Sintonização de estados quânticos: um estudo numérico do oscilador harmônico quântico

The quantum harmonic oscillator is described by the Hermite equation.¹ The asymptotic solution is predominantly used to obtain its analytical solutions. Wave functions (solutions) are quadratically integrable if taken as the product of the convergent asymptotic solution (Gaussian function) and Hermite polynomial,¹ whose degree provides the associated quantum number. Solving it numerically, quantization is observed when a control real variable is "tuned" to integer values. This can be interpreted by graphical reading of Y(x) and |Y(x)|², without other mathematical analysis, and prove useful for teaching fundamentals of quantum chemistry to undergraduates.

Effect of age on upper and lower eyelid saccades

To study the effect of age on the metrics of upper and lower eyelid saccades, eyelid movement of two groups of 30 subjects each were measured using computed image analysis. The patients were divided on the basis of age into a younger group (20-30 years) and an older group (60-91 years). Eyelid saccade functions were fitted by the damped harmonic oscillator model. Amplitude and peak velocity were used to compare the effect of age on the saccades of the upper and lower eyelid. There was no statistically significant difference in saccade amplitude between groups for the upper eyelid (mean ± SEM; upward, young = 9.18 ± 0.32 mm, older = 8.93 ± 0.31 mm, t = 0.56, P = 0.58; downward, young = 9.11 ± 0.27 mm, older = 8.86 ± 0.32 mm, t = 0.58, P = 0.56) However, there was a clear decline in the peak velocity of the upper eyelid saccades of older subjects (upward, young = 59.06 ± 2.34 mm/s, older = 50.12 ± 1.95 mm/s, t = 2.93, P = 0.005; downward, young = 71.78 ± 1.78 mm/s, older = 60.29 ± 2.62 mm/s, t = 3.63, P = 0.0006). In contrast, for the lower eyelid there was a clear increase of saccade amplitude in the elderly group (upward, young = 2.27 ± 0.09 mm, older = 2.98 ± 0.15 mm, t = 4.33, P < 0.0001; downward, young = 2.21 ± 0.10 mm, older = 2.96 ± 0.17 mm, t = 3.85, P < 0.001). These data suggest that the aging process affects the metrics of the lid saccades in a different manner according to the eyelid. In the upper eyelid the lower tension exerted by a weak aponeurosis is reflected only on the peak velocity of the saccades. In the lower eyelid, age is accompanied by an increase in saccade amplitude which indicates that the force transmission to the lid is not affected in the elderly.

The indeterminate form of human chronic Chagas' disease: a clinical epidemological review

Data on the epidemiology and the natural history of the indeterminate form of human chronic Chagas' disease (IFCCD) are discussed, revealing its great importance in endemic areas of Brazil. The work shows that IFCCD presents a gradual and very slow course, causing a benign picture in the studied patients. Evolution patterns, prognostic and anatomopathological features are also discussed. For practical purposes, the classical concept of IFCCD proved to be simple, operational and consistent, It is defined by the absence of symptoms and clinical findings in chronic infected patients with positive serology and/or parasitological examinations for Trypanosoma cruzi coupled with normal electrocardiographic and radiological exams (heart, oesophagus and colon X-Rays). If a patient is submitted to more rigorous and sophisticated tests, these can reveal some alterations, generally small ones and unable to interfere with the prognosis of the infection. It is suggested that research lines specially related to the evolution ary factors and immunological involvement during this phase be adopted.

Laboratory diagnosis of Schistosomiasis in areas of low transmission: a review of a line of research

After 57 years of successful control of schistosomiasis in Venezuela, the prevalence and intensity of infection have declined. Approximately 80% of the individuals eliminate less than 100 eggs/g of stools, therefore morbidity is mild and the majority are asymptomatic. The sensitivity of Kato-Katz decreases to approximately 60%. Available serological methods for the detection of circulating antigens only reach a 70% of sensitivity. Tests based on the detection of antibodies by immunoenzymatic assays have been improved. The circumoval precipitine test has shown a high sensitivity (97%), specificity (100%), and correlation with oviposition, being considered the best confirmatory diagnostic test. Additionally to the classical immunoenzymatic assays, the development of the alkaline phosphatase immunoassay, allowed to reach a 100% specificity with an 89% sensitivity. Recently, we have developed a modified ELISA in which the soluble egg antigen is treated with sodium metaperiodate (SMP-ELISA) in order to eliminate the glycosilated epitopes responsible for the false positive reactions. The specificity and sensitivity reaches 97% and 99%, respectively. Synthetic peptides from the excretory-secretory enzymes, cathepsin B (Sm31) legumain (Sm32) and cathepsin D (Sm45), have been synthesized. The combination of two peptides derived from the Sm31 have been evaluated, reaching a sensitivity of 96% when analyzed independently and with a 100% specificity. Antibodies raised in rabbits against peptides derived from the Sm31 and Sm32 are currently evaluated in two different antigen-capture-based assays. The development of a simple, cheap and reliable test that correlates with parasite activity is a major goal.

Group A rotavirus genotypes and the ongoing Brazilian experience: a review

Brazil was the first Latin American country to introduce universal group A rotavirus (RV-A) vaccination in March 2006, resulting in a unique epidemiological scenario. Since RV-A first identification in Brazil, 2,691 RV-A-positive stool samples, collected between 1982- 2007, were typed by independent research groups throughout the country. In the pre-vaccination era, 2,492 RV-A-positive samples collected from 1982-2005 were successfully typed, while 199 samples were analyzed from 2006-2007. According to the reviewed studies, there were two important times in the pre-vaccination era: (i) the period from 1982-1995, during which the detection of G5P[8] RV-A, in addition to the classical genotypes G1-4, challenged vaccine development programs; and (ii) the period from 1996-2005, during which genotype G9P[8] emerged, following a global trend. The rate of G2P[4] RV-A detection decreased from 26% (173/653) during 1982-1995 to 2% (43/1,839) during 1996-2005. The overall detection rate of RV-A genotypes from 1982-2005 was as follows: 43% (n = 1,079) G1P[8]/G1P[not typed (NT)]; 20% (n = 488) G9P[8]/G9P[NT]; 9% (n = 216) G2P[4]/G2P[NT]; 6% (n = 151) G3P[8]/G3P[NT]; 4% (n = 103) G4P[8]/G4P[NT]; and 4% (n = 94) G5P[8]/G5P[NT]. Mixed infections accounted for 189 (7%) of the positive samples, while atypical G/P combinations or other genotypes, including G6, G8, G10 and G12, were identified in 172 (7%) samples. The initial surveillance studies carried out in several Brazilian states with RV-A-positive samples collected in 2006 and 2007 show a predominance of G2P[4] strains (148/199 or 74%). Herein, we review RV-A typing studies carried out since the 1980s in Brazil, highlighting the dynamics of RV-A strain circulation profiles before and early after universal use of RV-A vaccine in Brazil.

Studying nanotoxic effects of CdTe quantum dots in Trypanosoma cruzi

Semiconductor nanoparticles, such as quantum dots (QDs), were used to carry out experiments in vivo and ex vivo with Trypanosoma cruzi. However, questions have been raised regarding the nanotoxicity of QDs in living cells, microorganisms, tissues and whole animals. The objective of this paper was to conduct a QD nanotoxicity study on living T. cruzi protozoa using analytical methods. This was accomplished using in vitro experiments to test the interference of the QDs on parasite development, morphology and viability. Our results show that after 72 h, a 200 μM cadmium telluride (CdTe) QD solution induced important morphological alterations in T. cruzi, such as DNA damage, plasma membrane blebbing and mitochondrial swelling. Flow cytometry assays showed no damage to the plasma membrane when incubated with 200 μM CdTe QDs for up to 72 h (propidium iodide cells), giving no evidence of classical necrosis. Parasites incubated with 2 μM CdTe QDs still proliferated after seven days. In summary, a low concentration of CdTe QDs (2 μM) is optimal for bioimaging, whereas a high concentration (200 μM CdTe) could be toxic to cells. Taken together, our data indicate that 2 μM QD can be used for the successful long-term study of the parasite-vector interaction in real time.

Operador dipolo-dipolo na base de momento angular: um complemento ao estudo de ressonância magnética nuclear

The relationship between the magnetic dipole-dipole potential energy function and its quantum analogue is presented in this work. It is assumed the reader is familiar with the classical expression of the dipolar interaction and has basic knowledge of the quantum mechanics of angular momentum. Except for these two points only elementary steps are involved.

Comparison of Classical and Secondary Cytologic Criteria Relative to Hybrid Capture for Diagnosing Cervical-vaginal Infection by Human Papillomavirus

Objective To compare the diagnostic accuracy of the classic Meisels cytologic criteria and the Schneider secondary criteria relative to the hybrid capture method for diagnosing HPV infection. Methods This was a retrospective study performed at a public university hospital. A total of 41 patients with a cytologic diagnosis of HPV infection and 40 HPV-negative patients were selected for review of the cervical-vaginal smears seeking to classical and secondary criteria. A single pathologist reviewed the slides in search of the criteria. The classical and secondary cytologic criteria were compared with the hybrid capture for diagnosing HPV infection. Bartleti test was applied for the age analysis, and Fisher's exact test was used to compare proportions. The tests were considered significant when the probability of rejecting the null hypothesis was less than 5% (p < 0.05). Results The Meisels criteria were less sensitive (34.0%) than the secondary Schneider criteria (57.5%) when compared with the hybrid capture (p < 0.0001), although the specificity of the former criteria was non-significantly higher (91.2% and 67.7%, respectively). In cases of moderate or intense inflammation, the sensitivity and specificity of the Schneider criteria were decreased, 33.3% and 50.0% respectively (p = 0.0115). Conclusions Compared with hybrid capture for diagnosis of HPV infection, the sensitivity of the secondary Schneider criteria was higher than the classical Meisels criteria.Moderate or intense inflammation reduces the sensitivity and specificity of the secondary Schneider criteria for diagnosing HPV infection using the hybrid capture as the gold standard.

Electrophysiological measurements of spectral sensitivities: a review

Spectral sensitivities of visual systems are specified as the reciprocals of the intensities of light (quantum fluxes) needed at each wavelength to elicit the same criterion amplitude of responses. This review primarily considers the methods that have been developed for electrophysiological determinations of criterion amplitudes of slow-wave responses from single retinal cells. Traditional flash methods can require tedious dark adaptations and may yield erroneous spectral sensitivity curves which are not seen in such modifications as ramp methods. Linear response methods involve interferometry, while constant response methods involve manual or automatic adjustments of continuous illumination to keep response amplitudes constant during spectral scans. In DC or AC computerized constant response methods, feedback to determine intensities at each wavelength is derived from the response amplitudes themselves. Although all but traditional flash methods have greater or lesser abilities to provide on-line determinations of spectral sensitivities, computerized constant response methods are the most satisfactory due to flexibility, speed and maintenance of a constant adaptation level

Classical and recent advances in the treatment of inflammatory bowel diseases

Crohn's disease (CD) and ulcerative colitis (UC) are intestinal disorders that comprise the inflammatory bowel diseases (IBD). These disorders have a significant effect on the quality of life of affected patients and the increasing number of IBD cases worldwide is a growing concern. Because of the overall burden of IBD and its multifactorial etiology, efforts have been made to improve the medical management of these inflammatory conditions. The classical therapeutic strategies aim to control the exacerbated host immune response with aminosalicylates, antibiotics, corticosteroids, thiopurines, methotrexate and anti-tumor necrosis factor (TNF) biological agents. Although successful in the treatment of several CD or UC conditions, these drugs have limited effectiveness, and variable responses may culminate in unpredictable outcomes. The ideal therapy should reduce inflammation without inducing immunosuppression, and remains a challenge to health care personnel. Recently, a number of additional approaches to IBD therapy, such as new target molecules for biological agents and cellular therapy, have shown promising results. A deeper understanding of IBD pathogenesis and the availability of novel therapies are needed to improve therapeutic success. This review describes the overall key features of therapies currently employed in clinical practice as well as novel and future alternative IBD treatment methods.