Search

Using a critical race theory framework and a convergent mixed-method design, this study examined the relationship between coping with stress and psychological distress among Black U.S. Americans ( N = 155) during the COVID-19 pandemic in the context of race-based stressors (e.g., anti-Black racism). Path analysis revealed mixed support for hypotheses; avoidant coping was positively related to all measured facets of psychological distress, whereas socially supported coping was associated with none. Self-sufficient coping was negatively associated with only depressive symptoms. Qualitative analysis revealed four salient themes: (a) Race and the COVID-19 Pandemic, (b) Complex Pandemic Related Changes to Life, (c) Emotional Responses to the Pandemic, and (d) Coping with the COVID Pandemic. These themes suggested the pandemic disrupted participants’ ability to engage in, or effectively use, typically adaptive coping strategies and distress was exacerbated by fears for the safety of other Black U.S. Americans. Implications for training, practice, research, and advocacy are discussed.

The genetic diversity of hepatitis B virus (HBV) was defined on the basis of the characterisation of the major determinants in the antigenic loop of HBs antigen (Ag). Historically, nine subtypes were defined. Recently, based on sequence analysis, HBV genomes have been classified into eight genotypes (A-H) which present distinct geographical distributions. Genetic mutants may have a selective advantage in patients treated with passive or active immunization (hepatitis B immune globulin or vaccine). Anti-viral treatment can be responsible for the emergence of escape mutants with resistant mutations in the polymerase gene. These substitutions can lead to changes on HBsAg structure. The lack of detection of several envelope mutant viruses by some commercial HBsAg assays has been demonstrated. Substitutions involving precore/core region have also been found to prevent HBeAg synthesis.

Sequence analysis of human erythroviruses shows an organization into three genotypes; genotype 1 with B19 Parvovirus (B19 V) and 2 new genotypes with a genetic diversity markedly distinct from that of B19 V. The frequency of each genotype depends on geographic origin and population. Human erythroviruses infection can be transmitted by transfusion. In immunocompetent recipients, B19 V exposure is generally inconsequential, since a large proportion is immunized. However, such a contamination may have severe clinical outcome in not immunized patients with shortened red cell survival, in seronegative pregnant women and in immunocompromised patients. No prevention of blood transmission is currently performed, but a preventive strategy could be discussed for at-risk recipients. In plasma derivatives, B19VDNA screening is done with a threshold of 104 IU/mL. With recent data of a new classification on the human erythroviruses genotypes, DNA testing assays would be validated in accordance with genetic variability, in order to guarantee optimal safety.

Quasiperiodicity is a form of spatial order that has been observed in quasicrystalline matter but not light. We construct a quasicrystalline surface out of a light emitting diode. Using a nanoscale waveguide as a microscope (NSOM), we directly image the light field at the surface of the diode. Here we show, using reciprocal space representations of the images, that the light field is quasiperiodic. We explain the structure of the light field with wave superposition. Periodic ordering is limited to at most six-fold symmetry. The light field exhibits 12-fold quasisymmetry, showing order while disproving periodicity. This demonstrates that a new class, consisting of projections from hyperspace, exists in the taxonomy of light ordering.

We present herein a digestion method based on high-temperature (260 °C) microwave heating and strong acidic media in order to perform a complete digestion of nonwoven textiles, which can be found in face masks. In particular, this protocol allows the digestion of PET-, PTFE-, polyamide- and elastane- containing textiles resulting in a complete release of metallic contents in order to analyze their elemental contents by ICP techniques.

In light of the recent Supreme Court decision to overturn Roe v. Wade, millions of people with uteruses have been forced to navigate precarious access to reproductive care. Although health service psychologists have an ethical responsibility to engage in reproductive justice advocacy, training programs often do not adequately address sexual and reproductive health. Therefore, we sought to better understand how health service psychologists’ personal and professional experiences influence each other and explore the ways in which we as reproductive beings and advocates sustain ourselves amidst tremendous sociopolitical uncertainty. In order to do so, we employed a feminist collaborative autoethnography approach grounded in critical theory. Attending to intersectional identities that help shape diverse expectations and experiences, two early career psychologists and four trainees uncovered 12 domains: barriers in academia; reproductive (dis)empowerment; relational connection; power(lessness) associated with social locations; internalization of sex-negative messages; the influence of sociopolitical climate; burdens related to reproductive rights; evaluations of reproductive justice efforts; component of professional identity; expectations from family and community; overwhelming and exhausting advocacy; and fears of inadequacy. We conclude with limitations and implications for the continued promotion of advocacy through practice and training within and beyond the field of psychology.

Nanocrystalline Cr50Ni50 material was obtained by high-energy ball milling from pure Cr and Ni powders in a planetary ball-mill P7 under argon atmosphere at ambient temperature. Microstructural, structural, morphological, magnetic, and densification properties were studied by X-ray diffraction, scanning electron microscopy, magnetic measurements, and cold compaction followed by sintering. The Rietveld refinement of the X-ray diffraction pattern reveals after 1 h of milling the formation of the disordered fcc-Ni (Cr) solid solution in addition to pure Cr and Ni. After 25 h of milling, the interdiffusion between Cr and Ni atoms leads to the formation of a mixture of disordered fcc-Ni(Cr) and bcc-Cr(Ni) solid solutions. The average thickness of the grain boundaries of bcc-Cr(Ni) and fcc-Ni(Cr) is of about 3.5 and 2.3 nm, respectively. The morphological observations reveal the fragile aspect of the powder particles which is explained by their fragmentation at different stages of the milling process. The existence of small magnetic particles which are typically single domains is evidenced by Mr/Ms (0.1–0.5) values. The porosity fraction of the cold compacted powders is about 25% then decreases to about 12% after sintering at 1250 °C for 2 h. The Vickers microhardness values of the milled powders for 25 h evolute from 1045 to 1280 Hv while those of the sintered powders vary in the range 716 to 995 Hv.

The HEMVACO study evaluated the humoral response after mRNA anti-SARS-CoV-2 vaccination in an hematological cohort.HEMVACO was a prospective, multicentric study registered in ClinicalTrials.gov, number NCT04852796. Patients received two or three doses of BNT162b2 vaccine or mRNA-1273 vaccine. The SARS-CoV-2 TrimericS IgG titers were measured 1, 3, 6 and 12 months after the second dose.Only 16 patients (11.6%) were naive of hematological treatment and 77 patients (55.8%) were on active treatment for hemopathy. Among the 138 analyzed patients, positive antibody titer at 1 month was obtained in 68.1% of patients with mean serology at 850±883 BAU/ml. Risk factors for vaccine failure were anti-CD20 therapy (OR=111[14.3-873]; P0.001), hypogammaglobulinemia under 8g/L (OR=2.49[1.05-5.92]; P=0.032) and lymphopenia under 1.5G/L (OR=2.47[1.18-5.17]; P=0.015). Anti-CD20 therapy induced no anti-SARS-CoV-2 seroconversion (96%). Seventy-eight patients (56.5%) received a third dose and could reach the SARS-CoV-2 TrimericS IgG titer of high-risk patients (P=0.54). The median titer at 379 BAU/ml distinguished two groups of vaccine response (99±121 BAU/ml versus 1,109±678 BAU/ml).Vaccination should be performed before anti-CD20 therapy if the hemopathy treatment can be delayed. Administration of the third vaccine dose was interesting for patients with suboptimal response, defined by a 379 BAU/ml titer in our study.

Introduction: PAH is a severe and rare cardiopulmonary disease which is defined by an elevation of the mean pulmonary artery pressure >25mmHg. ABCC9 mutations are responsible of Cantu syndrome, a disease characterised by several cardiac disorders and for some case pulmonary hypertension (PH). ABCC9 gene encodes for SUR2 protein, a regulatory subunit of KATP channels. KATP are composed of SUR1 or SUR2 and Kir6.1 or Kir6.2 subunits. We hypothesized that SUR2 / Kir6.1 channel contributes to PAH pathogenesis and could be a therapeutic target against PAH. Methods: Using a combination of in vitro , ex vivo and in vivo approaches, we analysed the localisation and expression of SUR2A, SUR2B and Kir6.1 in pulmonary vasculature from control and PAH patients as well as in experimental PH rat-models. We also analysed the role of SUR2/Kir6.1 in PAH physiopathology (PASMCs proliferation, migration and contraction). Finally, we deciphered the consequences of in vivo pharmacological activation of SUR2/Kir6.1 in experimental model of PH. Results: We demonstrated that SUR2A, SUR2B and Kir6.1 are expressed (mRNA and protein) in lungs from control and PAH patients and in MCT induced-PH model.Myograph experiments demonstrated that pharmacological activation of SUR2 by pinacidil induced pulmonary arterial relaxation in human and rat isolated pulmonary arteries. PA relaxation was still present in PA from MCT-rats but reduced compared to control rats. In vitro experiments on human PASMCs (hPASMCs) from control and PAH patients show a decrease of the cell proliferation and migration after SUR2 activation (pinacidil). Using Patch-clamp technique, we demonstrated that SUR2 activator (pinacidil) in adult rat RV cardiomyocytes reduces RV action potential. Finally, pharmacological activation in vivo of SUR2 by pinacidil (1mg/kg/day) on MCT induced-PH rats show an improvement of the hemodynamic parameters as the mean right ventricular systolic pressure during preventive and curative protocol. Conclusions: We demonstrated that SUR2A, SUR2B and Kir6.1 are expressed in hPASMCs and hPECs from control and iPAH patients. The in vivo SUR2 activation by pinacidil treatment reduced MCT induced-PH phenotype suggesting that SUR2 pharmacological activation should be considered for PAH.

People with Intellectual disability consistently appear to be one of the most looked-down upon and repressed subgroups of society in many cultures. The main aim of this study was to compare social representations of intellectual disability in its various aspects between different cultures.The study was conducted in four different sites: Beirut-Lebanon, Algiers-Algeria, Tours-France and Namur-Belgium. Participants were asked to complete a questionnaire evaluating social representations of intellectual disability.A total of 755 participants consented to take part in the study. Gender only affected social representations in the Lebanese population. Overall, Algerians appeared to have the least positive social representations and Lebanon to have more positive attitudes, while France and Belgium tended to have the most favourable representations.Findings highlight the imbalance between a European and a non-European country showing the importance of developing tailored interventions to improve general attitudes towards intellectual disability.

We investigate the performances of two slot-waveguide modulator designs using optical and electrical simulations. The proposed designs utilize high confinement Si slot waveguides in combination with LiNbO 3 (LN). This allows for efficient modulation due to the strong Pockels effect of the LN and the strong electric field of the slot-waveguide.

In this contribution, we aim to modify the photochromic properties of anils using a crystal engineering approach. Previous work has shown cocrystallization to alter the photochromic behavior of anils. Here, a full screening of 15 anil derivatives (including 8 newly described anils) with 21 coformers (carboxylic acids, amides, and halogenated benzene derivatives) was performed, resulting in 89 new anil cocrystals. This large amount of results allows drawing statistically valid insights on the complex photochromic mechanism providing evidence of a continuous phenomenon instead of the classic binary photochromic/nonphotochromic one. This is supported by the discovery of “weakly photochromic compounds” presented in this contribution. All the results allowed confirming that an enol-imine character is a requirement and that reducing the amount of short contacts involving the moieties of interest is an interesting way to fine-tune properties as this acts on both electronic and structural aspects. Following this “continuous hypothesis”, the role of the dihedral angle has been explored and shown to be related to the intensity of photochromism instead of being determinant for its occurrence. In addition, in this contribution, we present a novel way of interpreting DRS (diffuse reflectance spectroscopy) data.

Climate change has been linked with the establishment and geographical expansion of zoonotic diseases, an example of which is the well-documented increase in human cases of Lyme disease in Quebec, Canada. As temperatures continue to increase in Quebec, it is anticipated that several zoonotic diseases will be affected. In response to the growing zoonotic issues facing public health authorities, Quebec’s Multi-Party Observatory on Zoonoses and Adaptation to Climate Change (Observatoire multipartite québécois sur les zoonoses et l’adaptation aux changements climatiques) (the Observatory) was founded in 2015 as part of the Quebec government’s Climate Change Action Plan (Plan d’action 2013–2020 sur les changements climatiques). The Observatory was designed to bring together agencies involved in formulating public policy and experts from the disciplines of human health, animal health and environmental sciences, in a manner similar to the innovative “One World, One Health” approach. The Observatory provides a platform for knowledge sharing and consensus building among representatives of public policy decision makers and scientists. Its main objectives are to anticipate and prioritize potential issues associated with zoonotic diseases in Quebec, in order to support applicable risk management and climate change adaptation. This article describes what the Observatory is, what it does and outlines its plans for the future.

Introduction Trois vagues ont été observées dans le cadre de la pandémie d’infection à SARS-CoV-2 (Covid-19). L’objectif principal était de comparer les patients admis pour Covid-19 grave, en réanimation ou en unité de soins intensif (USI), durant les 2 premières vagues (V1: février 2020 à août 2020 et V2: septembre 2020 à janvier 2021). L’objectif secondaire était d’évaluer les facteurs de risque de mortalité. Méthodes Étude observationnelle, rétrospective, monocentrique (CHU Amiens-Picardie). De février 2020 à janvier 2021, les patients admis en réanimation ou USI pour Covid-19 confirmé (PCR ou test antigénique positif) ou probable (atteinte scannographique et/ou clinique compatible et contexte de contage) étaient inclus. Les données démographiques, biologiques, scannographiques ainsi que les données sur la prise en charge, les complications et la mortalité ont été analysées. Résultats Les patients des 2 périodes (V1: 145 et V2: 120) étaient globalement comparables à l’admission en dehors de leur âge, plus élevé durant V2. La prise en charge a considérablement évolué entre les deux périodes: durant V2, une corticothérapie précoce était plus fréquemment administrée (88,3% vs. 18,8%; p 200 mmHg à l’admission (0,48 [0,26–0,89]; p = 0,019) était associé à un meilleur pronostic. Conclusion Il s’agit de la deuxième étude s’intéressant à la comparaison des patients admis en réanimation en France entre les deux premières vagues de la pandémie. Malgré l’évolution majeure des pratiques, on observe une augmentation de la mortalité en réanimation durant la 2e vague. Le recours plus fréquent à l’OHD n’est pas associé à l’augmentation de la mortalité globale et permet au contraire une diminution de la durée d’hospitalisation, et ainsi une meilleure disponibilité des places de réanimation.

Resume Le succes d’une thrombectomie mecanique, traitement de reference des accidents ischemiques cerebraux par l’occlusion arterielle proximale de la circulation anterieure, est evalue sur un faisceau d’argument clinicoradiologique et par l’absence de complications. Le score modified Thrombolysis In Cerebral Infarction (mTICI) evalue le degre de reperfusion anterograde du territoire sylvien. Cote de 0 a 3, un score mTICI ≥ 2b etait considere comme un succes angiographique dans les recents essais, en faisant un facteur pronostic majeur. Une reperfusion mTICI ≥ 2b est naturellement associe a une recuperation clinique, evalue par le score National Institutes of Health Stroke Scale a la phase aigue. Le niveau de dependance est evalue a 90 jours par le score de Rankin modifie (mRS). L’evolution clinique est consideree comme favorable lorsque le mRS est inferieur a 2, correspondant a une autonomie dans les activites de la vie quotidienne. De recents travaux suggerent qu’un score mTICI ≥ 2c serait un meilleur indicateur d’evolution clinique favorable a 3 mois. Les complications hemorragiques ont lieu principalement dans les premieres heures de la reperfusion et sont liees a la transformation hemorragique du territoire ischemique, les complications par perforation arterielle etant plus rares. La migration d’un thrombus au niveau de l’artere cerebrale anterieure est la principale complication procedurale.

The objective of this study was to determine if increasing forage botanical diversity improved stocker gains on warm-season annual (WSA) pastures. An opportunity exists to add extra gain on fall-born calves by grazing summer pastures after spring weaning and selling at a more favorable late summer market. However, cool-season perennial pastures in the Mid-South often have insufficient quality and yield to support desired summer gains. Therefore, the improved production and nutritive value of WSA forages shows promise in this system. A study was conducted near Princeton, KY, where calves (329, 366, and 297 kg in 2017, 2018, and 2019, respectively) grazed one of three WSA forage treatments without supplementation in a randomized complete block design with three replications. Treatments included 1) sorghum-sudangrass monoculture (MONO), 2) simple mixture (SIMPLE = sorghum-sudangrass, pearl millet, soybean), and 3) complex mixture (COMPLEX = SIMPLE + sudangrass, corn, crabgrass, cowpea, sunflower, sunn hemp, daikon radish, forage rape, Korean lespedeza). In 2017, MONO and SIMPLE calves had higher average daily gain (ADG) than COMPLEX calves (0.79 kg/day vs. 0.66 kg/day, P < 0.03). In 2018, no differences in ADG were detected among treatments (P > 0.3); however, calves only gained 0.01 kg/day. In 2019, MONO and SIMPLE calves again had higher ADG than COMPLEX calves (0.59 kg/day vs. 0.43 kg/day, P < 0.03). The exceptionally low 2018 ADG was likely due to the higher nutritional demand of heavier calves and the lower nutritive value of mature forages compared to other years. In conclusion, complex WSA forage mixtures did not offer any improvement in animal performance, and proper management of all WSA forages (maintaining a vegetative state) is paramount to achieving adequate gains on stockers without supplementation; however, supplementation may be necessary to improve WSA forage utilization in the rumen, potentially leading to more favorable gains.

Nanostructuring for the purpose of reflectance reduction has been widely investigated for Silicon based solar applications. Bare Silicon surfaces reflect between 50 and 60 % of the incident light and are thus unsuitable for absorbing significant amounts of sunlight. A typical approach to addressing this is to use an anti-reflective coating on top of the Silicon which reduces reflectance via destructive interference. Since this interference is mainly dependent on the thickness of film this type of anti-reflection layer can only be optimized for a certain wavelength and thus is inherently limited. To reduce the reflectance over a broad range of wavelengths a structuring based approach is necessary. A common approach to implementing this is by wet etching the top surface of a crystalline solar cell to create pyramid structures based on the crystalline dependence of the etching process. Since this approach exploits the crystalline structure it is most suited for crystalline Si. Dry etching based nanostructuring can offer a high level of control over the resulting structure with the crystalline dependence being less concern. One approach is to etch cylindrical holes arranged in a periodic fashion into the top surface of the device to create a photonic crystal lattice. Here we present a systematic analysis of a photonic crystal slabs in Silicon and how the geometry affect the reflectance of the device. Lumerical’s FDTD solution is used to vary the pitch, diameter and depth of the cylindrical holes making up the Photonic Crystal structure. The analysis reveals that air fill fraction and hole depth are the most significant determinants of the overall reflectance.

In this work, we probe the photodegradative behaviour of CsPbBr3 perovskite nanocrystals under illumination intensities in excess of 1 W=cm2. In doing so, we uncover optical behaviours unique to this extreme form of degradation namely a pronounced period of increasing photoluminescent intensity at the outset of degradation along with a red-shifted emission lobe. We also compare the photochemical lifetimes of CsPbBr3 to the relating organic-inorganic hybrid of FAPbBr3 and show that FAPbBr3 can withstand such high intensities for approximately ten times longer than CsPbBr3. This marks out FAPbBr3 as a potential successor to CsPbBr3 in optoelectronic applications.

LED surface structuring has been widely used to increase light extraction[1]. Due to the high refractive index of the thick GaN epitaxy layers, most emitted light becomes trapped and reabsorbed by the epitaxial layers. While random structuring can effectively scatter trapped light out of the LED, it gives little control over the resulting beam-shapef[2]. Photonic crystals however provide a means to simultaneously improve light extraction efficiency and control beam directionality. Furthermore, P-side up LEDs normally utilize a transparent top contact layer in order to allow top light emission whilst maintaining good electrical properties. In this paper we investigate a novel photonic crystal LED configuration with a nontransparent metal top contact layer, and cylindrical holes etched through the top contact layer and deep into the underlying epitaxy. In this novel configuration light emission is only possible from the etched holes giving rise to extreme beam steering effects. We utilize broadband spectroscopic reflectometry to experimentally investigate beam shape and optical properties from fabricated devices. We observe a range of achievable beam patterns with extreme deviations from the normal Lambertian. We investigate the effect of square and triangular photonic crystal lattices on beam directionality.

Background: Accidental dural puncture is an uncommon complication of epidural analgesia and can cause postdural puncture headache (PDPH). We aimed to describe management practices and outcomes after PDPH treated by epidural blood patch (EBP) or no EBP. Methods: Following ethics committee approval, patients who developed PDPH after accidental dural puncture were recruited from participating countries and divided into two groups, those receiving EBP or no EBP. Data registered included patient and procedure characteristics, headache symptoms and intensity, management practices, and complications. Follow-up was at 3 months. Results: A total of 1001 patients from 24 countries were included, of which 647 (64.6%) received an EBP and 354 (35.4%) did not receive an EBP (no-EBP). Higher initial headache intensity was associated with greater use of EBP, odds ratio 1.29 (95% confidence interval 1.19–1.41) per pain intensity unit increase. Headache intensity declined sharply at 4 h after EBP and 127 (19.3%) patients received a second EBP. On average, no or mild headache (numeric rating score≤3) was observed 7 days after diagnosis. Intracranial bleeding was diagnosed in three patients (0.46%), and backache, headache, and analgesic use were more common at 3 months in the EBP group. Conclusions: Management practices vary between countries, but EBP was more often used in patients with greater initial headache intensity. EBP reduced headache intensity quickly, but about 20% of patients needed a second EBP. After 7 days, most patients had no or mild headache. Backache, headache, and analgesic use were more common at 3 months in patients receiving an EBP. © 2020 British Journal of Anaesthesia

Solar cells based on GaAs often include a wide-bandgap semiconductor as a window layer to improve surface passivation. Such devices often have poor photon-to-electron conversion efficiency at higher photon energies due to parasitic absorption. In this article, we deposit FAPbBr3 perovskite quantum dots on the AlInP window layer of a GaAs thin-film solar cell to improve the external quantum efficiency (EQE) across its entire absorption range, resulting in an 18% relative enhancement of the short-circuit current density. Luminescent downshifting from the quantum dots to the GaAs device contributes to a large effective enhancement of the internal quantum efficiency (IQE) at shorter wavelengths. Additionally, improved surface passivation of the window layer results in a 14–16% broadband increase of the IQE. These mechanisms combined with increased overall photon collection (antireflective effects) results in a doubling of the EQE in the ultraviolet region of the solar spectrum. Our results show a promising application of perovskite nanocrystals to improve the performance of well-established thin-film solar cell technologies.

Introduction Depuis 2019, l’épidémie de COVID-19 (infection à SARS-CoV-2) est responsable de 4 millions de décès dans le monde. Il n’existe, à ce jour, aucun traitement spécifique. La corticothérapie fait partie, depuis octobre 2020, du standard of care, suite à la publication de plusieurs études (dont la cohorte RECOVERY, NEJM 2020) montrant une amélioration significative de la survie lorsqu’elle est utilisée à la phase aiguë des pneumopathies hypoxémiantes. Cependant, peu de données sont disponibles concernant son impact sur l’atteinte résiduelle. Notre étude a donc cherché à savoir si le recours aux corticoïdes à la phase aiguë des infections à SARS-CoV-2 réduit la survenue de séquelles respiratoires à 3 mois, 6 mois et 1 an. Méthodes Il s’agit d’une étude observationnelle, rétrospective, réalisée au CHU d’Amiens entre mars et octobre 2020 concernant les patients ayant été hospitalisés dans une unité COVID. Ces patients étaient convoqués à 3 mois pour la réalisation d’un examen clinique, d’un scanner thoracique, d’explorations fonctionnelles respiratoires et d’un test de marche de 6 minutes. L’évaluation à 6 mois et 12 mois étaient optionnelles. Résultats Trois cent neuf patients ont été inclus. Parmi eux, 74 patients (23,9 %) avaient reçu une corticothérapie. À 3 mois, les patients ayant reçu une corticothérapie présentaient significativement plus de lésions en verre dépoli et une atteinte radiologique plus étendue ; ce qui n’était plus le cas à 6 mois et à 1 an. Il n’y avait pas de différence significative concernant les séquelles fonctionnelles à 3 mois comme sur le plus long terme. Conclusion Les patients ayant reçu une corticothérapie étaient peu nombreux et les plus graves, issus de la « première vague », ce qui peut expliquer les différences retrouvées lors de l’évaluation à 3 mois. Les séquelles respiratoires à 6 mois et 1 an semblent moins importantes dans le groupe ayant reçu une corticothérapie, mais le nombre de patients est insuffisant pour conclure. Cette étude n’a pas permis de mettre en évidence de différence significative à long terme entre les patients ayant reçu ou non une corticothérapie. Il semble nécessaire de poursuivre cette étude en appariant les patients sur la gravité initiale.

Reduction of surface reflection loss is crucial for high efficiency next generation Si solar cells. Surface texturing provides a viable method to reduce loss over the full solar bandwidth. Previous studies have concentrated on simple moth-eye silicon pillar arrays protruding from the surface. Using FDTD simulation methods, we undertake a systematic investigation into performance benefits provided by complex semi-random photonic quasi-crystal surface patterning methodologies whereby arrays of air holes are etched deep into the solar cell surface. In contrast to other studies we carefully investigate the effect of lattice symmetry, systematically comparing performance of simple 6-fold symmetric triangular photonic crystal patterning to 12 fold symmetry photonic quasicrystal patterning and infinitely symmetric 2D Fibonacci patterning. We optimize key geometric parameters such as lattice pitch, hole size and etch depth to maximize optical performance for each lattice type. 12 fold photonic quasi crystal lattice is found to provide best overall anti-reflectance performance providing a solar-corrected average reflectance of 8.3% for a hole depth of 1.5 µm and 300 nm diameter, in comparison to 36.4% for a bare silicon solar cell surface. Practical feasibility of the optimal designs is demonstrated by fabrication of physical prototypes consisting of arrays of nm scale air-holes etched into the surface of a silicon slab fabricated Using e-beam lithography and ICP/RIE etching. FDTD Simulation methodology is validated by convergence studies as well as comparison to optical measurements on these fabricated devices. Furthermore, in contrast to previous studies we provide an in depth analysis of the physical mechanisms responsible for reduction in surface reflection, determining the parameter space where conventional Gaussian optical processes such as effective refractive index, refraction and Fresnel reflection dominate, vs parameter space where sub wavelength photonic crystal scattering effects play the main role. We finish up with an analysis of electrical performance for the optimal designs to further validate real world performance. Taking electrical performance into account we determine that infinite-symmetry 2D Fibonacci patterning far outperforms lower symmetry 12 fold and triangular arrangement. We believe that this is the first in depth investigation into 2D Fibonacci patterning in silicon solar cells.

Resume Introduction Cette derniere decennie a vu le nombre d’arthroscopies iteratives augmenter avec l’expansion de cette technique. Mais le resultat et les causes de ces procedures de revision ne sont pas connus avec precision. Aussi nous avons mene une etude prospective afin de connaitre : 1) les resultats fonctionnels et la satisfaction des patients apres arthroscopie iterative, 2) les indications de ces interventions. Hypothese Notre hypothese etait l’amelioration des scores fonctionnels et de la satisfaction des patients operes. Materiels et methode Il s’agit d’une etude prospective continue, monocentrique, sans groupe temoin incluant des patients ayant beneficie d’une arthroscopie iterative de hanche entre septembre 2010 et septembre 2014 et revus au recul moyen de 28 mois (mediane 23,3 ; 12 a 62 mois). L’evaluation fonctionnelle des patients se faisait en preoperatoire et a la revision par les questionnaires de Harris modifie, de WOMAC et de Christensen (NHAS) ; completee par une echelle de satisfaction. Apres bilan etiologique, l’arthroscopie iterative etait jugee possible par la mise en evidence d’une cause expliquant la recidive ou persistance des douleurs et accessible a un traitement sous arthroscopie. Resultats Il s’agissait de 17 patients sur 295 arthroscopies primaires (5,7 %) comportant 9 hommes et 8 femmes, d’âge median 29,6 ans (16 a 48 ans). L’indication des arthroscopies initiales comportait 13 conflits femoro-acetabulaires, 3 lesions du labrum sur instabilite, 1 chondromatose et 1 arthrose. Au total, 11 lesions sur les 17 decrites initialement persistaient dont 9/13 concernant les conflits femoro-acetabulaire. Trois echecs sur les 17 arthroscopies iteratives ont ete rapportes. Tous les scores fonctionnels ont ete ameliores avec un gain de 7 points (p Conclusion Bien que moins bon que dans les arthroscopies de premiere intention, les resultats fonctionnels apres arthroscopie iterative de hanche restent satisfaisants a court terme. La cause principale de reprise arthroscopique est la persistance des anomalies initiales par insuffisance de traitement. Niveau de preuve IV prospectif.

The rate of iterative arthroscopy has been increasing over the last decade as the technique has grown. The results of and reasons for these revision procedures, however, are not exactly known. We therefore conducted a prospective study to shed light on: 1) functional results and patient satisfaction following repeated arthroscopy, and 2) the relevant indications.Functional scores and patient satisfaction increase following repeated arthroscopy. MATERIALS AND METHOD: A single-center continuous prospective study without control group included patients undergoing repeated hip arthroscopy between September 2010 and September 2014, with a mean 28months' follow-up (median, 23.3months; range, 12-62months). Preoperative and follow-up functional assessment used the modified Harris hip, WOMAC and Christensen (NHAS) questionnaires, and a satisfaction scale. On etiological analysis, repeated arthroscopy was indicated if a cause of recurrent or persistent pain accessible to arthroscopic treatment was identified.Seventeen patients were included out of 295 primary arthroscopies (5.7%): 9 male, 8 female; median age, 29.6years (range, 16-48years). Indications for primary arthroscopy comprised 13 cases of femoroacetabular impingement, 3 labrum lesions with instability, 1 chondromatosis and 1 case of osteoarthritis. Eleven of the 17 primary lesions showed persistence, including 9 of the 13 cases of femoroacetabular impingement. There were 3 failures in 17 repeated arthroscopies. All functional scores improved, with a gain of 7 points (P0.06) on modified Harris hip score, 25 points (P0.0006) on WOMAC score, and 27 points (P0.001) on NHAS score. Ten of the 17 patients were satisfied or very satisfied with the repeated arthroscopy (59%).Although less good than on primary arthroscopy, functional results on repeated hip arthroscopy were satisfactory in the short term. The main reason for repeated arthroscopy was persistence of initial abnormality due to insufficient treatment.