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Recent single-cell RNA sequencing studies have revealed distinct microglial states in development and disease. These include proliferative-region-associated microglia (PAMs) in developing white matter and disease-associated microglia (DAMs) prevalent in various neurodegenerative conditions. PAMs and DAMs share a similar core gene signature. However, the extent of the dynamism and plasticity of these microglial states, as well as their functional significance, remains elusive, partly due to the lack of specific tools. Here, we generated an inducible Cre driver line, Clec7a-CreERT2, that targets PAMs and DAMs in the brain parenchyma. Utilizing this tool, we profiled labeled cells during development and in several disease models, uncovering convergence and context-dependent differences in PAM and DAM gene expression. Through long-term tracking, we demonstrated microglial state plasticity. Lastly, we specifically depleted DAMs in demyelination, revealing their roles in disease recovery. Together, we provide a versatile genetic tool to characterize microglial states in CNS development and disease.
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Plasticidade Celular , Microglia , Remielinização , Microglia/fisiologia , Animais , Camundongos , Plasticidade Celular/genética , Doenças Desmielinizantes/genética , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Modelos Animais de Doenças , Encéfalo , Bainha de Mielina/metabolismo , Substância Branca/patologiaRESUMO
The wealth of complex polar topologies1-10 recently found in nanoscale ferroelectrics results from a delicate balance between the intrinsic tendency of the materials to develop a homogeneous polarization and the electric and mechanical boundary conditions imposed on them. Ferroelectric-dielectric interfaces are model systems in which polarization curling originates from open circuit-like electric boundary conditions, to avoid the build-up of polarization charges through the formation of flux-closure11-14 domains that evolve into vortex-like structures at the nanoscale15-17 level. Although ferroelectricity is known to couple strongly with strain (both homogeneous18 and inhomogeneous19,20), the effect of mechanical constraints21 on thin-film nanoscale ferroelectrics has been comparatively less explored because of the relative paucity of strain patterns that can be implemented experimentally. Here we show that the stacking of freestanding ferroelectric perovskite layers with controlled twist angles provides an opportunity to tailor these topological nanostructures in a way determined by the lateral strain modulation associated with the twisting. Furthermore, we find that a peculiar pattern of polarization vortices and antivortices emerges from the flexoelectric coupling of polarization to strain gradients. This finding provides opportunities to create two-dimensional high-density vortex crystals that would enable us to explore previously unknown physical effects and functionalities.
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The arachnoid barrier delineates the border between the central nervous system and dura mater. Although the arachnoid barrier creates a partition, communication between the central nervous system and the dura mater is crucial for waste clearance and immune surveillance1,2. How the arachnoid barrier balances separation and communication is poorly understood. Here, using transcriptomic data, we developed transgenic mice to examine specific anatomical structures that function as routes across the arachnoid barrier. Bridging veins create discontinuities where they cross the arachnoid barrier, forming structures that we termed arachnoid cuff exit (ACE) points. The openings that ACE points create allow the exchange of fluids and molecules between the subarachnoid space and the dura, enabling the drainage of cerebrospinal fluid and limited entry of molecules from the dura to the subarachnoid space. In healthy human volunteers, magnetic resonance imaging tracers transit along bridging veins in a similar manner to access the subarachnoid space. Notably, in neuroinflammatory conditions such as experimental autoimmune encephalomyelitis, ACE points also enable cellular trafficking, representing a route for immune cells to directly enter the subarachnoid space from the dura mater. Collectively, our results indicate that ACE points are a critical part of the anatomy of neuroimmune communication in both mice and humans that link the central nervous system with the dura and its immunological diversity and waste clearance systems.
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Aracnoide-Máter , Encéfalo , Dura-Máter , Animais , Humanos , Camundongos , Aracnoide-Máter/anatomia & histologia , Aracnoide-Máter/irrigação sanguínea , Aracnoide-Máter/imunologia , Aracnoide-Máter/metabolismo , Transporte Biológico , Encéfalo/anatomia & histologia , Encéfalo/irrigação sanguínea , Encéfalo/imunologia , Encéfalo/metabolismo , Dura-Máter/anatomia & histologia , Dura-Máter/irrigação sanguínea , Dura-Máter/imunologia , Dura-Máter/metabolismo , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/metabolismo , Perfilação da Expressão Gênica , Imageamento por Ressonância Magnética , Camundongos Transgênicos , Espaço Subaracnóideo/anatomia & histologia , Espaço Subaracnóideo/irrigação sanguínea , Espaço Subaracnóideo/imunologia , Espaço Subaracnóideo/metabolismo , Líquido Cefalorraquidiano/metabolismo , Veias/metabolismoRESUMO
Microquasars are laboratories for the study of jets of relativistic particles produced by accretion onto a spinning black hole. Microquasars are near enough to allow detailed imaging of spatial features across the multiwavelength spectrum. The recent extension measurement of the spatial morphology of a microquasar, SS 433, to TeV gamma rays1 localizes the acceleration of electrons at shocks in the jet far from the black hole2. V4641 Sagittarii (V4641 Sgr) is a similar binary system with a black hole and B-type main-sequence companion star and has an orbit period of 2.8 days (refs. 3,4). It stands out for its super-Eddington accretion5 and for its radio jet, which is one of the fastest superluminal jets in the Milky Way. Previous observations of V4641 Sgr did not report gamma-ray emission6. Here we report TeV gamma-ray emission from V4641 Sgr that reveals particle acceleration at similar distances from the black hole as SS 433. Furthermore, the gamma-ray spectrum of V4641 Sgr is among the hardest TeV spectra observed from any known gamma-ray source and is detected above 200 TeV. Gamma rays are produced by particles, either electrons or protons, of higher energies. Because energetic electrons lose energy more quickly the higher their energy, such a spectrum either very strongly constrains the electron-production mechanism or points to the acceleration of high-energy protons. This suggests that large-scale jets from microquasars could be more common than previously expected and that they could be a notable source of galactic cosmic rays7-9.
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Moisture-capturing hydrogels have emerged as attractive sorbent materials capable of converting ambient humidity into liquid water. Recent works have demonstrated exceptional water capture capabilities of hydrogels while simultaneously exploring different strategies to accelerate water capture and release. However, on the material level, an understanding of the intrinsic transport properties of moisture-capturing hydrogels is currently missing, which hinders their rational design. In this work, we combine absorption and desorption experiments of macroscopic hydrogel samples in pure vapor with models of water diffusion in the hydrogels to demonstrate the first measurements of the intrinsic water diffusion coefficient in hydrogel-salt composites. Based on these insights, we pattern hydrogels with micropores to significantly decrease the required absorption and desorption times by 19% and 72%, respectively, while reducing the total water capacity of the hydrogel by only 4%. Thereby, we provide an effective strategy toward hydrogel material optimization, with a particular significance in pure-vapor environments.
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BACKGROUND: Identification of tumor-derived variants in circulating tumor DNA (ctDNA) has potential as a sensitive and reliable surrogate for tumor tissue-based routine diagnostic testing. However, variations in pre(analytical) procedures affect the efficiency of ctDNA recovery. Here, an external quality assessment (EQA) was performed to determine the performance of ctDNA mutation detection work flows that are used in current diagnostic settings across laboratories within the Dutch COIN consortium (ctDNA on the road to implementation in The Netherlands). METHODS: Aliquots of 3 high-volume diagnostic leukapheresis (DLA) plasma samples and 3 artificial reference plasma samples with predetermined mutations were distributed among 16 Dutch laboratories. Participating laboratories were requested to perform ctDNA analysis for BRAF exon 15, EGFR exon 18-21, and KRAS exon 2-3 using their regular circulating cell-free DNA (ccfDNA) analysis work flow. Laboratories were assessed based on adherence to the study protocol, overall detection rate, and overall genotyping performance. RESULTS: A broad range of preanalytical conditions (e.g., plasma volume, elution volume, and extraction methods) and analytical methodologies (e.g., droplet digital PCR [ddPCR], small-panel PCR assays, and next-generation sequencing [NGS]) were used. Six laboratories (38%) had a performance score of >0.90; all other laboratories scored between 0.26 and 0.80. Although 13 laboratories (81%) reached a 100% overall detection rate, the therapeutically relevant EGFR p.(S752_I759del) (69%), EGFR p.(N771_H773dup) (50%), and KRAS p.(G12C) (48%) mutations were frequently not genotyped accurately. CONCLUSIONS: Divergent (pre)analytical protocols could lead to discrepant clinical outcomes when using the same plasma samples. Standardization of (pre)analytical work flows can facilitate the implementation of reproducible liquid biopsy testing in the clinical routine.
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DNA Tumoral Circulante , Humanos , DNA Tumoral Circulante/sangue , DNA Tumoral Circulante/genética , Mutação , Neoplasias/genética , Neoplasias/sangue , Proteínas Proto-Oncogênicas p21(ras)/genética , Receptores ErbB/genética , Receptores ErbB/sangue , Proteínas Proto-Oncogênicas B-raf/genética , Países BaixosRESUMO
OBJECTIVE: Systemic sclerosis-interstitial lung disease (SSc-ILD) is the leading cause of death in SSc, affecting around 50 % of the patients. Lung tissue of patients with early-stage SSc-ILD is characterized by a predominant inflammatory response with inconspicuous fibrosis, which may progress to honeycombing fibrosis. Hence, a better understanding of the molecular mechanisms underpinning SSc-ILD pathogenesis is needed to improve treatment options and progression prediction. This transcriptomic study aims to reveal the differential gene expression between control (ctrl) lung tissue and inflammatory, prefibrotic and fibrotic lung tissue to capture progression of early to late phase SSc-ILD. METHODS: Twelve explanted lungs from patients with SSc-ILD were used to analyze gene expression from formalin-fixed paraffin-embedded lung tissues with varying stages of ILD (n = 18) and control lung tissue (n = 6). The SSc-ILD tissues were stratified into three ROIs: inflammatory, prefibrotic, and fibrotic using histological assessments to define a longitudinal simulation of early to late phases of SSc-ILD. The nanoString (nS) nCounter Human Fibrosis Panel was used to profile the transcriptome in the regions of interest. Validation of potential targetswas performed with immunohistochemistry in the same tissues that were used for transcriptome analysis. RESULTS: To validate our simulation model, we performed subgroup analysis that showed an incremental increase in pathway scores related to the severity of fibrosis. Ctrl vs SSc-ILD comparison demonstrated 24 differentially expressed genes, two of which had the most pronounced p-values. Cyclin-dependent kinase inhibitor (cdkn2c) was overexpressed (P = 0.00052) in SSc-ILD compared to ctrl, while expression of Pellino E3 ubiquitin-protein ligase 1 (peli1) showed lower expression (P = 0.0012). Additionally, in all four groups, cdkn2c and peli1 gene expression showed an incremental increase and decrease, respectively. Immunohistochemistry of cdkn2c showed consistent results with the nS analysis. CONCLUSION: More cdkn2c and less peli1 expression were associated with more advanced stages of SSc-ILD on histologic assessment. We report the potential of the cell cycle inhibitor and senescence marker, cdkn2c (p18) to be associated with fibrosis progression.
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Progressão da Doença , Perfilação da Expressão Gênica , Doenças Pulmonares Intersticiais , Pulmão , Escleroderma Sistêmico , Transcriptoma , Humanos , Escleroderma Sistêmico/genética , Escleroderma Sistêmico/patologia , Escleroderma Sistêmico/metabolismo , Doenças Pulmonares Intersticiais/genética , Doenças Pulmonares Intersticiais/metabolismo , Pulmão/patologia , Pulmão/metabolismo , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , BiomarcadoresRESUMO
OBJECTIVE: Vaginal dryness is an important factor influencing sexual function in women with primary Sjögren syndrome (pSS). Previous studies showed a higher degree of inflammation in vaginal biopsies from patients with pSS compared to non-pSS controls. However, the molecular pathways that drive this inflammation remain unclear. Therefore, the aim of this study was to investigate inflammatory pathway activity in the vaginal tissue of patients with pSS. METHODS: Vaginal biopsies of 8 premenopausal patients with pSS experiencing vaginal dryness and 7 age-matched non-pSS controls were included. Expression of genes involved in inflammation and tissue homeostasis was measured using NanoString technology and validated using TaqMan Real-Time PCR. Vaginal tissue sections were stained by immunohistochemistry for myxovirus resistance protein 1 (MxA) and CD123 (plasmacytoid dendritic cells [pDCs]). RESULTS: The most enriched pathway in vaginal biopsies from patients with pSS compared to non-pSS controls was the interferon (IFN) signaling pathway (P < 0.01). Pathway scores for Janus kinase and signal transducer and activator of transcription (JAK-STAT) and Notch signaling were also higher (P < 0.01 for both pathways). Conversely, transforming growth factor-ß signaling and angiogenesis pathway scores were lower in pSS (P = 0.02 and P = 0.04, respectively). Differences in IFN signaling between patients with pSS and non-pSS controls were confirmed by PCR and MxA tissue staining. No CD123+ pDCs were detected in vaginal biopsies. IFN-stimulated gene expression levels correlated positively with CD45+ cell numbers in vaginal biopsies and serum anti-SSA/Ro positivity. CONCLUSION: Upregulation of IFN signaling in vaginal tissue of women with pSS, along with its association with tissue pathology, suggests that IFNs contribute to inflammation of the vaginal wall and potentially also to clinical symptomatology (ie, vaginal dryness).
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Interferons , Transdução de Sinais , Síndrome de Sjogren , Vagina , Humanos , Feminino , Síndrome de Sjogren/metabolismo , Síndrome de Sjogren/imunologia , Síndrome de Sjogren/patologia , Vagina/patologia , Vagina/imunologia , Vagina/metabolismo , Adulto , Pessoa de Meia-Idade , Interferons/metabolismo , Proteínas de Resistência a Myxovirus/genética , Proteínas de Resistência a Myxovirus/metabolismo , Biópsia , Doenças Vaginais/metabolismo , Doenças Vaginais/patologia , Doenças Vaginais/imunologiaRESUMO
Serous tubal intraepithelial carcinoma (STIC) is regarded as the origin of most high-grade serous carcinomas (HGSC). After a diagnosis of isolated STIC, risk of developing HGSC is substantial. Since surveillance cannot detect HGSC in time to cure the disease, there is no consensus on the optimal treatment after a diagnosis of isolated STIC, but chemotherapy is considered one of the possible strategies. In this case report, we describe 2 women with advanced-stage HGSC treated with 3 cycles of neoadjuvant chemotherapy followed by interval debulking surgery. In both women, histopathological examination showed a complete histopathological tumor response, but a vital STIC was found in both cases. The 2 cases presented here indicate that STICs may not respond to chemotherapy. Further research focused on the underlying biology and chemosensitivity of STIC, as well as the effectiveness of treatment to prevent HGSC in case of isolated STIC, is needed.
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In this Letter, owing to a production error, the penultimate version of the PDF was published. The HTML version was always correct. The PDF has been corrected online.
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SS 433 is a binary system containing a supergiant star that is overflowing its Roche lobe with matter accreting onto a compact object (either a black hole or neutron star)1-3. Two jets of ionized matter with a bulk velocity of approximately 0.26c (where c is the speed of light in vacuum) extend from the binary, perpendicular to the line of sight, and terminate inside W50, a supernova remnant that is being distorted by the jets2,4-8. SS 433 differs from other microquasars (small-scale versions of quasars that are present within our own Galaxy) in that the accretion is believed to be super-Eddington9-11, and the luminosity of the system is about 1040 ergs per second2,9,12,13. The lobes of W50 in which the jets terminate, about 40 parsecs from the central source, are expected to accelerate charged particles, and indeed radio and X-ray emission consistent with electron synchrotron emission in a magnetic field have been observed14-16. At higher energies (greater than 100 gigaelectronvolts), the particle fluxes of γ-rays from X-ray hotspots around SS 433 have been reported as flux upper limits6,17-20. In this energy regime, it has been unclear whether the emission is dominated by electrons that are interacting with photons from the cosmic microwave background through inverse-Compton scattering or by protons that are interacting with the ambient gas. Here we report teraelectronvolt γ-ray observations of the SS 433/W50 system that spatially resolve the lobes. The teraelectronvolt emission is localized to structures in the lobes, far from the centre of the system where the jets are formed. We have measured photon energies of at least 25 teraelectronvolts, and these are certainly not Doppler-boosted, because of the viewing geometry. We conclude that the emission-from radio to teraelectronvolt energies-is consistent with a single population of electrons with energies extending to at least hundreds of teraelectronvolts in a magnetic field of about 16 microgauss.
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BACKGROUND: Pain is a side effect of Granulocyte-Colony Stimulating Factor (G-CSF) administration. This prospective study investigates various aspects including pain perception occurring in Peripheral Blood Stem Cell (PBSC) donors. MATERIALS AND METHODS: Related and unrelated PBSC donors were prospectively studied. Donors recorded pain symptoms during the four-day period of G-CSF administration using the McGill Pain Questionnaire, a Visual Analog Scale and a pain diary. RESULTS: There were 208 donors included, 102 (49%) related and 106 (51%) unrelated donors. Ninety-two percent of all reported the occurrence of pain. Moderate or severe pain was reported by 52%. No differences were found between related and unrelated donors. Pain occurred more often in females (p = 0.035). Relatively young donors (age 16-30 years) more frequently showed to have pain in comparison to older donors (>50 years) (p = 0.006). Musculoskeletal pain was most frequently distributed in the gluteal and lower back region (65-71%). Irrespective of the pain location, pain was most often described as nagging, annoying, however tolerable. Donors experiencing pain most on days of G-CSF administration, most frequently occurring during relaxation or at night. Sleep-mode was often affected. The use of paracetamol (acetaminophen) was sufficient for all but one donor. CONCLUSION: This is the first study to describe different aspects of pain associated with G-CSF administration in donors. Although the observed pain was tolerable, it should never be neglected. Knowledge derived from this study is of use for staff members involved in donor information and care management.
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Células-Tronco de Sangue Periférico , Humanos , Feminino , Masculino , Adulto , Adolescente , Pessoa de Meia-Idade , Estudos Prospectivos , Dor , Adulto Jovem , Manejo da Dor/métodos , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Doadores de SangueRESUMO
Cribriform adenocarcinoma of salivary gland (CASG) is a rare, salivary gland tumor. In this report, we describe a case of CASG harboring a novel PPP2R2A::PRKD1 fusion. A 58-year-old female presented with an intraoral mass adjacent to the lower left third molar region. Morphological features at histological examination, immunohistochemical staining (p63+, p40-), and tumor location were indicative of CASG. However, due to the potential focal presence of a biphasic component within the tumor, RNA sequencing was performed to confirm the diagnosis. The subsequently found novel PPP2R2A::PRKD1 fusion adds to the rapidly evolving molecular landscape of salivary gland tumors. Additionally, we report that CASG may show some entrapment of pre-existent salivary gland ducts, which may be misinterpreted as tumor cells with myoepithelial differentiation.
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Adenocarcinoma , Neoplasias das Glândulas Salivares , Feminino , Humanos , Pessoa de Meia-Idade , Adenocarcinoma/patologia , Glândulas Salivares , Fatores de Transcrição , Neoplasias das Glândulas Salivares/patologia , Biomarcadores Tumorais/genética , Proteína Fosfatase 2/genéticaRESUMO
The ability to assess cell proliferation and viability is essential for assessing new drug treatments, particularly in cancer drug discovery. This study describes a new method that uses a plate reader digital microscopy cell imaging and analysis system to assess cell proliferation and viability. This imaging system utilizes high throughput fluorescence microscopy with two fluorescent probes: cell membrane-impermeable SYTOX green and nuclear binding Hoechst-33342. Here we compare this technology to other known viability assays, namely: propidium iodide (PI)-based flow cytometry, and sulforhodamine B (SRB) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) based plate reader assays. These methods were assessed based on their effectiveness in detecting the cell numbers of two adherent cell lines and one suspension cell line. Automated cell imaging was most accurate at measuring cell number in both adherent and suspension cell lines. The PI-based flow cytometry method was more difficult to use with adherent cells, while the SRB and MTT assays had difficulties when monitoring cells in suspension. Despite these challenges, it was possible to obtain similar results when quantifying the effect of cytotoxic compounds. This study demonstrates that the digital microscopy automated cell imaging system is an effective method for assessing cell proliferation and the cytotoxic effect of compounds on both adherent and suspension cell lines.
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Proliferação de Células , Sobrevivência Celular , Microscopia de Fluorescência , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Citometria de Fluxo , Corantes Fluorescentes/química , Linhagem Celular Tumoral , Sais de Tetrazólio/químicaRESUMO
When developing models for clinical information retrieval and decision support systems, the discrete outcomes required for training are often missing. These labels need to be extracted from free text in electronic health records. For this extraction process one of the most important contextual properties in clinical text is negation, which indicates the absence of findings. We aimed to improve large scale extraction of labels by comparing three methods for negation detection in Dutch clinical notes. We used the Erasmus Medical Center Dutch Clinical Corpus to compare a rule-based method based on ContextD, a biLSTM model using MedCAT and (finetuned) RoBERTa-based models. We found that both the biLSTM and RoBERTa models consistently outperform the rule-based model in terms of F1 score, precision and recall. In addition, we systematically categorized the classification errors for each model, which can be used to further improve model performance in particular applications. Combining the three models naively was not beneficial in terms of performance. We conclude that the biLSTM and RoBERTa-based models in particular are highly accurate accurate in detecting clinical negations, but that ultimately all three approaches can be viable depending on the use case at hand.
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Registros Eletrônicos de Saúde , Aprendizado de Máquina , Armazenamento e Recuperação da Informação , Processamento de Linguagem NaturalRESUMO
BACKGROUND: Compared with women who are human immunodeficiency virus (HIV) negative, women with human immunodeficiency virus (WWH) have a higher human papillomavirus (HPV) prevalence and increased cervical cancer risk, emphasizing the need for effective cervical cancer screening in this population. The present study aimed to validate methylation markers ASCL1 and LHX8 for primary screening in a South African cohort of WWH. METHODS: In this post hoc analysis within the DIAgnosis in Vaccine And Cervical Cancer Screen (DiaVACCS) study, a South African observational multicenter cohort study, cervical scrape samples from 411 HIV-positive women were analyzed for hypermethylation of ASCL1 and LHX8 genes, HPV DNA, and cytology. Sensitivities, specificities, and positive and negative predictive values of primary methylation-based, HPV-based and cytology-based screening were calculated for the detection of cervical intraepithelial neoplasia of grade 3 or higher. RESULTS: Single markers ASCL1 and LHX8 resulted in a good performance for the detection of cervical intraepithelial neoplasia of grade 3 or higher, with sensitivities of 85.9% (95% confidence interval [CI], 78.2%-93.6%) and 89.7% (83.0%-96.5%), respectively, and specificities of 72.9% (67.3%-78.5%) and 75.0% (69.5%-80.5%). Combining markers ASCL1 and LHX8 resulted in a lower sensitivity compared with HPV testing (84.6% vs 93.6%, respectively; ratio, 0.90 [95% CI, .82-.99]) and a higher specificity (86.7% vs 78.3%; ratio 1.11 [1.02-1.20]) and reduced the referral rate from 46.8% to 33.4%. ASCL1/LHX8 methylation had a significantly higher sensitivity than cytology (threshold, high-grade intraepithelial squamous lesion or worse), (84.6% vs 74.0%, respectively; ratio, 1.16 [95% CI, 1.01-1.32]) and similar specificity (86.7% vs 91.0%; ratio, 0.95 [.90-1.003]). CONCLUSIONS: Our results validate the accuracy of ASCL1/LHX8 methylation analysis for primary screening in WWH, which offers a full-molecular alternative to cytology- or HPV-based screening, without the need for additional triage testing.
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Infecções por Papillomavirus , Displasia do Colo do Útero , Neoplasias do Colo do Útero , Feminino , Humanos , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/epidemiologia , HIV , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/epidemiologia , Detecção Precoce de Câncer , Estudos de Coortes , África do Sul/epidemiologia , Displasia do Colo do Útero/diagnóstico , Metilação de DNA , Papillomaviridae/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genéticaRESUMO
The Josephson effect results from the coupling of two superconductors across a spacer such as an insulator, a normal metal or a ferromagnet to yield a phase coherent quantum state. However, in junctions with ferromagnetic spacers, very long-range Josephson effects have remained elusive. Here we demonstrate extremely long-range (micrometric) high-temperature (tens of kelvins) Josephson coupling across the half-metallic manganite La0.7Sr0.3MnO3 combined with the superconducting cuprate YBa2Cu3O7. These planar junctions, in addition to large critical currents, display the hallmarks of Josephson physics, such as critical current oscillations driven by magnetic flux quantization and quantum phase locking effects under microwave excitation (Shapiro steps). The latter display an anomalous doubling of the Josephson frequency predicted by several theories. In addition to its fundamental interest, the marriage between high-temperature, dissipationless quantum coherent transport and full spin polarization brings opportunities for the practical realization of superconducting spintronics, and opens new perspectives for quantum computing.
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BACKGROUND AND AIMS: Nonanastomotic biliary strictures (NAS) are a major cause of morbidity after orthotopic liver transplantation (OLT). Although ischemic injury of peribiliary glands (PBGs) and peribiliary vascular plexus during OLT has been associated with the later development of NAS, the exact underlying mechanisms remain unclear. We hypothesized that bile ducts of patients with NAS suffer from ongoing biliary hypoxia and lack of regeneration from PBG stem/progenitor cells. APPROACH AND RESULTS: Forty-two patients, requiring retransplantation for either NAS (n = 18), hepatic artery thrombosis (HAT; n = 13), or nonbiliary graft failure (controls; n = 11), were included in this study. Histomorphological analysis of perihilar bile ducts was performed to assess differences in markers of cell proliferation and differentiation in PBGs, microvascular density (MVD), and hypoxia. In addition, isolated human biliary tree stem cells (hBTSCs) were used to examine exo-metabolomics during in vitro differentiation toward mature cholangiocytes. Bile ducts of patients with NAS or HAT had significantly reduced indices of PBG mass, cellular proliferation and differentiation (mucus production, secretin receptor expression, and primary cilia), reduced MVD, and increased PBG apoptosis and hypoxia marker expression, compared to controls. Metabolomics of hBTSCs during in vitro differentiation toward cholangiocytes revealed a switch from a glycolytic to oxidative metabolism, indicating the need for oxygen. CONCLUSIONS: NAS are characterized by a microscopic phenotype of chronic biliary hypoxia attributed to loss of microvasculature, resulting in reduced proliferation and differentiation of PBG stem/progenitor cells into mature cholangiocytes. These findings suggest that persistent biliary hypoxia is a key mechanism underlying the development of NAS after OLT.
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Sistema Biliar , Colestase , Transplante de Fígado , Ductos Biliares , Constrição Patológica/etiologia , Humanos , HipóxiaRESUMO
The spin-orbit interaction in spin qubits enables spin-flip transitions, resulting in Rabi oscillations when an external microwave field is resonant with the qubit frequency. Here, we introduce an alternative driving mechanism mediated by the strong spin-orbit interactions in hole spin qubits, where a far-detuned oscillating field couples to the qubit phase. Phase-driving at radio frequencies, orders of magnitude slower than the microwave qubit frequency, induces highly nontrivial spin dynamics, violating the Rabi resonance condition. By using a qubit integrated in a silicon fin field-effect transistor, we demonstrate a controllable suppression of resonant Rabi oscillations and their revivals at tunable sidebands. These sidebands enable alternative qubit control schemes using global fields and local far-detuned pulses, facilitating the design of dense large-scale qubit architectures with local qubit addressability. Phase-driving also decouples Rabi oscillations from noise, an effect due to a gapped Floquet spectrum and can enable Floquet engineering high-fidelity gates in future quantum processors.
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Because the endogenous circadian pacemaker is a very strong determinant of alertness/sleep propensity across the 24 h period, its mistiming may contribute to symptoms of insomnia (e.g., difficulties initiating sleep and maintaining sleep) and to the development of insomnia disorder. Despite the separation of insomnia and circadian rhythm disorders in diagnostic nosology implying independent pathophysiology, there is considerable evidence of co-morbidity and interaction between them. Sleep onset insomnia is associated with later timed circadian rhythms and can be treated with morning bright light to shift rhythms to an earlier timing. It is also possible that the causal link may go in both directions and that having a delayed circadian rhythm can result in enough experiences of delayed sleep onset to lead to some conditioned insomnia or insomnia disorder further exacerbating a delayed circadian rhythm. Early morning awakening insomnia is associated with an advanced circadian phase (early timing) and can be treated with evening bright light resulting in a delay of rhythms and an improved ability to sleep later in the morning and to obtain more sleep. There is some evidence suggesting that sleep maintenance insomnia is associated with a blunted amplitude of circadian rhythm that may be treated with increased regularity of sleep and light exposure timing. However, this is an insomnia phenotype that requires considerably more circadian research as well as further insomnia clinical research with the other insomnia phenotypes incorporating circadian timing measures and treatments.