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1.
Telemed Rep ; 2(1): 264-272, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35720751

RESUMO

Background: Cervical cancer, a preventable cancer of disparities, is the primary cause of cancer death for women in Nicaragua. Clinics and personnel in rural and remote Nicaragua may not be accessible to perform recommended screening or follow-up services. Objective: To assess acceptability and feasibility of integrating innovations for high-quality screening and treatment follow-up (tele-colposcopy) into existing pathways on Nicaragua's Caribbean Coast within the context of the National Cervical Cancer Control Program. Methods: Provider focus groups, key informant interviews, and environmental scans were conducted for 13 clinics on the Caribbean Coast of Nicaragua. Topics discussed included a smartphone-based mobile colposcope (MobileODT hardware and mobile platform), mobile connectivity capacity, clinic resources, provider acceptability, and current diagnostic and clinical protocols. We tested device connectivity through image upload availability and real-time video connection and simulated clinical encounters utilizing MobileODT and a low-cost cervical simulator. We developed a database of colposcopic images to establish feasibility of integrating this database and clinical characteristics into the cervical cancer registry. Results: Provider acceptability of integrating tele-colposcopy into existing cancer control efforts was high. Image upload connectivity varied by location (mean = 1 h 9 min). Most clinics had running water (84.6%) and consistent electricity (92.3%), but some did not have access to landline telephones (53.8%). Conclusions: As faster connectivity becomes available in remote settings, Mobile Health tools such as tele-colposcopy will be increasingly feasible to provide access to high-quality cervical cancer follow-up. World Health Organization guidance on integrating technology into existing programs will remain important to ensure programmatic efficacy, local relevance, and sustainability.

4.
J Cancer Surviv ; 14(5): 643-652, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32390103

RESUMO

PURPOSE: Rural cancer survivors have worse quality of life than their urban counterparts. Telemedicine is a potential solution to connecting rural residents with specialized cancer providers during the survivorship period, but limitations in broadband may stifle the impact. Using data from a feasibility study evaluating a telemedicine intervention aimed at connecting rural Virginia cancer survivors with their care team located at a cancer center associated with an academic medical center, we sought to evaluate the ability of rural survivors to access the intervention and suggest strategies for improving access to rural cancer survivorship care. METHODS: We used a descriptive design with geospatial and quantitative methods to understand broadband access, driving time to a satellite telemedicine site, and ability to utilize a borrowed cellular-enabled tablet to participate in the intervention for cancer survivors living in Central Virginia. RESULTS: Our study participants resided in census tracts where an average of 58% of households have adequate broadband access necessary to support a telemedicine videoconferencing intervention. Average driving time to the nearest telemedicine site was 29.6 min. Those who utilized the borrowed tablet experienced considerable difficulty with utilizing the technology. CONCLUSIONS: Rural cancer populations do not have equal access to a cancer survivorship telemedicine intervention. IMPLICATIONS FOR CANCER SURVIVORS: Telemedicine interventions aimed at connecting cancer survivors with their academic medical center-based cancer providers may be ineffective if survivors do not have access to either fixed broadband or a satellite clinic. Future research needs to evaluate other sites from which rural survivors can connect, such as rural public libraries.


Assuntos
Sobreviventes de Câncer/estatística & dados numéricos , Exclusão Digital/tendências , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Disparidades em Assistência à Saúde/estatística & dados numéricos , Acesso à Internet/estatística & dados numéricos , Neoplasias/terapia , Telemedicina/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , População Rural , Sobrevivência
5.
Oncogene ; 38(18): 3402-3414, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30643193

RESUMO

The type III TGF-ß receptor (TßRIII) is a TGF-ß co-receptor that presents ligand to the type II TGF-ß receptor to initiate signaling. TßRIII also undergoes ectodomain shedding to release a soluble form (sTßRIII) that can bind ligand, sequestering it away from cell surface receptors. We have previously identified a TßRIII extracellular mutant that has enhanced ectodomain shedding ("super shedding (SS)"-TßRIII-SS). Here, we utilize TßRIII-SS to study the balance of cell surface and soluble TßRIII in the context of lung cancer. We demonstrate that expressing TßRIII-SS in lung cancer cell models induces epithelial-to-mesenchymal transition (EMT) and that these TßRIII-SS (EMT) cells are less migratory, invasive and adhesive and more resistant to gemcitabine. Moreover, TßRIII-SS (EMT) cells exhibit decreased tumorigenicity but increased growth rate in vitro and in vivo. These studies suggest that the balance of cell surface and soluble TßRIII may regulate a dichotomous role for TßRIII during cancer progression.


Assuntos
Carcinogênese/metabolismo , Transição Epitelial-Mesenquimal/fisiologia , Proteoglicanas/metabolismo , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Células A549 , Animais , Carcinogênese/patologia , Linhagem Celular , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos/fisiologia , Feminino , Regulação Neoplásica da Expressão Gênica/fisiologia , Células HEK293 , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Nus , Transdução de Sinais/fisiologia
6.
Front Psychiatry ; 5: 70, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25009508

RESUMO

Years-of-school is negatively correlated with illicit drug use. However, educational attainment is positively correlated with IQ and negatively correlated with impulsivity, two traits that are also correlated with drug use. Thus, the negative correlation between education and drug use may reflect the correlates of schooling, not schooling itself. To help disentangle these relations we obtained measures of working memory, simple memory, IQ, disposition (impulsivity and psychiatric status), years-of-school and frequency of illicit and licit drug use in methadone clinic and community drug users. We found strong zero-order correlations between all measures, including IQ, impulsivity, years-of-school, psychiatric symptoms, and drug use. However, multiple regression analyses revealed a different picture. The significant predictors of illicit drug use were gender, involvement in a methadone clinic, and years-of-school. That is, psychiatric symptoms, impulsivity, cognition, and IQ no longer predicted illicit drug use in the multiple regression analyses. Moreover, high risk subjects (low IQ and/or high impulsivity) who spent 14 or more years in school used stimulants and opiates less than did low risk subjects who had spent <14 years in school. Smoking and drinking had a different correlational structure. IQ and years-of-school predicted whether someone ever became a smoker, whereas impulsivity predicted the frequency of drinking bouts, but years-of-school did not. Many subjects reported no use of one or more drugs, resulting in a large number of "zeroes" in the data sets. Cragg's Double-Hurdle regression method proved the best approach for dealing with this problem. To our knowledge, this is the first report to show that years-of-school predicts lower levels of illicit drug use after controlling for IQ and impulsivity. This paper also highlights the advantages of Double-Hurdle regression methods for analyzing the correlates of drug use in community samples.

7.
Mem Inst Oswaldo Cruz ; 108(4): 508-11, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23828001

RESUMO

Trypanosoma cruzi infects humans when infected triatomine vector excreta contaminate breaks in skin or mucosal surfaces. T. cruzi insect-derived metacyclic trypomastigotes (IMT) invade through gastric mucosa after oral challenges without any visible inflammatory changes, while cutaneous and conjunctival infections result in obvious local physical signs. In this study we compared the infectivity of T. cruzi IMT in mice after cutaneous and oral contaminative challenges simulating natural infections. The 50% infective dose (ID50) for oral challenge was 100 fold lower than the ID50 for cutaneous challenge, indicating that oral mucosal transmission is more efficient than cutaneous transmission.


Assuntos
Doença de Chagas/transmissão , Insetos Vetores/parasitologia , Trypanosoma cruzi/patogenicidade , Animais , Doença de Chagas/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Proteínas de Protozoários/fisiologia
8.
Mem. Inst. Oswaldo Cruz ; 108(4): 508-511, jun. 2013. tab
Artigo em Inglês | LILACS | ID: lil-678288

RESUMO

Trypanosoma cruzi infects humans when infected triatomine vector excreta contaminate breaks in skin or mucosal surfaces. T. cruzi insect-derived metacyclic trypomastigotes (IMT) invade through gastric mucosa after oral challenges without any visible inflammatory changes, while cutaneous and conjunctival infections result in obvious local physical signs. In this study we compared the infectivity of T. cruzi IMT in mice after cutaneous and oral contaminative challenges simulating natural infections. The 50% infective dose (ID50) for oral challenge was 100 fold lower than the ID50for cutaneous challenge, indicating that oral mucosal transmission is more efficient than cutaneous transmission.


Assuntos
Animais , Camundongos , Doença de Chagas/transmissão , Insetos Vetores/parasitologia , Trypanosoma cruzi/patogenicidade , Doença de Chagas/parasitologia , Camundongos Endogâmicos BALB C , Proteínas de Protozoários/fisiologia
9.
Mol Biol Cell ; 23(9): 1675-87, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22419816

RESUMO

Myosin-X (Myo10) is an unconventional myosin that localizes to the tips of filopodia and has critical functions in filopodia. Although Myo10 has been studied primarily in nonpolarized, fibroblast-like cells, Myo10 is expressed in vivo in many epithelia-rich tissues, such as kidney. In this study, we investigate the localization and functions of Myo10 in polarized epithelial cells, using Madin-Darby canine kidney II cells as a model system. Calcium-switch experiments demonstrate that, during junction assembly, green fluorescent protein-Myo10 localizes to lateral membrane cell-cell contacts and to filopodia-like structures imaged by total internal reflection fluorescence on the basal surface. Knockdown of Myo10 leads to delayed recruitment of E-cadherin and ZO-1 to junctions, as well as a delay in tight junction barrier formation, as indicated by a delay in the development of peak transepithelial electrical resistance (TER). Although Myo10 knockdown cells eventually mature into monolayers with normal TER, these monolayers do exhibit increased paracellular permeability to fluorescent dextrans. Importantly, knockdown of Myo10 leads to mitotic spindle misorientation, and in three-dimensional culture, Myo10 knockdown cysts exhibit defects in lumen formation. Together these results reveal that Myo10 functions in polarized epithelial cells in junction formation, regulation of paracellular permeability, and epithelial morphogenesis.


Assuntos
Células Epiteliais/citologia , Células Epiteliais/metabolismo , Miosinas/metabolismo , Pseudópodes/metabolismo , Junções Íntimas/metabolismo , Animais , Caderinas/metabolismo , Linhagem Celular , Permeabilidade da Membrana Celular , Polaridade Celular/fisiologia , Cães , Técnicas de Silenciamento de Genes , Rim/citologia , Miosinas/genética , Pseudópodes/química , Proteína da Zônula de Oclusão-1/metabolismo
10.
Curr Biol ; 19(11): 967-73, 2009 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-19398338

RESUMO

Although many proteins, receptors, and viruses are transported rearward along filopodia by retrograde actin flow, it is less clear how molecules move forward in filopodia. Myosin-X (Myo10) is an actin-based motor hypothesized to use its motor activity to move forward along actin filaments to the tips of filopodia. Here we use a sensitive total internal reflection fluorescence (TIRF) microscopy system to directly visualize the movements of GFP-Myo10. This reveals a novel form of motility at or near the single-molecule level in living cells wherein extremely faint particles of Myo10 move in a rapid and directed fashion toward the filopodial tip. These fast forward movements occur at approximately 600 nm/s over distances of up to approximately 10 microm and require Myo10 motor activity and actin filaments. As expected for imaging at the single-molecule level, the faint particles of GFP-Myo10 are diffraction limited, have an intensity range similar to single GFP molecules, and exhibit stepwise bleaching. Faint particles of GFP-Myo5a can also move toward the filopodial tip, but at a slower characteristic velocity of approximately 250 nm/s. Similar movements were not detected with GFP-Myo1a, indicating that not all myosins are capable of intrafilopodial motility. These data indicate the existence of a novel system of long-range transport based on the rapid movement of myosin molecules along filopodial actin filaments.


Assuntos
Movimento Celular/fisiologia , Miosinas/fisiologia , Pseudópodes/fisiologia , Actinas/fisiologia , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Bovinos , Movimento Celular/efeitos dos fármacos , Proteínas de Fluorescência Verde/análise , Células HeLa , Humanos , Microscopia de Fluorescência , Miosinas/análise , Miosinas/ultraestrutura , Pseudópodes/metabolismo , Pseudópodes/ultraestrutura , Tiazolidinas/farmacologia
11.
Artigo em Inglês | MEDLINE | ID: mdl-19185532

RESUMO

A detailed comparison has been made of determinations by (57)Fe Mössbauer spectroscopy and four different XAFS spectroscopic methods of %Fe as hematite and ferrihydrite in 11 iron-based SBA-15 catalyst formulations. The four XAFS methods consisted of least-squares fitting of iron XANES, d(XANES)/dE, and EXAFS (k(3)chi and k(2)chi) spectra to the corresponding standard spectra of hematite and ferrihydrite. The comparison showed that, for this particular application, the EXAFS methods were superior to the XANES methods in reproducing the results of the benchmark Mössbauer method in large part because the EXAFS spectra of the two iron-oxide standards were much less correlated than the corresponding XANES spectra. Furthermore, the EXAFS and Mössbauer results could be made completely consistent by inclusion of a factor of 1.3+/-0.05 for the ratio of the Mössbauer recoilless fraction of hematite relative to that of ferrihydrite at room temperature (293K). This difference in recoilless fraction is attributed to the nanoparticle nature of the ferrihydrite compared to the bulk nature of the hematite. Also discussed are possible alternative non-least-squares XAFS methods for determining the iron speciation in this application as well as criteria for deciding whether or not least-squares XANES methods should be applied for the determination of element speciation in unknown materials.


Assuntos
Compostos Férricos/química , Ferro/química , Análise dos Mínimos Quadrados , Espectroscopia de Mossbauer/métodos , Catálise
13.
J Cell Biol ; 178(7): 1193-206, 2007 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-17893244

RESUMO

The yeast Saccharomyces cerevisiae uses two class V myosins to transport cellular material into the bud: Myo2p moves secretory vesicles and organelles, whereas Myo4p transports mRNA. To understand how Myo2p and Myo4p are adapted to transport physically distinct cargos, we characterize Myo2p and Myo4p in yeast extracts, purify active Myo2p and Myo4p from yeast lysates, and analyze their motility. We find several striking differences between Myo2p and Myo4p. First, Myo2p forms a dimer, whereas Myo4p is a monomer. Second, Myo4p generates higher actin filament velocity at lower motor density. Third, single molecules of Myo2p are weakly processive, whereas individual Myo4p motors are nonprocessive. Finally, Myo4p self-assembles into multi-motor complexes capable of processive motility. We show that the unique motility of Myo4p is not due to its motor domain and that the motor domain of Myo2p can transport ASH1 mRNA in vivo. Our results suggest that the oligomeric state of Myo4p is important for its motility and ability to transport mRNA.


Assuntos
Cadeias Pesadas de Miosina/metabolismo , Miosina Tipo V/metabolismo , Miosinas/metabolismo , Transporte de RNA , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Reagentes de Ligações Cruzadas/farmacologia , Etildimetilaminopropil Carbodi-Imida/farmacologia , Proteínas de Fluorescência Verde/metabolismo , Microscopia Eletrônica , Proteínas Motores Moleculares/metabolismo , Cadeias Pesadas de Miosina/química , Cadeias Pesadas de Miosina/isolamento & purificação , Cadeias Pesadas de Miosina/ultraestrutura , Miosina Tipo V/química , Miosina Tipo V/isolamento & purificação , Miosina Tipo V/ultraestrutura , Miosinas/química , Miosinas/isolamento & purificação , Miosinas/ultraestrutura , Estrutura Quaternária de Proteína , Estrutura Terciária de Proteína , Transporte Proteico/efeitos dos fármacos , Transporte de RNA/efeitos dos fármacos , RNA Mensageiro/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/efeitos dos fármacos , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/isolamento & purificação , Proteínas de Saccharomyces cerevisiae/ultraestrutura
14.
Magn Reson Chem ; 45(5): 393-400, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17394221

RESUMO

This paper presents novel measurements and calculations of the olefinic (13)C chemical shift tensor principal values in several metal diene complexes. The experimental values and the calculations show shifts as large as 70 ppm with respect to the values in the parent olefinic compounds. These shifts are highly anisotropic, with the largest ones observed in the less shielded principal components and the smallest ones in the most shielded principal components of the tensor. The orientations of the principal components of the tensors remain, within 10 degrees , at their directions in ethylene and other olefinic compounds. The calculations, performed using the GIAO method and the LanDZ pseudopotential basis set, show good agreement with the experiments, and were used to establish definite evidence for the existence of a Cl-bridge structure in the bicyclo[2.2.1]hepta-2,5-diene (BCHD)dichlororuthenium(II) polymer.


Assuntos
Alcadienos/química , Espectroscopia de Ressonância Magnética/métodos , Metais Pesados/química , Norbornanos/química , Compostos Organometálicos/química , Anisotropia , Isótopos de Carbono , Ligantes , Molibdênio/química , Paládio/química , Platina/química , Teoria Quântica , Rutênio/química
15.
CNS Spectr ; 11(4): 269-80, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16641833

RESUMO

This article reviews the current state of magnetic resonance imaging techniques as applied to bipolar disorder. Addressed are conventional methods of structural neuroimaging and recently developed techniques. This latter group comprises volumetric analysis, voxel-based morphometry, the assessment of T2 white matter hyperintensities, shape analysis, cortical surface-based analysis, and diffusion tensor imaging. Structural analysis methods used in magnetic resonance imaging develop exponentially, and now present opportunities to identify disease-specific neuroanatomic alterations. Greater acuity and complementarity in measuring these alterations has led to the generation of further hypotheses regarding the pathophysiology of bipolar disorder. Included in the summary of findings is consideration of a resulting neuroanatomic model. Integrative issues and future directions in this relatively young field, including multi-modal approaches enabling us to produce more comprehensive results, are discussed.


Assuntos
Transtorno Bipolar/diagnóstico , Encéfalo/patologia , Aumento da Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Transtorno Bipolar/patologia , Transtorno Bipolar/fisiopatologia , Encéfalo/fisiopatologia , Mapeamento Encefálico , Corpo Estriado/patologia , Corpo Estriado/fisiopatologia , Imagem de Difusão por Ressonância Magnética/métodos , Lobo Frontal/patologia , Lobo Frontal/fisiopatologia , Humanos , Rede Nervosa/patologia , Rede Nervosa/fisiopatologia , Sensibilidade e Especificidade , Lobo Temporal/patologia , Lobo Temporal/fisiopatologia
16.
J Am Coll Health ; 54(1): 15-24, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16050324

RESUMO

The authors studied contributors to stress among undergraduate residence hall students at a midwestern, land grant university using a 76-item survey consisting of personal, health, academic, and environmental questions and 1 qualitative question asking what thing stressed them the most. Of 964 students selected at random, 462 (48%) responded to the survey. The authors weighted data to reflect the overall university-wide undergraduate population (55% men, 12% minority or international, and 25% freshmen). Women and US citizens experienced greater stress than did men and non-US citizens, respectively. Frequency of experiencing chronic illness, depression, anxiety disorder, seasonal affective disorder, mononucleosis, and sleep difficulties were significant stress predictors. Although alcohol use was a positive predictor, drug use was a negative predictor of stress. Both a conflict and a satisfactory relationship with a roommate, as well as a conflict with a faculty or staff member, were also significant predictors of stress.


Assuntos
Características de Residência , Estresse Psicológico/etiologia , Estudantes/psicologia , Universidades , Etnicidade , Feminino , Comportamentos Relacionados com a Saúde , Humanos , Masculino , Saúde Mental , Fatores de Risco
17.
Chem Commun (Camb) ; (11): 1462-4, 2005 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-15756336

RESUMO

The silylation of SBA-15 enhances the reducibility of cobalt oxides on a SBA-15 supported cobalt catalyst, and consequently increases the catalytic activity for Fischer-Tropsch synthesis of hydrocarbons from syngas and selectivity for longer chain products.

18.
J Cell Biol ; 163(6): 1255-66, 2003 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-14691136

RESUMO

Myo4p is a nonessential type V myosin required for the bud tip localization of ASH1 and IST2 mRNA. These mRNAs associate with Myo4p via the She2p and She3p proteins. She3p is an adaptor protein that links Myo4p to its cargo. She2p binds to ASH1 and IST2 mRNA, while She3p binds to both She2p and Myo4p. Here we show that Myo4p and She3p, but not She2p, are required for the inheritance of cortical ER in the budding yeast Saccharomyces cerevisiae. Consistent with this observation, we find that cortical ER inheritance is independent of mRNA transport. Cortical ER is a dynamic network that forms cytoplasmic tubular connections to the nuclear envelope. ER tubules failed to grow when actin polymerization was blocked with the drug latrunculin A (Lat-A). Additionally, a reduction in the number of cytoplasmic ER tubules was observed in Lat-A-treated and myo4Delta cells. Our results suggest that Myo4p and She3p facilitate the growth and orientation of ER tubules.


Assuntos
Retículo Endoplasmático/metabolismo , Cadeias Pesadas de Miosina/metabolismo , Miosina Tipo V/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Citoesqueleto de Actina/efeitos dos fármacos , Citoesqueleto de Actina/metabolismo , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Divisão Celular/fisiologia , Corrente Citoplasmática/fisiologia , Retículo Endoplasmático/ultraestrutura , Membranas Intracelulares/metabolismo , Membranas Intracelulares/ultraestrutura , Mutação/genética , Cadeias Pesadas de Miosina/genética , Miosina Tipo V/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Saccharomyces cerevisiae/ultraestrutura , Proteínas de Saccharomyces cerevisiae/genética , Tiazóis/farmacologia , Tiazolidinas
19.
J Org Chem ; 68(9): 3367-79, 2003 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-12713334

RESUMO

Chemical reduction of 2,4,6-tricyano-1,3,5-triazine, TCT, results in the formation of an unstable radical anion that undergoes immediate dimerization at a ring carbon to form [C(12)N(12)](2-), [TCT](2)(2-), characterized by a long 1.570 (4) A central C[bond]C. [TCT](2)(2-) can decompose into the radical anion of 4,4',6,6'-tetracyano-2,2'-bitriazine, [TCBT]*-, the one-electron reduced form of planar (D(2h)) TCBT, which is also structurally characterized as the [TMPD][TCBT] charge-transfer complex (TMPD = N,N,N',N'-tetramethyl-p-phenylenediamine) with a 1.492 (2) A central sp(2)[bond]sp(2) C[bond]C. Although crystals could not be obtained for the radical anion [TCBT]*-, the electrochemistry (E degrees = +0.03 V), EPR (g = 2.003, (2)A((14)N) = 3.347 G, and (4)A((14)N) = 0.765 G and a line width of 0.24 G), and theoretical calculations support the formation of [TCBT]*-. In addition, thermolysis of [TCT](2)(2-) yields [TCBT]*-. Chemical reduction of 2,4,6-tricyanobenzene, TCB, forms an unstable radical anion that immediately undergoes dimerization at a ring carbon to form [C(12)H(6)N(6)](2-), [TCB](2)(2-), which has a long 1.560 (5) A central C[bond]C. Reaction of TCT with tetrathiafulvalene (TTF) forms structurally characterized [TTF][TCT], and in the presence of water, TCT hydrolyzes to 2,4-dicyano-6-hydroxy-s-triazine, DCTOH. In contrast, the reaction of TCT with TMPD forms [TMPD][TCT], which in the presence of water forms structurally characterized [HTMPD](+)[DCTO](-).

20.
Drug Alcohol Depend ; 67(2): 193-203, 2002 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-12095669

RESUMO

This experiment tested the hypothesis that differences in drug use are correlated with differences in decision making. The subjects were 22 drug clinic patients who had used either opiates or stimulants for an average of 10 years, and 21 community residents who reported that they had rarely used illicit addictive drugs. The procedure consisted of a series of binary choices with two consequences; they earned money and determined the intervals that separated choice trials. Each choice earned the same amount of money, but one initiated a shorter delay to the next trial, whereas the other initiated a shorter delay as averaged over the next two trials. Shorter delays were advantageous in that they increased the overall rate of earnings and they reduced the time spent waiting for the next trial. Thus, one choice was better from the perspective of the current trial, while the other choice was better from the perspective of two or more consecutive trials. Drug-clinic patients were more likely to favor the one-trial solution compared with control subjects, who were more likely to favor the two-trial solution. There were five different choice games, with different versions varying in the magnitude of the advantage for switching from the two-trial to the one-trial solution. Drug clinic and control subjects differed most in the games in which the immediate advantage of the one-trial solution was larger, and all subjects were more likely to choose the global solution when the incentive for switching to the one-trial solution was lower. The results support the view that individual differences in decision making influence the course of illicit drug use.


Assuntos
Comportamento Aditivo/psicologia , Comportamento de Escolha , Transtornos Relacionados ao Uso de Substâncias/psicologia , Adulto , Idoso , Análise de Variância , Comportamento Aditivo/epidemiologia , Comportamento de Escolha/fisiologia , Tomada de Decisões/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos Relacionados ao Uso de Substâncias/epidemiologia
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