Chemical synthesis and optical, structural, and surface characterization of InP-In2O3 quantum dots.

InP-In2O3 colloidal quantum dots (QDs) synthesized by a single-step chemical method without injection of hot precursors (one-pot) were investigated. Specifically, the effect of the tris(trimethylsilyl)phosphine, P(TMS)3, precursor concentration on the QDs properties was studied to effectively control the size and shape of the samples with a minimum size dispersion. The effect of the P(TMS)3 precursor concentration on the optical, structural, chemical surface, and electronic properties of InP-In2O3 QDs is discussed. The absorption spectra of InP-In2O3 colloids, obtained by both UV-Vis spectrophotometry and photoacoustic spectroscopy, showed a red-shift in the high-energy regime as the concentration of the P(TMS)3 increased. In addition, these results were used to determine the band-gap energy of the InP-In2O3 nanoparticles, which changed between 2.0 and 2.9 eV. This was confirmed by Photoluminescence spectroscopy, where a broad-band emission displayed from 2.0 to 2.9 eV is associated with the excitonic transition of the InP and In2O3 QDs. In2O3 and InP QDs with diameters ranging approximately from 8 to 10 nm and 6 to 9 nm were respectively found by HR-TEM. The formation of the InP and In2O3 phases was confirmed by X-ray Photoelectron Spectroscopy.

Photoacoustic characterization of wheat bread mixed with Moringa oleifera.

Photoacoustic spectroscopy is applied to evaluate the impact of Moringa at different concentrations (0, 1.25, 2.5, 5 and 10%) on the elaboration, sanity, texture, and color of wheat bread. It was found that: i) Photoacoustic signal amplitude values of bread significantly increase from 37 to 90% when moringa powder concentration raises from 1.25% to 10%, at 300 nm wavelength. ii) Comparing the photoacoustic signal values at 300, 330, and 370 nm wavelengths, produced by the different bread types, there were statistically significant differences. iii) The sanitary quality of bread mixed with a 2.5% of moringa is relatively higher than the ones obtained for other concentrations, such that the number of fungal colonies were reduced by 99% in comparison with the control bread without moringa, after six days of storage. Moringa at 2.5% of concentration could thus improve the sanitary quality of wheat bread. iv) The addition of moringa for making bread slows down its textural changes (hardness, elasticity, cohesiveness, resilience, and chewiness) during storage. v) Finally, the highest correlation between the photoacoustic amplitude and the moringa concentration occurs at the wavelengths of 300 and 330 nm, which could be related to significant changes in the content of flavonoids and phenolic acids.

Photothermal techniques applied to the determination of the water vapor diffusion coefficient and thermal diffusivity of edible films.

Water vapor diffusion coefficient (WVDC) and thermal diffusivity (alpha) were determined in gelatin-starch films through photothermal techniques. The effect of different variables in the elaboration of these films, such as starch and glycerol concentrations and pH, were evaluated through the response surface methodology. The results indicated that an increase in the glycerol concentration and pH favored the WVDC of the films. On the other hand, alpha was influenced principally by the starch content and pH of the film-forming solution. The minimum alpha value was 4.5 x 10(-4) cm2/s, which is compared with alpha values reported for commercial synthetic polymers.

Thermal diffusivity of nanofluids containing Au/Pd bimetallic nanoparticles of different compositions.

Colloidal suspensions of bimetallic Au/Pd nanoparticles were prepared by simultaneous reduction of the metal ions from their corresponding chloride salts with polymer (PVP) stabilizer. Thermal properties of water containing bimetallic nanoparticles with different nominal compositions (Au/Pd = 12/1, 5/1, 1/1, 1/5) were measured using the mode mismatched dual-beam thermal lens technique to determine the effect of particle composition on the thermal diffusivity of the nanofluids. The characteristic time constant of the transient thermal lens was estimated by fitting the experimental data to the theoretical expression for transient thermal lens. The thermal diffusivity of the nanofluids (water, containing Au/Pd bimetallic nanoparticles) is seen to be strongly dependent on the composition of the particles. The maximum diffusivity was achieved for the nanoparticles with highest Au/Pd molar ratio. A possible mechanism for such high thermal diffusivity of the nanofluids with bimetallic particles is given. UV-Vis spectroscopy, TEM and high-resolution electron microscopy (HREM) techniques were used to characterize the Au/Pd bimetallic nanoparticles.

Effective protection against experimental Taenia solium tapeworm infection in hamsters by primo-infection and by vaccination with recombinant or synthetic heterologous antigens.

The disease caused by Taenia solium is progressively being recognized as a growing global threat for public human health and pig husbandry that requires the development of effective control measures. A central participant in the taeniasis/cysticercosis transmission network is the human carrier of the adult tapeworm because of its great potential in spreading the infection. Herein, evidence is presented that a primary infection of golden hamsters with orally administered T. solium cysticerci improved the host's resistance against a secondary infection. Likewise, previous vaccination increased the hamster's resistance. Similar high levels of protection (> 78%) were induced by systemic or oral vaccination with the S3Pvac anticysticercosis synthetic peptide vaccine or the highly immunogenic recombinant chimera based on the protective peptide KETc1 bound to Brucella spp. lumazine synthase (BLS-KETc1). Increased resistance after primo-infection and vaccination possibly results from changes in the immune conditions prevailing in the host's intestine. The contribution to protection from the KETc1 and BLS epitopes in a chimeric vaccine is under study. Preventive vaccination of definitive hosts of T. solium against the tapeworm, the most relevant step in the taeniasis/cysticercosis transmission, may greatly impact the dynamics of endemic disease and has not been studied or tried previously.

Interference effects in photoacoustic and reflectance spectroscopies on TiO2/Si structures and TiO2 band gap.

Experimental results of photoacoustic (PAS) and reflectance (RS) spectroscopies of titanium dioxide thin films (TiO2), deposited on Si substrates, are compared in a wide optical range including transparent and absorbent regions of TiO2. Due to the fact that the light modulation frequency f used in the photoacoustic experiments was so low that the thermal diffusion length of the TiO2 (mu = 100 microm) is always larger than the thickness of the studied films, the PAS turns out to be complementary to RS over the entire range. The presence of multiple reflection interference effects makes difficult a direct evaluation of the TiO2 band gap from the PAS signal. However, by employing k(lambda) values, obtained from transmission experiments on equivalent TiO2 films deposited on transparent fused quartz substrates, the PAS spectra for the films deposited on silicon are reconstructed by using those theoretical models that consider multiple reflections. The reasonable agreement of the simulated and experimental PAS spectra allows one to obtain reliable Eg values for the TiO2 films deposited on opaque silicon substrates.

Multiple recurring paragangliomas: a problem of diagnosis and location. Case report and review of the literature.

RATIONALE: Paragangliomas constitute a particular diagnostic challenge because of the difficulties involved in identifying new lesions. CASE REPORT: The findings in the case of a young woman with multiple recurring paragangliomas which reappeared eleven years after successful surgical treatment are presented. DISCUSSION: This case illustrates the diagnostic difficulties of this pathologic entity and the lack of a technique of sufficient sensitivity to reveal the existence of one or more tumors with or without hormonal secretion, their location and rate of growth and the number of neoplasias to avoid as many surgical interventions as possible. Inasmuch as an ideal technique for diagnosis and localization of this type of tumor remains to be developed, non-invasive methods, particularly 131I MIBG scintigraphy, play a significant role in evaluation because of their high sensitivity for detecting chromaffin tissue, especially in extra-adrenal locations. CONCLUSION: Periodic long-term radionuclide scanning should be recommended for all asymptomatic patients given the risk of residual and/or reactivating tumoral tissue with benign or metastatic behavior.

[Carcinoid syndrome: report of a case with heart involvement and primary ovarian tumor]. / Síndrome carcinoide: reporte de un caso con afección cardiaco y tumor primario de ovario.

A patient with a primary ovarian carcinoid tumor with extensive carcinoid heart disease, without hepatic metastases is presents. Literature was revisited, emphasizing that carcinoid heart disease secondary to an ovarian tumor is quite rare. Surgical indications relative to this patient are discussed.

Caracterización óptica del Sistema Nervioso Central de Haementeria officinalis / Optical characterization of the Central Nervous System of Haementeria officinalis

Resumen: La falla en la regeneración de las neuronas del sistema nervioso central (SNC) en vertebrados superiores es un problema que no se ha resuelto completamente, esto limita la rehabilitación de muchas conductas motoras después de una lesión en la médula espinal. En la regeneración neuronal intervienen múltiples factores y de estos, los que inducen el crecimiento neurítico se han estudiado para intentar favorecer la extensión y la reconexión de las neuronas lesionadas con sus blancos. La regeneración del SNC de sanguijuelas se ha estudiado intensamente porque permite abordar el problema a diferentes niveles con distintas técnicas, en este trabajo se obtuvo el espectro de absorción óptico, con espectroscopía fotoacústica (EFA), del SNC y de tejido de la sanguijuela Haementeria officinalis, con el objetivo de conocer las longitudes de onda óptimas para la irradiación posterior de células del SNC y de tejido H. officinalis. Los resultados de este estudio muestran que el SNC de estos organismos absorbe en la region comprendida de 300 nm a 500 nm, y las muestras de tejido tienen un máximo de absorción óptico proximo a 300 nm, además se observaron diferencias evidentes entre los espectros de absorción ópticos del SNC con lesión y el control (sin lesión).

Abstract: The failure in the neuron regeneration in the central nervous system (CNS) in higher vertebrates, is a not completely solved problem, this limits the rehabilitation of many motor conducts after an injury in the spinal cord. In neuronal regeneration multiple factors are involved, between them those that induce the neurite outgrowth which has been studied to try to encourage the extension and reconnection of the injury neurons with their blanks. The regeneration of the CNS of leeches has been intensely studied because allows to approach the problem at different levels with different techniques. In this study the optical absorption spectrum of the CNS and the tissue of the leech H. officinalis was obtained, by using photoacoustic spectroscopy (PAS), in order to investigate the optimal wavelenghts for later irradiation of CNS cells and tissue of H. officinalis. The results of this study show that the CNS of these organisms absorbs in the region of 300 nm to 500 nm, and the tissue samples has a maximun of optical absorption near to 300 nm, besides were observed evident differences between the optical absorption spectra of CNS with injury and the control (without injury).

Obtención y Análisis del Espectro de Absorción Óptico de Sangre de Rata Fisher con Daño Hepático Mediante Espectroscopia Foto acústica / Obtaining and Analysis of Optical Absorption Spectrum of Fisher Rat Blood with Hepatic Damage by Photoacoustic Spectroscopy

Resumen: La Espectroscopia Fotoacústica (EFA), ha destacado de entre las técnicas fototérmicas por su versatilidad para la caracterización de diversos tipos de muestras, incluyendo las de tipo biológicas. En este estudio, se compararon y analizaron mediante EFA, las diferencias entre los espectros de absorción ópticos de sangre de ratas macho Fisher en tres casos, control (ratas sanas), con daño hepático, y con daño hepático tratadas con Curcuma longa. Los resultados experimentales demostraron diferencias en los espectros de absorción ópticos de cada caso analizado, por lo que EFA se propondría como una técnica complementaria, no convencional para el estudio del efecto de la Curcuma longa en daño hepático inducido en modelo animal.

Abstract: Photoacoustic Spectroscopy (PAS) stand outs among Photothermal techniques due to its versatility for the characterization of different types of materials, including biological samples. In this study, were compared and analyzed by PAS, the differences between the optical absorption spectra of blood of male Fisher rats, in three cases, control (healthy rats), liver damage and liver damage treated with Curcuma longa. The experimental results show differences in the optical absorption spectra of each analysed case, therefore PAS would be proposed as a non conventional complementary technique, to study the effect of Curcuma longa in induced liver damage for an animal model.

A role for tachykinins in the regulation of human sperm motility.

BACKGROUND: Tachykinins and tachykinin receptors are widely distributed in the male reproductive tract and appear to be involved in reproduction. However, the function and expression of tachykinins and their receptors in human spermatozoa remain poorly studied. We analysed the effects of tachykinins on sperm motility and characterized the population of tachykinin receptors in human spermatozoa. METHODS AND RESULTS: Motility analysis was performed following World Health Organization guidelines and we found that substance P (SP), human hemokinin-1 (hHK-1), neurokinin A (NKA) and neurokinin B (NKB) produced concentration-dependent increases in sperm progressive motility. The effects of tachykinins were antagonized by the NK(1) receptor-selective antagonist SR 140333, the NK(2) receptor-selective antagonist, SR 48968 and, to a lesser extent, also by the NK(3) receptor-selective antagonist SR 142801. Immunocytochemistry studies showed expression of the NK(1), NK(2) and NK(3) tachykinin receptor proteins in spermatozoa with different major sites of localization for each receptor. Western blot analysis confirmed the presence of tachykinin receptors in sperm cell homogenates. RT-PCR demonstrated expression of the genes that encode SP/NKA (TAC1), NKB (TAC3) and hHK-1 (TAC4) but not the genes TACR1, TACR2 and TACR3 encoding NK(1), NK(2) and NK(3) receptors, respectively. CONCLUSIONS: These results show for the first time that the NK(1), NK(2) and NK(3) tachykinin receptor proteins are present in human spermatozoa. Our findings suggest that tachykinins, probably acting through these three tachykinin receptors, play a role in the regulation of human sperm motility.

[Rheumatic activity in patients with heart valve replacements]. / Actividad reumática en pacientes sometidos a sustitución de válvulas cardíacas.

We made a comparative analyses of the clinical, laboratory and histological findings between two groups of patients: Group A was composed of rheumatic patients operated upon for valvular substitution. Group B included patients who were taken to cardiac surgery for non rheumatic reasons.

[Coronary circulation in asymmetrical hypertrophy of the interventricular septum. On a new pathogenic hypothesis]. / La circulación coronaria en la hipertrofía asimétrica del septum interventricular. Acerca de una nueva hipótesis patogénica.

Thirty-four patients with left ventricular hypertrophy were studied. In all cases the following parameters were analyzed: 1) Echocardiography:left ventricular diastolic and systolic diameters, ejection fraction, thickness and movement of interventricular septum and posterior wall of the left ventricle (LV) 2) Electrocardiography: R wave voltaje in precordial leads V2, V3 and V5 and electrical axis in frontal plane 3) Catheterization: intracavitary pressures in LV and aortic pressures 4) Left ventriculography: areas of altered contractility 5) Coronariography: distribution pattern of coronary arteries and number of first order branches of circumflex (CA) and anterior descending coronary arteries (ADCA). The population was divided into 2 groups. Group A (GA) was made up of 22 patients with concentric hypertrophy (CH) of the LV (15 with systemic hypertensive heart disease, 6 with aortic valvular stenosis and 1 idiopathic). Echocardiographic findings included posterior wall thickness (PWT) or septal thickness of 1.1. cm or more and interventricular septum-posterior wall thickness ratio (S/PW) of less than 1.3. Group B (GB) included 12 patients with asymmetric septal hypertrophy (ASH), idiopathic in 5, systemic hypertensive heart disease in 4 and aortic valvular stenosis in 3. In these patients the S/PW thickness ratio was greater than 1.3 and the thickness of either wall greater than 1.1. cm. When the data of the two groups were compared there were significant differences in relation to the presence of septal hypertrophy. The R wave voltage in V2, interventricular thickness and S/PW were greater in GB. In addition, septal movement was less in GB than in Group A (0.47 +/- 0.26 cm vs. 0.74 +/- 0.37 cm; P less than 0.05). PWT was also less in Group B than in A (B: 1.01 +/- 0.1 cm, A: 1.2 +/- 0.2 cm; P less than 0.001). The CA in Group B divided into fewer than 4 first order branches to the upper two thirds of the posterior and lateral walls of the LV in 91.6%. This distribution of circumflex branches was found in 31.8% of the patients in Group A (P less than 0.05). In Group B, the ADCA divided into septal branches with no more than 2 diagonal branches. The posterior descending artery dominated septal distribution in 100% of these cases (GA: 31.8%; P less than 0.05). The sum of the first order branches of the CA and the ADCA was 5.6 +/- 0.9 in Group A and 2.7 +/- 0.9 branches in Group B (P less than 0.01).(ABSTRACT TRUNCATED AT 400 WORDS)

[Arteriosclerosis obliterans. Treatment with angiotensin-converting enzyme inhibitors]. / Aterosclerosis obliterante. Tratamiento con inhibidores de la enzima convertidora de angiotensina (ECA).

We compare the effects of two of the main angiotensin convertase enzyme inhibitors, captopril and enalapril, aiming to evaluate their effects in the arterial circulation performance, micro-circulation, and changes in regional blood flow, assuming their property of lowering the angiotensin II blood levels, a very strong peripheral vasoconstrictor. We studied 22 patients: all of them with hypertension and/or skin ulcerations, dropping out those who had venous. They were evaluated periodically, clinically and with photoelectric plethysmography of lower extremities. To interpret the traces we designed an ideogram which gathered the plethysmographic behavior before and after the treatment. Nearly 80% showed considerable improvement in pain, functional capacity and plethysmographic traces patterns. healing of the ulcerations was achieved in all case. We propose some hypothesis to explain the good effect that we have observed.

[Multiple paragangliomas. The problem of its localization. Report of the first case studied with 131I meta-iodobenzylguanidine in our milieu and review of the literature]. / Paragangliomatosis múltiple. El problema de su localización. Informe del primer caso estudiado con [131I] meta-iodobenzilguanidina en nuestro medio y revisión de la literatura.

We report the case of a young woman, with an 8 year history of paroxysmal episodes of dyspnea, palpitations, blurred vision, tremors, precordial oppression and hypertension; the diagnosis of a chromaffin tumor was established, with an increase in serum and urine catecholamines level. She had three surgical interventions and also the following studies: abdominal and pelvic ultrasound, computed tomography, cavography; selective arteriography, and infusion of the meta iodobenzyl-guanidine 131, which localizes tissues hypersecretors rich in catecholamines.

Ebstein's anomaly, atrial paralysis and atrio-ventricular block: an uncommon association.

We report here the case of a 22-year-old female patient with an incomplete Ebstein's anomaly, complete heart block and atrial standstill. Atrial paralysis associated with Ebstein's anomaly is the most important feature, since there is a report of familial Ebstein's anomaly associated with atrial standstill but isolated cases have not been described. The patient presented with atypical chest pain and a symptomatic bradycardia of 37 beats per minute. A VVIR pacemaker was implanted. She has subsequently been symptom free.

Prevalence of sleep apnea and electrocardiographic disturbances in morbidly obese patients.

OBJECTIVE: To determine the prevalence of sleep apnea in morbidly obese patients and its relationship with cardiac arrhythmias. RESEARCH METHODS AND PROCEDURES: Fifty-two consecutive morbidly obese (body mass index > or = 40 kg/m2) outpatients from the Obesity Clinic of the National Institute of Nutrition Salvador Zubirán underwent two nights of polysomnography with standard laboratory techniques. Electrocardiographic polysomnography signals (Lead II) were evaluated by two experienced cardiologists, and sleep complaints were measured with a standard sleep questionnaire (Sleep Disorders Questionnaire). In order to make comparisons between groups with different severities of sleep-disordered breathing, we classified the patients in four groups using the apnea-hypopnea index (AHI): Group 1, AHI 5 < 15 (n = 10); Group 2, AHI 15 < 30 (n = 10); Group 3, AHI 30 < 65 (n = 14); Group 4, AHI > or = 65 (n = 17). RESULTS: A wide range of sleep-disordered breathing, ranging from AHI of 2.5 to 128.9 was found. Ninety-eight percent of the sample (n = 51) had an AHI > or = 5 (mean = 51 +/- 37), and 33% had severe sleep apnea with AHI > or = 65 with a mean nocturnal desaturation time of <65% over 135 minutes. Electrocardiographic abnormalities were present in 31% of the patients. Cardiac rhythm alterations showed an association with the level of sleep-disordered breathing and oxygen desaturation. DISCUSSION: We conclude that there is a high prevalence of sleep apnea in morbidly obese patients and that the risk for cardiac arrhythmias increases in this population in the presence of a severe sleep apnea (AHI > or = 65) with severe oxygen desaturation (SaO2 < or = 65%).

Prevalence of pulmonary hypertension and its association with respiratory disturbances in obese patients living at moderately high altitude.

OBJECTIVE: To determine the point prevalence of pulmonary hypertension (PH) and its relationship with respiratory disturbances in obese patients living at moderate altitude. SUBJECTS: A total of 57 obese patients comprised the final sample and consisted of 34 women and 23 men, with a mean age of 42.7+/-12.1 ys and a mean body mass index (BMI) 47.1+/-10.6 kg/m(2) (range from 30.1 to 76.1). The mean living altitude was 2248.7 m, range 2100-2400 m above sea level. MEASUREMENTS: Doppler echocardiography, pulmonary function tests, arterial blood gas analysis, and polysomnography were performed. RESULTS: Data showed that 96.5% of the studied sample had daytime PH defined as calculated systolic pulmonary artery pressure (PSAP) >30 mmHg (mean PSAP=50, s.d.=13 mmHg). The severity of diurnal PH was found to be related to the presence of alveolar hypoventilation and BMI. The main risk factor for severity of diurnal PH was hypoventilation with a significant odds ratio (OR) 7.96, 95% CI 1.35-46.84, BMI was (OR 1.12, 95% CI 1.02-1.25) and apnea/hypopnea index was not a predictor of pulmonary hypertension severity (OR 0.99, 95% CI 0.97-1.02). CONCLUSION: We concluded that prevalence of diurnal PH is high in obese patients living at moderate altitude, and that hypoventilation is the main risk factor associated with the severity of pulmonary hypertension.