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1.
Clin Neuropsychol ; : 1-23, 2022 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-35043752

RESUMO

To provide education regarding the critical importance of test security for neuropsychological and psychological tests, and to establish recommendations for best practices for maintaining test security in forensic, clinical, teaching, and research settings. Previous test security guidelines were not adequately specified. METHOD: Neuropsychologists practicing in a broad range of settings collaborated to develop detailed and specific guidance regarding test security to best ensure continued viability of neuropsychological and psychological tests. Implications of failing to maintain test security for both the practice of neuropsychology and for society at large were identified. Types of test data that can be safely disclosed to nonpsychologists are described.Specific procedures can be followed that will minimize risk of invalidating future use of neuropsychological and psychological measures.Clinical neuropsychologists must commit to protecting sensitive neuropsychological and psychological test information from exposure to nonpsychologists, and now have specific recommendations that will guide that endeavor.

2.
Int J Mol Sci ; 22(12)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34207218

RESUMO

Resin-based composite materials have been widely used in restorative dental materials due to their aesthetic, mechanical, and physical properties. However, they still encounter clinical shortcomings mainly due to recurrent decay that develops at the composite-tooth interface. The low-viscosity adhesive that bonds the composite to the tooth is intended to seal this interface, but the adhesive seal is inherently defective and readily damaged by acids, enzymes, and oral fluids. Bacteria infiltrate the resulting gaps at the composite-tooth interface and bacterial by-products demineralize the tooth and erode the adhesive. These activities lead to wider and deeper gaps that provide an ideal environment for bacteria to proliferate. This complex degradation process mediated by several biological and environmental factors damages the tooth, destroys the adhesive seal, and ultimately, leads to failure of the composite restoration. This paper describes a co-tethered dual peptide-polymer system to address composite-tooth interface vulnerability. The adhesive system incorporates an antimicrobial peptide to inhibit bacterial attack and a hydroxyapatite-binding peptide to promote remineralization of damaged tooth structure. A designer spacer sequence was incorporated into each peptide sequence to not only provide a conjugation site for methacrylate (MA) monomer but also to retain active peptide conformations and enhance the display of the peptides in the material. The resulting MA-antimicrobial peptides and MA-remineralization peptides were copolymerized into dental adhesives formulations. The results on the adhesive system composed of co-tethered peptides demonstrated both strong metabolic inhibition of S. mutans and localized calcium phosphate remineralization. Overall, the result offers a reconfigurable and tunable peptide-polymer hybrid system as next-generation adhesives to address composite-tooth interface vulnerability.


Assuntos
Antibacterianos/química , Cimentos Dentários/química , Proteínas Citotóxicas Formadoras de Poros/química , Antibacterianos/farmacologia , Resinas Compostas/química , Resinas Compostas/farmacologia , Cimentos Dentários/farmacologia , Metacrilatos/química , Proteínas Citotóxicas Formadoras de Poros/farmacologia , Streptococcus mutans/efeitos dos fármacos , Remineralização Dentária/métodos
3.
Clin Neuropsychol ; : 1-19, 2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34311662

RESUMO

OBJECTIVE: To cross-validate RAVLT performance validity cut-offs and the RAVLT/RO discriminant function in a large neuropsychological sample. METHOD: RAVLT scores and the RAVLT/RO discriminant function were compared in credible (n = 100) and noncredible (n = 353) neuropsychology referrals. RESULTS: Noncredible patients scored lower than credible patients on RAVLT scores and the RAVLT/RO discriminant function. With cut-offs set to ≥90% specificity, highest sensitivities were observed for the discriminant function (cut-off ≤.064; 55.8%), recognition total (cut-off ≤9; 53.1%), the recognition combination score (≤10; 47.7%), and total learning across trials (cut-off ≤31; 45.3%). Individuals with histories of learning difficulties were over-represented in the 10% of credible patients exceeding cut-offs. When these individuals were removed, cut-offs could be tightened while still maintaining at least 90% specificity, and thereby increasing sensitivity (e.g., recognition total cut-off ≤10, 65% sensitivity; RAVLT/RO discriminant function cut-off ≤.176, 58% sensitivity). When three of the most sensitive, non-overlapping scores were considered in combination, 17% of credible patients failed ≥1 of the three cut-offs, while 3% failed two, and only 1% failed all three. In contrast, in the noncredible sample, more than two-thirds failed one or more of the three cut-offs, nearly half failed ≥2, and nearly a quarter failed all three. CONCLUSIONS: RAVLT PVT cut-offs and the RAVLT/RO discriminant function achieve approximately 50% sensitivity, and approach 65% sensitivity when cut-offs specific to samples without histories of learning problems are employed, confirming that RAVLT cut-offs and the RAVLT/RO discriminant function continue to be valuable techniques in the identification of performance invalidity.

4.
BMC Bioinformatics ; 22(1): 239, 2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-33975547

RESUMO

BACKGROUND: Current methods in machine learning provide approaches for solving challenging, multiple constraint design problems. While deep learning and related neural networking methods have state-of-the-art performance, their vulnerability in decision making processes leading to irrational outcomes is a major concern for their implementation. With the rising antibiotic resistance, antimicrobial peptides (AMPs) have increasingly gained attention as novel therapeutic agents. This challenging design problem requires peptides which meet the multiple constraints of limiting drug-resistance in bacteria, preventing secondary infections from imbalanced microbial flora, and avoiding immune system suppression. AMPs offer a promising, bioinspired design space to targeting antimicrobial activity, but their versatility also requires the curated selection from a combinatorial sequence space. This space is too large for brute-force methods or currently known rational design approaches outside of machine learning. While there has been progress in using the design space to more effectively target AMP activity, a widely applicable approach has been elusive. The lack of transparency in machine learning has limited the advancement of scientific knowledge of how AMPs are related among each other, and the lack of general applicability for fully rational approaches has limited a broader understanding of the design space. METHODS: Here we combined an evolutionary method with rough set theory, a transparent machine learning approach, for designing antimicrobial peptides (AMPs). Our method achieves the customization of AMPs using supervised learning boundaries. Our system employs in vitro bacterial assays to measure fitness, codon-representation of peptides to gain flexibility of sequence selection in DNA-space with a genetic algorithm and machine learning to further accelerate the process. RESULTS: We use supervised machine learning and a genetic algorithm to find a peptide active against S. epidermidis, a common bacterial strain for implant infections, with an improved aggregation propensity average for an improved ease of synthesis. CONCLUSIONS: Our results demonstrate that AMP design can be customized to maintain activity and simplify production. To our knowledge, this is the first time when codon-based genetic algorithms combined with rough set theory methods is used for computational search on peptide sequences.


Assuntos
Peptídeos Catiônicos Antimicrobianos , Aprendizado de Máquina , Sequência de Aminoácidos , Resistência Microbiana a Medicamentos , Proteínas Citotóxicas Formadoras de Poros
5.
Clin Neuropsychol ; 35(6): 1053-1106, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33823750

RESUMO

Objective: Citation and download data pertaining to the 2009 AACN consensus statement on validity assessment indicated that the topic maintained high interest in subsequent years, during which key terminology evolved and relevant empirical research proliferated. With a general goal of providing current guidance to the clinical neuropsychology community regarding this important topic, the specific update goals were to: identify current key definitions of terms relevant to validity assessment; learn what experts believe should be reaffirmed from the original consensus paper, as well as new consensus points; and incorporate the latest recommendations regarding the use of validity testing, as well as current application of the term 'malingering.' Methods: In the spring of 2019, four of the original 2009 work group chairs and additional experts for each work group were impaneled. A total of 20 individuals shared ideas and writing drafts until reaching consensus on January 21, 2021. Results: Consensus was reached regarding affirmation of prior salient points that continue to garner clinical and scientific support, as well as creation of new points. The resulting consensus statement addresses definitions and differential diagnosis, performance and symptom validity assessment, and research design and statistical issues. Conclusions/Importance: In order to provide bases for diagnoses and interpretations, the current consensus is that all clinical and forensic evaluations must proactively address the degree to which results of neuropsychological and psychological testing are valid. There is a strong and continually-growing evidence-based literature on which practitioners can confidently base their judgments regarding the selection and interpretation of validity measures.


Assuntos
Simulação de Doença , Neuropsicologia , Academias e Institutos , Humanos , Motivação , Testes Neuropsicológicos , Estados Unidos
6.
J Mech Behav Biomed Mater ; 113: 104135, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33160267

RESUMO

Resin-based composite has overtaken dental amalgam as the most popular material for the repair of lost or damaged tooth structure. In spite of the popularity, the average composite lifetime is about half that of amalgam restorations. The leading cause of composite-restoration failure is decay at the margin where the adhesive is applied. The adhesive is intended to seal the composite/tooth interface, but the adhesive seal to dentin is fragile and readily degraded by acids, enzymes and other oral fluids. The inherent weakness of this material system is attributable to several factors including the lack of antimicrobial properties, remineralization capabilities and durable mechanical performance - elements that are central to the integrity of the adhesive/dentin (a/d) interfacial seal. Our approach to this problem offers a transition from a hybrid to a biohybrid structure. Discrete peptides are tethered to polymers to provide multi-bio-functional adhesive formulations that simultaneously achieve antimicrobial and remineralization properties. The bio-additive materials design combines several functional properties with the goal of providing an adhesive that will serve as a durable barrier to recurrent decay at the composite/tooth interface. This article provides an overview of our multi-faceted approach which uses peptides tethered to polymers and new polymer chemistries to achieve the next generation adhesive system - an adhesive that provides antimicrobial properties, repair of defective dentin and enhanced mechanical performance.


Assuntos
Adesivos , Colagem Dentária , Resinas Compostas , Restauração Dentária Permanente , Dentina , Cimentos de Resina
7.
PLoS One ; 15(10): e0241250, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33119652

RESUMO

With the advent of highly sensitive technologies such as tandem mass spectrometry and next-generation sequencing, recombinant antibodies are now routinely analyzed for the presence of low-level sequence variants including amino acid misincorporations. During mAb cell culture process development, we found that proline was replaced with the non-canonical amino acid, hydroxyproline, in the protein sequence. We investigated the relationship between proline content in the cell culture media and proline sequence variants and found that the proline concentration was inversely correlated with the amount of sequence variants detected in the protein sequence. Hydroxyproline incorporation has been previously reported in recombinant proteins produced in mammalian expression systems as a post-translational modification. Given the dependency on proline levels, the mechanism was then investigated. To address the possibility of co-translational misincorporation of hydroxyproline, we used tandem mass spectrometry to measure incorporation of stable-isotope labelled hydroxyproline added to the feed of a production bioreactor. We discovered co-translational misincorporation of labelled hydroxyproline in the recombinant antibody. These findings are significant, since they underscore the need to track non-canonical amino acid incorporation as a co-translational event in CHO cells. Understanding the mechanism of hydroxyproline incorporation is crucial in developing an appropriate control strategy during biologics production.


Assuntos
Anticorpos Monoclonais/biossíntese , Reatores Biológicos , Hidroxiprolina/metabolismo , Processamento de Proteína Pós-Traducional , Animais , Anticorpos Monoclonais/genética , Células CHO , Cricetulus , Hidroxiprolina/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética
8.
ACS Appl Polym Mater ; 2(3): 1134-1144, 2020 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-33834166

RESUMO

Bacterial adhesion and growth at the composite/adhesive/tooth interface remain the primary cause of dental composite restoration failure. Early colonizers, including Streptococcus mutans, play a critical role in the formation of dental caries by creating an environment that reduces the adhesive's integrity. Subsequently, other bacterial species, biofilm formation, and lactic acid from S. mutans demineralize the adjoining tooth. Because of their broad spectrum of antibacterial activity and low risk for antibiotic resistance, antimicrobial peptides (AMPs) have received significant attention to prevent bacterial biofilms. Harnessing the potential of AMPs is still very limited in dentistry-a few studies have explored peptide-enabled antimicrobial adhesive copolymer systems using mainly nonspecific adsorption. In the current investigation, to avoid limitations from nonspecific adsorption and to prevent potential peptide leakage out of the resin, we conjugated an AMP with a commonly used monomer for dental adhesive formulation. To tailor the flexibility between the peptide and the resin material, we designed two different spacer domains. The spacer-integrated antimicrobial peptides were conjugated to methacrylate (MA), and the resulting MA-AMP monomers were next copolymerized into dental adhesives as AMP-polymer conjugates. The resulting bioactivity of the polymethacrylate-based AMP conjugated matrix activity was investigated. The antimicrobial peptide conjugated to the resin matrix demonstrated significant antimicrobial activity against S. mutans. Secondary structure analyses of conjugated peptides were applied to understand the activity differential. When mechanical properties of the adhesive system were investigated with respect to AMP and cross-linking concentration, resulting AMP-polymer conjugates maintained higher compressive moduli compared to hydrogel analogues including polyHEMA. Overall, our result provides a robust approach to develop a fine-tuned bioenabled peptide adhesive system with improved mechanical properties and antimicrobial activity. The results of this study represent a critical step toward the development of peptide-conjugated dentin adhesives for treatment of secondary caries and the enhanced durability of dental composite restorations.

9.
Front Psychol ; 10: 1650, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31396127

RESUMO

Objective: Here we report an investigation on the accuracy of the b Test, a measure to identify malingering of cognitive symptoms, in detecting malingerers of mild cognitive impairment. Method: Three groups of participants, patients with Mild Neurocognitive Disorder (n = 21), healthy elders (controls, n = 21), and healthy elders instructed to simulate mild cognitive disorder (malingerers, n = 21) were administered two background neuropsychological tests (MMSE, FAB) as well as the b Test. Results: Malingerers performed significantly worse on all error scores as compared to patients and controls, and performed poorly than controls, but comparably to patients, on the time score. Patients performed significantly worse than controls on all scores, but both groups showed the same pattern of more omission than commission errors. By contrast, malingerers exhibited the opposite pattern with more commission errors than omission errors. Machine learning models achieve an overall accuracy higher than 90% in distinguishing patients from malingerers on the basis of b Test results alone. Conclusions: Our findings suggest that b Test error scores accurately distinguish patients with Mild Neurocognitive Disorder from malingerers and may complement other validated procedures such as the Medical Symptom Validity Test.

10.
J Biomed Mater Res B Appl Biomater ; 107(8): 2673-2683, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30895695

RESUMO

Nearly 100 million of the 170 million composite and amalgam restorations placed annually in the United States are replacements for failed restorations. The primary reason both composite and amalgam restorations fail is recurrent decay, for which composite restorations experience a 2.0-3.5-fold increase compared to amalgam. Recurrent decay is a pernicious problem-the standard treatment is replacement of defective composites with larger restorations that will also fail, initiating a cycle of ever-larger restorations that can lead to root canals, and eventually, to tooth loss. Unlike amalgam, composite lacks the inherent capability to seal discrepancies at the restorative material/tooth interface. The low-viscosity adhesive that bonds the composite to the tooth is intended to seal the interface, but the adhesive degrades, which can breach the composite/tooth margin. Bacteria and bacterial by-products such as acids and enzymes infiltrate the marginal gaps and the composite's inability to increase the interfacial pH facilitates cariogenic and aciduric bacterial outgrowth. Together, these characteristics encourage recurrent decay, pulpal damage, and composite failure. This review article examines key biological and physicochemical interactions involved in the failure of composite restorations and discusses innovative strategies to mitigate the negative effects of pathogens at the adhesive/dentin interface. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B:2466-2475, 2019.


Assuntos
Adesivos , Materiais Dentários , Restauração Dentária Permanente , Dentina , Adesivos/química , Adesivos/uso terapêutico , Materiais Dentários/química , Materiais Dentários/uso terapêutico , Dentina/química , Dentina/metabolismo , Humanos
11.
Appl Sci (Basel) ; 9(3)2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33542835

RESUMO

The most common cause for dental composite failures is secondary caries due to invasive bacterial colonization of the adhesive/dentin (a/d) interface. Innate material weakness often lead to an insufficient seal between the adhesive and dentin. Consequently, bacterial by-products invade the porous a/d interface leading to material degradation and dental caries. Current approaches to achieve antibacterial properties in these materials continue to raise concerns regarding hypersensitivity and antibiotic resistance. Herein, we have developed a multi-faceted, bio-functionalized approach to overcome the vulnerability of such interfaces. An antimicrobial adhesive formulation was designed using a combination of antimicrobial peptide and a ε-polylysine resin system. Effector molecules boasting innate immunity are brought together with a biopolymer offering a two-fold biomimetic design approach. The selection of ε-polylysine was inspired due to its non-toxic nature and common use as food preservative. Biomolecular characterization and functional activity of our engineered dental adhesive formulation were assessed and the combinatorial formulation demonstrated significant antimicrobial activity against Streptococcus mutans. Our antimicrobial peptide-hydrophilic adhesive hybrid system design offers advanced, biofunctional properties at the critical a/d interface.

13.
Mater Sci Eng C Mater Biol Appl ; 94: 333-343, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30423715

RESUMO

Bacterial infection is a serious medical problem leading to implant failure. The current antibiotic based therapies rise concerns due to bacterial resistance. The family of antimicrobial peptides (AMP) is one of the promising candidates as local therapy agents due to their broad-spectrum activity. Despite AMPs receive increasing attention to treat infection, their effective delivery to the implantation site has been limited. Here, we developed an engineered dual functional peptide which delivers AMP as a biomolecular therapeutic agent onto calcium phosphate (Ca-P) deposited nanotubular titanium surfaces. Dual functionality of the peptide was achieved by combining a hydroxyapatite binding peptide-1 (HABP1) with an AMP using a flexible linker. HABP functionality of the peptide provided a self-coating property onto the nano-topographies that are designed to improve osteointegration capability, while AMP offered an antimicrobial protection onto the implant surface. We successfully deposited calcium phosphate minerals on nanotubular titanium oxide surface using pulse electrochemical deposition (PECD) and characterized the minerals by XRD, FT-IR, FE-SEM. Antimicrobial activity of the engineered peptide was tested against S. mutans (gram- positive) and E. coli (gram-negative) both in solution and on the Ca-P coated nanotubular titanium surface. In solution activity of AMP and dual functional peptide have the same Minimum Inhibitory Concentration (MIC) (32 mg/mL). The peptide also resulted in the reduction of the number of bacteria both for E.coli and S. mutans compare to control groups on the surface. Antimicrobial features of dual functional peptides are strongly correlated with their structures suggesting tunability in design through linkers regions. The dual-function peptide offers single-step solution for implant surface functionalization that could be applicable to any implant surface having different topographies.


Assuntos
Anti-Infecciosos/farmacologia , Fosfatos de Cálcio/química , Materiais Revestidos Biocompatíveis/química , Nanotubos/química , Peptídeos/farmacologia , Titânio/química , Sequência de Aminoácidos , Aderência Bacteriana/efeitos dos fármacos , Durapatita/química , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Nanotubos/ultraestrutura , Peptídeos/química , Estrutura Secundária de Proteína , Staphylococcus aureus/efeitos dos fármacos
14.
Arch Clin Neuropsychol ; 34(8): 1367-1380, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-30395181

RESUMO

OBJECTIVE: Evaluate the effectiveness of Rey 15-item plus recognition data in a large neuropsychological sample. METHOD: Rey 15-item plus recognition scores were compared in credible (n = 138) and noncredible (n = 353) neuropsychology referrals. RESULTS: Noncredible patients scored significantly worse than credible patients on all Rey 15-item plus recognition scores. When cut-offs were selected to maintain at least 89.9% specificity, cut-offs could be made more stringent, with the highest sensitivity found for recognition correct (cut-off ≤11; 62.6% sensitivity) and the combination score (recall + recognition - false positives; cut-off ≤22; 60.6% sensitivity), followed by recall correct (cut-off ≤11; 49.3% sensitivity), and recognition false positive errors (≥3; 17.9% sensitivity). A cut-off of ≥4 applied to a summed qualitative error score for the recall trial resulted in 19.4% sensitivity. Approximately 10% of credible subjects failed either recall correct or recognition correct, whereas two-thirds of noncredible patients (67.7%) showed this pattern. Thirteen percent of credible patients failed either recall correct, recognition correct, or the recall qualitative error score, whereas nearly 70% of noncredible patients failed at least one of the three. Some individual qualitative recognition errors had low false positive rates (<2%) indicating that their presence was virtually pathognomonic for noncredible performance. Older age (>50) and IQ < 80 were associated with increased false positive rates in credible patients. CONCLUSIONS: Data on a larger sample than that available in the 2002 validation study show that Rey 15-item plus recognition cut-offs can be made more stringent, and thereby detect up to 70% of noncredible test takers, but the test should be used cautiously in older individuals and in individuals with lowered IQ.


Assuntos
Rememoração Mental , Testes Neuropsicológicos/estatística & dados numéricos , Reconhecimento Psicológico , Adolescente , Adulto , Fatores Etários , Idoso , Reações Falso-Positivas , Feminino , Humanos , Masculino , Simulação de Doença/diagnóstico , Simulação de Doença/psicologia , Pessoa de Meia-Idade , Desempenho Psicomotor , Valores de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
15.
BMC Bioinformatics ; 19(1): 469, 2018 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-30522443

RESUMO

BACKGROUND: Antimicrobial peptides attract considerable interest as novel agents to combat infections. Their long-time potency across bacteria, viruses and fungi as part of diverse innate immune systems offers a solution to overcome the rising concerns from antibiotic resistance. With the rapid increase of antimicrobial peptides reported in the databases, peptide selection becomes a challenge. We propose similarity analyses to describe key properties that distinguish between active and non-active peptide sequences building upon the physicochemical properties of antimicrobial peptides. We used an iterative supervised machine learning approach to classify active peptides from inactive peptides with low false discovery rates in a relatively short computational search time. RESULTS: By generating explicit boundaries, our method defines new categories of active and inactive peptides based on their physicochemical properties. Consequently, it describes physicochemical characteristics of similarity among active peptides and the physicochemical boundaries between active and inactive peptides in a single process. To build the similarity boundaries, we used the rough set theory approach; to our knowledge, this is the first time that this approach has been used to classify peptides. The modified rough set theory method limits the number of values describing a boundary to a user-defined limit. Our method is optimized for specificity over selectivity. Noting that false positives increase activity assays while false negatives only increase computational search time, our method provided a low false discovery rate. Published datasets were used to compare our rough set theory method to other published classification methods and based on this comparison, we achieved high selectivity and comparable sensitivity to currently available methods. CONCLUSIONS: We developed rule sets that define physicochemical boundaries which allow us to directly classify the active sequences from inactive peptides. Existing classification methods are either sequence-order insensitive or length-dependent, whereas our method generates the rule sets that combine order-sensitive descriptors with length-independent descriptors. The method provides comparable or improved performance to currently available methods. Discovering the boundaries of physicochemical properties may lead to a new understanding of peptide similarity.


Assuntos
Peptídeos Catiônicos Antimicrobianos/classificação , Fenômenos Químicos , Peptídeos Catiônicos Antimicrobianos/metabolismo , Modelos Moleculares
16.
Dent Mater ; 34(11): 1652-1660, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30201287

RESUMO

OBJECTIVES: The objective of this study was to explore the effect of lysine integration to dental adhesives with respect to the polymerization kinetics, neutralization capacities in the acidic microenvironment, dynamic mechanical properties, and thermal properties. MATERIALS AND METHOD: Lysine was incorporated into liquid resin formulations at 2.5 and 5.0wt % with additional water/ethanol co-solvents. The co-monomer system contained 2-hydroxyethyl-methacrylate (HEMA) and Bisphenol A glycerolate dimethacrylate (BisGMA) with a mass ratio of 45/55. The kinetics of photopolymerization, neutralization capacities, lysine-leaching, dynamic mechanical properties and thermal properties of the control and experimental adhesives were analyzed. RESULTS: The degree of conversion of the experimental adhesive was increased substantially at 2.5wt% lysine as compared to the control. The experimental polymers provided acute neutralization of the acidic microenvironment. Approximately half of the lysine was released from the polymer network within one month. Under dry conditions and physiologic temperatures, the incorporation of lysine did not compromise the storage modulus. Comparison of the thermal properties suggests that the more compact structure of the control adhesive inhibits movement of the polymer chains resulting in increased Tg. SIGNIFICANCE: Incorporating lysine in the adhesive formulations led to promising results regarding modulating pH, which may serve as one aspect of a multi-spectrum approach for enhancing the durability of composite restorations. The results provide insight and lay a foundation for incorporating amino acids or peptides into adhesive formulations for pH modulation or desired bioactivity at the interfacial margin between the composite and tooth.


Assuntos
Cimentos Dentários/química , Lisina/química , Bis-Fenol A-Glicidil Metacrilato/química , Etanol/química , Concentração de Íons de Hidrogênio , Cinética , Teste de Materiais , Metacrilatos/química , Polimerização , Polímeros/química
17.
Clin Neuropsychol ; 32(6): 1054-1067, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29345192

RESUMO

OBJECTIVE: To cross-validate the Dot Counting Test in a large neuropsychological sample. METHOD: Dot Counting Test scores were compared in credible (n = 142) and non-credible (n = 335) neuropsychology referrals. RESULTS: Non-credible patients scored significantly higher than credible patients on all Dot Counting Test scores. While the original E-score cut-off of ≥17 achieved excellent specificity (96.5%), it was associated with mediocre sensitivity (52.8%). However, the cut-off could be substantially lowered to ≥13.80, while still maintaining adequate specificity (≥90%), and raising sensitivity to 70.0%. Examination of non-credible subgroups revealed that Dot Counting Test sensitivity in feigned mild traumatic brain injury (mTBI) was 55.8%, whereas sensitivity was 90.6% in patients with non-credible cognitive dysfunction in the context of claimed psychosis, and 81.0% in patients with non-credible cognitive performance in depression or severe TBI. Thus, the Dot Counting Test may have a particular role in detection of non-credible cognitive symptoms in claimed psychiatric disorders. Alternative to use of the E-score, failure on ≥1 cut-offs applied to individual Dot Counting Test scores (≥6.0″ for mean grouped dot counting time, ≥10.0″ for mean ungrouped dot counting time, and ≥4 errors), occurred in 11.3% of the credible sample, while nearly two-thirds (63.6%) of the non-credible sample failed one of more of these cut-offs. CONCLUSIONS: An E-score cut-off of 13.80, or failure on ≥1 individual score cut-offs, resulted in few false positive identifications in credible patients, and achieved high sensitivity (64.0-70.0%), and therefore appear appropriate for use in identifying neurocognitive performance invalidity.


Assuntos
Transtornos Mentais/diagnóstico , Transtornos Mentais/psicologia , Testes Neuropsicológicos/normas , Encaminhamento e Consulta/normas , Adolescente , Adulto , Idoso , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/psicologia , Feminino , Humanos , Masculino , Simulação de Doença/diagnóstico , Simulação de Doença/psicologia , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Adulto Jovem
18.
Clin Neuropsychol ; 32(1): 165-182, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28585455

RESUMO

OBJECTIVE: The current study evaluated MSPQ sensitivity to noncredible PVT performance in the context of external incentive, and examined MSPQ false positive rates in noncompensation-seeking neuropsychology patients; and investigated effects of ethnicity/culture, gender, and somatoform diagnosis on MSPQ scores, and relationships with PVT and MMPI-2-RF data. METHOD: MSPQ scores were compared in credible (n = 110) and noncredible (n = 153) neuropsychology referrals. RESULTS: Noncredible patients scored higher than credible patients. When the credible group was divided into those with somatoform orientation (n = 39) versus those without (n = 71), the credible nonsomatoform group scored lower than the other two groups, who did not differ from each other. MSPQ elevations were found in ethnic minorities, and in individuals who learned English as a second language or concurrently with another language. MSPQ elevations were also associated with chronic systemic diseases, neurologic illness, and substance abuse. Women scored higher than men, but men and women were equally represented among those patients scoring beyond cut-offs. MSPQ scores were minimally related to PVT data but were more strongly correlated with MMPI-2-RF scales, particularly over-report validity scales, RC1, and Somatic/Cognitive scales, with more widespread relationships observed in noncredible patients. CONCLUSIONS: A cut-off of 18 resulted in few false positives in credible nonsomatoform patients, and appears appropriate for identifying physical symptom over-report (due to malingering or somatoform orientations), with associated sensitivity of 29%. However, clinicians are cautioned regarding using the MSPQ in patients with systemic, neurologic, and substance abuse conditions, and in ethnic minorities and non-monolingual English-speakers.


Assuntos
Simulação de Doença/diagnóstico , Testes Neuropsicológicos , Transtornos Somatoformes/diagnóstico , Inquéritos e Questionários , Adulto , Doença Crônica , Características Culturais , Avaliação da Deficiência , Feminino , Humanos , Masculino , Simulação de Doença/etnologia , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Fatores Sexuais , Transtornos Somatoformes/etnologia
19.
Clin Neuropsychol ; 31(8): 1401-1405, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28994350

RESUMO

We reply to Nichols' (2017) critique of our commentary on the MMPI-2/MMPI-2-RF Symptom Validity Scale (FBS/FBS-r) as a measure of symptom exaggeration versus a measure of litigation response syndrome (LRS). Nichols claims that we misrepresented the thrust of the original paper he co-authored with Gass; namely, that they did not represent that the FBS/FBS-r were measures of LRS but rather, intended to convey that the FBS/RBS-r were indeterminate as to whether the scales measured LRS or measured symptom exaggeration. Our original commentary offered statistical support from published literature that (1) FBS/FBS-r were associated with performance validity test (PVT) failure, establishing the scales as measures of symptom exaggeration, and (2) persons in litigation who passed PVTs did not produce clinically significant elevations on the scales, contradicting that FBS/FBS-r were measures of LRS. In the present commentary, we draw a distinction between the psychometric data we present supporting the validity of FBS/FBS-r, and the conceptual, non-statistical arguments presented by Nichols, who does not refute our original empirically based conclusions.


Assuntos
MMPI , Simulação de Doença , Humanos , Masculino , Testes Neuropsicológicos , Psicometria , Reprodutibilidade dos Testes
20.
Clin Neuropsychol ; 31(8): 1387-1395, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28829224

RESUMO

OBJECTIVES: To address (1) Whether there is empirical evidence for the contention of Nichols and Gass that the MMPI-2/MMPI-2-RF FBS/FBS-r Symptom Validity Scale is a measure of Litigation Response Syndrome (LRS), representing a credible set of responses and reactions of claimants to the experience of being in litigation, rather than a measure of non-credible symptom report, as the scale is typically used; and (2) to address their stated concerns about the validity of FBS/FBS-r meta-analytic results, and the risk of false positive elevations in persons with bona-fide medical conditions. METHOD: Review of published literature on the FBS/FBS-r, focusing in particular on associations between scores on this symptom validity test and scores on performance validity tests (PVTs), and FBS/FBS-r score elevations in patients with genuine neurologic, psychiatric and medical problems. RESULTS: (1) several investigations show significant associations between FBS/FBS-r scores and PVTs measuring non-credible performance; (2) litigants who pass PVTs do not produce significant elevations on FBS/FBS-r; (3) non-litigating medical patients (bariatric surgery candidates, persons with sleep disorders, and patients with severe traumatic brain injury) who have multiple physical, emotional and cognitive symptoms do not produce significant elevations on FBS/FBS-r. Two meta-analytic studies show large effect sizes for FBS/FBS-r of similar magnitude. CONCLUSIONS: FBS/FBS-r measures non-credible symptom report rather than legitimate experience of litigation stress. Importantly, the absence of significant FBS/FBS-r elevations in litigants who pass PVTs demonstrating credible performance, directly contradicts the contention of Nichols and Gass that the scale measures LRS. These data, meta-analytic publications, and recent test use surveys support the admissibility of FBS/FBS-r under both Daubert and the older Frye criteria.


Assuntos
Simulação de Doença , Transtornos do Sono-Vigília , Humanos , MMPI , Testes Neuropsicológicos , Reprodutibilidade dos Testes
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