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Compounds binding to the bromodomains of bromodomain and extra-terminal (BET) family proteins, particularly BRD4, are promising anticancer agents. Nevertheless, side effects and drug resistance pose significant obstacles in BET-based therapeutics development. Using high-throughput screening of a 200,000-compound library, we identified small molecules targeting a phosphorylated intrinsically disordered region (IDR) of BRD4 that inhibit phospho-BRD4 (pBRD4)-dependent human papillomavirus (HPV) genome replication in HPV-containing keratinocytes. Proteomic profiling identified two DNA damage response factors-53BP1 and BARD1-crucial for differentiation-associated HPV genome amplification. pBRD4-mediated recruitment of 53BP1 and BARD1 to the HPV origin of replication occurs in a spatiotemporal and BRD4 long (BRD4-L) and short (BRD4-S) isoform-specific manner. This recruitment is disrupted by phospho-IDR-targeting compounds with little perturbation of the global transcriptome and BRD4 chromatin landscape. The discovery of these protein-protein interaction inhibitors (PPIi) not only demonstrates the feasibility of developing PPIi against phospho-IDRs but also uncovers antiviral agents targeting an epigenetic regulator essential for virus-host interaction and cancer development.
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Infecções por Papillomavirus , Fatores de Transcrição , Humanos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Papillomavirus Humano , Infecções por Papillomavirus/tratamento farmacológico , Infecções por Papillomavirus/genética , Proteômica , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Papillomaviridae/genética , Papillomaviridae/metabolismo , Proteínas Virais/genética , Replicação Viral/fisiologia , Reparo do DNA , Proteínas que Contêm BromodomínioRESUMO
BACKGROUND: Isoniazid preventive therapy (IPT) for child contacts of TB patients, a globally accepted intervention, needs to be evaluated in diverse geographical regions.OBJECTIVES: To assess the extent of IPT coverage and adherence, to ascertain its sociodemographic and programmatic correlates and to explore existing constraints from service providers and beneficiaries´ perspectives.METHODS: A mixed-method study was conducted in January-June 2021 in Paschim Bardhaman District, West Bengal, India. Quantitative assessment was done among 280 child contacts of TB cases registered between January and December 2020 in all TB units in the district. Primary caregivers were interviewed using a pre-designed questionnaire. Two focus group discussions with all senior treatment supervisors of the district and in-depth interviews with 12 purposively selected caregivers of the children were undertaken. Qualitative data were analysed thematically.RESULTS: Only 48.9% (137/280) of child contacts were screened; 58.9% (165/280) were initiated on IPT and 40% (66/165) adhered to a full course. Coverage of the full 6-month IPT among total study participants was 23.6% (66/280). Household visits by health personnel and initial screening significantly predicted increased coverage. Programmatic inadequacies, poor understanding, social stigma and COVID situation were major constraints.CONCLUSION: Coverage of IPT remains unacceptably low and requires health system strengthening for effectively implementing current recommendations of TB preventive treatment.
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Antituberculosos , COVID-19 , Isoniazida , Tuberculose , Criança , Humanos , Antituberculosos/uso terapêutico , Características da Família , Pessoal de Saúde , Isoniazida/uso terapêutico , Tuberculose/prevenção & controleRESUMO
Upper-tract urothelial cancer comprises only 3% of all urothelial cancers. Risk factors include tobacco smoking, recurrent urinary infection, urolithiasis and analgesic abuse. Urolithiasis-induced chronic inflammation leads to urothelial proliferation and eventual malignant transformation. The most common association is reported with squamous cell cancer. A 54-year man under evaluation for right flank pain was diagnosed with a large distal ureteric stone and urothelial cancer of the entire right ureter and renal pelvis. The patient underwent right nephroureterectomy and stone retrieval, with urinary bladder cuff excision and pelvic lymph node dissection. On follow-up, the patient succumbed to disease recurrence with widespread metastasis. Urothelial cancer associated with stone disease is atypical. Long-standing inflammation causing metaplastic and dysplastic changes is a possible hypothesis. Careful assessment of the malignancy should be looked for in patients with long-standing obstruction due to stone disease.
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Carcinoma de Células de Transição/diagnóstico , Neoplasias Renais/diagnóstico , Pelve Renal/patologia , Cálculos Ureterais/diagnóstico , Neoplasias Ureterais/diagnóstico , Carcinoma de Células de Transição/complicações , Carcinoma de Células de Transição/patologia , Carcinoma de Células de Transição/cirurgia , Evolução Fatal , Humanos , Neoplasias Renais/complicações , Neoplasias Renais/patologia , Neoplasias Renais/cirurgia , Pelve Renal/cirurgia , Masculino , Pessoa de Meia-Idade , Nefroureterectomia , Carga Tumoral , Cálculos Ureterais/complicações , Cálculos Ureterais/cirurgia , Neoplasias Ureterais/complicações , Neoplasias Ureterais/patologia , Neoplasias Ureterais/cirurgiaRESUMO
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) causes coronavirus disease-19 (COVID-19), a respiratory illness that can result in hospitalization or death. We investigated associations between rare genetic variants and seven COVID-19 outcomes in 543,213 individuals, including 8,248 with COVID-19. After accounting for multiple testing, we did not identify any clear associations with rare variants either exome-wide or when specifically focusing on (i) 14 interferon pathway genes in which rare deleterious variants have been reported in severe COVID-19 patients; (ii) 167 genes located in COVID-19 GWAS risk loci; or (iii) 32 additional genes of immunologic relevance and/or therapeutic potential. Our analyses indicate there are no significant associations with rare protein-coding variants with detectable effect sizes at our current sample sizes. Analyses will be updated as additional data become available, with results publicly browsable at https://rgc-covid19.regeneron.com.
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SARS-CoV-2 enters host cells by binding angiotensin-converting enzyme 2 (ACE2). Through a genome-wide association study, we show that a rare variant (MAF = 0.3%, odds ratio 0.60, P=4.5×10-13) that down-regulates ACE2 expression reduces risk of COVID-19 disease, providing human genetics support for the hypothesis that ACE2 levels influence COVID-19 risk. Further, we show that common genetic variants define a risk score that predicts severe disease among COVID-19 cases.
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Imaging surface deformation of a coupon specimen in microtensile testing with an optical microscope presents challenges due to the narrow depth of field (DoF) of optical microscopes. Materials being heterogeneous at microscopic length scale, the sample surface deforms into a complex 3D surface texture, evolving continuously as the loading increases. Because of the narrow DoF, the region that is in focus within the field of view (FoV) decreases substantially in size with the increasing out-of-plane heterogeneous deformation. To address this challenge, a method based on image blending and stabilisation of the captured image frames is proposed. Image blending combines the partial regions that are in focus from a set of successive image frames captured at different working distances from the object surface plane to construct a single image that has a large part of the FoV in focus. The blended images are then obtained at different levels of macroscopic strains, that is the global homogeneous strain, in order to characterise the evolution of the heterogeneous deformation. The image stabilisation removes any misalignments of the blended images by spatially realigning them choosing a common feature as a reference point. The validation of the proposed method with conventionally and additively manufactured stainless steel 316L (SS 316L) specimens demonstrates excellent improvement in image quality. Almost 100% of the FoV is maintained in focus regardless of the amount of out-of-plane heterogeneous deformation caused during tensile testing, which is quite remarkable for optical microscopy imaging. Consequently, the blended and stabilised images enhanced the accuracy of digital image correlation (DIC). Time-lapse videos of the deformation generated using these images captured the evolution of the slip bands and their transmission through twinning boundaries in the stainless steel microstructure. Overall, this study demonstrates the feasibility of using image-processing techniques to advance optical microscopy to image complex 3D surfaces evolving with time.
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OBJECTIVES: In 1984, nearly 500,000 inhabitants of Bhopal city, India, were exposed to toxic gases that leaked from a nearby pesticide manufacturing plant. In 1985, four cohorts were established to assess the long-term health impact of exposure, namely, mild, moderate, severely exposed and unexposed groups. The self-reported morbidity data of these cohorts were collected by follow-up cross-sectional surveys at regular intervals over the last 35 years. The present study aimed to analyse the long-term trend of chronic (duration of symptoms >3 months) respiratory morbidity in the four cohorts, stratified by age groups. STUDY DESIGN: The design of this study is a longitudinal analysis of cross-sectional respiratory morbidity data. METHODS: Chronic respiratory morbidity data within the cohorts were analysed at 5-year intervals (first recorded data from 1986). Based on age at the time of exposure, subjects were stratified into four age groups: children (aged <10 years), teenagers (aged ≥10 to <20 years), younger adults (aged ≥20 to <40 years) and older adults (aged ≥40 years). RESULTS: During the first decade, after exposure to the toxic gases, chronic respiratory morbidity in children and teenagers was high (up to 9.1%), which declined thereafter. Progressively increasing chronic respiratory morbidity was observed in both the younger and older adult age groups within all cohorts during the initial 5-10 years after exposure. Respiratory morbidity in both the younger and older adult age groups remained high for 15-20 years and thereafter recorded a declining trend. The highest respiratory morbidity observed during this study in the younger and older adult age groups was 38.6% and 59.5%, respectively; these values were both recorded in the severely exposed cohort. CONCLUSIONS: Exposure to toxic gases released during the Bhopal gas disaster has resulted in chronic respiratory morbidity of the exposed population; this morbidity has continued over decades. The age of the individuals at the time of exposure and exposure severity were crucial determinants of the long-term trend of respiratory morbidity.
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Vazamento Acidental em Bhopal , Exposição Ambiental/efeitos adversos , Gases/efeitos adversos , Doenças Respiratórias/induzido quimicamente , Doenças Respiratórias/mortalidade , Adolescente , Adulto , Criança , Estudos Transversais , Desastres/estatística & dados numéricos , Exposição Ambiental/estatística & dados numéricos , Feminino , Intoxicação por Gás/epidemiologia , Humanos , Índia/epidemiologia , Isocianatos/intoxicação , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Morbidade , Inquéritos e Questionários , Fatores de Tempo , Adulto JovemRESUMO
Energy recovery has been achieved in a multipass linear accelerator, demonstrating a technology for more compact particle accelerators operating at higher currents and reduced energy consumption. Energy delivered to the beam during the first four passes through the accelerating structure was recovered during four subsequent decelerating passes. High-energy efficiency was achieved by the use of superconducting accelerating cavities and permanent magnets. The fixed-field alternating-gradient optical system used for the return loop successfully transported electron bunches of 42, 78, 114, and 150 MeV in a common vacuum chamber. This new kind of accelerator, an eight-pass energy recovery linac, has the potential to accelerate much higher current than existing linear accelerators while maintaining small beam dimensions and consuming much less energy per electron.
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OBJECTIVE: A cross-sectional study was undertaken to assess the prevalence of morbidities in communities residing at variable distances from the closed down insecticide manufacturing plant premises of Union Carbide India Limited (UCIL), Bhopal, India and to determine association of morbidities, if any, with their drinking water usage pattern and distance of localities from the UCIL plant. MATERIALS AND METHODS: A total of 10,827 individuals belonging to 2,184 families, residing within 0-1 km (Stratum I) and 2.5-5.0 km (Stratum II) radial distances from UCIL plant were surveyed and 9,306 of them (86%) were clinically examined. Data were analyzed to examine the association between the groups of morbidities, likely due to biological and chemical water contamination, and the distance of locality from the UCIL plant. Multiple logistic regression was used to explore the risk factors for morbidities. RESULTS: Nearly similar prevalence (25.3% in stratum I, 25.8% in stratum II) and the trend of all-cause morbidities were recorded in the two strata. While morbidities related to gastrointestinal tract system (P < 0.05), auditory system (P < 0.01), neoplasm/cancers (P < 0.01) and congenital anomalies (P < 0.01) were significantly higher in stratum I, the prevalence of hypertension (6.4% stratum II, 4.7% stratum I; P < 0.01) and diabetes mellitus (3.4% stratum II, 2.0% stratum I; P < 0.001) was found significantly higher in stratum II. No association (P > 0.05) was observed between the prevalence of morbidities, likely due to the consumption of biologically or chemically contaminated drinking water, and the distance of locality/stratum from the UCIL plant. DISCUSSION AND CONCLUSION: By and large similar pattern of morbidities were recorded in the two strata suggesting that the communities, irrespective of the distance of their residences from UCIL plant or sources of their drinking water, are equally vulnerable to various morbidities.
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Água Potável/análise , Exposição Ambiental/efeitos adversos , Poluentes Químicos da Água/análise , Poluição da Água/efeitos adversos , Abastecimento de Água , Artrite/epidemiologia , Bronquite/epidemiologia , Estudos Transversais , Diabetes Mellitus/epidemiologia , Desastres , Gastrite/epidemiologia , Humanos , Hipertensão/epidemiologia , Índia/epidemiologia , Pneumopatias Obstrutivas/epidemiologia , Morbidade , Neoplasias/epidemiologia , Prevalência , Características de Residência , Infecções Respiratórias/epidemiologiaRESUMO
Mucosotropic human papillomaviruses (HPVs) cause prevalent anogenital infections, some of which can progress to cancers. It is imperative to identify efficacious drug candidates, as there are few therapeutic options. We have recapitulated a robust productive program of HPV-18 in organotypic raft cultures of primary human keratinocytes. The HPV E7 protein induces S phase reentry, along with DNA damage response (DDR) in differentiated cells to support viral DNA amplification. A number of small molecule inhibitors of DDR regulators are in clinical use or clinical trials to treat cancers. Here, we used our raft culture system to examine effects of inhibitors of ATR/Chk1 and ATM/Chk2 on HPV infection. The inhibitors impaired S-phase reentry and progression as well as HPV DNA amplification. The Chk1 inhibitor MK-8776 was most effective, reducing viral DNA amplification by 90-99% and caused DNA damage and apoptosis, preferentially in HPV infected cells. We found that this sensitivity was imparted by the E7 protein and report that MK-8776 also caused extensive cell death of cervical cancer cell lines. Furthermore, it sensitized the cells to cisplatin, commonly used to treat advanced cervical cancer. Based on these observations, the Chk1 inhibitors could be potential effective agents to be re-purposed to treat the spectrum of HPV infections in single or combination therapy.
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DNA Viral/antagonistas & inibidores , Papillomavirus Humano 18/metabolismo , Queratinócitos/efeitos dos fármacos , Proteínas E7 de Papillomavirus/metabolismo , Pirazóis/farmacologia , Pirimidinas/farmacologia , Replicação Viral/efeitos dos fármacos , Antineoplásicos/farmacologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Células Cultivadas , Cisplatino/farmacologia , DNA Viral/genética , DNA Viral/metabolismo , Feminino , Células HeLa , Papillomavirus Humano 18/genética , Papillomavirus Humano 18/fisiologia , Humanos , Queratinócitos/metabolismo , Queratinócitos/virologia , Masculino , Proteínas E7 de Papillomavirus/genética , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/prevenção & controle , Infecções por Papillomavirus/virologia , Inibidores de Proteínas Quinases/farmacologia , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia , Replicação Viral/genéticaAssuntos
Antivirais/farmacologia , Proteínas de Ligação a DNA/metabolismo , Papillomavirus Humano 18/efeitos dos fármacos , Óxido Nítrico/metabolismo , Proteínas Oncogênicas Virais/metabolismo , Proteínas E7 de Papillomavirus/metabolismo , Siloxanas/farmacologia , Células Cultivadas , Ensaios Clínicos Fase II como Assunto , Replicação do DNA , Proteínas de Ligação a DNA/genética , Prepúcio do Pênis/citologia , Papillomavirus Humano 18/genética , Papillomavirus Humano 18/fisiologia , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/virologia , Masculino , Proteínas Oncogênicas Virais/genética , Proteínas E7 de Papillomavirus/genética , Replicação ViralRESUMO
Human papillomaviruses (HPVs) cause epithelial proliferative diseases. Persistent infection of the mucosal epithelia by the high-risk genotypes can progress to high-grade dysplasia and cancers. Viral transcription and protein activities are intimately linked to regulation by histone acetyltransferases and histone deacetylases (HDACs) that remodel chromatin and regulate gene expression. HDACs are also essential to remodel and repair replicating chromatin to enable the progression of replication forks. As such, Vorinostat (suberoylanilide hydroximic acid), and other pan-HDAC inhibitors, are used to treat lymphomas. Here, we investigated the effects of Vorinostat on productive infection of the high-risk HPV-18 in organotypic cultures of primary human keratinocytes. HPV DNA amplifies in the postmitotic, differentiated cells of squamous epithelia, in which the viral oncoproteins E7 and E6 establish a permissive milieu by destabilizing major tumor suppressors, the pRB family proteins and p53, respectively. We showed that Vorinostat significantly reduced these E6 and E7 activities, abrogated viral DNA amplification, and inhibited host DNA replication. The E7-induced DNA damage response, which is critical for both events, was also compromised. Consequently, Vorinostat exposure led to DNA damage and triggered apoptosis in HPV-infected, differentiated cells, whereas uninfected tissues were spared. Apoptosis was attributed to highly elevated proapoptotic Bim isoforms that are known to be repressed by EZH2 in a repressor complex containing HDACs. Two other HDAC inhibitors, Belinostat and Panobinostat, also inhibited viral DNA amplification and cause apoptosis. We suggest that HDAC inhibitors are promising therapeutic agents to treat benign HPV infections, abrogate progeny virus production, and hence interrupt transmission.
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Replicação do DNA/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Papillomavirus Humano 18/genética , Proteínas Oncogênicas Virais/metabolismo , Infecções por Papillomavirus/tratamento farmacológico , Vorinostat/farmacologia , Apoptose/efeitos dos fármacos , Proteína 11 Semelhante a Bcl-2/metabolismo , Células Cultivadas , Reparo do DNA/efeitos dos fármacos , DNA Viral/genética , Histonas/metabolismo , Papillomavirus Humano 18/efeitos dos fármacos , Humanos , Ácidos Hidroxâmicos/farmacologia , Queratinócitos/virologia , Mucosa/virologia , Panobinostat/farmacologia , Infecções por Papillomavirus/prevenção & controle , Infecções por Papillomavirus/transmissão , Sulfonamidas/farmacologia , Proteína Supressora de Tumor p53/metabolismoRESUMO
Observed enrichments of N (and the δ15N of this N) in volcanic glasses altered on Earth's modern and ancient seafloor are relevant in considerations of modern global N subduction fluxes and ancient life on Earth, and similarly altered glasses on Mars and other extraterrestrial bodies could serve as valuable tracers of biogeochemical processes. Palagonitized glasses and whole-rock samples of volcanic rocks on the modern seafloor (ODP Site 1256D) contain 3-18 ppm N with δ15Nair values of up to +4.5. Variably altered glasses from Mesozoic ophiolites (Troodos, Cyprus; Stonyford volcanics, USA) contain 2-53 ppm N with δ15N of -6.3 to +7. All of the more altered glasses have N concentrations higher than those of fresh volcanic glass (for MORB, <2 ppm N), reflecting significant N enrichment, and most of the altered glasses have δ15N considerably higher than that of their unaltered glass equivalents (for MORB, -5 ± 2). Circulation of hydrothermal fluids, in part induced by nearby spreading-center magmatism, could have leached NH4+ from sediments then fixed this NH4+ in altering volcanic glasses. Glasses from each site contain possible textural evidence for microbial activity in the form of microtubules, but any role of microbes in producing the N enrichments and elevated δ15N remains uncertain. Petrographic analysis, and imaging and chemical analyses by scanning electron microscopy and scanning transmission electron microscopy, indicate the presence of phyllosilicates (smectite, illite) in both the palagonitized cracks and the microtubules. These phyllosilicates (particularly illite), and possibly also zeolites, are the likely hosts for N in these glasses. Key Words: Nitrogen-Nitrogen isotope-Palagonite-Volcanic glass-Mars. Astrobiology 18, 330-342.
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Exobiologia , Vidro/química , Isótopos de Nitrogênio/análise , Nitrogênio/análise , Silicatos/química , Bactérias/metabolismo , Planeta Terra , Imageamento Tridimensional , Oceanos e Mares , Erupções VulcânicasAssuntos
Antivirais/farmacologia , Guanina/análogos & derivados , Organofosfonatos/farmacologia , Papillomaviridae/efeitos dos fármacos , Pró-Fármacos/farmacologia , Animais , Dano ao DNA , Replicação do DNA/efeitos dos fármacos , DNA Viral , Avaliação Pré-Clínica de Medicamentos , Guanina/farmacologia , Humanos , Replicação Viral/efeitos dos fármacosRESUMO
Characterizing the complex interplay of cellular processes in cancer would enable the discovery of key mechanisms underlying its development and progression. Published approaches to decipher driver mechanisms do not explicitly model tissue-specific changes in pathway networks and the regulatory disruptions related to genomic aberrations in cancers. We therefore developed InFlo, a novel systems biology approach for characterizing complex biological processes using a unique multidimensional framework integrating transcriptomic, genomic and/or epigenomic profiles for any given cancer sample. We show that InFlo robustly characterizes tissue-specific differences in activities of signalling networks on a genome scale using unique probabilistic models of molecular interactions on a per-sample basis. Using large-scale multi-omics cancer datasets, we show that InFlo exhibits higher sensitivity and specificity in detecting pathway networks associated with specific disease states when compared to published pathway network modelling approaches. Furthermore, InFlo's ability to infer the activity of unmeasured signalling network components was also validated using orthogonal gene expression signatures. We then evaluated multi-omics profiles of primary high-grade serous ovarian cancer tumours (N=357) to delineate mechanisms underlying resistance to frontline platinum-based chemotherapy. InFlo was the only algorithm to identify hyperactivation of the cAMP-CREB1 axis as a key mechanism associated with resistance to platinum-based therapy, a finding that we subsequently experimentally validated. We confirmed that inhibition of CREB1 phosphorylation potently sensitized resistant cells to platinum therapy and was effective in killing ovarian cancer stem cells that contribute to both platinum-resistance and tumour recurrence. Thus, we propose InFlo to be a scalable and widely applicable and robust integrative network modelling framework for the discovery of evidence-based biomarkers and therapeutic targets.
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Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , AMP Cíclico/metabolismo , Resistencia a Medicamentos Antineoplásicos , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/metabolismo , Biologia de Sistemas/métodos , Linhagem Celular Tumoral , Feminino , Redes Reguladoras de Genes/efeitos dos fármacos , Humanos , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Transdução de Sinais/efeitos dos fármacosRESUMO
Thin film magnetic heterostructures with competing interfacial coupling and Zeeman energy provide a fertile ground to study phase transition between different equilibrium states as a function of external magnetic field and temperature. A rare-earth (RE)/transition metal (TM) ferromagnetic multilayer is a classic example where the magnetic state is determined by a competition between the Zeeman energy and antiferromagnetic interfacial exchange coupling energy. Technologically, such structures offer the possibility to engineer the macroscopic magnetic response by tuning the microscopic interactions between the layers. We have performed an exhaustive study of nickel/gadolinium as a model system for understanding RE/TM multilayers using the element-specific measurement technique x-ray magnetic circular dichroism, and determined the full magnetic state diagrams as a function of temperature and magnetic layer thickness. We compare our results to a modified Stoner-Wohlfarth-based model and provide evidence of a thickness-dependent transition to a magnetic fan state which is critical in understanding magnetoresistance effects in RE/TM systems. The results provide important insight for spintronics and superconducting spintronics where engineering tunable magnetic inhomogeneity is key for certain applications.
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Wound healing involves a number of factors that results in the production of a "closed" wound. Studies have shown, in animal models, acceleration of wound healing with the addition of adipose-derived stromal cells (ADSC). The cause for the positive effect which these cells have on wound healing has not been elucidated. We have previously shown that addition of ADSC to the dermal equivalent in 3-dimensional skin cultures accelerates reepithelialization. We now demonstrate that conditioned media (CM) from cultured ADSC produced a similar rate of healing. This result suggests that a feedback from the 3-dimensional epithelial cultures to ADSC was not necessary to effect the accelerated reepithelialization. Mass spectrometry of CM from ADSC and primary human fibroblasts revealed differences in secretomes, some of which might have roles in the accelerating wound healing. Thus, the use of CM has provided some preliminary information on a possible mode of action.
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Células-Tronco Mesenquimais/fisiologia , Reepitelização/fisiologia , Gordura Subcutânea Abdominal/citologia , Técnicas de Cultura de Tecidos/métodos , Meios de Cultivo Condicionados , Fibroblastos/fisiologia , Humanos , Pele , Cicatrização/fisiologiaRESUMO
We present the fabrication and testing of engineered microballoon particles that expand and contract under external pressure changes hence serving as microscopic pressure sensors. The particles consist of 12 µm hollow flexible 0.4 µm-thick parylene-C shells with and without a coating of ultrathin Al2O3 diffusion barriers, and the changes in the particle radius are measured from the particle spectral reflectivity. The microballoons display radial pressure sensitivities of 0.64 nm psi(-1) and 0.44 nm psi(-1), respectively in agreement with theoretical estimates. The microballoon devices were used for mapping the internal pressure drop within microfluidic chips. These devices experience nearly spherical symmetry which could make them potential flow-through sensors for the augmentation of particle-based flow characterization methodologies extending today's capabilities of particle imaging velocimetry.
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Piezoelectricity and flexoelectricity are two independent but not incompatible forms of electromechanical response exhibited by nanoscale ferroelectrics. Here, we show that flexoelectricity can either enhance or suppress the piezoelectric response of the cantilever depending on the ferroelectric polarity and lead to a diode-like asymmetric (two-state) electromechanical response.