The chemical composition of hazelnut kernels (
L.) and their COX-2 inhibitory, antimicrobial, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) ...(ABTS) radical-scavenging activities were investigated. Six previously undescribed indoleacetic acid glycosides, hazelnutins A-F (
-
), and five known compounds (
-
) were isolated from the hazelnut kernels. The structures of compounds
-
were successfully identified by high-resolution-electrospray ionization-mass spectrometry and NMR data, and their absolute configurations were established by electron-capture detector spectroscopy analyses in corporation with quantum chemical calculations. Furthermore, the absolute configurations of compounds
and
were unambiguously confirmed for the first time. Compounds
-
were discovered in hazelnut kernels for the first time. Compounds
-
inhibited COX-2 expression with inhibition rates ranging from 36.10 to 64.08%. Compounds
,
, and
could inhibit the proliferation of
. Compound
exhibited potent antioxidant activity against ABTS and DPPH with IC
values of 11.22 and 13.21 μmol/L, respectively. Compounds
and
exhibited moderate antioxidant activity against ABTS.
Building on the stakeholder-management and legitimacy literature, we argue that concern about stakeholders' reactions may cause firms to keep silent about their charitable donations. This study ...attempted to determine the influence of silent charitable donations on firm performance and its size and CEO salary. The sample of this study was listed non-state-owned enterprises (non-SOE) in China from 2009 to 2015 that make donations and do not include these philanthropic donations information in CSR reports. Data were collected from multiple sources, including the CSMAR database and the annual and CSR reports of the selected firms. The regression model was used to test the main effect. Results show that the silent donations of firms positively influence their performance. Moreover, firm size and CEO salary oppositely moderate the relationship between silent donations and firm performance. This study advances our understanding of how and under what conditions non-SOEs make silent charitable donations and enhance their performance by highlighting the important role of these donations, thereby contributing to the literature on corporate social responsibility and silent charitable donations.
The number of mass shootings in the United States has increased in the recent decades. Understanding the future risk of the mass shootings is critical for designing strategies to mitigate the risk of ...mass shootings, and part of understanding the future risk is to forecast the frequency or number of mass shootings in the future. Despite the increasing trend in mass shootings, they thankfully remain rare events with fewer than 10 mass shootings occurring in a single year. Limited historical data with substantial annual variability poses challenges to accurately forecasting rare events such as the number of mass shootings in the United States. Different forecasting models can be deployed to tackle this challenge. This article compares three forecasting models, a change-point model, a time series model, and a hybrid of a time series model with an artificial neural network model. Each model is applied to forecast the frequency of mass shootings. Comparing among results from these models reveals advantages and disadvantages of each model when forecasting rare events such as mass shootings. The hybrid ARIMA-ANN model can be tuned to follow variation in the data, but the pattern of the variation may not continue into the future. The mean of the change-point model and the ARIMA model exhibit much more less annual variation and are not influenced as much by the inclusion of a single data point. The insights generated from the comparison are beneficial for selecting the best model and accurately estimating the risk of mass shootings in the United States.
Distributed permutation flowshop scheduling problems (DPFSP) have become research hotspots. However, a DPFSP with tardiness and rejection costs (DPTR), which has important practical significance, has ...not yet been addressed. As manufacturers are most concerned about the maximization of the total profit, this study addresses the DPFSP to maximize the total profit. A mixed-integer linear programming model is used to describe the DPTR. An iterated greedy algorithm named IG_TR is proposed. IG_TR generates initial solutions using an improved NEH heuristic using four rules based on the deadline, due date, tardiness and rejection costs. For IG_TR, a dynamic number of jobs are removed from factories in the destruction phase. In the reconstruction phase, the removed jobs and those waiting to be processed are selected to be inserted into appropriate positions in the factories. Two local search methods are designed to improve the quality of solutions generated in the reconstruction phase. During the acceptance phase, a restart mechanism is proposed to avoid falling into local optimal. The experimental results of the component analysis demonstrate the effectiveness of IG_TR. Several comprehensive experiments show that IG_TR outperforms five related algorithms.
Objective
To quantitatively examine the relationship between social support and suicidal ideation (SI) among patients with cancer and identify the moderators that influence the magnitude of this ...association.
Methods
Publications were searched in PubMed, PsycINFO, EMBASE, Cochrane Library and Chinese National Knowledge Infrastructure from database inception to May, 2020. Correlation coefficients (r) were chosen as the effect size with a random model to evaluate the overall effect size between social support and SI in patients with cancer. To assess statistical heterogeneity, we examined potential moderator variables on the social support and SI.
Results
A total of 881 studies were identified in initial search, and twelve studies were eligible. A negative, small but significant correlation (r = −0.22, 95% CIs: −0.30,−0.14, p < 0.001) was observed between social support and SI in patients with cancer, with a significant heterogeneity (I2 = 95.24%, Q = 231.27, p < 0.001). Moderator analyses indicated that race/ethnicity (Q(1) = 8.4, p < 0.05) and measurements of social support (Q(3) = 9.78, p < 0.05) and SI (Q(3) = 9.69, p < 0.05) significantly moderate the effect size between social support and SI.
Conclusion
Taken together, we found a negative yet significant association between social support and SI in patients with cancer, which supported the importance of social support for the prevention of SI in patients with cancer.
In this work, thermally conductive yet electrically insulative polycarbonate (PC)‐based composites with hybrid boron nitride (BN) and flake graphite (Gt) network structure were prepared by high shear ...injection molding process. A synergy in improving the thermal conductivity of PC was observed with the hybrid loading of BN and Gt. Results showed that the in‐plane thermal conductivity of PC/BN 30 wt%/Gt 16 wt% composite reached as high as 4.08 W/mK, which were 189% and 358% higher than that of PC/BN 30 wt% and PC/Gt 16 wt% composites, respectively. The preferred orientation of planar fillers and interconnection between added fillers were indispensable to the significant increase of in‐plane thermal conductivity, as corroborated by X‐ray diffraction, rheology and scanning electron microscope observations. Moreover, the electrical resistivity of PC/BN 30 wt%/Gt composites was higher than 1014 Ω cm, which shows potential application in thermal management areas such as advanced electronic devices and battery units among others.
Acoustic emission (AE) characterization is an effective technique to indirectly capture the failure process of quasi brittle rock. In previous studies, both experiments and numerical simulations were ...adopted to investigate the AE characteristics of rocks. However, as the most popular numerical model, the moment tensor model (MTM) cannot be constrained by the experimental result because there is a gap between MTM and experiments in principle, signal processing and energy analysis. In this paper, we developed a particle-velocity-based model (PVBM) that enabled direct monitoring and analysis of the particle velocity in the numerical model and had good robustness. The PVBM imitated the actual experiment and could fill in gaps between the experiment and MTM. AE experiments of marine shale under uniaxial compression were carried out, and the results were simulated by MTM. In general, the variation trend of the experimental result could be presented by MTM. Nevertheless, the magnitudes of AE parameters by MTM presented notable differences of more than several orders of magnitude compared with those by the experiment. We sequentially used PVBM as a proxy to analyse these discrepancies and systematically evaluate the AE characterization of rocks from the experiment to numerical simulation, considering the influence of wave reflection, energy geometrical diffusion, viscous attenuation, particle size and progressive deterioration of rock material. The combination of MTM and PVBM could reasonably and accurately acquire AE characteristics of the actual AE experiment of rocks by making full use of their respective advantages.
•A parallel-in-time preconditioning technique is proposed for the ill-conditioned and non-symmetric all-at-once system.•The condition number of the preconditioned matrix is proven to be uniformly ...bounded by a constant independent of matrix size.•A fast and exact implementation is proposed for the preconditioned matrix-vector product.
In this paper, we study a parallel-in-time (PinT) algorithm for all-at-once system from a non-local evolutionary equation with weakly singular kernel where the temporal term involves a non-local convolution with a weakly singular kernel and the spatial term is the usual Laplacian operator with variable coefficients. Such a problem has been intensively studied in recent years thanks to the numerous real world applications. However, due to the non-local property of the time evolution, solving the equation in PinT manner is difficult. We propose to use a two-sided preconditioning technique for the all-at-once discretization of the equation. Our preconditioner is constructed by replacing the variable diffusion coefficients with a constant coefficient to obtain a constant-coefficient all-at-once matrix. We split a square root of the constant Laplacian operator out of the constant-coefficient all-at-once matrix as a right preconditioner and take the remaining part as a left preconditioner, which constitutes our two-sided preconditioning. Exploiting the diagonalizability of the constant-Laplacian matrix and the triangular Toeplitz structure of the temporal discretization matrix, we obtain efficient representations of inverses of the right and the left preconditioners, because of which the iterative solution can be fast updated in a PinT manner. Theoretically, the condition number of the two-sided preconditioned matrix is proven to be uniformly bounded by a constant independent of the matrix size. To the best of our knowledge, for the non-local evolutionary equation with variable coefficients, this is the first attempt to develop a PinT preconditioning technique that has fast and exact implementation and that the corresponding preconditioned system has a uniformly bounded condition number. Numerical results are reported to confirm the efficiency of the proposed two-sided preconditioning technique.
Compared with traditional therapies, targeted therapy has merits in selectivity, efficacy, and tolerability. Small molecule inhibitors are one of the primary targeted therapies for cancer. Due to ...their advantages in a wide range of targets, convenient medication, and the ability to penetrate into the central nervous system, many efforts have been devoted to developing more small molecule inhibitors. To date, 88 small molecule inhibitors have been approved by the United States Food and Drug Administration to treat cancers. Despite remarkable progress, small molecule inhibitors in cancer treatment still face many obstacles, such as low response rate, short duration of response, toxicity, biomarkers, and resistance. To better promote the development of small molecule inhibitors targeting cancers, we comprehensively reviewed small molecule inhibitors involved in all the approved agents and pivotal drug candidates in clinical trials arranged by the signaling pathways and the classification of small molecule inhibitors. We discussed lessons learned from the development of these agents, the proper strategies to overcome resistance arising from different mechanisms, and combination therapies concerned with small molecule inhibitors. Through our review, we hoped to provide insights and perspectives for the research and development of small molecule inhibitors in cancer treatment.
Small molecule inhibitors have been permitted to be used in post‐line therapy, first‐line treatment, and adjuvant therapy. Compared with post‐line and first‐line treatment, attempts at adjuvant therapy are just beginning. Several factors should be considered in the adjuvant setting, including other standard treatments, subsequent therapy, financial benefit ratio, and treatment‐related side effects.
Better understanding the evolutionary mechanism of landslides is very important to predict their occurrence based on firm scientific grounds. The stability of a rock slope is often dominated by one ...or more locked segments along a potential slip surface with a large bearing capacity to resist instability. We propose three preliminary categories for locked segments and develop a physical model for predicting the instability of rock slopes with locked segments, by coupling a one-dimensional renormalization group model with a strain-softening constitutive model, based on the Weibull distribution. We found that the ratio of the strain at the peak strength point of a locked segment to the strain at its volume dilation point is exclusively dependent on the Weibull shape parameter m and is approximately constant at 1.48. The accelerating displacement of the slope can be observed from the volume dilation point of the locked segment due to unstable fracture propagation. The physical model for slopes with multiple locked segments is only related to the displacement corresponding to the volume dilation point of the first locked segment and the number of locked segments. Applying this model to two typical cases, the Yanchihe rockslide in China and the wedge rockslide in Libby Dam, USA, the results are in agreement with field records. This work will help to better understand the failure mechanism of slopes with locked segments and may provide guidelines for disaster mitigation and prevention.
•The stability of a rock slope is often dominated by one or more locked segments•Tertiary creep onset corresponds to the volume dilation point of the locked segment•Model is independent of the physical and mechanical parameters of locked segments•The results of two typical case studies support the model
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