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This paper focuses on the main problems of unstable neutron yield and continuous decrease in neutron yield when using static water-cooled target in the D-D neutron generator. A multifunctional compact rotating target device was developed, which adopted an integrated design and was compact in structure and small in size, equipped with functions such as high-speed rotation and water-cooled of target body, visual monitoring of target point, real-time measurement of target surface temperature, and real-time monitoring of neutron yield. This paper introduced the performance parameters of several major high current neutron generators rotating targets in the world, and elaborated on the advantages of rotating targets compared to traditional static targets. The main structure and functional design of the device were introduced. The main structure of the target was composed of a vacuum target chamber, target plates, beam pipes, circulating cooling water pipes, accompanying particle pipes, target monitoring pipes, stepper motors, and corresponding seals. The functions and structural components of each device were elaborated in detail. In order to study the influence of the structure of the rotating target device on neutron scattering, the energy spectrum distribution of source neutron at various angles in space was simulated by using TARGET software. The energy spectrum data was input into the MCNP data card, and 40 point detectors were set up, with 0°-360° distributed at a distance of 1 m from the target surface. The influence of target structure on neutron scattering was calculated using MCNP simulation. The result of simulation data shows that the target structure broadens the neutron spectrum peak by 0-0.057 7 MeV, and the relative angular yield of scattered neutrons at various angles accounts for 10.53%-26.75%. The influencing factors of neutron scattering effects at several key angles based on energy spectrum curves were analyzed. The vacuum degree, target surface temperature load, and neutron yield stability of the rotating target device were tested. First of all, the average energy of a 300 keV deuterium particle beam in a target thickness of 1 mg/cm2 deuterium titanium target was theoretically calculated. The source neutron flux was calculated using the average energy, and then the device was installed on a neutron generator at Chinese Institute of Atomic Energy to conduct preliminary tests on various performance. The test results show that the vacuum degree of the rotating target remains stable at around 3×10−5 Pa for a long time. Compared with static targets, rotating target improves neutron yield stability by one order of magnitude, and the maximum temperature of the target decreases by 13 ℃. And the cooling effect of the rotating target device was analyzed under different rotational speeds. The results show that as the rotational speed increases, the cooling effect gradually improves. Therefore, the rotating target device designed in this paper basically achieves the expected function, effectively solving the problem of continuous decrease in neutron yield, and the functional test results are normal with low neutron scattering effect. Finally, this paper also analyzes the problems in the simulation calculation results and measurement results, and proposes improvement and optimization plans.

The deformation evolution of reservoir landslides of ten lags behind the variation in the reservoir water level during the operation of the Three Gorges Project, showing a deformation hysteresis effect, and the hysteresis effect is different with the difference in the permeability coefficient and fluctuation rate of reservoir water. Taking the Baijiabao landslide in the Three Gorges Reservoir area as an example, the variation law of the deformation lag time under different permeability coefficients k and reservoir water level decline rates v is studied by field investigation, monitoring data analysis and numerical simulation. The results show that when the permeability coefficient of the landslide is constant, the higher the decreasing rate of reservoir water level is, the more obvious the groundwater lag. When the reservoir water level drops at a certain rate, the greater the permeability coefficient of the sliding body is, the faster the groundwater drop.When the permeability coefficient of the sliding body is 0.85 m/d, the higher the rate of reservoir water level decline is, the shorter the deformation lag time of the landslide.The corresponding lag time is 3.74-9 d under different decline rates of the reservoir water level.When 0.47 < v/k < 1.18, 0.24 < relative deformation lag time < 1; when 1.18 < v/k < 2.38, 0 < relative deformation lag time < 0.24. When the reservoir water level decline rate is constant, the larger the landslide permeability coefficient is, the shorter the landslide deformation lag time is. Under different reservoir water level decline rates, the change rule of the relative deformation lag time with increasing v/k value is roughly the same, v=1.8 m/d, and the corresponding lag time of different permeability coefficients is 1.7-8 d. When 0.52 < v/k < 0.84, 0 < relative deformation lag time < 0.16; when 0.84 < v/k < 2.12, 0.16 < relative deformation lag time < 0.43; when 2.12 < v/k < 9, 0.43 < relative deformation lag time < 1. The research results have strong application value for the prediction and warning of reservoir landslides.

High-speed landslides have the characteristics of fast movement speed and rapid spread. Therefore, it is necessary to study the whole movement process of landslides starting, accelerating and resting.Based on the mechanical properties of the sliding surface, the sliding surface is divided into an elastic medium region and a strain weakening region, and a two-dimensional mechanical model of a high-speed landslide is constructed. The energy calculation formulas of landslide initiation and landslide movement processes are proposed. Taking the Qianjiangping landslide as an example, the initiation speed of the landslide is 2.35 m/s by using the energy calculation formula of landslide initiation. According to the sliding surface morphology, the landslide movement trajectory can be divided into a fast acceleration stage, a steady acceleration stage, a steady deceleration stage, and a sharp deceleration stage. The maximum speed is 16.8 m/s during analysing the motion process. The elevation plane of the landslide front is taken as the potential energy datum plane to analyze the variation in different energy and total energy ratios. In the four movement stages of the landslide, the proportions of kinetic energy were 9.1%, 25.6%, 15.1%, and 0%; the proportions of friction loss energy were 5.5%, 58.8%, 81.7%, and 95.5%; the proportions of potential energy were 85.2%, 14.2%, 0%, and 0%;and the proportions of other resistance energy consumption were 0.2%, 1.4%, 3.2%, and 4.5%. The research conclusions are of great significance to the hazard mechanism and risk analysis of high-speed landslides.

Objective To analyze the relationship between preoperative enhanced MRI manifestation and recurrent time of recurrent glioblastoma, and to explore the predictive value of imaging signs for recurrence time. Methods A total of 36 patients with pathologically confirmed glioblastoma were collected from February 2012 to April 2017. All patients underwent preoperative and postoperative T 1 WI and enhanced MRI scans, and enhanced cross ⁃ sections and sagittal or coronary scans were performed. Manually measure the volume of the lesion⁃enhanced and non⁃enhanced necrotic areas on the enhanced MRI image. The totality was divided into 2 groups according to the percentage of necrosis that accounts for the entire tumor volume. Necrosis in group A accounts for > 50% of the total tumor volume, and necrosis in group B accounts for < 50% of the total tumor volume. Analyze the enhanced MRI features before surgery, the time of first recurrence, MRI manifestations and overall survival (OS). Results The recurrence time in group A was significantly shorter than that in group B [(6.00 ± 0.99) months vs. (9.00 ± 1.49) months, P = 0.049]. Necrotic⁃based glioblastomas recurred faster. When stratifying patients in group A and group B based on clinical characteristics, the recurrence time of patients in group A was still significantly shorter than that in group B in the group of age < 65 years old and receiving radiotherapy and chemotherapy [6 (3, 8) months vs. 9 (6, 13) months, 6 (6, 10) months vs. 12 (3, 24) months; P < 0.05, for all]. Conclusions Preoperative enhanced MRI findings have predictive value for postoperative recurrence in patients with glioblastoma who are younger than 65 years old and receive radiotherapy and chemotherapy. DOI：10.3969/j.issn.1672⁃6731.2019.12.008

Background Subependymal giant cell astrocytoma (SEGA) is a rare kind of central nervous system tumor typically occurring in children or adolescents under the age of 20. The tumor commonly arises in the region of the foramen of Monro. Most SEGA patients present distinctive histopathological and immunohistochemical characteristics. Methods The clinical features, histopathological findings and immunohistochemical staining in one case of SEGA were analyzed, and the diagnosis and differential diagnosis of this disease with literature review were studied. Results A 13-year-old female patient presented dizziness, headache and vomiting. Cranial MRI examination showed abnormal signals in the left lateral ventricle near the foramen of Monro, and exhibited heterogeneous enhancement after contrast. Histologically, the tumor was composed of clustering of fibrillated spindle cells and giant cells with abundant cytoplasm, and they were mixed. Glassy hyaline cytoplasm and eccentric vesicular nuclei with prominent nucleoli were frequently seen in the giant tumor cells. Some of the giant cells appeared to resemble gemistocytic astrocytes or ganglion cells. Considerable nuclear pleomorphism and multinuclear cells were frequently seen. There was no significant microvascular proliferation or necrosis. Immunohistochemical findings showed diffuse and strong positivity in tumor cells for vimentin (Vim), and partial positivity for S-100 protein (S-100), epithelial membrane antigen (EMA) and glial fibrillary acidic protein (GFAP). A few giant tumor cells were positive for synaptophysin (Syn), but negative for neurofilament protein (NF), neuronal nuclei (NeuN) and cytokeratin (CK). Ki-67 labeling index was very low (< 1%). Conclusions SEGA is a benign central nervous system tumor (WHOⅠ). It has distinctive clinical and histopathological features, and should be differentiated from gemistocytic astrocytoma, ependymoma, gangliocytoma and giant cell glioblastoma. doi: 10.3969/j.issn.1672-6731.2014.11.014

Objective To explore the clinicopathological and immunohistochemical features of intracranial malignant melanoma metastasis. Methods Analysed the clinical features, histopathologic findings and immunohistochemical staining in 2 lesions of one case with multiple intracranial malignant melanoma metastasis, and studied the diagnosis and differentiation of this disease with literature review. Results The pathologic findings of the 2 lesions located in the right frontal lobe and right temporal lobe were dissimilar to each other. The previous lesion presented as old hematoma was composed of a few papilliform structures within sheet of bleeding with capillaries and fibrous tissue surrounded by epithelioid cells. The following lesion in the right temporal lobe was predominantly composed of spindle cells with rich cytoplasm, marked nuclear atypia and eosinophile nucleoli that arranged in cell nests and fascicles. Brisk mitotic activity and necrosis could also be seen in the tumor. Left inguinal lymph nodes metastasis notable with thick melan in granule inside and outside the tumor cells was found, and the tumor cells were similar to those of the lesion in the right temporal lobe. Immunohistochemistry with antibodies for S-100 protein (S-100), HMB45, Melan-A, vimentin (Vim), epithelial membrane antigen (EMA), cytokeratin (CK), glial fibrillary acidic protein (GFAP), synaptophysin (Syn) and neurofilament protein (NF) was performed. A diffuse reactivity of the neoplastic cells for S-100 protein, HMB45, Melan-A, vimentin was observed. EMA presented partially positive. All other markers were negative. Conclusion The histopathologic findings of intracranial malignant melanoma metastasis are quite complicated. Although the clinical case history and neuroimaging are important, the diagnosis of the disease is dependent on immunohistochemical staining method. It must be differentiated from metastatic carcinomas, meningeal tumors, malignant lymphomas and other melanocytic neoplasms. DOI:10.3969/j.issn.1672-6731.2011.04.018

Quercetin and its glycosides are important flavonols in traditional herbal drugs and plant-derived food, and they have diverse hiological activities such as antioxidant, anticarcinogenic, anti-inflammatory, hypoglycemic and hypolipidemic activities. Numerous studies have demonstrated that quercetin and its glycosides were effective in the prevention and treatment of non-infectious chronic disease such as diabetes, obesity, and hyperlipidemia. They can regulate glucose and lipid metaholism through different mechanisms. They can decrease blood glucose via protecting pancreatic/p cells or/and improving insulin sensitivity. Also, they have lipid-lowering effects, which may be the result of regulation of lipid catabolism or/and anabolism. Their distributions, as well as the hypoglycemic and hypolipidemic effects are reviewed in this paper. In addition, further bioactivities as well as their dose-activity relationship, structure-activity relationship, bioavailability, and future clinical application of quercetin and its glycosides are discussed and proposed.

Using tomato (Solanum lycopersicum L. cv. Micro-Tom) leaf as material, a simple and rapid DNA preparation protocol was established. This method required only 2-20 mm2 leaf with only one extraction solution and involved one pipetation and one centrifugation each. No precipitation was required. The suitable volume of prepared DNA solution, as PCR template, for real-time quantitative PCR was determined to be 0.10.2 μL in 12.5 μL final reaction volume. The excessive template DNA solution was confirmed to reduce PCR efficiency and even can result in PCR failure. This technique for rapid preparation of DNA and a compatible real-time quantitative PCR were successfully applied in transgene detection of tomato plants.

Micro-Tom is a miniature dwarf tomato, which can grow at a high density, has a short life cycle, and can be transformed efficiently. As a result, it became a new model plant for functional genomics study. The origin and biological characteristics of Micro-Tom were summarized. Recent advances in the mechanisms involved in the miniature dwarf trait, as well as the application of Micro-Tom in plant functional genomics study and the improved genetic transformation systems were reviewed.

Harvested fruits of three Chinese bayberry (Myrica rubra Sieb. & Zucc.) varieties, i.e. "Biqi", "Dongkui" and "Zaodamei" which were divided into three maturities (designated as "Immature", "Mature" and "Ripe") according to fruit colour, were investigated for the changes in climacteric pattern and quality at 20 degrees C. Respiration rate and ethylene production rate were underwent 3 h during 48 h storage. Our result showed that both Immature and Mature fruits underwent rises in respiration and ethylene production rate of a climacteric rise, but no such peak was observed in Ripe fruit (Fig.1 and 2). Total soluble solids (TSS) contents increased with maturity and decreased over the 48 h at 20 degrees C (Fig.3); titratable acidity (TA) decreased with the maturity and throughout 48 h storage period (Fig.4). In "Biqi" Chinese bayberry fruit, PAL activities increased in Immature and Mature fruit, but, it decreased in Ripe fruit during the storage period; the change in Cy-3-Glu with fruit ripening was consistent with PAL activities (Table 1); there was significant positive correlation between CIRG (Color Index for Red Grape) values and Cy-3-Glu content (r=0.96**). This study provides important information on the postharvest behaviour of Chinese bayberry fruit, and our result shows that it is climacteric fruit.

According to the conserved amino acid sequence from ethylene receptors in other plants, a pair of degenerate primers was designed and a 657-bp cDNA fragment encoding an ethylene receptor fruit was obtained by RT-PCR from ripening kiwifruit (Actinidia deliciosa cv. Bruno) (Fig. 1). The cDNA fragment encoding 219 amino acids was named Ad-ETR1, and its sequences shared high similarity at both nucleotide and polypeptide level with the sequences from the plants of Arabidopsis, tomato, persimmon, avocado, citrus and peach (Fig. 2, Table 1). Northern blot analysis indicated that the levels of Ad-ETR1 mRNA increased during kiwifruit ripening and reached peak at 144 h after treatment, then dropped immediately. The expression of Ad-ETR1 could be induced by ethylene treatment, while acetylsalicylic acid (ASA) treatment inhibited its expression (Fig. 4). In consistency with the changes of Ad-ETR1 mRNA, ethylene or ASA treatment had marked effects on the kiwifruit ethylene production and fruit softening (Fig. 3). The significance of these results was discussed.

Sugars accumulation and fructokinase activity during satsuma mandarin fruit development in relation to the effect of extra nitrogenous fertilizer on the activity and expression of fructokinase were studied. The results exhibited that fructokinase activity in the tissues of edible and peel decreased during fruit development, which coincided with the accumulation of sugars, while the contents of sucrose and glucose decreased, and the activity of the enzyme increased in peel tissues of ripened fruit. After fertilizing with extra urea, the ratios of sucrose and fructose decreased in ripe fruit, while that of glucose increased compared to the control. The activity of fructokinase presented on a protein basis increased in treated fruit. Northern analysis confirmed that extra nitrogenous fertilizer enhanced the expression of Cufrk1 at the late stage of fruit development, but had no effect on Cufrk2. The results suggest that the two different genes of citrus FRK may play distinct roles in sink metabolism and Cufrk1-encoded fructokinase protein could be induced by fertilization with extra nitrogen.

It is a difficult problem to isolate high quality DNA from plants containing a high contents of polyphenolics and polysaccharose, such as Actinidia plant. The protocol described in this paper is a modified CTAB (hexadecyltrimethylammonium bromide) method. High quality genomic DNA can be isolated from Actinidia plant using the improved method. The DNA is good enough for Southern blot and other uses in DNA research. The protocol is also efficient for quick and macro-DNA extraction.

Kiwifruit (Actinidia deliciosa cv. Bruno) was used to investigate starch and sugar metabolism and the mechanisms of regulation by acetylsalicylic acid (AsA 1.0 mmol/L, pH 3.5), low temperature (0 degrees C) and ethylene (100 microL/L) treatments. There was an increase in amylase activity at the initial stage followed by dramatical decrease in starch content and a rapid increase in hexose content at the rapid stage of fruit ripening and softening, which was associated with an increase in SPS activity, a decrease in acid invertase activity, and the accumulation of sucrose. AsA and low temperature treatments inhibited the amylase activity, slowed down the hydrolysis of starch and the accumulation of hexoses, suppressed the rise of SPS activity and the decline of acid invertase activity in the ripening fruit. The accumulation of sucrose was delayed by AsA and low temperature treatments. However, ethylene application induced amylase activity, accelerated starch hydrolysis, and raised the hexose content. The SPS activity also increased and the sucrose accumulated in the presence of ethylene. It is suggested that the SPS may play a key role in sugar metabolism of postharvest kiwifruit, and it could be activated by hexose and feedback-inhibited by sucrose. AsA, low temperature and ethylene treatments regulate sugar metabolism probably through influencing the SPS activity.

Programmed cell death (PCD) is an active way for plant cells marching to death, which plays an important role in plant development and stress responses. Cytological, biochemical, molecular and physiological methods for measuring plant PCD were reviewed. Application of flow cytometer to plant PCD research was also covered.