This paper describes a technology of dynamic display moving image by computer monitor,which is initially used in the design of tool detection system. The paper presents the hardware and software principie and edge det...This paper describes a technology of dynamic display moving image by computer monitor,which is initially used in the design of tool detection system. The paper presents the hardware and software principie and edge detection process. The way of marking edge point coordinates and stability of moving image also is analyzed. The method reforms the conventional design of the 2-D vision detection system. Moreover,it facilitates the design of the systematic mechanical construction,is convenient to compile instrument systemsoftware,and realizes to detect and track display image simultaneously. By the work,the tool detection system is improved to practical application.展开更多
Testing methods of instrumental system in the marine magnetic survey have been studied in this paper, and the feasibility of each method has been testified by the observed data. The conclusion shows that the method br...Testing methods of instrumental system in the marine magnetic survey have been studied in this paper, and the feasibility of each method has been testified by the observed data. The conclusion shows that the method brought out can effectively eliminate the systematic error caused by the instrumental system, and greatly improve the surveying precision and the reliability of the survey results.展开更多
In order to detect and process underground vibration signal, this paper presents a system with the combination of software and hardware. The hardware part consists of sensor, memory chips, USB, etc. , which is respons...In order to detect and process underground vibration signal, this paper presents a system with the combination of software and hardware. The hardware part consists of sensor, memory chips, USB, etc. , which is responsible for capturing original signals from sensors. The software part is a virtual oscilloscope based on LabWindows/CVI (C vitual instrument), which not only has the functions of traditional oscilloscope but also can analyze and process vibration signals in special ways. The experimental results show that the designed system is stable, reliable and easy to be operated, which can meet practical requirements.展开更多
Aim The several species of the genus Paris called "Chonglou" are famous traditional Chinese herbal medicines. We established the quantitative analysis method of the steroidal saponins in some species of the genus Pa...Aim The several species of the genus Paris called "Chonglou" are famous traditional Chinese herbal medicines. We established the quantitative analysis method of the steroidal saponins in some species of the genus Paris and discussed their relations. Methods We detected the contents of 11 steroidal saponins in Paris samples with a Kromasel C18 ( 150 mm× 4.6 mm ID, 5μm) column which was subjected to gradient elution with acetonitrile-water (30:70- 60:40, V/V) at a flow rate of 1 mL· min^-1 by HPLC-ELSD and established chemical cluster tree using SPSS 11 software. Results All the samples could be separated and calibration curves of 11 saponins were prepared. We successfully detected the contents of 11 steroidal saponins in 14 Paris spp. in 30 min. The recovery for the assay of saponins was between 95 % and 97 %. The RSD of precision of 11 saponins and stability of samples were below 3 %. Chemical phylogenetic tree based on saponin contents indicated that 17 samples of Paris spp. clustered separately. Conclusion The established method is accurate and convenient, and suitable for the quantitative analysis of these 11 steroidal saponins in Paris spp.. The chemical phylogenetic tree is in accordance with Takhtajian classical taxonomy.展开更多
A novel closed-loop control strategy of a silicon microgyroscope (SMG) is proposed. The SMG is sealed in metal can package in drive and sense modes and works under the air pressure of 10 Pa. Its quality factor reach...A novel closed-loop control strategy of a silicon microgyroscope (SMG) is proposed. The SMG is sealed in metal can package in drive and sense modes and works under the air pressure of 10 Pa. Its quality factor reaches greater than l0 000. Self-oscillating and closed-loop methods based on electrostatic force feedback are adopted in both measure and control circuits. Both single side driving and sensing methods are used to simplify the drive circuit. These dual channel decomposition and reconstruction closed loops are applied in sense modes. The testing results demonstrate that useful signals and guadrature signals do not interact with each other because of the decoupling of their phases. Under the condition of a scale factor of 9. 6 mV/((°) .s), in a full measurement range of±300 (°)/s, the zero bias stability reaches 28 (°)/h with a nonlinear coefficient of 400 × 10^-6 and a simulated bandwidth of more than 100 Hz. The overall performance is improved by two orders of magnitude in comparison to that at atmospheric pressure.展开更多
AIM:To investigate the inhibitory effect of acetylshikonin on human gastric carcinoma cell line SGC-7901 and its mechanism. METHODS:MTT assay was used to assess the inhibitory effect of acetylshikonin on proliferation...AIM:To investigate the inhibitory effect of acetylshikonin on human gastric carcinoma cell line SGC-7901 and its mechanism. METHODS:MTT assay was used to assess the inhibitory effect of acetylshikonin on proliferation of SGC-7901 cells.Apopt osis-inducing effect was determined by flow cytometry and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling with Hoechst staining.Expression of mRNA and protein in Bcl-2 and Bax was analyzed by reverse transcription-polymerase chain reaction and Western blot.Antitumor effect of acetylshikonin on a mouse SGC-7901 model was also determined. RESULTS:Forty-eight hours after treatment with acetylshikonin,MTT assay showed that acetylshikonin inhibited the proliferation of SGC-7901 cells in a dose-dependent manner.The half maximal inhibitory concentration of acetylshikonin to SGC-7901 cells was 0.428±0.07 mg/L.Cell shrinkage,nuclear pyknosis and chromatin condensation,which are the characteristics of cell apoptosis,were observed in treated SGC-7901 cells and the percentage of apoptosis increased in a dose-dependent manner.Acetylshikonin downregulated the expression of Bcl-2 and up-regulated the expression of Bax in the treated SGC-7901 cells compared with the controls.The experiment in vivo showed that 0.5,1,and 2 mg/kg of acetylshikonin significantly inhibited the growth of tumor in the mouse SGC-7901 model,with an inhibitory rate of 25.00%-55.76%. CONCLUSION:Acetylshikonin inhibits the growth of SGC-7901 cells in vitro and in vivo by inducing cell apoptosis.展开更多
Vehicle detectition in still images is a comparatively difficult task. This paper presents a method for this task by using boosted local pattern detector constructed from two local features including Haar-like and ori...Vehicle detectition in still images is a comparatively difficult task. This paper presents a method for this task by using boosted local pattern detector constructed from two local features including Haar-like and oriented gradient features. The whole process is composed of three stages. In the first stage, local appearance features of vehicles and non-vehicle objects are extracted. Haar-tike and oriented gradient features are extracted separately in this stage as local features. In the second stage, Adabeost algorithm is used to select the most discriminative features as weak detectors from the two local feature sets, and a strong local pattern detector is built by the weighted combination of these selected weak detectors. Finally, vehicle detection can be performed in still images by using the boosted strong local feature detector. Experiment results show that the local pattern detector constructed in this way combines the advantages of Haar-like and oriented gradient features, and can achieve better detection results than the detector by using single Haar-like features.展开更多
To relieve the increasing traffic load, many early built highways need to be widened or reconstructed. The rapid performance detection to existing subgrades is important to their reasonable evaluation and maximized ut...To relieve the increasing traffic load, many early built highways need to be widened or reconstructed. The rapid performance detection to existing subgrades is important to their reasonable evaluation and maximized utilization. Based on five kinds of soils taken from an existing highway in southern China, three commonly detecting methods were used to determine their moisture contents, compaction degrees and resilient moduli. The results showed that the measured moisture contents were greater than the design value, and the compaction degrees decreased sharply compared to the original ones. The moisture and heat exchange produced a decrease in the resilient modulus of plate loading test(PLT) from the standard 60 MPa down to 40 MPa. Afterwards, the portable falling weight deflectometer(PFWD) and dynamic cone penetrometer(DCP) were used to evaluate the subgrade performances. The measured PFWD moduli and the DCP penetration rates were correlated with the resilient moduli of PLT, deflections of the Beckman beam test, compaction degrees and moisture contents. The correlation analysis indicates that both of two methods are suitable in rapid detecting subgrade performances, but PFWD method is more recommended for it has higher accuracy and efficiency.展开更多
AIM: To investigate if high-definition (HD) colonoscope with i-Scan gave a higher detection rate of mucosal le- sions vs standard white-light instruments. METHODS: Data were collected from the computer- ized datab...AIM: To investigate if high-definition (HD) colonoscope with i-Scan gave a higher detection rate of mucosal le- sions vs standard white-light instruments. METHODS: Data were collected from the computer- ized database of the endoscopy unit of our tertiary referral center. We retrospectively analyzed 1101 con- secutive colonoscopies that were performed over 1 year with standard white-light (n = 849) or HD+ with i-Scan (n = 252) instruments by four endoscopists, in an outpatient setting. Colonoscopy records included patients' main details and family history for colorectal cancer, indication for colonoscopy (screening, diagnos- tic or surveillance), type of instrument used (standard white-light or HD+ plus i-Scan), name of endoscopist and bowel preparation. Records for each procedure included whether the cecum was reached or not and the reason for failure, complications during or imme- diately after the procedure, and number, size, location and characteristics of the lesions. Polyps or protruding lesions were defined as sessile or pedunculated, and nonprotruding lesions were defined according to Paris classification. For each lesion, histological diagnosis was recorded. RESULTS: Eight hundred and forty-nine colonosco- pies were carried with the standard white-light video colonoscope and 252 with the HD+ plus i-Scan video colonoscope, The four endoscopists did 264, 300, 276 and 261 procedures, respectively; 21.6%, 24.0%, 21.7% and 24.1% of them with the HD+ plus i-Scan technique. There were no significant differences be- tween the four endoscopists in either the number of procedures done or the proportions of each imaging technique used. Both techniques detected one or more mucosal lesions in 522/1101 procedures (47.4%). The overall number of lesions recognized was 1266; 645 in the right colon and 621 in the left. A significantly higher number of colonoscopies recognized lesions in the HD+ plus i-Scan mode (171/252 = 67.9%) than with the standard white-light technique (408/849 = 48.1%) (P 〈 0.0001). HD+ with i-Scan colonoscopies identified more lesions than standard white-light imag- ing (459/252 and 807/849, P 〈 0.0001), in the right or left colon (mean :1: SD, 1.62±1.36 vs 1.33±0.73, P 〈 0.003 and 1.55±0.98 vs 1.17±0.93, P = 0.033), more lesions 〈 10 mm (P 〈 0.0001) or nonprotruding (P 〈 0.022), and flat polyps (P = 0.04). The cumulative mean number of lesions per procedure detected by the four endoscopists was significantly higher with HD+ with i-Scan than with standard white-light imaging (1.82 ± 2.89 vs 0.95± 1.35, P 〈 0.0001). CONCLUSION: HD imaging with i-Scan during the withdrawal phase of colonoscopy significantly increased the detection of colonic mucosal lesions, particularly small and nonprotruding polyps.展开更多
Objective: To observe the expression of CD13/APN in peripheral blood lymphocytes and skin lesions of patients with advanced psoriasis vulgaris, and discuss its effect on the pathogenesis of psoriasis. Methods: CD 13...Objective: To observe the expression of CD13/APN in peripheral blood lymphocytes and skin lesions of patients with advanced psoriasis vulgaris, and discuss its effect on the pathogenesis of psoriasis. Methods: CD 13 expression in peripheral blood lymphocytes and skin lesions was detected by flow cytometry and imrnunohistochemical technique, respectively. Results were compared with those of healthy controls. Results: CD 13 expression was significantly higher in peripheral blood lymphocytes of patients with advanced psoriasis vulgaris than in that of healthy controls, and in skin lesions than in healthy skin tissues. The expression was mainly in the suprabasal layers of skin lesions, and positively correlated to PASI (R 0.78029). Conclusion: The significantly higher expression of CD13 in peripheral blood lymphocytes and skin lesions of the patients with advanced psoriasis vulgaris probably is related to immunological abnormality, blood vessel abnormality and proliferation of keratinocyte in the pathogenic course of psoriasis. It may be a novel and effective way to treat psoriasis with specific CD13 inhibitors.展开更多
Luster is one of the main factors in assessing fabric appearance. There are many different ways to definite and describe the luster, which result in disorder and discommodious in evaluation. Based on previous work, an...Luster is one of the main factors in assessing fabric appearance. There are many different ways to definite and describe the luster, which result in disorder and discommodious in evaluation. Based on previous work, an apparatus suited for the measure of lustre is developed. Which performed measure the reflection distribution of fabrics automatically. Then the objective judgment can be given by the geniophotometric curve. Finally taking several kind of specimens for example give the results to prove the effectiveness of the device.展开更多
A design for low power consumption inspection instrument, in which the ATMega32L is used as the control core, is presented. The reader with wireless identification based on RF technology is researched and the low-cost...A design for low power consumption inspection instrument, in which the ATMega32L is used as the control core, is presented. The reader with wireless identification based on RF technology is researched and the low-cost power is studied particularly. This instrument can be used in industry fields to measure temperature, humidity, gas concentration and other specifications, so it has wide applications and is worth to be extended.展开更多
Initially studied and developed by students in universities, the very small pico satellites (with a mass lower than 1 kg) are more and more considered for science applications. In particular, there are plans to use ...Initially studied and developed by students in universities, the very small pico satellites (with a mass lower than 1 kg) are more and more considered for science applications. In particular, there are plans to use them in constellations of small spacecraft for remote sensing of various regions of the magnetosphere. They require a payload with specific size, weight and power consumption. In order to respond to this demand, new instruments have to be developed. Those instruments should exhibit at least the same performances as those used in larger satellites while fulfilling the specific requirements imposed by the satellites size. For this reason, the authors currently develop a xylophone bar magnetometer (XBM) based on micro-electromechanical systems (MEMS) with integrated detector electronics. The principle of this magnetometer is based on a classical resonating xylophone bar. A sinnsoidal current oscillating at the fundamental bending resonant frequency of the bar is applied through the device, and when an external magnetic field is present, the resulting Lorentz force yields the bar to vibrate at its fundamental mode with a displacement directly proportional to the amplitude in one direction of the ambient magnetic field. When designing a MEMS XBM, the detection method is a crucial aspect. The measurement method largely influences the geometry of the magnetometer as well as the manufacturing technology. Due to the constraints in terms of size, weight and power consumption, the two most promising measurement methods are capacitive and piezoelectric ones. Several designs including these measurement techniques are presented and simulated under realistic conditions. First, designs including lateral electrodes for capacitive measurement are tackled based on Silicon-On-Insulator (SOI) process. For the piezoelectric detection, a new configuration based on Lead Zirconate Titanate (PZT)/Pt structure is introduced and leads to much better sensitivity than the traditional Pt/PZT/Pt sandwich structure. Finally, the principle of electronic circuits enabling high sensitivity and low power consumption are proposed.展开更多
Background:Stiffness is commonly assessed in relation to injury and athletic performance.The purpose of this research was to compare the validity and reliability of 3 in vivo methods of stiffness assessment using 1 c...Background:Stiffness is commonly assessed in relation to injury and athletic performance.The purpose of this research was to compare the validity and reliability of 3 in vivo methods of stiffness assessment using 1 cohort of participants.Methods:To determine inter-day reliability,15 female netballers were assessed for stiffness twice within 1 week using unilateral hopping(vertical stiffness),free oscillations of the calf,and myometry of various muscles of the triceps surae.To establish convergent construct validity,stiffness was compared to static and dynamic strength measurements.Results:Test–retest stiffness results revealed that vertical stiffness produced moderate to high reliability results and myometry presented moderate to very high reliability.In contrast,the free oscillation technique displayed low to moderate reliability.Vertical stiffness demonstrated a significa t correlation with rate of force development during a squat jump,whilst myometer stiffness measurements from 3 sites in the lower limb revealed significan correlations with isometric rate of force development.Further,significan negative correlations were evident between the eccentric utilisation ratio and various myometer stiffness results.No relationships were established between the free oscillation technique and any of the performance measurements.Conclusion:These results suggest that vertical stiffness and myometry are valid and reliable methods for assessing stiffness.展开更多
An ion mobility spectrometer equipped with a laser ionization source is used for the sensitive detection of benzene.Mobility spectra of the benzene are presented.We also discussed the mobility spectra at various conce...An ion mobility spectrometer equipped with a laser ionization source is used for the sensitive detection of benzene.Mobility spectra of the benzene are presented.We also discussed the mobility spectra at various concentrations and drift voltages.Detection limits are determined to be in the upper ppb_v range.In the end,the advantages and possibilities of this technique are briefly discussed.展开更多
In this article the problem of three-dimensional (3-D) reconstruction of scenes from terrestrial laser rangefinder data is processed, we present the simulations results of radiometric range function of the laser ran...In this article the problem of three-dimensional (3-D) reconstruction of scenes from terrestrial laser rangefinder data is processed, we present the simulations results of radiometric range function of the laser range finder imaging system for better optimization of maximum range detection with a given SNR (Signal-to-noise ratio). The study proposes a new reformulation of the radiometric Gaussian beam range equation on the basis of the photodetector active area. The adjustment of the optical and geometrical characteristics of the laser range finder so defined can be used to minimize the signal span to avoid the saturation of the detector cell and improve the ranging measurements (accuracy and range) for a 3D imaging application.展开更多
OBJECTIVE To explore the inhibition of ACHN cells via shRNAexpression vector mediated cyclinE1 gene silencing.METHODS The shRNA targeting at cyclinE1 gene was designedand synthesized. By ligation, the fragment was ins...OBJECTIVE To explore the inhibition of ACHN cells via shRNAexpression vector mediated cyclinE1 gene silencing.METHODS The shRNA targeting at cyclinE1 gene was designedand synthesized. By ligation, the fragment was inserted intopGenesil-1-U6 to construct the recombinant plasmid pGenesil-1-U6-cyclinE1. The identified recombinant plasmid was introducedinto ACHN cells with lipofectamine 2000. The inhibition ofcyclinE1 mRNA and protein expression were analyzed by RT-PCRand western-blotting. MTT method was used for observing cellproliferation and drawing growth curve. The cell cycle and ratiosof apoptotic cell were assessed by flow cytometric detection. Theability of invasion and speed of cell migration were detected bytranswell chamber invasive models and cell scratch method.RESULTS The inhibition of expression of cyclinE1 in ACHN cellsmediated by recombinant vector (0.0933 ± 0.05) was significantlylower than that in the group of transfected with empty vector(0.8827 ± 0.04) and the control group (0.9021 ± 0.03) (P < 0.05).Flow cytometry showed that recombinant cells were blocked inthe G_1 phase and the apoptotic ratio was increased significantly(11.15 ± 4.00)% (P < 0.05). The curves of cell growth indicated thatthe proliferation of cell transfected with recombinant plasmid wasinhibited significantly compared with that in control group (P <0.05). The results of transwell and cell scratch suggested that theabilities of invasion and migration of the cells transfected withrecombinant plasmid were decreased conspicuously (P < 0.05).CONCLUSION The expression of cyclinE1 could be inhibitedsuccessfully by RNA interference induced by shRNA expressionvector. This consequently inhibits the cell growth and inducesapoptosis. Our study provided a preliminary result in searching ofRNA interference (RNAi) therapy for renal cell carcinoma.展开更多
Experimental investigations were conducted in this study to explore the effect of magnetization on water sample properties and to envisage whether the effect is beneficial for mercury detection in a sample of water or...Experimental investigations were conducted in this study to explore the effect of magnetization on water sample properties and to envisage whether the effect is beneficial for mercury detection in a sample of water or not. Subjecting the water sample to 0.3 Tesla magnetic field for 14 hours led to instantaneous effects on the examined water properties, where a reduction in the values of pH (7%) and interfacial tension (0.2%) was observed, whereas an increase (8%) in water electrical conductivity was recorded. Similar behaviours with slight changes in trend were observed after storing the samples for six days, which indicates a creation of permanent effects. Other experiments were conducted to explore the impact of magnetizing water sample containing inorganic mercury prior to detection by emission spectroscopy. Samples were prepared with different mercury concentrations and derivatized by using tin chloride (SnCI2). The generated mercury vapour species were transported with aid of carrier gas into a dielectric barrier discharge plasma atomizer, in which the mercury signal at 253.65 nm was recorded. The results have shown 3.5%-7.5% increase in the signal intensities recorded for the magnetized samples, mostly attributed to a reduction in the sample surface tension and other reasons, which facilitates analyte derivatization.展开更多
The Torgiovannetto quarry(Assisi municipality,central Italy) is an example of a site where the natural equilibrium was altered by human activity,causing current slope instability phenomena which threaten two roadways ...The Torgiovannetto quarry(Assisi municipality,central Italy) is an example of a site where the natural equilibrium was altered by human activity,causing current slope instability phenomena which threaten two roadways important for the local transportation.The quarry front,having a height of about 140 m,is affected by a 182,000 m3 rockslide developed in intensely fractured limestone and is too large to be stabilized.In 2003 some tension cracks were detected in the vegetated area above the quarry upper sector.From then on,several monitoring campaigns were carried out by means of different instrumentations(topographic total station,extensometers,inclinometers,ground-based interferometric radar,laser scanner and infrared thermal camera),allowing researchers to accurately define the landslide area and volume.The latter's major displacements are localized in the eastern sector.The deformational field appears to be related to the seasonal rainfall.The landslide hazard associated with the worst case scenario was evaluated in terms of magnitude,intensity and triggering mechanism.For the definition of the possible runout process the DAN 3D code was employed.The simulation results were used in order to design and construct a retaining embankment.Furthermore,in order to preserve both the safety of the personnelinvolved in its realization and of the roadways users,an early warning system was implemented.The early warning system is based on daily-averaged displacement velocity thresholds.The alarm level is reached if the prediction based on the methods of Saito(1969) and Fukuzono(1985) forecasts an imminent rupture.展开更多
文摘This paper describes a technology of dynamic display moving image by computer monitor,which is initially used in the design of tool detection system. The paper presents the hardware and software principie and edge detection process. The way of marking edge point coordinates and stability of moving image also is analyzed. The method reforms the conventional design of the 2-D vision detection system. Moreover,it facilitates the design of the systematic mechanical construction,is convenient to compile instrument systemsoftware,and realizes to detect and track display image simultaneously. By the work,the tool detection system is improved to practical application.
文摘Testing methods of instrumental system in the marine magnetic survey have been studied in this paper, and the feasibility of each method has been testified by the observed data. The conclusion shows that the method brought out can effectively eliminate the systematic error caused by the instrumental system, and greatly improve the surveying precision and the reliability of the survey results.
基金National Natural Science Foundation of China(No.61302159,61227003,61301259)Natural Science Foundation of Shanxi Province(No.2012021011-2)The Project Sponsored by Scientific Research for the Returned Overseas Chinese Scholars,Shanxi Province(No.2013-083)
文摘In order to detect and process underground vibration signal, this paper presents a system with the combination of software and hardware. The hardware part consists of sensor, memory chips, USB, etc. , which is responsible for capturing original signals from sensors. The software part is a virtual oscilloscope based on LabWindows/CVI (C vitual instrument), which not only has the functions of traditional oscilloscope but also can analyze and process vibration signals in special ways. The experimental results show that the designed system is stable, reliable and easy to be operated, which can meet practical requirements.
文摘Aim The several species of the genus Paris called "Chonglou" are famous traditional Chinese herbal medicines. We established the quantitative analysis method of the steroidal saponins in some species of the genus Paris and discussed their relations. Methods We detected the contents of 11 steroidal saponins in Paris samples with a Kromasel C18 ( 150 mm× 4.6 mm ID, 5μm) column which was subjected to gradient elution with acetonitrile-water (30:70- 60:40, V/V) at a flow rate of 1 mL· min^-1 by HPLC-ELSD and established chemical cluster tree using SPSS 11 software. Results All the samples could be separated and calibration curves of 11 saponins were prepared. We successfully detected the contents of 11 steroidal saponins in 14 Paris spp. in 30 min. The recovery for the assay of saponins was between 95 % and 97 %. The RSD of precision of 11 saponins and stability of samples were below 3 %. Chemical phylogenetic tree based on saponin contents indicated that 17 samples of Paris spp. clustered separately. Conclusion The established method is accurate and convenient, and suitable for the quantitative analysis of these 11 steroidal saponins in Paris spp.. The chemical phylogenetic tree is in accordance with Takhtajian classical taxonomy.
基金The National High Technology Research and Development Program of China (863Program)(No.2002AA812038)the National Defense Pre-Research Support Program (No.41308050109)
文摘A novel closed-loop control strategy of a silicon microgyroscope (SMG) is proposed. The SMG is sealed in metal can package in drive and sense modes and works under the air pressure of 10 Pa. Its quality factor reaches greater than l0 000. Self-oscillating and closed-loop methods based on electrostatic force feedback are adopted in both measure and control circuits. Both single side driving and sensing methods are used to simplify the drive circuit. These dual channel decomposition and reconstruction closed loops are applied in sense modes. The testing results demonstrate that useful signals and guadrature signals do not interact with each other because of the decoupling of their phases. Under the condition of a scale factor of 9. 6 mV/((°) .s), in a full measurement range of±300 (°)/s, the zero bias stability reaches 28 (°)/h with a nonlinear coefficient of 400 × 10^-6 and a simulated bandwidth of more than 100 Hz. The overall performance is improved by two orders of magnitude in comparison to that at atmospheric pressure.
文摘AIM:To investigate the inhibitory effect of acetylshikonin on human gastric carcinoma cell line SGC-7901 and its mechanism. METHODS:MTT assay was used to assess the inhibitory effect of acetylshikonin on proliferation of SGC-7901 cells.Apopt osis-inducing effect was determined by flow cytometry and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling with Hoechst staining.Expression of mRNA and protein in Bcl-2 and Bax was analyzed by reverse transcription-polymerase chain reaction and Western blot.Antitumor effect of acetylshikonin on a mouse SGC-7901 model was also determined. RESULTS:Forty-eight hours after treatment with acetylshikonin,MTT assay showed that acetylshikonin inhibited the proliferation of SGC-7901 cells in a dose-dependent manner.The half maximal inhibitory concentration of acetylshikonin to SGC-7901 cells was 0.428±0.07 mg/L.Cell shrinkage,nuclear pyknosis and chromatin condensation,which are the characteristics of cell apoptosis,were observed in treated SGC-7901 cells and the percentage of apoptosis increased in a dose-dependent manner.Acetylshikonin downregulated the expression of Bcl-2 and up-regulated the expression of Bax in the treated SGC-7901 cells compared with the controls.The experiment in vivo showed that 0.5,1,and 2 mg/kg of acetylshikonin significantly inhibited the growth of tumor in the mouse SGC-7901 model,with an inhibitory rate of 25.00%-55.76%. CONCLUSION:Acetylshikonin inhibits the growth of SGC-7901 cells in vitro and in vivo by inducing cell apoptosis.
基金supported by the Korea Research Foundation Grant funded by the Korean Government(MOEHRD),the MKE(The Ministry of Knowledge Economy,Korea)the ITRC(Information Technology Research Center)support program(NIPA-2009-(C1090-0902-0007))
文摘Vehicle detectition in still images is a comparatively difficult task. This paper presents a method for this task by using boosted local pattern detector constructed from two local features including Haar-like and oriented gradient features. The whole process is composed of three stages. In the first stage, local appearance features of vehicles and non-vehicle objects are extracted. Haar-tike and oriented gradient features are extracted separately in this stage as local features. In the second stage, Adabeost algorithm is used to select the most discriminative features as weak detectors from the two local feature sets, and a strong local pattern detector is built by the weighted combination of these selected weak detectors. Finally, vehicle detection can be performed in still images by using the boosted strong local feature detector. Experiment results show that the local pattern detector constructed in this way combines the advantages of Haar-like and oriented gradient features, and can achieve better detection results than the detector by using single Haar-like features.
基金Project(2017YFC0805307) supported by the National Key Research and Development Program of ChinaProjects(51878078, 51927814, 51911530215) supported by the National Natural Science Foundation of China+4 种基金Project(2018-025) supported by the Training Program for High-level Technical Personnel in Transportation Industry, ChinaProject (2018JJ1026) supported by the Excellent Youth Foundation of Natural Science Foundation of Hunan Province, ChinaProject(17A008) supported by the Key Project of Education Department of Hunan Province, ChinaProjects(kfj150103, kfj170104) supported by the Open Research Fund of State Engineering Laboratory of Highway Maintenance Technology, Changsha University of Science & Technology, ChinaProject(CX20190644) supported by the Postgraduate Scientific Research Innovation Project of Hunan Province, China。
文摘To relieve the increasing traffic load, many early built highways need to be widened or reconstructed. The rapid performance detection to existing subgrades is important to their reasonable evaluation and maximized utilization. Based on five kinds of soils taken from an existing highway in southern China, three commonly detecting methods were used to determine their moisture contents, compaction degrees and resilient moduli. The results showed that the measured moisture contents were greater than the design value, and the compaction degrees decreased sharply compared to the original ones. The moisture and heat exchange produced a decrease in the resilient modulus of plate loading test(PLT) from the standard 60 MPa down to 40 MPa. Afterwards, the portable falling weight deflectometer(PFWD) and dynamic cone penetrometer(DCP) were used to evaluate the subgrade performances. The measured PFWD moduli and the DCP penetration rates were correlated with the resilient moduli of PLT, deflections of the Beckman beam test, compaction degrees and moisture contents. The correlation analysis indicates that both of two methods are suitable in rapid detecting subgrade performances, but PFWD method is more recommended for it has higher accuracy and efficiency.
文摘AIM: To investigate if high-definition (HD) colonoscope with i-Scan gave a higher detection rate of mucosal le- sions vs standard white-light instruments. METHODS: Data were collected from the computer- ized database of the endoscopy unit of our tertiary referral center. We retrospectively analyzed 1101 con- secutive colonoscopies that were performed over 1 year with standard white-light (n = 849) or HD+ with i-Scan (n = 252) instruments by four endoscopists, in an outpatient setting. Colonoscopy records included patients' main details and family history for colorectal cancer, indication for colonoscopy (screening, diagnos- tic or surveillance), type of instrument used (standard white-light or HD+ plus i-Scan), name of endoscopist and bowel preparation. Records for each procedure included whether the cecum was reached or not and the reason for failure, complications during or imme- diately after the procedure, and number, size, location and characteristics of the lesions. Polyps or protruding lesions were defined as sessile or pedunculated, and nonprotruding lesions were defined according to Paris classification. For each lesion, histological diagnosis was recorded. RESULTS: Eight hundred and forty-nine colonosco- pies were carried with the standard white-light video colonoscope and 252 with the HD+ plus i-Scan video colonoscope, The four endoscopists did 264, 300, 276 and 261 procedures, respectively; 21.6%, 24.0%, 21.7% and 24.1% of them with the HD+ plus i-Scan technique. There were no significant differences be- tween the four endoscopists in either the number of procedures done or the proportions of each imaging technique used. Both techniques detected one or more mucosal lesions in 522/1101 procedures (47.4%). The overall number of lesions recognized was 1266; 645 in the right colon and 621 in the left. A significantly higher number of colonoscopies recognized lesions in the HD+ plus i-Scan mode (171/252 = 67.9%) than with the standard white-light technique (408/849 = 48.1%) (P 〈 0.0001). HD+ with i-Scan colonoscopies identified more lesions than standard white-light imag- ing (459/252 and 807/849, P 〈 0.0001), in the right or left colon (mean :1: SD, 1.62±1.36 vs 1.33±0.73, P 〈 0.003 and 1.55±0.98 vs 1.17±0.93, P = 0.033), more lesions 〈 10 mm (P 〈 0.0001) or nonprotruding (P 〈 0.022), and flat polyps (P = 0.04). The cumulative mean number of lesions per procedure detected by the four endoscopists was significantly higher with HD+ with i-Scan than with standard white-light imaging (1.82 ± 2.89 vs 0.95± 1.35, P 〈 0.0001). CONCLUSION: HD imaging with i-Scan during the withdrawal phase of colonoscopy significantly increased the detection of colonic mucosal lesions, particularly small and nonprotruding polyps.
文摘Objective: To observe the expression of CD13/APN in peripheral blood lymphocytes and skin lesions of patients with advanced psoriasis vulgaris, and discuss its effect on the pathogenesis of psoriasis. Methods: CD 13 expression in peripheral blood lymphocytes and skin lesions was detected by flow cytometry and imrnunohistochemical technique, respectively. Results were compared with those of healthy controls. Results: CD 13 expression was significantly higher in peripheral blood lymphocytes of patients with advanced psoriasis vulgaris than in that of healthy controls, and in skin lesions than in healthy skin tissues. The expression was mainly in the suprabasal layers of skin lesions, and positively correlated to PASI (R 0.78029). Conclusion: The significantly higher expression of CD13 in peripheral blood lymphocytes and skin lesions of the patients with advanced psoriasis vulgaris probably is related to immunological abnormality, blood vessel abnormality and proliferation of keratinocyte in the pathogenic course of psoriasis. It may be a novel and effective way to treat psoriasis with specific CD13 inhibitors.
文摘Luster is one of the main factors in assessing fabric appearance. There are many different ways to definite and describe the luster, which result in disorder and discommodious in evaluation. Based on previous work, an apparatus suited for the measure of lustre is developed. Which performed measure the reflection distribution of fabrics automatically. Then the objective judgment can be given by the geniophotometric curve. Finally taking several kind of specimens for example give the results to prove the effectiveness of the device.
基金National Natural Science Foundation of Tianjin(08JCYBJC14700)
文摘A design for low power consumption inspection instrument, in which the ATMega32L is used as the control core, is presented. The reader with wireless identification based on RF technology is researched and the low-cost power is studied particularly. This instrument can be used in industry fields to measure temperature, humidity, gas concentration and other specifications, so it has wide applications and is worth to be extended.
文摘Initially studied and developed by students in universities, the very small pico satellites (with a mass lower than 1 kg) are more and more considered for science applications. In particular, there are plans to use them in constellations of small spacecraft for remote sensing of various regions of the magnetosphere. They require a payload with specific size, weight and power consumption. In order to respond to this demand, new instruments have to be developed. Those instruments should exhibit at least the same performances as those used in larger satellites while fulfilling the specific requirements imposed by the satellites size. For this reason, the authors currently develop a xylophone bar magnetometer (XBM) based on micro-electromechanical systems (MEMS) with integrated detector electronics. The principle of this magnetometer is based on a classical resonating xylophone bar. A sinnsoidal current oscillating at the fundamental bending resonant frequency of the bar is applied through the device, and when an external magnetic field is present, the resulting Lorentz force yields the bar to vibrate at its fundamental mode with a displacement directly proportional to the amplitude in one direction of the ambient magnetic field. When designing a MEMS XBM, the detection method is a crucial aspect. The measurement method largely influences the geometry of the magnetometer as well as the manufacturing technology. Due to the constraints in terms of size, weight and power consumption, the two most promising measurement methods are capacitive and piezoelectric ones. Several designs including these measurement techniques are presented and simulated under realistic conditions. First, designs including lateral electrodes for capacitive measurement are tackled based on Silicon-On-Insulator (SOI) process. For the piezoelectric detection, a new configuration based on Lead Zirconate Titanate (PZT)/Pt structure is introduced and leads to much better sensitivity than the traditional Pt/PZT/Pt sandwich structure. Finally, the principle of electronic circuits enabling high sensitivity and low power consumption are proposed.
文摘Background:Stiffness is commonly assessed in relation to injury and athletic performance.The purpose of this research was to compare the validity and reliability of 3 in vivo methods of stiffness assessment using 1 cohort of participants.Methods:To determine inter-day reliability,15 female netballers were assessed for stiffness twice within 1 week using unilateral hopping(vertical stiffness),free oscillations of the calf,and myometry of various muscles of the triceps surae.To establish convergent construct validity,stiffness was compared to static and dynamic strength measurements.Results:Test–retest stiffness results revealed that vertical stiffness produced moderate to high reliability results and myometry presented moderate to very high reliability.In contrast,the free oscillation technique displayed low to moderate reliability.Vertical stiffness demonstrated a significa t correlation with rate of force development during a squat jump,whilst myometer stiffness measurements from 3 sites in the lower limb revealed significan correlations with isometric rate of force development.Further,significan negative correlations were evident between the eccentric utilisation ratio and various myometer stiffness results.No relationships were established between the free oscillation technique and any of the performance measurements.Conclusion:These results suggest that vertical stiffness and myometry are valid and reliable methods for assessing stiffness.
文摘An ion mobility spectrometer equipped with a laser ionization source is used for the sensitive detection of benzene.Mobility spectra of the benzene are presented.We also discussed the mobility spectra at various concentrations and drift voltages.Detection limits are determined to be in the upper ppb_v range.In the end,the advantages and possibilities of this technique are briefly discussed.
文摘In this article the problem of three-dimensional (3-D) reconstruction of scenes from terrestrial laser rangefinder data is processed, we present the simulations results of radiometric range function of the laser range finder imaging system for better optimization of maximum range detection with a given SNR (Signal-to-noise ratio). The study proposes a new reformulation of the radiometric Gaussian beam range equation on the basis of the photodetector active area. The adjustment of the optical and geometrical characteristics of the laser range finder so defined can be used to minimize the signal span to avoid the saturation of the detector cell and improve the ranging measurements (accuracy and range) for a 3D imaging application.
基金supported by a grant from Major State Basic Research Development Program,China(No.2002CB513107).
文摘OBJECTIVE To explore the inhibition of ACHN cells via shRNAexpression vector mediated cyclinE1 gene silencing.METHODS The shRNA targeting at cyclinE1 gene was designedand synthesized. By ligation, the fragment was inserted intopGenesil-1-U6 to construct the recombinant plasmid pGenesil-1-U6-cyclinE1. The identified recombinant plasmid was introducedinto ACHN cells with lipofectamine 2000. The inhibition ofcyclinE1 mRNA and protein expression were analyzed by RT-PCRand western-blotting. MTT method was used for observing cellproliferation and drawing growth curve. The cell cycle and ratiosof apoptotic cell were assessed by flow cytometric detection. Theability of invasion and speed of cell migration were detected bytranswell chamber invasive models and cell scratch method.RESULTS The inhibition of expression of cyclinE1 in ACHN cellsmediated by recombinant vector (0.0933 ± 0.05) was significantlylower than that in the group of transfected with empty vector(0.8827 ± 0.04) and the control group (0.9021 ± 0.03) (P < 0.05).Flow cytometry showed that recombinant cells were blocked inthe G_1 phase and the apoptotic ratio was increased significantly(11.15 ± 4.00)% (P < 0.05). The curves of cell growth indicated thatthe proliferation of cell transfected with recombinant plasmid wasinhibited significantly compared with that in control group (P <0.05). The results of transwell and cell scratch suggested that theabilities of invasion and migration of the cells transfected withrecombinant plasmid were decreased conspicuously (P < 0.05).CONCLUSION The expression of cyclinE1 could be inhibitedsuccessfully by RNA interference induced by shRNA expressionvector. This consequently inhibits the cell growth and inducesapoptosis. Our study provided a preliminary result in searching ofRNA interference (RNAi) therapy for renal cell carcinoma.
文摘Experimental investigations were conducted in this study to explore the effect of magnetization on water sample properties and to envisage whether the effect is beneficial for mercury detection in a sample of water or not. Subjecting the water sample to 0.3 Tesla magnetic field for 14 hours led to instantaneous effects on the examined water properties, where a reduction in the values of pH (7%) and interfacial tension (0.2%) was observed, whereas an increase (8%) in water electrical conductivity was recorded. Similar behaviours with slight changes in trend were observed after storing the samples for six days, which indicates a creation of permanent effects. Other experiments were conducted to explore the impact of magnetizing water sample containing inorganic mercury prior to detection by emission spectroscopy. Samples were prepared with different mercury concentrations and derivatized by using tin chloride (SnCI2). The generated mercury vapour species were transported with aid of carrier gas into a dielectric barrier discharge plasma atomizer, in which the mercury signal at 253.65 nm was recorded. The results have shown 3.5%-7.5% increase in the signal intensities recorded for the magnetized samples, mostly attributed to a reduction in the sample surface tension and other reasons, which facilitates analyte derivatization.
基金the National Department of Civil Protection, the Perugia Province and the Umbria Region for funding the work behind this research
文摘The Torgiovannetto quarry(Assisi municipality,central Italy) is an example of a site where the natural equilibrium was altered by human activity,causing current slope instability phenomena which threaten two roadways important for the local transportation.The quarry front,having a height of about 140 m,is affected by a 182,000 m3 rockslide developed in intensely fractured limestone and is too large to be stabilized.In 2003 some tension cracks were detected in the vegetated area above the quarry upper sector.From then on,several monitoring campaigns were carried out by means of different instrumentations(topographic total station,extensometers,inclinometers,ground-based interferometric radar,laser scanner and infrared thermal camera),allowing researchers to accurately define the landslide area and volume.The latter's major displacements are localized in the eastern sector.The deformational field appears to be related to the seasonal rainfall.The landslide hazard associated with the worst case scenario was evaluated in terms of magnitude,intensity and triggering mechanism.For the definition of the possible runout process the DAN 3D code was employed.The simulation results were used in order to design and construct a retaining embankment.Furthermore,in order to preserve both the safety of the personnelinvolved in its realization and of the roadways users,an early warning system was implemented.The early warning system is based on daily-averaged displacement velocity thresholds.The alarm level is reached if the prediction based on the methods of Saito(1969) and Fukuzono(1985) forecasts an imminent rupture.