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1.
Front Nutr ; 11: 1421560, 2024.
Article in English | MEDLINE | ID: mdl-39010859

ABSTRACT

Objective: Handgrip strength (HGS) and the high-sensitivity modified Glasgow prognostic score (HS-mGPS) are associated with the survival of patients with cancer. However, no studies have investigated the combined effect of HGS and HS-mGPS on the overall survival (OS) of patients with colon cancer. Methods: Prospective follow-up data of colon cancer patients undergoing radical resection from April, 2016 to September, 2019 were retrospectively collected. We combined the HGS and HS-mGPS to create a new composite index, HGS-HS-mGPS. The hazard ratio (HR) and 95% confidence interval (CI) were calculated using Cox regression models to assess the association between variables and OS. Risk factors on OS rates were investigated by Cox analyses and the nomogram was constructed using significant predictors and HGS-HS-mGPS. The predictive performance of the nomogram was evaluated by receiver operating characteristic curve and calibration curve. Results: This study included a total of 811 patients, of which 446 (55.0%) were male. The HGS optimal cut-off values of male and female patients were 28.8 and 19.72 kg, respectively. Multivariate analysis revealed that low HGS and high HS-mGPS were independent risk factors of colon cancer after adjusting confounders (adjusted HR = 3.20; 95% CI: 2.27-4.50; p < 0.001 and adjusted HR = 1.55; 95% CI: 1.12-2.14; p = 0.008 respectively). Patients with low HGS and high HS-mGPS had a 10.76-fold higher mortality risk than those with neither (adjusted HR = 10.76; 95% CI: 5.38-21.54; p < 0.001). A nomogram predicting 1-, 3-, and 5 year OS was constructed based on three clinicopathologic prognostic factors. Importantly, incorporating HGS-HS-mGPS into the nomogram model meaningfully improved the predictive performance. The decision curve analyses demonstrated the application value of the HGS-HS-mGPS nomogram for predicting OS of patients with colon cancer. Conclusion: HGS-HS-mGPS is associated with the survival of patients with colon cancer. These findings indicate the usefulness of HGS and HS-mGPS measurements in clinical practice for improving patient assessment, cancer prognosis, and precise intervention.

2.
Environ Geochem Health ; 46(2): 45, 2024 Jan 16.
Article in English | MEDLINE | ID: mdl-38227264

ABSTRACT

In order to study the influence of water-rock interaction on the mass time-varying characteristics of coal rocks, coal was selected as the research object and subjected to chemical immersion tests with different pH aqueous solutions for 12 days. By experiment, the time-varying patterns of mass change fraction in coal samples, pH value in solution, and ions concentration of calcium and magnesium were obtained. Based on the gray correlation theory, the correlation degree between the mass change fraction and four influencing factors was analyzed. The gray prediction models for the mass time-varying characteristics of coal rocks have been established. The research shows that: (1) the influence ways and degree of different pH aqueous solutions on the mass changes of coal rocks are different, (2) during the process of water-rock interaction, the change law of pH value, ions concentration of calcium and magnesium in solution are obvious, (3) the multiple regression models can be used to predict the mass change of coal rocks accurately under water-rock interaction.


Subject(s)
Calcium , Magnesium , Coal , Water
4.
Adv Mater ; 36(16): e2311992, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38183353

ABSTRACT

Advances in modern industrial technology continue to place stricter demands on engineering polymeric materials, but simultaneously possessing superior strength and toughness remains a daunting challenge. Herein, a pioneering flexible cage-reinforced supramolecular elastomer (CSE) is reported that exhibits superb robustness, tear resistance, anti-fatigue, and shape memory properties, achieved by innovatively introducing organic imide cages (OICs) into supramolecular networks. Intriguingly, extremely small amounts of OICs make the elastomer stronger, significantly improving mechanical strength (85.0 MPa; ≈10-fold increase) and toughness (418.4 MJ m-3; ≈7-fold increase). Significantly, the cooperative effect of gradient hydrogen bonds and OICs is experimentally and theoretically demonstrated as flexible nodes, enabling more robust supramolecular networks. In short, the proposed strengthening strategy of adding flexible cages effectively balances the inherent conflict between material strength and toughness, and the prepared CSEs are anticipated to be served in large-scale devices such as TBMs in the future.

5.
Nat Commun ; 14(1): 4712, 2023 Aug 05.
Article in English | MEDLINE | ID: mdl-37543695

ABSTRACT

Self-healing and recyclable polymer materials are being developed through extensive investigations on noncovalent bond interactions. However, they typically exhibit inferior mechanical properties. Therefore, the present study is aimed at synthesizing a polyurethane-urea elastomer with excellent mechanical properties and shape-memory-assisted self-healing behavior. In particular, the introduction of coordination and hydrogen bonds into elastomer leads to the optimal elastomer exhibiting good mechanical properties (strength, 76.37 MPa; elongation at break, 839.10%; toughness, 308.63 MJ m-3) owing to the phased energy dissipation mechanism involving various supramolecular interactions. The elastomer also demonstrates shape-memory properties, whereby the shape recovery force that brings damaged surfaces closer and facilitates self-healing. Surprisingly, all specimens exhibite clustering-triggered emission, with cyan fluorescence is observed under ultraviolet light. The strategy reported herein for developing multifunctional materials with good mechanical properties can be leveraged to yield stimulus-responsive polymers and smart seals.

6.
ACS Appl Mater Interfaces ; 15(35): 41937-41949, 2023 Sep 06.
Article in English | MEDLINE | ID: mdl-37605560

ABSTRACT

Developing high-performance elastomers with distinctive features opens up new vistas and exciting possibilities for information encryption but remains a daunting challenge. To surmount this difficulty, an unprecedented synthetic approach, "modular molecular engineering", was proposed to develop tailor-made advanced elastomers. The customized hydrophobic poly(urea-urethane) (HPUU-R) elastomer perfectly integrated ultrahigh tensile strength (∼75.3 MPa), extraordinary toughness (∼292.5 MJ m-3), satisfactory room-temperature healing, high transparency, puncture-, scratch-, and water-resistance; and miraculously, its 0.20 g film could lift objects over 100 000 times its weight without rupture. Intriguingly, we unexpectedly discovered that the elastomers fluoresce brightly at the optimal excitation wavelength attributed to the "clusterization-triggered emission". Based on the gradient hydrophobicity and fluorescent properties of HPUU-R, a hierarchical information encryption/decryption mode was innovatively established. Using high-performance HPUU-R as a double encryption platform makes the information highly stable and persistent, thus providing a stronger guarantee for the encrypted information. More attractively, given the impressive recyclability and self-healing of HPUU-R, information encryption can be realized by using recycled elastomers, injecting new vitality into green and sustainable development.

7.
J Chem Phys ; 159(3)2023 Jul 21.
Article in English | MEDLINE | ID: mdl-37477215

ABSTRACT

Neutron and γ-ray irradiation damages to transistors are found to be non-additive, and this is denoted as the irradiation synergistic effect (ISE). Its mechanism is not well-understood. The recent defect-based model [Song and Wei, ACS Appl. Electron. Mater. 2, 3783 (2020)] for silicon bipolar junction transistors (BJTs) achieves quantitative agreement with experiments, but its assumptions on the defect reactions are unverified. Going beyond the model requires directly representing the effect of γ-ray irradiation in first-principles calculations, which was not feasible previously. In this work, we examine the defect-based model of the ISE by developing a multiscale method for the simulation of the γ-ray irradiation, where the γ-ray-induced electronic excitations are treated explicitly in excited-state first-principles calculations. We find the calculations agree with experiments, and the effect of the γ-ray-induced excitation is significantly different from the effects of defect charge state and temperature. We propose a diffusion-based qualitative explanation of the mechanism of positive/negative ISE in NPN/PNP BJTs in the end.

8.
ACS Appl Mater Interfaces ; 15(20): 24968-24977, 2023 May 24.
Article in English | MEDLINE | ID: mdl-37165632

ABSTRACT

Shape memory polymer (SMP)-based smart molds, which could provide high-resolution mold shape and morph in response to external stimuli for readily demolding the complex structure, attract extensive attention. However, the suitable SMP for smart molds is usually confined with low stretchability that likely causes damage during demolding. Herein, we present a cyanate ester smart composite (CESC) with a reconfigurable, solvent-processable, and near-infrared (NIR)-triggerable shape memory effect (SME), which enables the 2D sheet with a variety of morphed complex shapes through deformation in a mild situation. Notably, the reconfigurable SME and the recyclability of the shape memory cyanate ester (SMCE) were addressed for the first time, attributed to the dynamic covalent bonds of transesterification and the novel cyanurate exchange. In addition, we found that the mechanism of solvent-processable SME is attributed to the varied cross-linking density and the mobility of the polymer chain. Integrating the multiple responsive SME and reconfigurable SME, the CESC demonstrated versatile applications as a smart mold. The results demonstrate a wide scope of application of the integrated SME and provide a new design strategy for thermoset cyanate materials.

9.
Adv Mater ; 34(45): e2205763, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36103729

ABSTRACT

To address the challenge of realizing multifunctional polymers simultaneously exhibiting high strength and high toughness through molecular engineering, ultrastrong and supertough shape-memory poly(urea-urethane) (PUU) is fabricated by regulating: i) the reversible cross-links composed of rigid units and multiple hydrogen bonds, and ii) the molecular weight of soft segments. The optimal material exhibits an unparalleled strength of 84.2 MPa at a large elongation at a break of 925.6%, a superior toughness of 322.8 MJ m-3 , and remarkable fatigue resistance without fracture. The repeated stretching of this material induces an irreversible deformation, which, however, can be rapidly recovered by heating. Moreover, all samples are capable of temporary shape fixation at -40 °C (recovering the original shape at 30 °C) and exhibit blue fluorescence when excited at the optimum wavelength, which is ascribed to clusterization-triggered emission (CTE) due to the formation of microphase-separation structures. Thus, the adopted approach provides a solution to a long-standing problem and paves the way to the realization of intrinsically luminescent shape-memory materials exhibiting both ultrahigh strength and ultrahigh toughness.

10.
Polymers (Basel) ; 14(13)2022 Jun 22.
Article in English | MEDLINE | ID: mdl-35808583

ABSTRACT

Wave-absorbing materials are developing in the direction of "light weight, wide frequency band, thin layer and high strength", and it is difficult to achieve the synergy between wave-absorbing performance and mechanical properties when graphene absorbent is compounded with a single resin matrix. In this paper, based on the preparation of a new composite absorbing wire with a graphene (GR)/spherical graphite (SG) double absorbent and polylactic acid (PLA)/thermoplastic polyurethane (TPU) double matrix, we proposed a new method to prepare samples for testing the electromagnetic parameters and tensile strength by fused deposition modeling (FDM). Furthermore, the effect of SG/GR ratio on the microwave absorbing properties and mechanical properties of PLA/TPU composites was specifically studied. It was found that when the ratio of SG/GR was small (0:5, 1:4), the dielectric loss (interfacial polarization loss, dipole polarization loss, conductivity loss) and attenuation ability of the composites were stronger, and the impedance matching was better. When the SG/GR ratio was large (5:0, 4:1), the composites had high strength and toughness. When the ratio of SG/GR was moderate (2:3, 3:2), it could retain the absorbing and mechanical properties of the absorbing materials. On the one hand, the SG and PLA/TPU matrix formed an "island structure", which improves the dispersion of GR; on the other hand, the GR and PLA/TPU matrix formed a "core-shell structure", which promotes polarization and multiple scattering.

11.
Phys Chem Chem Phys ; 23(5): 3417-3428, 2021 Feb 07.
Article in English | MEDLINE | ID: mdl-33506833

ABSTRACT

Solids undergo displacement damage (DD) when interacting with energetic particles, which may happen during the fabrication of semiconductor devices, in harsh environments and in certain analysis techniques. Simulations of DD generation are usually carried out using classical molecular dynamics (MD), but classical MD does not account for all the effects in DD, as demonstrated by ab initio calculations of model systems in the literature. A complete ab initio simulation of DD generation is impractical due to the large number of atoms involved. In my previous paper [Yang, Phys. Chem. Chem. Phys., 2020, 22, 19307], I developed an adaptive-center (AC) method for the adaptive-partitioning (AP) of quantum mechanics/molecular mechanics (QM/MM) simulations, allowing the active region centers and the QM/MM partition to be determined on-the-fly for energy-conserving AP-QM/MM methods. I demonstrated that the AC-AP-QM/MM is applicable to the simulation of DD generation, so that the active regions can be treated using an ab initio method. The AC method could not be used to identify the fast-moving recoil ions in DD generation as active region centers, however, and the accuracy is negatively affected by the rapid change in the QM/MM partition of the system. In this paper, I extend the AC method and develop a speed-dependent adaptive-center (SDAC) method for accurate AP-QM/MM simulations of DD. The SDAC method is applicable to general problems with speed-dependent active regions, and is compatible with all existing energy-conserving partitioning-by-distance AP-QM/MM methods. The artifact due to the speed-dependent potential energy surface can be made small by choosing suitable criteria. I demonstrate the SDAC method by simulations of DD generation in bulk silicon.

12.
Clin Lab ; 67(1)2021 Jan 01.
Article in English | MEDLINE | ID: mdl-33491425

ABSTRACT

BACKGROUND: miRNAs have been proved to function as diagnostic biomarkers. Extracellular vesicles (EVs) are carriers of miRNAs. This study aimed to investigate the diagnostic potential of miR-1 in plasma and extracellular vesicles (EVs) for patients with colorectal cancer (CRC). METHODS: Bioinformatics analysis was used to find a target miRNA and its potential functions. miR-1 was then detected in plasma and EV from 49 control samples and 40 CRC samples. Next, the diagnostic potential of plasma and EV miR-1 were compared based on common biomarkers including CEA and CA211. RESULTS: miR-1 was differentially expressed in CRC. Target gene and function analyses showed that it might participate in cell migration and the regulation of mRNA splicing via the spliceosome. Plasma miR-1 levels in CRC samples were significantly higher than those in control samples, whereas EV miR-1 levels were not statistically different. Based on receiver operating characteristic (ROC) curve analysis, comparing their predictive power compared to that of CEA and CA211, plasma miR-1 performed better and EV miR-1 performed worse. CONCLUSIONS: Our data indicate that plasma miR-1, but not EV miR-1, could function as a potential biomarker for CRC diagnosis.


Subject(s)
Colorectal Neoplasms , Extracellular Vesicles , MicroRNAs , Biomarkers, Tumor/genetics , Colorectal Neoplasms/diagnosis , Colorectal Neoplasms/genetics , Humans , MicroRNAs/genetics , ROC Curve
13.
Phys Chem Chem Phys ; 22(34): 19307-19317, 2020 Sep 08.
Article in English | MEDLINE | ID: mdl-32820763

ABSTRACT

Quantum mechanics/molecular mechanics (QM/MM) methods are widely used in molecular dynamics (MD) simulations of large systems. By partitioning the system into active and environmental regions and treating them with different levels of theory, QM/MM methods achieve accuracy and efficiency at the same time. Adaptive-partitioning (AP) QM/MM allows the partition of the system to change during the MD simulation, making it possible to simulate processes in which the active and environmental regions exchange atoms or molecules, such as processes in solutions or solids. AP-QM/MM methods usually partition the system according to distances to centers of active regions. For energy-conserving AP-QM/MM methods, these centers are chosen beforehand and remain fixed during the MD simulation, making it difficult to simulate processes in which active regions may occur or vanish. In this paper, I develop an adaptive-center (AC) method that allows on-the-fly determination of the centers of active regions according to any geometrical criterion or any criterion dependent on the potential energy. The AC method is compatible with all existing energy-conserving AP-QM/MM methods, and the resulting potential energy surface is smooth. The application of the AC method is demonstrated with two examples in solid systems.

14.
Phys Chem Chem Phys ; 22(32): 17987-17998, 2020 Aug 24.
Article in English | MEDLINE | ID: mdl-32749442

ABSTRACT

Quantum mechanics/molecular mechanics (QM/MM) is the method of choice for atomistic simulations of large systems that can be partitioned into active and environmental regions. Adaptive-partitioning (AP) methods extend the applicability of QM/MM, allowing active regions to change during the simulation. AP methods achieve continuous potential energy surface (PES) by introducing buffer regions in which atoms have both QM and MM characters. Most of the existing AP-QM/MM methods require multiple QM calculations per time step, which can be expensive for systems with many atoms in buffer regions. Although one can lower the computational cost by grouping atoms into fragments, this may not be possible for all systems, especially for applications in covalent solids. The SISPA method [Field, J. Chem. Theory Comput., 2017, 13, 2342] differs from other AP-QM/MM methods by only requiring one QM calculation per time step, but it has the flaw that the QM charge density and wavefunction near the buffer/MM boundary tend to those of isolated atoms/fragments. Besides, regular QM/MM methods for treating covalent bonds cut by the QM/MM boundary are incompatible with SISPA. Due to these flaws, SISPA in its original form cannot treat covalently bonded systems properly. In this work, I show that a simple modification to the SISPA method improves the treatment of covalently bonded systems. I also study the effect of correcting the charge density in SISPA by developing a density-corrected pre-scaled algorithm. I demonstrate the methods with simple molecules and bulk solids.

15.
ACS Appl Mater Interfaces ; 10(48): 41699-41706, 2018 Dec 05.
Article in English | MEDLINE | ID: mdl-30406993

ABSTRACT

Despite recent advances in the stimuli-responsive composites for oil storage and smart lubrication, achieving the high oil storage and recyclable smart-lubrication remains a challenge. Herein, a novel cobweb-like structural system consisting of oil warehouse and transportation system was designed and prepared and it shows high capacity of oil storage and recyclable smart-lubrication. Hollow SiO2 microspheres grated of KH550 and porous polyimide (PPI) were used as oil warehouse and pipeline, respectively, to build the smart system. Because of the novel structure, the composites can keep both high oil-content and oil-retention. Applying stimuli on materials resulted in lubricants releasing on the contact surface which can reduce the friction and wear during sliding. However, removing stimuli, the capillary force induced the sucking back of lubricant into the interior of composites through interconnected small pores of PPI. On the basis of high oil storage and stimuli-responsive performance, the composites can be used for recyclable smart-lubrication. The composites showed remarkable lubricating properties (coefficient of friction 0.056 and Ws 3.55 × 10-7 mm3 N-1 m-1) when the content of KHSM (hollow silica microspheres grated of KH550 (3-Aminopropyltriethoxysilane)) was 1.5 wt % by subjecting it to macroscopic pin-on-disc friction tests. Therefore, cobweb-like structural composites with oil warehouse and transportation system hold the promise for formulating of high oil storage and recyclable smart-lubrication.

16.
Phys Rev Lett ; 119(3): 033003, 2017 Jul 21.
Article in English | MEDLINE | ID: mdl-28777595

ABSTRACT

A very specific ensemble of ground and excited states is shown to yield an exact formula for any excitation energy as a simple correction to the energy difference between orbitals of the Kohn-Sham ground state. This alternative scheme avoids either the need to calculate many unoccupied levels as in time-dependent density functional theory (TDDFT) or the need for many self-consistent ensemble calculations. The symmetry-eigenstate Hartree-exchange (SEHX) approximation yields results comparable to standard TDDFT for atoms. With this formalism, SEHX yields approximate double excitations, which are missed by adiabatic TDDFT.

17.
Proc Natl Acad Sci U S A ; 114(11): 2801-2806, 2017 03 14.
Article in English | MEDLINE | ID: mdl-28265085

ABSTRACT

The fundamental energy gap of a periodic solid distinguishes insulators from metals and characterizes low-energy single-electron excitations. However, the gap in the band structure of the exact multiplicative Kohn-Sham (KS) potential substantially underestimates the fundamental gap, a major limitation of KS density-functional theory. Here, we give a simple proof of a theorem: In generalized KS theory (GKS), the band gap of an extended system equals the fundamental gap for the approximate functional if the GKS potential operator is continuous and the density change is delocalized when an electron or hole is added. Our theorem explains how GKS band gaps from metageneralized gradient approximations (meta-GGAs) and hybrid functionals can be more realistic than those from GGAs or even from the exact KS potential. The theorem also follows from earlier work. The band edges in the GKS one-electron spectrum are also related to measurable energies. A linear chain of hydrogen molecules, solid aluminum arsenide, and solid argon provide numerical illustrations.

18.
Nat Chem ; 8(9): 831-6, 2016 09.
Article in English | MEDLINE | ID: mdl-27554409

ABSTRACT

One atom or molecule binds to another through various types of bond, the strengths of which range from several meV to several eV. Although some computational methods can provide accurate descriptions of all bond types, those methods are not efficient enough for many studies (for example, large systems, ab initio molecular dynamics and high-throughput searches for functional materials). Here, we show that the recently developed non-empirical strongly constrained and appropriately normed (SCAN) meta-generalized gradient approximation (meta-GGA) within the density functional theory framework predicts accurate geometries and energies of diversely bonded molecules and materials (including covalent, metallic, ionic, hydrogen and van der Waals bonds). This represents a significant improvement at comparable efficiency over its predecessors, the GGAs that currently dominate materials computation. Often, SCAN matches or improves on the accuracy of a computationally expensive hybrid functional, at almost-GGA cost. SCAN is therefore expected to have a broad impact on chemistry and materials science.

19.
ACS Appl Mater Interfaces ; 8(33): 21691-9, 2016 Aug 24.
Article in English | MEDLINE | ID: mdl-27463202

ABSTRACT

Conventional thermoset shape memory polymers can maintain a stable permanent shape, but the intrinsically chemical cross-linking leads to shape that cannot be altered. In this paper, we prepared shape memory graphene-vitrimer composites whose shape can be randomly changed via dynamic covalent transesterification reaction. Consecutive shape memory cycles indicate stable shape memory with undetected strain shift and constant shape fixity and recovery values (Rf > 99%, Rr > 98%). Quantitative characterization of shape reconfiguration by dynamic mechanical thermal analysis (DMA) shows prime reconfigurable behavior with shape retention ratio of 100%. Thus, the arbitrary 2D or 3D newly permanent shape can be easily obtained from a simple plain sample by facile thermal treatment at 200 °C above transesterification temperature (Tv). Besides, it is found that graphene-vitrimers show a ductile fracture in tensile test with a large breaking strain and classical yield phenomenon because of the well-dispersed graphene sheets in the vitrimer that endow effective stress transfer. As the graphene loading increases from 0% to 1%, the yield strength and breaking stain increase from 12.0 MPa and 6% to 22.9 MPa and 44%, respectively. In addition, graphene also serves as energy convertor to convert near-infrared (NIR) irradiation into thermal energy to induce a helix shape sample that is recovered totally within 80 s sequent NIR irradiation. These dual-triggered and reconfigurable shape memory graphene-vitrimers are expected to significantly simplify processing of complex shape and broaden the applications of shape memory polymers.

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