different populations. GWAS and candidate gene ... ...

    Abstract Background: Evidence suggests that schizophrenia (SCZ), schizoaffective disorder (SAD) and bipolar disorder (BPD) share genetic risk variants. ZNF804A gene has been associated with these disorders in different populations. GWAS and candidate gene studies have reported association between the rs1344706 A allele with SCZ, SAD and BPD in European and Asian populations. In Mexican patients, no studies have specifically analyzed ZNF804A gene variants with these disorders. The aim of the study was to analyze the rs1344706 and identify common and rare variants in a targeted region of the ZNF804A gene in Mexican patients with SCZ, BPD and SAD compared with a control group.
    Methods: We genotyped the rs1344706 in 228 Mexican patients diagnosed with SCZ, SAD and BPD, and 295 controls. Also, an additional sample of 167 patients with these disorders and 170 controls was analyzed to identify rare and common variants using the Sanger-sequence analysis of a targeted region of ZNF804A gene.
    Results: Association analysis of rs1344706 observed a higher frequency of A allele in the patients compared with the control group; however, did not show statistical differences after Bonferronís correction (χ2 = 5.3, p = 0.0208). In the sequence analysis, we did not identify rare variants; however, we identified three common variants: rs3046266, rs1366842 and rs12477430. A comparison of the three identified variants between patients and controls did not show statistical differences (p > 0.0125). Finally, haplotype analysis did not show statistical differences between SCZ, SAD and BPD and controls.
    Conclusions: Our findings did not support the evidence suggesting that ZNF804A gene participates in the etiology of SCZ, SAD and BPD. Future studies are needed in a larger sample size to identify the effect of this gene in psychiatric disorders.
    MeSH term(s) Bipolar Disorder/genetics ; Genetic Predisposition to Disease ; Humans ; Kruppel-Like Transcription Factors/genetics ; Mexico ; Polymorphism, Single Nucleotide ; Psychotic Disorders/genetics ; Schizophrenia/genetics
    Chemical Substances Kruppel-Like Transcription Factors ; ZNF804A protein, human
    Language English
    Publishing date 2022-04-18
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 391792-7
    ISSN 1879-0038 ; 0378-1119
    ISSN (online) 1879-0038
    ISSN 0378-1119
    DOI 10.1016/j.gene.2022.146508
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  6. Article ; Online: 16p11.2 microdeletion imparts transcriptional alterations in human iPSC-derived models of early neural development

    Julien G Roth / Kristin L Muench / Aditya Asokan / Victoria M Mallett / Hui Gai / Yogendra Verma / Stephen Weber / Carol Charlton / Jonas L Fowler / Kyle M Loh / Ricardo E Dolmetsch / Theo D Palmer

    eLife, Vol

    2020  Volume 9

    Abstract: Microdeletions and microduplications of the 16p11.2 chromosomal locus are associated with syndromic neurodevelopmental disorders and reciprocal physiological conditions such as macro/microcephaly and high/low body mass index. To facilitate cellular and ... ...

    Abstract Microdeletions and microduplications of the 16p11.2 chromosomal locus are associated with syndromic neurodevelopmental disorders and reciprocal physiological conditions such as macro/microcephaly and high/low body mass index. To facilitate cellular and molecular investigations into these phenotypes, 65 clones of human induced pluripotent stem cells (hiPSCs) were generated from 13 individuals with 16p11.2 copy number variations (CNVs). To ensure these cell lines were suitable for downstream mechanistic investigations, a customizable bioinformatic strategy for the detection of random integration and expression of reprogramming vectors was developed and leveraged towards identifying a subset of ‘footprint’-free hiPSC clones. Transcriptomic profiling of cortical neural progenitor cells derived from these hiPSCs identified alterations in gene expression patterns which precede morphological abnormalities reported at later neurodevelopmental stages. Interpreting clinical information—available with the cell lines by request from the Simons Foundation Autism Research Initiative—with this transcriptional data revealed disruptions in gene programs related to both nervous system function and cellular metabolism. As demonstrated by these analyses, this publicly available resource has the potential to serve as a powerful medium for probing the etiology of developmental disorders associated with 16p11.2 CNVs.
    Keywords iPSC ; corticogenesis ; neurodevelopment ; 16p11.2 ; copy number variation ; Medicine ; R ; Science ; Q ; Biology (General) ; QH301-705.5
    Subject code 572
    Language English
    Publishing date 2020-11-01T00:00:00Z
    Publisher eLife Sciences Publications Ltd
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  7. Article ; Online: Targeting the hepatitis B cccDNA with a sequence-specific ARCUS nuclease to eliminate hepatitis B virus in vivo.

    Gorsuch, Cassandra L / Nemec, Paige / Yu, Mei / Xu, Simin / Han, Dong / Smith, Jeff / Lape, Janel / van Buuren, Nicholas / Ramirez, Ricardo / Muench, Robert C / Holdorf, Meghan M / Feierbach, Becket / Falls, Greg / Holt, Jason / Shoop, Wendy / Sevigny, Emma / Karriker, Forrest / Brown, Robert V / Joshi, Amod /
    Goodwin, Tyler / Tam, Ying K / Lin, Paulo J C / Semple, Sean C / Leatherbury, Neil / Delaney Iv, William E / Jantz, Derek / Rhoden Smith, Amy

    Molecular therapy : the journal of the American Society of Gene Therapy

    2022  Volume 30, Issue 9, Page(s) 2909–2922

    Abstract: Persistence of chronic hepatitis B (CHB) is attributed to maintenance of the intrahepatic pool of the viral covalently closed circular DNA (cccDNA), which serves as the transcriptional template for all viral gene products required for replication. ... ...

    Abstract Persistence of chronic hepatitis B (CHB) is attributed to maintenance of the intrahepatic pool of the viral covalently closed circular DNA (cccDNA), which serves as the transcriptional template for all viral gene products required for replication. Current nucleos(t)ide therapies for CHB prevent virus production and spread but have no direct impact on cccDNA or expression of viral genes. We describe a potential curative approach using a highly specific engineered ARCUS nuclease (ARCUS-POL) targeting the hepatitis B virus (HBV) genome. Transient ARCUS-POL expression in HBV-infected primary human hepatocytes produced substantial reductions in both cccDNA and hepatitis B surface antigen (HBsAg). To evaluate ARCUS-POL in vivo, we developed episomal adeno-associated virus (AAV) mouse and non-human primate (NHP) models containing a portion of the HBV genome serving as a surrogate for cccDNA. Clinically relevant delivery was achieved through systemic administration of lipid nanoparticles containing ARCUS-POL mRNA. In both mouse and NHP, we observed a significant decrease in total AAV copy number and high on-target indel frequency. In the case of the mouse model, which supports HBsAg expression, circulating surface antigen was durably reduced by 96%. Together, these data support a gene-editing approach for elimination of cccDNA toward an HBV cure.
    MeSH term(s) Animals ; Antiviral Agents ; DNA, Circular/genetics ; DNA, Viral/genetics ; Dependovirus/genetics ; Hepatitis B/therapy ; Hepatitis B Surface Antigens/genetics ; Hepatitis B Surface Antigens/therapeutic use ; Hepatitis B virus/genetics ; Hepatitis B, Chronic ; Humans ; Liposomes ; Mice ; Nanoparticles ; Virus Replication
    Chemical Substances Antiviral Agents ; DNA, Circular ; DNA, Viral ; Hepatitis B Surface Antigens ; Lipid Nanoparticles ; Liposomes
    Language English
    Publishing date 2022-05-16
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2010592-7
    ISSN 1525-0024 ; 1525-0016
    ISSN (online) 1525-0024
    ISSN 1525-0016
    DOI 10.1016/j.ymthe.2022.05.013
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  8. Article ; Online: Filoviruses utilize glycosaminoglycans for their attachment to target cells.

    Salvador, Beatriz / Sexton, Nicole R / Carrion, Ricardo / Nunneley, Jerritt / Patterson, Jean L / Steffen, Imke / Lu, Kai / Muench, Marcus O / Lembo, David / Simmons, Graham

    Journal of virology

    2013  Volume 87, Issue 6, Page(s) 3295–3304

    Abstract: Filoviruses are the cause of severe hemorrhagic fever in human and nonhuman primates. The envelope glycoprotein (GP), responsible for both receptor binding and fusion of the virus envelope with the host cell membrane, has been demonstrated to interact ... ...

    Abstract Filoviruses are the cause of severe hemorrhagic fever in human and nonhuman primates. The envelope glycoprotein (GP), responsible for both receptor binding and fusion of the virus envelope with the host cell membrane, has been demonstrated to interact with multiple molecules in order to enhance entry into host cells. Here we have demonstrated that filoviruses utilize glycosaminoglycans, and more specifically heparan sulfate proteoglycans, for their attachment to host cells. This interaction is mediated by GP and does not require the presence of the mucin domain. Both the degree of sulfation and the structure of the carbohydrate backbone play a role in the interaction with filovirus GPs. This new step of filovirus interaction with host cells can potentially be a new target for antiviral strategies. As such, we were able to inhibit filovirus GP-mediated infection using carrageenan, a broad-spectrum microbicide that mimics heparin, and also using the antiviral dendrimeric peptide SB105-A10, which interacts with heparan sulfate, antagonizing the binding of the virus to cells.
    MeSH term(s) Animals ; Cell Line ; Filoviridae/physiology ; Heparan Sulfate Proteoglycans/metabolism ; Humans ; Receptors, Virus/metabolism ; Viral Envelope Proteins/metabolism ; Virus Attachment
    Chemical Substances Heparan Sulfate Proteoglycans ; Receptors, Virus ; Viral Envelope Proteins
    Keywords covid19
    Language English
    Publishing date 2013-01-09
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 80174-4
    ISSN 1098-5514 ; 0022-538X
    ISSN (online) 1098-5514
    ISSN 0022-538X
    DOI 10.1128/JVI.01621-12
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  9. Article ; Online: Resistência de união entre cimentos e liga de níquel-cromo, em função da ciclagem térmica e variações no procedimento de união

    MARTUCI Ricardo Ruiz / MUENCH Antonio / BIANCHI Joel / RODRIGUES FILHO Leonardo Eloy

    Revista de Odontologia da Universidade de São Paulo, Vol 13, Iss 3, Pp 269-

    1999  Volume 273

    Abstract: A investigação teve a finalidade de avaliar a resistência de união de uma liga de níquel-cromo com diversos agentes cimentantes frente à imersão, sem ou com termociclagem e idade. A liga usada foi a Litecast B. Os sistemas adesivos usados foram Ketac-Cem, ...

    Abstract A investigação teve a finalidade de avaliar a resistência de união de uma liga de níquel-cromo com diversos agentes cimentantes frente à imersão, sem ou com termociclagem e idade. A liga usada foi a Litecast B. Os sistemas adesivos usados foram Ketac-Cem, Vitremer, Enforce com Flúor em três variações: a) com primer apenas (Enforce P); b) com primer e adesivo (Enforce P + A); c) apenas adesivo (Enforce A). Discos metálicos, obtidos por fundição, foram cimentados entre si, constituindo os corpos de prova, que foram imersos em água destilada e submetidos ou não à ciclagem térmica. Os testes foram feitos 1 e 90 dias após a cimentação. As conclusões foram: o Ketac-Cem apresentou baixa resistência adesiva, sendo superado pelo Vitremer; o Enforce P, embora aumentasse a resistência ao longo do tempo, fez com que ela permanecesse baixa; o Enforce P + A apresentou alta resistência em um dia, que diminuiu ao longo do tempo; o Enforce A apresentou superioridade adesiva, que se manteve ao longo do tempo com ciclagem térmica; a influência da ciclagem térmica foi dependente do sistema adesivo.
    Keywords Cimentos dentários ; Materiais dentários ; Dentistry ; RK1-715 ; Medicine ; R ; DOAJ:Dentistry ; DOAJ:Health Sciences
    Language English
    Publishing date 1999-01-01T00:00:00Z
    Publisher Universidade de São Paulo
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  10. Article ; Online: Resistência de união entre cimentos e liga de níquel-cromo, em função da ciclagem térmica e variações no procedimento de união Tensile bond strength between cements and nickel-chromium alloy related to thermocycling and adhesive variations

    Ricardo Ruiz MARTUCI / Antonio MUENCH / Joel BIANCHI / Leonardo Eloy RODRIGUES FILHO

    Revista de Odontologia da Universidade de São Paulo, Vol 13, Iss 3, Pp 269-

    1999  Volume 273

    Abstract: A investigação teve a finalidade de avaliar a resistência de união de uma liga de níquel-cromo com diversos agentes cimentantes frente à imersão, sem ou com termociclagem e idade. A liga usada foi a Litecast B. Os sistemas adesivos usados foram Ketac-Cem, ...

    Abstract A investigação teve a finalidade de avaliar a resistência de união de uma liga de níquel-cromo com diversos agentes cimentantes frente à imersão, sem ou com termociclagem e idade. A liga usada foi a Litecast B. Os sistemas adesivos usados foram Ketac-Cem, Vitremer, Enforce com Flúor em três variações: a) com primer apenas (Enforce P); b) com primer e adesivo (Enforce P + A); c) apenas adesivo (Enforce A). Discos metálicos, obtidos por fundição, foram cimentados entre si, constituindo os corpos de prova, que foram imersos em água destilada e submetidos ou não à ciclagem térmica. Os testes foram feitos 1 e 90 dias após a cimentação. As conclusões foram: o Ketac-Cem apresentou baixa resistência adesiva, sendo superado pelo Vitremer; o Enforce P, embora aumentasse a resistência ao longo do tempo, fez com que ela permanecesse baixa; o Enforce P + A apresentou alta resistência em um dia, que diminuiu ao longo do tempo; o Enforce A apresentou superioridade adesiva, que se manteve ao longo do tempo com ciclagem térmica; a influência da ciclagem térmica foi dependente do sistema adesivo. We evaluated tensile bond strengths between a nickel-chromium alloy and cements at different times (one and 90 days) using or not thermocycling. Alloy used was Litecast B, and luting cements were Ketac-Cem, Vitremer, and Fluoride Enforce with three variations: a) only primer; b) with primer and bond; c) only with bond. Metallic discs with 6 mm diameter were cemented together and immersed in distilled water. Half specimens were thermocycled and half one not. Conclusions were: Ketac-Cem presented low bonding strength, being that of Vitremer very higher; the material Enforce when used only with primer increased adhesion with time but yet remained relatively low after 90 days; Enforce used with bond only achieved superior adhesion, still present specially with termocycling after 90 days; influence of thermocycling depends on adhesive system.
    Keywords Cimentos dentários ; Materiais dentários ; Dental cements ; Dental materials ; Dentistry ; RK1-715 ; Medicine ; R ; DOAJ:Dentistry ; DOAJ:Health Sciences
    Language English
    Publishing date 1999-07-01T00:00:00Z
    Publisher Universidade de São Paulo
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

To top