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1.
Hum Reprod ; 38(8): 1613-1620, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37329261

RESUMO

STUDY QUESTION: Is there an association between iron intake and ovarian reserve among women seeking fertility care? SUMMARY ANSWER: Supplemental iron intake above 45 mg/day is associated with lower ovarian reserve among women seeking fertility care. WHAT IS KNOWN ALREADY: Although the literature regarding iron intake in relation to ovarian reserve is scant and inconsistent, some evidence suggests that iron may have gonadotoxic effects. STUDY DESIGN, SIZE, DURATION: This observational study included 582 female participants attending the Massachusetts General Hospital Fertility Center (2007-2019) enrolled in the Environment and Reproductive Health (EARTH) Study. PARTICIPANTS/MATERIALS, SETTING, METHODS: Iron intake was estimated using a validated food frequency questionnaire. Markers of ovarian reserve included antral follicle count (AFC) (assessed via transvaginal ultrasound) and Day 3 FSH, both obtained during the course of an infertility evaluation. MAIN RESULTS AND THE ROLE OF CHANCE: Participants had a median age of 35 years and median total iron intake of 29 mg/day. Total iron intake was inversely related to AFC and this association was driven by intake of supplemental iron. Compared to women with a supplemental iron intake of ≤20 mg/day, women consuming 45-64 mg/day of supplemental iron had a 17% (-35%, 0.3%) lower AFC and women consuming ≥65 mg/day of supplemental iron had a 32% (-54%, -11%) lower AFC after adjusting for potential confounders (P, linear trend = 0.003). Similarly, in a multivariable-adjusted analysis, Day 3 FSH levels were 0.9 (0.5, 1.3) IU/ml higher among women with a supplemental iron intake of ≥65 mg/day when compared to women with a supplemental iron intake of ≤20 mg/day (P, linear trend = 0.02). LIMITATIONS, REASONS FOR CAUTION: Iron intake was estimated using a method that relies on self-report and we had no biomarkers of iron status in our participants; only 36 women consumed ≥45 mg/day of supplemental iron. WIDER IMPLICATIONS OF THE FINDINGS: Since all study participants were seeking fertility treatment, our findings may not apply to women in the general population. Although our findings are consistent with studies of women with iron overload, given the paucity of literature on this topic, it is essential that this question is revisited in studies designed to better understand the dose-response relation of this association across the entire distribution of ovarian reserve and the risk-benefit balance of pre-conceptional iron supplementation given its many positive effects on pregnancy outcomes. STUDY FUNDING/COMPETING INTEREST(S): The project was funded by Grants R01ES022955, R01ES033651, R01ES009718, P30ES000002, and P30DK046200 from the National Institutes of Health. N.J.-C. was supported by a Fulbright Scholarship. N.J.-C., M.M., L.M.-A., E.O.-P., S.W., I.S., and J.E.C. declare no conflict of interest related to the work in the manuscript. R.H. has received grants from the National Institute of Environmental Health Sciences. TRIAL REGISTRATION NUMBER: N/A.


Assuntos
Infertilidade , Reserva Ovariana , Gravidez , Feminino , Humanos , Adulto , Folículo Ovariano/fisiologia , Estudos Prospectivos , Infertilidade/terapia , Hormônio Foliculoestimulante
2.
Harm Reduct J ; 19(1): 139, 2022 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-36503497

RESUMO

BACKGROUND: Female sex workers (FSW) have been disproportionately impacted by the Covid-19 crisis. Data show increases of police violence toward key populations (KP), likely a consequence of their role in enforcing health government measures. This study aimed to identify factors associated with police violence experienced by FSW during the Covid-19 crisis in Argentina. METHODS: EPIC is a multi-country, cross-sectional, community-based research program evaluating the impact of Covid-19 among KP. In Argentina, the study was conducted in collaboration with FSW community-based organizations (CBO). Participants completed an online survey (October 2020-April 2021). Police violence was measured as having experienced episodes of violence (physical, verbal, psychological or sexual) by security forces since the start of the health crisis. Factors associated with police violence were assessed in logistic regression models. RESULTS: Among 173 respondents, median age was 34 [IQR 27-42], 39.3% were transgender women (TW), 78.1% declared sex work as their only income and 71.7% mentioned their financial situation has deteriorated with the health crisis. Nearly half of FSW (44.5%) reported experiencing police violence within the first year of the Covid-19 pandemic, and among them, 76.6% declared more frequent violence episodes since the beginning of the health crisis. After adjustment for age, being a TW (aOR [95% CI] = 2.71 [1.21;6.05]), reporting non-injection drug use (2.92 [1.02;8.36]), having a considerably deteriorated financial situation (3.67 [1.47;9.21]), having had a consultation with a CBO worker for medical care/treatments (5.56 [2.15;14.37]) and declaring fear or experiences of discrimination by physicians/other health workers (2.97 [1.21;7.29]), since the beginning of the Covid-19 health crisis, were independently associated with police violence. CONCLUSIONS: FSW in Argentina have experienced an increase in police violence since the beginning of the health crisis. Belonging to multiple KP (FSW, TW, people who use drugs) increases the likelihood of experiencing police violence, highlighting the need of an intersectional approach to develop interventions to reduce stigma and violence against FSW. CBOs have provided essential support and services during the crisis to FSWs, and other KPs, who may have avoided traditional healthcare structures due to fear or experiences of discrimination.


Assuntos
COVID-19 , Infecções por HIV , Profissionais do Sexo , Feminino , Humanos , Adulto , Estudos Transversais , Pandemias , Infecções por HIV/epidemiologia
3.
J Eur Acad Dermatol Venereol ; 36(1): 68-75, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34653265

RESUMO

BACKGROUND: The Psoriasis Area and Severity Index (PASI) score is commonly used in clinical practice and research to monitor disease severity and determine treatment efficacy. Automating the PASI score with deep learning algorithms, like Convolutional Neural Networks (CNNs), could enable objective and efficient PASI scoring. OBJECTIVES: To assess the performance of image-based automated PASI scoring in anatomical regions by CNNs and compare the performance of CNNs to image-based scoring by physicians. METHODS: Imaging series were matched to PASI subscores determined in real life by the treating physician. CNNs were trained using standardized imaging series of 576 trunk, 614 arm and 541 leg regions. CNNs were separately trained for each PASI subscore (erythema, desquamation, induration and area) in each anatomical region (trunk, arms and legs). The head region was excluded for anonymity. Additionally, PASI-trained physicians retrospectively determined image-based subscores on the test set images of the trunk. Agreement with the real-life scores was determined with the intraclass correlation coefficient (ICC) and compared between the CNNs and physicians. RESULTS: Intraclass correlation coefficients between the CNN and real-life scores of the trunk region were 0.616, 0.580, 0.580 and 0.793 for erythema, desquamation, induration and area, respectively, with similar results for the arms and legs region. PASI-trained physicians (N = 5) were in moderate-good agreement (ICCs 0.706-0.793) with each other for image-based PASI scoring of the trunk region. ICCs between the CNN and real-life scores were slightly higher for erythema (0.616 vs. 0.558), induration (0.580 vs. 0.573) and area scoring (0.793 vs. 0.694) than image-based scoring by physicians. Physicians slightly outperformed the CNN on desquamation scoring (0.580 vs. 0.589). CONCLUSIONS: Convolutional Neural Networks have the potential to automatically and objectively perform image-based PASI scoring at an anatomical region level. For erythema, desquamation and induration scoring, CNNs performed similar to physicians, while for area scoring CNNs outperformed physicians on image-based PASI scoring.


Assuntos
Psoríase , Algoritmos , Humanos , Redes Neurais de Computação , Psoríase/diagnóstico por imagem , Estudos Retrospectivos , Índice de Gravidade de Doença
4.
Philos Trans A Math Phys Eng Sci ; 377(2141): 20170444, 2019 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-30967058

RESUMO

The speed at which fusion energy can be deployed is considered. Several economical factors are identified that impede this speed. Most importantly, the combination of an unprecedentedly high investment level needed for the proof of principle and the relatively long construction time of fusion plants precludes an effective innovation cycle. The valley of death is discussed, i.e. the period when a large investment is needed for the construction of early generations of fusion reactors, when there is no return yet. It is concluded that, within the mainstream scenario-a few DEMO reactors towards 2060 followed by generations of relatively large reactors-there is no realistic path to an appreciable contribution to the energy mix in the twenty-first century if economic constraints are applied. In other words, fusion will not contribute to the energy transition in the time frame of the Paris climate agreement. Within the frame of this analysis, the development of smaller, cheaper and most importantly, fast-to-build fusion plants could possibly represent an option to accelerate the introduction of fusion power. Whether this is possible is a technical question that is outside the scope of this paper, but this question is addressed in other contributions to the Royal Society workshop. This article is part of a discussion meeting issue 'Fusion energy using tokamaks: can development be accelerated?'.

5.
Rev Sci Instrum ; 90(2): 023501, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30831775

RESUMO

In this paper, we present a method for numerical computation of collective Thomson scattering (CTS). We developed a forward model, eCTS, in the electrostatic approximation and benchmarked it against a full electromagnetic model. Differences between the electrostatic and the electromagnetic models are discussed. The sensitivity of the results to the ion temperature and the plasma composition is demonstrated. We integrated the model into the Bayesian data analysis framework Minerva and used it for the analysis of noisy synthetic data sets produced by a full electromagnetic model. It is shown that eCTS can be used for the inference of the bulk ion temperature. The model has been used to infer the bulk ion temperature from the first CTS measurements on Wendelstein 7-X.

6.
Rev Sci Instrum ; 89(8): 083507, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30184679

RESUMO

Two methods for fast analysis of Collective Thomson Scattering (CTS) spectra are presented: Function Parametrization (FP) and feedforward Artificial Neural Networks (ANNs). At this time, a CTS diagnostic is being commissioned at the Wendelstein 7-X (W7-X) stellarator, with ion temperature measurements in the plasma core as its primary goal. A mapping was made from a database of simulated CTS spectra to the corresponding ion and electron temperatures (Ti and Te ). The mean absolute mapping errors are 4.2% and 9.9% relative to the corresponding Ti , for the ANN and FP, respectively, for spectra with Gaussian noise equivalent to 10% of the average of the spectral maxima in the database at 650 sampling points per GHz and within a limited parameter space. Although FP provides some insight into the information contents of the CTS spectra, ANNs provide a higher accuracy and noise robustness, are easier to implement, and are more adaptable to a larger parameter space. These properties make ANN mappings a promising all-round method for fast CTS data analysis. Addition of impurity concentrations to the current parameter space will enable fast bulk ion temperature measurements in the plasma core region of W7-X.

7.
Braz J Med Biol Res ; 51(5): e6754, 2018 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-29590258

RESUMO

Cell adhesion in three-dimensional scaffolds plays a key role in tissue development. However, stem cell behavior in electrospun scaffolds under perfusion is not fully understood. Thus, an investigation was made on the effect of flow rate and shear stress, adhesion time, and seeding density under direct perfusion in polycaprolactone electrospun scaffolds on human dental pulp stem cell detachment. Polycaprolactone scaffolds were electrospun using a solvent mixture of chloroform and methanol. The viable cell number was determined at each tested condition. Cell morphology was analyzed by confocal microscopy after various incubation times for static cell adhesion with a high seeding density. Scanning electron microscopy images were obtained before and after perfusion for the highest flow rate tested. The wall pore shear stress was calculated for all tested flow rates (0.005-3 mL/min). An inversely proportional relationship between adhesion time with cell detachment under perfusion was observed. Lower flow rates and lower seeding densities reduced the drag of cells by shear stress. However, there was an operational limit for the lowest flow rate that can be used without compromising cell viability, indicating that a flow rate of 0.05 mL/min might be more suitable for the tested cell culture in electrospun scaffolds under direct perfusion.


Assuntos
Polpa Dentária/citologia , Perfusão , Poliésteres , Células-Tronco/citologia , Alicerces Teciduais , Adesão Celular , Técnicas de Cultura de Células , Humanos
8.
Phys Rev E Stat Nonlin Soft Matter Phys ; 78(4 Pt 2): 046405, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18999541

RESUMO

A potential buildup in front of a magnetized cascaded arc hydrogen plasma source is explored via E x B rotation and plate potential measurements. Plasma rotation approaches thermal speeds with maximum velocities of 10 km/s. The diagnostic for plasma rotation is optical emission spectroscopy on the Balmer-beta line. Asymmetric spectra are observed. A detailed consideration is given on the interpretation of such spectra with a two distribution model. This consideration includes radial dependence of emission determined by Abel inversion of the lateral intensity profile. Spectrum analysis is performed considering Doppler shift, Doppler broadening, Stark broadening, and Stark splitting.

9.
Rev Sci Instrum ; 79(1): 013505, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18248032

RESUMO

A highly sensitive imaging Thomson scattering system was developed for low temperature (0.1-10 eV) plasma applications at the Pilot-PSI linear plasma generator. The essential parts of the diagnostic are a neodymium doped yttrium aluminum garnet laser operating at the second harmonic (532 nm), a laser beam line with a unique stray light suppression system and a detection branch consisting of a Littrow spectrometer equipped with an efficient detector based on a "Generation III" image intensifier combined with an intensified charged coupled device camera. The system is capable of measuring electron density and temperature profiles of a plasma column of 30 mm in diameter with a spatial resolution of 0.6 mm and an observational error of 3% in the electron density (n(e)) and 6% in the electron temperature (T(e)) at n(e) = 4 x 10(19) m(-3). This is achievable at an accumulated laser input energy of 11 J (from 30 laser pulses at 10 Hz repetition frequency). The stray light contribution is below 9 x 10(17) m(-3) in electron density equivalents by the application of a unique stray light suppression system. The amount of laser energy that is required for a n(e) and T(e) measurement is 7 x 10(20)n(e) J, which means that single shot measurements are possible for n(e)>2 x 10(21) m(-3).

10.
Phys Chem Chem Phys ; 8(15): 1761-74, 2006 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-16633660

RESUMO

The decreasing availability of energy and concern about climate change necessitate the development of novel sustainable energy sources. Fusion energy is such a source. Although it will take several decades to develop it into routinely operated power sources, the ultimate potential of fusion energy is very high and badly needed. A major step forward in the development of fusion energy is the decision to construct the experimental test reactor ITER. ITER will stimulate research in many areas of science. This article serves as an introduction to some of those areas. In particular, we discuss research opportunities in the context of plasma-surface interactions. The fusion plasma, with a typical temperature of 10 keV, has to be brought into contact with a physical wall in order to remove the helium produced and drain the excess energy in the fusion plasma. The fusion plasma is far too hot to be brought into direct contact with a physical wall. It would degrade the wall and the debris from the wall would extinguish the plasma. Therefore, schemes are developed to cool down the plasma locally before it impacts on a physical surface. The resulting plasma-surface interaction in ITER is facing several challenges including surface erosion, material redeposition and tritium retention. In this article we introduce how the plasma-surface interaction relevant for ITER can be studied in small scale experiments. The various requirements for such experiments are introduced and examples of present and future experiments will be given. The emphasis in this article will be on the experimental studies of plasma-surface interactions.


Assuntos
Fusão Nuclear , Reatores Nucleares/instrumentação , Gases , Íons , Propriedades de Superfície , Temperatura , Trítio/química
11.
Phys Rev Lett ; 94(1): 015003, 2005 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-15698091

RESUMO

The first results of the Dynamic Ergodic Divertor in TEXTOR, when operating in the m/n=3/1 mode configuration, are presented. The deeply penetrating external magnetic field perturbation of this configuration increases the toroidal plasma rotation. Staying below the excitation threshold for the m/n=2/1 tearing mode, this toroidal rotation is always in the direction of the plasma current, even if the toroidal projection of the rotating magnetic field perturbation is in the opposite direction. The observed toroidal rotation direction is consistent with a radial electric field, generated by an enhanced electron transport in the ergodic layers near the resonances of the perturbation. This is an effect different from theoretical predictions, which assume a direct coupling between rotating perturbation and plasma to be the dominant effect of momentum transfer.

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