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BACKGROUND/PURPOSE: Existing phototherapies are ineffective for treating patients with vitiligo with complete leukotrichia. We compared the efficacy of reverse perilesional irradiation, during which only the lesional areas are covered, with conventional narrowband ultraviolet B (NB-UVB) home phototherapy for repigmentation of non-segmental vitiligo in patients with complete leukotrichia. METHODS: This was a 12-week, open-label, double-arm, multicenter clinical trial, with a total of 121 patients with non-segmental vitiligo who were randomly divided into two groups (both received topical tacrolimus): the conventional NB-UVB irradiation (CI) and reverse perilesional NB-UVB irradiation (RI) groups. RESULTS: A statistically significant difference in improvement from baseline was observed in the RI group compared with the findings in the CI group (-30.8% ± 11.8% vs. -25.5% ± 11.05%, respectively [p = .010]; pair-wise comparison p = .900 at week 4, p = .104 at week 8, and p = .010 at week 12). At week 12, the average percentage change from baseline of leukotrichia in the irradiation area significantly decreased from 100% to 82.2% ± 13.65% in the RI group, and from 100% to 88.7% ± 9.64% in the CI group (p = .027). Adverse events were minor, including desquamation, dryness, erythema, and blisters. No severe or lasting side effects were observed during the study. CONCLUSION: RI mediated better repigmentation of vitiligo with complete leukotrichia than CI.
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Terapia Ultravioleta , Vitíligo , Humanos , Vitíligo/terapia , Vitíligo/radioterapia , Femenino , Masculino , Adulto , Terapia Ultravioleta/métodos , Pigmentación de la Piel , Persona de Mediana Edad , Adolescente , Tacrolimus/uso terapéutico , Tacrolimus/administración & dosificaciónRESUMEN
BACKGROUND: There are 1.8 million lung cancer deaths worldwide, accounting for 18% of global cancer deaths, including 710,000 in China, accounting for 23.8% of all cancer deaths in China. OBJECTIVE: To explore the out-of-set association rules of lung cancer symptoms and drugs through text mining of traditional Chinese medicine (TCM) treatment of lung cancer, and form medical case analysis to analyze the experience of TCM syndrome differentiation in its treatment. METHODS: The medical records of all patients diagnosed with lung cancer in Nanjing Chest Hospital from January to December 2018 were collected, and the out-of-set association analysis was performed using the MedCase v5.2 TCM clinical scientific research auxiliary platform based on the frequent pattern growth enhanced association analysis algorithm. RESULTS: In terms of TCM treatment of lung cancer, the clinical symptoms with high correlation included cough, expectoration, chest distress, and white phlegm; and the drugs with high correlation included Pinellia ternata, licorice root, white Atractylodes rhizome, and Radix Ophiopogonis; with the prescriptions based on Erchen and Maimendong decoctions. CONCLUSION: This analytical study of the medical cases of TCM treatment for lung cancer was performed using data mining techniques, and the out-of-set association rules between clinical symptoms and drugs were analyzed, including the understanding of lung cancer in TCM. Moreover, the essence of experience in drug use was gathered, providing significant scientific guidance for the clinical treatment of lung cancer.
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Antineoplásicos , Medicamentos Herbarios Chinos , Neoplasias Pulmonares , Humanos , Medicamentos Herbarios Chinos/uso terapéutico , Neoplasias Pulmonares/tratamiento farmacológico , Medicina Tradicional China , Minería de Datos , Antineoplásicos/uso terapéutico , PulmónRESUMEN
OBJECTIVES: To explore the relationship between atherogenic index of plasma (AIP) and childhood asthma. METHODS: This retrospective study included 86 children with asthma admitted to the Changzhou Second People's Hospital Affiliated to Nanjing Medical University from July 2020 to August 2022 as the asthma group and 149 healthy children undergoing physical examination during the same period as the control group. Metabolic parameters including total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and blood glucose, as well as general information of the children such as height, weight, body mass index, presence of specific dermatitis, history of inhalant allergen hypersensitivity, family history of asthma, and feeding history, were collected. Multivariable logistic regression analysis was used to study the relationship between AIP, triglycerides, and high-density lipoprotein cholesterol and asthma. The value of AIP, triglycerides, and high-density lipoprotein cholesterol for predicting asthma was assessed using receiver operating characteristic (ROC) curve analysis. RESULTS: The AIP and triglyceride levels in the asthma group were significantly higher than those in the control group, while high-density lipoprotein cholesterol was significantly lower (P<0.05). However, there was no significant difference in total cholesterol and low-density lipoprotein cholesterol between the two groups (P>0.05). Before and after adjusting for height, weight, presence of specific dermatitis, history of inhalant allergen hypersensitivity, family history of asthma, feeding method, and blood glucose, multivariable logistic regression analysis showed that AIP, triglycerides, and high-density lipoprotein cholesterol were associated with asthma (P<0.05). ROC curve analysis showed that the optimal cutoff value for predicting asthma with AIP was -0.333, with a sensitivity of 80.2%, specificity of 55.0%, positive predictive value of 50.71%, and negative predictive value of 82.85%. The area under the curve (AUC) for AIP in predicting asthma was significantly higher than that for triglycerides (P=0.009), but there was no significant difference in AUC between AIP and high-density lipoprotein cholesterol (P=0.686). CONCLUSIONS: AIP, triglycerides, and high-density lipoprotein cholesterol are all associated with asthma. AIP has a higher value for predicting asthma than triglycerides and comparable value to high-density lipoprotein cholesterol.
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Asma , Dermatitis , Humanos , Niño , Estudios Retrospectivos , Glucemia , Triglicéridos , HDL-Colesterol , LDL-Colesterol , Asma/etiología , Factores de RiesgoRESUMEN
PURPOSE: The aim of this study is to develop and optimize an adiabatic T 1 ρ $$ {\mathrm{T}}_{1\uprho} $$ ( T 1 ρ , adiab $$ {\mathrm{T}}_{1\uprho, \mathrm{adiab}} $$ ) mapping method for robust quantification of spin-lock (SL) relaxation in the myocardium at 3T. METHODS: Adiabatic SL (aSL) preparations were optimized for resilience against B 0 $$ {\mathrm{B}}_0 $$ and B 1 + $$ {\mathrm{B}}_1^{+} $$ inhomogeneities using Bloch simulations. Optimized B 0 $$ {\mathrm{B}}_0 $$ -aSL, Bal-aSL and B 1 $$ {\mathrm{B}}_1 $$ -aSL modules, each compensating for different inhomogeneities, were first validated in phantom and human calf. Myocardial T 1 ρ $$ {\mathrm{T}}_{1\uprho} $$ mapping was performed using a single breath-hold cardiac-triggered bSSFP-based sequence. Then, optimized T 1 ρ , adiab $$ {\mathrm{T}}_{1\uprho, \mathrm{adiab}} $$ preparations were compared to each other and to conventional SL-prepared T 1 ρ $$ {\mathrm{T}}_{1\uprho} $$ maps (RefSL) in phantoms to assess repeatability, and in 13 healthy subjects to investigate image quality, precision, reproducibility and intersubject variability. Finally, aSL and RefSL sequences were tested on six patients with known or suspected cardiovascular disease and compared with LGE, T 1 $$ {\mathrm{T}}_1 $$ , and ECV mapping. RESULTS: The highest T 1 ρ , adiab $$ {\mathrm{T}}_{1\uprho, \mathrm{adiab}} $$ preparation efficiency was obtained in simulations for modules comprising 2 HS pulses of 30 ms each. In vivo T 1 ρ , adiab $$ {\mathrm{T}}_{1\uprho, \mathrm{adiab}} $$ maps yielded significantly higher quality than RefSL maps. Average myocardial T 1 ρ , adiab $$ {\mathrm{T}}_{1\uprho, \mathrm{adiab}} $$ values were 183.28 ± $$ \pm $$ 25.53 ms, compared with 38.21 ± $$ \pm $$ 14.37 ms RefSL-prepared T 1 ρ $$ {\mathrm{T}}_{1\uprho} $$ . T 1 ρ , adiab $$ {\mathrm{T}}_{1\uprho, \mathrm{adiab}} $$ maps showed a significant improvement in precision (avg. 14.47 ± $$ \pm $$ 3.71% aSL, 37.61 ± $$ \pm $$ 19.42% RefSL, p < 0.01) and reproducibility (avg. 4.64 ± $$ \pm $$ 2.18% aSL, 47.39 ± $$ \pm $$ 12.06% RefSL, p < 0.0001), with decreased inter-subject variability (avg. 8.76 ± $$ \pm $$ 3.65% aSL, 51.90 ± $$ \pm $$ 15.27% RefSL, p < 0.0001). Among aSL preparations, B 0 $$ {\mathrm{B}}_0 $$ -aSL achieved the better inter-subject variability. In patients, B 1 $$ {\mathrm{B}}_1 $$ -aSL preparations showed the best artifact resilience among the adiabatic preparations. T 1 ρ , adiab $$ {\mathrm{T}}_{1\uprho, \mathrm{adiab}} $$ times show focal alteration colocalized with areas of hyper-enhancement in the LGE images. CONCLUSION: Adiabatic preparations enable robust in vivo quantification of myocardial SL relaxation times at 3T.
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Corazón , Imagen por Resonancia Magnética , Humanos , Imagen por Resonancia Magnética/métodos , Reproducibilidad de los Resultados , Corazón/diagnóstico por imagen , Miocardio , Contencion de la Respiración , Fantasmas de ImagenRESUMEN
BACKGROUND: In recent years, malignant tumors have gradually become one of the main causes of death for Chinese residents, of which lung cancer ranks first in both the incidence and mortality in China. OBJECTIVE: To mine the text of traditional Chinese medicine (TCM) clinical medical cases after data cleaning, analyze it, and study the experience of TCM doctors in treating non-small cell lung cancer (NSCLC). METHODS: The applied approach was based on the data mining methods of decentralized and hierarchical system clustering of data from a drug and prescription database. This study involved 215 patients, 287 cases, and 147 types of clinical drugs. RESULTS: The data analysis of the clinical treatment of NSCLC in TCM showed that Erchen Decoction was the main method for the treatment of non-small cell lung cancer in clinical treatment of non-small cell lung cancer. Junjian recipes were close to each other, with Banzhilian, Lobelia, Shanci Mushroom, Hedyotis diffusa to anticancer and detoxify. CONCLUSION: This study analyzed the core TCM prescription for NSCLC by collecting the empirical essence and characteristics of specific medications. It has some guiding scientific significance for the clinical treatment of lung cancer.
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Carcinoma de Pulmón de Células no Pequeñas , Medicamentos Herbarios Chinos , Neoplasias Pulmonares , Humanos , Medicina Tradicional China/métodos , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Medicamentos Herbarios Chinos/uso terapéutico , PrescripcionesRESUMEN
Crystal monochromators are indispensable optical components for the majority of beamlines at synchrotron radiation facilities. Channel-cut monochromators are sometimes chosen to filter monochromatic X-ray beams by virtue of their ultrahigh angular stability. Nevertheless, high-accuracy polishing on the inner diffracting surfaces remains challenging, thus hampering their performance in preserving the coherence or wavefront of the photon beam. Herein, a magnetically controlled chemical-mechanical polishing (MC-CMP) approach has been successfully developed for fine polishing of the inner surfaces of channel-cut crystals. This MC-CMP process relieves the constraints of narrow working space dictated by small offset requirements and achieves near-perfect polishing on the surface of the crystals. Using this method, a high-quality surface with roughness of 0.614â nm (root mean square, r.m.s.) is obtained in a channel-cut crystal with 7â mm gap designed for beamlines at the High Energy Photon Source, a fourth-generation synchrotron radiation source under construction. On-line X-ray topography and rocking-curve measurements indicate that the stress residual layer on the crystal surface was removed. Firstly, the measured rocking-curve width is in good agreement with the theoretical value. Secondly, the peak reflectivity is very close to theoretical values. Thirdly, topographic images of the optics after polishing were uniform without any speckle or scratches. Only a nearly 2.5â nm-thick SiO2 layer was observed on the perfect crystalline matrix from high-resolution transmission electron microscopy photographs, indicating that the structure of the bulk material is defect- and dislocation-free. Future development of MC-CMP is promising for fabricating wavefront-preserving and ultra-stable channel-cut monochromators, which are crucial to exploit the merits of fourth-generation synchrotron radiation sources or hard X-ray free-electron lasers.
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Absolute measurement of radiant power in the X-ray region is essential for many applications in astrophysics, spectroscopy, and X-ray diagnostics. Comparison between different measuring methods is an effective way to check their reliability. In the present work, a comparison of X-ray radiant power absolute measurement between a free-air ionization chamber and a cryogenic electrical substitution radiometer was performed at Beijing Synchrotron Radiation Facility. The absolute radiant power obtained by these two methods were mutually compared via a transfer standard detector's spectral responsivity at a photon energy of 10 keV. The result of the comparison showed that the difference was 0.47%. A conclusion was reached that the free-air ionization chamber and the cryogenic electrical substitution radiometer agreed within the combined relative uncertainty of 3.35%.
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Ionización del Aire , Radiometría , Rayos X , Reproducibilidad de los Resultados , Radiometría/métodos , RadiografíaRESUMEN
BACKGROUND: Radiofrequency catheter ablation (RFCA) of premature ventricular contractions (PVCs) originating from common locations such as the proximal and middle fascicles of the His-Purkinje system (HPS) has been established as an effective therapy. This report aims to highlight the electrophysiological properties and RFCA of PVCs originating from uncommon locations of the HPS. METHODS: Among 57 patients with fascicular PVCs, 3 with fascicular PVCs originating from uncommon sites were retrospectively analyzed. RESULTS: We identified three patients with PVCs originating separately from diseased fascicles, the dead-end tract (DET), and the distal fascicle. In contrast to PVCs originating from the proximal and medial fascicles, the fascicular potentials could not be recorded at the target sites of patients with PVCs originating from diseased fascicles or the distal fascicle during sinus rhythm. However, these PVCs were successfully ablated from the HPS, guided by recording their earliest fascicular potentials in PVCs. PVCs originating from the DET are morphologically consistent with those originating from the proximal left anterior fascicle or the distal left bundle branch. The corresponding tiny sharp potential of the DET could be mapped, and RFCA of the right coronary cusp achieved successful suppression of PVCs. CONCLUSIONS: The knowledge of the different electrophysiological characteristics of fascicular PVCs originating from uncommon locations can contribute to precise mapping and ablation. For such arrhythmia, the target site for successful ablation should be identified by earliest fascicular potential.
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Ablación por Catéter , Taquicardia Ventricular , Complejos Prematuros Ventriculares , Humanos , Complejos Prematuros Ventriculares/diagnóstico por imagen , Complejos Prematuros Ventriculares/cirugía , Estudios Retrospectivos , Resultado del Tratamiento , Sistema de Conducción Cardíaco , Electrocardiografía , Taquicardia Ventricular/cirugíaRESUMEN
As one of the typical carbon nanomaterials, graphdiyne (GDY) with unique chemical, physical, and electronic properties has a great potential in various fields. Although it is an important member of carbon nanozymes, the research on its intrinsic enzyme mimetic properties and applications is still limited. Herein, graphdiyne oxide quantum dots (GDYO QDs) have been synthesized through oxidative cleavage, which exhibit enhanced peroxidase-like activity with lower Km and higher Vmax than those of most carbon-based nanozymes. The catalytic mechanism is explored, showing that the enhanced catalytic performance is attributed to the good conjugated structure, large number of oxygen-containing groups, and small-sized nanosheets with few layers. As a kind of peroxidase mimetic, the GDY-based nanozyme has excellent potential in sensing H2O2 and biological antioxidants through the colorimetric assay, with a linear range from 5 to 500 µM and detection limit of 1.5 µM for H2O2 and a linear range from 0 to 90 µM and detection limit of 0.48 µM for l-cysteine. Our work will be beneficial to develop high-performance artificial enzymes and to understand their mechanism for better applications.
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Puntos Cuánticos , Antioxidantes , Carbono/química , Cisteína , Grafito , Peróxido de Hidrógeno , Óxidos , Peroxidasa , Peroxidasas , Puntos Cuánticos/químicaRESUMEN
Background: Sintilimab is a fully human monoclonal antibody targeting PD-1, which has been considered well tolerated among patients and widely applied in malignancies. Case Presentation: We present a case report of a patient with gallbladder carcinoma treated with sintilimab who developed toxic epidermal necrolysis (TEN). A 72-year-old female presented with fever and maculopapular rash after receiving one dose of sintilimab for metastatic gallbladder carcinoma. Widespread maculopapular rashes with progressive skin detachment occurred within one week. Early skin biopsy of the patient showed apoptotic keratinocytes along with interface dermatitis. She was initially treated with escalating methylprednisolone (from 0.8 to 1.6 mg/kg/d) and subsequently in the combination of intravenous immunoglobulin. Her skin lesions significantly improved, and satisfying re-epithelialization was achieved after 43 days of hospitalization. Conclusion: Because of the high mortality of grade four immune related adverse event (irAE) on skin, we recommend early monitoring and recognition of symptoms. During management, high-dose glucocorticoids with combined intravenous immune globulin and supportive care may be helpful.
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Background: The origin distribution in right ventricular outflow tract (RVOT) ventricular arrhythmias (VAs), as well as the initial ablation effectiveness of reversed U-curve method and antegrade method, remains unclear. Objectives: To investigate the origin distribution of RVOT-type VAs and compare the initial ablation effectiveness of the two methods. Method: Consecutive patients who had idiopathic RVOT-type VAs were prospectively enrolled. After activation mapping, patients were randomly assigned to supravalvular strategy using the reversed U-curve or subvalvular strategy using the antegrade method. The primary outcome was initial ablation (IA) success, defined as the successful ablation within the first three attempts. Results: Sixty-one patients were enrolled from November 2018 to June 2020. Activation mapping revealed that 34/61 (55.7%) of the earliest ventricular activating (EVA) sites were above the pulmonary valves (PVs). The IA success rate was 25/33 (75.8%) in the patients assigned to supravalvular strategy as compared with 16/28 (57.1%) in those assigned to subvalvular strategy (p = 0.172). Multivariate analysis revealed a substantial and qualitative interaction between the EVA sites and IA strategies (p interaction < 0.001). Either strategy had a remarkably higher IA success rate in treating its ipsilateral EVA sites than contralateral ones (p < 0.0083). Conclusion: Of the idiopathic RVOT-type VA origins, half were located above the PV. The supravalvular and subvalvular strategies did not differ in IA success rates. However, they were complementary to reveal the EVA sites and facilitate ipsilateral ablation, which produces a significantly higher IA success rate. Clinical Trial Registration: Chinese Clinical Trial Registry number, https://www.chictr.org.cn/showproj.aspx?proj=45623, ChiCTR2000029331.
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It has been shown that the activation of calcineurin is involved in regulating ion channel remodeling in hypertrophic cardiomyocytes. But the precise role of calcineurin in the regulation of transient outward potassium current (I to), an ion channel associated with fatal arrhythmia, remains controversial. This study aimed to examine the effects of calcineurin Aß (CnAß) gene knockdown on I to channel remodeling and action potential duration (APD) in the hypertrophic ventricular myocytes of neonatal rats. Results showed that phenylephrine stimulation caused hypertrophy of ventricular myocytes, upregulation of CnAß protein expression, downregulation of Kv4.2 mRNA and protein expression, a decrease in I to current density, and prolongation of APD. CnAß gene knockdown significantly inhibited the effects of phenylephrine stimulation. Our data indicate that CnAß gene knockdown can inhibit I to channel remodeling and APD prolongation in hypertrophic neonatal rat ventricular myocytes. This finding suggests that calcineurin may be a potential target for the prevention of malignant ventricular arrhythmia in a hypertrophic heart.
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The design and development of high-performance photocatalysts from three aspects of simultaneous enhancement of light harvest, carrier migration rate, and redox reaction rate is still a great challenge. Herein, a novel Co9S8/CdIn2S4 ohmic junction with a robust internal electric field (IEF) is successfully prepared via hydrothermal and in situ synthesis methods and is used for effective photocatalytic H2 evolution (PHE). Under simulated visible light irradiation, the PHE rate of 5% Co9S8/CdIn2S4 can reach 1083.6 µmol h-1 g-1, which is 6.4 times higher than that of CdIn2S4 (170.5 µmol h-1 g-1). The enhanced PHE performance is mainly ascribed to the improved light harvest and carrier separation efficiency and fast surface H2 evolution kinetics. Moreover, Co9S8 nanotubes serve as promising Co-based cocatalysts that can evidently enhance PHE activity. Additionally, Co9S8/CdIn2S4 shows superior stability because the photogenerated carrier transfer path restrains the photocorrosion behavior. The photocatalytic mechanism is proposed based on experimental results and DFT calculations. This work offers new insights for the design and development of highly active photocatalysts from interface engineering.
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BACKGROUND: The complexity of left atrial appendage (LAA) in patients with nonvalvular atrial fibrillation (NVAF) is closely related to LAA thrombosis and stroke incidence. But the classification of LAA morphology is not uniform and controversial. HYPOTHESIS: This study divided the LAA into two categories according to the LAA morphology to investigate the risk of thrombosis related to the LAA structural complexity in NVAF patients. METHODS: A total of 336 NVAF patients were enrolled continuously in this study. The patients were divided into thrombosis group and non-thrombosis group according to whether the thrombus presence in LAA. Through computer LAA three-dimensional reconstruction, LAA morphology was divided into the complex type and simple type according to with or without the clearly lobulated structure judged by imaging experts. The relationship between LAA thrombosis and various potential risk factors was analyzed. RESULTS: A total of 19 potential risk factors for LAA thrombosis in NVAF patients were enrolled into statistical analysis. The coincidence rate of LAA morphology classification was 96.4% (324/336) between two imaging experts. Multivariate logistic regression analysis showed that complex LAA morphology (OR 4.168, 95% CI 1.871-9.288, P < .001) was associated with the presence of LAA thrombus, independently of other enrolled risks. CONCLUSIONS: It is a concise and reliable method to divide the LAA morphology into complex type and simple type according to whether with the clearly lobulated structure. The complex LAA is an independent risk factor for LAA thrombosis in NVAF patients.
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Apéndice Atrial/fisiopatología , Fibrilación Atrial/complicaciones , Fibrilación Atrial/diagnóstico por imagen , Trombosis/diagnóstico por imagen , Trombosis/etiología , Anciano , Apéndice Atrial/diagnóstico por imagen , Ecocardiografía Transesofágica/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de RiesgoRESUMEN
BACKGROUND: We previously confirmed the targeting of high-mobility group box 1 (HMGB1) by miR-25. This project aims to further investigate whether miR-25 improves myocardial ischemia-reperfusion injury (IRI) in vivo by targeting HMGB1. METHODS: A rat model of myocardial IRI was established by the ligation of the left anterior descending coronary artery for 45 minutes followed by 2, 4, or 6 hours reperfusion. The expression of miR-25, HMGB1, and apoptosis-related proteins in the myocardium was determined by quantitative real-time polymerase chain reaction (PCR) and western blotting. The activities of myocardial enzymes and the release of inflammatory cytokines were evaluated by enzyme-linked immunosorbent assay. Evans blue/triphenyltetrazolium chloride double staining was performed to assess infarct size. Myocardial apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling staining. RESULTS: MiR-25 expression was significantly downregulated, while HMGB1 was highly expressed at the mRNA and protein levels in myocardial tissues after induction of the IRI model. MiR-25 agomir administration suppressed the expression of HMGB1 in myocardial tissues. Furthermore, administration of both miR-25 agomir and lentivirus-mediated short hairpin RNA (shRNA) interference targeting HMGB1 sh-HMGB1 resulted in reduced serum myocardial enzyme activities, cytokine secretion, and myocardial apoptosis during myocardial IRI. CONCLUSION: MiR-25 mitigated myocardial IRI-induced damage by targeting HMGB1.
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Proteína HMGB1/genética , MicroARNs/fisiología , Daño por Reperfusión Miocárdica/prevención & control , Animales , Apoptosis , Citocinas/biosíntesis , Modelos Animales de Enfermedad , Masculino , Miocardio/patología , Ratas Sprague-DawleyRESUMEN
The total calcium (tCa) in blood serum comprises free Ca2+ ions (fCa), protein-bound calcium (prCa), and complexed calcium by small anions (cCa). The cCa fraction, in addition to fCa, has been indicated to have some physiological activity. However, there is little evidence for the structure of its constituents. Here we report an ex vivo detection of the cCa constituents by synchrotron X-ray absorption near-edge structure spectroscopy. We collected the data directly on rat blood serum and, by making use of the reference samples, derived a spectrum that exhibits the features of cCa constituents. Among the features are those of the complexes of calcium phosphate and calcium carbonate. The detected complexes in the cCa fraction are mainly Ca(η2-HPO4)(H2O)4 and Ca(η1-HCO3)(H2O)5+, in which HPO42- and HCO3- serve as bidentate and unidentate ligands, respectively. The remained H2O molecules on the coordination sphere of Ca2+ enable these complexes to behave partially like aquated Ca2+ ions in protein-binding. Besides, as the dominant part of prCa, albumin-bound calcium (albCa) exhibits a spectrum that closely resembles that of fCa, indicating weak interactions between the protein carboxyl groups and calcium. The weak-bound cCa and albCa, along with fCa and the relevant anions, compose a local chemical system that could play a role in maintaining the calcium level in blood.
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Carbonato de Calcio/sangre , Fosfatos de Calcio/sangre , Animales , Calcio/metabolismo , Ligandos , Ratas , Agua/química , Espectroscopía de Absorción de Rayos XRESUMEN
An understanding of the species of chlorine is crucial in the metropolis-Beijing, which is suffering serious haze pollution with high frequency. Particulate Matters (PMs) with five different sizes were collected in Beijing from July 2009 to March 2016, and characterized non-destructively by X-ray absorption near edge structure spectroscopy. PM<0.2, PM0.2-0.5 and PM>2.5 contributed for the major PMs mass in spring and summer, PM0.5-1.0 and PM1.0-2.5 contributed for the major PMs mass in autumn and winter. The concentrations of the three chlorine species were in the order of inorganic chlorine (Clinorg)â¯>â¯aliphatic chlorine (Clali)â¯>â¯aromatic chlorine (Claro), indicating that Clinorg constituted the primary chlorine fraction and less toxic Clali constituted the primary total organic chlorine (Clali + Claro, abbreviated as Clorg) in the PMs in Beijing. In addition, these three chlorine species exhibited identical seasonal variation in PM2.5: winterâ¯>â¯autumnâ¯>â¯springâ¯>â¯summer. Wet precipitation is an important factor to result in the lower mass concentrations of these three chlorine species in summer. The temporal variations of both size resolved PM mass concentrations and chlorine species concentrations suggested that the air pollution prevention and control in Beijing has just won initial success.
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Contaminantes Atmosféricos/análisis , Cloro/análisis , Beijing , China , Cloro/química , Monitoreo del Ambiente/métodos , Tamaño de la Partícula , Material Particulado/análisis , Estaciones del Año , Espectroscopía de Absorción de Rayos X/métodosRESUMEN
Advances in the fundamentals and applications of diffraction gratings have received much attention. However, conventional diffraction gratings often suffer from higher-order diffraction contamination. Here, we introduce a simple and compact single optical element, named inclined rectangular aperture gratings (IRAG), for quasi suppression of higher-order diffractions. We show, both in the visible light and soft x-ray regions, that IRAG can significantly suppress higher-order diffractions with moderate diffraction efficiency. Especially, as no support strut is needed to maintain the free-standing patterns, the IRAG is highly advantageous to the extreme-ultraviolet and soft x-ray regions. The diffraction efficiency of the IRAG and the influences of fabrication constraints are also discussed. The unique quasi-single order diffraction properties of IRAG may open the door to a wide range of photonic applications.
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Outstanding magnetic properties are highly desired for two-dimensional ultrathin semiconductor nanosheets. Here, we propose a phase incorporation strategy to induce robust room-temperature ferromagnetism in a nonmagnetic MoS2 semiconductor. A two-step hydrothermal method was used to intentionally introduce sulfur vacancies in a 2H-MoS2 ultrathin nanosheet host, which prompts the transformation of the surrounding 2H-MoS2 local lattice into a trigonal (1T-MoS2) phase. 25% 1T-MoS2 phase incorporation in 2H-MoS2 nanosheets can enhance the electron carrier concentration by an order, introduce a Mo(4+) 4d energy state within the bandgap, and create a robust intrinsic ferromagnetic response of 0.25 µB/Mo by the exchange interactions between sulfur vacancy and the Mo(4+) 4d bandgap state at room temperature. This design opens up new possibility for effective manipulation of exchange interactions in two-dimensional nanostructures.
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Nitrogen (N) is a common limiting nutrient in crop production. The N content of soil has been used as an important soil fertility index. Organic N is the major form of N in soil. In most agricultural surface soils, more than 90% of total N occurs in organic forms. Therefore, understanding the compositional characteristics of soil organic N functional groups can provide the scientific basis for formulating the reasonable farmland management strategies. Synchrotron radiation soft X-ray absorption near-edge structure (N K-edge XANES) spectroscopy is the most powerful tool to characterize in situ organic N functional groups compositions in soil. However, to our most knowledge, no studies have been conducted to examine the organic N functional groups compositions of soil using N K-edge XANES spectroscopy under long-term fertilization practices. Based on a long-term field experiment (started in 1990) in a black soil (Gongzhuling, Northeast China), we investigated the differences in organic N functional groups compositions in bulk soil and clay-size soil fraction among fertilization patterns using synchrotron-based N K- edge XANES spectroscopy. Composite soil samples (0-20 cm) were collected in 2008. The present study included six treatments: farmland fallow (FALL), no-fertilization control (CK), chemical nitrogen, phosphorus, and potassium fertilization (NPK), NPK in combination with organic manure (NPKM), 1.5 times of NPKM (1.5 NPKM), and NPK in combination with maize straw (NPKS). The results showed that N K-edge XANES spectra of all the treatments under study exhibited characteristic absorption peaks in the ranges of 401.2-401.6 and 402.7-403.1 eV, which were assigned as amides/amine-N and pyrrole-N, respectively. These characteristic absorption peaks were more obvious in clay-size soil fraction than in bulk soil. The results obtained from the semi-quantitative analysis of N K-edge XANES spectra indicated that the relative proportion of amides/amine-N was the highest in both bulk soil and clay-size soil fraction, and it was the most major forms in soil organic nitrogen functional groups. Compared with the FALL treatment, the relative proportion of amide/amine-N was lower whereas that of Pyrrole-N was higher in the CK treatment. In the treatments with combined chemical fertilizers and organic manure, the relative proportion of amide/amine-N decreased with increasing application rates of organic manure, while that of Pyrrole-N had an opposite trend. In bulk soil, the relative proportion of amide/amine-N was the highest for the NPKS treatment than for the other treatments. On the other hand, the relative proportion of nitrile/aromatic-N was the highest for the Fallow treatment than for the other treatments in clay-size soil fraction. It is feasible to use N K-edge XANES spectroscopy for characterizing in situ the changes of organic N functional groups in soil under different fertilization practices.