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6,638 result(s) for "Qian, L"
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Prognostic nomogram for overall survival in previously untreated patients with extranodal NK/T-cell lymphoma, nasal-type: a multicenter study
The aim of this study was to develop a widely accepted prognostic nomogram for extranodal NK/T-cell lymphoma, nasal-type (NKTCL). The clinical data from 1383 patients with NKTCL treated at 10 participating institutions between 2000 and 2011 were reviewed. A nomogram was developed that predicted overall survival (OS) based on the Cox proportional hazards model. To contrast the utility of the nomogram against the widely used Ann Arbor staging system, the International Prognostic Index (IPI) and the Korean Prognostic Index (KPI), we used the concordance index (C-index) and a calibration curve to determine its predictive and discriminatory capacity. The 5-year OS rate was 60.3% for the entire group. The nomogram included five important variables based on a multivariate analysis of the primary cohort: stage; age; Eastern Cooperative Oncology Group performance status; lactate dehydrogenase; and primary tumor invasion. The calibration curve showed that the nomogram was able to predict 5-year OS accurately. The C-index of the nomogram for OS prediction was 0.72 for both cohorts, which was superior to the predictive power (range, 0.56–0.64) of the Ann Arbor stage, IPI and KPI in the primary and validation cohorts. The proposed nomogram provides an individualized risk estimate of OS in patients with NKTCL.
Discrimination of Smoke-Exposed Pinot Noir Wines by Volatile Phenols and Volatile Phenol-Glycosides
This study investigated the correlation between five primary volatile phenols (VPs) and their glycosides in smoke-exposed and non-smoke-exposed Pinot noir wines to assess and identify potential markers for smoke taint. The results showed that all putative VP-glycosides in smoke-exposed wines were higher than in non-smoke-exposed wines, with a fold change ranging from 2.11 to 31.88 for the top fifteen differentiations. VP-glycosides showed strong positive correlations among themselves, with correlation coefficients of 0.94 for hexose-guaiacol vs. pentose (P)-hexose (H)-cresol and 0.92 for syringyl-β-D-glucopyranoside vs. H-P-4-methylguaiacol. VP-glycosides also showed relatively high correlations with free and strong acid-hydrolyzed VPs. The correlation coefficient between H-P-guaiacol and free-form guaiacol is 0.71, and between H-P-guaiacol and total guaiacol is 0.78. The strong correlation suggests that these compounds are interconnected and regulated by the severity of smoke exposure. Multivariate analysis effectively differentiated smoke-exposed wines from non-smoke-exposed ones. However, more research is needed to fill the gaps in understanding smoke-derived compounds.
Stat3-coordinated Lin-28–let-7–HMGA2 and miR-200–ZEB1 circuits initiate and maintain oncostatin M-driven epithelial–mesenchymal transition
Inflammation can act as a crucial mediator of epithelial-to-mesenchymal transition (EMT). In this study, we show that oncostatin M (OSM) is expressed in an autocrine/paracrine fashion in invasive breast carcinoma. OSM stimulation promotes spontaneous lung metastasis of MCF-7 xenografts in nude mice. A conspicuous epigenetic transition was induced by OSM stimulation not only in breast cancer cell lines but also in MCF-7 xenografts in nude mice. The expression of miR-200 and let-7 family members in response to OSM stimulation was downregulated in a signal transducer and activator of transcription factor 3 (Stat3)-dependent manner, resulting in comprehensive alterations of the transcription factors and oncoproteins targeted by these microRNAs. Inhibition of Stat3 activation or the ectopic expression of let-7 and miR-200 effectively reversed the mesenchymal phenotype of breast cancer cells. Stat3 promotes the transcription of Lin-28 by directly binding to the Lin-28 promoter, resulting in the repression of let-7 expression and concomitant upregulation of the let-7 target, high-mobility group A protein 2 (HMGA2). Knock down of HMGA2 significantly impairs OSM-driven EMT. Our data indicate that downregulation of let-7 and miR-200 levels initiates and maintains OSM-induced EMT phenotypes, and HMGA2 acts as a master switch of OSM-induced EMT. These findings highlight the importance of Stat3-coordinated Lin-28B–let-7–HMGA2 and miR-200–ZEB1 circuits in the cytokine-mediated phenotypic reprogramming of breast cancer cells.
A bimodal burst energy distribution of a repeating fast radio burst source
The event rate, energy distribution and time-domain behaviour of repeating fast radio bursts (FRBs) contain essential information regarding their physical nature and central engine, which are as yet unknown 1 , 2 . As the first precisely localized source, FRB 121102 (refs. 3 – 5 ) has been extensively observed and shows non-Poisson clustering of bursts over time and a power-law energy distribution 6 – 8 . However, the extent of the energy distribution towards the fainter end was not known. Here we report the detection of 1,652 independent bursts with a peak burst rate of 122 h −1 , in 59.5 hours spanning 47 days. A peak in the isotropic equivalent energy distribution is found to be approximately 4.8 × 10 37 erg at 1.25 GHz, below which the detection of bursts is suppressed. The burst energy distribution is bimodal, and well characterized by a combination of a log-normal function and a generalized Cauchy function. The large number of bursts in hour-long spans allows sensitive periodicity searches between 1 ms and 1,000 s. The non-detection of any periodicity or quasi-periodicity poses challenges for models involving a single rotating compact object. The high burst rate also implies that FRBs must be generated with a high radiative efficiency, disfavouring emission mechanisms with large energy requirements or contrived triggering conditions. For FRB 121102, 1,652 burst events are detected over 47 days, with a peak burst rate of 122 per hour, a bimodal burst rate energy distribution, and no periodicity or quasi-periodicity.
A hybrid ensemble method for pulsar candidate classification
In this paper, three ensemble methods: Random Forest, XGBoost, and a Hybrid Ensemble method were implemented to classify imbalanced pulsar candidates. To assist these methods, tree models were used to select features among 30 features of pulsar candidates from references. The skewness of the integrated pulse profile, chi-squared value for sine-squared fit to amended profile and best S/N value play important roles in Random Forest, while the skewness of the integrated pulse profile is one of the most significant features in XGBoost. More than 20 features were selected by their relative scores and then applied in three ensemble methods. In the Hybrid Ensemble method, we combined Random Forest and XGBoost with EasyEnsemble. By changing thresholds, we tried to make a trade-off between Recall and Precision to make them approximately equal and as high as possible. Experiments on HTRU 1 and HTRU 2 datasets show that the Hybrid Ensemble method achieves higher Recall than the other two algorithms. In HTRU 1 dataset, Recall, Precision, and F-Score of the Hybrid Ensemble method are 0.967, 0.971, and 0.969, respectively. In HTRU 2 dataset, the three values of that are 0.920, 0.917, and 0.918, respectively.
Equinox Transitions of Thermosphere O/N2 and Meridional Circulation in the Northern Hemisphere as Observed by NASA's GOLD and ICON Missions
Leveraging the unique perspective enabled by Global‐scale Observations of the Limb and Disk, we examined the characteristics of equinox transitions in the thermospheric column integrated ratio of atomic oxygen to molecular nitrogen (O/N2) in the Northern Hemisphere. We found that the timing of the O/N2 equinox transition from winter to summer or vice versa exhibits a progression with latitude, particularly, near spring equinox. The O/N2 equinox transition is far slower during spring compared to fall, leading to a remarkable seasonal asymmetry. Ionospheric Connection Explorer observed a prominent asymmetry in the summer‐to‐winter circulation in the middle to upper thermosphere, implying that the inter‐hemispheric circulation plays a crucial role in the O/N2 equinox transition. Additionally, since the wave‐driven meridional circulation in the lower thermosphere displays a seasonal asymmetry between the northward‐to‐southward and southward‐to‐northward transitions, we would anticipate that the O/N2 equinox transition is also influenced by the lower atmospheric forcing.
Smoked-Derived Volatile Phenol Analysis in Wine by Stir Bar Sorptive Extraction-Gas Chromatography-Mass Spectrometry
Smoke-derived taint has become a significant concern for the U.S. wine industry, particularly on the west coast, and climate change is anticipated to aggravate it. High volatile phenols such as guaiacol, 4-methylguaiacol, 4-ethylguaiacol, 4-ethylphenol, and o-, p-, m-cresols have been suggested to be related to smoke-exposed grape and wine. This paper describes an analytical approach based on ethylene glycol/polydimethylsiloxane (EG/PDMS)-stir bar sorptive extraction-gas chromatography-mass spectrometry (SBSE-GC-MS) to quantify or estimate the concentrations of some smoke-related volatile phenols in wines. Correlation coefficients with R2 ≥ 0.990 were obtained. This method can quantify most smoked-related volatile phenols down to 0.5 μg/L in wine in selective ion monitoring mode. Recovery for the targeted volatile phenols ranged from 72.2% to 142.4% in the smoke-tainted wine matrix, except for 4-vinylguaiacol. The standard deviations of the volatile phenols were from 0 to 23% in smoke-tainted wine. The approach provides another tool to evaluate wine smoke exposure and potential smoke taint.
Diverse polarization angle swings from a repeating fast radio burst source
Fast radio bursts (FRBs) are millisecond-duration radio transients 1 , 2 of unknown origin. Two possible mechanisms that could generate extremely coherent emission from FRBs invoke neutron star magnetospheres 3 – 5 or relativistic shocks far from the central energy source 6 – 8 . Detailed polarization observations may help us to understand the emission mechanism. However, the available FRB polarization data have been perplexing, because they show a host of polarimetric properties, including either a constant polarization angle during each burst for some repeaters 9 , 10 or variable polarization angles in some other apparently one-off events 11 , 12 . Here we report observations of 15 bursts from FRB 180301 and find various polarization angle swings in seven of them. The diversity of the polarization angle features of these bursts is consistent with a magnetospheric origin of the radio emission, and disfavours the radiation models invoking relativistic shocks. Polarization observations of the fast radio burst FRB 180301 with the FAST radio telescope show diverse polarization angle swings, consistent with a magnetospheric origin of the emission.
GOLD Synoptic Observations of Quasi-6-Day Wave Modulations of Post-Sunset Equatorial Ionization Anomaly During the September 2019 Antarctic Sudden Stratospheric Warming
Using observations from the Global-scale Observations of the Limb and Disk (GOLD) mission, we investigate post-sunset ionospheric responses to the September 2019 Antarctic sudden stratospheric warming –first ever from a synoptic perspective. Observations reveal a prevalent quasi-6-day periodicity in the equatorial ionization anomaly region over South America and the Atlantic, coincident with enhanced quasi-6-day wave (Q6DW) activity in the mesosphere (Liu et al., 2021, https://doi.org/10.1029/2020JA028909). The atmosphere-ionosphere coupling via large-scale waves is rarely studied over the ocean due to the lack of observations. More importantly, further analyses suggest that multiple pathways are involved in transmitting the quasi-6-day periodicity from the middle atmosphere into the post-sunset F-region ionosphere, including modulation of F-region field aligned winds and pre-reversal enhancements by the tides and or Q6DW. A remarkable depletion in electron density, attributable to the overall change in thermosphere composition driven by the dissipative tides and or Q6DWs, is also seen during the period of enhanced Q6DW activity.
Beyond potency: A proposed lexicon for sensory differentiation of Cannabis sativa L. aroma
Aroma is a critical factor in consumer-perceived quality of Cannabis sativa L., yet standardized tools for describing the aromatic diversity of uncombusted Cannabis inflorescence are lacking. This study generated and evaluated a descriptive aroma lexicon for intact Cannabis inflorescence consisting of 25 terms with defined reference standards. A human panel evaluated 91 samples using a Check-All-That-Apply method. Multivariate analyses demonstrated the lexicon’s ability to differentiate samples based on orthonasal aroma. Type I and III Cannabis exhibited overlapping sensory profiles, though type I (high THC, low CBD) was more frequently described as skunky , musty , and animalic , whereas type III (low THC, high CBD) had higher frequencies of citrus , fruity , and candy -like aromas. Terpene profiling revealed clear chemical clusters, but terpene profiles alone poorly predicted sensory character. Terpinolene was the only compound consistently associated with sensory descriptors, specifically citrus and chemical . In type III samples, 43 volatile sulfur compounds were detected via gas chromatography with a pulsed flame photometric detector, including dimethyl sulfide, methional, and dimethyl trisulfide while others were tentatively identified or novel. However, neither terpene nor volatile sulfur compound profiles strongly predicted sensory perception. These results emphasize the limitations of chemical composition as a proxy for aroma quality. This work establishes a foundation for future research linking aroma, chemistry, and consumer preferences, and supports the development of quality metrics beyond delta-9-tetrahydrocannabinol potency.