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Objective: To measure the overall and lobulated volume of the liver with different degrees of liver fibrosis and to further observe pathological changes such as liver microvasculature, hepatocyte apoptosis, and regeneration in order to understand the macroscopic volume changes of the liver during liver fibrosis and its relationship with liver tissue microscopic pathology in patients with chronic liver disease. Methods: 53 patients with chronic hepatitis B, alcoholic fatty liver disease, autoimmune liver disease, nonalcoholic fatty liver disease, and drug-induced chronic liver disease who underwent both liver biopsy tissue and abdominal magnetic resonance imaging were collected. Patients were divided into early (F1-2), middle (F3-4), and late (F5-6) in accordance with the Ishak fibrosis stage and Masson stain. The liver and spleen volumes were measured using ITK-SNAP software. CD31 immunohistochemical staining was used to reflect intrahepatic angiogenesis. Ki67 and HNF-4α multiplex immunohistochemical staining were used to reflect hepatocyte regeneration. GS staining was used to determine parenchymal extinction lesions. TUNEL staining was used to observe hepatocyte apoptosis. Spearman correlation analysis was used to analyze the relationship between liver volume changes and liver histopathological changes. Results: As liver fibrosis progressed, the total liver volume and right lobe liver volume gradually decreased (P<0.05), while the spleen volume gradually increased (P<0.05). The expression of CD31 and GS gradually increased (P<0.05), and the expression of Ki67 first increased and then decreased (P<0.05). The positivity rate of CD31 was negatively correlated with the right lobe liver volume (r=-0.609, P<0.001) and the total liver volume (r=-0.363, P=0.017). The positivity rate of Ki67 was positively correlated with the right lobe liver volume (r=0.423, P=0.018), while the positivity rate of apoptotic cells was significantly negatively correlated with the total liver volume (r=-0.860, P<0.001). The positivity rate of GS was negatively correlated with the right lobe liver volume (r=-0.440, P=0.002), and the number of PELs was negatively correlated with RV (r=-0.476, P=0.013). The CD31 positive staining area was negatively correlated with the Ki67 positive staining area(r=-0.511, P=0.009). Conclusion: As liver fibrosis progresses, patients with chronic liver disease have a depletion in total liver volume and right lobe liver volume, and this is mainly in correlation with fewer liver cells and liver tissue microvasculature disorders.
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Cirrosis Hepática , Hígado , Humanos , Cirrosis Hepática/patología , Hígado/patología , Masculino , Femenino , Persona de Mediana Edad , Adulto , Anciano , Regeneración Hepática , Enfermedad Crónica , Hepatocitos/patología , Hepatocitos/metabolismo , Tamaño de los Órganos , Apoptosis , Hepatitis B Crónica/complicaciones , Hepatitis B Crónica/patologíaRESUMEN
Objective: To compare the short-term efficacy and the safety of microwave ablation (MWA) and radiofrequency ablation (RFA) in the treatment of benign thyroid nodules (BTNs). Methods: This prospective randomized controlled trial, performed from December 2019 to September 2021, included 36 patients with solid or predominantly solid BTNs who met the eligibility criteria and provided written informed consent at the Nanjing sub-center (Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine). Patients were assigned to either the MWA group or the RFA group (18 patients in each group) at a ratio of 1â¶1 using a block randomization design and allocation concealment using sealed envelope randomization. The independent-sample t-test and χ2 test were used to compare the volume reduction rates (VRRs), effective rates (VRRs≥50%), cosmetic scores, and complication rates at 1, 3, and 6 months after treatment between the two groups. Results: The clinical characteristics of the two groups of patients were comparable. After ablation, the nodule volume was significantly reduced in both groups. At 1, 3, and 6 months, there was no significant difference in the volume between the two groups (all P>0.05). At 3 months, the RFA group had a larger VRRs than that in the MWA group (62.08%±12.46% vs. 46.90%±23.16%, t=-2.45, P=0.021). However, at 1 and 6 months, no statistical significance was observed (both P>0.05). No significant difference was observed in the effective rates at the last follow-up (14/18 vs. 18/18, P=0.104). However, the RFA group had a lower cosmetic score than that in the MWA group (1.78±0.43 vs. 2.17±0.51, t=-2.47, P=0.019). There was no statistically significant difference in the complication rates between the two groups (all P>0.05). Conclusions: Both MWA and RFA were effective and safe treatments for BTNs, with no significant differences in short-term efficacy and safety. In addition, the RFA group showed slightly more favorable outcomes than the MWA group in terms of cosmetic improvement.
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Ablación por Radiofrecuencia , Nódulo Tiroideo , Humanos , Microondas , Estudios Prospectivos , Nódulo Tiroideo/cirugía , HospitalesRESUMEN
Increasing the carrier density in a Mott insulator by chemical doping gives rise to a generic superconducting dome in high temperature superconductors. An intriguing question is whether a second superconducting dome may exist at higher dopings. Here we heavily overdope La2-xSrxCuO4 (0.45 ≤ x ≤ 1.0) and discover an unprecedented reentrance of interface superconductivity in La2-xSrxCuO4 /La2CuO4 heterostructures. As x increases, the superconductivity is weakened and completely fades away at x = 0.8; but it revives at higher doping and fully recovers at x = 1.0. This is shown to be correlated with the suppression of the interfacial charge transfer around x = 0.8 and the weak-to-strong localization crossover in the La2-xSrxCuO4 layer. We further construct a theoretical model to account for the sophisticated relation between charge localization and interfacial charge transfer. Our work advances both the search for and control of new superconducting heterostructures.
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Objective: To investigate the blood pressure change in patients with acute ischemic stroke (AIS) and hypertension treated with cinepazide maleate injection. Methods: This was a subgroup analysis of post-marketing clinical confirmation study of cinepazide maleate injection for acute ischemic stroke: a randomized, double-blinded, multicenter, placebo-parallel controlled trial, which conducted in China from August 2016 to February 2019. Eligible patients fulfilled the inclusive criteria of acute anterior circulation ischemic stroke with National Institutes of Health Stroke Scale (NIHSS) scores of 7-25. The primary endpoints were mean blood pressure of AIS patients treated with cinepazide maleate or control, which were assessed during the treatment period (14 days), and the proportion of the patients with normal blood pressure was analyzed after the treatment period. Furthermore, a subgroup analysis was performed to investigate a possible effect of the history of hypertension on outcomes. Results: This analysis included 809 patients with hypertension. There was no significant difference in patients blood pressure and the proportion of patients with normal blood pressure (60.5% vs. 59.0%,P>0.05) between cinepazide maleate group and control group. Conclusion: Administration of cinepazide maleate injection does not affect the management of clinical blood pressure in patients with AIS.
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Isquemia Encefálica , Hipertensión , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Presión Sanguínea , Isquemia Encefálica/tratamiento farmacológico , Humanos , Hipertensión/tratamiento farmacológico , Piperazinas , Accidente Cerebrovascular/tratamiento farmacológico , Resultado del TratamientoRESUMEN
The Mn-based superconductor is rare owing to the strong magnetic pair-breaking effect. Here we report on the discovery of pressure-induced superconductivity in KMn_{6}Bi_{5}, which becomes the first ternary Mn-based superconductor. At ambient pressure, the quasi-one-dimensional KMn_{6}Bi_{5} is an antiferromagnetic metal with T_{N}≈75 K. By measuring resistance and ac magnetic susceptibility under hydrostatic pressures up to 14.2 GPa in a cubic anvil cell apparatus, we find that its antiferromagnetic transition can be suppressed completely at a critical pressure of P_{c}≈13 GPa, around which bulk superconductivity emerges and displays a superconducting dome with the maximal T_{c}^{onset}=9.3 K achieved at about 14 GPa. The close proximity of superconductivity to a magnetic instability in the temperature-pressure phase diagram of KMn_{6}Bi_{5} and an unusually large µ_{0}H_{c2}(0) exceeding the Pauli paramagnetic limit suggests an unconventional magnetism-mediated paring mechanism. In contrast to the binary MnP, the flexibility of the crystal structure and chemical compositions in the ternary AMn_{6}Bi_{5} (A=alkali metal) can open a new avenue for finding more Mn-based superconductors.
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Using femtosecond time-resolved x-ray diffraction, we investigated optically excited coherent acoustic phonons in the Weyl semimetal TaAs. The low symmetry of the (112) surface probed in our experiment enables the simultaneous excitation of longitudinal and shear acoustic modes, whose dispersion closely matches our simulations. We observed an asymmetry in the spectral line shape of the longitudinal mode that is notably absent from the shear mode, suggesting a time-dependent frequency chirp that is likely driven by photoinduced carrier diffusion. We argue on the basis of symmetry that these acoustic deformations can transiently alter the electronic structure near the Weyl points and support this with model calculations. Our study underscores the benefit of using off-axis crystal orientations when optically exciting acoustic deformations in topological semimetals, allowing one to transiently change their crystal and electronic structures.
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Dispersion impairments are a well-known limitation in data center communications, limiting both the usable data rates and reaches. Several companies today adopt silicon photonics as a core technology in their transceiver products. This presents an opportunity for silicon photonics-based dispersion management technologies to be integrated with the transceiver transmitter or receiver. In this manuscript, we present a ring-resonator based, tunable dispersion compensation device, providing dispersion ranging as wide from + 12.9 × 103ps/nm to -12.3 × 103ps/nm. Thermo-optic tuning from 20°C to 70°C is demonstrated to allow continuous wavelength tuning across 200â GHz. High-speed experiments using 25 Gb/s non-return-to-zero data propagating through 20â km of single mode fiber show that a significant improvement in the eye diagram is achieved after compensation with the ring-resonator device. We demonstrate a significant improvement in the BER from 10-3 to 10-11 for data rates of 25 and 25.78125 Gb/s.
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Symmetry plays a central role in conventional and topological phases of matter, making the ability to optically drive symmetry changes a critical step in developing future technologies that rely on such control. Topological materials, like topological semimetals, are particularly sensitive to a breaking or restoring of time-reversal and crystalline symmetries, which affect both bulk and surface electronic states. While previous studies have focused on controlling symmetry via coupling to the crystal lattice, we demonstrate here an all-electronic mechanism based on photocurrent generation. Using second harmonic generation spectroscopy as a sensitive probe of symmetry changes, we observe an ultrafast breaking of time-reversal and spatial symmetries following femtosecond optical excitation in the prototypical type-I Weyl semimetal TaAs. Our results show that optically driven photocurrents can be tailored to explicitly break electronic symmetry in a generic fashion, opening up the possibility of driving phase transitions between symmetry-protected states on ultrafast timescales.
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Objective: To investigate whether the overexpression of Numb gene can effectively intervene the progression of cholestatic liver fibrosis (CLF) in adult liver. Methods: Twenty-four SD rats were randomly divided into sham operation (Sham, n=6), common bile duct ligation (BDL, n=6), empty vector plasmid (Numb-EV, n=6) and numb gene overexpression group (Numb-OE, n=6). The CLF model was prepared by common bile duct ligation. Simultaneously, the model was established, and the adeno-associated virus (AAV) carrying the cloned numb gene was injected into the rats' spleens. Samples were collected at the end of four weeks. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin (Alb), serum total bilirubin (TBil), serum total bile acid (TBA), liver histopathology, liver tissue hydroxyproline (Hyp) content, and alpha smooth muscle actin (α-SMA), cytokeratin (CK) 7, and CK19 expression conditions were determined in liver tissue. An analysis of variance was used to compare the means of multiple groups. Results: Compared with the Sham group, the Numb mRNA level in the rat liver tissue was significantly decreased in the BDL group (0.872±0.237 vs. 0.452±0.147, P=0.003). Compared with the Numb-EV group, the Numb mRNA level in the liver tissue was significantly increased in the Numb-OE group (0.487±0.122 vs. 1.094±0.345, Pï¼0.01). Compared with the Sham group, the Hyp content (µg/L) (288.46±49.49 vs. 901.98±271.85, Pï¼0.01) and the α-SMA mRNA level (0.858±0.234 vs. 8.976±1.398, Pï¼0.01) were significantly higher in the BDL group. Compared with the Numb-EV group, the Hyp content (864.32±113.54 vs. 580.44±171.77, P=0.039), the α-SMA mRNA level (6.138±1.443 vs. 1.322±0.859, Pï¼0.01) and the protein levels were significantly reduced in the Numb-OE group. Compared with the Sham group, the serum ALT, AST, TBil, and TBA levels were significantly increased in the BDL group (Pï¼0.01), and the ALB content was significantly decreased (Pï¼0.01). Compared with the Numb-EV group, AST and TBil levels were significantly reduced in the Numb-OE group (Pï¼0.01), as were the ALT and TBA levels (Pï¼0.05); however, the ALB content was significantly increased (Pï¼0.01), and the differences were statistically significant. Compared with the Sham group, the mRNA expression levels of CK7 and CK19 were significantly increased in the BDL group (1.40±0.42 vs. 43.78±7.56; 1.11±0.51 vs. 363.81±134.84, Pï¼0.01). The mRNA expression levels of CK7 and CK19 were significantly reduced in the OE group (343.19±81.22 vs. 3.22±2.34; 40.53±14.02 vs. 15.68±9.36,Pï¼0.01). Conclusion: Overexpression of the Numb gene can inhibit CLF progression in the adult liver, which may become a new target for CLF therapy.
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Sistema Biliar , Colestasis , Ratas , Animales , Ratas Sprague-Dawley , Hígado/patología , Cirrosis Hepática/patología , Sistema Biliar/patología , Colestasis/patología , Ligadura , Ácidos y Sales Biliares/metabolismo , ARN Mensajero/metabolismo , Conductos Biliares/patología , Péptidos y Proteínas de Señalización Intracelular/metabolismoRESUMEN
Infrared (IR)-emitting RE doped materials have been extensively used to fabricate active components of integrated optical devices in various fields, such as fiber amplifiers, telecommunications, optoelectronics, and waveguides. Among various RE elements, trivalent erbium ions (Er 3+) are of great interest since their emissive behavior span the low loss telecommunication window of 1300-1650 nm. In this paper, we report two types of polymeric waveguide amplifiers. 8 cm long, lithographically patterned spiral waveguides provide 8 dB of gain using a 980 nm pump power of 95 mW. Gain is observed from 1530 to 1590 nm. We further report the first demonstration of polymeric waveguide amplifiers fabricated using 3D printing methods based on two-photon lithography, paving the way for rapid prototyping of active 3D printed devices and active photonic devices which may transcend planar limitations.
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To investigate the effectiveness and safety of ultrasound-guided microwave ablation (MWA) in treatment of primary hyperparathyroidism (PHPT). A total of 12 PHPT patients with parathyroid adenoma were treated with MWA in Nanjing University of Chinese Medicine Affiliated Hospital of Integrated Traditional Chinese and Western Medicine from May 2019 to February 2021. The patients were followed up once every 3 months for 3-12 months. Levels of serum parathyroid hormone (PTH), calcium and phosphorus were detected before and 20 min, 4h and 1day after ablation, and during follow-up period. The volume and volume reduction rate of parathyroid lesion were compared before the treatment and at the end of follow-up. The technical and clinical success of MWA were assessed as well. At the end of follow-up, median serum PTH [66.60 (42.21,80.03) ng/L vs.169.90 (89.01,396.50) ng/L] and calcium [2.39 (2.32,2.49) mmol/L vs. 2.75 (2.57,2.96) mmol/L] levels in 12 patients decreased significantly (all P<0.05). A complete response in terms of PTH and calcium levels was achieved in 6 of the 12 patients, while 4 of the patients had slightly elevated PTH levels just above the upper limit of normal reference range, and 2 of the patients remained abnormal PTH and calcium levels. The clinical cure rate was 50%. The volumes of all lesion after ablation were significantly decreased (P<0.05), with the technical success rate reaching 92.3%. No serious complications were observed. Ultrasound-guided MWA, thus, is safe and effective in the treatment of PHPT.
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Hiperparatiroidismo Primario , Neoplasias de las Paratiroides , Ablación por Radiofrecuencia , Calcio , Humanos , Hiperparatiroidismo Primario/diagnóstico por imagen , Hiperparatiroidismo Primario/cirugía , Microondas/uso terapéutico , Hormona Paratiroidea , Neoplasias de las Paratiroides/complicaciones , Neoplasias de las Paratiroides/diagnóstico por imagen , Neoplasias de las Paratiroides/cirugía , Ultrasonografía IntervencionalRESUMEN
Objective: To analyze the trend of mortality and incidence of colorectal cancer among urban residents in Guangzhou from 1972 to 2015 and to predict the mortality of colorectal cancer from 2016 to 2025. Methods: The mortality data of colorectal cancer among urban residents in Guangzhou were collected from the death registration of malignant tumors of Guangzhou Health Statistics Bureau (1972-1979), Guangzhou Health Statistics (1980-2001), Guangzhou Cancer Registration Annual Report (2002-2009) and China Cancer Registration Annual Report (2010-2015). The incidence of colorectal cancer was collected from Guangzhou Cancer Registration Annual Report (2002-2009) and China Cancer Registration Annual Report (2010-2015). The incidence and mortality data of colorectal cancer coded as C18-C21 in 10th Edition of International Classification of Diseases (ICD-10) were obtained from the above data, and the demographic data were from the Guangzhou Municipal Bureau of Statistics. Joinpoint model was used to calculate the annual change percentage (APC) and average annual change percentage (AAPC) of colorectal cancer mortality and incidence among urban residents in Guangzhou from 1972 to 2015 and from 2002 to 2015. ARIMA model was used to predict colorectal cancer mortality from 2016 to 2025. Results: There were 19 309 colorectal cancer deaths among urban residents in Guangzhou from 1972 to 2015. The crude mortality rate of colorectal cancer increased from 4.33/100 000 to 24.89/100 000 (AAPC=4.2%, P<0.001). A total of 24 033 new cases of colorectal cancer were reported in Guangzhou from 2002 to 2015. The crude incidence rate of colorectal cancer increased from 22.95/100 000 to 52.81/100 000 (AAPC=6.6%, P<0.001). The mortality rate of colorectal cancer among urban residents of Guangzhou would continuously increase from 2016 to 2025 and reach 29.53/100 000 in 2025. Conclusion: The mortality rate of colorectal cancer among urban residents of Guangzhou from 1972 to 2015 and the incidence rate of colorectal cancer from 2002 to 2015 both show an upward trend. The mortality rate will increase from 2016 to 2025.
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Neoplasias Colorrectales , Población Rural , China/epidemiología , Neoplasias Colorrectales/epidemiología , Humanos , Incidencia , Morbilidad , Población UrbanaRESUMEN
Interacting electrons confined to their lowest Landau level in a high magnetic field can form a variety of correlated states, some of which manifest themselves in a Hall effect. Although such states have been predicted to occur in three-dimensional semimetals, a corresponding Hall response has not yet been experimentally observed. Here, we report the observation of an unconventional Hall response in the quantum limit of the bulk semimetal HfTe5, adjacent to the three-dimensional quantum Hall effect of a single electron band at low magnetic fields. The additional plateau-like feature in the Hall conductivity of the lowest Landau level is accompanied by a Shubnikov-de Haas minimum in the longitudinal electrical resistivity and its magnitude relates as 3/5 to the height of the last plateau of the three-dimensional quantum Hall effect. Our findings are consistent with strong electron-electron interactions, stabilizing an unconventional variant of the Hall effect in a three-dimensional material in the quantum limit.
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OBJECTIVE: The World Health Organization reported a cluster of cases of pneumonia of unknown cause detected on December 31, 2019 in China. Unfortunately, a 34-year-old Italian nurse has committed suicide after testing positive for coronavirus. It was the second case of suicide by a nurse in an Italian hospital and occurred only a few days after the first suicide. These consecutive suicides have aroused concern, and it is necessary to investigate the psychological issues of the medical staff in Italy regarding the COVID-19.
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Infecciones por Coronavirus/terapia , Personal de Salud/psicología , Neumonía Viral/terapia , Suicidio/psicología , Betacoronavirus , COVID-19 , Humanos , Italia , Enfermeras y Enfermeros , Pandemias , SARS-CoV-2 , Prevención del SuicidioRESUMEN
OBJECTIVE: Obstructive Sleep Apnea Syndrome (OSAS) is a disorder characterized by recurrent upper airway obstruction, apnea, and hypopnea, associated with decreased oxygen saturation and disturbed sleep structure during sleep. It was found that OSAS was associated with a variety of arrhythmia and conduction disorders, but the relationship between multiple types of arrhythmia and the severity of OSAS, and its possible mechanism remain unclear. The purpose of this study was to observe the main types of arrhythmia and the condition of heart rate variability (HRV) in patients with OSAS, to detect the levels of multiple inflammatory factors in serum of OSAS patients, and to observe the correlation between polysomnographic parameters or inflammatory factors, and arrhythmia or HRV, as well as its possible mechanisms. PATIENTS AND METHODS: 141 patients with suspected OSAS were collected in the Second Affiliated Hospital of Soochow University and Xinghua People's Hospital from February 2016 to February 2018. According to the sleep apnea hypopnea index (AHI), they were divided into control group (AHI <5, n = 34), mild-moderate OSAS group (5≤ AHI <30, n = 48), and severe OSAS group (AHI ≥30, n = 59). Clinical data such as gender and age were collected. All patients completed polysomnography (PSG), 24-hour Holter monitoring and blood routine, biochemical indexes and serum hs-CRP, TNF-α, IL-6, and IL-1ß testing. The indicators in the three groups were compared, and the correlation between PSG parameters, HRV and inflammatory biomarkers was investigated. RESULTS: Compared with control group, there were significant differences in age, sex ratio, BMI, uric acid, TC, and TG in the mild-moderate OSAS group (p<0.05), and in age, sex ratio, BMI, red blood cell count, hemoglobin, hematocrit, uric acid, FBS, TC, TG, LDL, and HDL in severe OSAS group (p<0.05). There were significant differences in gender ratio, BMI, red blood cell count, hemoglobin, hematocrit, uric acid, FBS, TC, TG, LDL, and HDL between mild-moderate OSAS group and severe OSAS group (p<0.05). Heart rate variability (HRV) parameters include SDNN, SDNN index, RMSSD, PNN50, LF, HF, and LF/HF. SDNN, PNN50, and HF in severe OSAS group and mild-moderate OSAS group were significantly lower than those in control group (p<0.05). LF/HF was significantly higher than that of control group (p<0.05). There was a significant difference in PNN50, HF, and LF/HF between severe OSAS group and mild-moderate OSAS group (p<0.05). In terms of inflammation, serum hs-CRP was significantly higher in mild-moderate OSAS group and severe OSAS group than that in control group (p<0.05). Serum IL-1ß was significantly higher in mild-moderate OSAS group than that in severe OSAS group (p<0.05). There was no significant difference in other indicators (p>0.05). There was a significant positive correlation between hs-CRP and oxygen reduction index (ODI) (r=0.209, p=0.013) and a significant negative correlation with PNN50 (r=-0.188, p=0.025). There is no significant correlation between other indicators. CONCLUSIONS: Systemic inflammatory reactions existed in patients with OSAS. With the increase of OSAS, inflammation was aggravated, especially serum hs-CRP. Hs-CRP was significantly and negatively correlated with PNN50 and positively correlated with ODI. The results suggested that the inflammatory response was involved in the occurrence of heart rate variability in OSAS patients.
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Arritmias Cardíacas/sangre , Inflamación/sangre , Apnea Obstructiva del Sueño/sangre , Adulto , Anciano , Arritmias Cardíacas/diagnóstico , Biomarcadores/sangre , Biomarcadores/metabolismo , Proteína C-Reactiva/análisis , Proteína C-Reactiva/metabolismo , Femenino , Frecuencia Cardíaca , Humanos , Inflamación/metabolismo , Interleucina-1beta/sangre , Interleucina-1beta/metabolismo , Interleucina-6/sangre , Interleucina-6/metabolismo , Masculino , Persona de Mediana Edad , Oxígeno/sangre , Oxígeno/metabolismo , Apnea Obstructiva del Sueño/diagnóstico , Factor de Necrosis Tumoral alfa/sangre , Factor de Necrosis Tumoral alfa/metabolismo , Adulto JovenRESUMEN
A Cr3Al compound with a DO3 structure has previously been predicted to be nearly half metal and a promising spintronics material; however, its synthesis has not been reported. Here, a Cr3Al compound with a DO3 structure is successfully prepared in thin-film form by the magnetron sputtering method. It was found that the substrate temperature is crucial to the atomic ordering, thin-film density and lattice constant. The lattice constant varies with different substrate temperatures and is smaller than the theoretical equilibrium lattice constant. Theoretical investigations on the electronic structures and magnetic properties indicate that the Cr3Al compound with a DO3 structure is a rare material with zero-gap half-metallic characteristics under an experimental lattice constant of 5.83â Å. The experimental result is in agreement with the theoretical results in magnetization, and the Cr3Al compound synthesized in this work exhibits semi-metallic-like electrical transport characteristics and positive magnetoresistance of greater than 2% in the temperature range 2-250â K.
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We investigate polarization-dependent ultrafast photocurrents in the Weyl semimetal TaAs using terahertz (THz) emission spectroscopy. Our results reveal that highly directional, transient photocurrents are generated along the noncentrosymmetric c axis regardless of incident light polarization, while helicity-dependent photocurrents are excited within the ab plane. This is consistent with earlier static photocurrent experiments, and demonstrates on the basis of both the physical constraints imposed by symmetry and the temporal dynamics intrinsic to current generation and decay that optically induced photocurrents in TaAs are inherent to the underlying crystal symmetry of the transition metal monopnictide family of Weyl semimetals.
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We present an infrared spectroscopy study of ZrTe_{5}, which confirms a recent theoretical proposal that this material exhibits a temperature-driven topological quantum phase transition from a weak to a strong topological insulating state with an intermediate Dirac semimetal state around T_{p}≃138 K. Our study details the temperature evolution of the energy gap in the bulk electronic structure. We found that the energy gap closes around T_{p}, where the optical response exhibits characteristic signatures of a Dirac semimetal state, i.e., a linear frequency-dependent optical conductivity extrapolating to the origin (after subtracting a weak Drude response). This finding allows us to reconcile previous diverging reports about the topological nature of ZrTe_{5} in terms of a variation of T_{p} that depends on the crystal growth condition.
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We report on the design and experimental demonstration of a broadband silicon polarization beam splitter (PBS) with a high extinction ratio (ER)≥30 dB. This was achieved using triple-bent-waveguide directional coupling in a single PBS, and cascaded PBS topology. For the single PBS, the bandwidths for an ER≥30 dB are 20 nm for the quasi-TE mode, and 70 nm for the quasi-TM mode when a broadband light source (1520-1610 nm) was employed. The insertion loss (IL) varies from 0.2 to 1 dB for the quasi-TE mode and 0.2-2 dB for the quasi-TM mode. The cascaded PBS improved the bandwidth of the quasi-TE mode for an ER≥30 dB to 90 nm, with a low IL of 0.2-2 dB. To the best of our knowledge, our PBS system is one of the best broadband PBSs with an ER as high as â¼42 dB and a low IL below 1 dB around the central wavelength, and experimentally demonstrated using edge-coupling.
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Objective: The Notch signaling pathway is closely related to biliary fibrosis. Previous studies have shown that Astragaloside (AS) can prevent the progression of cholestatic liver fibrosis. The purpose of this study is to observe the effect of AS on the regulation of Notch signaling pathway in biliary fibrosis. Methods: Cholestatic liver fibrosis was established by common bile duct ligation (BDL) in rats. Two weeks after BDL, the rats were randomly divided into a model group (i.e., BDL), an Astragalosides group (AS), and a sorafenib (SORA) positive control group and treated for 3 weeks. Bile duct proliferation and liver fibrosis were determined by tissue staining. Protein and gene expression were determined by immunostaining, immunoblotting and RT-PCR, respectively. Activation of the Notch signaling pathway was evaluated by analyzing expressions of Notch-1, -2, -3, -4, Jagged (JAG)1, Delta like (DLL)-1, -3, -4, Hes1, Numb and RBP-Jκ. Statistical analysis of variance analysis, q test, P < 0.05 showed that the difference was statistically significant. Results: (1) AS significantly reduced the deposition of collagen and the Hyp content of liver tissue (500.15 ± 86.10 vs. 625.72 ± 105.62, P = 0.031), and inhibited the activation of hepatic stellate cells. (2) AS significantly decreased the protein and mRNA expressions of transforming growth factor (TGF)-ß1 (1.02±0.15 vs. 1.89±0.36, P = 0.007; 1.17±0.18 vs. 1.68±0.29, P = 0.013, respectively) and α-smooth muscle actin (α-SMA, 0.41±0.11 vs. 0.72±0.16, P = 0.003; 1.71±0.57 vs. 2.68±0.46, P = 0.008, respectively) compared with BDL group. In contrast, AS significantly enhanced expression of the Smad 7 protein compared with the BDL group (0.72±0.008 vs. 0.33±0.001, P = 0.005). AS also reduced biliary epithelial cell proliferation. AS reduced the mRNA levels of CK7, CK8 and CK18 (1.31±0.39 vs. 2.63±0.82, P = 0.009; 0.71±0.09 vs. 0.87±0.08, P = 0.031; 2.56±0.32 vs. 3.41±0.39, P = 0.010, respectively) and reduced the positive areas of CK19 and OV6 (62 337.17±21 873.38 vs. 22 5472.67±26 933.63, P = 0.000; 92 237.43±15 894.11 vs. 171 298.13±61 761.37, P = 0.000, respectively). (3) The mRNA expression of Notch-2, -3, -4 and JAG1 were significantly reduced in the AS group compared to the BDL group (1.07±0.19 vs. 1.51±0.28, P = 0.044; 0.99±0.24 vs. 1.18±0.10, P = 0.043; 1.36±0.42 vs. 3.40±0.44, P = 0.048; 2.62±0.43 vs. 3.73±0.83, P = 0.046, respectively). In contrast, the mRNA level of Numb was clearly enhanced after AS treatment (0.90±0.05 vs. 0.75±0.11, P = 0.019). In addition, consistent with the mRNA levels, the protein expressions of Notch-2, -3, -4 and JAG1 were reduced significantly (1.27±0.18 vs. 1.71±0.26, P = 0.004; 0.99±0.11 vs. 4.38±0.60, P = 0.001; 1.76±0.32 vs. 4.01±0.74, P = 0.002; 1.62±0.33 vs. 2.74±0.63, P = 0.002) and the Numb protein level was increased significantly (1.50±0.15 vs. 0.85±0.11, P = 0.001) in AS group compared with BDL group. Conclusion: AS may prevent cholestatic liver fibrosis via inhibition of the Notch signaling pathway, thereby inhibiting the abnormal proliferation of biliary epithelial cells. Results indicate that AS may be a potential treatment for cholestatic liver disease.