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1.
FASEB J ; 38(3): e23449, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38315451

RESUMO

Adipose tissue is the second most important site of estrogen production, where androgens are converted into estrogen by aromatase. While gastric cancer patients often develop adipocyte-rich peritoneal metastasis, the underlying mechanism remains unclear. In this study, we identified the G-protein-coupled estrogen receptor (GPER1) as a promoter of gastric cancer peritoneal metastasis. Functional in vitro studies revealed that ß-Estradiol (E2) or the GPER1 agonist G1 inhibited anoikis in gastric cancer cells. Additionally, genetic overexpression or knockout of GPER1 significantly inhibited or enhanced gastric cancer cell anoikis in vitro and peritoneal metastasis in vivo, respectively. Mechanically, GPER1 knockout disrupted the NADPH pool and increased reactive oxygen species (ROS) generation. Conversely, overexpression of GPER1 had the opposite effects. GPER1 suppressed nicotinamide adenine dinucleotide kinase 1(NADK1) ubiquitination and promoted its phosphorylation, which were responsible for the elevated expression of NADK1 at protein levels and activity, respectively. Moreover, genetic inhibition of NADK1 disrupted NADPH and redox homeostasis, leading to high levels of ROS and significant anoikis, which inhibited lung and peritoneal metastasis in cell-based xenograft models. In summary, our study suggests that inhibiting GPER1-mediated NADK1 activity and its ubiquitination may be a promising therapeutic strategy for peritoneal metastasis of gastric cancer.


Assuntos
Neoplasias Peritoneais , Receptores de Estrogênio , Receptores Acoplados a Proteínas G , Neoplasias Gástricas , Humanos , Estrogênios/metabolismo , NAD/metabolismo , NADP/metabolismo , Oxirredução , Neoplasias Peritoneais/secundário , Espécies Reativas de Oxigênio/metabolismo , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Neoplasias Gástricas/patologia , Animais
2.
J Nutr ; 154(2): 526-534, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38072155

RESUMO

BACKGROUND: Chronic constipation (CC) is a common gut health problem, and the role of live dietary microbes in CC is unclear. OBJECTIVE: This study aimed to investigate the relationship between dietary live microbes consumption and CC. METHODS: Using the National Health and Nutrition Examination Survey data (2005-2010), 11,170 adults who completed the 24-h face-to-face dietary recall and bowel health questionnaire were identified. CC was defined by the Bristol Stool Form Scale. Dietary live microbes intake was classified as low, medium, and high. Additionally, combined medium and high categories (MedHi) were analyzed. Multivariate regression models were constructed to assess the association between dietary intake of live microbes and CC. RESULTS: In the weighted sample, the age-adjusted CC prevalence was 7.06% (95% confidence interval [CI]: 6.45, 7.67). In multivariate regression models, after controlling for potential confounders race/ethnicity, sex, body mass index, education, poverty, depression, caffeine intake, and alcohol intake, a significant inverse association between dietary live microbes consumption and CC was observed (odds ratio [OR]: 0.77, 95% CI: 0.61, 0.97, P-trend = 0.061). CONCLUSIONS: Our findings suggest that a high dietary live microbes consumption may be associated with lower odds of CC. However, further prospective studies are essential to confirm its effectiveness in reducing CC occurrence.


Assuntos
Constipação Intestinal , Dieta , Adulto , Humanos , Inquéritos Nutricionais , Estudos Prospectivos , Constipação Intestinal/epidemiologia , Ingestão de Alimentos
3.
Molecules ; 29(6)2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38542887

RESUMO

Herein, a Sc(OTf)3-catalyzed (3+2) annulation of 2-indolylmethanols with propargylic alcohols is reported. The reaction proceeds via a Friedel-Crafts-type allenylation/5-exo-annulation cascade. In the reaction, 2-indolylmethanol is used as a three-carbon synthon, and propargyl alcohol is used as a two-carbon synthon. This method provides a direct and high-yield pathway for synthetically useful cyclopenta[b]indoles. In general, the method features easily accessible substrates with broad scope and generality, the formation of multiple bonds with high efficiency, and easy scale-up.

4.
Phys Rev Lett ; 130(14): 143201, 2023 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-37084454

RESUMO

Searching for beyond-the-standard-model interactions has been of interest in quantum sensing. Here, we demonstrate a method, both theoretically and experimentally, to search for the spin- and velocity-dependent interaction with an atomic magnetometer at the centimeter scale. By probing the diffused optically polarized atoms, undesirable effects coming along with the optical pumping, such as light shifts and power-broadening effects, are suppressed, which enables a 1.4 fT_{rms}/Hz^{1/2} noise floor and the reduced systematic errors of the atomic magnetometer. Our method sets the most stringent laboratory experiment constraints on the coupling strength between electrons and nucleons for the force range λ>0.7 mm at 1σ confidence. The limit is more than 3 orders of magnitude tighter than the previous constraints for the force range between 1 mm∼10 mm, and one order of magnitude tighter for the force range above 10 mm.

5.
J Biol Chem ; 296: 100497, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33675752

RESUMO

The CRISPR/Cas9 system has been used in a wide range of applications in the production of gene-edited animals and plants. Most efforts to insert genes have relied on homology-directed repair (HDR)-mediated integration, but this strategy remains inefficient for the production of gene-edited livestock, especially monotocous species such as cattle. Although efforts have been made to improve HDR efficiency, other strategies have also been proposed to circumvent these challenges. Here we demonstrate that a homology-mediated end-joining (HMEJ)-based method can be used to create gene-edited cattle that displays precise integration of a functional gene at the ROSA26 locus. We found that the HMEJ-based method increased the knock-in efficiency of reporter genes by eightfold relative to the traditional HDR-based method in bovine fetal fibroblasts. Moreover, we identified the bovine homology of the mouse Rosa26 locus that is an accepted genomic safe harbor and produced three live-born gene-edited cattle with higher rates of pregnancy and birth, compared with previous work. These gene-edited cattle exhibited predictable expression of the functional gene natural resistance-associated macrophage protein-1 (NRAMP1), a metal ion transporter that should and, in our experiments does, increase resistance to bovine tuberculosis, one of the most detrimental zoonotic diseases. This research contributes to the establishment of a safe and efficient genome editing system and provides insights for gene-edited animal breeding.


Assuntos
Bovinos/genética , Clonagem de Organismos , Resistência à Doença , Edição de Genes , Loci Gênicos , Tuberculose Bovina/genética , Animais , Bovinos/microbiologia , Reparo do DNA por Junção de Extremidades , Tuberculose Bovina/metabolismo
6.
Exp Cell Res ; 399(2): 112421, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33412164

RESUMO

Postovulatory oocyte aging has a major influence on the development potential of embryos. Many antioxidants can delay oocyte aging by regulating the expression of SIRT1. However, there is a lack of knowledge on SIRT1 function in postovulatory oocyte aging. In vitro transcribed RNA of Sirt1 was injected into fresh oocytes to investigate the function of SIRT1 during postovulatory oocyte aging. In the present study, SIRT1 was found to be down-regulated in aged oocytes compared with fresh oocytes. Meanwhile the intensity of acetylation of H3K9 (H3K9ac) and H3K4 methylation increased in postovulatory aged oocytes. After the oocytes were injected with SIRT1 and aged for 12 h, the intensity of H3K9ac and H3K4 methylation markedly decreased compared with controls. Furthermore, SIRT1 overexpression also reduced the aging-induced oocyte morphological changes and reactive oxygen species accumulation, maintained the spindle normal morphology and attenuated the aging-associated abnormalities of mitochondrial function. The role of SIRT1 in protecting oocyte aging was diminished when oocytes with overexpressed SIRT1 were cultured with SIRT1 inhibitor EX-527. Briefly, these present results show that SIRT1 not only reduced the non-epigenetic changes such as abnormal oocyte morphology, ROS accumulation, spindle defects and mitochondrial dysfunctions but also regulated the epigenetic changes in order to maintain the quality of postovulatory aged oocytes.


Assuntos
Senescência Celular/genética , Epigênese Genética/genética , Oócitos/fisiologia , Sirtuína 1/fisiologia , Acetilação , Animais , Antioxidantes/metabolismo , Células Cultivadas , Metilação de DNA/genética , Feminino , Histona Acetiltransferases/metabolismo , Histonas/metabolismo , Camundongos , Camundongos Endogâmicos ICR , Oócitos/citologia , Ovulação/fisiologia , Espécies Reativas de Oxigênio/metabolismo
7.
Sensors (Basel) ; 22(14)2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35890956

RESUMO

Sixth-generation (6G) wireless communication scenarios are complex and diverse. Small-scale fading is a key part of wireless channels and its impact on performance in scenarios with time sensitivity and 6G ultrareliable and low latency communications (URLLC) quality-of-service requirements cannot be ignored. Therefore, it is necessary to accurately characterize small-scale fading when designing wireless communication systems. In this paper, we derive approximate closed form expressions for the probability density function, cumulative distribution function and moment-generating function of the postprocessing signal-to-noise ratio following the zero-forcing detector in a cell-free massive multiple-input multiple-output (CF mMIMO) system. CF mMIMO system is a nonorthogonal multiple access (NOMA) system that enables users to share all channel uses and can ensure the fairness of the communication quality experienced by different users. Our key contributions include the extension of the κ-µ shadowed fading model to a CF mMIMO system and the proposal of theoretical tools (the derived closed-form expression) to improve its mathematical tractability. By exploiting the statistical characterizations of the arrival and service processes, another important contribution is the exploitation of the upper bound of the queuing delay violation probability (UB-QDVP) over the Mellin transforms of the arrival and service processes in the proposed CF mMIMO system under the κ-µ shadowed fading model. Corroborated by extensive simulations, our analyses validate that the CF mMIMO system outperforms the orthogonal multiple access and power-domain NOMA systems and reveal the relationships among different small-scale fading types, energy efficiency, delay and the UB-QDVP, as well as the accuracy and effectiveness of the proposed theoretical tools based on the κ-µ shadowed fading model.

8.
Stem Cells ; 38(2): 218-230, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31648394

RESUMO

Huntington's disease (HD) is a neurodegenerative disorder caused by a mutation in the huntingtin (HTT) gene that results in the production of neurotoxic mutant HTT (mHTT) protein. Suppressing HTT production with antisense oligonucleotides (ASOs) is a promising treatment strategy for HD; however, the difficulty of delivering ASOs to deep brain structures is a major barrier for its clinical application. The glymphatic system of astrocytes involving aquaporin 4 (AQP-4) controls the entry of macromolecules from the cerebrospinal fluid into the brain. Mesenchymal stem cells (MSCs) target astrocytes to inhibit neuroinflammation. Here we examined the glymphatic distribution of ASO in the brain and the therapeutic potential of combining intravenously injection of mesenchymal stem cells (IV-MSC) and ASOs for the treatment of HD. Our results show that Cy3-labeled ASOs entered the brain parenchyma via the perivascular space following cisternal injection, but the brain distribution was significantly lower in AQP-4-/- as compared with wild-type mice. Downregulation of the AQP-4 M23 isoform was accompanied by decreased brain levels of ASOs in BACHD mice as well as an increase in astrogliosis and phosphorylation of nuclear factor κB (NF-κB) p65. IV-MSC treatment restored AQP-4 M23 expression, attenuated astrogliosis, and decreased NF-κB p65 phosphorylation; it also increased the brain distribution of ASOs and enhanced the suppression of mHTT in BACHD mice. These results suggest that modulating glymphatic activity using IV-MSC is a novel strategy for improving the potency of ASO in the treatment of HD.


Assuntos
Aquaporina 4/metabolismo , Doença de Huntington/genética , Células-Tronco Mesenquimais/metabolismo , Oligonucleotídeos Antissenso/genética , Adulto , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Pessoa de Meia-Idade
9.
Phys Rev Lett ; 126(14): 141802, 2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33891466

RESUMO

We report the results of an experimental search for ultralight axionlike dark matter in the mass range 162-166 neV. The detection scheme of our Cosmic Axion Spin Precession Experiment is based on a precision measurement of ^{207}Pb solid-state nuclear magnetic resonance in a polarized ferroelectric crystal. Axionlike dark matter can exert an oscillating torque on ^{207}Pb nuclear spins via the electric dipole moment coupling g_{d} or via the gradient coupling g_{aNN}. We calibrate the detector and characterize the excitation spectrum and relaxation parameters of the nuclear spin ensemble with pulsed magnetic resonance measurements in a 4.4 T magnetic field. We sweep the magnetic field near this value and search for axionlike dark matter with Compton frequency within a 1 MHz band centered at 39.65 MHz. Our measurements place the upper bounds |g_{d}|<9.5×10^{-4} GeV^{-2} and |g_{aNN}|<2.8×10^{-1} GeV^{-1} (95% confidence level) in this frequency range. The constraint on g_{d} corresponds to an upper bound of 1.0×10^{-21} e cm on the amplitude of oscillations of the neutron electric dipole moment and 4.3×10^{-6} on the amplitude of oscillations of CP-violating θ parameter of quantum chromodynamics. Our results demonstrate the feasibility of using solid-state nuclear magnetic resonance to search for axionlike dark matter in the neV mass range.

10.
J Surg Oncol ; 124(8): 1442-1450, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34494280

RESUMO

BACKGROUND AND OBJECTIVES: This study aimed to compare outcomes between neoadjuvant imatinib and upfront surgery in patients with localized rectal gastrointestinal stromal tumors (GIST) patients. METHODS: Eighty-five patients with localized rectal GIST were divided into two groups: upfront surgery ± adjuvant imatinib (Group A, n = 33) and the neoadjuvant imatinib + surgery + adjuvant imatinib (Group B, n = 52). Baseline characteristics between groups were controlled for with inverse probability of treatment weighting (IPTW) adjusted analysis. RESULTS: The response rate to neoadjuvant imatinib was 65.9%. After the IPTW-adjusted analysis, patients who underwent neoadjuvant therapy had better distant recurrence-free survival (DRFS) and disease-specific survival (DSS) compared with those who underwent upfront surgery (5-year DRFS 97.8 vs. 71.9%, hazard ratio [HR], 0.15; 95% CI, 0.03-0.87; p = 0.03; 5-year DSS 100 vs. 77.1%; HR, 0.11; 95% CI, 0.01-0.92; p = 0.04). While no significant association was found between overall survival (OS) and treatment groups (p = 0.07), 5-year OS was higher for the neoadjuvant group than upfront surgery group (97.8% vs. 71.9%; HR, 0.2; 95% CI, 0.03-1.15). CONCLUSIONS: In patients with localized rectal GIST, neoadjuvant imatinib not only shrunk the tumor size but also decreased the risk of metastasis and tumor-related deaths when compared to upfront surgery and adjuvant imatinib alone.


Assuntos
Antineoplásicos/uso terapêutico , Procedimentos Cirúrgicos do Sistema Digestório/mortalidade , Neoplasias Gastrointestinais/patologia , Tumores do Estroma Gastrointestinal/patologia , Mesilato de Imatinib/uso terapêutico , Terapia Neoadjuvante/mortalidade , Idoso , Estudos de Casos e Controles , Terapia Combinada , Feminino , Seguimentos , Neoplasias Gastrointestinais/tratamento farmacológico , Neoplasias Gastrointestinais/cirurgia , Tumores do Estroma Gastrointestinal/tratamento farmacológico , Tumores do Estroma Gastrointestinal/cirurgia , Humanos , Masculino , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida
11.
Surg Endosc ; 35(5): 2134-2143, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-32410082

RESUMO

AIM: The impact of pelvis on the development of anastomotic leak (AL) in rectal cancer (RC) patients who underwent anterior resection (AR) remains unclear. The aim of this study was to evaluate the impact of pelvic dimensions on the risk of AL. METHODS: A total of 1058 RC patients undergoing AR from January 2013 to January 2016 were enrolled. Pelvimetric parameters were obtained using abdominopelvic computed tomography scans. RESULTS: Univariate analyses showed that pelvic inlet, pelvic outlet, interspinous distance, and intertuberous distance were significantly associated with the risk for AL (P < 0.05). Multivariate analysis confirmed that pelvic inlet and intertuberous distance were independent risk factors for AL (P < 0.05). Significant factors from multivariate analysis were assembled into the nomogram A (without pelvic dimensions) and nomogram B (with pelvic dimensions). The area under curve (AUC) of nomogram B was 0.72 (95% CI 0.67-0.77), which was better than the AUC of nomogram A (0.69, [95% CI 0.65-0.74]), but didn't reach a statistical significance (P = 0.199). Decision curve supported that nomogram B was better than nomogram A. CONCLUSION: Pelvic dimensions, specifically pelvic inlet and intertuberous distance, seemed to be independent predictors for postoperative AL in RC patients. Pelvic inlet and intertuberous distance incorporated with preoperative radiotherapy, preoperative albumin, conversion, and tumor diameter in the nomogram might provide a clinical tool for predicting AL.


Assuntos
Fístula Anastomótica/etiologia , Procedimentos Cirúrgicos do Sistema Digestório/efeitos adversos , Pelve/anatomia & histologia , Neoplasias Retais/cirurgia , Idoso , Procedimentos Cirúrgicos do Sistema Digestório/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Nomogramas , Pelvimetria/métodos , Pelve/diagnóstico por imagem , Fatores de Risco , Tomografia Computadorizada por Raios X
12.
Magn Reson Chem ; 59(12): 1208-1215, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-33826170

RESUMO

Signal amplification by reversible exchange (SABRE) boosts NMR signals of various nuclei enabling new applications spanning from magnetic resonance imaging to analytical chemistry and fundamental physics. SABRE is especially well positioned for continuous generation of enhanced magnetization on a large scale; however, several challenges need to be addressed for accomplishing this goal. Specifically, SABRE requires (i) a specialized catalyst capable of reversible H2 activation and (ii) physical transfer of the sample from the point of magnetization generation to the point of detection (e.g., a high-field or a benchtop nuclear magnetic resonance [NMR] spectrometer). Moreover, (iii) continuous parahydrogen bubbling accelerates solvent (e.g., methanol) evaporation, thereby limiting the experimental window to tens of minutes per sample. In this work, we demonstrate a strategy to rapidly generate the best-to-date precatalyst (a compound that is chemically modified in the course of the reaction to yield the catalyst) for SABRE, [Ir(IMes)(COD)Cl] (IMes = 1,3-bis-[2,4,6-trimethylphenyl]-imidazol-2-ylidene; COD = cyclooctadiene) via a highly accessible synthesis. Second, we measure hyperpolarized samples using a home-built zero-field NMR spectrometer and study the field dependence of hyperpolarization directly in the detection apparatus, eliminating the need to physically move the sample during the experiment. Finally, we prolong the measurement time and reduce evaporation by presaturating parahydrogen with the solvent vapor before bubbling into the sample. These advancements extend opportunities for exploring SABRE hyperpolarization by researchers from various fields and pave the way to producing large quantities of hyperpolarized material for long-lasting detection of SABRE-derived nuclear magnetization.


Assuntos
Imageamento por Ressonância Magnética , Catálise , Espectroscopia de Ressonância Magnética
13.
Opt Express ; 28(10): 15081-15089, 2020 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-32403541

RESUMO

An all-optical self-oscillating 4He atomic magnetometer with a large dynamic range of the magnetic field is demonstrated. This device has the advantage of the fast response of the self-oscillating magnetometer and is not affected by the systematic errors originated from the radio-frequency field. It is also free from the nonlinear Zeeman effect in large magnetic fields. We use a liquid crystal to adjust the phase shift, which is independent of frequency. Results show that our self-oscillating 4He magnetometer exhibits a response time of 0.2 ms for a step signal of 3600 nT, and the noise floor reaches 1.7 pT / Hz1/2 for frequencies from 2 Hz to 500 Hz. It can work stably in magnetic fields ranging from 2500 nT to 103000 nT. Compared with the commercial self-oscillating cesium atomic magnetometer (Scintrex, CS-3), the self-oscillating 4He atomic magnetometer has shown a better gradient tolerance in larger magnetic field. This magnetometer is ideally suited in magnetic observatories to monitor geomagnetic field requiring large dynamic range and high bandwidth.

14.
Opt Express ; 28(26): 39400-39412, 2020 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-33379490

RESUMO

We demonstrate a sub-ps resolution clock-offset measurement based on linear optical sampling technique via a 114 km fiber link by transferring a dual optical frequency comb. The time deviation between two distance clocks is 110 fs at 1 s and 22 fs at 100 s averaging, and the standard deviation of the measured clock offset is 237 fs. This sub-ps level of clock offset measurement should benefit many time synchronization applications via long fiber links.

15.
Reproduction ; 159(1): 91-104, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31721723

RESUMO

Coactivator-associated arginine methyltransferase 1 (CARM1) is a type I arginine methyltransferase that methylates the arginine residues of histone and nonhistone. Carm1 regulates various cellular processes, including transcriptional regulation, mRNA processing, cellular proliferation, and differentiation. Blastomeres with high Carm1 expression levels show cleavage tendency to inner cell mass (ICM) in mouse embryos. However, details about the factors for CARM1 distribution in mouse early embryos and the role of Carm1 in blastocyst development remain unclear. Here, the endonuclear distribution of CARM1 protein was heterogeneous between blastomeres from the late four-cell stage to the blastocyst stage. The heterogeneity of CARM1 distribution in blastomeres at the late four-cell stage was randomly obtained from two-cell stage embryos. From the four-cell stage to morula, CARM1 in individual blastomere remained heterogeneous. In the blastocyst stage, CARM1 protein level in ICM was much higher than that in trophoblast. We found that microRNA (miRNA) miR-181a is an important regulator for Carm1 distribution at the late four-cell stage. The ratio of heterogeneous embryos was reduced in all the embryos when miR-181a was inhibited. CARM1 inhibition reduced the level of symmetrical histone H3 arginine-26 dimethylation and impaired blastocyst development. Silencing Carm1 reduced cell number and increased cell apoptosis at the blastocyst stage. These results show a CARM1 heterogeneous distribution from the four-cell embryos to the blastocysts. miR-181a regulates the control of CARM1 heterogeneous distribution in the four-cell-stage embryos, and CARM1 is an important protein in regulating blastocyst development.


Assuntos
Blastocisto/metabolismo , Blastômeros/metabolismo , Embrião de Mamíferos/metabolismo , Desenvolvimento Embrionário , Regulação da Expressão Gênica no Desenvolvimento , Proteína-Arginina N-Metiltransferases/metabolismo , Animais , Blastocisto/citologia , Blastômeros/citologia , Diferenciação Celular , Metilação de DNA , Embrião de Mamíferos/citologia , Feminino , Histonas/genética , Histonas/metabolismo , Camundongos , Proteína-Arginina N-Metiltransferases/genética
16.
Sensors (Basel) ; 20(4)2020 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-32102308

RESUMO

This study carries out a detailed full-scale investigation on the strong wind characteristics at a cable-stayed bridge site and associated buffeting response of the bridge structure during construction, using a field monitoring system. It is found that the wind turbulence parameters during the typhoon and monsoon conditions share a considerable amount of similarity, and they can be described as the input turbulence parameters for the current wind-induced vibration theory. While the longitudinal turbulence integral scales are consistent with those in regional structural codes, the turbulence intensities and gust factors are less than the recommended values. The wind spectra obtained via the field measurements can be well approximated by the von Karman spectra. For the buffeting response of the bridge under strong winds, its vertical acceleration responses at the extreme single-cantilever state are significantly larger than those in the horizontal direction and the increasing tendencies with mean wind velocities are also different from each other. The identified frequencies of the bridge are utilized to validate its finite element model (FEM), and these field-measurement acceleration results are compared with those from the FEM-based numerical buffeting analysis with measured turbulence parameters.

17.
Sensors (Basel) ; 20(15)2020 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-32751508

RESUMO

A magnetically-quiet environment is important for detecting faint magnetic-field signals or nonmagnetic spin-dependent interactions. Passive magnetic shielding using layers of large magnetic-permeability materials is widely used to reduce the magnetic-field noise. The magnetic-field noise can also be actively monitored with magnetometers and then compensated, acting as a complementary method to the passive shielding. We present here a general model to quantitatively depict and optimize the performance of active magnetic-field stabilization and experimentally verify our model using optically-pumped atomic magnetometers. We experimentally demonstrate a magnetic-field noise rejection ratio of larger than ∼800 at low frequencies and an environment with a magnetic-field noise floor of ∼40 fT/Hz1/2 in unshielded Earth's field. The proposed model provides a general guidance on analyzing and improving the performance of active magnetic-field stabilization with magnetometers. This work offers the possibility of sensitive detections of magnetic-field signals in a variety of unshielded natural environments.

18.
Sheng Li Xue Bao ; 72(2): 139-147, 2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-32328607

RESUMO

Increasing evidence suggests that stress may induce changes in hair color, with the underlying mechanism incompletely understood. In this study, female C57BL/6 mice subjected to electric foot shock combined with restraint stress were used to build chronic stress mouse model. The melanin contents and tyrosinase activity were measured in mouse skin and B16F10 melanoma cells. The enzyme-linked immunosorbent assay (ELISA) was used to determine the content of tumor necrosis factor α (TNF-α), interleukin- 1ß (IL-1ß) and interleukin-6 (IL-6) in the mouse skin. The content of nuclear factor κB (NFκB)/p65 subunit in mouse skins was valued by immunofluorescence staining. The results demonstrated that under chronic stress, the fur color turned from dark to brown in C57BL/6 mice due to the decrease of follicle melanocytes and tyrosinase activity in C57BL/6 mouse skin. Simultaneously, inflammatory responses in skins were detected as shown by increased NFκB activity and TNF-α expression in stressed mouse skin. In cultured B16F10 melanoma cells, TNF-α reduced the melanogenesis and tyrosinase activity in a dose-dependent manner. These findings indicate that chronic stress induces fur color change by decreasing follicle melanocytes and tyrosinase activity in female C57BL/6 mice, and TNF-α may play an important role in stress-induced hair color change.


Assuntos
Pelo Animal , Melanócitos/enzimologia , Monofenol Mono-Oxigenase/metabolismo , Pele/fisiopatologia , Estresse Fisiológico , Animais , Cor , Feminino , Melaninas , Melanoma Experimental , Camundongos , Camundongos Endogâmicos C57BL , Pigmentação
19.
J Xray Sci Technol ; 28(2): 231-241, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31929131

RESUMO

PURPOSE: To explore whether volumetric measurements of 3D-CUBE sequences based on baseline and early treatment time can predict neoadjuvent chemotherapy (NCT) efficacy of locally advanced rectal cancer (LARC). MATERIAL AND METHOD: 73 patients with LARC were enrolled from February 2014 to January 2018. All patients underwent MRIs during the baseline period before NCT (BL-NCT) and the first month of NCT (FM-NCT), and tumor volume (TV) was measured using 3D-CUBE, and tumor volume reduction (TVR) and tumor volume reduction rate (TVRR) were calculated. In addition, tumor invasion depth, tumor maximal length, range of tumor involvement in the circumference of intestinal lumen and distance from inferior part of tumor to the anal verge were measured using baseline high-spatial-resolution T2-weighted MRIs. All patients were categorized into sensitive and insensitive groups based on post-surgical pathology after completion of the full courses of NCT. The receiver operating characteristic (ROC) curve was used to analyze the value of different MRI parameters in predicting efficacy of NCT. RESULTS: Statistically significant differences in TV of BL-NCT, TVR and TVRR from BL-NCT to FM-NCT were detected between sensitive and insensitive groups (P < 0.05, respectively). The areas under the curves (AUC) of ROC of TVR and TVRR in predicting efficacy of NCT (0.890 [95% CI, 0.795∼0.951], 0.839 [95% CI, 0.735∼0.915]) were significantly better than that of TV (0.660 [95% CI, 0.540∼0.767]) (P < 0.05, respectively). CONCLUSION: Reconstruction of 3D-CUBE volume in the first month of NCT is necessary, and both TVR and TVRR can be used as early predictors of NCT efficacy.


Assuntos
Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Terapia Neoadjuvante/métodos , Neoplasias Retais/diagnóstico por imagem , Neoplasias Retais/tratamento farmacológico , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Reto/diagnóstico por imagem , Resultado do Tratamento
20.
Zhongguo Dang Dai Er Ke Za Zhi ; 22(6): 595-601, 2020 Jun.
Artigo em Zh | MEDLINE | ID: mdl-32571458

RESUMO

OBJECTIVE: To study the clinical features of the diseases associated with aminoacyl-tRNA synthetases (ARS) deficiency. METHODS: A retrospective analysis was performed of the clinical and gene mutation data of 10 children who were diagnosed with ARS gene mutations, based on next-generation sequencing from January 2016 to October 2019. RESULTS: The age of onset ranged from 0 to 9 years among the 10 children. Convulsion was the most common initial symptom (7 children). Clinical manifestations included ataxia and normal or mildly retarded intellectual development (with or without epilepsy; n=4) and onset of epilepsy in childhood with developmental regression later (n=2). Some children experienced disease onset in the neonatal period and had severe epileptic encephalopathy, with myoclonus, generalized tonic-clonic seizure, and convulsive seizure (n=4); 3 had severe delayed development, 2 had feeding difficulty, and 1 had hearing impairment. Mutations were found in five genes: 3 had novel mutations in the AARS2 gene (c.331G>C, c.2682+5G>A, c.2164C>T, and c.761G>A), 2 had known mutations in the DARS2 gene (c.228-16C>A and c.536G>A), 1 had novel mutations in the CARS2 gene (c.1036C>T and c.323T>G), 1 had novel mutations in the RARS2 gene (c.1210A>G and c.622C>T), and 3 had novel mutations in the AARS gene (c.1901T>A, c.229C>T, c.244C>T, c.961G>C, c.2248C>T, and Chr16:70298860-70316687del). CONCLUSIONS: A high heterogeneity is observed in the clinical phenotypes of the diseases associated with the ARS deficiency. A total of 14 novel mutations in 5 genes are reported in this study, which enriches the clinical phenotypes and genotypes of the diseases associated with ARS deficiency.


Assuntos
Aminoacil-tRNA Sintetases/genética , Criança , Epilepsia , Humanos , Mutação , Fenótipo , Estudos Retrospectivos
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