Sucrose detection and discrimination estimated by the analysis of psychometric functions with linear and non-linear models.

Sucrose detection and discrimination thresholds were determined by conducting two alternative forced-choice tests with aqueous solutions. The standard models probit and logit, and non-linear were fitted to the empirical psychometric functions. 0, 7 and 15 g/L sucrose solutions were used as standard stimuli in the detection and discrimination experiments (two levels) respectively. Comparison stimuli consisted of aqueous sucrose solutions with concentrations from 0.5 to 25 g/L. Observed absolute threshold was around 2.96 g/L and the difference limen for 7 and 15 g/L standard stimuli was around 2.98 g/L and 5.29 g/L, respectively. Calculated Weber fractions for 7 and 15 g/L standard stimuli were 0.42 and 0.35, respectively. Judges' performance in the discrimination experiment was similar to that observed in the detection experiment. Goodness of fit for probit and logit models was similar. The non-linear model showed a lower average error and demonstrated an excellent predictive ability.

Angiotensin receptor type 1 single nucleotide polymorphism 1166A/C is associated with malignant arrhythmias and altered circulating miR-155 levels in patients with chronic heart failure.

BACKGROUND: Sudden cardiac death (SCD) from ventricular tachyarrhythmias accounts for approximately 450,000 annual deaths in the United States; many of these cases involve patients with chronic heart failure (HF). Prediction of which HF patients are most susceptible to SCD is difficult, and it is uncertain whether gene polymorphisms associated with HF outcomes are also linked to arrhythmic risk. METHODS: We evaluated 485 patients with chronic HF to see whether the angiotensin receptor type 1 (AT1R) 1166A/C or angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphisms were associated with a higher rate of ventricular arrhythmias requiring implantable cardioverter defibrillator (ICD) therapies over a 5-year period. We assessed the correlation between polymorphisms and antitachycardia pacing (ATP) and/or ICD shocks. RESULTS: Patients with AT1R-1166CC genotype had an increased rate of all events: ATP plus ICD shocks (P = .02). There was no association between ACE I/D genotype and ICD therapies. Furthermore, circulating levels of microRNA-155 (miR-155), a microRNA known to posttranscriptionally regulate AT1R expression, were significantly decreased in the CC compared with the AC and AA genotypes and were associated with ICD events. CONCLUSION: Our study suggests that the AT1R-1166CC genotype is associated with increased ICD therapies in patients with chronic HF, and the level of circulating miR-155 may be a potential marker for arrhythmic risk. Although these findings are novel, they will need replication and validation in larger cohorts of chronic HF patients.

Mitochondrial reactive oxygen species and calcium uptake regulate activation of phagocytic NADPH oxidase.

Production of superoxide (O(2)(·-)) by NADPH oxidases contributes to the development of hypertension and atherosclerosis. Factors responsible for activation of NADPH oxidases are not well understood; interestingly, cardiovascular disease is associated with both altered NADPH oxidase activity and age-associated mitochondrial dysfunction. We hypothesized that mitochondrial dysfunction may contribute to activation of NADPH oxidase. The effect of mitochondrial inhibitors on phagocytic NADPH oxidase in human lymphoblasts and whole blood was measured at the basal state and upon PKC-dependent stimulation with PMA using extracellular 1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl-trimethylammonium or mitochondria-targeted 1-hydroxy-4-[2-triphenylphosphonio)-acetamido]-2,2,6,6-tetramethylpiperidine spin probes and electron spin resonance (ESR). Intracellular cytosolic calcium [Ca(2+)](i) was measured spectrofluorometrically using fura-2 AM. Incubation of lymphoblasts with the mitochondrial inhibitors rotenone, antimycin A, CCCP, or ruthenium red (an inhibitor of mitochondrial Ca(2+) uniporter) did not significantly change basal activity of NADPH oxidase. In contrast, preincubation with the mitochondrial inhibitors prior to PMA stimulation of lymphoblasts resulted in two- to three-fold increase of NADPH oxidase activity compared with stimulation with PMA alone. Most notably, the intracellular Ca(2+)-chelating agent BAPTA-AM abolished the effect of mitochondrial inhibitors on NADPH oxidase activity. Cytosolic Ca(2+) measurements with fura-2 AM showed that the mitochondrial inhibitors increased [Ca(2+)](i), while BAPTA-AM abolished the increase in [Ca(2+)](i). Furthermore, depletion of cellular Ca(2+) with thapsigargin attenuated CCCP- and antimycin A-mediated activation of NADPH oxidase in the presence of PMA by 42% and 31%, correspondingly. Our data suggest that mitochondria regulate PKC-dependent activation of phagocytic NADPH oxidase. In summary, increased mitochondrial O(2)(·-) and impaired buffering of cytosolic Ca(2+) by dysfunctional mitochondria result in enhanced NADPH oxidase activity, which may contribute to the development of cardiovascular diseases.

Organic n-channel field-effect transistors based on arylenediimide-thiophene derivatives.

The synthesis, structural, electrochemical, and thin film electrical and electronic structural properties of a series of arylene diimide-oligothiophene n-type semiconductors are reported. This family of compounds allows analysis of the effects on thin film transistor performance of the following: (i) oligothiophene backbone catenation; (ii) naphthalenediimide vs perylenediimide core interchange; (iii) phenylene group introduction in the oligothiophene backbone. Electrochemical experiments indicate similar redox energetics for all members of this series, while thin film transistor measurements reveal markedly different charge transport performances. The highest electron mobility of 0.35 cm(2) V(-1) s(-1) is recorded for films of benzo[lmn]thieno[3',4':4,5]imidazo[2,1-b][3,8]phenanthroline-1,3,6(2H)-trione, 2-octyl (NDI-1T). Solution-processed field effect transistors were also fabricated and surprisingly exhibit electrical performances surpassing that of the vapor-deposited films in the case of isoquino[6',5',4':10,5,6]anthra[2,1,9-def]thieno[3',4':4,5]imidazo[2,1-a]isoquinoline-1,3,8(2H)-trione, 2-(1-heptyloctyl)-10,12-di-2-thienyl (PDI-3T).

A beta-naphthaleneimide-modified terthiophene exhibiting charge transfer and polarization through the short molecular axis. Joint spectroscopic and theoretical study.

We present a new terthiophene derivative substituted at the thienyl beta positions with a naphthalenediimide functionalization. The UV-vis absorption and emission spectroscopic properties as well as the electrochemical properties have been discussed to describe its electronic structure. The vibrational Raman data are used to inspect the molecular architecture. All of the experimental data are supported by quantum chemical calculations with different approaches. A close comparison with other terthiophenes available in the literature is conducted, always stressing the effect of the relative orientation of the donor and acceptor groups either with long-axis or short-axis polarizations. The electronic structure of the molecule has been understood in terms of the HOMO-LUMO absolute energy values. A considerable reduction of the band gap from the constituting units to the studied molecule is detected, although electronic interaction is not optimal for this configuration. Fluorescence quenching is interpreted by the possibility of intersystem crossing and internal conversion. Finally, Raman spectroscopy gives additional information of the distribution of conjugation along the molecular domain, of subtle conformational effects, and of the intermolecular interaction by means of temperature-dependent Raman data. This study provides guidelines for controlling the electronic structure and for exploring new strategies pursuing improved dyes.

Click-functionalization of conducting poly(3,4-ethylenedioxythiophene) (PEDOT).

Efficient post-functionalization of conductive polymer films was achieved by Cu(+)-catalyzed "click"-cycloaddition of novel poly(azidomethyl-EDOT) and various functionalized terminal alkynes under mild heterogeneous conditions with high conversion efficiencies.

Synthesis and photophysical properties of conjugated polymers with pendant 9,10-anthraquinone units.

We have synthesized and investigated the photophysical properties of a series of electron-donor conjugated copolymers with pendant electron-acceptor units. The copolymers consist of diethynyl-1,4-phenylene, fluorene, or phenylene rings alternating with a phenylene unit bearing a pendant 9,10-anthraquinone moiety. The pendant donor-acceptor polymers were designed to have different optical pi-pi* band gaps, while the oxidation potential of the polymer backbone remains approximately constant in the series. The reduction potential of the donor-acceptor polymers is associated with the pendant acceptor units. This leads to the special situation that the electrochemical gap between oxidation and reduction potentials is constant, while the optical band gap decreases, going from PPP, via PPF, to PPE. This design is used to study the effect of the optical gap on the photoinduced electron-transfer reaction that occurs between the main chain electron donor and the pendant acceptor, while the same polymer architecture and energy of the charge separated state are maintained. Fluorescence and photoinduced absorption spectroscopy are used to study the electron transfer following photoexcitation in relation to solvent polarity and in thin solid films. For the fluorene-phenylene alternating copolymer, intramolecular photoinduced electron transfer occurs in the Marcus optimal region.

An ambipolar peryleneamidine monoimide-fused polythiophene with narrow band gap.

A peryleneamidine monoimide-fused terthiophene with a band gap of 1.4 eV has been synthesized. The donor-acceptor system can be electropolymerized to generate a functionalized polythiophene with a band gap of 0.9 eV and with ambipolar characteristics showing high electroactivity in both the p- and the n-doping process. This is the first example of a p-type conjugated polymer in direct conjugation with n-type perylenemonoimide moieties.

Technical note: medial approach for proximal tibia bone graft using a manual trephine.

OBJECTIVE: The purpose of this review is to assess the use of a manual trephine for harvesting bone grafts from the medial aspect of proximal tibia. STUDY DESIGN: The medial approach for proximal tibia is described with detailed landmarks and anatomic relationships, pointing out the advantages of using a manual trephine. A retrospective review of 33 patients who underwent this technique in a 3-year period is reported. RESULTS: The medial aspect of proximal tibia was found to supply the requirements of cancellous bone graft for all the osseous defects, with the exception of bilateral sinus lifts. There were no major complications at the donor site; only 2 cases of local infection and unaesthetic scar were found, respectively. Morbidity at the receptor site was attributable to the lack of soft tissue coverage. CONCLUSION: Medial approach for proximal tibia with a manual trephine seems to be a valuable tool to harvest autogenous cancellous bone grafts with simplicity, safety, and predictability.

Frontal sinus mucocele with intracranial and intraorbital extension.

INTRODUCTION: Frontal sinus mucoceles can present with a multitude of different symptoms including ophthalmic disturbances. Even benign, they have a tendency to expand by eroding the surrounding bony walls that displaces and destroys structures by pressure and bony resorption. CASE REPORT: A 32-year-old man with diplopia, proptosis of the right eye and headache was presented. The diagnosis was frontal sinus mucocele with intracranial and intraorbital extension. Possible clinical manifestations of mucoceles, diagnostic imaging techniques and treatment used are discussed. CONCLUSION: Frontal mucoceles are benign and curable, early recognition and management of them is of paramount importance, because they can cause local, orbital or intracranial complications.

Frontal sinus mucocele with intracranial and intraorbital extension

No disponibleIntroducción: Los mucoceles del seno frontal pueden presentarse con multitud de síntomas diferentes, incluyendo alteracionesoftálmicas. Son benignos, aunque tienen tendencia a la expansión mediante erosión de las paredes adyacentes, lo que produce desplazamiento y destrucción de estructuras por presión y resorción ósea. Caso clínico: Se presenta el caso de un hombre de 32 años con diplopia, proptosis del ojo derecho y cefalea fronto-temporal, cuyo diagnóstico fue de mucocele del seno frontal con extensión intracraneal e intraorbitaria. Discutiremos las posibles manifestaciones clínicasde los mucoceles, las técnicas de imagen empleadas, así como el tratamiento realizado. Conclusión: Los mucoceles del seno frontal son benignos y curables, aunque un rápido diagnóstico y tratamiento son de vital importancia ya que pueden causar complicaciones locales, orbitarias o intracraneales

Introduction: Frontal sinus mucoceles can present with a multitude of different symptoms including ophthalmic disturbances.Even benign, they have a tendency to expand by eroding the surrounding bony walls that displaces and destroys structures by pressure and bony resorption. Case report: A 32-year-old man with diplopia, proptosis of the right eye and headache was presented. The diagnosis was frontal sinus mucocele with intracranial and intraorbital extension. Possibleclinical manifestations of mucoceles, diagnostic imaging techniques and treatment used are discussed. Conclusion: Frontal mucoceles are benign and curable, early recognition and management of them is of paramount importance, because they can cause local, orbital or intracranial complications

Lack of evidence for in vivo transformation of zidovudine triphosphate to stavudine triphosphate in human immunodeficiency virus-infected patients.

The in vivo and in vitro determination of significant intracellular stavudine (d4T) triphosphate (d4TTP) concentrations in human immunodeficiency virus (HIV)-infected subjects and NS-1 cells treated with zidovudine (ZDV) has recently been reported. This study was conducted to corroborate these findings with in vivo samples from HIV-infected subjects taking ZDV and in vitro CEM(SS) cells incubated with different ZDV concentrations. Previously, we have reported on our validated high-performance liquid chromatography coupled with tandem mass spectrometry methodology for the simultaneous determination of d4TTP, lamivudine triphosphate, and ZDV triphosphate (ZDVTP) concentrations. Using this methodology, we monitored the d4TTP concentration in more than 100 samples from HIV-infected subjects treated with d4T. In addition, we simultaneously monitored the concentrations of d4TTP and ZDVTP in more than 500 samples from HIV-infected individuals who were taking ZDV. Finally, we performed in vitro studies by incubating CEM(SS) cells with 10 microM, 50 microM, and 100 microM ZDV and monitored the formation of d4TTP at 24 and 48 h. We could measure d4TTP concentrations from HIV-infected individuals with a limit of quantitation (LOQ) of 2.7 fmol/10(6) cells (total injection, 54 fmol). In the in vivo studies, we measured the d4TTP concentrations among patients receiving d4T treatment, but the samples from patients taking ZDV did not provide d4TTP concentrations above the LOQ. Furthermore, in vitro samples did not produce any signal for d4TTP, despite the detection of substantial ZDVTP concentrations in CEM(SS) cells. Thus, contrary to the previous report, we found no evidence for the in vivo or in vitro transformation of ZDVTP to d4TTP in HIV-infected subjects or CEM(SS) cells.

Prediction of atrial fibrillation following cardiac surgery using rough set derived rules.

Atrial fibrillation (AF) and flutter are common following cardiac surgery, increasing costs and morbidity. Cardiologists need a method to discern those patients who are at high risk for this arrhythmia in order to attempt to treat them by either pharmacologic or non-pharmacologic means. We performed a retrospective analysis of 377 CABG patients, of which 94 developed AF post-operatively. Feature selection and AF occurrence prediction was performed using a multivariate regression model, and two rough set derived rule classifiers. The rough set derived feature subset performed best with an accuracy of 87%, a sensitivity of 58.5%, and a specificity of 96.5%. This shows the importance of testing feature subsets, thereby discouraging the practice of simply combining the best individual predictors. The utility of rough set theory in prediction of cardiac arrhythmia is also validated.