Youth tobacco use in Latin America: What is the real extent of the problem?

INTRODUCTION: Cigarette consumption among teenagers is one of the most critical health-related risk behaviors. METHOD: Prospective study carried out in seven sites of five Latin American countries (Argentina [Cordoba, N=958, Corrientes, N=1013], Brazil [Curitiba, N=650; Uruguaiana, N=997], Cuba [Havana, N=1004], Mexico [Veracruz, N=991] and Paraguay [Ciudad del Este, N=868]) with public-school adolescents (aged 12-19 years). Respondents were asked to answer the California Student Tobacco Survey. RESULTS: 6550 adolescents took part in the survey (average age: 14 years). 38.5% (N=2517) "tried smoking" and 37.5% started smoking before the age of 12. Sixty-one percent of adolescents think that cigarettes are easily accessible; 41.7% considered that smokers have more friends; 88% indicated knowledge of the harms of smoking one to five cigarettes per day; 58.9% would smoke new cigarette types with less harmful substances; 27.8% have already used e-cigarettes; 28% have smoked hookah. Fifty-seven point five percent have been, in the past seven days, in the same room with someone who was smoking a cigarette; and 30.5% indicated that there were not any no-smoking rules inside their homes. Identifiable risk factors were (logistic regression analysis): smoking cigarettes offered by friends, smoking cigarettes with less harmful substances, knowing what a hookah is, being in the same room with a smoker in the past week. Identifiable protective factors against tobacco use were: knowing the health risks caused by smoking hookah and to have their own room. CONCLUSION: Youth tobacco use in Latin America is a major public health concern, and tobacco control measures are highly needed.

Sleep-related disorders in Latin-American children with atopic dermatitis: A case control study.

BACKGROUND: Atopic dermatitis (AD) has been associated with impairment of sleep. The aim of this study was to evaluate sleep disorders in AD Latin-American children (4-10 years) from nine countries, and in normal controls (C). METHODS: Parents from 454 C and 340 AD children from referral clinics answered the Children Sleep Habits Questionnaire (CSHQ), a one-week retrospective 33 questions survey under seven items (bedtime resistance, sleep duration, sleep anxiety, night awakening, parasomnias, sleep-disordered breathing and daytime sleepiness). Total CSHQ score and items were analysed in both C and AD groups. Spearman's correlation coefficient between SCORAD (Scoring atopic dermatitis), all subscales and total CSHQ were also obtained. RESULTS: C and AD groups were similar regarding age, however, significantly higher values for total CSHQ (62.2±16.1 vs 53.3±12.7, respectively) and items were observed among AD children in comparison to C, and they were higher among those with moderate (54.8%) or severe (4.3%) AD. Except for sleep duration (r=-0.02, p=0.698), there was a significant Spearman's correlation index for bedtime resistance (0.24, p<0.0001), sleep anxiety (0.29, p<0.0001), night awakening (0.36, p<0.0001), parasomnias (0.54, p<0.0001), sleep-disordered breathing (0.42, p<0.0001), daytime sleepiness (0.26, p<0.0001) and total CSHQ (0.46, p<0.0001). AD patients had significantly higher elevated body mass index. CONCLUSION: Latin-American children with AD have sleep disorders despite treatment, and those with moderate to severe forms had marked changes in CSHQ.

Sleep disorders in Latin-American children with asthma and/or allergic rhinitis and normal controls.

BACKGROUND: Asthma and/or allergic rhinitis have been associated with sleep disorders. The aim of this study was to evaluate sleep disorders in Latin-American children (4-10 years) from nine countries, with persistent asthma (A) and/or allergic rhinitis (AR) and in normal controls (C). METHODS: Parents from 454 C children and 700 A and/or AR children followed up in allergy reference clinics completed the Children's Sleep Habits Questionnaire (CSHQ) which is a retrospective one-week questionnaire composed of 33 questions composed of seven subscales (bedtime resistance, sleep duration, sleep anxiety, night wakings, parasomnias, sleep-disordered breathing and daytime sleepiness). The total scale of CSHQ and the subscales were compared between groups C and A+AR, A (n=285) vs. AR (n=390), and between controlled A (CA, n=103) vs. partially controlled/uncontrolled A (UA, n=182). RESULTS: The comparison between C and A+AR showed no significant differences in age (6.7 years vs. 7.0 years, respectively), mean Body Mass Index and total scale of CSHQ (53.3 vs. 63.2, respectively) and the subscales were significantly higher in the A+AR group. Comparison between groups A and AR, except for sleep anxiety, showed significantly higher values for CSHQ total scale (66.9 vs. 61.0, respectively) and subscales for group A. The UA group showed significantly higher values for total CSHQ scale and subscales in comparison to CA (71.1 vs. 59.4, respectively). CONCLUSIONS: Latin-American children with asthma and/or allergic rhinitis showed sleep disorders identified by the CSHQ when compared to normal controls. Despite being treated, asthma causes sleep impairment, especially when uncontrolled.

Cavity-enhanced room-temperature magnetometry using absorption by nitrogen-vacancy centers in diamond.

We demonstrate a cavity-enhanced room-temperature magnetic field sensor based on nitrogen-vacancy centers in diamond. Magnetic resonance is detected using absorption of light resonant with the 1042 nm spin-singlet transition. The diamond is placed in an external optical cavity to enhance the absorption, and significant absorption is observed even at room temperature. We demonstrate a magnetic field sensitivity of 2.5 nT/Hz, and project a photon shot-noise-limited sensitivity of 70 pT/Hz for a few mW of infrared light, and a quantum projection-noise-limited sensitivity of 250 fT/Hz for the sensing volume of ∼90 µm×90 µm×200 µm.

Electromagnetically induced transparency in a diamond spin ensemble enables all-optical electromagnetic field sensing.

We use electromagnetically induced transparency (EIT) to probe the narrow electron-spin resonance of nitrogen-vacancy centers in diamond. Working with a multipass diamond chip at temperatures 6-30 K, the zero-phonon absorption line (637 nm) exhibits an optical depth of 6 and inhomogeneous linewidth of ~30 GHz FWHM. Simultaneous optical excitation at two frequencies separated by the ground-state zero-field splitting (2.88 GHz) reveals EIT resonances with a contrast exceeding 6% and FWHM down to 0.4 MHz. The resonances provide an all-optical probe of external electric and magnetic fields with a projected photon-shot-noise-limited sensitivity of 0.2 V/cm/√[Hz] and 0.1 nT/√[Hz], respectively. Operation of a prototype diamond-EIT magnetometer measures a noise floor of ~/<1 nT/√[Hz] for frequencies above 10 Hz and Allan deviation of 1.3±1.1 nT for 100 s intervals. The results demonstrate the potential of diamond-EIT devices for applications ranging from quantum-optical memory to precision measurement and tests of fundamental physics.

Temperature- and magnetic-field-dependent longitudinal spin relaxation in nitrogen-vacancy ensembles in diamond.

We present an experimental study of the longitudinal electron-spin relaxation time (T1) of negatively charged nitrogen-vacancy (NV) ensembles in diamond. T1 was studied as a function of temperature from 5 to 475 K and magnetic field from 0 to 630 G for several samples with various NV and nitrogen concentrations. Our studies reveal three processes responsible for T1 relaxation. Above room temperature, a two-phonon Raman process dominates; below room temperature, we observe an Orbach-type process with an activation energy of 73(4) meV, which closely matches the local vibrational modes of the NV center. At yet lower temperatures, sample dependent cross-relaxation processes dominate, resulting in temperature independent values of T1 from milliseconds to minutes. The value of T1 in this limit depends sensitively on the magnetic field and can be tuned by more than 1 order of magnitude.

Dynamic stabilization of the optical resonances of single nitrogen-vacancy centers in diamond.

We report electrical tuning by the Stark effect of the excited-state structure of single nitrogen-vacancy (NV) centers located ≲100 nm from the diamond surface. The zero-phonon line (ZPL) emission frequency is controllably varied over a range of 300 GHz. Using high-resolution emission spectroscopy, we observe electrical tuning of the strengths of both cycling and spin-altering transitions. Under resonant excitation, we apply dynamic feedback to stabilize the ZPL frequency. The transition is locked over several minutes and drifts of the peak position on timescales ≳100 ms are reduced to a fraction of the single-scan linewidth, with standard deviation as low as 16 MHz (obtained for an NV in bulk, ultrapure diamond). These techniques should improve the entanglement success probability in quantum communications protocols.

Temperature dependence of the nitrogen-vacancy magnetic resonance in diamond.

The temperature dependence of the magnetic-resonance spectra of nitrogen-vacancy (NV-) ensembles in the range of 280-330 K was studied. Four samples prepared under different conditions were analyzed with NV- concentrations ranging from 10 ppb to 15 ppm. For all samples, the axial zero-field splitting (ZFS) parameter D was found to vary significantly with temperature, T, as dD/dT=-74.2(7) kHz/K. The transverse ZFS parameter E was nonzero (between 4 and 11 MHz) in all samples, and exhibited a temperature dependence of dE/(EdT)=-1.4(3)x10{-4} K-1. The results might be accounted for by considering local thermal expansion. The temperature dependence of the ZFS parameters presents a significant challenge for diamond magnetometers and may ultimately limit their bandwidth and sensitivity.

Production and detection of atomic hexadecapole at Earth's magnetic field.

Optical magnetometers measure magnetic fields with extremely high precision and without cryogenics. However, at geomagnetic fields, important for applications from landmine removal to archaeology, they suffer from nonlinear Zeeman splitting, leading to systematic dependence on sensor orientation. We present experimental results on a method of eliminating this systematic error, using the hexadecapole atomic polarization moment. In particular, we demonstrate selective production of the atomic hexadecapole moment at Earth's magnetic field and verify its immunity to nonlinear Zeeman splitting. This technique promises to eliminate directional errors in all-optical atomic magnetometers, potentially improving their measurement accuracy by several orders of magnitude.

Modal analysis and nonlinear characterization of an airborne power ultrasonic transducer with rectangular plate radiator.

Some industrial processes like particle agglomeration or food dehydration among others can be enhanced by the use of power ultrasonic technologies. These technologies are based on an airborne power ultrasonic transducer (APUT) constituted by a pre-stressed Langevin-type transducer, a mechanical amplifier and an extensive plate radiator. In order to produce the desired effects in industrial processing, the transducer has to vibrate in an extensional mode driving an extensive radiator in the desired flexural mode with high amplitude displacements. Due to the generation of these high amplitude displacements in the radiator surfaces, non-linear effects like frequency shifts, hysteresis or modal interactions, among others, may be produced in the transducer behavior. When any nonlinear effect appears, when applying power, the stability and efficiency of this ultrasonic technology decreases, and the transducer may be damaged depending on the excitation power level and the nature of the nonlinearity. In this paper, an APUT with flat rectangular radiator is presented, as the active part of an innovative system with stepped reflectors. The nonlinear behavior of the APUT has been characterized numerically and experimentally in case of the modal analysis and experimentally in the case of dynamic analysis. According to the results obtained after the experiments, no modal interactions are expected, nor do other nonlinear effects.

Functional Outcomes 18 Months After Total and Midarm Transplantation: A Case Report.

BACKGROUND: The function reported after arm transplantation is deemed beneficial relative to the marked disability that upper arm amputation causes. OBJECTIVE: We report a 51-year-old man with a Disabilities of the Arm, Shoulder and Hand (DASH) score of 75.83 who underwent bilateral arm transplantation in October 2015. PROCEDURE: The right arm was transplanted at the glenohumeral joint level, including transplantation of the humeral head, joint capsule, and rotator cuff ligaments and tendons. Additionally, neurorrhaphies were performed at the origin of the terminal branches of the brachial plexus, including the axillary and musculocutaneous nerves. Therefore, this was considered a total arm transplantation. The left arm was transplanted at the transhumeral level, with complete transplantation of the biceps and triceps brachii, and terminolateral neurorrhaphy of the donor musculocutaneous nerve to the receptor radial nerve. A maintenance triple immunosuppression scheme was administered, with tacrolimus levels kept at 10 ng/mL. RESULTS: At 18 months post-transplantation, the intrinsic musculature in the left hand showed electrical registry, DASH score was 67.5, Carroll test score was 28 in both extremities, Hand Transplant Score System was 67.5 in the right extremity and 77.5 in the left extremity, and Short Form-36 score was 96.1. The patient was healthy, with restored body integrity. He could lift medium-sized weightless objects, eat and go to the bathroom by himself, drink liquids with bimanual grasp, swim, dress almost independently, and drive. CONCLUSION: The functional evolution of the patient was similar to previously reported transplanted arms, even though the right arm transplant involved the glenohumeral joint and axillary and musculocutaneous nerve repair.

Solution nuclear magnetic resonance spectroscopy on a nanostructured diamond chip.

Sensors using nitrogen-vacancy centers in diamond are a promising tool for small-volume nuclear magnetic resonance (NMR) spectroscopy, but the limited sensitivity remains a challenge. Here we show nearly two orders of magnitude improvement in concentration sensitivity over previous nitrogen-vacancy and picoliter NMR studies. We demonstrate NMR spectroscopy of picoliter-volume solutions using a nanostructured diamond chip with dense, high-aspect-ratio nanogratings, enhancing the surface area by 15 times. The nanograting sidewalls are doped with nitrogen-vacancies located a few nanometers from the diamond surface to detect the NMR spectrum of roughly 1 pl of fluid lying within adjacent nanograting grooves. We perform 1H and 19F nuclear magnetic resonance spectroscopy at room temperature in magnetic fields below 50 mT. Using a solution of CsF in glycerol, we determine that 4 ± 2 × 1012 19F spins in a 1 pl volume can be detected with a signal-to-noise ratio of 3 in 1 s of integration.Nitrogen vacancy (NV) centres in diamond can be used for NMR spectroscopy, but increased sensitivity is needed to avoid long measurement times. Kehayias et al. present a nanostructured diamond grating with a high density of NV centres, enabling NMR spectroscopy of picoliter-volume solutions.

Effect of task decision on P300.

Previous studies have shown that the structure of an experimental task may modulate P300 (P3) responsiveness to task-related test stimuli. In this study, four tasks were compared to study possible effects of decision type on P3s to rare and frequent visual word stimuli. One or three oddballs were designated in two separate experiments. Subjects in each experiment viewed randomized and repeated presentations of nine 5- to 8-letter words, and performed each of four target detection and choice discrimination tasks: (1) silent counting of oddball(s), (2) button-press to oddball(s), (3) choice response ('yes' or 'no') to oddball(s) and frequents, and (4) choice button-press to oddball(s) and frequents. Although oddball stimuli elicited characteristic 'target' P3s over the parietal scalp, there was no significant effect of task type on the oddball-evoked P3. Frequents tended to elicit larger P3s in the choice discrimination tasks (yes/no, go/go) than in target-detection tasks (counting, go/no-go), indicating a selective effect of decision type on P3s to frequent-category events.

Prevalence of diarrheogenic Escherichia coli and rotavirus among children from Botucatu, São Paulo State, Brazil.

In a one-year prospective study carried out to define the role of rotavirus and Escherichia coli in local childhood diarrhea, we determined the prevalence of both agents in 54 diarrheic children attending a health center in Botucatu. Diarrheogenic E. coli (DEC) strains were characterized by O:H serotyping, a search for virulence genetic markers, and assays of adherence to HEp-2 cells. Except for enteroaggregative E. coli (EAEC), no other DEC category was detected in the children's stools. Both EAEC and rotavirus were isolated from 22 of the 54 (41.0%) diarrheic children as single agents or in combination with other enteropathogens. However, when considering the presence of a single agent, EAEC was dominant and isolated from 20.4% of the patients, whereas rotavirus was detected in 14.8%. These results indicate that rotavirus and EAEC play a significant role as agents of childhood diarrhea in the local population.

Silica wool filtration (SIFT) assay: a simple system to estimate the percentage of acrosome-reacted sperm.

OBJECTIVE: To develop a simple assay using the silica wool filtration (SIFT) procedure to estimate percentage of acrosome-reacted (AR) sperm. SETTING: Private andrology laboratory. MATERIALS AND METHODS: Capacitated sperm processed by the SIFT procedure to remove nonviable sperm and those with broken membrane were acrosome reacted by induction with a calcium ionophore. Following the acrosome reaction, the sample was processed by the SIFT procedure. Sperm concentration and acrosomal status were also determined before and after the SIFT procedure. RESULTS: The SIFT procedure prevented AR sperm from filtering (mean +/- SD, 22.2 +/- 1.9 vs. 9.8 +/- 4.9%). The mean percent of sperm retained in the filter (SIFT assay: 61.8 +/- 21.5%) was significantly higher than the percent of AR sperm estimated by a staining technique (26.4 +/- 7.3%), but they were significantly correlated (r = .34) with each other. The filtration of capacitated sperm prior to induction of the acrosome reaction eliminated, or at least minimized, the possibility of falsely increasing the percent of AR sperm estimated by the SIFT assay. The higher estimate obtained by SIFT assay, therefore, suggests that it may be estimating sperm at various stages that are undergoing the acrosome reaction. CONCLUSION: The findings suggest that the SIFT assay could be used to estimate the percentage of AR spermatozoa.

Effects of electromagnetic extracorporeal shock wave lithotripsy on the fine structure of the liver and gallbladder of the rabbit.

The fine structure of the liver and gallbladder of rabbits submitted to lithotripsy was studied with transmission electron microscopy. Alterations found in both organs involved capilaries, venules and small veins as well as neighboring tissues. In the liver the most important alterations were seen in those areas located about central veins. These consisted in mitochondrial vacuolation, increase in the cytoplasmic electrondensity, and necrosis. In the gallbladder different stages of epithelial damage and regeneration (i.e. mitoses) were observed. Vascular damage was characterized by mitochondrial swollen and increase of nuclear and cytoplasmic electrondensities. The gallbladder's stroma displayed cell vacuolation, pyknosis, and edema. It is proposed that the damage produced by lithotripsy results from a direct colision of red blood cells upon blood vessels. Tissue damage was considered focal and in most cases reversible.

[Cervical cytology: findings dependent on the bio-collector]. / Citología cervical: hallazgos dependientes del biocolector.

The purpose of this analysis was to prospectively evaluate two biocollectors designed for ecto and endocervix Accelon and spatula, for with two gynecologists-obstetricians taken double cervical sample, simultaneous, in 100 patients going to Outpatient Department. The pathologist did not know which slides were taken with which biocollector, Collectors as well as biocollectors were evaluated by formula Kappa and Contingency tables. Variable nominal of study was quality sample following Bethesda's criteria. Cytological findings observed in slides taken with accellon and spatula respectively were squamous cells 100% a 96%. although proportionally spatula captures greater cellularity of squamous epithelium. From metaplasic cells 17 and 8%. From cylindric epithelium cells, 81 and 65%; and here accellon aptures proportionally greater amount of cylindric cels, 10 or more Leukocytes in presence of cylindric cells at 1X1000 in immersion; 4 y 0% hematies, 18 and 14% without impeding cytological interpretation. And microorganisms. 3 and 10%. As to conclusions: There was concordance for the two collectors; and it was not so for biocollectors, which detect neoplastic epithelial lesions, being a better collector of endocervical component, the Accellon an it favors objective criteria for the cytologic diagnostic of endocervicitis. As to spatula it captures more squamous component and it favors cytologic diagnosis of microorganism that affect this area. Both biocollectors are needed to compensate limitations, and so, improve the specimens that permit to lower false negatives.

[Density, growth and survival of Lyropecten (Nodipecten) nodosus (Pteroida: Pectinidae) juveniles in suspended-frame culture in Golfo de Cariaco, Venezuela]. / Densidad, crecimiento y supervivencia de juveniles de Lyropecten (Nodipecten) nodosus (pteroida: pectinidae) en cultivo suspendido en el Golfo de Cariaco, Venezuela.

The effect of culture density on growth and survival of juveniles was studied in the scallop Lyropecten nodosus with intermediate hanging cultures in Golfo de Cariaco, Sucre state, Venezuela, from December 1993 to July 1994. Six spat-densities (7, 15, 30, 60, 125 and 250 scallops/nets) were evaluated. The initial shell height and dry mass tissue were 9.4 +/- 0.18 mm and 0.007 +/- 0.0026 g, respectively. The specimens were placed into pearl nets and suspended in a long line at 8 m depth. Growth patterns of somatic tissue were similar, but with different magnitudes and inverse proportionality to culture density. No effect of density was observed on survival. These results suggest that intraspecific competition of cultivated scallops cause stress, which affects growth but not survival. We suggest as strategy for the management of culture density, successive density reductions, to obtain in a six months culture (intermediate culture) specimens of 50 mm in shell height in order to start the final culture period.

Power ultrasonic transducers with extensive radiators for industrial processing.

High-power ultrasonics (HPU) is a green emerging technology that offers a great potential for a wide range of industrial processes. Nevertheless such potential have remained restricted during many years to a limited number of applications which reached commercial development. The possible major problem for extending the range of HPU industrial applications has been the lack of power ultrasonic transducers for large-scale application, adapted to the requirements of each specific problem with high efficiency and power capacity. A new family of HPU transducers with extensive radiators have been recently introduced. It comprises a variety of transducer types designed with the radiators adapted to different specific uses in fluids and multi-phase media. Such transducers implement high power capacity, high efficiency and radiation pattern control. In addition, their design incorporate strategies to eliminate or reduce modal interactions produced at high power as a consequence of their nonlinear behaviour. The introduction of such new transducers has significantly contributed to the development at semi-industrial and industrial level of a number of processes in the food and beverage industry, in environment and in manufacturing. This paper deals with the basic structure and main characteristics of such transducers as well as their performance in the developed application processes.

Reconstrucción microquirúrgica en el trauma pediátrico / Microsurgical reconstruction in pediatric trauma

Introduction: We present a series of clinical cases in which free tissue transfer was performed to repair traumatic defects in 4 pediatric patients (5 free flaps). Each clinical case was analyzed for free flap indication, complication and outcome. Case reports: There were a total of 2 musculotaneous flaps (latissimus dorsi and rectus abdominis) and 3 fasciocutaneous flaps (anterolateral thigh). One case required surgical revision and no flap losses are reported. At present patients are in rehabilitation phase after an average of 12 months of follow-up. This series is the first national communication of microsurgical reconstruction in the pediatric trauma patient.

Introducción: Se presenta una serie de casos clínicos en la cual se realiza transferencia libre de tejidos para solucionar defectos de cobertura de origen traumático en 4 pacientes pediátricos (5 colgajos libres). Se analiza cada caso clínico, la indicación de colgajo libre, complicaciones y resultados. Casos clínicos: Se realizaron 2 colgajos musculares (dorsal ancho y recto abdominal) y 3 colgajos fasciocutáneos (anterolateral de muslo). Sólo un caso requirió revisión quirúrgica, no tuvimos pérdidas de colgajos y hasta la fecha los pacientes se encuentran en fase de rehabilitación, tras un seguimiento medio de 12 meses. Esta serie es la primera comunicación nacional de reconstrucción microquirúrgica en pacientes pediátricos traumáticos.