M-integral analysis for cracks in a viscoplastic material with extended finite element method

The M-integral can be used to quantify complex damage in materials subjected to mechanical deformation. However, the effect of viscoplasticity on the damage level associated with the M-integral has not been studied yet. In this paper, the variation of the M-integral associated with viscoplastic deformation was investigated numerically using a user-defined material subroutine. Effects of creep deformation and loading rate on the M-integral were also evaluated. In particular, the association of crack growth with the evolution of the M-integral was captured by the extended finite element method for different crack configurations. It was found that viscoplastic deformation has a great effect on the damage evolution of viscoplastic materials characterized by the M-integral. Crack growth leads to an increase of the M-integral, indicating progressive damage of the materials. Concerning the secondary cracks formed around a major crack, the results show that the M-integral is highly dependent on the numbers and locations of those secondary cracks. Shielding effect is mostly evident for microcracks with centres located just behind or vertically in line with the major crack tip. With the increasing number of microcracks, the shielding effect tends to decrease as reflected by the increasing M-integral value

Brain Activities Responding to Acupuncture at ST36 (zusanli) in Healthy Subjects: A Systematic Review and Meta-Analysis of Task-Based fMRI Studies

PurposeStomach 36 (ST36, zusanli) is one of the important acupoints in acupuncture. Despite clinical functional magnetic resonance imaging (fMRI) studies of ST36 acupuncture, the brain activities and the neural mechanism following acupuncture at ST36 remain unclear.MethodsLiterature searches were conducted on online databases, including MEDLINE, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wanfang database, WeiPu database, and China Biology Medicine, for task-based fMRI studies of acupuncture at ST36 in healthy subjects. Brain regions activated by ST36 acupuncture were systematically evaluated and subjected to seed-based d mapping meta-analysis. Subgroup analysis was conducted on control procedures, manual acupuncture, electrical acupuncture (EA), and acupuncture-specific activations. Meta-regression analysis was performed to explore the effects of needle retention time on brain activities following ST36 acupuncture stimulation. The activated brain regions were further decoded and mapped on large-scale functional networks to further decipher the clinical relevance of acupuncturing at ST36.ResultsA total of sixteen studies, involving a total of 401 right-handed healthy participants, that satisfied the inclusion criteria were included in the present meta-analysis. Meta-analysis showed that acupuncturing on ST36 positively activates the opercular part of the right inferior frontal gyrus (IFG.R), left superior temporal gyrus (STG.L), and right median cingulate/paracingulate gyri (MCG.R) regions. Needle retention time in an acupuncture session positively correlates with the activation of the left olfactory cortex, as shown in meta-regression analysis. Subgroup analysis revealed that EA stimulation may be a source of heterogeneity in the pooled results. Functional network mappings showed that the activated areas were mapped to the auditory network and salience network. Further functional decoding analysis showed that acupuncture on ST36 was associated with pain, secondary somatosensory, sound and language processing, and mood regulation.ConclusionAcupuncture at ST36 in healthy individuals positively activates the opercular part of IFG.R, STG.L, and MCG.R. The left olfactory cortex may exhibit positive needle retention time-dependent activities. Our findings may have clinical implications for acupuncture in analgesia, language processing, and mood disorders.Systematic Review Registrationhttps://inplasy.com/inplasy-2021-12-0035

J. Mater. Chem. A

Destructive gas generation with associated swelling has been the major challenge for the large-scale application of Li4Ti5O12 (LTO)-based lithium-ion batteries (LIBs), especially when the LIBs work at high temperature. Here we report a new kind of Li4Ti5O12-rutile TiO2 (LTO-RTO) hybrid nanowire array electrode that can be cycled at elevated temperatures. After assembling the optimized LTO-RTO hybrid array as the anode and commercial LiCoO2 (LCO) film as the cathode, the obtained lithium-ion full cell exhibits outstanding performance with an ultralong lifetime at 60 degrees C (similar to 83.6% of its initial capacity can be retained at the end of 500 cycles at similar to 2.5 C). Based on comparative experiments, we proposed a reasonable mechanism and, further, provided a reasonable verdict about the gas generation: the H-2 and CO generation from the LTO electrode are significantly associated with the (111) facet. The presence of more LTO (400) planes than (111) ones in the optimized LTO-RTO electrode is the essential reason for long-term cycling at 60 degrees C without gassing. Our work implies that an ability to tune the crystal facet orientation of electrode nanostructures will be meaningful in the practical design of next-generation high-stability LIBs.Destructive gas generation with associated swelling has been the major challenge for the large-scale application of Li4Ti5O12 (LTO)-based lithium-ion batteries (LIBs), especially when the LIBs work at high temperature. Here we report a new kind of Li4Ti5O12-rutile TiO2 (LTO-RTO) hybrid nanowire array electrode that can be cycled at elevated temperatures. After assembling the optimized LTO-RTO hybrid array as the anode and commercial LiCoO2 (LCO) film as the cathode, the obtained lithium-ion full cell exhibits outstanding performance with an ultralong lifetime at 60 degrees C (similar to 83.6% of its initial capacity can be retained at the end of 500 cycles at similar to 2.5 C). Based on comparative experiments, we proposed a reasonable mechanism and, further, provided a reasonable verdict about the gas generation: the H-2 and CO generation from the LTO electrode are significantly associated with the (111) facet. The presence of more LTO (400) planes than (111) ones in the optimized LTO-RTO electrode is the essential reason for long-term cycling at 60 degrees C without gassing. Our work implies that an ability to tune the crystal facet orientation of electrode nanostructures will be meaningful in the practical design of next-generation high-stability LIBs

Platelet P2Y12 is involved in murine pulmonary metastasis.

The involvement of platelets in tumor progression is well recognized. The depletion of circulating platelets or pharmacologic inhibitors of platelet activation decreases the metastatic potential of circulating tumor cells in metastasis mouse models. The platelet ADP receptor P2Y12 amplifies the initial hemostatic responses activated by a variety of platelet agonists and stabilizes platelet aggregation, playing a crucial role in granule secretion, integrin activation and thrombus formation. However, the relationship between P2Y12 and tumor progression is not clear. In our study, the Lewis Lung Carcinoma (LLC) spontaneous metastatic mouse model was used to evaluate the role of P2Y12 in metastasis. The results demonstrated that P2Y12 deficiency significantly reduced pulmonary metastasis. Further studies indicated that P2Y12 deficiency diminished the ability of LLC cells to induce platelet shape change and release of active TGFβ1 by a non-contact dependent mechanism resulting in a diminished, platelet-induced EMT-like transformation of the LLC cells, and that transformation probably is a prerequisite of LLC cell metastasis. Immunohistochemical analyses indicated an obvious P2Y12 deficiency related attenuation of recruitment of VEGFR1+ bone marrow derived cell clusters, and extracellular matrix fibronectin deposition in lungs, which presumably are required for pre-metastatic niche formation. In contrast to the LLC cells, non-epithelial melanoma B16 cells induced platelet aggregation in a cell number and P2Y12-dependent manner. Also, a platelet induced EMT-like transformation of B16 cells is dependent on P2Y12. In agreement with the LLC cell model, platelet P2Y12 deficiency also results in significantly less lung metastasis in the B16 melanoma experimental metastasis model. These results demonstrate that P2Y12 is a safe drug target for anti-thrombotic therapy, and that P2Y12 may serve as a new target for inhibition of tumor metastasis

Strain assisted electrocaloric effect in PbZr0.95Ti0.05O3 films on 0.7Pb(Mg1/3Nb2/3)O-3-0.3PbTiO(3) substrate

Solid state cooling technologies based on electrocaloric, magnetocaloric and mechanocaloric effects have received much attention during the past decade. To further improve the cooling efficiency and reduce the driving field, it is desirable to combine multiple effects in a single system. Here, we report on the caloric effects induced by both electric field and strain in PbZr0.95Ti0.05O3 films deposited on 0.7Pb(Mg1/3Nb2/3)O-3-0.3PbTiO(3) substrate. The isothermal entropy change (Delta S) induced by the antiferroelectric-ferroelectric phase transition of PbZr0.95Ti0.05O3 films is calculated to be 6.78 J K (1) kg(-1). Furthermore, the strain from 0.7Pb(Mg1/3Nb2/3)O-3-0.3PbTiO(3) substrate can reduce the electric field where Delta S reaches the maximum by as much as 50 kV/cm. The electrocaloric efficiency is also increased from 0.366 to 0.378 by the strain effect. The electrocaloric effect in an antiferroelectric material assisted by strain may lead to more efficient solid state cooling technology

Combination of clinical information and radiomics models for the differentiation of acute simple appendicitis and non simple appendicitis on CT images

Abstract To investigate the radiomics models for the differentiation of simple and non-simple acute appendicitis. This study retrospectively included 334 appendectomy cases (76 simple and 258 non-simple cases) for acute appendicitis. These cases were divided into training (n = 106) and test cohorts (n = 228). A radiomics model was developed using the radiomic features of the appendix area on CT images as the input variables. A CT model was developed using the clinical and CT features as the input variables. A combined model was developed by combining the radiomics model and clinical information. These models were tested, and their performance was evaluated by receiver operating characteristic curves and decision curve analysis (DCA). The variables independently associated with non-simple appendicitis in the combined model were body temperature, age, percentage of neutrophils and Rad-score. The AUC of the combined model was significantly higher than that of the CT model (P = 0.041). The AUC of the radiomics model was also higher than that of the CT model but did not reach a level of statistical significance (P = 0.053). DCA showed that all three models had a higher net benefit (NB) than the default strategies, and the combined model presented the highest NB. A nomogram of the combined model was developed as the graphical representation of the final model. It is feasible to use the combined information of clinical and CT radiomics models for the differentiation of simple and non-simple acute appendicitis

Unusual anisotropic magnetoresistance in charge-orbital ordered Nd0.5Sr0.5MnO3 polycrystals

Due to its potential application in magnetic recording and sensing technologies, the anisotropic magnetoresistance (AMR) effect has attracted lasting attention. Despite the long history, AMR effect has not been fully understood especially in the unconventional materials, such as perovskite manganites. Here, we report an unusual AMR effect in the charge-orbital ordered (COO) Nd0.5Sr0.5MnO3 polycrystals, which is observed when the magnetic field rotates in the plane that is perpendicular to the current (out-of-plane AMR). Despite being a polycrystalline sample where no anisotropy is expected, the resistivity shows a large irreversible drop with rotating magnetic field. A model has been proposed based on anisotropic magnetic field induced the melting of COO phase to explain the unusual out-of-plane AMR successfully. Our results demonstrate a new way for understanding the close relationship between phase separation and AMR effect in COO manganites. (C) 2014 AIP Publishing LLC

P2Y12 facilitates a TGF-β1-independent EMT-like transition of B16 cells, and experimental pulmonary metastasis by B16 cells.

<p>(<b>A</b>) Phase-contrast 10× and 20× micrographs of B16 tumor cells incubated with buffer, WT platelets, P2Y12^−/− platelets or 20ng/ml active TGF-β1, respectively for 48 hours. Incubation with WT platelets obviously induced B16 cells to undergo an EMT-like transition, P2Y12 deficient platelets did not induce an EMT-like transition of B16 cells. Interestingly, the recombinant active TGF-β1 induced the B16 cells to undergo a less extensive EMT-like morphologic change than was induced by the WT platelets. (<b>B</b>) The level of active TGF-β1 in the B16 conditioned medium was also measured by an ELISA. B16 cells induced significantly less release of active TGF-β1 from P2Y12 deficient platelets than from WT platelets. Each bar represents the mean ± SEM, and statistical significance was determined using a one-way AVONA (**p<0.01, n=3). (<b>C</b>) Each mouse from both groups (n=7 for each group) were injected with 2 × 10⁵ B16 cells via a tail vein. Twenty days after injection of the B16 cells, the, lungs were dissected from each mouse, and photographed. Images of visible metastatic foci are apparent in the photomicrographs. (<b>D</b>) Statistical analyses of the number of metastatic foci at the surface of the lung lobes. Each bar represents the mean ± SEM, and statistical significance was determined using the Student’s t test (**p<0.01, n=7 for each group). (<b>E</b>) Representative histochemical images (10×) of lung sections from wild-type and P2Y12 deficient mice.</p

P2Y12 deficiency decreases lung metastasis but has no effect on primary tumor growth in the LLC (Lewis lung carcinoma) spontaneous pulmonary metastasis model.

<p>Each group of 9 mice was injected intradermally with 2×10⁶ LLC cells. Subcutaneous primary tumors were removed from each mouse and weighed 14 days after implantation. One month after removal of the subcutaneous tumors, each mouse was dissected, and its lungs were removed, weighed, and photographed. (<b>A</b>) Representative images of gross metastatic lungs from each group of mice. (<b>B</b>) Representative images of tissue sections from metastatic lungs obtained from WT and P2Y12 deficient mice. The lungs were paraffin-embedded prior to sectioning. The sections were stained with hematoxylin and eosin. (<b>C</b>) The mean weights of the primary tumors from the WT and P2Y12^−/− groups. Each bar represents the mean ± SEM of the weights of all the subcutaneous tumors from each group of mice. There was no statistically significant difference between the mean tumor weights of the WT and P2Y12 deficient groups (n=9). (<b>D</b>) The mean weights of metastatic lungs from WT and P2Y12^−/− groups. Each bar represents the mean ± SEM. P2Y12 deficiency significantly inhibited pulmonary metastasis (*p<0.05, n=9).</p