55 research outputs found
Near-infrared photoresponse sensitization of solvent additive processed poly(3-hexylthiophene)/fullerene solar cells by a low band gap polymer
With the aim of extending the photoresponse of the poly(3-hexylthiophene)/[6,6]-phenyl-C61-butyric acid methyl ester photovoltaic system into the near-infrared region, a low band gap polymer poly [2,1,3-benzothiadiazole-4,7-diyl[4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b\u27]dithiophene-2, 6-diyl]] was incorporated to make ternary blend solar cells. Solvent additive 1,8-diiodooctane (DIO) was applied to optimize the phase separation in a one-step active layer preparation. Devices fabricated with DIO additive demonstrate an improvement of device power conversion efficiency by 17%, which can be attributed to favorable microscopic structure of the ternary blend with 1:1:0.2 composition processed with DIO and extended absorption on the red side of the visible spectrum up to 900 nm
Biomechanical analysis of sandwich vertebrae in osteoporotic patients: finite element analysis
ObjectiveThe aim of this study was to investigate the biomechanical stress of sandwich vertebrae (SVs) and common adjacent vertebrae in different degrees of spinal mobility in daily life.Materials and methodsA finite element model of the spinal segment of T10-L2 was developed and validated. Simultaneously, T11 and L1 fractures were simulated, and a 6-ml bone cement was constructed in their center. Under the condition of applying a 500-N axial load to the upper surface of T10 and immobilizing the lower surface of L2, moments were applied to the upper surface of T10, T11, T12, L1, and L2 and divided into five groups: M-T10, M-T11, M-T12, M-L1, and M-L2. The maximum von Mises stress of T10, T12, and L2 in different groups was calculated and analyzed.ResultsThe maximum von Mises stress of T10 in the M-T10 group was 30.68 MPa, 36.13 MPa, 34.27 MPa, 33.43 MPa, 26.86 MPa, and 27.70 MPa greater than the maximum stress value of T10 in the other groups in six directions of load flexion, extension, left and right lateral bending, and left and right rotation, respectively. The T12 stress value in the M-T12 group was 29.62 MPa, 32.63 MPa, 30.03 MPa, 31.25 MPa, 26.38 MPa, and 26.25 MPa greater than the T12 stress value in the other groups in six directions. The maximum stress of L2 in M-T12 in the M-L2 group was 25.48 MPa, 36.38 MPa, 31.99 MPa, 31.07 MPa, 30.36 MPa, and 32.07 MPa, which was greater than the stress value of L2 in the other groups. When the load is on which vertebral body, it is subjected to the greatest stress.ConclusionWe found that SVs did not always experience the highest stress. The most stressed vertebrae vary with the degree of curvature of the spine. Patients should be encouraged to avoid the same spinal curvature posture for a long time in life and work or to wear a spinal brace for protection after surgery, which can avoid long-term overload on a specific spine and disrupt its blood supply, resulting in more severe loss of spinal quality and increasing the possibility of fractures
Phosphoprotein Phosphatase 1 Is Required for Extracellular Calcium-Induced Keratinocyte Differentiation
Extracellular calcium is a major regulator of keratinocyte differentiation in vitro and appears to play that role in vivo, but the mechanism is unclear. We have previously demonstrated that, following calcium stimulation, PIP5K1α is recruited by the E-cadherin-β-catenin complex to the plasma membrane where it provides the substrate PIP2 for both PI3K and PLC-γ1. This signaling pathway is critical for calcium-induced generation of second messengers including IP3 and intracellular calcium and keratinocyte differentiation. In this study, we explored the upstream regulatory mechanism by which calcium activates PIP5K1α and the role of this activation in calcium-induced keratinocyte differentiation. We found that treatment of human keratinocytes in culture with calcium resulted in an increase in serine dephosphorylation and PIP5K1α activation. PP1 knockdown blocked extracellular calcium-induced increase in serine dephosphorylation and activity of PIP5K1α and induction of keratinocyte differentiation markers. Knockdown of PLC-γ1, the downstream effector of PIP5K1α, blocked upstream dephosphorylation and PIP5K1α activation induced by calcium. Coimmunoprecipitation revealed calcium induced recruitment of PP1 to the E-cadherin-catenin-PIP5K1α complex in the plasma membrane. These results indicate that PP1 is recruited to the extracellular calcium-dependent E-cadherin-catenin-PIP5K1α complex in the plasma membrane to activate PIP5K1α, which is required for PLC-γ1 activation leading to keratinocyte differentiation
Acupuncture Modulates the Functional Connectivity of the Default Mode Network in Stroke Patients
Abundant evidence from previous fMRI studies on acupuncture has revealed significant modulatory effects at widespread brain regions. However, few reports on the modulation to the default mode network (DMN) of stroke patients have been investigated in the field of acupuncture. To study the modulatory effects of acupuncture on the DMN of stroke patients, eight right hemispheric infarction and stable ischemic stroke patients and ten healthy subjects were recruited to undergo resting state fMRI scanning before and after acupuncture stimulation. Functional connectivity analysis was applied with the bilateral posterior cingulate cortices chosen as the seed regions. The main finding demonstrated that the interregional interactions between the ACC and PCC especially enhanced after acupuncture at GB34 in stroke patients, compared with healthy controls. The results indicated that the possible mechanisms of the modulatory effects of acupuncture on the DMN of stroke patients could be interpreted in terms of cognitive ability and motor function recovery
Mudskipper genomes provide insights into the terrestrial adaptation of amphibious fishes
Mudskippers are amphibious fishes that have developed morphological and physiological adaptations to match their unique lifestyles. Here we perform whole-genome sequencing of four representative mudskippers to elucidate the molecular mechanisms underlying these adaptations. We discover an expansion of innate immune system genes in the mudskippers that may provide defence against terrestrial pathogens. Several genes of the ammonia excretion pathway in the gills have experienced positive selection, suggesting their important roles in mudskippers’ tolerance to environmental ammonia. Some vision-related genes are differentially lost or mutated, illustrating genomic changes associated with aerial vision. Transcriptomic analyses of mudskippers exposed to air highlight regulatory pathways that are up- or down-regulated in response to hypoxia. The present study provides a valuable resource for understanding the molecular mechanisms underlying water-to-land transition of vertebrates
Land Use Transitions under Rapid Urbanization in Chengdu-Chongqing Region: A Perspective of Coupling Water and Land Resources
Land resources and water resources are the important material basis of economic and social development, and their pattern determines the pattern of development. Based on the panel data of the Chengdu–Chongqing Economic Circle from 2011 to 2018, this paper evaluates the matching degree of water and land resources, and their respective matching degrees with the economic development in the Chengdu–Chongqing Economic Circle with the Gini coefficient method. Based on the two-way fixed effect model, an extended Cobb–Douglas production function model is established to analyze the sensitivity of economic growth to land and water factors. In addition, the restriction degree of water and land resources to the economic development of the Chengdu–Chongqing Economic Circle is measured quantitatively by using the growth damping coefficient. The results show that the water and land resources and economic development of the Chengdu–Chongqing Economic Circle have a high matching degree, but the inner cities have a great difference. The contribution of water resources to economic growth is greater than that of land resources. Both of them have a little growth drag, which shows that industrial development has disposed of the dependence of water and land resources. The development of the Chengdu–Chongqing Economic Circle needs to play the role of technological progress in promoting economic growth, and at the same time optimize the use of water and land resources to reduce its constraints on the economic growth. Finally, the policy suggestions of matching water and land resources and economic growth in different regions are put forward
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p120‐catenin is required for regulating epidermal proliferation, differentiation, and barrier function
p120-catenin (p120) is an important regulator in the function and stability of E-cadherin. However, the role of p120 in the epidermis is unclear. Previous studies have shown that globally knockout of p120 caused increased epidermal proliferation but little changes in epidermal differentiation and permeability. In the present study, we generated a conditional knockout mouse model and examined epidermal proliferation, differentiation and permeability. The results showed that conditional knockout of p120 in the epidermis caused not only increased epidermal proliferation but also decreased epidermal differentiation and increased permeability. These data suggest that p120 is required for suppressing epidermal proliferation, promoting epidermal differentiation and maintaining permeability barrier function of the epidermis
色纺纱线中纤维混色比例的图像检测
In order to solve the problems of the empirical spadework and time consuming when confirming the proportions of the colored fibers in the colored spun yarns,with the help of the video microscopy and image processing technology,a novel method based on a clustering algorithm is proposed to classify the color fibers and inspect the proportions of different color fibers. Firstly,the colored spun yarns are untwisted into the fibers,the colored fibers are arranged on the slide under the mild tension, and the corresponding images are captured by the video microscopy. Secondly,the gray projection method is adopted to localize the colored fibers,and the average value of R,G,B of all pixels in the center line of each colored fiber is extracted as a feature vector to characterize the colored fiber respectively. Finally, the feature vectors in RGB model are converted to the L* a* b* color model,a clustering algorithm by searching density peaks is applied into classifying the colored fibers and the proportions of each color fibers are calculated. Experiments results demonstrate that the proposed method can inspect the colors and proportions of colored fibers in the colored spun yarns with a satisfactory accuracy
Research Progress on Anthocyanin-Mediated Regulation of ‘Black’ Phenotypes of Plant Organs
The color pattern is one of the most important characteristics of plants. Black stands out among the vibrant colors due to its rare and distinctive nature. While some plant organs appear black, they are, in fact, dark purple. Anthocyanins are the key compounds responsible for the diverse hues in plant organs. Cyanidin plays an important role in the deposition of black pigments in various plant organs, such as flower, leaf, and fruit. A number of structural genes and transcription factors are involved in the metabolism of anthocyanins in black organs. It has been shown that the high expression of R2R3-MYB transcription factors, such as PeMYB7, PeMYB11, and CsMYB90, regulates black pigmentation in plants. This review provides a comprehensive overview of the anthocyanin pathways that are involved in the regulation of black pigments in plant organs, including flower, leaf, and fruit. It is a great starting point for further investigation into the molecular regulation mechanism of plant color and the development of novel cultivars with black plant organs
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