To segment the tumor region precisely is a prerequisite for ultrasound navigation and treatment. In this paper, a normalized cut method to segment tumor ultrasound image is proposed by means of simple linear iterative...To segment the tumor region precisely is a prerequisite for ultrasound navigation and treatment. In this paper, a normalized cut method to segment tumor ultrasound image is proposed by means of simple linear iterative clustering for presegmentation procedure. The first step, we use simple linear iterative clustering algorithm to divide the image into a number of homogeneous over-segmented regions. Then, these regions are regarded as nodes, and a similarity matrix is constructed by comparing the histograms of each two regions. Finally, we apply the Ncut method to merging the over-segmented regions, then the image segmentation process is completed. The results show that the proposed segmentation scheme handles the strong speckle noise, low contrast, and weak edges well in ultrasound image. Our method has high segmentation precision and computation efficiency than the pixel-based Ncut method.展开更多
[Objectives] The research aimed to extract green pigment from leaves of Arctium lappa L. and inspect its stability. [Methods] Ultrasound assisted method was used. [Results] Water bath temperature had little impact on ...[Objectives] The research aimed to extract green pigment from leaves of Arctium lappa L. and inspect its stability. [Methods] Ultrasound assisted method was used. [Results] Water bath temperature had little impact on green pigment, and Al^(3+), Cu^(2+), Mg^(2+) and Zn^(2+) in metal ions greatly affected green pigment, while Fe^(3+) had very little impact on the stability of green pigment. pH did not basically affect green pigment of A. lappa L. [Conclusions] The extraction rate and stability of green pigment from leaves of A. lappa L. were higher, and it was one of materials suitable for extracting green pigment.展开更多
AIM To evaluate the efficacy of endoscopic ultrasoundguided fine needle aspiration(EUS-FNA) of pancreatic head cancer when pushing(push method) or pulling the echoendoscope(pull method).METHODS Overall, 566 pancreatic...AIM To evaluate the efficacy of endoscopic ultrasoundguided fine needle aspiration(EUS-FNA) of pancreatic head cancer when pushing(push method) or pulling the echoendoscope(pull method).METHODS Overall, 566 pancreatic cancer patients had their first EUS-FNA between February 2001 and December 2017. Among them, 201 who underwent EUS-FNA for pancreatic head lesions were included in this study. EUS-FNA was performed by the push method in 85 patients, the pull method in 101 patients and both the push and pull methods in 15 patients. After propensity score matching(age, sex, tumor diameter, and FNA needle), 85 patients each were stratified into the push and pull groups. Patient characteristics and EUSFNA-related factors were compared between the two groups.RESULTS Patient characteristics were not significantly different between the two groups. The distance to lesion was significantly longer in the push group than in the pull group(13.9 ± 4.9 mm vs 7.0 ± 4.9 mm, P < 0.01). The push method was a significant factor influencing the distance to lesion(≥ median 10 mm)(P < 0.01). Additionally, tumor diameter ≥ 25 mm(OR = 1.91, 95%CI: 1.02-3.58, P = 0.043) and the push method(OR = 1.91, 95%CI: 1.03-3.55, P = 0.04) were significant factors contributing to the histological diagnosis of malignancy.CONCLUSION The pull method shortened the distance between the endoscope and the lesion and facilitated EUS-FNA of pancreatic head cancer. The push method contributed to the histological diagnosis of pancreatic head cancer using EUS-FNA specimens.展开更多
OBJECTIVE: To compare the clinical effect of brachial plexus block with "One Injection Two Points" guided under ultrasound and the conventional method guiding by ultrasound. METHODS: 70 patients were randomi...OBJECTIVE: To compare the clinical effect of brachial plexus block with "One Injection Two Points" guided under ultrasound and the conventional method guiding by ultrasound. METHODS: 70 patients were randomized evenly into 2 groups, with 35 patients in each group, while the Experiment Group(Group B) received One Injection Two Points" method, the Control Group(Group A) received the conventional method.The nerve block every 5 s, the success rate of anesthesia, the dosage of local anesthetics, second remedial anesthesia, adverse reactions, etc.were recorded. RESULTS: Group B was superior to group A in the success rate of anesthesia; There were 6 patients in group A who required constant pump injection of Remifentanil to remedy, while no patients in Group B needed remedy treatment. There were no serious adverse reactions in both groups.CONCLUSIONS: The clinical effect of brachial plexus block with "One Injection Two Points" method guided under ultrasoundguiding by ultrasound was superior to that of the conventional method.展开更多
In this study, five 2 -4 years old healthy female poodles were selected and mated after spontaneous estrus for pregnancy diagnosis with external observa- tion, human chorionic gonadotropin colloidal gold rapid test st...In this study, five 2 -4 years old healthy female poodles were selected and mated after spontaneous estrus for pregnancy diagnosis with external observa- tion, human chorionic gonadotropin colloidal gold rapid test strips （human early pregnancy test strips）, ultrasonic diagnosis and blood routine examination. Accord- ing to the results, female dogs showed abdominal circumference increment and mammogenesis from a month post-mating to parturition and lactated before parturi- tion. At 5, 6, 7, 15, 25 and 35 d post-mating, pregnancy diagnosis with human chorionic gonadotropin colloidal gold rapid test strips showed negative results. Hu- man early pregnancy test strips can not be used for pregnancy diagnosis in female dogs. Currently, ultrasonic method is the most accurate method to diagnose preg- nancy in female dogs, and the optimal diagnosis time is the 30th d post-mating. External observation and blood routine examination can be used as auxiliary methods to diagnose pregnancy in female dogs.展开更多
Effective prevention and management of osteoporosis would require suitable methods for population screenings and early diagnosis. Current clinicallyavailable diagnostic methods are mainly based on the use of either X-...Effective prevention and management of osteoporosis would require suitable methods for population screenings and early diagnosis. Current clinicallyavailable diagnostic methods are mainly based on the use of either X-rays or ultrasound(US). All X-ray based methods provide a measure of bone mineral density(BMD), but it has been demonstrated that other structural aspects of the bone are important in determining fracture risk, such as mechanical features and elastic properties, which cannot be assessed using densitometric techniques. Among the most commonly used techniques, dual X-ray absorptiometry(DXA) is considered the current 'gold standard' for osteoporosis diagnosis and fracture risk prediction. Unfortunately, as other X-ray based techniques, DXA has specific limitations(e.g., use of ionizing radiation, large size of the equipment, high costs, limited availability) that hinder its application for population screenings and primary care diagnosis. This has resulted in an increasing interest in developing reliable pre-screening tools for osteoporosis such as quantitative ultrasound(QUS) scanners, which do not involve ionizing radiation exposure and represent a cheaper solution exploiting portable and widely available devices. Furthermore, the usefulness of QUS techniques in fracture risk prediction has been proven and, with the last developments, they are also becoming a more and more reliable approach for assessing bone quality. However, the US assessment of osteoporosis is currently used only as a pre-screening tool, requiring a subsequent diagnosis confirmation by means of a DXA evaluation. Here we illustrate the state of art in the early diagnosis of this 'silent disease' and show up recent advances for its prevention and improved management through early diagnosis.展开更多
BACKGROUND For palliation of malignant biliary obstruction(MBO), the gold-standard method of biliary drainage is endoscopic retrograde cholangiopancreatography(ERCP)with the placement of metallic stents. Endoscopic ul...BACKGROUND For palliation of malignant biliary obstruction(MBO), the gold-standard method of biliary drainage is endoscopic retrograde cholangiopancreatography(ERCP)with the placement of metallic stents. Endoscopic ultrasound(EUS)-guided drainage is an alternative that is typically reserved for cases of ERCP failure.Recently, however, there have been robust randomized clinical trials(RCTs)comparing EUS-guided drainage and ERCP as primary approaches to MBO.AIM To compare EUS guidance and ERCP in terms of their effectiveness and safety in palliative biliary drainage for MBO.METHODS This was a systematic review and meta-analysis, in which we searched the MEDLINE, Excerpta Medica, and Cochrane Central Register of Controlled Trials databases. Only RCTs comparing EUS and ERCP for primary drainage of MBO were eligible. All of the studies selected provided data regarding the rates of technical and clinical success, as well as the duration of the procedure, adverse events, and stent patency. We assessed the risk of biases using the Jadad score and the quality of evidence using the Grading of Recommendations Assessment,Development and Evaluation criteria.RESULTS The database searches yielded 5920 records, from which we selected 3 RCTs involving a total of 222 patients(112 submitted to EUS and 110 submitted to ERCP). In the EUS and ERCP groups, the rate of technical success was 91.96%n and 91.81%, respectively, with a risk difference(RD) of 0.00%(95%CI:-0.07, 0.07;P = 0.97; I^2 = 0%). The clinical success was 84.81% and 85.53% in the EUS and ERCP groups, respectively, with an RD of-0.01%(95%CI:-0.12, 0.10; P = 0.90; I^2 =0%). The mean difference(MD) for the duration of the procedure was-0.12%(95%CI:-8.20, 7.97; P = 0.98; I^2 = 84%). In the EUS and ERCP groups, there were14 and 25 adverse events, respectively, with an RD of-0.06%(95%CI:-0.23, 0.12; P= 0.54; I^2 = 77%). The MD for stent patency was 9.32%(95%CI:-4.53, 23.18; P =0.19; I^2 = 44%). The stent dysfunction rate was significantly lower in the EUS t group(MD =-0.22%; 95 CI:-0.35,-0.08; P = 0.001; I^2 = 0%).CONCLUSION EUS represents an interesting alternative to ERCP for MBO drainage,demonstrating lower stent dysfunction rates compared with ERCP. Technical and clinical success, duration, adverse events and patency rates were similar.展开更多
Enzymes play essential roles in the biological processes of sludge treatment. In this article, the ultrasound method to extract enzymes from sludge flocs was presented. Results showed that using ultrasound method at 2...Enzymes play essential roles in the biological processes of sludge treatment. In this article, the ultrasound method to extract enzymes from sludge flocs was presented. Results showed that using ultrasound method at 20 kHz could extract more types of enzymes than that at 40 kHz and ethylenediamine tetraacetic acid （EDTA） methods. The optimum parameters of ultrasound extraction at 20 kHz were duration of 10 min and intensity of 552 W/g TSS. Under the optimum condition, ultrasound could break the cells and extract both the extracellular and a small part of intercellular enzymes. Ultrasound intensity was apparently more susceptive to enzyme extraction than duration, suggesting that the control of intensity during ultrasound extraction was more important than that of duration. The Pearson correlation analysis between enzyme activities and cation contents revealed that the different types of enzymes had distinct cation binding characteristics.展开更多
Based on a previous research of cavitation effect under bi-frequency ultrasound irradiation, this paper studies bi-frequency irradiations with similar experimental settings. The additional irradiation sources with fre...Based on a previous research of cavitation effect under bi-frequency ultrasound irradiation, this paper studies bi-frequency irradiations with similar experimental settings. The additional irradiation sources with frequencies of 1.04MHz, 0.8MHz and 1.7MHz are individually combined with the main ultrasonic irradiation source with frequency of 28kHz to form bi-frequency ultrasonic irradiation. The intensity of 28kHz irradiation was fixed at 12.5W/cm^2, while the intensity of the ultrasound at the other three frequencies is varied from1 W/cm^2 to 18 W/cm^2. It turns out that under the influence of the bi-frequency irradiation, the fluorescence intensity is obviously greater than the sum of those at individual frequencies. So the frequency of the additional sonication strikingly influences the fluorescence enhancement effect. For example, the fluorescence enhancement effect of 1.04MHz is stronger than that of 1.7MHz, and the enhancement effect of 0.8MHz is further stronger than that of 1.04MHz. Under the sonic intensity of (7.9)W/cm^2, the fluorescence intensity of 1.04MHz is approximately twice that of 1.7MHz while the fluorescence intensity of 0.8MHz is approximately 1.5 times that of 1.04MHz.展开更多
[Objectives] To optimize the extraction of total flavone in folium Ginkgo biloba leaves.[Methods] Using the ultrasonic extraction method, the three levels of maximum impact were selected by each factor selection, and ...[Objectives] To optimize the extraction of total flavone in folium Ginkgo biloba leaves.[Methods] Using the ultrasonic extraction method, the three levels of maximum impact were selected by each factor selection, and the optimal extraction technology was obtained by box-benhnken test design analysis.[Results] After analyzing the results, the optimal process was as follows: a time of 28.89 min and liquid/material ratio of 31.38∶ 1, the temperature was 40.74℃. In this way, NaNO 2-Al (NO 3) 3-NaOH was used as color developing agent, and the theoretical extraction of flavone in ginkgo leaf can reach 11.74 mg/g.[Conclusions] This method can be used to extract total flavonoids from G. biloba leaves with simple operation, low cost and good repeatability.展开更多
A novel technique for reducing reverberation artifact in acoustic shadow imaging using nonlinear ultrasound interaction, called nonlinear acoustic shadow method, has been developed and experimentally studied. In this ...A novel technique for reducing reverberation artifact in acoustic shadow imaging using nonlinear ultrasound interaction, called nonlinear acoustic shadow method, has been developed and experimentally studied. In this technique, the conventional acoustic shadow method is modified by using the secondary wave generated by nonlinear interaction of two primary sound waves emitted from parametric array. Either conventional or nonlinear acoustic shadow imaging is carried out for aluminum square cylinder and the size of the shadow is compared. The result shows that the nonlinear acoustic shadow method reduces reverberation artifact inside the square cylinder and has better accuracy in the size measurement than conventional acoustic shadow method.展开更多
基金Supported by the National Basic Research Program ofChina(2011CB707900)
文摘To segment the tumor region precisely is a prerequisite for ultrasound navigation and treatment. In this paper, a normalized cut method to segment tumor ultrasound image is proposed by means of simple linear iterative clustering for presegmentation procedure. The first step, we use simple linear iterative clustering algorithm to divide the image into a number of homogeneous over-segmented regions. Then, these regions are regarded as nodes, and a similarity matrix is constructed by comparing the histograms of each two regions. Finally, we apply the Ncut method to merging the over-segmented regions, then the image segmentation process is completed. The results show that the proposed segmentation scheme handles the strong speckle noise, low contrast, and weak edges well in ultrasound image. Our method has high segmentation precision and computation efficiency than the pixel-based Ncut method.
基金Supported by the National Key Research and Development Program of China during the 13th Five-Year Plan Period(2018ZX09301060)Science and Technology Plan Project of Sichuan Province(2016NZYZF0007)the Fourth National Survey of Traditional Chinese Medicine Resources Program(2017)
文摘[Objectives] The research aimed to extract green pigment from leaves of Arctium lappa L. and inspect its stability. [Methods] Ultrasound assisted method was used. [Results] Water bath temperature had little impact on green pigment, and Al^(3+), Cu^(2+), Mg^(2+) and Zn^(2+) in metal ions greatly affected green pigment, while Fe^(3+) had very little impact on the stability of green pigment. pH did not basically affect green pigment of A. lappa L. [Conclusions] The extraction rate and stability of green pigment from leaves of A. lappa L. were higher, and it was one of materials suitable for extracting green pigment.
文摘AIM To evaluate the efficacy of endoscopic ultrasoundguided fine needle aspiration(EUS-FNA) of pancreatic head cancer when pushing(push method) or pulling the echoendoscope(pull method).METHODS Overall, 566 pancreatic cancer patients had their first EUS-FNA between February 2001 and December 2017. Among them, 201 who underwent EUS-FNA for pancreatic head lesions were included in this study. EUS-FNA was performed by the push method in 85 patients, the pull method in 101 patients and both the push and pull methods in 15 patients. After propensity score matching(age, sex, tumor diameter, and FNA needle), 85 patients each were stratified into the push and pull groups. Patient characteristics and EUSFNA-related factors were compared between the two groups.RESULTS Patient characteristics were not significantly different between the two groups. The distance to lesion was significantly longer in the push group than in the pull group(13.9 ± 4.9 mm vs 7.0 ± 4.9 mm, P < 0.01). The push method was a significant factor influencing the distance to lesion(≥ median 10 mm)(P < 0.01). Additionally, tumor diameter ≥ 25 mm(OR = 1.91, 95%CI: 1.02-3.58, P = 0.043) and the push method(OR = 1.91, 95%CI: 1.03-3.55, P = 0.04) were significant factors contributing to the histological diagnosis of malignancy.CONCLUSION The pull method shortened the distance between the endoscope and the lesion and facilitated EUS-FNA of pancreatic head cancer. The push method contributed to the histological diagnosis of pancreatic head cancer using EUS-FNA specimens.
文摘OBJECTIVE: To compare the clinical effect of brachial plexus block with "One Injection Two Points" guided under ultrasound and the conventional method guiding by ultrasound. METHODS: 70 patients were randomized evenly into 2 groups, with 35 patients in each group, while the Experiment Group(Group B) received One Injection Two Points" method, the Control Group(Group A) received the conventional method.The nerve block every 5 s, the success rate of anesthesia, the dosage of local anesthetics, second remedial anesthesia, adverse reactions, etc.were recorded. RESULTS: Group B was superior to group A in the success rate of anesthesia; There were 6 patients in group A who required constant pump injection of Remifentanil to remedy, while no patients in Group B needed remedy treatment. There were no serious adverse reactions in both groups.CONCLUSIONS: The clinical effect of brachial plexus block with "One Injection Two Points" method guided under ultrasoundguiding by ultrasound was superior to that of the conventional method.
基金Supported by Agricultural Project of Taizhou City,Jiangsu Province(TN2013012)College-level Project of Jiangsu Agri-animal Husbandry Voca tional College(NSFYB1305)Innovation Training Program for Students in Colleges and Universities in Jiangsu Province(201312806013Y)
文摘In this study, five 2 -4 years old healthy female poodles were selected and mated after spontaneous estrus for pregnancy diagnosis with external observa- tion, human chorionic gonadotropin colloidal gold rapid test strips （human early pregnancy test strips）, ultrasonic diagnosis and blood routine examination. Accord- ing to the results, female dogs showed abdominal circumference increment and mammogenesis from a month post-mating to parturition and lactated before parturi- tion. At 5, 6, 7, 15, 25 and 35 d post-mating, pregnancy diagnosis with human chorionic gonadotropin colloidal gold rapid test strips showed negative results. Hu- man early pregnancy test strips can not be used for pregnancy diagnosis in female dogs. Currently, ultrasonic method is the most accurate method to diagnose preg- nancy in female dogs, and the optimal diagnosis time is the 30th d post-mating. External observation and blood routine examination can be used as auxiliary methods to diagnose pregnancy in female dogs.
基金Supported by Partially funded by FESR P.O.Apulia Region 2007-2013-Action 1.2.4,No.3Q5AX31
文摘Effective prevention and management of osteoporosis would require suitable methods for population screenings and early diagnosis. Current clinicallyavailable diagnostic methods are mainly based on the use of either X-rays or ultrasound(US). All X-ray based methods provide a measure of bone mineral density(BMD), but it has been demonstrated that other structural aspects of the bone are important in determining fracture risk, such as mechanical features and elastic properties, which cannot be assessed using densitometric techniques. Among the most commonly used techniques, dual X-ray absorptiometry(DXA) is considered the current 'gold standard' for osteoporosis diagnosis and fracture risk prediction. Unfortunately, as other X-ray based techniques, DXA has specific limitations(e.g., use of ionizing radiation, large size of the equipment, high costs, limited availability) that hinder its application for population screenings and primary care diagnosis. This has resulted in an increasing interest in developing reliable pre-screening tools for osteoporosis such as quantitative ultrasound(QUS) scanners, which do not involve ionizing radiation exposure and represent a cheaper solution exploiting portable and widely available devices. Furthermore, the usefulness of QUS techniques in fracture risk prediction has been proven and, with the last developments, they are also becoming a more and more reliable approach for assessing bone quality. However, the US assessment of osteoporosis is currently used only as a pre-screening tool, requiring a subsequent diagnosis confirmation by means of a DXA evaluation. Here we illustrate the state of art in the early diagnosis of this 'silent disease' and show up recent advances for its prevention and improved management through early diagnosis.
文摘BACKGROUND For palliation of malignant biliary obstruction(MBO), the gold-standard method of biliary drainage is endoscopic retrograde cholangiopancreatography(ERCP)with the placement of metallic stents. Endoscopic ultrasound(EUS)-guided drainage is an alternative that is typically reserved for cases of ERCP failure.Recently, however, there have been robust randomized clinical trials(RCTs)comparing EUS-guided drainage and ERCP as primary approaches to MBO.AIM To compare EUS guidance and ERCP in terms of their effectiveness and safety in palliative biliary drainage for MBO.METHODS This was a systematic review and meta-analysis, in which we searched the MEDLINE, Excerpta Medica, and Cochrane Central Register of Controlled Trials databases. Only RCTs comparing EUS and ERCP for primary drainage of MBO were eligible. All of the studies selected provided data regarding the rates of technical and clinical success, as well as the duration of the procedure, adverse events, and stent patency. We assessed the risk of biases using the Jadad score and the quality of evidence using the Grading of Recommendations Assessment,Development and Evaluation criteria.RESULTS The database searches yielded 5920 records, from which we selected 3 RCTs involving a total of 222 patients(112 submitted to EUS and 110 submitted to ERCP). In the EUS and ERCP groups, the rate of technical success was 91.96%n and 91.81%, respectively, with a risk difference(RD) of 0.00%(95%CI:-0.07, 0.07;P = 0.97; I^2 = 0%). The clinical success was 84.81% and 85.53% in the EUS and ERCP groups, respectively, with an RD of-0.01%(95%CI:-0.12, 0.10; P = 0.90; I^2 =0%). The mean difference(MD) for the duration of the procedure was-0.12%(95%CI:-8.20, 7.97; P = 0.98; I^2 = 84%). In the EUS and ERCP groups, there were14 and 25 adverse events, respectively, with an RD of-0.06%(95%CI:-0.23, 0.12; P= 0.54; I^2 = 77%). The MD for stent patency was 9.32%(95%CI:-4.53, 23.18; P =0.19; I^2 = 44%). The stent dysfunction rate was significantly lower in the EUS t group(MD =-0.22%; 95 CI:-0.35,-0.08; P = 0.001; I^2 = 0%).CONCLUSION EUS represents an interesting alternative to ERCP for MBO drainage,demonstrating lower stent dysfunction rates compared with ERCP. Technical and clinical success, duration, adverse events and patency rates were similar.
基金supported by the Hi-Tech Research and Development Program (863) of China (No.2006AA06Z384).
文摘Enzymes play essential roles in the biological processes of sludge treatment. In this article, the ultrasound method to extract enzymes from sludge flocs was presented. Results showed that using ultrasound method at 20 kHz could extract more types of enzymes than that at 40 kHz and ethylenediamine tetraacetic acid （EDTA） methods. The optimum parameters of ultrasound extraction at 20 kHz were duration of 10 min and intensity of 552 W/g TSS. Under the optimum condition, ultrasound could break the cells and extract both the extracellular and a small part of intercellular enzymes. Ultrasound intensity was apparently more susceptive to enzyme extraction than duration, suggesting that the control of intensity during ultrasound extraction was more important than that of duration. The Pearson correlation analysis between enzyme activities and cation contents revealed that the different types of enzymes had distinct cation binding characteristics.
文摘Based on a previous research of cavitation effect under bi-frequency ultrasound irradiation, this paper studies bi-frequency irradiations with similar experimental settings. The additional irradiation sources with frequencies of 1.04MHz, 0.8MHz and 1.7MHz are individually combined with the main ultrasonic irradiation source with frequency of 28kHz to form bi-frequency ultrasonic irradiation. The intensity of 28kHz irradiation was fixed at 12.5W/cm^2, while the intensity of the ultrasound at the other three frequencies is varied from1 W/cm^2 to 18 W/cm^2. It turns out that under the influence of the bi-frequency irradiation, the fluorescence intensity is obviously greater than the sum of those at individual frequencies. So the frequency of the additional sonication strikingly influences the fluorescence enhancement effect. For example, the fluorescence enhancement effect of 1.04MHz is stronger than that of 1.7MHz, and the enhancement effect of 0.8MHz is further stronger than that of 1.04MHz. Under the sonic intensity of (7.9)W/cm^2, the fluorescence intensity of 1.04MHz is approximately twice that of 1.7MHz while the fluorescence intensity of 0.8MHz is approximately 1.5 times that of 1.04MHz.
基金Supported by Natural Science Research Projects of Colleges and Universities in Anhui Province(KJ2019A1180,KJ2018A0884,KJ2017A772)
文摘[Objectives] To optimize the extraction of total flavone in folium Ginkgo biloba leaves.[Methods] Using the ultrasonic extraction method, the three levels of maximum impact were selected by each factor selection, and the optimal extraction technology was obtained by box-benhnken test design analysis.[Results] After analyzing the results, the optimal process was as follows: a time of 28.89 min and liquid/material ratio of 31.38∶ 1, the temperature was 40.74℃. In this way, NaNO 2-Al (NO 3) 3-NaOH was used as color developing agent, and the theoretical extraction of flavone in ginkgo leaf can reach 11.74 mg/g.[Conclusions] This method can be used to extract total flavonoids from G. biloba leaves with simple operation, low cost and good repeatability.
文摘A novel technique for reducing reverberation artifact in acoustic shadow imaging using nonlinear ultrasound interaction, called nonlinear acoustic shadow method, has been developed and experimentally studied. In this technique, the conventional acoustic shadow method is modified by using the secondary wave generated by nonlinear interaction of two primary sound waves emitted from parametric array. Either conventional or nonlinear acoustic shadow imaging is carried out for aluminum square cylinder and the size of the shadow is compared. The result shows that the nonlinear acoustic shadow method reduces reverberation artifact inside the square cylinder and has better accuracy in the size measurement than conventional acoustic shadow method.
