To comprehend the fatigue failure mechanism at the fiber discontinuity in fiber-reinforced composites, it is necessary to evaluate the local mechanical behaviors. The fatigue strength depends on the ...stress distribution at the fiber inclusion corner. An improved advanced finite element method (IAFEM) is proposed for the stress intensity factor (SIF) analysis at the fiber inclusion corner. In the IAFEM, the element stiffness matrix of singular inclusion corner element (SICE) is obtained, and the singular elastic field at the tip of the fiber inclusion is determined. The effects of load direction, fiber distribution, fiber geometry, and material properties on SIFs are analyzed numerically using the IAFEM. The difference in stress field distribution between two-dimensional and three-dimensional fiber inclusions is discussed. The IAFEIM and calculation results can provide reference for fatigue strength analysis and preparation of composite materials.
In this study, we investigated whether COL4A3 mRNA expression levels were associated with clinical outcomes after treatment with a combination of gemcitabine (Gem)/
cis
-diamminedichloroplatinum(II) ...(CDDP) regimen for patients with advanced stage non-small cell lung cancer (NSCLC). Response and survival were correlated with the level of COL4A3 expression in 58 patients with advanced (stage IIIb or IV) NSCLC treated as part of a multicenter randomized trial with Gem 1,250 mg/m
2
on days 1 and 8 plus CDDP 100 mg/m
2
on day 1 every 3 weeks. mRNA was isolated from paraffin-embedded pretreatment primary tumor specimens, and relative expression levels of COL4A3/β-actin were measured using a quantitative reverse transcription-PCR (Taqman) system. COL4A3 expression was detectable in all tumors. There were no significant differences in COL4A3 levels by gender, age, performance status, weight loss, or tumor stage. The overall response rate was 45.8 %. There were no significant associations between COL4A3 expression and response. Median overall survival was significantly longer in patients with low COL4A3 expression tumors compared to patients with high expression tumors. COL4A3 expression, Eastern Cooperative Oncology Group performance status, and presence of weight loss were significant prognostic factors for survival in a Cox proportional hazards multivariable analysis. These data suggest that COL4A3 expression is a predictive factor for survival after CDDP/Gem therapy in advanced NSCLC. Although there was a trend toward decreased response with high COL4A3 mRNA levels, this difference failed to reach statistical significance. This result may reflect the impact of Gem and the requirement for COL4A3 expression for CDDP/Gem synergism or may be attributable to the relatively small patient sample size in this study. Prospective studies of COL4A3 as a predictive marker for activity of CDDP-based regimens in NSCLC are warranted.
Determination of triiodide diffusion coefficient, charge-transfer resistance and photovoltaic performance of the binary ionic liquid electrolyte of 1-methyl-3-propylimidazolium iodide (MPII) and ...1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF
4) for dye-sensitized solar cells (DSSCs) were performed at varying volume ratios of MPII/EMIMBF
4. Compared to pure MPII ionic liquid, the addition of EMIMBF
4 not only increased triiodide diffusion coefficient, but also decreased charge-transfer resistance at Pt/electrolyte interface, leading to the notably improved photovoltaic performance of DSSC. The highest photoelectric conversion efficiency of 4.99% was obtained under light intensity of 100
mW/cm
2 for the DSSC with the binary MPII/EMIMBF
4 ionic liquid electrolyte when the volume ratio of MPII/EMIMBF
4 was 50/50, which was much higher than that of pure MPII ionic liquid electrolyte (2.6%).
MicroRNA (miR)-145 is the most abundant miR in vascular smooth muscle cells (VSMCs). However, the effect of hyperglycemia on the regulation of miR-145 is unknown. We hypothesized that the ...hyperglycemic condition activates a proinflammatory response that mediates the expression of miR-145 in VSMCs. We investigated whether miR-145 serves as a critical regulator to regulate the downstream proliferation factors (including Kruppel-like factor 4 Klf4 and myocardin) in VSMCs under hyperglycemic conditions. Human coronary artery smooth muscle cells (HCASMCs) were cultured under high glucose conditions. Sustained high glucose at 25 mmol/L significantly decreased the expression of miR-145 in HCASMCs. High glucose significantly increased angiotensin II (Ang II) secretion from HCASMCs and Ang II suppressed miR-145 expression in HCASMCs. Ang II repression of miR145 expression resulted in increased Klf4 and decreased myocardin expression under conditions of high glucose. Overexpression of miR-145 significantly decreased Klf4 and increased myocardin expression and inhibited HCASMC proliferation and migration induced by a high glucose state. Balloon injury of the carotid artery in diabetic rats was performed to investigate miR-145, Klf and myocardin expression. The expression of miR-145 was maximally increased at 7 d after carotid injury and gradually declined thereafter. Overexpression of miR-145 and treatment with valsartan reversed Klf4 and myocardin protein expression induced by balloon injury and improved vascular injury. In conclusion, our study reveals that Ang II downregulates miR-145 to regulate Klf4 and myocardin expression in HCASMCs under high glucose conditions. Ang II plays a critical role in the regulation of miR-145 under hyperglycemic conditions.
The Huaibei coalfield is in the East China Economic Area, which is rich in coal and gas resources. However, hundreds of coal and gas outburst accidents have occurred because of the complex geological ...structures of the coalfield. Based on theoretical analysis and field statistics, the characteristics of regional geological structures and the coal measure strata evolution in the Huaibei coalfield were researched, and gas resource distribution and gas parameters were statistically analyzed to determine the dominant controlling factors of gas occurrence and gas dynamic disaster. The results indicated that the Huaibei coalfield has undergone complex tectonic evolution, causing obvious differences in gas storage in different blocks of different mining areas, which exhibits a pattern of high amounts of gas in the south and east, and low amounts of gas in the north and west. The coal seam and gas occurrence have a bipolar distribution in the coalfield caused by multiple tectonic movements, and they are deeply buried. Horizontal tectonic stress plays a dominant role in gas outburst, and the thermal evolution and trap effects of magma intrusion increase the possibility and extent of gas outburst. Considering coal seam and gas occurrence characteristics in the coalfield, we propose a new technology for deep coal reservoir reconstruction which combined present underground regional gas control methods and surface well extraction methods. The technology has three effects: developing gas resources, improving coal mining safety level and reducing greenhouse gas emissions, which has been practiced to be effective in coal mines in the Huaibei coalfield.
•Proposed a design structure with an array of pyramidal nanostructures for solar radiation absorption.•The nanostructure is made of a natural hyperbolic metamaterial Bi2Te3 on a substrate submerged ...in water.•Predicted an absorptance exceeding 99.9% from 300 to 2400 nm based on the design.•Explained the underlying mechanisms by the slow-light and gradient index effects.•Performed a parametric study to analyze the geometry and material’s effects.
A perfect absorber design is proposed here that uses a periodic array of pyramidal nanostructures, made from a natural hyperbolic material bismuth telluride (Bi2Te3) on a substrate. A numerical study is carried out to investigate the absorption of solar radiation and to determine the suitable ranges of the geometric parameters for the proposed structure submerged in water. The results show that the proposed structure can achieve absorptance values greater than 99.9% in the wavelength range of 300–2400 nm, which covers most of the solar radiation spectrum. The underlying mechanisms are attributed to the combination of the slow-light effect and the gradient index effect. Optical properties of this type of absorber are affected by the geometry of the nanostructure (such as the height and the top and bottom widths of the pyramid), the distance between two adjacent pyramids, as well as the material and thickness of the substrate. Nevertheless, extremely high absorptance can be achieved even with some variations of these parameters. This study could open a route for effectively harvesting solar energy in photothermal conversion processes in water.
•A 3D crack front element is developed by using numerical eigen-solutions.•3D solid containing curved cracks is considered based on coordinate transformation.•The present method is insensitive to the ...sizes of the super crack front elements.•The new element can be applied to the interfacial and anisotropic fractures.
A super crack front element containing a part of a curved crack front is established to solve the stress intensity factors of three-dimensional curved cracks by using the numerical series eigen-solutions. The element can be directly incorporated into the existing three-dimensional linear brick elements without using transition elements. The intensity of singular stress fields is determined as the system unknowns appearing as nodal displacement values. Numerical studies are conducted to demonstrate the simplicity and effectiveness of the proposed technique in handling typical three-dimensional fracture problems of curved cracks. It is proved that the super crack front element can avoid mesh refinement near the crack front domain without loss of calculation accuracy and velocity of convergence, and can be used to deal with interfacial and anisotropic fracture problems directly.
Background
The determining risk factors for patients with squamous cell carcinoma of the hard palate are not well verified.
Methods
Medical records from our facility of all patients with squamous ...cell carcinoma of the hard palate receiving curative surgery between March 2003 and May 2009 were reviewed.
Results
Seventy-eight patients were enrolled in the study. The 5 year disease-free and overall survival rates were 49.8 and 49.7%, respectively. The 5 year disease-free and overall survival rates were statistically different between positive/close margins and negative margins (24.6% vs. 65.4%,
P
= 0.02; 20.1% vs. 63.1%,
P
= 0.001, respectively), with and without soft palate invasion (38.8% vs. 68.9%,
P
= 0.02; 27.4% vs. 77.5%,
P
= 0.001, respectively), and soft palate invasion patients with and without perineural invasion (10.4% vs. 52.8%,
P
= 0.02; 0% vs. 38.1%,
P
= 0.008, respectively). The rate of positive nodal metastasis for T3 and T4 tumors was 44%. For the tumor with soft palate invasion, the rate of positive nodal metastasis was 29%. After multivariate analyses, soft palate invasion and positive/close margins were the determining risk factors for disease-free and overall survival.
Conclusions
Soft palate invasion and positive/close margins were the determining risk factors for disease-free and overall survival in patients with squamous cell carcinoma of the hard palate. Elective neck dissection is suggested for advanced primary tumors (T3 or T4) or tumors with soft palate invasion.
To the editor：Mucosa-associated lymphoid tissue （MALT） lymphoma is a low grade B-cell extra-nodal lymphoma from margtnal zone.Lung location is rare and represents 3%-4% of all cases.1 There is no ...uniform treatment for pulmonary-MALT （p-MALT） lymphoma.This is the report of p-MALT without any extra-pulmonary lesions of MALT lymphoma that was regressed with clarithromycin （CAM） （500 mg/d） treatment in China.
Anshen Dingzhi prescription (ADP), which was first published in the masterpiece of traditional Chinese Medicine in the Qing Dynasty, "Yi Xue Xin Wu" (1732 CE), is documented to interrupt ...panic-related disorders. However, the mechanism of its action is still not clear.
This study aims to investigate the effects of ADP on post-traumatic stress disorder (PTSD)-like behaviors and explore the mechanism from perspective of sirtuin1 (SIRT1)-peroxisome proliferator-activated receptor gamma co-activator 1 alpha (PGC-1α)-dependent mitochondrial function.
The changes of SIRT1-PGC-1α signal and mitochondrial function were evaluated in the hippocampus of mice receiving single prolonged stress (SPS). Later, the roles of this signaling pathway played in fear memory generalization and anxiety-like behavior in SPS mice was investigated using two agonists of this signaling pathway. On this basis, the effects of ADP (36.8 mg/kg) with definite therapeutic effects, on mitochondrial function were investigated and further confirmed by a SIRT1 inhibitor. Finally, the possible components of ADP targeting PGC-1α were monitored through bioinformatics.
Compared with control mice, SIRT1-PGC-1α signal in the hippocampus was impaired in SPS mice, accompanied with dysfunction of mitochondria and abnormal expression of synaptic proteins. The agonists of SIRT1-PGC-1α signal, ZLN005, as well as resveratrol improved the behavioral changes of mice caused by SPS, reversed the decline of proteins in SIRT1-PGC-1α signal, mitochondrial dysfunction, and the abnormal expression of synaptic proteins. The fingerprint was established for the quality control of ADP. At a dose of 36.8 mg/kg, ADP could prevent fear memory generalization and anxiety-like behavior in SPS mice. Mechanically, ADP promoted SIRT1-PGC-1α signal and repaired mitochondrial function. Importantly, SIRT1 inhibitor, selisistat eliminated the ameliorative effects of ADP on behavioral and mitochondrial function. Through molecular docking simulation, the brain-entering components of ADP, including malkangunin, Rg5, fumarine, frutinone A, celabenzine, and inermin had high binding energy with PGC-1α.
Dysfunction of SIRT1-PGC-1α-dependent mitochondrial function is attributed to SPS-triggered fear generalization and anxiety-like behavior, and ADP could improve PTSD-like behaviors likely through activating this signaling pathway.
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