31 research outputs found
Relationship of the metabolic score for insulin resistance and the risk of stroke in patients with hypertension: A cohort study
BackgroundThe current status of the dose-response relationship between the metabolic score for insulin resistance (METS-IR) and new-onset stroke in hypertensive patients and its subtypes is unclear. This study aimed to determine the association between METS-IR and incident stroke and its subtypes within a cohort of Chinese hypertensive patients.MethodsA total of 14032 hospitalized patients with hypertension from January 1, 2010, to December 31, 2021, were included in this retrospective cohort study. Cox models and restricted cubic splines were applied to determine the association between METS-IR and the risk of stroke.ResultsDuring a median follow-up of 4.80 years, 1067 incident stroke cases occurred. Patients in the highest quartile group of METS-IR levels exhibited a higher risk of stroke (HR, 1.80; 95% CI, 1.50-2.17) and ischemic stroke (HR, 1.96; 95% CI, 1.60–2.42) than those in the lowest quartile group. However, no significant associations were observed between METS-IR and the risk of hemorrhagic stroke. Restricted cubic spline analysis suggested a nearly J-shaped association between METS-IR and risk of stroke and ischemic stroke (P for nonlinearity < 0.001). METS-IR did produce a significant improvement in the C statistic when added to the basic model (from 0.637 to 0.664, P < 0.001). Notably, the addition of METS-IR to the basic model resulted in a significant improvement in predicting incident total stroke and ischemic stroke.ConclusionsThis cohort study suggests a relationship between METS-IR and the risk of stroke and ischemic stroke. Further studies are required to elucidate the underlying mechanisms
Deconfined quantum critical point lost in pressurized SrCu2(BO3)2
In the field of correlated electron materials, the relation between the
resonating spin singlet and antiferromagnetic states has long been an
attractive topic for understanding of the interesting macroscopic quantum
phenomena, such as the ones emerging from magnetic frustrated materials,
antiferromagnets and high-temperature superconductors. SrCu2(BO3)2 is a
well-known quantum magnet, and it is theoretically expected to be the candidate
of correlated electron material for clarifying the existence of a
pressure-induced deconfined quantum critical point (DQCP), featured by a
continuous quantum phase transition, between the plaquette-singlet (PS) valence
bond solid phase and the antiferromagnetic (AF) phase. However, the real nature
of the transition is yet to be identified experimentally due to the technical
challenge. Here we show the experimental results for the first time, through
the state-of-the-art high-pressure heat capacity measurement, that the PS-AF
phase transition of the pressurized SrCu2(BO3)2 at zero field is clearly a
first-order one. Our result clarifies the more than two-decade long debates
about this key issue, and resonates nicely with the recent quantum entanglement
understanding that the theoretically predicted DQCPs in representative lattice
models are actually a first-order transition. Intriguingly, we also find that
the transition temperatures of the PS and AF phase meet at the same
pressure-temperature point, which signifies a bi-critical point as those
observed in Fe-based superconductor and heavy-fermion compound, and constitutes
the first experimental discovery of the pressure-induced bi-critical point in
frustrated magnets. Our results provide fresh information for understanding the
evolution among different spin states of correlated electron materials under
pressure.Comment: 6 pages, 4 figure
Association between Use of Spironolactone and Risk of Stroke in Hypertensive Patients: A Cohort Study
Objective: to investigate the relationship between the use of spironolactone and the risk of stroke in hypertensive patients. Methods: a total of 2464 spironolactone users and 12,928 non-users were identified (unmatched original cohort), and 1:1 matched pairs of 2461 spironolactone users and 2461 non-users based on propensity scores were created (propensity-score-matched cohort). Results: In the unmatched original cohort, the unadjusted analysis showed that the use of spironolactone was associated with a lower risk of total stroke (HR, 0.71; 95% CI, 0.61–0.84; p < 0.001), which was sustained in the adjusted analysis. According to stroke type, the association was with ischemic strokes (propensity-score-adjusted HR, 0.71; 95% CI, 0.59–0.85; p < 0.001) and hemorrhagic ones (propensity-score-adjusted HR, 0.63; 95% CI, 0.45–0.88; p = 0.008). Similar results were shown in the propensity-score-matched cohort. The results of the subgroup and sensitivity analyses were consistent with those of the primary analysis. The dose–response analysis demonstrated a dose-dependent association of spironolactone with a lower risk of stroke in hypertensive patients. Conclusions: The use of spironolactone was associated with a significantly lower risk of stroke events in hypertensive patients. Further research, including prospective randomized clinical trials, is needed to validate our findings
Control of the Longitudinal Compression and Transverse Focus of Ultrafast Electron Beam for Detecting the Transient Evolution of Materials
Ultrafast detection is an effective method to reveal the transient evolution mechanism of materials. Compared with ultra-fast X-ray diffraction (XRD), the ultra-fast electron beam is increasingly adopted because the larger scattering cross-section is less harmful to the sample. The keV single-shot ultra-fast electron imaging system has been widely used with its compact structure and easy integration. To achieve both the single pulse imaging and the ultra-high temporal resolution, magnetic lenses are typically used for transverse focus to increase signal strength, while radio frequency (RF) cavities are generally utilized for longitudinal compression to improve temporal resolution. However, the detection signal is relatively weak due to the Coulomb force between electrons. Moreover, the effect of RF compression on the transverse focus is usually ignored. We established a particle tracking model to simulate the electron pulse propagation based on the 1-D fluid equation and the 2-D mean-field equation. Under considering the relativity effect and Coulomb force, the impact of RF compression on the transverse focus was studied by solving the fifth-order Rung–Kutta equation. The results show that the RF cavity is not only a key component of longitudinal compression but also affects the transverse focusing. While the effect of transverse focus on longitudinal duration is negligible. By adjusting the position and compression strength of the RF cavity, the beam spot radius can be reduced from 100 μm to 30 μm under the simulation conditions in this paper. When the number of single pulse electrons remains constant, the electrons density incident on the sample could be increased from 3.18×1012 m−2 to 3.54×1013 m−2, which is 11 times the original. The larger the electron density incident on the sample, the greater the signal intensity, which is more conducive to detecting the transient evolution of the material
Association between Use of Spironolactone and Risk of Stroke in Hypertensive Patients: A Cohort Study
Objective: to investigate the relationship between the use of spironolactone and the risk of stroke in hypertensive patients. Methods: a total of 2464 spironolactone users and 12,928 non-users were identified (unmatched original cohort), and 1:1 matched pairs of 2461 spironolactone users and 2461 non-users based on propensity scores were created (propensity-score-matched cohort). Results: In the unmatched original cohort, the unadjusted analysis showed that the use of spironolactone was associated with a lower risk of total stroke (HR, 0.71; 95% CI, 0.61–0.84; p p p = 0.008). Similar results were shown in the propensity-score-matched cohort. The results of the subgroup and sensitivity analyses were consistent with those of the primary analysis. The dose–response analysis demonstrated a dose-dependent association of spironolactone with a lower risk of stroke in hypertensive patients. Conclusions: The use of spironolactone was associated with a significantly lower risk of stroke events in hypertensive patients. Further research, including prospective randomized clinical trials, is needed to validate our findings
Effects of Atomic Ratio on the Mechanical Properties of Amorphous Silicon Carbon Nitride
This paper evaluates the mechanical properties of amorphous silicon carbon nitride (a-SiCxNy) films with different atomic ratios via molecular dynamics simulation. The Si-C-N ternary amorphous model is constructed using ReaxFF potential and melt-quenching method. The results demonstrate that the density range of constructed model spans a wide range of densities (2.247–2.831 g/cm3). The short- and medium-range order of the constructed a-SiCxNy structures show a good correlation with the experimental observations. Based on the structural feasibility, the elastoplastic performance is analyzed. There is significant ductility during the uniaxial tension process of a-SiCxNy, except for Si(CN2)2. The calculated elastic modulus ranges from 206.80 GPa to 393.58 GPa, close to the experimental values of coating films. In addition, the elastic modulus of a-SiCxNy does not change monotonically with the carbon or silicon content but is related to the atomic ratio. This article provides an understanding of the chemical composition dependence of the mechanical properties of amorphous compounds at the molecular level
A Nomogram Model Based on Noninvasive Bioindicators to Predict 3-Year Risk of Nonalcoholic Fatty Liver in Nonobese Mainland Chinese: A Prospective Cohort Study
The purpose of this study is to establish and validate an accurate and personalized nonalcoholic fatty liver disease (NAFLD) prediction model based on the nonobese population in China. This study is a secondary analysis of a prospective study. We included 6,155 nonobese adults without NAFLD at baseline, with a median follow-up of 2.3 years. Univariate and multivariate Cox regression analyses were used to determine independent predictors. The least absolute shrinkage and selection operator (LASSO) regression analysis was used to optimize the selection of variables. Based on the results of multivariate analysis, a prediction model was established. Harrell’s consistency index (C-index) and area under the curve (AUC) were used to determine the discrimination of the proposed model. The goodness of fit of the calibration model was tested, and the clinical application value of the model was evaluated by decision curve analysis (DCA). The participants were randomly divided into a training cohort (n=4,605) and a validation cohort (n=1,550). Finally, seven of the variables (HDL-c, BMI, GGT, ALT, TB, DBIL, and TG) were included in the prediction model. In the training cohort, the C-index and AUC value of this prediction model were 0.832 (95% confidence interval (CI), 0.820-0.844) and 0.861 (95% CI, 0.849-0.873), respectively. In the validation cohort, the C-index and AUC values of this prediction model were 0.829 (95% CI, 0.806-0.852) and 0.859 (95% CI, 0.841-0.877), respectively. The calibration plots demonstrated good agreement between the estimated probability and the actual observation. DCA demonstrated a clinically effective predictive model. Our nomogram can be used as a simple, reasonable, economical, and widely used tool to predict the 3-year risk of NAFLD in nonobese populations in China, which is helpful for timely intervention and reducing the incidence of NAFLD
Development and Validation of a Novel Model for Predicting the 5-Year Risk of Type 2 Diabetes in Patients with Hypertension: A Retrospective Cohort Study
Background. Hypertension is now common in China. Patients with hypertension and type 2 diabetes are prone to severe cardiovascular complications and poor prognosis. Therefore, this study is aimed at establishing an effective risk prediction model to provide early prediction of the risk of new-onset diabetes for patients with a history of hypertension. Methods. A LASSO regression model was used to select potentially relevant features. Univariate and multivariate Cox regression analyses were used to determine independent predictors. Based on the results of multivariate analysis, a nomogram of the 5-year incidence of T2D in patients with hypertension in mainland China was established. The discriminative capacity was assessed by Harrell’s C-index, AUC value, calibration plot, and clinical utility. Results. After random sampling, 1273 and 415 patients with hypertension were included in the derivation and validation cohorts, respectively. The prediction model included age, body mass index, FPG, and TC as predictors. In the derivation cohort, the AUC value and C-index of the prediction model are 0.878 (95% CI, 0.861-0.895) and 0.862 (95% CI, 0.830-0.894), respectively. In the validation cohort, the AUC value and C-index of the prediction model were 0.855 (95% CI, 0.836-0.874) and 0.841 (95% CI, 0.817-0.865), respectively. The calibration plots demonstrated good agreement between the estimated probability and the actual observation. Decision curve analysis shows that nomograms are clinically useful. Conclusion. Our nomogram can be used as a simple, affordable, reasonable, and widely implemented tool to predict the 5-year T2D risk of hypertension patients in mainland China. This application helps timely intervention to reduce the incidence of T2D in patients with hypertension in mainland China
Multiphoton Absorption Simulation of Sapphire Substrate under the Action of Femtosecond Laser for Larger Density of Pattern-Related Process Windows
It is essential to develop pattern-related process windows on substrate surface for reducing the dislocation density of wide bandgap semiconductor film growth. For extremely high instantaneous intensity and excellent photon absorption rate, femtosecond lasers are currently being increasingly adopted. However, the mechanism of the femtosecond laser developing pattern-related process windows on the substrate remains to be further revealed. In this paper, a model is established based on the Fokker–Planck equation and the two-temperature model (TTM) equation to simulate the ablation of a sapphire substrate under the action of a femtosecond laser. The transient nonlinear evolutions such as free electron density, absorption coefficient, and electron–lattice temperature are obtained. This paper focuses on simulating the multiphoton absorption of sapphire under femtosecond lasers of different wavelengths. The results show that within the range of 400 to 1030 nm, when the wavelength is large, the number of multiphoton required for ionization is larger, and wider and shallower ablation pits can be obtained. When the wavelength is smaller, the number of multiphoton is smaller, narrower and deeper ablation pits can be obtained. Under the simulation conditions presented in this paper, the minimum ablation pit depth can reach 0.11 μm and the minimum radius can reach 0.6 μm. In the range of 400 to 1030 nm, selecting a laser with a shorter wavelength can achieve pattern-related process windows with a smaller diameter, which is beneficial to increase the density of pattern-related process windows on the substrate surface. The simulation is consistent with existing theories and experimental results, and further reveals the transient nonlinear mechanism of the femtosecond laser developing the pattern-related process windows on the sapphire substrate
MMR gene patterns evaluation provides novel insights for personalized immunotherapy compared to neoadjuvant chemotherapy in lung adenocarcinama
Abstract Background The association involving mismatch repair (MMR) genes, molecular subtype and specific immune cell group in tumor microenvironment has been focused by more recent studies. Its prognosis value in lung adenocarcinoma (LUAD) neoadjuvant chemotherapy remains elusive. Methods The correlation between the MMR gene patterns and the immune landscape were comprehensively evaluated. The MMRScore was calculated using principal component analysis (PCA) after grouping using R/mclust package. The prognostic significance of the MMRScore was evaluated by Kaplan-merrier analysis. Then a cohort of 103 Chinese LUAD patients was collected for neoadjuvant chemotherapy prognosis evaluation and validation using MMRScore. Results Four MMRclusters (mc1, 2, 3, 4)-characterized by differences in extent of aneuploidy, expression of immunomodulatory (IM) genes, mRNA expression, lncRNA expression and prognosis were identified. We established MMRscore to quantify the MMR pattern of individual LUAD patients. As is shown in further analyses, the MMRscore was a potential independent prognostic factor of LUAD. Finally, the prognostic value of the MMRscore and its association with tumor immune microenvironment (TIME) of LUAD were verified in Chinese LUAD cohort. Conclusions We demonstrated the correlation between MMR gene pattern, the CNV and tumor immune landscape in LUAD. A MMRcluster mc2 with high MMRscore, high TMB and high CNV subtype was identified with poor prognosis and infiltrating immunocyte. The comprehensive evaluation of MMR patterns in individual LUAD patients enhances the understanding of TIME and gives a new insight toward improved immune treatment strategies for LUAD patients compared to neoadjuvant chemotherapy