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In this paper, we study the hedging effectiveness of crude oil futures on the basis of the lower partial moments (LPMs). An improved kernel density estimation method is proposed to estimate the optimal hedge ratio. We investigate crude oil price hedging by contributing to the literature in the following twofold: First, unlike the existing studies which focus on univariate kernel density method, we use bivariate kernel density to calculate the estimated LPMs, wherein the two bandwidths of the bivariate kernel density are not limited to the same, which is our main innovation point. According to the criterion of minimizing the mean integrated square error, we derive the conditions that the optimal bandwidths satisfy. In the process of derivation, we make a distribution assumption locally in order to simplify calculation, but this type of local distribution assumption is far better than global distribution assumption used in parameter method theoretically and empirically. Second, in order to meet the requirement of bivariate kernel density for independent random variables, we adopt ARCH models to obtain the independent noises with related to the returns of crude oil spot and futures. Genetic algorithm is used to tune the parameters that maximize quasi-likelihood. Empirical results reveal that, at first, the hedging strategy based on the improved kernel density estimation method is of highly efficiency, and then it achieves better performance than the hedging strategy based on the traditional parametric method. We also compare the risk control effectiveness of static hedge ratio vs. time-varying hedge ratio and find that static hedging has a better performance than time-varying hedging. [ABSTRACT FROM AUTHOR]

Cerebellar intermittent theta burst stimulation (iTBS) modulates the excitability of the cerebral cortex and may enhance attentional performance. To date, few studies have conducted iTBS on healthy subjects for one week and used electroencephalography (EEG) to investigate the effect of multiple stimulation sessions on resting-state functional brain networks and the daily stimulation effect on attentional performance. 16 healthy subjects participated in a one-week experiment, receiving bilateral cerebellar iTBS or sham stimulation and engaging in multi-task attentional training. The primary measures were the one-week attentional performance and pre- and post-experiment resting-state EEG activities. Amplitude Envelope Correlation (AEC) was used to construct the functional connectivity in the eye-open (EO) and eye-closed (EC) phases. At least three sessions of iTBS were required to enhance multi-task performance significantly, whereas only one or two sessions failed to elicit the improvement. Compared with the control group, iTBS induced significant changes in PSD, AEC functional connectivity, and AEC network properties during the EO phase, while it had little effect during the EC phase. During the EO phase, the network property changes of the iTBS subject were correlated with improved attentional performance. The multi-task performance requires multiple stimulations to enhance. iTBS affects the resting-state alpha band brain activities during the EO rather than the EC phase. The AEC network properties may serve as a biomarker to assess the attentional potential of healthy subjects. • At least three sessions of iTBS were required to improve multi-task performance. • One-week iTBS has little effect on resting-state brain activity during the EC phase. • For iTBS subjects, more AEC network properties changes lead to better performance. • iTBS causes no adverse effect as functional connectivity are evenly distributed. [ABSTRACT FROM AUTHOR]

The adsorbed and dissolved oil in the shale reservoirs can be produced during CO 2 injection. However, the effects of different factors on the adsorption and dissolution behaviors of CO 2 and oil mixtures in the shale were unclear, such as the oil composition, shale properties and temperature. In this study, a series of adsorption and dissolution tests of CO 2 and different n-alkane mixtures in organic-rich shales were performed under different condition. The effects of the alkane type, shale properties and temperature on the adsorption and dissolution amount of mixtures and the replace ability of CO 2 to n-alkane were discussed, respectively. The results indicate that the dissolution amount was decreased with the chain length of alkane and increased with TOC and temperature. The adsorption amount of the mixtures in shale was low and only account for 3–16% of total adsorption and dissolution amount, which mainly depended on the specific surface area of the shale samples. Additionally, the replace ability of CO 2 to dissolved n-alkane was decreased with the chain length of alkane and temperature. However, there are no obvious rules between the replace ability with TOC of shale. This study can provide useful information for EOR of shale oil reservoirs by CO 2 injection and the geological storage of CO 2 in shale oil reservoir. [ABSTRACT FROM AUTHOR]

• Rheological behaviors of polysaccharides with different substituents have been studied. • Both the saccharide side chain and acetyl substituents improve the gelation of polysaccharide solutions at 25 °C. • The relationship between the apparent viscosity and concentration of GG conforms to the exponential equation. • The stability of gel structure containing longer saccharide side chains shows lower temperature/salt sensitivity. • Deacylated GG solutions transform into hydrogels in the presence of DTAB. Rheological behaviors of microbial polysaccharides with different substituents in aqueous solutions have been systematically investigated. Both the saccharide side chains and acetyl substituents improve the gelation of welan gum (WG), diutan gum (DG) and gellan gum (GG) in pure water at 25 °C. For the polysaccharides with saccharide side chains (WG and DG), the relationship between the apparent viscosity and concentration conforms to the linear equation, while that of the polysaccharide with acetyl (GG) is exponential. More importantly, the roles of substituents on the stability of the molecular conformation of polysaccharides are significantly depended on the surrounding environment. Disaccharide side chains promote the stability of helical conformation and gel aggregates of GG at high temperature (85 °C) or in the presence of inorganic salts with the ionic strength of 2.0 mol L−1. The stability of gel structure containing acetyl (GG) shows higher temperature/salt sensitivity. Additionally, deacylated gellan gum (GG(d)) solutions transform into hydrogels in the presence of dodecyltrimethylammonium bromide (DTAB). This study will help to obtain a better understanding on the rheological properties of polysaccharides with respect to the conformation and applications. [ABSTRACT FROM AUTHOR]

As natural adjuvants, the bacterial outer membrane vesicles (OMV) hold great potential in cancer vaccines. However, the inherent immunotoxicity of OMV and the rarity of tumor-specific antigens seriously hamper the clinical translation of OMV-based cancer vaccines. Herein, metal-phenolic networks (MPNs) are used to attenuate the toxicity of OMV, meanwhile, provide tumor antigens via the chemodynamic effect induced immunogenic cell death (ICD). Specifically, MPNs are assembled on the OMV surface through the coordination reaction between ferric ions and tannic acid. The iron-based "prison" is locally collapsed in the tumor microenvironment (TME) with both low pH and high ATP features, and thus the systemic toxicity of OMV is significantly attenuated. The released ferric ions in TME promote the ICD of cancer cells through Fenton reaction and then the generation of abundant tumor antigens, which can be used to fabricate in-situ vaccines by converging with OMV. Together with the immunomodulatory effect of OMV, potent tumor repression on a bilateral tumor model is achieved with good biosafety. • Metal-phenolic network is first used for not only attenuating the toxicity of OMV but also fabricating in situ vaccines. • The smart synergism of in situ vaccines with TME reprogramming leads to robust tumor repression and immunological memory. • This convenient and reliable engineering strategy can be popularized in the construction of different bioactive formulations. [ABSTRACT FROM AUTHOR]

• Effects of polyether surfactants on improving oil–CO 2 miscibility are investigated. • Miscible degree parameter is defined to assess oil–CO 2 miscibility in MD simulation. • PO chain length of polyether exerts huge impacts on improving oil–CO 2 miscibility. • Micro-mechanism of polyether surfactant promoting oil–CO 2 miscibility is proposed. Accomplishing the high miscibility of CO 2 and crude oil under reservoir conditions is critical for achieving the most efficient recovery process by CO 2 injection into low-porosity and low-permeability reservoirs. In this study, the effects of nonionic polyether surfactants on improving the miscibility of CO 2 –hydrocarbon systems were investigated. The influence of polyether structure on the reduction of miscibility pressure between CO 2 and hydrocarbons was evaluated by experiments. The results showed that the miscibility pressure of CO 2 and C 16 could be reduced by 4.8% to 10.2% after adding 0.04 mol polyethers with different structures per kg CO 2. The capability of polyethers to improve oil–gas miscibility exhibited a first growing then diminishing trend with increasing polyoxypropylene chain length and decreased with increasing alkyl chain length. Moreover, the microscopic influence mechanism of polyether on the miscible processes of CO 2 –hydrocarbon systems was investigated by molecular dynamics simulations. The miscible degree parameter was defined in the simulation to quantitatively estimate oil–gas miscibility. The distributions of different molecules and potential interactions during the miscible process were analyzed. The simulation results showed that the solubilization of CO 2 molecules among polyoxypropylene chains in the oil phase caused by the local aggregation of nonionic polyether surfactants enhanced the vdW interactions between hydrocarbons and CO 2 and then improved the oil–gas miscibility. Furthermore, simulation results suggested that the number of polyoxypropylene groups in the nonionic polyether surfactant should be maintained at 8 to achieve the highest amount of CO 2 solubilization and the best potential in improving the oil–gas miscibility. The study results provide guidance for understanding the miscible behavior among CO 2 , additives, and hydrocarbons, as well as designing the appropriate additive structures for improving oil–gas miscibility. [ABSTRACT FROM AUTHOR]

• A quantitative evaluation method of additive promoting miscibility was proposed. • Polyoxypropylene alkyl ethers significantly improved oil–gas miscibility. • Low molecular weight surfactants with high PO groups exhibited the best effect. • Solubilization of CO 2 in oil resulted in a reduction of miscibility pressures. Certain unique reservoir conditions and technical difficulties have greatly limited the use of CO 2 miscible injection in unconventional reservoirs. Lowering the miscibility pressure to realize the miscibility of CO 2 and crude oil is critical for achieving the most efficient recovery process. In this study, we investigated whether nonionic polyether surfactants could improve the miscibility of CO 2 and hydrocarbons. And an improved experimental method for a quantitative evaluation of additive efficiencies in lowering the miscibility pressure was introduced for the first time. The dissolution behaviors of nonionic polyether surfactants in CO 2 and phase behaviors of CO 2 –hydrocarbon systems with and without surfactant additives were conducted. The effects of surfactant structure and concentration and temperature on the solubility of nonionic polyether surfactants in CO 2 along with the efficiency of miscibility pressure reduction for CO 2 –hydrocarbon systems were analyzed. The results showed that the polyoxypropylene alkyl ethers exhibited excellent potential for improving the miscibility of the CO 2 and hydrocarbons, especially when low molecular weight surfactant molecules with high polyoxypropylene group content were used. The first-contact miscibility pressure (FCMP) of the mixed oil and CO 2 could be reduced by as much as 22.51% with 3 wt% C 4 (PO) 3 addition. Furthermore, a mechanistic understanding showed that the solubilization of the CO 2 caused by polyether reverse micelles resulted in a reduction of miscibility pressures for CO 2 –hydrocarbon systems. The study results and the novel evaluation method provided guidance for designing and selecting appropriate additive structures to reduce miscibility pressures of CO 2 –oil systems and meet the CO 2 miscible injection technology requirements. [ABSTRACT FROM AUTHOR]

Abstract: Self-assembled three-dimensional (3D) hierarchical Bi2WO6 microspheres built from 2D nanoplates alignment were successfully prepared by the sol–gel–hydrothermal route. Based on X-ray diffraction and scanning electron microscopy observation of the products at different reaction time periods, the formation mechanism of 3D hierarchical Bi2WO6 microspheres was proposed. UV–vis diffuse reflectance spectra indicated that the obtained 3D hierarchical Bi2WO6 microspheres had enhanced absorption in both UV and visible light regions. The photocatalytic activities of the as-prepared products were evaluated by monitoring the degradation of methylene blue solution under visible light irradiation. Due to the structural feature and good optical quality, Bi2WO6 prepared by the sol–gel–hydrothermal route possessed the highest photocatalytic activity than those of Bi2WO6 samples prepared by hydrothermal and sol–gel routes. [Copyright &y& Elsevier]

Nitrobenzoxadiazole (NBD)-incorporated naphthalene diimide derivatives were designed and synthesized as candidates of antitumor agents with cytotoxicity against human pancreatic cancer cell MIA PaCa-2. Among these, compounds 1NND and 3NND exhibited fluorescent "turn-off" property toward human telomeric G-quadruplex (G4), which allows the direct measurement of dissociation constant (K d ) of ligands against G4 by fluorescence titration method. Notably, the compound 1NND not only exhibited great cytotoxic activity against MIA PaCa-2 with a half maximal inhibitory concentration (IC 50 ) of 77.9 nM, but also exhibited high affinity against G4 with K d of 1.72 μM. Furthermore, the target binding properties were investigated by circular dichroism (CD) spectra and further studied by molecular docking methods., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

A 24-year-old male patient complained of mild knee pain after jogging. The subsequent knee MRI demonstrated bilateral lateral thickened tibiofemoral cartilages, evidenced by deformities of the bilateral subchondral bone beneath the lateral femoral condyle cartilage. The corresponding dislocations of almost all the left lateral meniscus and part of the right lateral meniscus to the center of the joint were detected. After excluding diagnoses of congenital ring-shaped meniscus, bucket handle tear of the C-shaped lateral meniscus, and central tear of the discoid meniscus, the displacement of all or part of the lateral meniscus into the intercondylar notch was considered a consequence of congenital thickening of the lateral superior and inferior cartilage. This case may report a new variant of knee joint pathology., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Zhang, Li, Li, Xie, Zhu, Lei and Zhang.)

Lithium cobalt oxide (LCO) has been widely used as a leading cathode material for lithium-ion batteries in consumer electronics. However, unstable cathode electrolyte interphase (CEI) and undesired phase transitions during fast Li + diffusivity always incur an inferior stability of the high-voltage LCO (HV-LCO). Here, an ultra-thin amorphous titanium dioxide (TiO 2 ) coating layer engineered on LCO by an atomic layer deposition (ALD) strategy is demonstrated to improve the high-rate and long-cycling properties of the HV-LCO cathode. Benefitting from the uniform TiO 2 protective layer, the Li + storage properties of the modified LCO obtained after 50 ALD cycles (LCO-ALD50) are significantly improved. The results show that the average Li + diffusion coefficient is nearly tripled with a high-rate capability of 125 mAh g -1 at 5C. An improved cycling stability with a high-capacity retention (86.7%) after 300 cycles at 1C is also achieved, far outperforming the bare LCO (37.9%). The in situ XRD and ex situ XPS results demonstrate that the dense and stable CEI induced by the surface TiO 2 coating layer buffers heterogenous lithium flux insertion during cycling and prevents electrolyte, which contributes to the excellent cycling stability of LCO-ALD50. This work reveals the mechanism of surface protection by transition metal oxides coating and facilitates the development of long-life HV-LCO electrodes.

Nanodelivery systems (NDSs) provide promising prospects for decreasing drug doses, reducing side effects, and improving therapeutic effects. However, the bioapplications of NDSs are still compromised by their fast clearance, indiscriminate biodistribution, and limited tumor accumulation. Hence, engineering modification of NDSs aiming at promoting tumor-specific therapy and avoiding systemic toxicity is usually needed. An NDS integrating various functionalities, including flexible camouflage, specific biorecognition, and sensitive stimuli-responsiveness, into one sequence would be "smart" and highly effective. Herein, we systematically summarize the related principles, methods, and progress. At the end of the review, we predict the obstacles to precise nanoengineering and prospects for the future application of NDSs., (© 2024 Wiley-VCH GmbH.)

Background: In addition to evaluate the morphologic characteristics of intracranial aneurysms, the dimension of the aneurysm is an important parameter for selecting treatment strategies, determining follow-up period, and predicting the risk of rupture. High-resolution vessel wall imaging has an increasingly dominant role in measuring aneurysm size and assessing the risk of rupture accurately. The size of saccular intracranial aneurysm may play an important role as a predictor of the rupture risk. With the rapid improvement in radiological techniques, different noninvasive imaging methods have respective characteristics in saccular intracranial aneurysms (sIA) measurement and morphologic description. Although most studies believe that the larger the aneurysm, the higher the risk of rupture, there is still a synergistic effect of multiple factors (such as location, morphology, history of aneurysmal subarachnoid hemorrhage, and even patient factors) to explain the rupture of small aneurysms., Methods: A literature search was performed of intracranial aneurysm size and risk of rupture., Results: The specificity and sensitivity of different imaging methods for evaluating intracranial aneurysms varied based on sizes. Rupture risk of aneurysms was associated with multiple factors. A comprehensive assessment that considered aneurysm size in conjunction with other relevant factors would be helpful in guiding options of management., Conclusions: Accurate measurement of the dimension of sIA is an important basis in the selection of appropriate treatment including intravascular intervention or surgical clipping, as well as for determining the follow-up cycles for conservative or postoperative treatment. A uniform definition of sIA size is recommended to facilitate the integration of similar studies and to accomplish rapid and effective screening of cases in sIA treatment., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)