Flexible silicone materials have excellent elastic properties and can maintain excellent structural stability under high-intensity repeated deformation. They are ideal materials for preparing ...piezoresistive flexible sensors. However, traditional silicone materials exhibit strong insulation properties. The solid block structure is also not conducive to improving sensitivity. Inspired by the irregular hole structure of Taihu Lake stone, this paper prepared a porous silica gel skeleton (rGO/CTAB/SG) based on reduced graphene oxide film coating, which was equipped with flexible interdigital electrodes to achieve electrical signal derivation. The “honeycomb” shaped sensing module prepared in this way achieves an extremely wide elastic deformation range (20-200%). In the pressure feedback layer, the rGO film is evenly coated on the SG surface, which greatly improves the device conductivity and sensing performance (high sensitivities of 89.4 kPa
− 1
and 25.4 kPa
− 1
are achieved within 0-30.2 kPa and 30.2–42 kPa, ultra-high durability under more than 22,000 load-unload cycles.) Numerical simulation analysis results confirmed that the structure of the flexible substrate SG prepared by this method maintained well when extreme deformation occurred, and no fracture or stress concentration occurred. As an elastic sensor, after being integrated with a microprocessor, it can easily monitor and analyze human body movement in real time. It has huge potential in areas such as daily training and health monitoring of athletes.
In this paper, the speed regulation problem for permanent magnet synchronous motor (PMSM) system under vector control framework is studied. First, a speed regulation scheme based on standard internal ...model control (IMC) method is designed. For the speed loop, a standard internal model controller is first designed based on a first-order model of PMSM by analyzing the relationship between reference quadrature axis current and speed. For the two current loops, PI algorithms are employed respectively. Second, considering the disadvantages that the standard IMC method is sensitive to control input saturation and may lead to poor speed tracking and load disturbance rejection performances, a modified IMC scheme is developed based on a two-port IMC method, where a feedback control term is added to form a composite control structure. Third, considering the case of large variations of load inertia, two adaptive IMC schemes with two different adaptive laws are proposed. A method based on disturbance observer is adopted to identify the inertia of PMSM and its load. Then a linear adaptive law is developed by analyzing the relationship between the internal model and identified inertia. Considering the control input saturation in practical applications, a fuzzy adaptive law based IMC scheme is developed based on apriori experimental tests and experiences, where a fuzzy inferencer based supervisor is designed to automatically tune the parameter of speed controller according to the identified inertia. The effectiveness of the proposed methods have been verified by Matlab simulation and TMS320F2808 DSP experimental results.
Cancer is one of the most devastating diseases, and recently, a variety of natural compounds with preventive effects on cancer developments have been reported. Sulforaphane (SFN) is a potent ...anti-cancer isothiocyanate originating from Brassica oleracea (broccoli). SFN, mainly metabolized via mercapturic acid pathway, has high bioavailability and absorption. The present reviews mainly discussed the metabolism and absorption of SFN and newly discovered mechanistic understanding recent years for SFN's anti-cancer effects including promoting autophagy, inducing epigenetic modifications, suppressing glycolysis and fat metabolism. Moreover, its inhibitory effects on cancer stem cells and synergetic effects with other anti-cancer agents are also reviewed along with the clinical trials in this realm.
Colorectal cancer (CRC) is a global healthcare problem. Radioresistance is a huge setback for CRC radiotherapy. In this text, the roles and molecular mechanisms of long non-coding RNA HOTAIR in CRC ...tumorigenesis and radioresistance were further investigated. ATG12 mRNA, HOTAIR, and microRNA-93 (miR-93) levels were measured by quantitative reverse transcription polymerase chain reaction (RT-qPCR) assay. Protein levels of LC3 I, LC3 II, p62, ATG12, cleaved caspase 3, Bax, and Bcl-2 were detected by western blotting assay in cells and were examined by immunohistochemistry (IHC) assay in tissues. Cell survival fractions, viability, and apoptotic rates were determined by clonogenic survival assay, CCK-8 assay, and flow cytometry analysis, respectively. The relationships of HOTAIR, miR-93, and ATG12 were tested by bioinformatics analysis and luciferase reporter assay. Mouse xenograft tumor models were established to investigate the influence of HOTAIR knockdown on CRC radioresistance in vivo. We found that HOTAIR expression was markedly upregulated in plasma from CRC patients after radiotherapy and CRC cells after irradiation. HOTAIR knockdown, miR-93 overexpression, or ATG12 silencing weakened cell viability, induced cell apoptosis, inhibited cell autophagy, and enhanced cell radiosensitivity in CRC. HOTAIR exerted its functions by downregulating miR-93. Moreover, HOTAIR functioned as a molecular sponge of miR-93 to regulate ATG12 expression. ATG12 protein expression was markedly upregulated and associated with miR-93 and HOTAIR expression in CRC tissues. Furthermore, HOTAIR knockdown enhanced radiosensitivity of CRC xenograft tumors by regulating miR-93/ATG12 axis. In conclusion, HOTAIR knockdown potentiated radiosensitivity through regulating miR-93/ATG12 axis in CRC, further elucidating the roles and molecular basis of HOTAIR in CRC radioresistance.
Breast cancer is a common malignancy with poor prognosis. Cancer cells are heterogeneous and cancer stem cells (CSCs) are primarily responsible for tumor relapse, treatment-resistance and metastasis, ...so for breast cancer stem cells (BCSCs). Diets are known to be associated with carcinogenesis. Food-derived polyphenols are able to attenuate the formation and virulence of BCSCs, implying that these compounds and their analogs might be promising agents for preventing breast cancer. In the present review, we summarized the origin and surface markers of BCSCs and possible mechanisms responsible for the inhibitory effects of polyphenols on BCSCs. The suppressive effects of common dietary polyphenols against BCSCs, such as curcumin, epigallocatechin gallate (EGCG) and related polyphenolic compounds were further discussed.
Background
Circular RNA derived from dipeptidyl peptidase 4 (circDPP4; ID: hsa_circ_0056881) is one of the top increased circRNAs in prostate cancer (PC) and docetaxel (DTX)‐based chemotherapy is the ...primary therapeutic choice for PC. However, its repertoire in PC development and chemoresistance remains to be documented.
Methods
Expression of circDPP4, microRNA (miR)‐564, and zinc finger of the cerebellum 2 (ZIC2) was detected by a real‐time quantitative polymerase chain reaction and western blotting; the direct interaction was validated by an RNA pull‐down assay, a dual‐luciferase reporter assay, and RNA immunoprecipitation. Cell progression was measured by a cell‐counting kit‐8 assay, colony formation assay, flow cytometry, a transwell assay, a xenograft experiment, and immunohistochemistry. DTX cytotoxicity was confirmed by the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) cell viability assay.
Results
Expression of circDPP4 is upregulated in PC tumors from 60 patients and PC cell lines, and a higher circDPP4 might predict poor overall survival. Decreasing circDPP4 suppresses cell proliferation, colony formation, migration/invasion, and 50% inhibitory concentration of DTX in PC cells, and promotes the apoptosis rate. Both overexpressing miR‐564 and inhibiting ZIC2 could imitate those effects, whereas inhibiting miR‐564 and restoring ZIC2 could separately counteract them. Mechanistically, circDPP4 functions as a miR‐564 sponge and regulates the expression of ZIC2, a target gene for miR‐564. Tumor growth is retarded by silencing circDPP4, accompanied by elevated miR‐564 and attenuated Ki‐67 and ZIC2.
Conclusions
Blocking circDPP4 antagonizes cell progression of PC and contributes to in vitro DTX cytotoxicity via regulating the miR‐564/ZIC2 axis, at least. The present study suggests that circDPP4 is a potential biomarker and target for PC.
CircDPP4 sponges miR‐564 from its binding to ZIC2 in PC cells, resulting in excessive proliferation and migration/invasion and decreased apoptosis and DTX cytotoxicity.
Breast cancer stem cell (BCSC) properties are correlated with the malignancy of tumor cells. Sulforaphane (SFN), a natural isothiocyanate, has anti-cancer effects. However, SFN is an oil-like, ...hydrophobic and unstable substance. To enhance the inhibitory effect of SFN on BCSC-like properties, the mineralized hyaluronic acid-SS-tetradecyl nano-carriers (M-HA-SS-TA) were prepared. The nano-carriers possessed high SFN entrapment rate (92.36%) and drug-loading efficiency (33.64%). The carriers were responsive to the high reducing and mild acidic tumor micro-environment, leading to rapid SFN releasing from SFN-loaded nano-drug (SFN/M-HA-SS-TA). Through the specific recognition of breast cancer cells bearing CD44+ by HA, M-HA-SS-TA nano-carriers showed excellent tumor-targeting ability. Moreover, compared with free SFN, SFN/M-HA-SS-TA showed much stronger inhibition on the BCSC-like properties (invasiveness, self-renewal and tumor growth) both in vitro and in vivo. Together, these results suggested M-HA-SS-TA nano-carriers were promising platforms for tumor-targeted delivery of SFN, enhancing the therapeutic efficacy against BCSC-like properties by SFN.
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•Amphipathic hyaluronic acid-SS-tetradecyl conjugates (HA-SS-TA) were synthesized.•Mineralized HA-SS-TA carriers (M-HA-SS-TA) were prepared and could target tumor.•M-HA-SS-TA were responsive to glutathione and low pH in tumor niche.•M-HA-SS-TA improved the anti-breast cancer effect of sulforaphane.
Sperm morphology mainly refers to the shape of the head, the length of the flagellar segments, including the midpiece, principal piece and end piece, and the size of the accessory structures, ...including axonemes, outer dense fibers (ODFs), mitochondrial sheath (MS) and fibrous sheath (FS). Across species, there is considerable diversity in morphology. An established theory posits that the length of the sperm flagellum, especially the length of the midpiece, is a critical factor influencing sperm metabolism and velocity. However, our understanding of the relationships between sperm ultrastructures and the sperm flagellar length is incomplete.
The morphologies of sperm from 10 mammalian species, human, mouse, rat, dog, rabbit, goat, pig, bull, guinea pig and golden hamster, were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). According to the SEM and TME images, the length of sperm heads and flagellar segments, the cross-sectional areas of the accessory structures and flagella and the width of sperm heads were measured using Image J software. The variation tendencies (referred to as slope) of the accessory structures along flagella were calculated by the linear regression method. Mitochondrial functions were measured using commercial kits. The velocities of sperm were measured using CASA software.
The three-dimensional morphologies of sperm from 10 species and the slopes of internal accessory structures along flagella were obtained. The width of the axoneme tapered slightly from the base to the tip of the sperm flagellum, and slopes of the axonemes correlated negatively with the variability in flagellar length across species. Additionally, the cross-sectional areas of the ODFs and/or the MS were positively correlated with the lengths of the midpiece, principal piece, and total flagellum, as well as with sperm velocities. Mitochondrial volumes were positively correlated with ATP content and sperm swimming velocities.
Our results not only show the relationship between sperm internal structures, flagellar length and sperm physiology but also provide sizes of mitochondria and ODFs as new targets with which to study the regulation of sperm length and velocity.
All‐inorganic lead halide perovskites are promising candidates for optoelectronic applications. However, fundamental questions remain over the component interaction in the perovskite precursor ...solution due to the limitation of the most commonly used solvents of N,N‐dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). Here, we report an interaction tailoring strategy for all‐inorganic CsPbI3−xBrx perovskites by involving the ionic liquid solvent methylammonium acetate (MAAc). C=O shows strong interaction with lead (Pb2+) and N−H⋅⋅⋅I hydrogen bond formation is observed. The interactions stabilize the perovskite precursor solution and allow production of the high‐quality perovskite films by retarding the crystallization. Without the necessity for antisolvent treatment, the one‐step air‐processing approach delivers photovoltaic cells regardless of humidity, with a high efficiency of 17.10 % along with long operation stability over 1500 h under continuous light illumination.
By involving a methyl ammonium acetate (MAAc) ionic liquid solvent, strong Pb−O interaction and N−H⋅⋅⋅I hydrogen bonds between MAAc and PbI2 lead to a controllable all‐inorganic perovskite formation in ambient air. The resulting solar cells exhibit high efficiency and excellent stability under continuous light illumination.
Using a nonlinear energy sink to reduce vibration in a broad frequency range has been widely discussed. This paper reports on a study of nonlinear damping of vibration in a system consisting of a ...ring isolator (under harmonic excitation) and a nonlinear energy sink, with the goal of designing a broadband isolator of light weight. A full mathematical model of the ring with the nonlinear energy sink is established, leading to two coupled nonlinear partial differential equations (PDEs) with closed boundary conditions. The PDEs are discretized via the Galerkin method. A harmonic balance analysis is used to derive the frequency response functions of the transmissibility, and the harmonic balance solutions are compared with numerical results using a finite difference method. It is found that the disappearance of a crossed frequency response curve may decrease the transmissibility at the resonances. Also, the quasi-periodic motion can indicate emergence of a knot-shaped crossed resonance curve. The effects of mass, nonlinear stiffness, and damping ratio are examined. With a suitable ring size, the nonlinear energy sink in a ring isolator is superior to a conventional linear absorber of the same mass, damping, and stiffness.
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