The ultrastructures of the root protophleom sieve element at different developmental stages of Arabidopsis thaliana L. were investigated using the technique of high pressure freezing and freeze substitution fixing spe...The ultrastructures of the root protophleom sieve element at different developmental stages of Arabidopsis thaliana L. were investigated using the technique of high pressure freezing and freeze substitution fixing specimen. The results show that in the development of the sieve elements, the nuclei undergo typical characteristics of the programmed cell death (PCD): the nuclear envelopes form emboli, the chromatin condenses and aggregates towards the nuclear envelope, which degrades and fully disappears later. Before the nucleus degradation, neither the nuclear envelope undulation, nucleus lobe nor marked dilation (or bleb) of perinuclear space could be observed. In the cytoplasm of the mature sieve element, there are starch-like granules separately sheathed with a layer of membrane and usually with mitochondria around. These gnanules seem to provide substrates to mitochondria in their function. Small vacuoles originate from endoplasmic reticulum (ER), and no bigger vacuole was found.展开更多
The ultrastructure of the vegetative cells of Nostoc flagelliforme Born. et Flah. was investigated with high pressure freezing and freeze substitution technique and compared with the results obtained by using conv...The ultrastructure of the vegetative cells of Nostoc flagelliforme Born. et Flah. was investigated with high pressure freezing and freeze substitution technique and compared with the results obtained by using conventional preparation methods. During the processes of chemical fixation, dehydration and embedding, the cell structures might be more artificially modified than that obtained from high pressure freezing and freeze substitution. With the present method, the sheath of N. flagelliforme could be well penetrated and no extra big space could exist between the cell and the sheath. The cell protoplasm rarely shrinked. Some fine structures of cell inclusions and unit membranes became visualized. Many bacteria were harbored in the sheath. In addition, the presence of big vacuoles in the cell of N. flagelliforme as well as the presence of bacteria in the sheath shown in the present preparation for cyanobacteria has not been described so far in the literature.展开更多
Silicon carbide ceramics were prepared with SiC powder treated by the fluidized bed opposed jet mill as raw materials, and the effects of the ultra-fine treatment mechanism on the compaction and sintering behavior of ...Silicon carbide ceramics were prepared with SiC powder treated by the fluidized bed opposed jet mill as raw materials, and the effects of the ultra-fine treatment mechanism on the compaction and sintering behavior of SiC ceramics were investigated. The results showed that the compacts had higher density and microstructure homogeneity when the sintering temperature of the compact was decreased; and that the surface microstructure, densification and mechanical properties of the sintered body could be ameliorated obviously.展开更多
[Objective] This study aimed to further explore the relationship between tea and health. [Method] Different experimental groups were designed to preliminarily investigate the effects of ＂Plateau Bright Pearl＂ commix...[Objective] This study aimed to further explore the relationship between tea and health. [Method] Different experimental groups were designed to preliminarily investigate the effects of ＂Plateau Bright Pearl＂ commixed green tea on blood pressure, myocardial ultrastructure and level of plasma angiotensin Ⅱ （Ang Ⅱ） in spontaneous hypertensive rats. [Result] The results showed that ＂Plateau Bright Pearl＂ commixed green tea could significantly decrease blood pressure and level of plasma angiotensin Ⅱ （ang Ⅱ） in spontaneous hypertensive rats and improve ultrastructures of left ventricular mitochondrion and myofibrillae. [Conclusion] ＂Plateau Bright Pearl＂ commixed green tea has many physiological health functions including losing weight, protecting the heart and lowering blood pressure.展开更多
OBJECTIVE: To detect the feasibility and theoretic basis for treatment with hyperbaric oxygenation (HBO) in chronic hepatitis and to compare the changes in hepatic function, immunity, pathologic morphology, ultrastruc...OBJECTIVE: To detect the feasibility and theoretic basis for treatment with hyperbaric oxygenation (HBO) in chronic hepatitis and to compare the changes in hepatic function, immunity, pathologic morphology, ultrastructure and HBV in hepatic tissues before and after treatment. METHODS: Sixty cases of chronic hepatitis were randomly selected and divided into two groups: the experiment (n = 30) and control groups (n = 30). Patients in the experimental group were treated with HBO for 6 courses. Patients in the control group were treated for 60 days with the usual drugs used in the clinic. The function and bloodstream graph of liver were examined and liver biopsies were made before and after treatments. Routine paraffin sections were stained with HE and observed under the light microscope. Ultra thin slides from paraformaldehyde and glutaraldehyde fixed liver tissue were stained with lead citrate and observed with the transmission electric microscope. HBsAg and HBcAg in liver of the experimental group were detected with ABC immunohistochemistry method before and after treatment. RESULTS: For the experimental group, ALT, SB, gamma-GT, AKP, IgG, and IgM in blood and the degeneration and necrosis of hepatocytes were remarkably decreased (P 0.05), and the expression of HBsAg and HBcAg in liver was not weakened (P展开更多
Objective： To establish the animal model of the compressed lumbar nerve and investigate the effect of acupuncture to the ultra-micro structure of the injured rat lumbar nerve and inflammatory medium. Method： Separat...Objective： To establish the animal model of the compressed lumbar nerve and investigate the effect of acupuncture to the ultra-micro structure of the injured rat lumbar nerve and inflammatory medium. Method： Separate the laboratory rats into Group A （model group, n= 45） and Group B（model ＋ electroacupuncture group, n = 45）. observe injured lumbar nerve tissue with optic microscope and electron microscope and measure the content of PGE2 and 5-HT. Results： Hyperemia around the nerve tissue, edema and nerve root demyelination of electroacupuncture 15 day （Group B） is less than model group 15 day （Group A）. The structure of Schwann cell is normal. Demyelination of electroacupuncture 30 day group （Group B） becomes slight and the nerve edema alleviates. In the Group B, contents of PGE2. and 5-HT after electroacupuncture obviously decrease compared to the Group A. Conclusion： Electroacupuncture can alleviates inflammatory reaction around the injured lumbar nerve and improve the ultra-micro structure of lumbar nerve root.展开更多
Graphene emerges as an ideal material for constructing high-performance strain sensors,due to its superior mechanical property and high conductivity.However,in the process of assembling graphene into macroscopic mater...Graphene emerges as an ideal material for constructing high-performance strain sensors,due to its superior mechanical property and high conductivity.However,in the process of assembling graphene into macroscopic materials,its conductivity decreases significantly.Also,tedious fabrication process hinders the application of graphene-based strain sensors.In this work,we report a freestanding graphene assembled film(GAF)with high conductivity((2.32±0.08)×105 S m-1).For the sensitive materials of strain sensors,it is higher than most of reported carbon nanotube and graphene materials.These advantages enable the GAF to be an ultra-low power consumption strain sensor for detecting airflow and vocal vibrations.The resistance of the GAF remains unchanged with increasing temperature(20-100℃),exhibiting a good thermal stability.Also,the GAF can be used as a strain sensor directly without any flexible substrates,which greatly simplifies the fabrication process in comparison with most reported strain sensors.Additionally,the GAF used as a pressure sensor with only^4.7μW power is investigated.This work provides a new direction for the preparation of advanced sensors with ultra-low power consumption,and the development of flexible and energy-saving electronic devices.展开更多
文摘The ultrastructures of the root protophleom sieve element at different developmental stages of Arabidopsis thaliana L. were investigated using the technique of high pressure freezing and freeze substitution fixing specimen. The results show that in the development of the sieve elements, the nuclei undergo typical characteristics of the programmed cell death (PCD): the nuclear envelopes form emboli, the chromatin condenses and aggregates towards the nuclear envelope, which degrades and fully disappears later. Before the nucleus degradation, neither the nuclear envelope undulation, nucleus lobe nor marked dilation (or bleb) of perinuclear space could be observed. In the cytoplasm of the mature sieve element, there are starch-like granules separately sheathed with a layer of membrane and usually with mitochondria around. These gnanules seem to provide substrates to mitochondria in their function. Small vacuoles originate from endoplasmic reticulum (ER), and no bigger vacuole was found.
文摘The ultrastructure of the vegetative cells of Nostoc flagelliforme Born. et Flah. was investigated with high pressure freezing and freeze substitution technique and compared with the results obtained by using conventional preparation methods. During the processes of chemical fixation, dehydration and embedding, the cell structures might be more artificially modified than that obtained from high pressure freezing and freeze substitution. With the present method, the sheath of N. flagelliforme could be well penetrated and no extra big space could exist between the cell and the sheath. The cell protoplasm rarely shrinked. Some fine structures of cell inclusions and unit membranes became visualized. Many bacteria were harbored in the sheath. In addition, the presence of big vacuoles in the cell of N. flagelliforme as well as the presence of bacteria in the sheath shown in the present preparation for cyanobacteria has not been described so far in the literature.
文摘Silicon carbide ceramics were prepared with SiC powder treated by the fluidized bed opposed jet mill as raw materials, and the effects of the ultra-fine treatment mechanism on the compaction and sintering behavior of SiC ceramics were investigated. The results showed that the compacts had higher density and microstructure homogeneity when the sintering temperature of the compact was decreased; and that the surface microstructure, densification and mechanical properties of the sintered body could be ameliorated obviously.
基金Supported by Major Special Science and Technology Project of Guizhou Province "Key Technology Research and Demonstration of Tea Industry in Guizhou" [(2008) 6015]Project of Guizhou Provincial Department of Science and Technology "Core Technology Research and New Product Development of 'Plateau Bright Pearl' Antihypertensive Health Tea" [(2010) 4002]~~
文摘[Objective] This study aimed to further explore the relationship between tea and health. [Method] Different experimental groups were designed to preliminarily investigate the effects of ＂Plateau Bright Pearl＂ commixed green tea on blood pressure, myocardial ultrastructure and level of plasma angiotensin Ⅱ （Ang Ⅱ） in spontaneous hypertensive rats. [Result] The results showed that ＂Plateau Bright Pearl＂ commixed green tea could significantly decrease blood pressure and level of plasma angiotensin Ⅱ （ang Ⅱ） in spontaneous hypertensive rats and improve ultrastructures of left ventricular mitochondrion and myofibrillae. [Conclusion] ＂Plateau Bright Pearl＂ commixed green tea has many physiological health functions including losing weight, protecting the heart and lowering blood pressure.
文摘OBJECTIVE: To detect the feasibility and theoretic basis for treatment with hyperbaric oxygenation (HBO) in chronic hepatitis and to compare the changes in hepatic function, immunity, pathologic morphology, ultrastructure and HBV in hepatic tissues before and after treatment. METHODS: Sixty cases of chronic hepatitis were randomly selected and divided into two groups: the experiment (n = 30) and control groups (n = 30). Patients in the experimental group were treated with HBO for 6 courses. Patients in the control group were treated for 60 days with the usual drugs used in the clinic. The function and bloodstream graph of liver were examined and liver biopsies were made before and after treatments. Routine paraffin sections were stained with HE and observed under the light microscope. Ultra thin slides from paraformaldehyde and glutaraldehyde fixed liver tissue were stained with lead citrate and observed with the transmission electric microscope. HBsAg and HBcAg in liver of the experimental group were detected with ABC immunohistochemistry method before and after treatment. RESULTS: For the experimental group, ALT, SB, gamma-GT, AKP, IgG, and IgM in blood and the degeneration and necrosis of hepatocytes were remarkably decreased (P 0.05), and the expression of HBsAg and HBcAg in liver was not weakened (P
文摘Objective： To establish the animal model of the compressed lumbar nerve and investigate the effect of acupuncture to the ultra-micro structure of the injured rat lumbar nerve and inflammatory medium. Method： Separate the laboratory rats into Group A （model group, n= 45） and Group B（model ＋ electroacupuncture group, n = 45）. observe injured lumbar nerve tissue with optic microscope and electron microscope and measure the content of PGE2 and 5-HT. Results： Hyperemia around the nerve tissue, edema and nerve root demyelination of electroacupuncture 15 day （Group B） is less than model group 15 day （Group A）. The structure of Schwann cell is normal. Demyelination of electroacupuncture 30 day group （Group B） becomes slight and the nerve edema alleviates. In the Group B, contents of PGE2. and 5-HT after electroacupuncture obviously decrease compared to the Group A. Conclusion： Electroacupuncture can alleviates inflammatory reaction around the injured lumbar nerve and improve the ultra-micro structure of lumbar nerve root.
基金the National Natural Science Foundation of China(51701146,51672204)the Fundamental Research Funds for the Central Universities(WUT:2017IB015)Foundation of National Key Laboratory on Electromagnetic Environment Effects(614220504030617)。
文摘Graphene emerges as an ideal material for constructing high-performance strain sensors,due to its superior mechanical property and high conductivity.However,in the process of assembling graphene into macroscopic materials,its conductivity decreases significantly.Also,tedious fabrication process hinders the application of graphene-based strain sensors.In this work,we report a freestanding graphene assembled film(GAF)with high conductivity((2.32±0.08)×105 S m-1).For the sensitive materials of strain sensors,it is higher than most of reported carbon nanotube and graphene materials.These advantages enable the GAF to be an ultra-low power consumption strain sensor for detecting airflow and vocal vibrations.The resistance of the GAF remains unchanged with increasing temperature(20-100℃),exhibiting a good thermal stability.Also,the GAF can be used as a strain sensor directly without any flexible substrates,which greatly simplifies the fabrication process in comparison with most reported strain sensors.Additionally,the GAF used as a pressure sensor with only^4.7μW power is investigated.This work provides a new direction for the preparation of advanced sensors with ultra-low power consumption,and the development of flexible and energy-saving electronic devices.
