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In order to improve the safety of outdoor natural gas stations and detect the natural gas leakage in the process area of the stations in time, a laser gas leakage monitoring system was designed according to the principle of absorbing the methane spectrum with laser, and a leakage monitoring method with high reliability and real-time that is applicable to the gas stations of West-East Pipeline was explored. Based on the long-term tracking of field application effect, the feasibility of application and popularization of the system was studied by comparison and observation. The results show that the laser gas leakage monitoring system can detect the gas leakage at natural gas stations more accurately from the levels of principle and application, and solve the problem of micro-leakage which cannot be automatically detected by the original technology, which reduces the potential safety risks of the natural gas stations and further lays a theoretical foundation for large-scale application in gas pipeline network in the future.

In order to reduce the frequency of false shutoff of the block valve in a long-distance gas pipeline and improve the reliability of the leakage detection system in a valve chamber, the leakage simulation model of a long-distance gas pipeline was established with SPS simulation software by referring to the theory of gas fluid mechanics based on the analysis on causes of a large number of false shutoff events occurred in valve chambers. With this simulation model, the influence rules of the conditions including the leakage location and operating pressure of a pipeline on the process of pressure drop during the leakage of a long-distance gas pipeline was studied, and on that basis, the process data of the possible maximum pressure drop during the leakage of a pipeline was calculated. Then, a judgment algorithm for false shutoff of block valves in a natural gas pipeline was designed, and a control procedure was developed for shutoff of block valves in a leaked pipeline. The simulation data and experimental results show that with the method, the false shutoff signal and the real leakage signal can be distinguished according to the characteristics of pressure change, and the rate of false shutoff of the system could be reduced.

Objective: To explore role of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome in idiopathic membranous nephropathy (IMN) and its possible mechanism of activation. Methods: A total of 135 patients with no adrenal corticosteroid and immunosuppressive therapy who were diagnosed with IMN by renal biopsy were collected, and 10 patients with renal tuberculosis and renal tumors who underwent nephrectomy were selected as control group. Immunohistochemical was used to detect NLRP3, tumor necrosis factor receptor-related factor 6 (TRAF6), Caspase-1, NF-κB p65, MAPK signaling pathway-related proteins, including phosphorylated ERK1/2 (p-ERK1/2), phosphorylated p38 (p-p38), phosphorylated JNK (p-JNK) expressions. Blood and 24-hour urine of IMN patients were collected, and 24-hour urine protein quantification, serum creatinine, creatinine clearance rate, blood urea nitrogen and other general clinical data were were analyzed, correlation between urine protein and NLRP3, Caspase-1, IL-1β, TNF- α, NLRP3 and TRAF6 were analyzed, respectively. Results: Compared with control group, 24-hour urine protein and serum creatinine of IMN patients were significantly increased (both P<0.05), and protein expressions of NLRP3 and Caspase-1 in kidney tissues of IMN patients were significantly increased (both P<0.05), among which renal tissue of stage II IMN patients had the highest protein expressions of NLRP3 and Caspase-1, IL-1β and TNF- α expressions were enhanced (both P<0.05), and IL-1β and TNF-α protein expressions in renal tissue of stage II IMN patients were the strongest, protein expressions of NF-κB p65, p-ERK1/2, p-p38 and p-JNK were significantly increased (all P<0.05) . 24-hour urinary protein of IMN patients was positively correlated with expression of NLRP3 protein in kidney tissues (r=0.689, P<0.01), positively correlated with Caspase-1 protein (r=0.614, P<0.000 1), positively correlated with IL-1β (r=0.708, P<0.000 1), positively correlated with TNF-α (r=0.594, P<0.01) . Conclusion: TRAF6 induces ERK1/2, p38 and JNK signaling pathways to stimulate activation of NLRP3 inflammasome through activation of NF-κB, which promotes occurrence of IMN and production of large amounts of urine protein. [ABSTRACT FROM AUTHOR]

A droop-free distributed energy storage control strategy based on the diffusion algorithm is proposed to address the inability of droop control to simultaneously achieve bus voltage stability and accurate power distribution among energy storage systems when the line impedance is mismatched and bus voltage is inconsistent. First, the diffusion algorithm is applied to the distributed estimation of direct current (DC) microgrid to obtain the global average, and the difference between the voltage rating and the average voltage is used as a compensation term to restore the bus voltage deviation. Then, in order to achieve the accurate distribution of power between energy storage systems with different rated capacities and different states of charge (SOC), a standard power of energy storage is designed and the difference between the standard power and the average standard power is used as a compensation term for the equilibrium of SOC between energy storage systems. Finally, a model based on RT-LAB is built to verify the effectiveness of the designed control strategy in four different operating modes. The experimental results show that the proposed control strategy can achieve the bus voltage recovery and the accurate distribution of energy storage power in the isolated DC microgrid.

In response to the defects of the traditional centralized economic dispatching strategy which needs to obtain global information and cannot adapt to the flexible topology of the system, and considering the coexistence of energy in the form of electricity and heat, a completely distributed cogeneration economic dispatching strategy based on the consistency algorithm is proposed. The incremental cost of electricity price and heat price of each unit in the cogeneration system is taken as the consistent variable to conduct the iterative calculation until the incremental cost converges to achieve the economic optimum of the system. In addition, the case of individual unit transmitting to neighboring units with deviating incremental cost values in order to enhance their own interests is also analyzed, and an incremental cost compensation term is designed to eliminate the impact of this selfish behavior. The simulation results indicate that the proposed strategy is effective and viable in the solution of the cogeneration economic dispatching problems.

Aimed at the impact of extreme weather on the stable operation of microgrid, an optimal configuration strategy of microgrid based on fuzzy scene clustering is proposed. Using historical weather data, a fuzzy scene clustering method is used to deal with the problem of new energy output fluctuations caused by random weather on the source side, and a robust optimization model is established on the load side to deal with load fluctuations within a certain range. Using scenes of 8 760 hours in a year, typical scenes and extreme scenes are obtained by distinguishing the unique membership characteristics of fuzzy scene clusters. Considering the impact of extreme scenarios on the optimal configuration of the microgrid, a two-stage robust model with the smallest comprehensive cost is established, which is decomposed by the column and constraint method, and is finally solved iteratively by Cplex solver. The effectiveness and feasibility of the proposed optimal configuration strategy are verified by simulation analysis.

The surface relaxivity for tight cores is commonly determined by the methods of average pore radius (ARS) or surface-to-volume ratio (SVR). The ARS method is time-consuming, and permanent damage to core samples will occur due to the injection of mercury. In this study, a non-destructive method is proposed, instead of the ARS method, to calculate the surface relaxivity of tight core samples based on T2 cut-off value. Firstly, surface relaxivity is calculated using the new method (pseudo T2 cut-off, PTC). Secondly, the calculated surface relaxivity of ARS and SVR methods are compared. Thirdly, the T2 spectrum is converted into pore diameter distribution by choosing appropriate surface relaxivity. Finally, residual oil distribution can be obtained. The ultimate surface relaxivity values for tight sandstone core samples are 5.85, 2.98, 4.66, and 2.17 μm/s. Moreover, we obtained the pore diameter distribution in mesopores and macropores by jointly using these three methods. Residual oil is mainly distributed in micropores and mesopores. The new method proposed in this study is nondestructive and is helpful to quickly and efficiently determine the surface relaxivity of tight cores.

A novel method for synthesizing carfentanil is researched in this work. N-Boc-protected piperidinone was used as the starting material. The carfentanil was achieved via synthetic rout involving five steps: Bargellini reaction, N-acylation, methylation, deprotection and N-alkylation. The overall yield of target compound was 31. 6%. The structures of intermediates and final product were determined by infrared spectroscopy, nuclear magnetic resonance spectroscopy and mass spectrograph. [ABSTRACT FROM AUTHOR]

Fa Shishan, who was greatly influenced by the Tang Dynasty's poets Wang Wei and Meng Haoran, was an important poet in the reigns of Qianlong and Jiaqing. His elegant poetic style was shaped by the poetic environment in the prosperous Qianlong Reign and by his disposition to rise above worldly desires. In his endeavor to make delicate descriptions in the manner of Wang and Meng, Fa tended to follow Du Fu and Bai Juyi and the poetic style of the late Tang Dynasty. Therefore, filled with his personal experience, humane care, and lofty aesthetic taste, Fa's poems indicate that when following Wang and Meng in poetic creation, he did not confine himself to that single poetic style, showing a diversified creation under the influence of the Tang Dynasty poetry. It is in his diversification of style that his unique value as a key poet in the Qing Dynasty lies. [ABSTRACT FROM AUTHOR]

Background Promoting appropriate health technology to rural and urban communities is an important measure to improve the technical level and service capacity of primary care institutions. The First Affiliated Hospital of Xinjiang Medical University carried out the promotion of appropriate health technology in southern Xinjiang. Objective To evaluate the effect of appropriate technology promotion for stroke rehabilitation in southern Xinjiang, understand the needs of rehabilitation workers in southern Xinjiang for appropriate technology promotion for stroke rehabilitation and the goals they hope to achieve by participating in appropriate technology promotion for stroke rehabilitation projects, providing a basis for health administrative departments to implement appropriate rehabilitation technology promotion work. Methods The rehabilitation workers from the rehabilitation medicine departments of 8 people's hospitals, affiliated township health centers and communities health centers, federation of the disabled, civil affairs system and other rehabilitation institutions in 8 deep poverty-stricken counties which were considered as sample source sites by using a multi-stage sampling method in July 2018. The appropriate technology promotion for stroke rehabilitation was performed followed by a investigation by using self-designed questionnaire. The monthly outpatient volume, hospitalization volume and treatment income of the rehabilitation medicine department of people's hospitals before (January 1, 2018 to June 30, 2018) and after participation (July 1, 2020 to December 31, 2020) in technology promotion for stroke rehabilitation projects were compared. Results The appropriate technology promotion for stroke rehabilitation in acute, subacute and convalescent stages, as well as community and family rehabilitation of stroke was performed from January 1, 2018 to June 30, 2018, involving motor function rehabilitation training, functional electrical stimulation, mandatory exercise therapy techniques, constraint induced movement therapy (CIMT) , mirror therapy, management and rehabilitation training of dysphagia, daily living activities training and rehabilitation care of stroke patient. A total of 384 valid questionnaires were collected. Among the 384 rehabilitation workers, 63.3% (243/384) identified the appropriate technology promotion within districts (counties) as very meaningful; 46.1% (177/384) thought the project was very applicable in their local area; 37.5% (144/384) believed that the technology for stroke rehabilitation can be carried out in their medical institutions with a slight improvement of the relevant conditions; 46.9% (180/384) believed that the difficulty level of the appropriate technology promotion project was easy in terms of operation skills; after the training, 42.2% (162/384) claimed to be knowledgeable about the technology and need to learn and receive further training. The monthly outpatient volume and monthly treatment income of the rehabilitation medicine department of people's hospitals after participating in stroke rehabilitation technology promotion projects increased significantly compared with before participation (P

In order to investigate the effects of electric pulses on cancer cells, we carried out the experiments with exposing HepG2 and L02 to electric pulses (1 kV/cm, l00 micros, 1 Hz) for different lengths of time (8 s, 15 s, 30 s, 60 s). Annexin V-FITC Kit and Flow cytometry were used to study the apoptosis of treated cells. The results showed that the electric pulses of 1 kV/cm, l00 micros, 1 Hz for 8 s could not induce tumor cells apoptosis. Apoptosis was observed when tumor cells were stimulated for 15 s and longer, and the apoptosis percentage increased with the increase of stimulation time. Furthermore, tumor cells were more sensitive than normal cells in response to electrical pulses. Rhodamine 123 and Laser Scanning Confocal Microscope (LSCM) were used to make a real-time study of mitochondrial transmembrane potential (Deltapsim) when the tumor cells were exposed to electric pulses for 60 s. No significant change of Deltapsim was observed within 30 s stimulation. After that, the Deltapsim increased sharply and declined later, suggesting that the mitochondrial pathway may be one of the apoptosis mechanism induced by electric pulses.

Based on multi-layer dielectric model of spherical biological cell, a simulating method of frequency characteristics of inner and outer membranes is presented in this paper. Frequency-domain analysis showed that inner and outer membranes subjected to pulsed electric field exhibit band-pass and low-pass filter characteristics, respectively. A calculating method of the transmembrane potential of inner and outer membranes induced by time-varying electric field was introduced, and the window effect between electric field and transmembrane potential was also analyzed. When the duration is reduced from microsecond to sub-microsecond, and to nanosecond, the target induced was from the outer membrane to inner membrane gradually. At the same time, the field intensity should be increased to induce corresponding bioelectric effects. Window effect provides theoretical guidance to choosing reasonable parameters for application of pulsatile electric field in tumor treatment.

In the light of optical theory, we advanc an ultra-wideband impulse radiating antenna (IRA) which is composed of an ellipsoidal reflector and a cone radiator. The high-intensity ultra-short electric pulses radiated by IRA can be transferred into the deep target in tissue non-invasively and be focused effectively. With the focused picosecond electric pulses, the organelles (mitochondria) transmembrane potential shall change to collapse under which the tumor cells will be targetly induced to apoptosis, so the method of non-invasive treatment of tumors would be achieved. Based on the time-domain electromagnetic field theory, the propagation characteristics of picosecond electric pulses were analyzed with and without the context of biological tissue, respectively. The results show that the impulse characteristics of input pulse were maintained and the picosecond electric pulses can keep high resolution in target areas. Meanwhile, because of the dispersive nature of medium, the pulse amplitude of the pulses will attenuate and the pulse width will be broadened.

In spite of receiving chemotherapy, the response of patients with cancer can be extremely variable. Chemosensitivity testing is being applied in institutes and some hospitals to improve the effects of chemotherapy. It would be useful for choosing the most effective drug and strategy for individual chemotherapy and to exclude the resistance of the tumor cells. In this way, the individualized chemotherapy can be established. Up to today, there are more than 10 approaches established for chemosensitivity testing assays, such as single cell culture assay (including MTT, MTS, ATP), nude mouse model sensitivity examination, collagen gel droplet embedded culture drug sensitivity test and histoculture drug response assay etc. This paper reviews some current methods, and their possibility for directing clinical chemotherapy.

Objective: To test the effect of recombinant human tumor necrosis factor-alpha (rhTNF-alpha) labeled with 131I on tumor growth in the nude mice bearing human hepatoma., Methods: The biological activity of 131I-rhTNF-alpha was tested through in vitro combination of the radioactive drug and SMMC-7721 cells. The BALB/c-nu/ nu mice model bearing human hepatoma were established by injecting single cell suspension of SMMC-7721 cells. When the tumor was 1 cm in diameter, the therapeutic experiment was carried out. Twenty-four nude mice bearing human hepatoma were divided into six groups according the area of tumor, weight and sex of the nude mice. After i. v administration of 131I-rhTNF-alpha, the body biodistribution of 131I-rhTNF-alpha was assessed during a short-term (30 min, 1 h, 6 h) and a long-term (12 h, 24 h, 48 h) period. The biological activity and tumor accumulation of 131I-rhTNF-alpha were investigated. In the end of the experiment, histopathologic examinations of tumor samples were undertaken., Results: The combination of 131I-rhTNF-alpha with the human hepatoma SMMC-7721 cells existed dose dependence and saturability. The 131I-rhTNF-alpha had satisfactory immunoreactivity. The 131I-rhTNF-alpha accumulated in tumor tissues well and kept stable for several days. The tumor tissues accumulated the highest radioactivity at 6 h, and still maintained 67.5% of that radioactivity at 48 h. The 131I-rhTNF-alpha administrated either intravenously or intratumorally could inhibit tumor growth. The 131I-rhTNF-alpha had similar radioactivity as the positive control (P>0.05), but greater radioactivity than the control groups including 131I, rhTNF-alpha and the negative groups (P<0.05)., Conclusion: The radioactive compound of 131I-rhTNF-alpha can inhibit and kill tumor cells, which demonstrates its potential for treating hepatocarcinoma.

The aim of our study was to determine the effects of energy controllable steep pulse (ECSP) on the cytoskeleton of human ovarian cancer cells SKOV3. SKOV3 cells were divided into five groups under ECSP treatment with different parameters (frequency, pulse duration, peak value of voltage). The positive control group included SKOV3 cells treated with volchicine; the negative control group included SKOV3 cells subjected to sham-lightning stroke. Rhodamine-phalloidine was used to label microfilament directly. After using immunofluorescence to label microbules, we observed them by means of Confocal Laser Scanning Microscope. Making specimen and using electronmicroscope, we observed the ultramicrostructure of cystoskeleton. The results showed that ECSP-treated-SKOV3 cells lost their normal cystoskeleton network structure. There were obvious microfilament disaggregation, diffused skeleton protein, and disappearance of cystoskeleton network structure. Also noticeable were microbule disaggregation, reduction of pseudopod, obvious microfilament disaggregation, permutation disorder and structure disappearance. Moreover, this effect bears a direct relation with dosage.

This experiment was designed to study the apoptosis and related mechanism of adherent liver tumor cells (SMMC-7721) and adherent normal liver cells (HL-7702) when they were exposed to the steep pulse generated by the steep pulse apparatus for tumor treatment. The results showed that the steep pulse of 200 V could induce tumor cells apoptosis. The tumor cells presented with their apoptosis when they were exposed to the steep pulse from 200 V to 250 V. Laser scanning confocal microscopy was used to make a real time study of calcium burst when the adherent tumor cells were exposed to the steep pulse. The results showed:On the condition of no extracellular Ca2+, the concentration of Ca2+ in tumor cells exposed to the steep pulse of 150 V did not change; the concentration of Ca2+ in tumor cells exposed to the steep pulse of 200 V decreased; the concentration of Ca2+ in tumor cells exposed to the steep pulse of 250 V decreased more evidently. On the condition of existing extracellular Ca2+, the concentration of Ca2+ in tumor cells exposed to the steep pulse of 150 V did not change; the concentration of Ca2+ in tumor cells exposed to the steep pulse of 200 V decreased little; the concentration of Ca2+ in tumor cells exposed to the steep pulse of 250 V reduced little, too. Maybe the change of calcium burst in the tumor cells is the mechanism of apoptosis when cells are exposed to the steep pulse.

As a micro-wound and target-aimed technology without special limitation, Electric Pulses have been widely researched in tumor treatment and the effects have been demonstrated by a series of experiments, yet the mechanism has not been explained clearly. In this experiment, energy controllable steep pulse (ECSP) was used to treat nude mice bearing human ovarian tumor, and the result was compared with that of the control group. The expression of an important coagulant factor-tissue factor (TF) was analyzed, as TF was also a tumor indicator of invasion and metastasis, the result may indicate the relationship among ECSP, thrombosis and tumor invasion. In this study, to shed light on the mechanism of tumor treatment in electrical fields, nude mice bearing ovarian tumors were randomly divided into the treated group and the untreated group. We treated the former group and took out the tumor instantly. The thrombosis and necrosis of ovarian tumor were observed under microscope. The expression of TF was analyzed by SP immunohistochemistry and RT-PCR. Lower level of TF expression was noticed in the tumor tissue treated by ECSP, and more apparent thrombosis was also seen in this group. The results make it clear that ECSP can accelerate thrombosis and consume coagulant factors such as TF, and that low expression of TF in tumor tissue can cut out the signal paths of tumor invasion. So it is suggested that ECSP may restrain tumor invasion and metastasis by modulating thrombosis.

This experimental study was designed to investigate the effects and the expressions of microvessel density (MVD), vascular endothelial growth factor (VEGF) on the transplanted tumor in the rat model with Walker-256 after energy controllable steep pulse(ECSP). The experiment revealed that the steep pulse electrical field has better effect on tumor, compared with the control. The positive cell staining intensity of VEGF in the control group was significantly higher than that in ECSP group (P < 0.05). The number of MVD in the tumor tissues of ECSP group was significantly lower than that of tumor control group (P < 0.05). These results showed that ECSP could inhibit the growth and angiogenesis of tumor and its pathway is to down-regulate the expression of VEGF possibly.

This study sought to evaluate the effect of steep pulsed electric fields (SPEFs) on the immune response of Wistar mice inoculated with Walker256 sarcoma. Thirty mice were randomly divided into three groups: control group (group A, inoculated with Walker256 sarcoma, not treated), treatment group (group B, inoculated with Walker256 sarcoma, treated by SPEFs), and normal control group (group C, inoculated with normal saline, not treated). Tumor size was measured before and every 3 days after treatment by vernier caliper. MTT methods were used to assess the lymphocytes proliferation and the natural killer (NK) cells activity. TNF-a activity was measured by ELISA. Statistical analysis was performed utilizing the SPSS10.0 software package. The experiment results revealed that tumor growth was significantly inhibited in group B as compared with group A (P < 0.01), and that lymphocytes proliferation, NK cells activity and TNF-a activity in group B were not significantly different from those in group C (P = 0.953, P = 0.130, P = 0.080, respectively) but markedly higher than those in group A (P < 0.05). The results also showed that SPEFs could not only kill tumor cells but also induce antitumor immune response and improve the immune function of the host efficiently.

This study was conducted to observe the lethal effects of steep pulsed electric field(SPEF) on the cancerous squamous cells in BALB/c mice. Female mice were inoculated with the solution of cervical cancer cells line. The tumor-bearing mice of the experiment group were exposed to SPEF. Then, the histomorphological changes were examined and compared between experiment group and control group. The histological and antitumor assay showed that SPEF could selectively injure tumor cells and inhibit cell proliferation. After treatment, pyknosis, karyoclasis and karyolysis of cancer cells were observed under light and electron mircroscope. More serious changes appeared some days later. These results indicate that SPEF have lethal effects on cervical cancer. It may prolong the survival period of tumor-bearing mice.

To assess study the cytocidal and inhibitory effects of steep pulsed electric fields (SPEFs) on ovarian cancer cell line SKOV3, the cancer cell suspension was treated by SPEFs with different parameters (frequency, pulse duration, peak value of voltage). Viability rate and growth curves of two test groups (high dosage and low dosage of SPEFs) and one control group were also measured. The DNA contents and cell cycle were analyzed by flow cytometry (FCM). Different dosing levels of SPEFs exerted obviously different effects on cancer cell viability. With the enhancement of each pulse parameter, the viability rate was promoted and the inhibitory effect on the proliferation of treated cells was more evident. The cells exposed to SPEFs grew slower than the control. The ratio of S+G2/M phase cells was decreased, which restrained the DNA synthesis and division, but the ratio of G0/G1 phase cells was increased in the treated groups. It was also indicated that the SPEFs blocked the cell transition from G0/G1 phase to S+G2/M phase. There was a significant difference in cell cycle between treated group and control group (P<0.01). Lethal effects of SPEFs were represented by inhibiting the cancer cell proliferation at the cell level and by influencing the cell cycle at the DNA level.

To investigate the lethal effect of steep pulsed electric fields (SPEFs) on cancer cells and the life-prolonging effect of SPEFs on the survival of tumour-bearing mice, this study was carried out with the use of SPEFs to treat 40 BALB/C mice inoculated by cervical cancer. The lethal effect on cancer cells and the life-prolonging effect on tumour-bearing mice were examined and compared between the experiment group and control group. The survival periods of the experiment group and control group were 52.05 days and 33.03 days, respectively. There was a significant difference in survival curve between the two groups. The results confirmed the inhibitiory effect and lethal effect of SPEFs on cancer cells. SPEFs can prolong the survival period of tumour-bearing mice.

In these years, the electrical technology is widely applied in the study of biomedical engineering. Using electroporation therapy (EPT) to treat tumor is associated with biomedical engineering, electrical new technology, computer technology and microelectronic technology, which is a new marginal subject. Many experts have studied the mechanism and clinical treatment of the cell membrane electroporation phenomenon under electrical fields. These researches have shown that the membrane electroporation can stimulate the transport and intake of various drugs, which improves the tumoricidal effect of these drugs. The researchers have also been exploring the phenomenon that irreversible electrical breakdown (IREB) of cell membrane under high electrical fields and steep pulses leads to the death of tumor.