Limited models have been devised using Stern theory to obtain the repulsive force from a double layer.Moreover,an elastoplastic model that differentiates various swelling behaviors because of exchangeable cation speci...Limited models have been devised using Stern theory to obtain the repulsive force from a double layer.Moreover,an elastoplastic model that differentiates various swelling behaviors because of exchangeable cation species is yet to be devised.In this study,we introduce a novel multiphysics elastoplastic model for swelling geomaterials that incorporates Stern theory.This model considered the finite size of exchangeable cations and specific adsorption phenomena,which are typically overlooked in existing models.Based on Stern theory,we derived the repulsive force from the double layer and integrated the force into the elastoplastic expansive bedrock model,which addresses electroechemoemechanical phenomena in the interlayer.The proposed model differentiated swelling behaviors based on the type of exchangeable cation species by incorporating these phenomena.To validate the model,a onedimensional(1D)numerical analysis was performed,demonstrating its capability to describe various swelling behaviors due to different exchangeable cation species through comparison with free swelling test results of bentonite.Additionally,a parametric study was conducted to elucidate the effect of the hydrated radius of exchangeable cations and the specific adsorption potential on swelling behavior,analyzed from the perspective of the equilibrium of charge distribution near the mineral surface.展开更多
MicroRNAs （miRNAs） are a class of non-coding RNAs that are believed to have a significant role in tumorigenesis and cancer metastasis. Cancer stem cells play a major role in tumor recurrence, metastasis, and drug re...MicroRNAs （miRNAs） are a class of non-coding RNAs that are believed to have a significant role in tumorigenesis and cancer metastasis. Cancer stem cells play a major role in tumor recurrence, metastasis, and drug resistance. Research has shown that miRNAs can promote or inhibit the sternness of cancer stem cells and regulate the differentiation and self-renewal of cancer stem cells. In this article, the phenotype and regulatory mechanisms of miRNAs in cancer stem cells will be described, together with an explanation of their potential role in tumor diagnosis and treatment.展开更多
Because of their strong proliferative capacity and multi-potency, placenta-derived mesenchymal stem cells have gained interest as a cell source in the field of nerve damage repair. In the present study, human placenta...Because of their strong proliferative capacity and multi-potency, placenta-derived mesenchymal stem cells have gained interest as a cell source in the field of nerve damage repair. In the present study, human placenta-derived mesenchymal stem ceils were induced to differentiate into neural stem cells, which were then transplanted into the spinal cord after local spinal cord injury in rats. The motor functional recovery and pathological changes in the injured spinal cord were observed for 3 successive weeks. The results showed that human placenta-derived mesenchymal stem cells can differentiate into neuron-like cells and that induced neural stem cells contribute to the restoration of injured spinal cord without causing transplant rejection. Thus, these cells promote the recovery of motor and sensory functions in a rat model of spinal cord injury. Therefore, human placenta-derived mesenchymal stem cells may be useful as seed cells during the repair of spinal cord injury.展开更多
microRNAs （miRNAs） play an important regulatory role in the self-renewal and differentiation of stem cells. In this study, we examined the effects of miRNA-124 （miR-124） overexpression in bone marrow-derived mesen...microRNAs （miRNAs） play an important regulatory role in the self-renewal and differentiation of stem cells. In this study, we examined the effects of miRNA-124 （miR-124） overexpression in bone marrow-derived mesenchymal stem cells. In particular, we focused on the effect of overexpression on the differentiation of bone marrow-derived mesenchymal stem cells into neurons. First, we used GeneChip technology to analyze the expression of miRNAs in bone marrow-derived mesen- chymal stem cells, neural stem cells and neurons, miR-124 expression was substantially reduced in bone marrow-derived mesenchymal stem cells compared with the other cell types. We con- structed a lentiviral vector overexpressing miR-124 and transfected it into bone marrow-derived mesenchymal stem cells. Intracellular expression levels of the neuronal early markers [3-III tu- bulin and microtubule-associated protein-2 were significantly increased, and apoptosis induced by oxygen and glucose deprivation was reduced in transfected cells. After miR-124-transfected bone marrow-derived mesenchymal stem cells were transplanted into the injured rat spinal cord, a large number of cells positive for the neuronal marker neurofilament-200 were observed in the transplanted region. The Basso-Beattie-Bresnahan locomotion scores showed that the motor function of the hind limb of rats with spinal cord injury was substantially improved. These re- sults suggest that miR-124 plays an important role in the differentiation of bone marrow-derived mesenchymal stem cells into neurons. Our findings should facilitate the development of novel strategies for enhancing the therapeutic efficacy of bone marrow-derived mesenchymal stem cell transplantation for spinal cord injury.展开更多
Objective： Correct nutritional assessment is essential for leukemia patients after hematopoietic stem cell transplantation （HSCT）. This study aimed to investigate the best nutritional assessment method for leukemia...Objective： Correct nutritional assessment is essential for leukemia patients after hematopoietic stem cell transplantation （HSCT）. This study aimed to investigate the best nutritional assessment method for leukemia patients after HSCT, and find the possible nutritional risk of the patients during the transplantation process in order to intervene in the patients with nutritional risks and undernourished patients timely, so that the entire transplantation process could be successfully completed. Methods： A prospective study was performed in 108 leukemia patients after HSCT, and different nutritional assessment methods, including nutritional risk screening 2002 （NRS2002）, mini nutritional assessment （MNA）, subjective globe assessment （SGA） and malnutritional universal screening tools （MUST）, were used. The associations between nutritional status of these patients and nutritional assessment methods were analyzed. Results： A total of 108 patients completed SGA, and 99 patients completed NRS2002, MNA and MUST. During the treatment process, 85.2% of the patients lost weight, wherein, 50% lost weight greater than 5%, and 42.6% had significantly reduced food intake. For nutritional risk assessment, the positive rates of NRS2002, MNA and MUST were 100%, 74.7% and 63.6%, respectively. There was a significant difference （P〈0.05） among the positive rates of NRS2002, MNA and MUST. In undernutrition assessment, the positive rate of SGA （83.3%） was significantly higher than that of MNA （17.2%） （P〈0.05）, and the incidence rate of nutritional risk among leukemia patients _〈30 years old was greater than that of patients 〉30 years old （P〈0.05）. Conclusions： Patients with leukemia were in poor nutritional status during and after HSCT. The leukemia patients 〈30 years old had a greater incidence rate of nutritional risk. As nutritional risk screening tool, the specificity of NRS2002 is not high, but it can be used for evaluating nutritional deficiencies. MNA is a good nutritional risk screening tool, but not an adequate tool for nutritional assessment. If assessment of undernutrition is necessary, the combination of all these screening tools and clinical laboratory indicators should he applied to improve accuracy.展开更多
In order to solve the severe vibration problems of an ocean engineering ship with a full-revolving propulsion system, the navigation tests, including forced vibration response test and modal test, are carded out in it...In order to solve the severe vibration problems of an ocean engineering ship with a full-revolving propulsion system, the navigation tests, including forced vibration response test and modal test, are carded out in its stem. It is concluded from the comparison of the time-domain waveform and spectrum from different measurement points that three main factors lead to a high-level stern vibration. Firstly, the specific dynamic stiffness of a water tank is relatively small compared with its neighbor hold, which makes it act like a vibration isolator preventing vibrational energy transmitting to the main hold. Secondly, there exists high-density local modes in the working frequency range of the main engine and thus the local resonance occurs. Thirdly, the abnormal engagement of gears caused by the large deflection of the shaft bearing due to its low mounting rigidity leads to violent extra impulse excitations at high speeds. Then the modification against the dynamic defects is given by simply improving the specific stiffness of the water tanks. And the effect is validated by the FEM calculation. Some important experience is obtained with the problems being solved, which is useful in the design of ships with the same propulsion system. It is also believed that the dynamic consideration is as important as the static analysis for the ships, and that most of the vibration problems may be avoided with a proper acoustic design.展开更多
基金supported by the Japan Tunnelling Association and by JST SPRING(Grant Nos.JTA-R6-G1 and JPMJSP2114).
文摘Limited models have been devised using Stern theory to obtain the repulsive force from a double layer.Moreover,an elastoplastic model that differentiates various swelling behaviors because of exchangeable cation species is yet to be devised.In this study,we introduce a novel multiphysics elastoplastic model for swelling geomaterials that incorporates Stern theory.This model considered the finite size of exchangeable cations and specific adsorption phenomena,which are typically overlooked in existing models.Based on Stern theory,we derived the repulsive force from the double layer and integrated the force into the elastoplastic expansive bedrock model,which addresses electroechemoemechanical phenomena in the interlayer.The proposed model differentiated swelling behaviors based on the type of exchangeable cation species by incorporating these phenomena.To validate the model,a onedimensional(1D)numerical analysis was performed,demonstrating its capability to describe various swelling behaviors due to different exchangeable cation species through comparison with free swelling test results of bentonite.Additionally,a parametric study was conducted to elucidate the effect of the hydrated radius of exchangeable cations and the specific adsorption potential on swelling behavior,analyzed from the perspective of the equilibrium of charge distribution near the mineral surface.
文摘MicroRNAs （miRNAs） are a class of non-coding RNAs that are believed to have a significant role in tumorigenesis and cancer metastasis. Cancer stem cells play a major role in tumor recurrence, metastasis, and drug resistance. Research has shown that miRNAs can promote or inhibit the sternness of cancer stem cells and regulate the differentiation and self-renewal of cancer stem cells. In this article, the phenotype and regulatory mechanisms of miRNAs in cancer stem cells will be described, together with an explanation of their potential role in tumor diagnosis and treatment.
基金supported by a grant from the Scientific Research Program of Liaoning Provincial Science and Technology Ministry in China,No.2012225014
文摘Because of their strong proliferative capacity and multi-potency, placenta-derived mesenchymal stem cells have gained interest as a cell source in the field of nerve damage repair. In the present study, human placenta-derived mesenchymal stem ceils were induced to differentiate into neural stem cells, which were then transplanted into the spinal cord after local spinal cord injury in rats. The motor functional recovery and pathological changes in the injured spinal cord were observed for 3 successive weeks. The results showed that human placenta-derived mesenchymal stem cells can differentiate into neuron-like cells and that induced neural stem cells contribute to the restoration of injured spinal cord without causing transplant rejection. Thus, these cells promote the recovery of motor and sensory functions in a rat model of spinal cord injury. Therefore, human placenta-derived mesenchymal stem cells may be useful as seed cells during the repair of spinal cord injury.
基金supported by the National Natural Science Foundation of China,No.81070971
文摘microRNAs （miRNAs） play an important regulatory role in the self-renewal and differentiation of stem cells. In this study, we examined the effects of miRNA-124 （miR-124） overexpression in bone marrow-derived mesenchymal stem cells. In particular, we focused on the effect of overexpression on the differentiation of bone marrow-derived mesenchymal stem cells into neurons. First, we used GeneChip technology to analyze the expression of miRNAs in bone marrow-derived mesen- chymal stem cells, neural stem cells and neurons, miR-124 expression was substantially reduced in bone marrow-derived mesenchymal stem cells compared with the other cell types. We con- structed a lentiviral vector overexpressing miR-124 and transfected it into bone marrow-derived mesenchymal stem cells. Intracellular expression levels of the neuronal early markers [3-III tu- bulin and microtubule-associated protein-2 were significantly increased, and apoptosis induced by oxygen and glucose deprivation was reduced in transfected cells. After miR-124-transfected bone marrow-derived mesenchymal stem cells were transplanted into the injured rat spinal cord, a large number of cells positive for the neuronal marker neurofilament-200 were observed in the transplanted region. The Basso-Beattie-Bresnahan locomotion scores showed that the motor function of the hind limb of rats with spinal cord injury was substantially improved. These re- sults suggest that miR-124 plays an important role in the differentiation of bone marrow-derived mesenchymal stem cells into neurons. Our findings should facilitate the development of novel strategies for enhancing the therapeutic efficacy of bone marrow-derived mesenchymal stem cell transplantation for spinal cord injury.
文摘Objective： Correct nutritional assessment is essential for leukemia patients after hematopoietic stem cell transplantation （HSCT）. This study aimed to investigate the best nutritional assessment method for leukemia patients after HSCT, and find the possible nutritional risk of the patients during the transplantation process in order to intervene in the patients with nutritional risks and undernourished patients timely, so that the entire transplantation process could be successfully completed. Methods： A prospective study was performed in 108 leukemia patients after HSCT, and different nutritional assessment methods, including nutritional risk screening 2002 （NRS2002）, mini nutritional assessment （MNA）, subjective globe assessment （SGA） and malnutritional universal screening tools （MUST）, were used. The associations between nutritional status of these patients and nutritional assessment methods were analyzed. Results： A total of 108 patients completed SGA, and 99 patients completed NRS2002, MNA and MUST. During the treatment process, 85.2% of the patients lost weight, wherein, 50% lost weight greater than 5%, and 42.6% had significantly reduced food intake. For nutritional risk assessment, the positive rates of NRS2002, MNA and MUST were 100%, 74.7% and 63.6%, respectively. There was a significant difference （P〈0.05） among the positive rates of NRS2002, MNA and MUST. In undernutrition assessment, the positive rate of SGA （83.3%） was significantly higher than that of MNA （17.2%） （P〈0.05）, and the incidence rate of nutritional risk among leukemia patients _〈30 years old was greater than that of patients 〉30 years old （P〈0.05）. Conclusions： Patients with leukemia were in poor nutritional status during and after HSCT. The leukemia patients 〈30 years old had a greater incidence rate of nutritional risk. As nutritional risk screening tool, the specificity of NRS2002 is not high, but it can be used for evaluating nutritional deficiencies. MNA is a good nutritional risk screening tool, but not an adequate tool for nutritional assessment. If assessment of undernutrition is necessary, the combination of all these screening tools and clinical laboratory indicators should he applied to improve accuracy.
基金financially supported by the National Natural Science Foundation of China(Grant No.51109131)
文摘In order to solve the severe vibration problems of an ocean engineering ship with a full-revolving propulsion system, the navigation tests, including forced vibration response test and modal test, are carded out in its stem. It is concluded from the comparison of the time-domain waveform and spectrum from different measurement points that three main factors lead to a high-level stern vibration. Firstly, the specific dynamic stiffness of a water tank is relatively small compared with its neighbor hold, which makes it act like a vibration isolator preventing vibrational energy transmitting to the main hold. Secondly, there exists high-density local modes in the working frequency range of the main engine and thus the local resonance occurs. Thirdly, the abnormal engagement of gears caused by the large deflection of the shaft bearing due to its low mounting rigidity leads to violent extra impulse excitations at high speeds. Then the modification against the dynamic defects is given by simply improving the specific stiffness of the water tanks. And the effect is validated by the FEM calculation. Some important experience is obtained with the problems being solved, which is useful in the design of ships with the same propulsion system. It is also believed that the dynamic consideration is as important as the static analysis for the ships, and that most of the vibration problems may be avoided with a proper acoustic design.
