Search

To exploit the geothermal energy from low penetration rocks at a depth of 3–10 kilometers below the ground surface, an artificial geothermal system usually must be built. Thermal and chemical stimulation can be used as auxiliary means of hydraulic fracturing for artificial geothermal reservoir reconstruction, which is conducive to reducing the risk of earthquakes. However, thermal shock and chemical corrosion can also cause changes in physical parameters such as density, porosity, longitudinal wave velocity, and the thermal conductivity of high-temperature rock mass, which brings great uncertainty to the service life of a geothermal system. To study the evolution of the physical properties and thermal conductivity of thermal shock granite under chemical modification, long-term acid and neutral solution immersion tests were performed on granite specimens subjected to thermal shock at temperatures ranging from 25 ℃ to 600 ℃. Using ultrasonic testing, nuclear magnetic resonance, thermal constant testing, and scanning electron microscopy, the evolution of the physical parameters of thermal−chemical modified specimens with thermal shock temperature was quantitatively characterized, the internal correlation among physical parameters was established, and the microscopic mechanism of the change in physical properties was revealed. The results show that with increasing thermal shock temperature, the volume of thermal–chemical− modified specimens increases gradually, the mass and density decrease gradually, the longitudinal wave velocity decreases linearly, the porosity increases by a power function, and the thermal conductivity and thermal diffusivity decrease exponentially and linearly, respectively. At the same thermal shock temperature, the volume growth fraction, longitudinal wave velocity, and thermal conductivity of the modified specimens are in the order of non-immersion > water immersion > acid immersion, while the mass loss fraction and porosity are in the order of acid immersion > water immersion > non-immersion. The increase in porosity and the deterioration of thermal conductivity are accompanied by a decrease in longitudinal wave velocity, so the porosity and thermal conductivity can be estimated by measuring the longitudinal wave velocity. The pore structure of the modified specimens is more sensitive to temperatures in the range of 150–450 ℃, while the solid particle skeleton is more sensitive to temperatures above 450 ℃, and the deterioration of the particle skeleton will further cause the transformation of the pore structure. The thermal-chemical modification results in the development of pore structure and phase transformation, which are the fundamental reasons for the changes in the physical properties of granite. High-temperature thermal shock plays a leading role in the process of thermal-chemical modification, while chemical corrosion plays an auxiliary role. At the selected test temperature levels, 300 ℃ can be considered the temperature threshold for severe thermal shock.

Girth weld is an indispensable part of long-distance pipelines. Girth weld failure is caused by the interaction of load, defects, local fracture toughness, strength matching, weld geometry and residual stress, and the welding for high steel grade pipelines is particularly difficult which increases the failure possibility of girth welds. In this case, the load, defect and strength matching characteristics of girth weld were analyzed, the strain concentration mechanism of low matching girth welds or softening girth welds in heat affected zone was revealed, and four failure modes including brittle fracture, net section collapse before yield, net section collapse after yield and base metal necking of girth weld were explained. Based on the comparison of the applicability of girth weld safety assessment in GB/T 19624—2019、BS 7910-2015、API 579-1/ASME FFS-1-2016、API 1104-2013 and other domestic and foreign standards, the strain-based girth weld safety assessment method was proposed, and the influence of crack size, strength matching coefficient and other factors on girth weld crack driving force was discussed. The research demonstrates that the load or displacement of the girth weld should be the premise of the safety assessment, and improving the strain capacity of the girth weld can enhance the adaptability of high grade steel pipelines to adverse geological conditions. It is suggested to carry out the research on the initiation and growth mechanism of the girth weld crack defects, develop the strain-based fracture theory, optimize the strength matching of the girth weld, and quantify the relation between the strain capacity of the girth weld and the geometric and mechanical performance parameters of the weld.

Stress intensity factors (SIF) and crack mouth opening displacements (CMOD) for three-point bending beams with arbitrary span-to-width ratios (S/W) were calculated by using the Wu-Carlsson analytical weight function for edge-cracked finite-width plate and the analytical solution of un-cracked stress by Filon. Based on the analytical weight function and tabulated SIF and CMOD data for power-law crack-line stresses, SIF and CMOD for general polynomial crack face loadings could be rapidly determined by simple arithmetic. The results obtained for several span-to-width ratios determined by using fundamentally different methods are in excellent agreement with those in literature. A brief discussion is made for calculating cohesive fracture toughness by analytical weight function method. The present study provides a high efficient and accurate method for fracture mechanics analysis of the three-point bending beam with arbitrary span-to-width ratio.

Aiming at the lack of effective load analysis method, a load analysis method of cycloidal pin wheel based on minimum deformation energy was proposed. By introducing the minimum deformation energy, the actual number of simultaneous meshing teeth was determined, and the real load characteristics in line with the engineering practice were obtained. Through finite element simulation and measurement experiments, the correctness and effectiveness of the theoretical analysis method of minimum deformation energy introduced were verified. The results show that the predicted maximum possible number of teeth, the results calculated by the principle of minimum energy and the results of finite element analysis are all 16 teeth. The transmission error curves of theoretical calculation, actual measurement and simulation analysis show a relatively consistent parabolic trend, and the maximum fluctuation ranges are 3. 83', 3. 66' and 3. 70' respectively. [ABSTRACT FROM AUTHOR]

Because the traditional image segmentation algorithm had the defects of poor noise resistance and low iteration speed, in order to improve the quality of image segmentation, a whale optimization algorithm (WOA) with reverse learning strategy and a two-dimensional maximum entropy image segmentation method were proposed, and the WOA algorithm was optimized by nonlinear adjustment combining Sobol sequence, adaptive weight coefficient and convergence factor. The optimal threshold of the target image was obtained and segmented. Compared with the original WOA algorithm in the test function, the improved algorithm has better convergence and faster convergence speed. When the improved algorithm is applied to the lawn background, the peak signal-to-noise ratio value of the segmented image is increased by 5. 2% and 3. 5% respectively compared with the other two contrast algorithms, and increased by 3. 6% and 2. 2% respectively under the sky background. The improved algorithm can improve the quality of the segmented image, reflecting the advantages of the algorithm. [ABSTRACT FROM AUTHOR]

ObjectiveTo analyze the epidemic characteristics and trend of mosquito vectors related to Japanese encephalitis （JE） in Mengla County， and to provide scientific evidence for JE prevention and control.MethodsThe JE related mosquito vector monitoring data in Mengla County from 2016 to 2020 were collected and subjected to further statistical analysis.ResultsA total of 1 689 mosquitoes were captured at the JE mosquito vector monitoring sites in Mengla County， 36.3% of which were captured in 2020 and 13.3% in 2017. The density of Culex tritaeniorhynchus was the highest （3.04 per lamp per day）， and that of Anopheles sinensis was the lowest （1.03 per lamp per day）. The distribution of mosquito species showed significant difference in the same year. The mosquito density in pig house was 12.93 per lamp∙day， and that in human house was 4.67 per lamp∙day. The mosquito density of different mosquito species in pig house was higher than that in human house. There was no significant difference in the site distribution of Anopheles sinensis， but there were significant differences in the site distribution of Culex tritaeniorhynchus， Culex pipiens quinquefasciatus and other mosquito species. The mosquito density peaked in May （12.78 per lamp per day） and July （10.28 per lamp per day）. The temporal distribution showed that the vector density decreased gradually from May to October， however， the species population structure also varied significantly， and the trends of each mosquito species also varied greatly. In Mengla， Culex tritaeniorhynchus peaked in May.ConclusionThe JE epidemic situation in Mengla County is still severe. It is recommended to strengthen prevention and control in the peak season of mosquito activities， such as actively carrying out patriotic health campaigns， and effective public education. At the same time， we should also strengthen the JE vaccination for school-age children and the training of medical personnel.

In order to understand whether Pomacea canaliculata exhibits gender differences in cold resistance, the survival rate and supercooling point of both P. canaliculata females and males were investigated at low temperature. The changes in physiological and biochemical indices in the body of P. canaliculata before and after the winter were also examined. The results showed that the mean supercooling point of females was -6.83 °C, which was significantly lower than that of the males (-6.26 °C). With the arrival of winter, the amounts of bound water, glycerol, lipid and glycogen of P. canaliculata increased, while the amount of free water decreased. These indices except glycerol showed significant differences between males and females. More than 90% non-acclimated snails could survive at the temperature of 10 °C for 7 days. The survival rate of snails exhibited significant differences in sex and shell height after being transferred at 5 °C for 7 days. In addition, more females were recorded during field investigation. Based on these results, we concluded that the females had higher cold tolerance than the males. This finding would provide some references for further investigation of ecological adaptation, natural sex ratio and cold tolerance mechanisms of P. canaliculata. [ABSTRACT FROM AUTHOR]

According to the deficiency that space exploration may occur when the security protocols of colored Petri nets are analyzed, the paper proposes to construct the knowledge RI that is required by intruders to successfully attack the security protocols and the knowledge KI that can be obtained by intruders.And the improved colored Petri net of successful attack functions.The improved colored Petri net is used to analyze Helsinki protocol and TMN protocol.Experiments show that the proposal can simplify the procedure of constructing the Petri net with intruders, and efficiently solve the space exploration problem. [ABSTRACT FROM AUTHOR]

Taking the soils developed from two kinds of parent materials (granite and limestone) under Pinus tabulaeformis forest at the same altitude in Songshan Mountain Nature Reserve of Beijing as test objects, this paper studied the vertical distribution patterns of soil total nitrogen, available phosphorus, and available potassium. The soil developed from granite had the total nitrogen, available phosphorus, and available potassium contents being 1. 61-2. 35 g · kg-1, 5. 84- 10-74 mg · kg-1, and 39. 33-93. 66 mg · kg-1, while that developed from limestone had the total nitrogen, available phosphorus, and available potassium contents being 1. 69 -2. 36 g.kg-1, 4. 45-8. 57 mg · kg-1, and 60. 66-124. 00 mg · kg-1, respectively. The total nitrogen, available phosphorus, and available potassium contents in the two soils were the highest in 0-10 cm layer, decreased with increasing depth, and had significant differences between different layers, showing that the soil total nitrogen, available phosphorus, and available potassium had a strong tendency to accumulate in surface layer. Such a tendency was more obvious for the soil developed from limestone. The paired t-test for the two soils indicated that the total nitrogen content in different layers had no significant difference, whereas the available phosphorus content in 0-10 cm layer and the available potassium content in 10-20 cm layer differed significantly. [ABSTRACT FROM AUTHOR]

The article presents a research which explores the IFNω3-THYα1 fusion protein of the cat's prokaryotic gene expression.

There are the time related classifiers in both Chinese and Thai word--class. But there are also some differences in word combination and syntactic functions. By comparing the usage of time related classifiers, we can find Chinese time related classifiers are richer and more complicated than those in Thai language. [ABSTRACT FROM AUTHOR]

Traditional reinforcement learning algorithms require lots of online interaction with the environment for training and cannot effectively adapt to changes in the task environment, making them difficult to apply to real-world problems. Offline meta-reinforcement learning provides an effective way to quickly adapt to a new task by using replay datasets of multiple tasks for offline policy learning. Applying offline meta-reinforcement learning to complex tasks will face two challenges. Firstly, reinforcement learning algorithms overestimate the value of state-action pairs not contained in the dataset and thus select non-optimal actions, resulting in poor performance. Secondly, meta-reinforcement learning algorithms need not only to learn the policy but also to have robust and efficient task inference capabilities. To address the above problems, this paper proposes an offline meta-reinfor-cement learning algorithm based on contrastive prediction. To cope with the problem of overestimation of value functions, the proposed algorithm uses behavior cloning to encourage policy to prefer actions included in the dataset. To improve the task inference capability of meta-learning, the proposed algorithm uses recurrent neural networks for task inference on the contextual trajectories of the agents and uses contrastive learning and prediction networks to analyze and distinguish potential structures in different task trajectories. Experimental results show that the agents trained by the proposed algorithm can score more than 25 percentage points when faced with unseen tasks, and it has higher meta-training efficiency and better generalization performance compared with existing methods.

Single aluminide coating has shortcomings such as insufficient resistance to high-temperature oxidation and high-temperature thermal corrosion.The addition of modifying elements can change the structural composition of the aluminide coating.The addition of modifying elements affected the oxidation resistance and thermal corrosion resistance of the coating by affecting the transformation and detachment of the oxide film，as well as the diffusion of aluminum and oxygen elements，and changed the mechanical properties of the coating.In this paper，the studies on the effects of modifying elements on the microstructure，oxidation resistance，thermal corrosion resistance，and mechanical properties of aluminide coatings in recent years were summarized.And the development direction of modified aluminide coating on nickel-base alloy in the future was prospected.

A case of primary pulmonary artery sarcoma (PPAS) complicated with pulmonary embolism and pulmonary tuberculosis is reported. This patient, a 48-year old woman, was diagnosed as pulmonary tuberculosis at the initial stage of the disease, whose condition was improved after anti-tuberculosis treatment, and was finally diagnosed as PPAS combined with pulmonary embolism due to recurrence of the symptoms. PPAS is a very rare malignant tumor originating from the inner or subintima of the pulmonary artery. The clinical manifestations of PPAS have no obvious specificity which can be dyspnea, chest pain, cough, hemoptysis, and so on. Enhanced CT, enhanced MRI, and positron emission computed tomography (PET/CT) is beneficial to the differential diagnosis of PPAS, but definitive diagnosis needs intravascular biopsy or surgical biopsy. Because PPAS often presents as pulmonary embolism, patients with PPAS were often misdiagnosed as pulmonary embolism, resulting in delayed diagnosis and treatment. There are few reports of PPAS presenting as pulmonary embolism complicated with pulmonary tuberculosis at home and abroad, which is also easy to be misdiagnosed. The disease has a high degree of malignancy, which is short of effective treatment at the late stage, with short survival time and poor prognosis. Therefore, attention to the various clinical manifestations of PPAS and early diagnosis and treatment are crucial to the prognosis of PPAS patients.

To systematically evaluate the efficacy and safety of Chinese medicine in the treatment of drug-induced liver injury(DILI). By searching the randomized controlled trials(RCTs) of the Chinese medicine published in CNKI, WanFang, VIP, PubMed, Web of Science, in a time limit from database establishment to May 1, 2020. The bias risk assessment and Meta-analysis were then conducted for the included studies. Seventeen studies were finally included, all of which were RCTs, including 1 407 patients. The experimental group was treated with Chinese herbal medicine decoction or Chinese patent medicine, involving a total of 11 kinds of drugs, and the control group was treated with conventional Western medicine. Meta-analysis results showed that, in terms of treatment effective rate, Yinlan Yigan Granules, Shuganning, Jiangmeiling Capsules, Baidan Shugan Recipe and Sini Shugan Decoction were all superior to Western medicine treatment. In terms of reducing alanine aminotransferase(ALT), Yinlan Yigan Granules, Shuganning, Hugan Jiedu Recipe, Wuzhi Tablets, Wucao Baogan Recipe and Liuwei Wuling Tablets were superior to Western medicine. In terms of reducing aspartate aminotransferase(AST), Shuganning, Hugan Jiedu Recipe, Wucao Baogan Recipe, Liuwei Wuling Tablets and Sini Shugan Decoction were all superior to Western medicine. In terms of reducing total bilirubin(TBiL), Yinlan Yigan Granules, Shuganning, Jiedu Hugan Yin, Wuzhi Tablets, Wucao Baogan Recipe, Baidan Shugan Recipe and Sini Shugan Decoction were all superior to Western medicine treatment. Combined with network Meta-analysis and probability ranking, it can be seen that, Jiangmeiling Capsules, Shuganning, Sini Shugan Decoction and Baidan Shugan Recipe were most likely to be the best drugs to improve the efficiency and reduce ALT, AST, TBiL, respectively, with certain advantages compared to conventional Western medicine treatment. Of the seventeen studies included, eight studies described safety issues, three of which involved the test group, all of which were minor adverse reactions that disappeared after drug withdrawal or symptomatic treatment. However, due to the low quality of the included studies, more high-quality clinical studies are needed for further verification, thus providing more evidence-based medical evidence for Chinese medicine intervention in DILI.

In order to understand whether Pomacea canaliculata exhibits gender differences in cold resistance, the survival rate and supercooling point of both P. canaliculata females and males were investigated at low temperature. The changes in physiological and biochemical indices in the body of P. canaliculata before and after the winter were also examined. The results showed that the mean supercooling point of females was -6.83 degrees C, which was significantly lower than that of the males (-6.26 degrees C). With the arrival of winter, the amounts of bound water, glycerol, lipid and glycogen of P. canaliculata increased, while the amount of free water decreased. These indices except glycerol showed significant differences between males and females. More than 90% non-acclimated snails could survive at the temperature of 10 degrees C for 7 days. The survival rate of snails exhibited significant differences in sex and shell height after being transferred at 5 degrees C for 7 days. In addition, more females were recorded during field investigation. Based on these results, we concluded that the females had higher cold tolerance than the males. This finding would provide some references for further investigation of ecological adaptation, natural sex ratio and cold tolerance mechanisms of P. canaliculata.

Baculovirus gene expression is the most popular method to make target protein in cultured insect cells. To fast determine the generation of recombinant virus in cultured cells, donor plasmid of pFastBacI was modified by introducing egfp cassette. In the modified vector, egfp cassette was under the control of ie1 promoter, and target gene cassette was under the control of polyhedron promoter. To evaluate the convenience of the genetically modified donor plasmid used in eukaryotic expression, ns1 gene from Bombyx mori bidensovirus was ligated into the donor plasmid to generate recombinant plasmid pFastBacI-[P(ie1)-egfp-sv40]-[P(polh)-ns1-sv40]. Then the plasmid was transformed into DH10B competent cells containing Bm-Bacmid vector to produce the final recombinant Bm-Bacmid with the help of transposase. The resulting recombinant Bm-Bacmid was transfected into BmN cells to generate recombinant virus, which was easily and rapidly judged by green fluorescent signal observed in BmN cells. After infection for 96 h, the BmN cells were harvested and the total protein extracted from the infected BmN cells was subjected to Western blotting analysis. The result showed that a specific protein band about 36 kDa was detected, indicating that NS1 protein was successfully expressed in the BmN cells. In conclusion, the expression of NS1 protein with the modified expression system is useful for further research on the function of NS1 protein.

Objective: To establish a highly sensitive fluorometric nanobiosensor for determination of aqueous mercury ions (Hg(2+)) using optimized mercury-specific oligonucleotide (MSO) probes and graphene oxide (GO)., Methods: The nanobiosensor was assembled by attaching the self-designed MSO(1) (5' end labeled with fluorophore carboxyfluorescein (FAM), denoted as FAM-MSO(1)) and MSO(2) to the surface of GO through strong non-covalent bonding forces. Upon the addition of Hg(2+), the formation of the T-Hg(2+)-T configuration desorbed the FAM-MSO(1) and MSO(2) from the surface of GO, resulting in a restoration of the fluorescence of FAM-MSO(1). Using the specific mispairing of T-Hg(2+)-T and the changes in fluorescent signals in solutions, quantitative analysis of Hg(2+) could be performed., Results: The average thickness of the prepared GO sheets was only 1.4 nm. For the Hg(2+) nanobiosensor, the optimum concentrations of FAM-MSO(1) and MSO(2) were both 1 µmol/L, the optimum volume of 0.5 g/L GO was 5 µL, and the limit of detection was 10 pmol/L; it had low cross-reactivity with 10 other kinds of non-specific metal ions; the fluorescence recovery efficiency was up to 65% in the re-determination of Hg(2+) after addition of Na(2)S(2)O(3)., Conclusion: The MSO/GO-based nanobiosensor is convenient to operate, highly sensitive, highly specific, highly accurate, and reusable. It can be applied to determine trace amount of Hg(2+) in aqueous solutions.

Nogo-B is a major family member of the reticulon protein family 4. It is widely expressed in the central nervous system and peripheral tissues, and is mainly located in endoplasmic reticulum and cell membrane. Previous studies have revealed that Nogo-B plays a key role in vascular injury, tissue repair and inflammation process. It also may be critical for apoptosis of tumor cells and central diseases. Further investigation of the molecular characteristics and biological function of Nogo-B might be of great help to understand its role in diverse diseases.

Taking the soils developed from two kinds of parent materials (granite and limestone) under Pinus tabulaeformis forest at the same altitude in Songshan Mountain Nature Reserve of Beijing as test objects, this paper studied the vertical distribution patterns of soil total nitrogen, available phosphorus, and available potassium. The soil developed from granite had the total nitrogen, available phosphorus, and available potassium contents being 1.61-2. 35 g kg-1, 5. 84-10.74 mg kg- 1, and 39.33-93.66 mg kg-1, while that developed from limestone had the total nitrogen, available phosphorus, and available potassium contents being 1. 69 -2. 36 g kg-1, 4.45-8.57 mg . kg-1, and 60.66-124.00 mg kg-1, respectively. The total nitrogen, available phosphorus, and available potassium contents in the two soils were the highest in 0-10 cm layer, decreased with increasing depth, and had significant differences between different layers, showing that the soil total nitrogen, available phosphorus, and available potassium had a strong tendency to accumulate in surface layer. Such a tendency was more obvious for the soil developed from limestone. The paired t-test for the two soils indicated that the total nitrogen content in different layers had no significant difference, whereas the available phosphorus content in 0-10 cm layer and the available potassium content in 10-20 cm layer differed significantly.

Aim: To investigate the effect of co-stimulation of mimic viral infection [polyinosinic: polycytidylic acid, poly(I:C)] and endotoxin (lipopolysaccharide, LPS) on chemotactic factors production of human bronchial epithelial cells and explore its related mechanism., Methods: Human bronchial epithelial cells (16HBE) were challenged by co-stimulation of different concentrations of poly(I:C) and LPS. Some other 16HBE cells, before the co-stimulation of poly(I:C) and LPS, were pretreated with dexamethasone and p38MAPK specific inhibitor (SB203580), respectively. The levels of IL-8/CXCL8 and IP-10/CXCL1 mRNA transcription were detected by RT-PCR after 6 h challenge. The contents of IL-8 and IP-10 proteins were detected by ELISA after 24 h challenge., Results: (1) The mRNA and protein expression of IL-8, not IP-10, increased under 10 μg/mL LPS stimulation compared with control group. The mRNA and protein expressions of both IL-8 and IP-10 were elevated significantly by the co-stimulation of LPS and 0.1 μg/mL poly (I:C) compared with control group and simple LPS groups. (2) The mRNA and protein expressions of IL-8 and IP-10 increased under the challenge of different concentrations of poly(I:C) (0.001, 0.01, 0.1 μg/mL) in a concentration-dependent manner, which showed no change after adding 10 μg/mL LPS. (3) Dexamethasone (1 μmol/L) and SB203580 (20 μmol/L) significantly decreased both the mRNA and protein production of IL-8 and IP-10 induced by co-stimulation of 0.1 μg/mL poly (I:C) and 10 μg/mL LPS compared with the control group and control+DMSO group respectively (P<0.01 and P<0.05). Inhibitive effect of dexamethasone was stronger than that of p38MAPK inhibitor., Conclusions: The co-stimulation of poly(I:C) and LPS can induce chemokine expression of airway epithelial cells. Poly(I:C) enhances the IL-8 expression induced by single LPS challenge, which suggests that viral infection could enhance the inflammation resulted from bacterial colonization in airway. Glucocorticoid has the greater effect on the inhibition of chemotactic factors production than p38MAPK inhibitor. These two drugs have a potential therapeutic effect on AECOPD caused by viral infection.

Objective: To develop a nanobiosensor for rapid colorimetric detecting Mercury (II) Ions (Hg(2+)) in water by mercury-specific oligonucleotides (MSOs) probe and gold nanoparticles., Methods: The nanobiosensor was assembled by adsorbing the optimized MSOs on the surface of gold nanoparticles. A direct colorimetric probe of Hg(2+) which relied on the T-T mismatches in DNA duplexes was used to selectively and strongly capture Hg(2+). Hg(2+) induces the aggregation of gold nanoparticles with appropriate amount of salts, resulting the color change (red to blue)., Results: The diameter and concentration of the gold nanoparticle preparation were 15 nm and 2.97 nmol/L, respectively. Truncated MSOs (9 bp) showed the similar Hg(2+)-binding activity. The optimum concentration of the NaNO3 solution was 0.5 mol/L. The nanobiosensor could detect Hg(2+)in a range of 10 ∼ 1000 µmol/L within few minutes and the specificity was 100%., Conclusion: A new nanobiosensor is developed successfully for rapid colorimetric detecting Hg(2+) in water, avoiding either MSOs labeling or gold nanoparticles modification. This technique is simple, convenient and rapid detecting method with high sensitivity and specificity.

Objective: To verify the feasibility and safety of new vascular interventional robot system used in vascular interventional procedures., Methods: Vascular interventional robot type-2 (VIR-2) included master-slave parts of body propulsion system, image navigation systems and force feedback system, the catheter movement could achieve under automatic control and navigation, force feedback was integrated real-time, followed by in vitro pre-test in vascular model and cerebral angiography in dog. Surgeon controlled vascular interventional robot remotely, the catheter was inserted into the intended target, the catheter positioning error and the operation time would be evaluated., Results: In vitro pre-test and animal experiment went well; the catheter can enter any branch of vascular. Catheter positioning error was less than 1 mm. The angiography operation in animal was carried out smoothly without complication; the success rate of the operation was 100% and the entire experiment took 26 and 30 minutes, efficiency was slightly improved compared with the VIR-1, and the time what staff exposed to the DSA machine was 0 minute. The resistance of force sensor can be displayed to the operator to provide a security guarantee for the operation. No surgical complications., Conclusions: VIR-2 is safe and feasible, and can achieve the catheter remote operation and angiography; the master-slave system meets the characteristics of traditional procedure. The three-dimensional image can guide the operation more smoothly; force feedback device provides remote real-time haptic information to provide security for the operation.

Objective: To evaluate the impact of resveratrol on coronary collateral circulation in pigs suffered from experimental acute coronary occlusion., Methods: Eighteen healthy pigs were randomly divided into 3 groups: resveratrol group, nitroglycerin group and control group. Animal model of acute coronary occlusion was established through PTCA method, and the blood flow spectrum in the left circumflex artery (LCX) was detected using intracoronary Doppler ultrasound., Results: The average peak velocity (APV) in infarction correlation artery (IRA) was significantly decreased immediately after coronary occlusion [(0.85 ± 0.25) cm/s vs. (24.83 ± 3.43) cm/s, P < 0.05]. The APV remained unchanged during 0, 30 and 60 minutes after the occlusion. Reversed or bidirectional blood flow was observed and the APV increased significantly [(9.22 ± 0.80) cm/s vs. (0.84 ± 0.21) cm/s, (8.93 ± 1.28) cm/s vs. (0.86 ± 0.26) cm/s respectively, P < 0.05] after the coronary injection of resveratrol (2 mg) or nitroglycerin (0.3 mg). There was no significant difference in peak APV between the resveratrol and nitroglycerin groups. The duration of increased APV was significantly longer in resveratrol group than that in nitroglycerin group [(58.83 ± 6.15) min vs. (21.80 ± 5.79) min, P < 0.05]., Conclusions: The collateral circulation after acute coronary occlusion was obviously insufficient in pigs. Resveratrol could significantly improve the blood flow in coronary collateral circulation after acute occlusion in this model.

Objective: To study whether N, N'-di-(m-methylphenyi)-3,6-dimethyl-1,4-dihydro-1,2,4,5-tetrazine-1,4-dicarboamide (ZGDHu-1) inhibits proliferation and induces apoptosis in human lung carcinoma cell line EBC-1 cells and its molecular mechanism., Methods: Different concentrations of ZGDHu-1 and different times of culture were used to treat EBC-1 cells in vitro. The inhibition of proliferation was measured by BrdU-ELISA. Cell apoptosis was detected by Annexin V/PI staining and cellular DNA fragmentation ELISA. Phosphorylated p38MAPK and STAT3 were examined by flow cytometry. The protein expressions of bcl-2, bax, p53, Fas, and caspase-3 were detected by Western blot analysis., Results: ZGDHu-1 inhibited EBC-1 cell proliferation within a certain range of treating times and does, with a 24 h IC(50) of (295 ± 25) ng/ml, 48 h of (112 ± 8) ng/ml and 72 h of (23 ± 2) ng/ml. The EBC-1 cell apoptosis was confirmed by Annexin V/PI labeling and cellular DNA fragmentation ELISA in a dose-related manner. When EBC-1 cells were treated with 50, 200, and 500 ng/ml ZGDHu-1 for 48 h, the expression rates of phosphor-p38MAPK protein were 67.4%, 88.2%, 91.1%, respectively, and that of the control was 10.6%. That of STAT3 protein were 56.5%, 43.6% and 34.6%, respectively, and that of the control was 89.1%. The expression of bax, p53 and Fas protein was significantly increased, that of bcl-2 was not changed, and that of caspase-3 was significantly decreased by the ZGDHu-1 treatment., Conclusion: ZGDHu-1 can inhibit proliferation and induce apoptosis in EBC-1 cells. The mitochondrial pathway mediated by Fas may be one of its mechanisms. The apoptosis of EBC-1 cells may associate with up-regulation of phosphor-p38MAPK and down-regulation of phosphor-STAT3 in the cells.

Nano-powders Y2O3 with various particle sizes and different doping concentrations of Ln (Ln = Tb, Tm, Eu) were prepared by using a combustion technique. The bulky powders doped with concentrations corresponding to nano-powders were obtained by annealing the nano-powders at high temperature. The emission spectra, XRD spectra and TEM were used in the present study. The concentration quenching of luminescent centers and energy transfer between luminescent centers in Y2O3 : Ln nanocrystal powders were investigated. It was found that the behaviors of luminescence concentration quenching for 5D4 --> 7F5 : Tb3+ and 5D0 --> 7F2 : Eu3+ in nano-powders are similar to that in bulky powders. On the contrary, the quenching concentrations for 5D3 --> 7F5 : Tb3+ and 1D2 --> 3H4 : Tm3+ are distinctly higher than that in bulk powders. This owes to the size confinement effect: the interface of nanocrystal particles can stop a portion of the energy transfer, which happens in the bulk ones, between luminescent centers. The size confinement effect can bring different influences to the different types of energy transfer. For instance, it will restrain the energy transfer (governed by electric dipole-dipole interaction) between the ions in long distances, and will hardly affect the energy transfer (governed by exchange interaction) between the ions locating at near intervals.

Objective: To construct a replication-incompetent recombinant adenovirus mediating short hairpin RNA (shRNA)-induced tissue factor gene silencing in the islet., Methods: Four pairs of complementary oligonucleotides were designed and synthesized to create double-stranded oligonucleotides (ds oligo). The ds oligos were cloned into Pentr/U6 vector to construct the shuttle plasmid pENTR/U6-shRNA, which was transduced into human islets via liposome after sequence verification. The plasmid with the best silencing effect was identified by real-time RT-PCR, followed by homologous recombination with the adenovirus backbone plasmid. The functional clone was transfected into 293A cells to amplify the adenovirus, whose silencing effect against TF expression was tested using real-time RT-PCR and Western blotting., Results: The pENTR/U6-shRNA shuttle plasmid was constructed and verified by sequencing. The recombinant adenovirus-mediated shRNA against TF was constructed, and real-time RT-PCR and Western blotting demonstrated that the strongest silencing effect of the adenovirus against TF occurred on the 4th day following islet transfection., Conclusion: Replication-incompetent recombinant adenovirus-mediated shRNA against TF has been successfully constructed, which has good silencing effect against TF expression in human islet in vitro.

Objective: To observe the effects of Ginkgo biloba extract (GBE) on N-methyl-D-aspartate (NMDA) excitotoxicity and focal cerebral ischemia, and further explore the neuroprotective mechanisms of GBE., Methods: Neonatal SD rat hippocampus was taken out to make into cell suspension. immunohistochemistry with neuron nucleoprotein monoclonal antibody (NeuN) was used to calculate the percentage of NeuN positive cells. Twelve days after incubation the suspension of neurons were randomly divided into 4 groups: normal control group (exposed to normal saline for 15 min and then to DMEM without NMDA and glycine for 24 h), NMDA group (exposed to culture fluid with NMDA of the terminal concentration of 100 micromol/L and glycine of the terminal concentration of 10 micromol/L for 15 min and then to DMEM without NMDA and glycine for 24 h), MK-801 group (exposed to MK-801, an NMDAR antagonist, for 2 min, to culture fluid with NMDA for 15 min, and then to DMEM without NMDA and glycine for 24 h), and GBE pretreatment group (exposed to GBE of the terminal concentration of 150 microg/ml for 3 d, culture fluid with NMDS for 15 min, and then to DMEM without NMDA and glycine foe 24 h). Trypan blue staining was used to calculate the survival rate of the neurons. The lactic dehydrogenase (LDH) level in the supernatant of cultured cell suspension was detected. Whole-cell patch clamp recording was carried out to evaluate the modulatory effects of GBE on NMDA-activated currents in the rat hippocampal neurons. 108 SD rats were randomly divided into 5 groups: sham operation group (n = 12), standard middle cerebral artery occlusion (MCAO) group (n = 24, undergoing MCAO and then reperfusion), MK-801 acute administration group (n = 24, undergoing MCAO and immediate peritoneal administration of MK-801 1 mg/kg), GBE acute administration group (n = 24, undergoing peritoneal injection of GBE 100 mg/kg immediately after the MCAO), and GBE pretreatment group (n = 24, undergoing peritoneal administration of GBE every day for 7 days before the MCAO). The 4 groups were re-divided into 4 subgroups with 3 approximately 4 rats: 0.5 h ischemia, and 3 h, 1 d, and 7 d ischemia-reperfusion (IR) subgroups. The neurological symptoms were evaluated by Longa's scoring after the rats became conscious. The rats were killed at different time-points, their brains were taken out to undergo 2, 3, 5-triphenyl-tetrazolium chloride staining, the areas of cerebral infarction were calculated, and immunohistochemistry was used to evaluate the contents of NeuN and microtubule-associated protein (MAP-2)., Results: The cell viability of the GBE group was 85% +/- 5%, significantly higher than that of the NMDA group (39.8% +/- 2.1%, P < 0.01), and significantly lower than that of the MK-801 group (93.8% +/- 2.7%, P < 0.05). The LDH efflux of the GBE group was 87 U/L +/- 8 U/L, significantly lower than that of the NMDA group (138 U/L +/- 12 U/L, P < 0.01) and significantly higher than that of the MK-801 group (47 U/L +/- 7 U/L, P < 0.05). The inward current (I(NMDA)) of the NMDA group was significantly activated, The inhibitory rate of the NMDA-activated I(NMDA) of the GBE group was 40% +/- 17%, significantly lower than that of the MK-801 group (78% +/- 18%, P < 0.05); After washing out with standard extracellular solution, the I(NMDA) could recover to 91% +/- 8% in the GBE group, but not in the MK-801 group (P < 0.05), which indicated that GBE had lower affinity to NMDA receptor than MK-801. The Longa's scores of the 3 h and 24 h IR subgroups of the GBS pretreatment group were all significantly lower than those of the corresponding subgroups of the standard MCAO and GBE acute administration groups. The symptoms of the MK-801 were the most severe. Cerebral infarction began to appear in the 1-day subgroups. The cerebral infarction areas of the 1 d subgroups of the GBF pretreatment and MK-801 groups were 11.5% +/- 1.3% and 6.5% +/- 0.9% respectively, both significantly smaller than those of the MCAO and GBE acute administration groups (24.5% +/- % and 22.9% +/- 1.3% respectively, both P < 0.01), however, there was no significant difference in the cerebral infarction area between the GBE acute administration and MCAO group. It was true too for the cerebral infarction areas of the 7 d subgroups. Except in the control group, loss of NeuN positive neuron was seen in all groups, especially the MCAO and GBE acute administration groups. Except in the control group, the MAP-2 positive neurons were decreased in all groups, especially the MCAO and GBE acute administration groups, and 1 day and 7 days after the IR MAP-2 positive neurons were almost unseen in the MCAO and GBE acute administration groups, however, could be seen in small amounts in the GBE and MK-801 groups (all P < 0.01)., Conclusion: GBE pretreatment protects the neurons from excitotoxicity induced by over-activated NMDA receptor and focal cerebral ischemia, which can be explained by the mild blocking effect of GBE on NMDA receptor with low affinity, comparing with MK-801, and GBE is expected to interfere in excitotoxicity in clinic without neurotoxic behaviors.

In the present the authors are trying to work out how the quantum efficiency depends on the nanocrystalline size. Cubic nanocrystalline Y2O3 : Eu3+ samples were prepared by chemical self-combustion. The bulk Y2O3 : Eu3+ was obtained by annealing the nanocrystalline at 1 000 degrees C for 2 h. The emission spectra, XRD and fluorescence decay showed that the emission intensities are increased and fluorescence decay becomes slow with an increase in particle diameter of the samples. Two routes were used to estimate the quantum efficiency of the 5D0 level of Eu3+ at C2 site. The quantum efficiencies of 5D0 level of Eu3+ at C2 site in the samples depend on the nanocrystalline sizes. Finally, a detailed discussion about these two approaches for estimating the quantum efficiencies was made.

The ternary solid complexes RE(Et2dtc)3 (phen) (RE=La, Pr, Nd, Sm-Er) were synthesized with sodium diethyldithiocarbamate (NaEt2 dtc x 3H2O), 1,10-phenanthroline (o-phen x H2O) and hydrated lanthanide chlorides in absolute ethanol by improved reported method. IR results revealed that RE3+ coordinated with sulfur atoms of NaEt2 dtc and nitrogen atoms of o-phen. As for UV spectrum of the complexes, energy transfer between o-phen and RE3+ was the primary process, and the main absorption peaks showed a slight red shift compared to that of o-phen; FS spectrum, as a comparison, showed that the complexes Sm (Et2 dtc)3 (phen) and Eu(Et2dtc)3 (phen) have a higher efficiency of intermolecular energy transfer and a stronger fluorescence character.

Y(P, V)O4 :Eu3+ phosphors with good morphology for plasma display panels have been prepared via coprecipitation reaction. The phosphor was characterized by SEM and photoluminescence under UV (325 nm)and VUV (147 nm) excitation. The emission spectra depending on temperature under 325 nm excitation by laser indicated that there exist energy transfer between VO4(3-) group and Eu3+ ion. Under 147 nm excitation, the most intense emission peaks of commercial (Y,Gd)BO3 :Eu3+ phosphor range around 593 nm, and those of Y(P, V)O4 :Eu3+ phosphors prepared by coprecipitation reaction ranged around 619 nm. The red emission color purity of Y(P, V)O4 :Eu3+ phosphor is much better than that of (Y,Gd)BO3: Eu3+, and its relative emission intensity is almost close to that of the commercial phosphor.

Objective: To investigate modulation of gamma-aminobutyric acid (GABA) and its receptors on medial vestibular nucleus neurons in vivo., Methods: Twenty-six male Wistar rats were used. gamma-aminobutyric acid, bicuculline (BIC, gamma-aminobutyric acid A receptor antagonist) and 2-hydroxysaclofen (SAC, gamma-aminobutyric acid B receptor antagonist) were microiontophoresed on medial vestibular nucleus (MVN) neurons to determine the effects of gamma-aminobutyric acid and its antagonists on the neuronal firing rates of medial vestibular nucleus in rats in vivo., Results: Microiontophoretic application of y-aminobutyric acid at 10, 30, 50 nA electric current produced inhibitory responses on 42 MVN neurons, these responses were dose-dependent decreases, firing rates (x +/- s) of MVN neurons decreased form (14.8 +/- 5.6) times/s to (8.7 +/- 3.4) times/s, (4.1 +/- 1.6) times/s and (2.2 +/- 1.1) times/s respectively; microiontophoretic application of bicuculline in 37 MVN neurons, 86.5% (32/37) neurons produced excitatory responses, 13.5% (5/37) neurons didn't response, firing rates of MVN neurons increased form (15.3 +/- 6.3) times/s to (16.8 +/- 7.1) times/s, (25.9 +/- 10.1) times/s and (32.7 +/- 11.3) times/s respectively at 10, 30, 50 nA electric current, which were dose-dependent increases, and the inhibitory responses of gamma-aminobutyric acid on MVN neurons were blocked by bicuculline completely; however, microiontophoretic application of 2-hydroxysaclofen didn't produced responses as bicuculline did., Conclusions: Modulation of gamma-aminobutyric acid on medial vestibular nucleus neurons was mediated by y-aminobutyric acid A receptor in vivo.

Objective: To investigate the effects of teriparatide (hPTH1-34, PTH) and alendronate (Alen) on bone turnover rate and bone mineral density (BMD) of ovariectomized (OVX) osteoporotic rats., Methods: 70 female 6-month-old Wistar rats were randomly divided into 7 groups: (1) baseline group: killed immediately as baseline controls; (2) sham operation group: injected subcutaneously with normal saline (NS) as normal controls; (3) OVXb group: underwent ovarietomy (OVX) and killed 6 weeks after OVX as pre-therapeutic controls; (4) OVXe group: injected with NS subcutaneously and then sacrificed 14 weeks after OVX as controls by the end of treatment; (5) PTH group: PTH 40 microg.kg(-1).d(-1) was administered; (6) Alen group: Alen 100 microg.kg(-1).d(-1) was administered; (7) A + P group: PTH 40 microg.kg(-1).d(-1) and Alen 100microg.kg(-1).d(-1) were administered. In groups 4 approximately 7, different medicines were injected subcutaneously QD 5 times per week from the 6th week to the 14th week after OVX and then the rats were killed and their right femurs, lumbar vertebrae, and samples of blood and urine were collected. Absorptometry was used to measure the BMD of the right femur and lumbar vertebrae. The serum calcium, phosphate, creatinine, alanine transaminase, and alkaline phosphatase (ALP) activity were measured by automatic biochemical analysis. The bone resorption marker urine deoxypyridinoline/creatinine (UDpd/Cr) level was measured by enzyme-linked immuosorbent assay., Results: Six weeks after OVX the ALP and UDpd/Cr levels in the OVXb group were 101 U/L +/- 59 U/L and (118 +/- 32) x 10(-6) respectively, both significantly higher than those of the baseline group (58 U/L +/- 10 U/L and (48 +/- 34) x 10(-6) respectively, both P < 0.01) and the BMD results of the OVXb group were all significantly lower than those in the baseline group (all P < 0.01), which indicated that an OVX osteoporotic rat model was established successfully. The ALP and UDpd/Cr levels of the Alen group were 61 U/L +/- 28 U/L and (17 +/- 39) x 10(-6), significantly lower than those of the PTH group 120 U/L +/- 36 U/L and (111 +/- 26) x 10(-6) respectively, both P < 0.01) and the UDpd/Cr levels of the A + P group were between those of the Alen group and those of the PTH group. The BMD levels of the femur and lumbar vertebrae of the PTH, Alen, and A + P groups were all significantly higher than those of the control groups (all P < 0.01), and were similar to or higher than those of the sham operation group without significant differences between the PTH and Alen groups. The BMD level of the lumber vertebrae of the A + P group were significantly higher than those in the PTH group (all P < 0.05), and the femoral BMD results of the A + P group were significantly higher than those in the PTH and Alen groups (all P < 0.01)., Conclusion: PTH and Alen are all effective on osteoporosis. In particular, the combination of PTH and Alen is more effective on increasing the BMD level.

Objective: To study the emotional and depressive differences between severe acute respiratory syndrome (SARS) patients whose occupations were doctor/nurse and others., Methods: During the three months when SARS was explosive in 2003, 524 questionnaires were collected from Xuanwu Hospital, You'an Hospital, Xiaotangshan Hospital, Renmin Hospital and Ditan Hospital in Beijing. There were 109 questionnaires finished by patients as doctors/nurses themselves. For a background matching, 109 questionnaires were also finished by the others., Results: From 218 questionnaires, we found that the score on emotional condition (46.6204 +/- 8.4408 vs. 41.6789 +/- 8.612 95, P < 0.001) of SARS patients whose jobs were doctor/nurse was higher than the other groups on while the score of SARS patients whose jobs were doctor/nurse was lower than the other groups (37.7615 +/- 9.026 61 vs. 41.2844 +/- 9.655 25, P = 0.006) regarding depressive condition. The scores of emotional and depressive condition were all correlated with the factor as "I can not master my future"., Conclusion: Doctors/nurses having SARS had less emotional and depressive conditions than the others, which might due to the difference in medical knowledge, working condition and the route of infection, suggesting that psychological intervention in the post-SARS period called for attention.