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1.
Artículo en Inglés | MEDLINE | ID: mdl-38943431

RESUMEN

Acne is a common skin condition, but little data exist on the comparative efficacy of topical acne therapies. We conducted a systematic review and network meta-analysis to evaluate the efficacy of topical therapies for mild-to-moderate acne. Searches in PubMed/MEDLINE, Cochrane CENTRAL via Ovid, Embase via Ovid and Web of Science were conducted on 29 November 2021. Randomized controlled trials examining ≥12 weeks of topical treatments for acne vulgaris in subjects aged 12 and older were included. Main outcomes were absolute or percent change in acne lesion count and treatment success on the Investigator's Global Assessment scale. Thirty-five randomized clinical trials with 33,472 participants comparing nine different topical agents were included. Adapalene-benzoyl peroxide (BPO), clindamycin-BPO and clindamycin-tretinoin demonstrated the greatest reduction in non-inflammatory (ratio of means [RoM] 1.76; 95% CI [1.46; 2.12], RoM 1.70; 95% CI [1.44; 2.02] and RoM 1.87; 95% CI [1.53; 2.30], respectively), inflammatory (RoM 1.56; 95% CI [1.44; 1.70], RoM 1.49; 95% CI [1.39; 1.60] and RoM 1.48; 95% CI [1.36; 1.61], respectively) and total lesion count (ROM 1.67; 95% CI [1.47; 1.90], RoM 1.59; 95% CI [1.42; 1.79] and RoM 1.64; 95% CI [1.42; 1.89], respectively) compared to placebo. All single agents outperformed placebo except tazarotene, which did not significantly outperform placebo for inflammatory and non-inflammatory lesion count reduction. Most combination agents significantly outperformed their individual components in lesion count reduction and global assessment scores, except for clindamycin-tretinoin and clindamycin-BPO, which did not significantly outperform tretinoin (RoM 1.13; 95% CI [0.94; 1.36]) and BPO (RoM = 1.15, 95% CI [0.98; 1.36]), respectively, for non-inflammatory lesion reduction. There was no significant difference amongst most single agents when evaluating lesion count reduction. Combination agents are generally most effective for mild-to-moderate acne; however for non-inflammatory acne, the addition of clindamycin in topical regimens is unnecessary and should be avoided.

3.
Acad Pediatr ; 21(8): 1318-1327, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34280477

RESUMEN

BACKGROUND: Primary care providers (PCPs), including pediatricians and general practitioners, are often the first to see children with eczema/atopic dermatitis (AD). Little is known about management of pediatric AD by PCPs and adherence to national guidelines. OBJECTIVE: To review existing literature examining management components of pediatric AD (topical corticosteroids [TCS], topical calcineurin inhibitors [TCIs], antihistamines, bathing, emollients, and diet) by PCPs. DATA SOURCES: PubMed/Medline and Embase. STUDY ELIGIBILITY CRITERIA: English-language articles dated 2015 to 2020 reporting outcomes addressing management of pediatric AD by PCPs. STUDY APPRAISAL AND SYNTHESIS METHODS: Two authors independently screened titles/abstracts, reviewed full-text articles, extracted relevant data, and evaluated study quality. Disagreements were resolved by a third author. RESULTS: Twenty articles were included. Surveys and national database analyses were the most common methodologies (n = 7 each). PCPs commonly prescribed TCS but had a preference for low-potency agents, overprescribed nonsedating antihistamines, and avoided TCIs. PCPs commonly recommended emollients, although this was not universal. Data characterizing nonmedication management were limited. LIMITATIONS: Most studies did not examine individual patient encounters, but rather relied on providers reporting their general behaviors. Provider behavior may vary based on country of practice. CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS: Knowledge and management gaps exist among PCPs in treating pediatric AD in key areas including knowledge of TCS safety profiles and prescribing of TCIs. The current literature is largely limited to small studies that evaluate prescribing behaviors with limited data characterizing nonmedication management, highlighting the need for future research in this area.


Asunto(s)
Dermatitis Atópica , Eccema , Inhibidores de la Calcineurina , Niño , Dermatitis Atópica/tratamiento farmacológico , Emolientes/uso terapéutico , Humanos , Atención Primaria de Salud
4.
Curr Opin Pediatr ; 33(4): 373-379, 2021 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-34101705

RESUMEN

PURPOSE OF REVIEW: Photograph-based social media use among children and adolescents has skyrocketed over the past decade, raising concerns about the implications for self-confidence and behavior in this population. Social media 'challenges' encourage participants to complete potentially dangerous tasks while sharing their completion of the tasks on social media. Many of these challenges affect the skin and lead to recognizable findings on physical examination. This review discusses the history of prominent social media challenges and their effects on the skin. Attention is also given to the effects of social media trends on self-confidence and body image in children and adolescents. RECENT FINDINGS: Over the past several years, there have been several notable social media trends that can harm the skin. These include the Kylie Jenner lip challenge, salt and ice challenge, deodorant challenge, eraser challenge, fire challenge, and hot water challenge. Participation in these challenges can cause morbidity in children and adolescent that should be recognized by clinicians. SUMMARY: Social media has become an important platform for communication and self-expression among children and adolescents. Pediatricians should remain aware of social trends in this age group and look out for cutaneous findings that may signal dangerous behavior on social media.


Asunto(s)
Conducta del Adolescente , Enfermedades de la Piel , Medios de Comunicación Sociales , Adolescente , Niño , Humanos , Polisorbatos , Piel , Enfermedades de la Piel/diagnóstico , Enfermedades de la Piel/epidemiología
5.
Pediatr Dermatol ; 38(5): 1127-1131, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33870556

RESUMEN

BACKGROUND/OBJECTIVES: To investigate the evaluation and management of atopic dermatitis (AD) in the pediatric emergency department (PED). METHODS: This retrospective chart review was performed at the PED of a single institution and examined data from 2012 to 2017. Of 335 visits from patients 18 years and younger coded for AD, 167 visits with documented findings that supported a diagnosis of AD according to guidelines from the American Academy of Dermatology were included. RESULTS: The mean age of presentation was 6.3 years (standard deviation [SD]: 5.9). Of 11 patients with multiple visits, the mean between-visit interval was 31 days (SD: 41). Topical corticosteroids (TCSs) were not prescribed or recommended in 63/167 visits. In an additional 46/167 visits, over-the-counter topical hydrocortisone was recommended. Of prescribed TCS, the mean TCS class was 5.5 (SD: 1.9). 61/104 recommended or prescribed TCSs were weak (Class 7), the most likely used class (P < .001). Dermatology consultation was requested in 14/167 visits and was associated with higher rates of TCS prescriptions (13/14 vs 91/153, P = .018), a higher mean class of TCS prescribed (3.1 vs 5.9, P < .001), higher prescription rates of systemic antibiotics (8/14 vs 10/153, P < .001), and higher recommendation rates for emollient usage (10/14 vs 46/153, P = .005). CONCLUSIONS: Most patients presenting to the PED for AD were either not prescribed a TCS or were prescribed a weak TCS, often one that is over-the-counter. While there may be a variety of explanations for these findings, it is possible they reveal a practice gap regarding AD management in the PED.


Asunto(s)
Dermatitis Atópica , Corticoesteroides/uso terapéutico , Niño , Dermatitis Atópica/tratamiento farmacológico , Servicio de Urgencia en Hospital , Emolientes/uso terapéutico , Humanos , Estudios Retrospectivos
6.
JAMA Dermatol ; 157(2): 207-212, 2021 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-33295957

RESUMEN

Importance: To date, no study has characterized the mucocutaneous features seen in hospitalized children with multisystem inflammatory syndrome in children (MIS-C) or the temporal association of these findings with the onset of systemic symptoms. Objective: To describe the mucocutaneous findings seen in children with MIS-C during the height of the coronavirus disease 2019 (COVID-19) pandemic in New York City in 2020. Design, Setting, and Participants: A retrospective case series was conducted of 35 children admitted to 2 hospitals in New York City between April 1 and July 14, 2020, who met Centers for Disease Control and Prevention and/or epidemiologic criteria for MIS-C. Main Outcomes and Measures: Laboratory and clinical characteristics, with emphasis on mucocutaneous findings, of children who met criteria for MIS-C. The characterization of mucocutaneous features was verified by 2 board-certified pediatric dermatologists. Results: Twenty-five children (11 girls [44%]; median age, 3 years [range, 0.7-17 years]) were identified who met definitional criteria for MIS-C; an additional 10 children (5 girls [50%]; median age, 1.7 years [range, 0.2-15 years]) were included as probable MIS-C cases (patients met all criteria with the exception of laboratory test evidence of severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] infection or known exposure). The results of polymerase chain reaction tests for SARS-CoV-2 were positive for 10 patients (29%), and the results of SARS-CoV-2 immunoglobulin G tests were positive for 19 patients (54%). Of the 35 patients, 29 (83%) exhibited mucocutaneous changes, with conjunctival injection (n = 21), palmoplantar erythema (n = 18), lip hyperemia (n = 17), periorbital erythema and edema (n = 7), strawberry tongue (n = 8), and malar erythema (n = 6) being the most common findings. Recognition of mucocutaneous findings occurred a mean of 2.7 days (range, 1-7 days) after the onset of fever. The duration of mucocutaneous findings varied from hours to days (median duration, 5 days [range, 0-11 days]). Neither the presence nor absence of mucocutaneous findings was significantly associated with overall disease severity. Conclusions and Relevance: In this case series of hospitalized children with suspected MIS-C during the COVID-19 pandemic, a wide spectrum of mucocutaneous findings was identified. Despite their protean and transient nature, these mucocutaneous features serve as important clues in the recognition of MIS-C.


Asunto(s)
COVID-19/complicaciones , Enfermedades de la Piel/etiología , Síndrome de Respuesta Inflamatoria Sistémica/complicaciones , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Membrana Mucosa , Ciudad de Nueva York , Estudios Retrospectivos
7.
Comput Methods Biomech Biomed Engin ; 24(1): 21-32, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32840119

RESUMEN

The NFL recently released validated helmet-impact models to study the performance of currently used helmets. This study used the model of a Riddell Speed Classic helmet to determine the influence of the properties of protective foam padding on acceleration and deformation at two common impact locations to cause concussions. The performance of the helmet was measured before and after manipulating the material properties of the protective foam liner material using FEA software. The densification strain was adjusted by using the scale factor tool in LS-DYNA to create four material categories - soft, standard, stiff, and rigid. The helmet was tested under side and rear impacts using the four material properties at 2.0, 5.5, 7.4, 9.3 and 12.3 m/s impact speeds using the NOCSAE linear impactor model. This study suggests that the standard foam material compresses to a range that could be considered to have "bottomed out" at impact speeds at 5.5 m/s for side impacts. Despite testing a wide range of material properties, the measured accelerations did not vary dramatically across material properties. Rather, impact speed played the dominant role on measured acceleration. This is the first study to demonstrate how open-source impact models can be used to run a design of experiments and investigate the role between different materials used inside a helmet and football helmet performance.


Asunto(s)
Simulación por Computador , Fútbol Americano , Dispositivos de Protección de la Cabeza , Aceleración , Fenómenos Biomecánicos , Cabeza , Humanos , Modelos Anatómicos
8.
Pediatr Dermatol ; 38(1): 45-49, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32767593

RESUMEN

BACKGROUND/OBJECTIVE: Papular scars are a recently described clinical phenotype of acne scarring characterized by papules occurring on the nose and chin. We have observed a similar presentation of nasal papules among patients seen in our clinic for acne and sought to further characterize the clinical and histopathological characteristics of this entity. METHODS: In this single-site case series, a retrospective review of electronic medical records of patients with nasal papules in association with acne vulgaris between April 2018 and April 2019 was performed. Clinical and histopathologic findings were recorded. RESULTS: We identified 20 patients who presented with a similar clinical phenotype of predominantly skin-colored, dome-shaped papules concentrated on the nose and chin in association with a history of more classic facial acne vulgaris. Papular lesions were seen predominately in adolescent Hispanic males. Concomitant acne on other areas of the face was identified in 18 patients at presentation while two patients had a history of adolescent acne. Biopsies were performed for five patients. Histopathologic examination demonstrated features of fibrosis and dilated thin-walled blood vessels, typical of angiofibromas. CONCLUSION: We present a series of adolescent patients with large, flesh-colored to erythematous papules seen predominantly on the nose. These lesions are histologically indistinguishable from angiofibromas and may represent an under-recognized yet disfiguring sequela of acne that may disproportionately affect adolescents with skin of color.


Asunto(s)
Acné Vulgar , Angiofibroma , Acné Vulgar/diagnóstico , Adolescente , Angiofibroma/diagnóstico , Humanos , Masculino , Nariz , Estudios Retrospectivos , Piel
9.
Pediatr Dermatol ; 37(6): 1185-1186, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32869334

RESUMEN

BRAF inhibitor-induced neutrophilic panniculitis is a rare event that is well-characterized in adults undergoing therapy for metastatic melanoma. To date, there are very few reports of this event in children undergoing BRAF inhibitor therapy for low-grade gliomas, all of which were seen with vemurafenib. We report a case of dabrafenib-induced neutrophilic panniculitis in a 9-year-old girl that manifested within several weeks of initiating dual BRAF-MEK inhibitor therapy for glioblastoma multiforme. This case highlights neutrophilic panniculitis as a side effect of dabrafenib in children and serves as a reminder to consider cutaneous side effects of BRAF inhibitors as they are increasingly used to treat children with primary brain tumors.


Asunto(s)
Glioblastoma , Paniculitis , Neoplasias Cutáneas , Protocolos de Quimioterapia Combinada Antineoplásica , Niño , Femenino , Glioblastoma/tratamiento farmacológico , Humanos , Imidazoles , Quinasas de Proteína Quinasa Activadas por Mitógenos/uso terapéutico , Oximas/efectos adversos , Paniculitis/inducido químicamente , Paniculitis/diagnóstico , Inhibidores de Proteínas Quinasas/efectos adversos , Proteínas Proto-Oncogénicas B-raf/genética , Piridonas/uso terapéutico , Neoplasias Cutáneas/tratamiento farmacológico
10.
Pediatr Dermatol ; 37(5): 993-995, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32662137

RESUMEN

Photograph editing has been present for centuries, but the past decade has seen an unprecedented rise in the practice, particularly on social media platforms. Common filters are able to soften complexion, remove blemishes, and even reshape facial features. Children and adolescents with skin conditions may find solace in using these applications to mask their disease online, but there is increasing concern about negative overall body image among those who filter their photographs. Pediatric dermatologists should remain aware of the practice of photograph editing among young people and consider asking patients about their social media presence.


Asunto(s)
Enfermedades de la Piel , Adolescente , Niño , Dedos , Humanos , Piel , Medios de Comunicación Sociales
12.
Science ; 368(6497)2020 06 19.
Artículo en Inglés | MEDLINE | ID: mdl-32439657

RESUMEN

Although perovskite solar cells have produced remarkable energy conversion efficiencies, they cannot become commercially viable without improvements in durability. We used gas chromatography-mass spectrometry (GC-MS) to reveal signature volatile products of the decomposition of organic hybrid perovskites under thermal stress. In addition, we were able to use GC-MS to confirm that a low-cost polymer/glass stack encapsulation is effective in suppressing such outgassing. Using such an encapsulation scheme, we produced multi-cation, multi-halide perovskite solar cells containing methylammonium that exceed the requirements of the International Electrotechnical Commission 61215:2016 standard by surviving more than 1800 hours of the Damp Heat test and 75 cycles of the Humidity Freeze test.

13.
Urology ; 142: 14-21, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32320789

RESUMEN

There are a number of dermatoses that manifest in the genital region. Urologists are often the first point of contact for patients with such disorders. These can be isolated genital conditions or manifestations of a more widespread cutaneous disease. Though similar appearing, there are often key clinical findings that aid in in diagnosis. In general, genital dermatoses can be classified as physiologic variants, inflammatory, neoplastic, or infectious in etiology. This article provides a broad overview for urologists in addressing both common and rarer penile and scrotal dermatoses. Emphasis is placed on characteristic clinical findings to aid in diagnosis. Recommendations for diagnostic evaluation, treatment, and appropriate follow-up are discussed.


Asunto(s)
Enfermedades del Pene , Escroto , Enfermedades de la Piel , Humanos , Masculino , Enfermedades del Pene/diagnóstico , Enfermedades del Pene/terapia , Enfermedades de la Piel/diagnóstico , Enfermedades de la Piel/terapia
14.
Pediatr Ann ; 49(3): e116-e123, 2020 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-32155277

RESUMEN

Childhood exanthems are commonly encountered by pediatricians in the hospital and the office. In the last several decades, we have seen a shift in the epidemiology of many of these diseases. After being deemed eliminated at the turn of 21st century, measles has experienced a resurgence secondary to falling vaccination rates, raising public health concerns. A new variant of hand, foot, and mouth disease caused by coxsackievirus A6 has been associated with more widespread and atypical disease, which can present diagnostic challenges to clinicians. Parvovirus B19, which is traditionally associated with fifth disease, is also the leading cause of papular purpuric gloves and socks syndrome, a rare condition with which providers may be unfamiliar. Since the introduction of routine vaccination, there has been a shift in the epidemiology and clinical presentation of primary varicella and herpes zoster. Finally, the recently described phenomenon of Mycoplasma pneumoniae-induced rash and mucositis will be discussed. [Pediatr Ann. 2020;49(3):e116-e123.].


Asunto(s)
Exantema , Enfermedad de Boca, Mano y Pie , Neumonía por Mycoplasma , Niño , Exantema/diagnóstico , Exantema/etiología , Exantema/terapia , Dermatosis del Pie , Dermatosis de la Mano , Enfermedad de Boca, Mano y Pie/diagnóstico , Humanos , Neumonía por Mycoplasma/complicaciones
15.
Pediatr Dermatol ; 37(3): 531-533, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32124476

RESUMEN

Infectious panniculitis from hematogenous spread is uncommon and usually occurs in immunocompromised patients. Dissemination of gram-positive organisms to the subcutaneous tissue is rare with only several reports of disseminated panniculitis caused by Streptococcal species. We report a case of an immunocompetent 2-year-old boy presenting with diffuse neutrophilic panniculitis arising from methicillin-resistant Staphylococcus aureus septicemia. This case represents a highly atypical manifestation of severe MRSA infection and serves as a reminder to consider MRSA as a cause of disseminated neutrophilic panniculitis, particularly in high-risk populations.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Paniculitis , Enfermedades Cutáneas Infecciosas , Infecciones Estafilocócicas , Antibacterianos , Preescolar , Humanos , Huésped Inmunocomprometido , Masculino , Infecciones Estafilocócicas/diagnóstico , Infecciones Estafilocócicas/tratamiento farmacológico
16.
Radiology ; 293(2): 282-291, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31526252

RESUMEN

Background Male breast cancer incidence is rising. There may be a potential role in selective screening in men at elevated risk for breast cancer, but the effectiveness of such screening remains unexplored. Purpose To evaluate patterns of male breast imaging utilization, to determine high-risk screening outcomes, and to delineate risk factors associated with cancer diagnosis. Materials and Methods This retrospective study reviewed consecutive male breast imaging examinations over a 12-year period (between 2005-2017). Examination indications, biopsy recommendations, and pathologic results were correlated with patient characteristics. Fisher exact test, Mann-Whitney test, Spearman correlation, and logistic regression were used for statistical analysis. Results A total of 1869 men (median age, 55 years; range, 18-96 years) underwent 2052 examinations yielding 2304 breast lesions and resulting in 149 (6.5%) biopsies in 133 men; 41 (27.5%) were malignant and 108 (72.5%) were benign. There were 1781 (86.8%) diagnostic and 271 (13.2%) screening examinations. All men undergoing screening had personal or family history of breast cancer and/or genetic mutations. There was a significant increase in the number of examinations in men relative to the number of examinations in women over time (Spearman correlation, r = 0.85; P < .001). Five node-negative cancers resulted from screening mammography, yielding a cancer detection rate of 18 per 1000 examinations (95% confidence interval [CI]: 7, 41), with cancers diagnosed on average after 4 person-years of screening (range, 1-10 person-years). Mammographic screening sensitivity, specificity, and positive predictive value of biopsy were 100% (95% CI: 50%, 100%), 95.0% (95% CI: 93.1%, 98%), and 50% (95% CI: 22.2%, 77.8%). Older age (P < .001), Ashkenazi descent (P < .001), genetic mutations (P = .006), personal history (P < .001), and first-degree family history (P = .03) were associated with breast cancer. Non-first-degree family history was not associated with cancer (P = .09). Conclusion There is potential benefit in screening men at high risk for developing breast cancer. Such screening may have increased over time. © RSNA, 2019.


Asunto(s)
Neoplasias de la Mama Masculina/diagnóstico por imagen , Detección Precoz del Cáncer/métodos , Mamografía/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Biopsia , Neoplasias de la Mama Masculina/etiología , Neoplasias de la Mama Masculina/patología , Detección Precoz del Cáncer/estadística & datos numéricos , Femenino , Humanos , Estudios Longitudinales , Masculino , Mamografía/estadística & datos numéricos , Tamizaje Masivo/métodos , Tamizaje Masivo/estadística & datos numéricos , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Sensibilidad y Especificidad , Adulto Joven
17.
Materials (Basel) ; 10(10)2017 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-28956841

RESUMEN

Rain erosion damage, caused by repeated droplet impact on wind turbine blades, is a major cause for concern, even more so at offshore locations with larger blades and higher tip speeds. Due to the negative economic influence of blade erosion, all wind turbine Original Equipment Manufacturers (OEMs) are actively seeking solutions. In most cases, since the surface coating plays a decisive role in the blade manufacture and overall performance, it has been identified as an area where a solution may be obtained. In this research, two main coating technologies have been considered: In-mould coatings (Gel coating) applied during moulding on the entire blade surface and the post-mould coatings specifically developed for Leading Edge Protection (LEP). The coating adhesion and erosion is affected by the shock waves created by the collapsing water droplets on impact. The stress waves are reflected and transmitted to the laminate substrate, so microstructural discontinuities in coating layers and interfaces play a key role on its degradation and may accelerate erosion by delamination. Analytical and numerical models are commonly used to relate lifetime prediction and to identify suitable coating and composite substrate combinations based on their potential stress reduction on the interface. Nevertheless, in order to use them, it is necessary to measure the contact adhesion resistance of the multi-layered system interfaces. The rain erosion performance is assessed using an accelerated testing technique, whereby the test material is repeatedly impacted at high speed with water droplets in a Whirling Arm Rain Erosion Rig (WARER). The materials, specifically the coating-laminate interphase region and acoustic properties, are further characterised by several laboratory tests, including Differential Scanning Calorimetry (DSC), pull-off testing, peeling-adhesion testing and nanoindentation testing. This body of work includes a number of case studies. The first case study compares two of the main coating technologies used in industry (i.e., gel coating and LEP); the second case investigates the effects of the in-mould gel coating curing; and the third considers the inclusion of a primer layer on a LEP configuration system. Following these case studies, the LEP is found to be a far superior coating due to its appropriate mechanical and acoustic properties and the interface between the coating and the substrate is highlighted as a key aspect, as poor adhesion can lead to delamination and, ultimately, premature failure of the coating.

18.
ACS Appl Mater Interfaces ; 9(30): 25073-25081, 2017 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-28700216

RESUMEN

Metal halide perovskite solar cells (PSCs) have undergone rapid progress. However, unstable performance caused by sensitivity to environmental moisture and high temperature is a major impediment to commercialization of PSCs. In the present work, a low-temperature, glass-glass encapsulation technique using high performance polyisobutylene (PIB) as the moisture barrier is investigated on planar glass/FTO/TiO2/FAPbI3/PTAA/gold perovskite solar cells. PIB was applied as either an edge seal or blanket layer. Electrical connections to the encapsulated PSCs were provided by either the FTO or Au layers. Results of a "calcium test" demonstrated that a PIB edge-seal effectively prevents moisture ingress. A shelf life test was performed and the PIB-sealed PSC was stable for at least 200 days. Damp heat and thermal cycling tests, in compliance with IEC61215:2016, were used to evaluate different encapsulation methods. Current-voltage measurements were performed regularly under simulated AM1.5G sunlight to monitor changes in PCE. The best results we have achieved to date maintained the initial efficiency after 540 h of damp heat testing and 200 thermal cycles. To the best of the authors' knowledge, these are among the best damp heat and thermal cycle test results for perovskite solar cells published to date. Given the modest performance of the cells (8% averaged from forward and reverse scans) especially with the more challenging FAPbI3 perovskite material tested in this work, it is envisaged that better stability results can be further achieved when higher performance perovskite solar cells are encapsulated using the PIB packaging techniques developed in this work. We propose that heat rather than moisture was the main cause of our PSC degradation. Furthermore, we propose that preventing the escape of volatile decomposition products from the perovskite solar cell materials is the key for stability. PIB encapsulation is a very promising packaging solution for perovskite solar cells, given its demonstrated effectiveness, ease of application, low application temperature, and low cost.

19.
Artículo en Inglés | MEDLINE | ID: mdl-25540718

RESUMEN

Cognitive impairment in patients with bipolar disorder (BD) is not restricted to symptomatic phases. It is also present in euthymia. There is evidence of differences in the brain's structure between bipolar patients and healthy individuals, as well as changes over time in patients. Lithium constitutes the gold standard in long-term prophylactic treatment. Appropriate therapy that prevents new episodes improves the disease's course and reduces the frequency of harmful outcomes. Interestingly, preclinical data suggest that lithium has a (additional) neuroprotective effect. There is limited data on its related effects in humans and even less on its long-term application. In this multi-center cross-sectional study from the International Group for the Study of Lithium-treated Patients (IGSLi), we compared three groups: bipolar patients without long-term lithium treatment (non-Li group; <3 months cumulative lithium exposure, ≥24 months ago), bipolar patients with long-term lithium treatment (Li group, ongoing treatment ≥24 months), and healthy subjects (controls). Strict inclusion and exclusion criteria were defined; the inclusion criteria for patients were diagnosis of BD types I or II, duration of illness ≥10 years, ≥5 episodes in patient's history and a euthymic mood state. Neurocognitive functioning was assessed using the Wechsler Adult Intelligence Scale-Revised (WAIS-R), the California Verbal Learning Test (CVLT), and a visual backward masking (VBM) task. A total of 142 subjects were included, 31 in the non-Li and 58 in the Li group, as well as 53 healthy controls. Treated patients with long-standing BD and controls did not differ significantly in overall cognitive functioning and verbal learning, recall, and recognition; regardless of whether lithium had been part of the treatment. Patients, however, demonstrated poorer early visual information processing than healthy controls, with the lithium-treated patients performing worse than those without. Our data suggest that bipolar patients with a long illness history and effective prophylactic treatment do not reveal significantly impaired general cognitive functioning or verbal learning and memory. However, they are worse at processing early visual information. Accompanying volumetric and spectroscopic data suggest cell loss in patients not treated with lithium that may be counterbalanced by long-term lithium treatment.

20.
ACS Chem Biol ; 9(4): 967-75, 2014 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-24491145

RESUMEN

A series of self-associating foldamers have been designed as heparin reversal agents, as antidotes to prevent bleeding due to this potent antithrombotic agent. The foldamers have a repeating sequence of Lys-Sal, in which Sal is 5-amino-2-methoxy-benzoic acid. These foldamers are designed to self-associate along one face of an extended chain in a ß-sheet-like interaction. The methoxy groups were included to form intramolecular hydrogen bonds that preclude the formation of very large amyloid-like aggregates, while the positively charged Lys side chains were introduced to interact electrostatically with the highly anionic heparin polymer. The prototype compound (Lys-Sal)4 carboxamide weakly associates in aqueous solution at physiological salt concentration in a monomer-dimer-hexamer equilibrium. The association is greatly enhanced at either high ionic strength or in the presence of a heparin derivative, which is bound tightly. Variants of this foldamer are active in an antithrombin III-factor Xa assay, showing their potential as heparin reversal agents.


Asunto(s)
Diseño de Fármacos , Fibrinolíticos/síntesis química , Heparina/química , Modelos Biológicos , Dicroismo Circular , Relación Dosis-Respuesta a Droga , Fibrinolíticos/química , Fibrinolíticos/farmacología , Concentración 50 Inhibidora , Estructura Molecular , Unión Proteica/efectos de los fármacos , Conformación Proteica
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