Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 7.594
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Nature ; 629(8012): 555-560, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38658758

RESUMO

The tokamak approach, utilizing a toroidal magnetic field configuration to confine a hot plasma, is one of the most promising designs for developing reactors that can exploit nuclear fusion to generate electrical energy1,2. To reach the goal of an economical reactor, most tokamak reactor designs3-10 simultaneously require reaching a plasma line-averaged density above an empirical limit-the so-called Greenwald density11-and attaining an energy confinement quality better than the standard high-confinement mode12,13. However, such an operating regime has never been verified in experiments. In addition, a long-standing challenge in the high-confinement mode has been the compatibility between a high-performance core and avoiding large, transient edge perturbations that can cause very high heat loads on the plasma-facing-components in tokamaks. Here we report the demonstration of stable tokamak plasmas with a line-averaged density approximately 20% above the Greenwald density and an energy confinement quality of approximately 50% better than the standard high-confinement mode, which was realized by taking advantage of the enhanced suppression of turbulent transport granted by high density-gradients in the high-poloidal-beta scenario14,15. Furthermore, our experimental results show an integration of very low edge transient perturbations with the high normalized density and confinement core. The operating regime we report supports some critical requirements in many fusion reactor designs all over the world and opens a potential avenue to an operating point for producing economically attractive fusion energy.

2.
Nature ; 601(7891): 49-52, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34987214

RESUMO

Magnetic fields have an important role in the evolution of interstellar medium and star formation1,2. As the only direct probe of interstellar field strength, credible Zeeman measurements remain sparse owing to the lack of suitable Zeeman probes, particularly for cold, molecular gas3. Here we report the detection of a magnetic field of +3.8 ± 0.3 microgauss through the H I narrow self-absorption (HINSA)4,5 towards L15446,7-a well-studied prototypical prestellar core in an early transition between starless and protostellar phases8-10 characterized by a high central number density11 and a low central temperature12. A combined analysis of the Zeeman measurements of quasar H I absorption, H I emission, OH emission and HINSA reveals a coherent magnetic field from the atomic cold neutral medium (CNM) to the molecular envelope. The molecular envelope traced by the HINSA is found to be magnetically supercritical, with a field strength comparable to that of the surrounding diffuse, magnetically subcritical CNM despite a large increase in density. The reduction of the magnetic flux relative to the mass, which is necessary for star formation, thus seems to have already happened during the transition from the diffuse CNM to the molecular gas traced by the HINSA. This is earlier than envisioned in the classical picture where magnetically supercritical cores capable of collapsing into stars form out of magnetically subcritical envelopes13,14.

3.
Nature ; 602(7896): 251-257, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35140390

RESUMO

The development of high-performance ultraelastic metals with superb strength, a large elastic strain limit and temperature-insensitive elastic modulus (Elinvar effect) are important for various industrial applications, from actuators and medical devices to high-precision instruments1,2. The elastic strain limit of bulk crystalline metals is usually less than 1 per cent, owing to dislocation easy gliding. Shape memory alloys3-including gum metals4,5 and strain glass alloys6,7-may attain an elastic strain limit up to several per cent, although this is the result of pseudo-elasticity and is accompanied by large energy dissipation3. Recently, chemically complex alloys, such as 'high-entropy' alloys8, have attracted tremendous research interest owing to their promising properties9-15. In this work we report on a chemically complex alloy with a large atomic size misfit usually unaffordable in conventional alloys. The alloy exhibits a high elastic strain limit (approximately 2 per cent) and a very low internal friction (less than 2 × 10-4) at room temperature. More interestingly, this alloy exhibits an extraordinary Elinvar effect, maintaining near-constant elastic modulus between room temperature and 627 degrees Celsius (900 kelvin), which is, to our knowledge, unmatched by the existing alloys hitherto reported.

4.
Nature ; 609(7928): 685-688, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36131036

RESUMO

Fast radio bursts (FRBs) are highly dispersed, millisecond-duration radio bursts1-3. Recent observations of a Galactic FRB4-8 suggest that at least some FRBs originate from magnetars, but the origin of cosmological FRBs is still not settled. Here we report the detection of 1,863 bursts in 82 h over 54 days from the repeating source FRB 20201124A (ref. 9). These observations show irregular short-time variation of the Faraday rotation measure (RM), which scrutinizes the density-weighted line-of-sight magnetic field strength, of individual bursts during the first 36 days, followed by a constant RM. We detected circular polarization in more than half of the burst sample, including one burst reaching a high fractional circular polarization of 75%. Oscillations in fractional linear and circular polarizations, as well as polarization angle as a function of wavelength, were detected. All of these features provide evidence for a complicated, dynamically evolving, magnetized immediate environment within about an astronomical unit (AU; Earth-Sun distance) of the source. Our optical observations of its Milky-Way-sized, metal-rich host galaxy10-12 show a barred spiral, with the FRB source residing in a low-stellar-density interarm region at an intermediate galactocentric distance. This environment is inconsistent with a young magnetar engine formed during an extreme explosion of a massive star that resulted in a long gamma-ray burst or superluminous supernova.

6.
Ann Oncol ; 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38964714

RESUMO

BACKGROUND: Neoadjuvant short-course radiotherapy (SCRT) followed by CAPOX and camrelizumab (a PD-1 monoclonal antibody) has shown potential clinical activity for locally advanced rectal cancer (LARC) in a phase II trial. This study aimed to further confirm the efficacy and safety of SCRT followed by CAPOX and camrelizumab compared to long-course chemoradiotherapy (LCRT) followed by CAPOX alone as neoadjuvant treatment for LARC. PATIENTS AND METHODS: In this randomized, phase III trial, patients with T3-4/N+ rectal adenocarcinoma were randomly assigned (1:1) to receive SCRT or long-course chemoradiotherapy (LCRT), followed by 2 cycles of camrelizumab and CAPOX or CAPOX alone, respectively. After surgery, each arm underwent either 6 cycles of camrelizumab and CAPOX, followed by up to 17 doses of camrelizumab, or 6 cycles of CAPOX. The primary endpoint was pathological complete response (pCR) rate (ypT0N0) assessed by a blinded independent review committee. Key secondary endpoints tested hierarchically were 3-year event-free survival (EFS) rate and overall survival (OS). RESULTS: Between July 2021 and March 2023, the intention-to-treat population comprised 113 patients in experimental arm and 118 patients in control arm, with surgery performed in 92% and 83.9%, respectively. At data cutoff (July 11, 2023), the pCR rate were 39.8% (95% CI, 30.7 to 49.5) in experimental arm compared to 15.3% (95% CI, 9.3 to 23.0) in control arm (difference, 24.6%; odds ratio, 3.7; 95% CI, 2.0 to 6.9; p < 0.001). In each arm, surgical complication rates were 40.0% and 40.8%, grade ≥ 3 treatment-related adverse events were 29.2% and 27.2%. 3-year EFS rate and OS continue to mature. CONCLUSIONS: In LARC patients, neoadjuvant SCRT followed by camrelizumab plus CAPOX demonstrated a significantly higher pCR rate than LCRT followed by CAPOX, with a well-tolerated safety profile. SCRT followed by camrelizumab and chemotherapy can be recommended as a neoadjuvant treatment modality for these patients.

7.
Small ; 20(11): e2309454, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38098368

RESUMO

The optimal treatment for tracheal tumors necessitates sequential tumor elimination and tracheal cartilage reconstruction. This study introduces an innovative inorganic nanosheet, MnO2 /PDA@Cu, comprising manganese dioxide (MnO2 ) loaded with copper ions (Cu) through in situ polymerization using polydopamine (PDA) as an intermediary. Additionally, a specialized methacrylic anhydride modified decellularized cartilage matrix (MDC) hydrogel with chondrogenic effects is developed by modifying a decellularized cartilage matrix with methacrylic anhydride. The MnO2 /PDA@Cu nanosheet is encapsulated within MDC-derived microneedles, creating a photothermal-controllable MnO2 /PDA@Cu-MDC microneedle. Effectiveness evaluation involved deep insertion of the MnO2 /PDA@Cu-MDC microneedle into tracheal orthotopic tumor in a murine model. Under 808 nm near-infrared irradiation, facilitated by PDA, the microneedle exhibited rapid overheating, efficiently eliminating tumors. PDA's photothermal effects triggered controlled MnO2 and Cu release. The MnO2 nanosheet acted as a potent inorganic nanoenzyme, scavenging reactive oxygen species for an antioxidant effect, while Cu facilitated angiogenesis. This intervention enhanced blood supply at the tumor excision site, promoting stem cell enrichment and nutrient provision. The MDC hydrogel played a pivotal role in creating a chondrogenic niche, fostering stem cells to secrete cartilaginous matrix. In conclusion, the MnO2 /PDA@Cu-MDC microneedle is a versatile platform with photothermal control, sequentially combining antitumor, antioxidant, pro-angiogenic, and chondrogenic activities to orchestrate precise tracheal tumor eradication and cartilage regeneration.


Assuntos
Nanopartículas , Neoplasias , Neoplasias da Traqueia , Humanos , Camundongos , Animais , Antioxidantes , Compostos de Manganês , Óxidos , Neoplasias/patologia , Cartilagem , Hidrogéis , Anidridos
8.
Phys Rev Lett ; 132(7): 072502, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38427897

RESUMO

Using the fusion-evaporation reaction ^{106}Cd(^{58}Ni,4n)^{160}Os and the gas-filled recoil separator SHANS, two new isotopes _{76}^{160}Os and _{74}^{156}W have been identified. The α decay of ^{160}Os, measured with an α-particle energy of 7080(26) keV and a half-life of 201_{-37}^{+58} µs, is assigned to originate from the ground state. The daughter nucleus ^{156}W is a ß^{+} emitter with a half-life of 291_{-61}^{+86} ms. The newly measured α-decay data allow us to derive α-decay reduced widths (δ^{2}) for the N=84 isotones up to osmium (Z=76), which are found to decrease with increasing atomic number above Z=68. The reduction of δ^{2} is interpreted as evidence for the strengthening of the N=82 shell closure toward the proton drip line, supported by the increase of the neutron-shell gaps predicted in theoretical models.

9.
Phys Rev Lett ; 132(17): 171001, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38728703

RESUMO

Recently a dark matter-electron (DM-electron) paradigm has drawn much attention. Models beyond the standard halo model describing DM accelerated by high energy celestial bodies are under intense examination as well. In this Letter, a velocity components analysis (VCA) method dedicated to swift analysis of accelerated DM-electron interactions via semiconductor detectors is proposed and the first HPGe detector-based accelerated DM-electron analysis is realized. Utilizing the method, the first germanium based constraint on sub-GeV solar reflected DM-electron interaction is presented with the 205.4 kg·day dataset from the CDEX-10 experiment. In the heavy mediator scenario, our result excels in the mass range of 5-15 keV/c^{2}, achieving a 3 orders of magnitude improvement comparing with previous semiconductor experiments. In the light mediator scenario, the strongest laboratory constraint for DM lighter than 0.1 MeV/c^{2} is presented. The result proves the feasibility and demonstrates the vast potential of the VCA technique in future accelerated DM-electron analyses with semiconductor detectors.

10.
Phys Rev Lett ; 132(15): 152503, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38682970

RESUMO

The first complete measurement of the ß-decay strength distribution of _{17}^{45}Cl_{28} was performed at the Facility for Rare Isotope Beams (FRIB) with the FRIB Decay Station Initiator during the second FRIB experiment. The measurement involved the detection of neutrons and γ rays in two focal planes of the FRIB Decay Station Initiator in a single experiment for the first time. This enabled an analytical consistency in extracting the ß-decay strength distribution over the large range of excitation energies, including neutron unbound states. We observe a rapid increase in the ß-decay strength distribution above the neutron separation energy in _{18}^{45}Ar_{27}. This was interpreted to be caused by the transitioning of neutrons into protons excited across the Z=20 shell gap. The SDPF-MU interaction with reduced shell gap best reproduced the data. The measurement demonstrates a new approach that is sensitive to the proton shell gap in neutron rich nuclei according to SDPF-MU calculations.

11.
Soft Matter ; 20(27): 5359-5366, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38913331

RESUMO

That a three-dimensional vesicle morphology can be modeled by an artificial neural network is proposed and demonstrated. In the phase-field representation, the Helfrich bending energy of a membrane is equivalently cast into field-based energy, which enables a more direct representation of a deformable, three-dimensional membrane surface. The core of our method is incorporating recent machine-learning techniques to perform the required energy minimization. The versatile ability of the method, to compute axisymmetric and nonsymmetric shapes, is discussed.

12.
Clin Radiol ; 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38849236

RESUMO

AIMS: The objective of our study was to establish and verify a novel combined model based on multiparameter magnetic resonance imaging (MRI) radiomics and clinical features to distinguish intraspinal schwannomas from meningiomas. MATERIALS AND METHODS: This research analyzed the preoperative magnetic resonance (MR) images and clinical characteristics of 209 patients with intraspinal tumors who received tumor resection at three institutions. 159 individuals from institutions 1 and 2 were randomly assigned into a training group (n=111) and a test group (n=48) in a 7-3 ratio. A nomogram was constructed using the training cohort and was internally and externally verified in the test cohort and an independent validation cohort (n=50). Model performance was assessed utilizing the area under the curve (AUC) of receiver operating characteristics (ROC), decision curve analysis (DCA), and calibration curves. RESULTS: The nomogram exhibited superior predictive efficacy in distinguishing between spinal schwannomas and meningiomas when compared to both the radiomics model and the clinical model. The nomogram yielded AUCs of 0.994, 0.962, and 0.949 in the training, test, and external validation cohorts, respectively, indicating its exceptional differentiating ability. The DCAs demonstrated that the nomogram yielded the best net benefit. The calibration curves indicated that the nomogram got good agreement between the predicted and the actual observation. CONCLUSION: This research suggests that the nomogram incorporating clinical and radiomic features may be an effective auxiliary tool for distinguishing between intraspinal schwannomas and meningiomas, and has important clinical significance for clinical decision-making and prognosis prediction.

13.
Clin Radiol ; 79(7): 544-552, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38599951

RESUMO

BACKGROUND: Left atrial (LA) dysfunction is involved in idiopathic inflammatory myopathy (IIM). Multiparametric cardiovascular magnetic resonance (CMR) strain imaging is a feasible and reproducible tool for examining global and regional LA functions, as well as left ventricular (LV) function in IIM patients. AIM: The aim of this study was to evaluate the feasibility and reproducibility of LA strain occurrence and strain rate for LA function assessment using CMR in IIM cases. MATERIALS AND METHODS: A total of 36 IIM and 42 healthy control cases were included. Baseline ventricular function was comparatively assessed in both groups. LA strain occurrence and strain rate were examined by cine cardiac magnetic resonance imaging [MRI] utilizing an in-house semiautomated technique. LA global function indexes were quantitated, including reservoir, conduit, and booster-pump functions. RESULTS: A total of 78 participants were enrolled in this study. There was no significant difference in left/right ventricular routine functions between IIM patients and control individuals (p>0.05); the same results (p>0.05) was also observed between patients with high hs-cTnI and normal. However, LV mass index had significant difference (p1=0.003, p2<0.01). Compared with IIM patients and control individuals, only total strain (εs) (p4=0.046) and passive strain (εe) (p4=0.002) showed significant difference, and in cases with high hs-cTnI and normal hs-cTnI, there are differences for εs (p3=0.012) and εe (p4=0.047). The strongest association was found between εe and LV ejection fraction (LVEF) (r=0.581, p<0.01). CONCLUSION: IIM cases have altered LA reservoir and conduit functions, and LA strain could reflect LA function.


Assuntos
Átrios do Coração , Imagem Cinética por Ressonância Magnética , Miosite , Humanos , Masculino , Feminino , Miosite/diagnóstico por imagem , Miosite/fisiopatologia , Imagem Cinética por Ressonância Magnética/métodos , Átrios do Coração/diagnóstico por imagem , Átrios do Coração/fisiopatologia , Adulto , Reprodutibilidade dos Testes , Pessoa de Meia-Idade , Função do Átrio Esquerdo/fisiologia , Estudos de Viabilidade , Estudos de Casos e Controles
14.
J Chem Phys ; 161(4)2024 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-39037136

RESUMO

Tetrahedral liquids exhibit intriguing thermodynamic and transport properties because of the various ways tetrahedra can be packed and connected. Recently, an unusual temperature dependence of the stretching exponent ß in a model tetrahedral liquid ZnCl2 from Tm + 85 K to Tm + 35 K has been reported using neutron-spin echo spectroscopy. This discovery stands in sharp contrast to other glass-forming liquids. In this study, we conducted neural network force field driven molecular dynamic simulations of ZnCl2. We found a non-monotonic temperature dependence of ß from liquid to supercooled liquid temperatures. Further structural decomposition and dynamic analysis suggest that this unusual dynamic behavior is a result of the competition between the decrease in the diversity of tetrahedra motifs (structural heterogeneity) and the increase in glassy dynamic heterogeneity. This result may contribute to new understandings of the structural relaxation of other network liquids.

15.
J Chem Phys ; 160(14)2024 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-38591676

RESUMO

Dimensionality reduction often serves as the first step toward a minimalist understanding of physical systems as well as the accelerated simulations of them. In particular, neural network-based nonlinear dimensionality reduction methods, such as autoencoders, have shown promising outcomes in uncovering collective variables (CVs). However, the physical meaning of these CVs remains largely elusive. In this work, we constructed a framework that (1) determines the optimal number of CVs needed to capture the essential molecular motions using an ensemble of hierarchical autoencoders and (2) provides topology-based interpretations to the autoencoder-learned CVs with Morse-Smale complex and sublevelset persistent homology. This approach was exemplified using a series of n-alkanes and can be regarded as a general, explainable nonlinear dimensionality reduction method.

16.
J Chem Phys ; 160(8)2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38385518

RESUMO

A semiflexible polymer can be stretched by either applying a force to it or by fixing the positions of its endpoints. The two approaches generally yield different results and correspond to experiments performed in either the Gibbs or Helmholtz statistical ensembles. Here, we derive the Helmholtz force-extension relationship for the commonly used wormlike-chain model in the strongly stretched regime. By analyzing it in comparison with the Gibbs ensemble result, we show that equivalence between the two relationships is achieved only in the long-chain thermodynamic limit.

17.
J Endocrinol Invest ; 47(6): 1467-1476, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38112910

RESUMO

BACKGROUND: Acne vulgaris is a prevalent skin condition. We have found that some acromegaly patients have acne. However, no study has examined the relationship between acromegaly and acne. OBJECTIVE: To explore prevalence and correlation of adult acne in patients with acromegaly. METHODS: For this cross-sectional study, we collected questionnaires, clinical information, and laboratory test results of acromegaly patients from January 2022 to December 2022 at Huashan Hospital. Of the 133 questionnaires returned, 123 had valid responses. RESULTS: Of the 123 patients with acromegaly enrolled in this study, 54.5% had adult acne. No statistically significant difference was found in prevalence between male and female patients. 61.2% of adult acne patients reported late-onset acne. Late-onset acne patients first developed acne years before acromegaly diagnosis (mean of 5.6 years for male and 4.5 years for female patients). Some acne patients have received traditional anti-acne treatment. Moreover, 31% of the patients reported no improvement, and only 3.5% of patients claimed complete resolution of acne after treatment. Before acromegaly treatment, the prevalence of adult acne was 51.2%, with mild acne accounting for 73.0%, moderate acne accounting for 23.8%, and severe acne accounting for 3.2%. After acromegaly treatment, the prevalence of adult acne was significantly decreased to 37.4% (P = 0.007). An overall decrease in acne severity was noted, with 93.5%, 6.5%, and 0% having mild, moderate, and severe acne, respectively. A total of 83.6% of the patients had self-assessed acne remission, and 33.3% of the patients reported complete acne resolution. However, 9.0% of patients reported that their condition had worsened after acromegaly treatment. After treatment, GH, IGF-1, IGF-1 index, insulin levels, and HOMA-IR decreased significantly in all patients with acromegaly (P < 0.05). Acne remission correlated positively with IGF-1 levels, but not with GH levels. The relationship between acromegaly and acne remains to be elucidated. CONCLUSIONS: Our findings provide preliminary evidence of the high prevalence of adult acne in acromegaly patients, and a high rate of late-onset acne as well. Traditional anti-acne treatments are less effective. Acne could be considerably relieved by treating acromegaly. Acne remission positively correlated with IGF-1 decline as well, which revealed the correlation between acne and IGF-1.


Assuntos
Acne Vulgar , Acromegalia , Humanos , Acne Vulgar/epidemiologia , Acromegalia/epidemiologia , Acromegalia/sangue , Acromegalia/terapia , Acromegalia/complicações , Masculino , Feminino , Estudos Transversais , Adulto , Estudos Retrospectivos , Prevalência , Pessoa de Meia-Idade , Adulto Jovem , Idoso
18.
Artif Organs ; 48(1): 6-15, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38013239

RESUMO

Patients with advanced ischemic cardiomyopathy manifesting as left ventricular dysfunction exist along a spectrum of severity and risk, and thus decision-making surrounding optimal management is challenging. Treatment pathways can include medical therapy as well as revascularization through percutaneous coronary intervention or coronary artery bypass grafting. Additionally, temporary and durable mechanical circulatory support, as well as heart transplantation, may be optimal for select patients. Given this spectrum of risk and the complexity of treatment pathways, patients may not receive appropriate therapy given their perceived risk, which can lead to sub-satisfactory outcomes. In this review, we discuss the identification of high-risk ischemic cardiomyopathy patients, along with our programmatic approach to patient evaluation and perioperative optimization. We also discuss our strategies for therapeutic decision-making designed to optimize both short- and long-term patient outcomes.


Assuntos
Cardiomiopatias , Isquemia Miocárdica , Intervenção Coronária Percutânea , Disfunção Ventricular Esquerda , Humanos , Isquemia Miocárdica/complicações , Isquemia Miocárdica/terapia , Ponte de Artéria Coronária , Disfunção Ventricular Esquerda/cirurgia , Cardiomiopatias/terapia , Cardiomiopatias/cirurgia , Resultado do Tratamento
19.
Proc Natl Acad Sci U S A ; 118(11)2021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33836583

RESUMO

Apparent critical phenomena, typically indicated by growing correlation lengths and dynamical slowing down, are ubiquitous in nonequilibrium systems such as supercooled liquids, amorphous solids, active matter, and spin glasses. It is often challenging to determine if such observations are related to a true second-order phase transition as in the equilibrium case or simply a crossover and even more so to measure the associated critical exponents. Here we show that the simulation results of a hard-sphere glass in three dimensions are consistent with the recent theoretical prediction of a Gardner transition, a continuous nonequilibrium phase transition. Using a hybrid molecular simulation-machine learning approach, we obtain scaling laws for both finite-size and aging effects and determine the critical exponents that traditional methods fail to estimate. Our study provides an approach that is useful to understand the nature of glass transitions and can be generalized to analyze other nonequilibrium phase transitions.

20.
Rhinology ; 62(2): 236-249, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38085113

RESUMO

BACKGROUND: Vitamin D (VD) possesses immunomodulatory properties, but its role in chronic rhinosinusitis with nasal polyps (CRSwNP) remains poorly studied. Herein, we aim to explore the regulation and function of VD3 in CRSwNP. METHODS: 25-hydroxyvitamin D3 (25VD3) levels in serum and tissue lysates were detected by ELISA. The expression of VD receptor (VDR) and cytochrome P450 family 27 subfamily B member 1 (CYP27B1), the enzyme that converts 25VD3 to the active 1,25-hydroxyvitamin D3 (1,25VD3), and their expression regulation in human nasal epithelial cells (HNECs) were studied by RT-PCR, western blotting, immunofluorescence, and flow cytometry. RNA sequencing was performed to identify genes regulated by 1,25VD3 in HNECs. HNECs and polyp tissue explants were treated with 1,25VD3, 25VD3, and dexamethasone. RESULTS: 25VD3 levels in serum and nasal tissue lysates were decreased in patients with eosinophilic and noneosinophilic CRSwNP than control subjects. The expression of VDR and CYP27B1 were reduced in eosinophilic and noneosinophilic CRSwNP, particularly in nasal epithelial cells. VDR and CYP27B1 expression in HNECs were downregulated by interferon y and poly (I:C). Polyp-derived epithelial cells demonstrated an impaired ability to convert 25VD3 to 1,25VD3 than control tissues. 1,25VD3 and 25VD3 suppressed IL-36y production in HNECs and polyp tissues, and the effect of 25VD3 was abolished by siCYP27B1 treatment. Tissue 25VD3 levels negatively correlated with IL-36y expression and neutrophilic inflammation in CRSwNP. CONCLUSION: Reduced systemic 25VD3 level, local 1,25VD3 generation and VDR expression result in impaired VD3 signaling activation in nasal epithelial cells, thereby exaggerating IL-36y production and neutrophilic inflammation in CRSwNP.


Assuntos
Pólipos Nasais , Rinite , Rinossinusite , Sinusite , Humanos , Sinusite/metabolismo , Pólipos Nasais/complicações , Pólipos Nasais/metabolismo , Rinite/metabolismo , Calcifediol/metabolismo , Calcifediol/farmacologia , 25-Hidroxivitamina D3 1-alfa-Hidroxilase/metabolismo , 25-Hidroxivitamina D3 1-alfa-Hidroxilase/farmacologia , Inflamação , Células Epiteliais/metabolismo , Doença Crônica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA